CN113945950B - Electronic equipment and depth detection devices - Google Patents

Abstract

The application provides an electronic device and a depth detection device, wherein the electronic device comprises: a housing; the display screen is covered on the shell and comprises a display module and a circular polaroid arranged on the display side of the display module, wherein the circular polaroid comprises a 1/4 wave plate and a linear polaroid which are sequentially arranged from the inner side to the outer side of the shell; the depth detection device comprises a projector and a receiver, wherein the projector and the receiver are arranged in the shell, the projector is used for emitting light outwards through the circular polaroid, the projector comprises a plurality of light sources which are distributed in an array, the light emitted by each light source is polarized light with the same polarization state, the vibration long axis of the polarized light is parallel to the optical axis of the 1/4 wave plate, and the receiver is used for receiving the reflected light of the light emitted outwards by the projector. The electronic equipment provided by the embodiment of the application can reduce the attenuation degree of the emergent light of the light emitted by the projector after passing through the circular polarizer, so that the signal of the reflected light received by the receiver is stronger, and the depth information determined by the depth detection device is more accurate.

Description

Electronic equipment and depth detection devices

Technical field

The present application relates to the technical field of electronic products, and in particular to an electronic device and a depth detection device.

Background technique

As the functions of electronic devices such as mobile phones increase, front-facing cameras are used in more and more application scenarios, for example, for photography, facial recognition, object recognition, etc. In order to better realize these functions, a depth detection device can be set up to obtain the depth information of the object, so as to achieve three-dimensional imaging in combination with the front camera. The depth detection device includes a projector and a receiver. The projector usually includes a light source array. The light source array projects light into the environment and is reflected by the object back to the receiver. The receiver determines the depth information of the object based on the received light signal.

In order to achieve a hole-free ultra-narrow bezel screen design as much as possible to improve the user's visual experience, the depth detection device is usually located inside the display screen, and the light emitted by the light source array needs to be emitted through the display screen into the external environment. In order to prevent the display screen from reflecting ambient light and affecting the display effect, the light-emitting side of the display screen is usually equipped with a circular polarizer.

However, after the light emitted by the light source array of the depth detection device passes through the circular polarizer, it will be absorbed by the circular polarizer by about 50%, which will cause a large attenuation of the light emitted by the light source array, resulting in the optical signal received by the receiver. Weak, resulting in a large error in the depth information determined by the depth detection device.

Contents of the invention

This application provides an electronic device and a depth detection device that can reduce the attenuation degree of the light emitted by the projector when it is emitted to the external environment, thereby enhancing the light signal received by the receiver, making the depth information determined by the depth detection device more accurate. .

In a first aspect, this application provides an electronic device, including:

case;

A display screen, covered on the casing. The display screen includes a display module and a circular polarizer located on the display side of the display module. The circular polarizer includes a display screen from the inside to the outside of the casing. 1/4 wave plate and linear polarizer set in sequence;

The depth detection device includes a projector and a receiver provided in the housing. The projector is used to emit light outward through the circular polarizer. The projector includes a plurality of light sources distributed in an array, each of which is The light emitted by the light source is polarized light with the same polarization state. The long axis of vibration of the polarized light is parallel to the optical axis of the 1/4 wave plate. The receiver is used to receive the light emitted outwardly by the projector. reflected light.

The display module can be an LED display module, an LCD display module, an OLED display module, a touch panel-liquid crystal display (TP-LCD) display module, a quantum dot display module, etc., but is not limited thereto.

OLED display modules are increasingly widely used in mobile phones, smart watches, tablets, etc. due to their advantages such as thin thickness, light weight, large viewing angle, fast response time, low energy consumption, and good bendability. on electronic equipment. Therefore, the display module of the electronic device in the embodiment of the present application can be an OLED display module, so as to make the electronic device lighter and thinner, with a larger viewing angle and longer battery life, thus improving the appearance and usability of the electronic device. User experience is better.

The above-mentioned 1/4 wave plate and linear polarizer are stacked. The 1/4 wave plate and the linear polarizer can be bonded and fixed through optical glue, or through other glues with higher light transmittance (epoxy resin glue, instant glue, etc.), but are not limited to this.

The above-mentioned linear polarizer has an absorption axis and a transmission axis that are perpendicular to each other. The linear polarizer can absorb the component of the incident light that is parallel to the absorption axis and transmit the component of the incident light that is parallel to the transmission axis. The incident light passes through the linear polarizer. Finally, linearly polarized light with a polarization direction parallel to the transmission axis of the linearly polarizing plate can be formed.

The above-mentioned 1/4 wave plate is also called a compensation film or a phase difference film. Its function is to realize the conversion of the polarization state of light. The 1/4 wave plate has a fast axis and a slow axis that are perpendicular to each other. The fast axis and the slow axis are both 1/ The optical axis of the 4-wave plate. When linearly polarized light is vertically incident on the 1/4-wave plate, if the angle θ between the polarization direction of the linearly polarized light and the optical axis (fast axis or slow axis) of the 1/4-wave plate is 45°, then the emergent light is For circularly polarized light, if the angle θ between the polarization direction of the linearly polarized light and the optical axis of the quarter wave plate is not 45°, the emitted light will be elliptically polarized light.

In order to make the ambient light pass through the linear polarizer and the 1/4 wave plate to form circularly polarized light, so as to achieve complete absorption of the reflected light of the external ambient light through the circular polarizer, the optical axis of the 1/4 wave plate (fast axis/ The angle between the slow axis) and the transmission axis of the linear polarizer is usually 45°.

The directions of the fast axis and the slow axis are usually marked on the 1/4 wave plate. The directions of the transmission axis and the absorption axis are usually marked on the linear polarizer. When manufacturing the circular polarizer, you can directly follow the directions marked on the 1/4 wave plate. The directions of the fast axis and the slow axis, and the directions of the transmission axis and the absorption axis marked on the linear polarizer, set the relative positions between the two, so that the optical axis of the 1/4 wave plate is consistent with the transmission axis of the linear polarizer. The angle between them is 45°.

The above-mentioned depth detection device may be a time of flight (TOF) depth detection device or a 3D structured light depth detection device, but is not limited thereto.

In the embodiment of the present application, the projector and the receiver can be installed on the middle frame of the casing, on the main board, or on other components inside the casing. The projector and the receiver can be electrically connected to the mainboard of the electronic device respectively. The mainboard can be electrically connected to a processor. The projector and the receiver can be electrically connected to the processor through the mainboard to control the opening and closing status of the projector through the processor. Control, and use the processor to process the emitted light signal received by the receiver to determine the depth information of the external object.

In the embodiments of this application, the polarization state of the light emitted by each light source is the same means that the light emitted by each light source has the same polarization type and the polarization direction.

The types of light emitted by the light source usually include: linearly polarized light, circularly polarized light and elliptically polarized light. Among them, the trajectory of the endpoint of the light vector of linearly polarized light is a straight line, that is, the light vector only vibrates along a certain direction. The trajectory of the light vector endpoint of elliptically polarized light is an ellipse, that is, the light vector continuously rotates, and the size and direction of the light vector change regularly with time. The trajectory of the endpoint of the light vector of circularly polarized light is a circle, that is, the light vector continuously rotates, its size remains unchanged, but its direction changes regularly with time.

Linearly polarized light and circularly polarized light can also be understood as special forms of elliptically polarized light. When the amplitude of the short axis of vibration of elliptically polarized light is 0, it is linearly polarized light. When the amplitude of the long axis of vibration of elliptically polarized light is equal to the amplitude of the short axis of vibration, When equal, it is circularly polarized light.

The light emitted by each light source of the light source array may be linearly polarized light with the same polarization direction, or circularly polarized light with the same polarization direction, or elliptically polarized light with the same polarization direction.

The amplitude of the light emitted by each light source can be the same or different. When the amplitude of the light emitted by each light source is the same, the light emitted by the projector can be more uniform, so that the depth of the object to be measured can be detected more accurately, and the structure of the projector can be simpler and more compact.

Linearly polarized light with the same polarization direction means that the vibration directions of each linearly polarized light are parallel. The amplitudes of linearly polarized lights with parallel vibration directions may or may not be equal.

Elliptically polarized light with the same polarization direction means that each elliptically polarized light has the same rotation direction and the long axis of vibration is parallel. The vibration long-axis amplitude values of each elliptically polarized light may be the same or different, and the vibration short-axis amplitude values of each elliptically polarized light may be the same or different. Each elliptically polarized light has the same rotation direction, and each elliptically polarized light may be left-handed elliptically polarized light, or each elliptically polarized light may be right-handed elliptically polarized light.

Circularly polarized light with the same polarization direction means that each circularly polarized light has the same rotation direction. Each circularly polarized light may be all left-handed circularly polarized light, or all may be right-handed circularly polarized light. The amplitude values of each circularly polarized light may be the same or different.

The long axis of vibration of polarized light refers to the axis with the largest amplitude among the vibration directions of polarized light. For linearly polarized light, since its vibration direction is always along the same straight line, the vibration long axis direction of the linearly polarized light is the polarization direction of the linearly polarized light. For elliptically polarized light, its vibration amplitude in each direction undergoes elliptical transformation, and the vibration direction with the largest amplitude is the direction of its long axis of vibration. For circularly polarized light, since the amplitudes of each polarization direction of circularly polarized light are equal, any diameter direction of circularly polarized light is the vibration major axis direction of circularly polarized light.

In the electronic device provided by the embodiment of the present application, since the polarization state of the light emitted by each light source of the projector is the same, and the long axis of vibration of the polarized light emitted by the light source is parallel to the optical axis of the 1/4 wave plate, each light source emits The emitted light can form linearly polarized light after passing through the 1/4 wave plate of the circular polarizer. The formed linearly polarized light is more likely to pass through the linear polarizer of the circular polarizer at a larger proportion, thus allowing the light source to pass through the circularly polarized light. The attenuation of the emitted light behind the chip is smaller, making the reflected light signal received by the receiver stronger, thereby making the depth information determined by the depth detection device more accurate.

In an optional design, the transmission axis of the linear polarizer is rotated 45° clockwise relative to the fast axis of the 1/4 wave plate, and the light emitted by the light source is right-handed polarized light, so The right-handed polarized light is right-handed elliptically polarized light or right-handed circularly polarized light.

Optionally, when the above-mentioned right-handed circularly polarized light is right-handed circularly polarized light, the right-handedly circularly polarized light emitted by the light source can be made to pass through the circular polarizer and the emission ratio reaches 100%, so that the light emitted by the projector can be transmitted through the circular polarizer. There is no light loss behind the polarizer, so that the light emitted from the light source array will not be attenuated by the circular polarizer.

When the right-handed polarized light is right-handed elliptical polarized light, the output ratio of the light emitted by the light source after passing through the circular polarizer reaches about 85%.

This design can significantly increase the amount and emission ratio of light emitted by the projector after passing through the circular polarizer, improve the intensity of the light signal received by the receiver, and make the depth information determined by the depth detection device more accurate.

In an optional design, the transmission axis of the linear polarizer is rotated 45° counterclockwise relative to the fast axis of the 1/4 wave plate, and the light emitted by the light source is left-handed polarized light. Left-handed polarized light is left-handed elliptically polarized light or left-handed circularly polarized light.

Optionally, when the above-mentioned left-handed circularly polarized light is left-handed circularly polarized light, the left-handedly circularly polarized light emitted by the light source can be made to pass through the circular polarizer and the emission ratio reaches 100%, so that the light emitted by the projector can pass through the circular polarizer. After exiting without light loss.

When the right-handed polarized light is left-handed elliptical polarized light, the light emitted by the light source can be transmitted through the circular polarizer and the emission ratio reaches about 85%.

This design can also significantly increase the amount and emission ratio of light emitted by the projector after passing through the circular polarizer, making the depth information determined by the depth detection device more accurate.

In an optional design, the angle between the transmission axis of the linear polarizer and the fast axis of the 1/4 wave plate is 45°, and the light emitted by the light source is linearly polarized light, so The vibration direction of the linearly polarized light is parallel to the optical axis of the quarter wave plate.

In this design, the emission ratio of the linearly polarized light emitted by the projector is about 71%. It can also significantly increase the amount and emission ratio of the light after passing through the circular polarizer, thereby increasing the intensity of the optical signal received by the receiver. , making the depth information determined by the depth detection device more accurate.

In an optional design, the electronic device also includes:

The glass cover plate, the display module, the circular polarizer and the glass cover plate are stacked on the casing in sequence.

The display screen can be a rigid screen or a foldable screen (flexible screen).

The glass cover in this design can better protect the display module and circular polarizer.

In an optional design, the electronic device also includes:

A camera is provided in the housing and faces the glass cover. The display module and the circular polarizer are provided with a through hole for the camera to receive external light. The camera is adjacent to the depth detection device. set up.

In this design, the camera facing the glass cover can also be called the front camera. The display module and the circular polarizer can be provided with a through hole directly facing the camera, so that external light can pass through the through hole to the camera, so that the camera can image clearly.

In this design, the depth detection device and the front camera can be combined to form a three-dimensional imaging device. The depth detection device is used to obtain the depth information of external objects. The front camera is used to obtain the plane information of external objects. The processor can obtain the plane information of the external object based on the depth information and the plane. The information forms a three-dimensional image of the external object.

In this embodiment, since the front camera and the depth detection device are arranged adjacent to each other, it is easier for the front camera and the depth detection device to align the same object more accurately, thereby making the generated three-dimensional image more consistent with the real object and the imaging more accurate.

In other optional designs, the distance between the camera and the depth detection device can also be set according to the actual needs of the electronic device. For example, the distance between the camera and the depth detection device can also be set farther to ensure that the electronic device The structure is more compact, and the embodiment of the present application does not limit the specific distance between the camera and the depth detection device.

In an optional design, the light source is any one of a vertical cavity surface emitting laser, a laser diode, and a light emitting diode.

Among them, vertical cavity surface emitting lasers are increasingly used in projectors due to their advantages of small size, low power consumption, high beam quality, small divergence angle, and circularly symmetric light field distribution. Therefore, embodiments of the present application The light source included in the mid-projector may be a vertical cavity surface emitting laser.

In an optional design, the projector further includes: a light uniforming device provided on the light exit side of the light source.

The above-mentioned uniform light device is used to adjust the energy distribution of the light beam emitted by the light source to obtain a uniform light beam.

Through uniform light processing, the optical power of the light beam emitted by the light source can be made more uniform, which can prevent the local optical power from being too small and avoid blind spots in the final depth map of the object.

Optionally, the uniform light device may be a diffractive optical element.

The function of diffractive optical elements is to shape the light beam emitted by the light source array into more uniform light. Specifically, diffractive optical elements can be used to shape the light beam emitted by the light source array into a uniform square light source or a uniform rectangular light source with a certain viewing angle field FOV.

In this embodiment, diffractive optical elements can be used to make the light projected by the projector more uniform, thereby making depth detection more accurate. And because the optical diffraction element can shape the light beam into a uniform shape with a certain viewing angle field, the light projected by the projector can be more accurately aimed at the object to be detected.

Optionally, the above-mentioned light uniforming device may also be a microlens array.

The above-mentioned microlens array can be a microlens diffuser. The microlens array can achieve uniform light based on geometric optics, and its transmission efficiency can reach more than 80%. It is composed of a series of microlenses distributed in an array. The microlens array is used for Shaping the light emitted by the light source array makes the shaped light beam more uniform, thereby making the light projected by the projector more uniform and making the depth detection more accurate.

Each microlens in the microlens array can be distributed in a regular array. For example, each microlens can be distributed in a rectangular, circular, regular polygon, or linear array, and the distance between every two adjacent microlenses is equal. Alternatively, each microlens in the microlens array may be distributed in an irregular array. For example, each microlens may be distributed in an asymmetric pattern array, and the distance between every two adjacent microlenses is not exactly equal. This application does not limit the specific distribution mode of the microlens array.

In an optional design, the light emitted by the light source is infrared light, and the wavelength of the infrared light is greater than 830 nanometers.

For example, the wavelength of the light emitted by the light source can be 840, 900, 940 nanometers, 980 nanometers, 1000 nanometers, etc., but is not limited thereto. Since the intensity of light greater than 830 nanometers in ambient light is relatively weak, when the wavelength of light emitted by the light source is greater than 830 nanometers, it helps to reduce the interference caused by ambient light on depth detection, thereby improving the detection accuracy of the depth detection device. Rate.

In an optional design, the receiver includes a condensing lens and a photoelectric sensor located on the light exit side of the condensing lens.

The light exit side of the condensing lens is the side of the condensing lens facing away from the circular polarizer.

The above-mentioned condensing lens may include one or multiple stacked ones. The condensing lens has a converging effect on light. The converging lens is used to converge the reflected light of the light emitted outwardly by the projector, so that the reflected light can be reflected more It is received by the photoelectric sensor of the receiver to detect more depth information of the object to be detected, making the depth detection more accurate.

In an optional design, the receiver may also include:

An optical filter is provided between the condensing lens and the photoelectric sensor, and is used to filter light other than infrared light in the incident light.

Since the light emitted by the light source of the projector is usually infrared light, this embodiment uses a filter to filter out light other than infrared light in the ambient light, which can reduce the interference caused by ambient light on depth detection, thereby improving depth detection. The detection accuracy of the device.

In a second aspect, embodiments of the present application also provide a depth detection device for installation in a housing of an electronic device, characterized in that the depth detection device includes:

The projector is used to emit light through the circular polarizer of the electronic device. The projector includes a plurality of light sources distributed in an array. The light emitted by each of the light sources is polarized light with the same polarization state. When the When the depth detection device is installed in the housing, the vibration long axis of the polarized light is parallel to the optical axis direction of the 1/4 wave plate of the circular polarizer;

The receiver is used for receiving the reflected light of the light emitted outwardly by the projector.

In an optional design, the light source is any one of a vertical cavity surface emitting laser, a laser diode, and a light emitting diode.

In an optional design, the projector further includes: a light uniforming device provided on the light exit side of the light source.

In an optional design, the uniform light device is a diffractive optical element or a microlens array.

In an optional design, the light emitted by the light source is infrared light, and the wavelength of the infrared light is greater than 830 nanometers.

In an optional design, the receiver includes a condensing lens and a photoelectric sensor located on the light exit side of the condensing lens.

In an optional design, the receiver also includes:

An optical filter is provided between the condensing lens and the photoelectric sensor, and is used to filter light other than infrared light in the incident light.

Since the depth detection device has the same structure as the depth detection device included in the above-mentioned electronic equipment, the technical effects brought by the depth detection device to the electronic equipment are the same as those of the above-mentioned electronic equipment, and will not be described again here.

Description of the drawings

Figure 1 is a schematic diagram of the working principle of a circular polarizer;

Figure 2 is a schematic diagram of the light source array of the depth detection device emitting elliptically polarized light with different polarization states;

Figure 3 is a schematic diagram of the overall structure of an example of an electronic device provided by an embodiment of the present application;

FIG. 4 is a cross-sectional view of the electronic device shown in FIG. 3 taken from the A-A perspective;

Figure 5 is an exploded schematic diagram of the electronic device shown in Figure 3;

Figure 6 is a schematic structural diagram of the projector of the electronic device shown in Figure 3;

Figure 7 is a schematic structural diagram of the receiver of the electronic device shown in Figure 3;

Figure 8 is an angular relationship diagram between the optical axis of the 1/4 wave plate of the circular polarizer and the transmission axis of the linear polarizer in the electronic device shown in Figure 3;

Figure 9 is a schematic diagram of the light beams emitted by each light source in the electronic device shown in Figure 3 passing through the circular polarizer;

Figure 10 is a schematic diagram of another example of the electronic device provided by the embodiment of the present application, in which the light beams emitted by each light source pass through the circular polarizer;

FIG. 11 is a schematic diagram of light beams emitted from each light source passing through a circular polarizer in yet another example of the electronic device provided by the embodiment of the present application;

Figure 12 is a schematic structural diagram of the light source array in the electronic device shown in Figure 3;

Figure 13 is a schematic structural diagram of a light source array of another example of an electronic device provided by an embodiment of the present application;

Figure 14 is a schematic structural diagram of a light source array of another example of the electronic device provided by the embodiment of the present application;

Figure 15 is a schematic structural diagram of a light source array of another example of the electronic device provided by the embodiment of the present application;

Figure 16 is a schematic structural diagram of a light source array of another example of the electronic device provided by the embodiment of the present application;

Figure 17 is a schematic structural diagram of a light source array of another example of the electronic device provided by the embodiment of the present application;

Figure 18 is a schematic diagram of the relationship between the optical axis of the 1/4 wave plate and the coordinate axis of left-handed circularly polarized light;

Figure 19 is a schematic diagram of the polarized light emitted when θ is 0° in Figure 18;

Figure 20 is a schematic diagram of the emitted ray-polarized light when θ is 0° in Figure 18 and the incident light is right-handed circularly polarized light;

Figure 21 is a schematic diagram of the polarized light emitted when θ is 45° in Figure 18;

Figure 22 is a schematic diagram of the emitted linearly polarized light when θ is 45° in Figure 18 and the incident light is right-handed circularly polarized light;

Figure 23 is a diagram of the correspondence between the rotation direction of the circularly polarized light emitted by the light source in the electronic device shown in Figure 3 and the optical axis of the 1/4 wave plate;

Figure 24 is a diagram of the correspondence between the rotation direction of the circularly polarized light emitted by the light source and the optical axis of the quarter wave plate in another example of the electronic device provided by the embodiment of the present application;

Figure 25 is a diagram showing the angular relationship between the linearly polarized light emitted after right-handed elliptically polarized light passes through the 1/4 wave plate and the optical axis of the 1/4 wave plate;

Figure 26 is a diagram showing the angular relationship between the linearly polarized light emitted after the left-handed elliptically polarized light passes through the 1/4 wave plate and the optical axis of the 1/4 wave plate.

Reference signs:

10. Display screen; 11. Circular polarizer; 11a, 1/4 wave plate; 11b, linear polarizer; 11c, through hole; 12. Display module; 12a, through hole; 13. Glass cover;

20. Depth detection device; 21. Projector; 211. Light source array; 211a, light source; 212. Light uniformity device; 22. Receiver; 221. Converging lens; 222. Photoelectric sensor; 223. Optical filter;

50. Camera; 60. Motherboard; 70. Housing; 71. Frame; 72. Middle frame; 73. Back cover; 80. Mounting plate.

Detailed ways

The technical solutions in this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments.

In the description of this application, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be mechanical connection, electrical connection or mutual communication; it can be direct connection, or indirect connection through an intermediary, it can be internal connection of two elements or interaction of two elements relation. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

In the description of this application, it should be understood that the terms "upper", "lower", "side", "inner", "outer", "top", "bottom", etc. indicate an orientation or positional relationship based on the installation The orientation or positional relationship is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. .

It should also be noted that in the embodiments of the present application, the same reference numerals refer to the same components or components. For the same components in the embodiments of the present application, only one of the parts or components may be labeled as an example in the figure. Where reference numerals are used, it should be understood that the same reference numerals apply to other identical parts or components.

Hereinafter, the terms “first”, “second”, etc. are used for descriptive purposes only and shall not be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, features defined by "first," "second," etc. may explicitly or implicitly include one or more of such features.

In the description of this application, it should be noted that the term "and/or" is only an association relationship describing associated objects, indicating that there can be three relationships, for example, A and/or B, which can mean: existing alone A, A and B exist at the same time, and B alone exists.

It should also be noted that in the embodiments of the present application, the same reference numerals refer to the same components or components. For the same components in the embodiments of the present application, only one of the parts or components may be labeled as an example in the figure. Where reference numerals are used, it should be understood that the same reference numerals apply to other identical parts or components.

Display modules are essential components of electronic devices with display functions. With the update and development of electronic products, more and more types of display modules have appeared. For example, liquid crystal display (LCD) display module, organic light emitting diode (OLED) display module, quantum dot display module, light emitting diode (LED) display module, etc. Display modules usually have a certain reflectivity.

The following uses an OLED display module as an example to explain the reflection of the display module.

OLED display modules usually have an anode layer, an organic light-emitting layer, a cathode layer, etc. formed sequentially on a glass substrate. The material of the anode layer is usually indium tin oxide (ITO), and the material of the cathode layer is usually magnesium-silver alloy.

Since the cathode layer of the OLED display module is made of metal material, it easily reflects external ambient light. The reflected ambient light entering the human eye will reduce the contrast of the display module, thereby affecting the display effect. For example, when a user watches the content on the screen under the sun, the user cannot see the screen content clearly due to the reflection of sunlight by the cathode layer.

To solve this problem, a circular polarizer (CPOL) can be attached to the display side of the display module. Circular polarizers use the principle of polarized light to effectively prevent the reflection intensity of external ambient light on the screen. The circular polarizer includes a 1/4 (quarter) wave plate and a linear polarizer located outside the 1/4 wave plate. The outside of the 1/4 wave plate is the side of the 1/4 wave plate facing away from the display module. .

Figure 1 is a schematic diagram of the working principle of a circular polarizer. As shown in Figure 1, after the external ambient light passes through the linear polarizer with the absorption axis in the vertical direction, only half of the horizontal linearly polarized light remains. After the horizontal linearly polarized light passes through the 1/4 wave plate, it is converted into left-handed circularly polarized light. After the light is reflected by the display module, it is rotated 180° and becomes right-handed circularly polarized light. After the right-handed circularly polarized light passes through the 1/4 wave plate, it is converted into vertical linearly polarized light. The vertically linearly polarized light cannot pass through the absorption axis and is in the vertical direction. The linear polarizer cannot emit light, thus effectively preventing external ambient light from being reflected on the screen and then emitted. Through the above steps, the reflected light of the external ambient light can be blocked in the circular polarizer, thereby greatly improving the contrast of the display module itself and improving the outdoor viewing performance of the display module, even under strong sunlight. Clearly see the contents of the screen.

As the functions of electronic devices such as mobile phones and tablets increase, front-facing cameras are used in more and more application scenarios, such as for shooting, facial recognition, object recognition, etc. In order to better realize these functions, a depth detection device can be set up to obtain the depth information of the object, so as to achieve three-dimensional imaging in combination with the front camera. The depth detection device includes a projector and a receiver. The projector includes a light source array. The light source array projects light into the environment and is reflected back to the receiver by objects in the environment. The receiver determines the depth information of the object based on the received reflected light signal. .

In order to achieve a hole-free ultra-narrow screen design for electronic devices and improve the user's visual experience, the depth detection device is usually located inside the display module. The inside of the display module is the side of the display module facing away from the display side. , the light emitted by the projector of the depth detection device needs to be emitted to the external environment through the display module and the circular polarizer located outside the display module.

In the related art, the light emitted by the light source array usually includes polarized light with different polarization states. That is, the polarization states of the light emitted by each light source of the light source array are usually different. For example, the light emitted by each light source may include circularly polarized light, elliptically polarized light, linearly polarized light, etc. with different polarization states. After these polarized lights with different polarization states pass through the 1/4 wave plate of the circular polarizer, they are usually still polarized lights with different polarization states. When they pass through the linear polarizer of the circular polarizer, only the component perpendicular to the absorption axis can When emitted, the component parallel to the absorption axis will be absorbed by the linear polarizer and cannot be emitted. Therefore, the emitted light after passing through the linear polarizer will usually lose about 50%.

Below, the reason why about 50% of the light emitted by the light source array is lost when passing through the circular polarizer will be explained through specific examples.

Figure 2 is a schematic diagram of the light source array of the depth detection device emitting elliptically polarized light with different polarization states.

As shown in Figure 2, each light source 211a emits elliptically polarized light with different polarization states and passes through a circular polarizer. The polarization state of the light emitted by each light source 211a remains unchanged after passing through the display module, and then passes through the circularly polarized light. After passing through the 1/4 wave plate of the linear polarizer, the emitted light is usually still elliptically polarized light, such as the three beams of light in Figure 2. The emission ratio of these three beams of elliptically polarized emitted light after passing through the linear polarizer is, for example, as shown in Figure 2 The ratios shown are 50%, 65%, and 30%. This ratio can be calculated through experimental tests. This is only an example. The average value of each different emission ratio is approximately 50%. The exit ratio refers to the ratio of the intensity of the exit light after passing through the linear polarizer to the intensity of the incident light when it enters the linear polarizer.

Referring again to Figure 1, when the light emitted by the light source array includes circularly polarized light, the circularly polarized light includes both left-hand circularly polarized light and right-hand circularly polarized light, because only left-hand circularly polarized light can pass through the 1/4 wave plate. It is completely emitted from the linear polarizer, while the right-handed circularly polarized light is completely absorbed after passing through the 1/4 wave plate, so the emission ratio is about 50%.

When the light emitted by the light source array includes linearly polarized light, the linearly polarized light usually forms elliptically polarized light after passing through the 1/4 wave plate, and the output ratio of the elliptically polarized light after passing through the linear polarizer is usually about 50%.

It can be seen that after the light emitted by the light source array of the projector passes through the circular polarizer, it will usually be absorbed by the circular polarizer by about 50%, that is, it will be lost by about 50%. This will cause a large attenuation of the emitted light from the light source array, causing the receiver to The received optical signal is weak, resulting in a large error in the depth information determined by the depth detection device.

In response to the above problems, the present application provides an electronic device that can reduce the degree of attenuation of the light emitted by the projector 21 when it is emitted to the external environment by adjusting the polarization state of each light source 211a of the projector 21, thereby enhancing the sensitivity of the receiver. The optical signal received by 22 makes the depth information determined by the depth detection device 20 more accurate.

The electronic device may be a mobile phone (for example, an ordinary mobile phone or a foldable mobile phone), a tablet computer, a notebook computer, a desktop computer, a smart watch, a personal digital assistant (personal digital assistant, PDA), or a point of sales terminal (POS). , car computers, TVs and other equipment, but not limited to these, this electronic equipment has a depth detection function.

Please refer to FIGS. 3 to 5 . FIG. 3 is a schematic diagram of the overall structure of an example of an electronic device provided by an embodiment of the present application. FIG. 4 is a cross-sectional view of the electronic device shown in FIG. 3 from a perspective A-A. FIG. 5 is a schematic view of the electronic device shown in FIG. 3 Exploded illustration of electronic equipment.

In FIGS. 3 to 5 , the electronic device includes: a housing 70 and a display screen 10 . The display screen 10 is mounted on the housing 70 . The electronic device also includes electronic components arranged inside the housing 70. The electronic components include the depth detection device 20, the motherboard 60, the processor, the camera 50, the flash, the microphone, the battery, etc. (only some electronic components are shown in the figure), but not Limited to this.

The housing 70 may be a metal housing, such as a magnesium alloy, stainless steel, or other metal housing. In addition, the housing can also be a plastic housing, a glass housing, a ceramic housing, etc., but is not limited thereto. The casing 70 may include a frame 71 and a back cover 73 . The back cover 73 covers the frame 71 . The casing 70 may be provided with a middle frame 72 . The middle frame 72 can be reflectively fixed in the frame 71 through bonding, snapping, threaded connection, etc., and the housing 70 can also be formed into an integrated structure with the frame 71 through an integral molding process such as injection molding. A storage space can be formed between the middle frame 72, the back cover 73 and the frame 71, and the above-mentioned electronic components can be installed in the storage space. Alternatively, the middle frame 72 can be provided with a mounting slot, and the above-mentioned electronic components can be installed in the mounting slot. .

The display screen 10 may include a display module 12 , a circular polarizer 11 and a glass cover 13 that are stacked in sequence from the inside to the outside of the housing 70 . The display screen 10 may be a rigid screen or a foldable screen (flexible screen). The circular polarizer 11 covers the display module 12 , and the glass cover 13 covers the circular polarizer 11 . The glass cover 13 can better protect the display module 12 and the circular polarizer 11 and prevent the display module 12 from being damaged by external forces, thereby improving the structural reliability of the electronic device.

The display module 12 may be an LED display module 12, an LCD display module 12, an OLED display module 12, a touch panel-liquid crystal display (TP-LCD) display module 12, or a quantum dot display module 12 etc., but not limited to this. In addition, the display screen 10 may also be a folding screen (flexible screen).

Among them, OLED display module 12 is increasingly widely used in mobile phones, smart watches, and tablets due to its advantages such as thin thickness, light weight, large viewing angle, fast response time, low energy consumption, and good bendability. on computers and other electronic devices. Therefore, the display module 12 of the electronic device in the embodiment of the present application may be an OLED display module 12, so as to make the electronic device thinner, lighter, have a larger viewing angle, and have a longer battery life, thus improving the appearance and use of the electronic device. performance, user experience is better.

As shown in FIGS. 4 and 5 , the circular polarizer 11 includes a quarter wave plate 11 a and a linear polarizer 11 b that are arranged sequentially from the inside to the outside of the housing 70 . The quarter wave plate 11 a and the linear polarizer 11 b are stacked. , the 1/4 wave plate 11a and the linear polarizer 11b can be bonded and fixed through optically clear adhesive (OCA), or through other glues with high light transmittance (epoxy resin glue, instant glue). glue, etc.) for bonding and fixation.

Optical adhesive is a double-sided laminating tape without a matrix material. It has the characteristics of colorless transparency, high light transmittance (total light transmittance >99%), high adhesion, high temperature resistance, UV resistance, etc., and is resistant to The controlled thickness can provide uniform spacing and will not cause yellowing, peeling or deterioration problems after long-term use.

In the embodiment of the present application, the 1/4 wave plate 11 a and the linear polarizer 11 b are arranged in sequence from the inside to the outside of the housing 70 , that is, the 1/4 wave plate 11 a is arranged on the light exit side of the display module 12 , and the linear polarizer 11 b It is arranged on the side of the quarter wave plate 11a facing away from the display module 12 .

The above-mentioned linear polarizer 11b has an absorption axis and a transmission axis that are perpendicular to each other. The linear polarizer 11b can absorb the component of the incident light that is parallel to the absorption axis, and transmits the component of the incident light that is parallel to the transmission axis. The incident light passes through the line. After the polarizer 11b is connected, linearly polarized light with a polarization direction parallel to the transmission axis of the linearly polarizer 11b can be formed.

The above-mentioned 1/4 wave plate 11a is also called a compensation film or a retardation film. Its function is to realize the conversion of the polarization state of light. The 1/4 wave plate 11a has a fast axis and a slow axis that are perpendicular to each other. The fast axis and the slow axis are both The optical axis of the quarter wave plate 11a. When linearly polarized light is vertically incident on the quarter-wave plate 11a, if the angle θ between the polarization direction of the linearly polarized light and the optical axis (fast axis or slow axis) of the quarter-wave plate 11a is 45°, then the output The emitted light is circularly polarized light. If the angle θ between the polarization direction of the linearly polarized light and the optical axis of the quarter wave plate 11a is not 45°, the emitted light is elliptically polarized light.

FIG. 8 is an angular relationship diagram between the optical axis of the quarter-wave plate 11a of the circular polarizer 11 and the transmission axis of the linear polarizer 11b in the electronic device shown in FIG. 3 . In order to make the ambient light pass through the linear polarizer 11b and the 1/4 wave plate 11a to form circularly polarized light, so as to achieve complete absorption of the reflected light of the external ambient light through the circular polarizer 11, as shown in Figure 8, 1/4 The angle between the optical axis (fast axis/slow axis) of the wave plate 11a and the transmission axis of the linear polarizer 11b is usually 45°. Specifically, the angle between the transmission axis of the linear polarizer 11b and the 1/4 wave plate 11a The angle between the fast axes can be ±45°, where clockwise rotation of the transmission axis around the fast axis is positive and counterclockwise rotation is negative.

The directions of the fast axis and the slow axis are usually marked on the 1/4 wave plate 11a, and the directions of the transmission axis and the absorption axis are usually marked on the linear polarizer 11b. When manufacturing the circular polarizer 11, the directions of the 1/4 wave plate 11 can be directly marked. The directions of the fast axis and the slow axis marked on the plate 11a, and the directions of the transmission axis and the absorption axis marked on the linear polarizing plate 11b are set relative to each other so that the direction of the quarter wave plate 11a is The angle between the optical axis and the transmission axis of the linear polarizer 11b is 45°.

The circular polarizer 11 and the display module 12 and the circular polarizer 11 and the glass cover 13 can be fixed by colloid bonding. The colloid can be optical glue or ordinary glue such as epoxy resin glue or instant glue. , but not limited to this.

As shown in FIGS. 4 and 5 , the display screen 10 can be fixed on the middle frame 72 . Specifically, the inner surface of the display screen 10 can be bonded to the middle frame 72 through optical glue, latex, epoxy resin glue or other colloids. The inner surface of the display screen 10 is the surface of the display screen 10 facing the inner cavity of the housing 70. The display The inner surface of the screen 10 is generally the surface of the display module 12 facing the inner cavity of the housing 70 .

The depth detection device 20 may be a time of flight (TOF) depth detection device 20 or a 3D structured light depth detection device 20, but is not limited thereto.

As shown in FIGS. 3 to 5 , the above-mentioned depth detection device 20 includes a projector 21 and a receiver 22 provided in the housing 70 . The projector 21 is used to emit light outward through the circular polarizer 11 . The projector 21 includes a There are multiple light sources 211a distributed in an array. The light emitted by each light source 211a is polarized light with the same polarization state. The direction of the long axis of vibration of the polarized light is parallel to the optical axis direction of the quarter wave plate 11a. The receiver 22 is used for The reflected light of the light emitted outwardly by the projector 21 is received.

In the embodiment of the present application, the projector 21 and the receiver 22 can be installed on the middle frame 72 , the mainboard 60 , or other components in the housing 70 , which are not specifically limited in this application. The projector 21 and the receiver 22 can be electrically connected to the mainboard 60 respectively. The mainboard 60 can be electrically connected to a processor. The projector 21 and the receiver 22 can be electrically connected to the processor through the mainboard 60 so that the projector 21 can be transmitted through the processor. The opening and closing state of the sensor is controlled, and the processor processes the emitted light signal received by the receiver 22 to determine the depth information of the external object.

The projector 21 and the receiver 22 can be fixed on the middle frame 72, the mainboard 60 or the casing 70 through snapping, bonding, riveting, plugging, threaded connection and other connection methods, and the specific connection method is not limited.

Specifically, as shown in FIGS. 4 and 5 , the projector 21 can be installed on the middle frame 72 through the mounting plate 80 . For example, the mounting plate 80 can be provided with a mounting hole, and the projector 21 can be fixed in the mounting hole. The inner surface of the mounting hole and the projector 21 can be bonded and fixed by dispensing glue or injecting glue, and the projector 21 can also be fixed. It can be snap-fitted or threadedly connected in the mounting hole; as another example, the projector 21 can also be directly fixed on the outer surface of the mounting plate 80 . The middle frame 72 can be provided with a mounting slot, and the mounting plate 80 is fixed in the mounting slot, thereby fixing the projector 21 and the receiver 22 on the middle frame 72 , or the mounting plate 80 can also be directly fixed outside the middle frame 72 . On the surface. The installation method of the receiver 22 can refer to the projector 21, and will not be described in detail in this application.

In this embodiment, both the projector 21 and the receiver 22 can be installed on the installation plate 80. In this way, the projector 21 and the receiver 22 can be assembled through the installation plate 80 first, and then the installation plate 80 can be installed on the middle frame 72. , thereby making it easier to install the depth detection device 20.

In the embodiment of the present application, the projector 21 and the receiver 22 are located on the side of the circular polarizer 11 facing the inner cavity of the housing 70 , and the projection end of the projector 21 and the receiving end of the receiver 22 face the circular polarizer 11 . The projection end of the projector 21 is the end through which the projector 21 emits light, and the receiving end of the receiver 22 is the end through which the receiver 22 receives external light.

When the display screen 10 includes the display module 12 , the projector 21 and the receiver 22 may be located on a side of the display module 12 facing the inner cavity of the housing 70 . In this embodiment, the projector 21 and the receiver 22 are arranged inside the display module 12. There is no need to make holes in the display module 12 and the circular polarizer 11, so that the display area of the display module 12 will not be affected. The integrity of the display screen 10 is better, and the integrity of the content displayed on the display screen 10 is also better, thereby improving the user's visual experience.

In a specific embodiment, as shown in FIGS. 3 to 5 , the above-mentioned camera 50 can be disposed in the housing 70 and faces the glass cover 13 , the display module 12 can be provided with a through hole 12 a, and the circular polarizer 11 can be provided with a through hole 12 a. A through hole 11c is provided, and the through hole 12a on the display module 12 is relatively connected to the through hole 11c on the circular polarizer for the camera 50 to receive external light. The camera 50 and the depth detection device 20 are arranged adjacent to each other. The camera 50 faces the glass cover 13 , that is, the front end (ie, the shooting end) of the camera 50 faces the glass cover 13 .

In the embodiment of the present application, the camera 50 facing the glass cover 13 may also be called the front camera 50 . The through holes provided on the display module 12 and the circular polarizer 11 can face the camera 50 so that external light can emit from the through holes to the camera 50 so that the camera 50 can image clearly.

In the embodiment of the present application, the depth detection device 20 and the front camera 50 can be combined to form a three-dimensional imaging device. The depth detection device 20 is used to obtain depth information of external objects, and the front camera 50 is used to obtain planar information of external objects. The processor A three-dimensional image of an external object can be formed based on depth information and plane information.

In a specific embodiment, as shown in FIGS. 4 and 5 , the front-facing camera 50 can be installed on the above-mentioned mounting plate 80 so as to be placed adjacent to the depth detection device 20 . The front camera 50 can also be directly installed on the middle frame 72 , the motherboard 60 or the casing 70 , and the specific installation method of the front camera 50 is not limited.

The front camera 50 and the depth detection device 20 are arranged adjacent to each other. The distance between the front camera 50 and the depth detection device 20 may be less than a specific distance. The specific distance may be any value from 1 mm to 10 mm, for example, a specific distance. It is 1 mm, 2 mm, 5 mm, 8 mm or 10 mm, etc., but is not limited to this. The distance between the front camera 50 and the depth detection device 20 may be determined according to the overall size of the electronic device.

In this embodiment, since the front camera 50 and the depth detection device 20 are arranged adjacent to each other, it is easier and more accurate for the front camera 50 and the depth detection device 20 to align the same object, thereby making the generated three-dimensional image more consistent with the real object. more acurrate.

The camera 50 and the depth detection device 20 can also work independently. For example, the camera 50 is used to collect two-dimensional graphics of an object, and the depth detection device 20 is used to collect the depth information of an object. Therefore, in other embodiments, the distance between the camera 50 and the depth detection device 20 can be set according to the actual structural layout of the electronic device. For example, the distance between the camera 50 and the depth detection device 20 can also be set farther. The application embodiment does not limit the specific distance and positional relationship between the camera 50 and the depth detection device 20 .

In this embodiment of the present application, the light source 211a included in the projector 21 may be a vertical-cavity surface-emitting laser (VCSEL), a laser diode (LD), or a light-emitting diode (LED). ), but not limited to this. Among them, VCSEL is increasingly used in projectors 21 due to its advantages such as small size, low power consumption, high beam quality, small divergence angle, and circularly symmetric light field distribution. Therefore, the projector in the embodiment of the present application The light source 211a included in 21 may be a VCSEL.

Each light source 211a included in the projector 21 may be of the same type. For example, each light source 211a may be a VCSEL or an LED. The types of each light source 211a included in the projector 21 may also be different. For example, some of the light sources 211a are VCSELs, some of the light sources 211a are LDs, and some of the light sources 211a are LEDs. In the embodiment of the present application, the polarization state of the light emitted by each light source 211a is the same, and the specific type of each light source 211a is not limited. In order to make the structure of the projector 21 simpler and the projected light more uniform, thereby improving the accuracy of depth information detection, each light source 211a included in the projector 21 may be of the same type.

The plurality of light sources 211a included in the projector 21 may be distributed in regular shapes such as rectangular array, circular array, linear array, regular polygonal array, elliptical array, etc., or may be distributed in an asymmetric pattern array, and the specific distribution form is not limited. Each light source 211a distributed in an array is the light source array 211.

The number of light sources 211a included in the projector 21 may be 10 to 100. For example, the number of light sources 211a included in the projector 21 is 10, 50 or 100. The projector 21 may also include other more or less. number of light sources 211a. It can be understood that the number of light sources 211a included in the projector 21 should not be too large to avoid the projector 21 having a higher structural complexity and larger volume, thereby preventing the projector 21 from occupying a larger space of the electronic device and causing the electronic device to The size is large; the number of light sources 211a included in the projector 21 should not be too small to avoid being unable to accurately obtain the depth information of the object to be measured due to insufficient projection energy and a small projection light coverage area.

The light emitted by the light source 211a may be infrared light, and the wavelength of the infrared light may be any wavelength greater than 760 nanometers, such as 800 nanometers, 940 nanometers, 1000 nanometers, etc., but is not limited thereto.

In a specific embodiment, the wavelength of the infrared light emitted by the light source 211a may be greater than 830 nanometers. For example, the wavelength of the light emitted by the light source 211a can be 840 nanometers, 900 nanometers, 940 nanometers, 980 nanometers, 1000 nanometers, etc., but is not limited thereto. Since the intensity of light greater than 830 nanometers in ambient light is relatively weak, when the wavelength of light emitted by the light source 211a is greater than 830 nanometers, it helps to reduce the interference caused by ambient light on depth detection, thereby improving the performance of the depth detection device 20 Detection accuracy.

FIG. 6 is a schematic structural diagram of the projector 21 of the electronic device shown in FIG. 3 .

In one embodiment, as shown in FIG. 6 , the above-mentioned projector 21 may further include: a light uniforming device 212 provided on the light exit side of the light source 211a. Among them, the uniform light device 212 is used to adjust the energy distribution of the light beam emitted by the light source 211a to obtain a uniform light beam. Through the uniform light processing, the optical power of the light beam emitted by the light source 211a can be made more uniform, which can prevent the local optical power from being too small, thereby preventing the final depth map of the object from having blind spots.

Optionally, the above-mentioned uniform light device 212 may be a diffractive optical element.

The function of the above-mentioned diffractive optical elements (DOE) is to shape the light beam emitted by the light source array 211 into more uniform light. Specifically, DOE can be used to shape the light beam emitted by the light source array 211 into a uniform square light source 211a or a uniform rectangular light source 211a with a certain viewing angle FOV (for example, a 5°×5° FOV).

In this embodiment, diffractive optical elements can be used to make the light projected by the projector 21 more uniform, thereby making the depth detection more accurate. And because the optical diffraction element can shape the light beam into a uniform shape with a certain viewing angle field, the light projected by the projector 21 can be more accurately aimed at the object to be detected.

Optionally, the above-mentioned light uniforming device 212 may also be a microlens array.

The above-mentioned microlens array can be a microlens diffuser. The microlens array can achieve uniform light based on geometric optics, and its transmission efficiency can reach more than 80%. It is composed of a series of microlenses distributed in an array. The microlens array is used for Shaping the light emitted by the light source array 211 makes the shaped light beam more uniform, thereby making the light projected by the projector 21 more uniform and making the depth detection more accurate.

Each microlens in the microlens array can be distributed in a regular array. For example, each microlens can be distributed in a rectangular, circular, regular polygon, or linear array, and the distance between every two adjacent microlenses is equal. Alternatively, each microlens in the microlens array may be distributed in an irregular array. For example, each microlens may be distributed in an asymmetric pattern array, and the distance between every two adjacent microlenses is not exactly equal. This application does not limit the specific distribution mode of the microlens array.

The homogenizing device 212 can also be other devices that can make the light beam more uniform, and the specific structure of the homogenizing device is not limited.

FIG. 7 is a schematic structural diagram of the receiver 22 of the electronic device shown in FIG. 3 .

In one embodiment, as shown in FIG. 7 , the above-mentioned receiver 22 may include a condensing lens 221 and a photoelectric sensor 222 located on the light exit side of the condensing lens 221 . The light exit side of the condensing lens 221 is the side of the condensing lens 221 facing away from the circular polarizer 11 .

The above-mentioned converging lens 221 may include one, or may include multiple stacked arrangements. The converging lens 221 has a converging effect on light. The converging lens 221 is used to converge the reflected light of the light emitted outwardly by the projector 21, thereby making the reflected light More depth information can be received by the photoelectric sensor 222 of the receiver 22 to detect more depth information of the object to be detected, making the depth detection more accurate.

The above-mentioned photoelectric sensor 222 is used to convert the received optical signal into an electrical signal, so as to calculate the depth information of the object to be measured based on the converted electrical signal.

The processor may be electrically connected to the photoelectric sensor 222 to calculate the depth information of the object to be measured based on the electrical signal converted by the photoelectric sensor 222 .

In one embodiment, as shown in Figure 7, the above-mentioned receiver 22 may also include a filter 223. The filter 223 is provided between the condensing lens 221 and the photoelectric sensor 222 for filtering the incident light and removing infrared light. light outside. This filter 223 may also be called an infrared filter 223.

Since the light emitted by the light source 211a of the projector 21 is usually infrared light, this embodiment uses the filter 223 to filter out the light other than infrared light in the ambient light, which can reduce the interference caused by the ambient light on the depth detection, thereby enabling The detection accuracy of the depth detection device 20 is improved.

In the embodiment of the present application, the same polarization state of the light emitted by each light source 211a means that the light emitted by each light source 211a has the same polarization type and the same polarization direction.

The types of light emitted by the light source 211a generally include: linearly polarized light, circularly polarized light, and elliptically polarized light. Among them, the trajectory of the endpoint of the light vector of linearly polarized light is a straight line, that is, the light vector only vibrates along a certain direction. The trajectory of the light vector endpoint of elliptically polarized light is an ellipse, that is, the light vector continuously rotates, and the size and direction of the light vector change regularly with time. The trajectory of the endpoint of the light vector of circularly polarized light is a circle, that is, the light vector continuously rotates, its size remains unchanged, but its direction changes regularly with time.

Among them, linearly polarized light and circularly polarized light can also be understood as special forms of elliptically polarized light. When the amplitude of the short axis of vibration of elliptically polarized light is 0, it is linearly polarized light. When the amplitude of the long axis of vibration of elliptically polarized light is the same as the short axis of vibration, When the axial amplitudes are equal, it is circularly polarized light.

FIG. 9 is a schematic diagram of the light beams emitted by each light source 211a in the electronic device shown in FIG. 3 passing through the circular polarizer 11. FIG. 10 is a schematic diagram of the light beams emitted by each light source 211a passing through the circular polarizer 11 in another example of the electronic device provided by the embodiment of the present application. FIG. 11 is a schematic diagram of the light beams emitted by each light source 211a passing through the circular polarizer 11 in another example of the electronic device provided by the embodiment of the present application. FIG. 12 is a schematic structural diagram of the light source array 211 in the electronic device shown in FIG. 3 . FIG. 13 is a schematic structural diagram of a light source array 211 of another example of an electronic device provided by an embodiment of the present application. FIG. 14 is a schematic structural diagram of a light source array 211 of another example of the electronic device provided by the embodiment of the present application. FIG. 15 is a schematic structural diagram of a light source array 211 of another example of the electronic device provided by the embodiment of the present application. FIG. 16 is a schematic structural diagram of a light source array 211 of another example of the electronic device provided by the embodiment of the present application. FIG. 17 is a schematic structural diagram of a light source array 211 of another example of the electronic device provided by the embodiment of the present application.

As shown in Figures 11, 16, and 17, the light emitted by each light source 211a of the light source array 211 can be linearly polarized light with the same polarization direction; or, as shown in Figures 9, 12, and 13, the light source array 211 can emit linearly polarized light with the same polarization direction. The light emitted by each light source 211a of the light source array 211 can all be circularly polarized light with the same polarization direction; or, as shown in Figures 10, 14, and 15, the light emitted by each light source 211a of the light source array 211 can all be circularly polarized light with the same polarization direction. The same elliptically polarized light. The transmission axis of the linear polarizer in Figures 10 and 11 is in the horizontal direction, and oblique linearly polarized light, that is, linearly polarized light, is neither parallel to the horizontal transmission axis nor perpendicular to the horizontal transmission axis.

As shown in Figures 12, 14, and 16, the amplitudes of the light emitted by each light source 211a may be the same; or, as shown in Figures 13, 15, and 17, the amplitudes of the light emitted by each light source 211a may also be different. . When the amplitude of the light emitted by each light source 211a is the same, the light emitted by the projector 21 can be more uniform, so that the depth of the object to be measured can be detected more accurately, and the structure of the projector 21 can also be simpler and more compact.

Linearly polarized light with the same polarization direction means that the vibration directions of each linearly polarized light are parallel. The amplitudes of linearly polarized lights with parallel vibration directions may be equal, and the amplitudes of linearly polarized lights with parallel vibration directions may also be unequal. As shown in Figures 11 and 16, the light emitted by each light source 211a is linearly polarized light with parallel polarization directions and the same amplitude; as shown in Figure 17, the light emitted by each light source 211a has the same polarization direction but different amplitudes. linearly polarized light.

In the embodiment of the present application, the polarization direction of the polarized light is the vibration direction.

Elliptically polarized light with the same polarization direction means that each elliptically polarized light has the same rotation direction and the long axis of vibration is parallel. Wherein, the vibration long-axis amplitude values of each elliptically polarized light may be the same or different, and the vibration short-axis amplitude values of each elliptically polarized light may be the same or different. Each elliptically polarized light has the same rotation direction, and each elliptically polarized light may be left-handed elliptically polarized light, or each elliptically polarized light may be right-handed elliptically polarized light.

As shown in Figures 10 and 14, the light emitted by each light source 211a can all be left-handed elliptically polarized light, and the vibration long axes of each left-handed elliptically polarized light emitted are parallel, and the vibration long axis amplitude of each left-handed elliptically polarized light is The same, the amplitude value of the short axis of vibration is the same. As shown in Figure 15, the light emitted by each light source 211a may also be right-handed elliptically polarized light, with the long axis of vibration parallel, and the amplitude of the long axis of vibration and the amplitude of the short axis of vibration not exactly the same.

Circularly polarized light with the same polarization direction means that each circularly polarized light has the same rotation direction. Specifically, each circularly polarized light may be all left-handed circularly polarized light, or all may be right-handed circularly polarized light. The amplitude values of each circularly polarized light may be the same or different. For example, as shown in Figures 9 and 12, the light emitted by each light source 211a can be left-handed circularly polarized light with the same amplitude. As shown in Figure 13, the light emitted by each light source 211a can also be light with different amplitudes. Right-hand circularly polarized light.

In the embodiment of the present application, when viewed in the direction of light, the light whose electric vector rotates clockwise is called right-handed polarized light, and the light whose electric vector rotates counterclockwise is called left-handed polarized light.

The long axis of vibration of polarized light refers to the axis with the largest amplitude among the vibration directions of polarized light. For linearly polarized light, since its vibration direction is always along the same straight line, the vibration long axis direction of the linearly polarized light is the polarization direction of the linearly polarized light. For elliptically polarized light, its vibration amplitude in each direction undergoes elliptical transformation, and the vibration direction with the largest amplitude is the direction of its long axis of vibration. For circularly polarized light, since the amplitudes of each polarization direction of circularly polarized light are equal, any diameter direction of circularly polarized light is the vibration major axis direction of circularly polarized light.

From the above analysis, it can be known that the loss of the light emitted by the light source 211a when passing through the circular polarizer 11 is caused by the absorption by the linear polarizer 11b in the circular polarizer 11. Therefore, in order to reduce the loss of the light emitted by the light source 211a, the proportion of the light emitted by the light source 211a and transmitted through the 1/4 wave plate 11a that passes through the linear polarizer 11b should be increased.

The following describes the different types of polarized light emitted by the light source 211a. When the long axis of the polarized light is parallel to the optical axis of the 1/4 wave plate 11a, the light after passing through the 1/4 wave plate 11a is emitted from the linear polarizer 11b. Proportion.

It can be seen from relevant calculations that for various types of polarized light, when the long axis of vibration of the polarized light is parallel to the optical axis of the 1/4 wave plate 11a, the emitted light after the polarized light passes through the 1/4 wave plate 11a is linearly polarized light. .

First, for the case where the light emitted by the light source 211a is circularly polarized light, the emission ratio is calculated and explained. The emission ratio refers to the ratio of the intensity of the emitted light after passing through the linear polarizer 11b in the circular polarizer 11 to the intensity of the incident light when it enters the linear polarizer 11b.

The circularly polarized light emitted by the light source 211a can be converted into linearly polarized light after passing through the 1/4 wave plate 11a. The angle between the polarization direction of the converted linearly polarized light and the optical axis of the 1/4 wave plate 11a is 45°. Since the angle between the optical axis of the quarter-wave plate 11a of the circular polarizer 11 and the transmission axis of the linear polarizer 11b is also 45°, the circularly polarized light emitted by the light source 211a passes through the quarter-wave plate. The linearly polarized light converted after passing through the 1/4 wave plate 11a can be parallel to the transmission axis of the linearly polarizing plate 11b, so that the linearly polarized light converted after passing through the 1/4 wave plate 11a can completely pass through the linearly polarizing plate 11b and be emitted. The ratio is 100%.

FIG. 18 is a schematic diagram of the relationship between the optical axis of the quarter wave plate 11a and the coordinate axis of the left-handed circularly polarized light. FIG. 19 is a schematic diagram of the polarized light emitted when θ is 0° in FIG. 18 . Figure 20 is a schematic diagram of the emitted linearly polarized light when θ is 0° in Figure 18 and the incident light is right-handed circularly polarized light. Fig. 21 is a schematic diagram of the emitted polarized light when θ is 45° in Fig. 18. Figure 22 is a schematic diagram of the emitted linearly polarized light when θ is 45° in Figure 18 and the incident light is right-handed circularly polarized light.

The x and y coordinate systems in Figure 18 are the coordinate systems corresponding to circularly polarized light. Next, the Jones matrix is used to calculate the polarization state of circularly polarized light after passing through the quarter wave plate 11a.

As shown in Figure 18, taking the light incident on the quarter wave plate 11a as left-handed circularly polarized light as an example, the Jones matrix of the light vector can be expressed as:

In formula (1), A and B represent the components of left-handed circularly polarized light on the x-axis and y-axis respectively, and i represents an imaginary number.

As shown in Figure 18, assuming that the fast axis of the 1/4 wave plate 11a and the horizontal x-axis form an angle θ, and the y-axis is the vertical axis, the phase difference generated by the light passing through the 1/4 wave plate 11a is The components of the incident circularly polarized light on the fast axis and slow axis of the quarter wave plate 11a can be expressed as:

When the incident circularly polarized light emerges from the 1/4 wave plate 11a, it is necessary to consider the relative phase delay of the components on the fast axis and slow axis of the 1/4 wave plate 11a, so after considering the relative delay, A _ξ and B _eta become A respectively. ' _ξ =A _ξ , B' _η =B _η e ^iδ , that is:

The two components A' _ξ and B' _η are projected on the x-axis and y-axis respectively, and the two components of the Jones vector of the emitted light on the x-axis and y-axis are obtained, which can be expressed as:

Right now:

The Jones matrix of the quarter wave plate 11a after sorting can be expressed as:

For 1/4 wave plate 11a, Bringing in the Jones matrix of 1/4 wave plate 11a, we can get:

When θ is 0°, substitute into formula (7) to get:

Formula (5) can also be expressed as:

Put formula (8) into formula (9) to get:

Since matrix Represents a linearly polarized light at an angle of -45° with the x-axis, that is/> Represents a linearly polarized light at an angle of -45° with the fast axis of the quarter wave plate 11a. Therefore, as shown in Figure 19, when θ is 0° and the incident light is left-handed circularly polarized light, the outgoing light after passing through the 1/4 wave plate 11a is at -45° with the fast axis of the 1/4 wave plate 11a. Angular linearly polarized light.

In the embodiment of the present application, the angle between the linearly polarized light and the fast axis of the quarter wave plate 11a is less than 90 degrees formed by the rotation of the linearly polarized light relative to the fast axis of the quarter wave plate 11a, where, Clockwise rotation of linearly polarized light relative to the fast axis is positive, and counterclockwise rotation is negative.

As shown in the figure, when θ is 0° and the incident light is right-handed circularly polarized light, the emitted light after passing through the 1/4 wave plate 11a is linearly polarized light at an angle of 45° with the x-axis, that is, the emitted line The angle between the polarized light and the fast axis of the quarter wave plate 11a is 45°. The specific calculation process refers to left-handed circularly polarized light and will not be described in detail here.

If θ is 45° and the incident light is left-handed polarized light, substitute it into formula (7) to get:

Substituting formula (11) into formula (9) can be calculated:

Since matrix Represents a linearly polarized light along the y-axis, that is/> represents a linearly polarized light at an angle of -45° with the fast axis of the 1/4 wave plate 11a. The specific calculation process refers to left-handed circularly polarized light, which will not be described in detail here.

Therefore, as shown in Figure 21, if θ is 45° and the incident light is left-handed circularly polarized light, the emitted light after passing through the 1/4 wave plate 11a is linearly polarized light along the y-axis, that is, the emitted linearly polarized light is the same as 1 The fast axis of /4 wave plate 11a is at an angle of -45°.

As shown in Figure 22, if θ is 45° and the incident light is right-handed circularly polarized light, the emitted light after passing through the 1/4 wave plate 11a is linearly polarized light along the x-axis, that is, the emitted linearly polarized light is the same as 1/ The fast axis of the 4-wave plate 11a is at an included angle of 45°. The specific calculation process refers to left-handed circularly polarized light and will not be described in detail here.

It can be seen through calculation that when θ takes an angle other than 0° and 45°, if the incident light is left-handed circularly polarized light, the emergent light after passing through the 1/4 wave plate 11a is -45° from the fast axis of the 1/4 wave plate 11a For linearly polarized light with an angle of 45°, if the incident light is right-handed circularly polarized light, the emitted light after passing through the 1/4 wave plate 11a will be linearly polarized light with an angle of 45° with the fast axis of the 1/4 wave plate 11a. The calculation process of θ taking different angles can refer to the above calculation process and will not be repeated here.

In summary, it can be seen that the linearly polarized light formed after the left-handed circularly polarized light passes through the 1/4-wave plate 11a forms an angle of -45° with the fast axis of the 1/4-wave plate 11a. After the right-handed circularly polarized light passes through the 1/4-wave plate 11a The formed linearly polarized light forms an angle of 45° with the fast axis of the quarter wave plate 11a. That is to say, when the circularly polarized light passes through the 1/4 wave plate 11a, it can generate linearly polarized light at an angle of ±45° with the fast axis of the 1/4 wave plate 11a, that is, it can generate light with the 1/4 wave plate 11a. Linearly polarized light whose axes are at an angle of 45°.

The angle between the optical axis of the 1/4 wave plate 11a of the circular polarizer 11 and the transmission axis of the linear polarizer 11b is 45°. Therefore, the relative transmission axis of the linear polarizer 11b can be adjusted by adjusting the circular polarizer 11. Depending on the positive or negative angle of the 1/4 wave plate 11a (it does not destroy the characteristics of the circular polarizer 11 itself that the optical axis of the 1/4 wave plate 11a and the transmission axis of the linear polarizer form an included angle of 45°), or by Adjust the rotation direction of the circularly polarized light emitted by the light source 211a, so that the polarization direction of the linearly polarized light emitted after the circularly polarized light emitted by the light source 211a is modulated by the 1/4 wave plate 11a is parallel to the transmission axis of the linear polarizer 11b, That is to say, emission without loss of light energy can be achieved, that is, the emission ratio is 100%.

FIG. 23 is a diagram showing the correspondence between the rotation direction of the circularly polarized light emitted by the light source 211a in the electronic device shown in FIG. 3 and the optical axis of the quarter wave plate 11a. FIG. 24 is a diagram of the correspondence between the rotation direction of the circularly polarized light emitted by the light source 211a and the optical axis of the quarter wave plate 11a in another example of the electronic device provided by the embodiment of the present application.

Specifically, as shown in Figure 24, when the transmission axis of the linear polarizer 11b is rotated 45° clockwise relative to the fast axis of the 1/4 wave plate 11a, that is, the transmission axis of the linear polarizer 11b is rotated 45° clockwise relative to the fast axis of the 1/4 wave plate 11a. When the fast axis of the wave plate 11a rotates through an angle of 45°, the light emitted by the light source 211a is right-handed circularly polarized light. As shown in Figure 23, when the transmission axis of the linear polarizer 11b is rotated 45° counterclockwise relative to the fast axis of the 1/4 wave plate 11a, that is, the transmission axis of the linear polarizer 11b is rotated 45° counterclockwise relative to the fast axis of the 1/4 wave plate 11a. When the fast axis rotates through an angle of -45°, the light emitted by the light source 211a is left-handed circularly polarized light. According to this corresponding relationship, the emission ratio of the circularly polarized light emitted by the light source 211a can reach 100% after passing through the circular polarizer 11, and the light can be emitted without loss after passing through the circular polarizer 11, thus making the light source array 211 The emitted light will not be attenuated by the circular polarizer 11, which increases the intensity of the optical signal received by the receiver 22, making the depth information determined by the depth detection device 20 more accurate.

The calculation and explanation of the emission ratio will be described below for the case where the light emitted by the light source 211a is elliptically polarized light.

It can be seen from relevant calculations that when the light emitted by the light source 211a is elliptically polarized light, and the long axis of vibration of the elliptically polarized light is parallel to the optical axis (fast axis or slow axis) of the quarter wave plate 11a, after passing through the quarter wave The emitted light behind the plate 11a is linearly polarized light. Specifically, it can be calculated through the Jones matrix, and the specific calculation process will not be repeated here.

Figure 25 is a diagram showing the angular relationship between the linearly polarized light emitted after right-handed elliptically polarized light passes through the 1/4 wave plate 11a and the optical axis of the 1/4 wave plate 11a. Figure 26 shows the left-handed elliptical polarized light passing through the 1/4 wave plate. The angular relationship between the linearly polarized light emitted after 11a and the optical axis of the 1/4 wave plate 11a. In Figures 25 and 26, the long axis of vibration of the elliptically polarized light is parallel to the fast axis of the 1/4 wave plate 11a.

As shown in Figure 25, the angle between the linearly polarized light emitted after the right-handed elliptical polarized light passes through the 1/4 wave plate 11a and the slow axis of the 1/4 wave plate 11a is θ = arctan (a/b), where, a and b are respectively the long-axis amplitude value and the short-axis amplitude value of the right-handed elliptically polarized light emitted by the light source 211a. Since the values of a and b of the ellipse are not equal, the degree of θ is not equal to 45°, and the angle between the transmission axis of the linear polarizer 11b and the optical axis of the quarter wave plate 11a is 45°, so, The vibration direction of the linearly polarized light emitted after the right-handed elliptically polarized light passes through the quarter wave plate 11a is not parallel to the transmission axis of the linearly polarized plate 11b.

When the transmission axis of the linear polarizing plate 11b is in the horizontal direction as shown in Figure 25, that is, the linearly polarized light emitted after the transmission axis passes through the 1/4 wave plate 11a is oblique linearly polarized light, and some of the oblique linearly polarized light will be The component cannot be emitted through the linear polarizer 11b, and the light intensity of the oblique linearly polarized light emitted through the linear polarizer 11b can be expressed as The emission ratio is cos(θ-π/4), and the value of the emission ratio is specifically related to θ, that is, to the ratio of the long-axis amplitude value and the short-axis amplitude value of the left-handed elliptically polarized light emitted by the light source 211a.

The value range of θ is (π/4, π/2), and cos(θ-π/4) is a decreasing function in the range of (π/4, π/2). When θ=π/4, the emission ratio is the largest is 1. When θ=π/2, the minimum emission ratio is 0.707, so the average emission ratio is about 0.85, that is, about 85%. It can be seen that when the vibration long axis of the right-handed elliptically polarized light emitted by the light source 211a is parallel to the fast axis of the 1/4 wave plate 11a, and the transmission axis of the linear polarizer 11b is relative to the fast axis of the 1/4 wave plate 11a, When the included angle is 45°, the output ratio of the linearly polarized light generated by the right-handed elliptically polarized light passing through the 1/4 wave plate 11a passing through the linear polarizing plate 11b is about 85% on average.

As shown in Figure 26, when the vibration long axis of the left-handed elliptically polarized light emitted by the light source 211a is parallel to the fast axis of the 1/4 wave plate 11a, and the transmission axis of the linear polarizer 11b is relative to the fast axis of the 1/4 wave plate 11a, When the angle between the axes is -45°, the output ratio of the linearly polarized light generated by the left-handed elliptically polarized light passing through the 1/4 wave plate 11a passing through the linear polarizing plate 11b is about 85% on average. The specific calculation process can refer to the right-handed polarized light in Figure 25, and will not be described again here.

The emission ratio when the long axis of vibration of elliptical polarized light is parallel to the slow axis of the 1/4 wave plate 11a is the same as the emission ratio when it is parallel to the fast axis of the 1/4 wave plate 11a. The calculation method can be referred to when it is parallel to the fast axis. The relevant calculations will not be repeated here.

It can be seen from the above analysis that when the long axis of vibration of the elliptically polarized light is parallel to the optical axis of the 1/4 wave plate 11a of the circular polarizer 11, the elliptically polarized light can form linearly polarized light through the 1/4 wave plate 11a, and the lines formed After the polarized light passes through the linear polarizer 11b of the circular polarizer 11, the exit ratio is about 85%, which is a relatively high exit ratio.

Specifically, when the long axis of vibration of the elliptically polarized light is parallel to the optical axis of the 1/4 wave plate 11a of the circular polarizer 11, if the transmission axis of the linear polarizer 11b is along the axis relative to the fast axis of the 1/4 wave plate 11a Rotate 45° clockwise, that is, when the transmission axis of the linear polarizer 11b rotates 45° relative to the fast axis of the quarter wave plate 11a, the light emitted by the light source 211a is right-handed elliptically polarized light; if The transmission axis of the polarizer 11b is rotated 45° counterclockwise relative to the fast axis of the 1/4 wave plate 11a. That is, the angle at which the transmission axis of the linear polarizer 11b is rotated relative to the fast axis of the 1/4 wave plate 11a is At -45°, the light emitted by the light source 211a is left-handed elliptically polarized light. Setting according to this corresponding relationship can make the elliptically polarized light emitted by the light source 211a reach about 85% after passing through the circular polarizer 11, which significantly increases the amount and the exit ratio of the light after passing through the circular polarizer 11, thus improving the efficiency of the light source. The intensity of the optical signal received by the receiver 22 makes the depth information determined by the depth detection device 20 more accurate.

It can be seen that for circularly polarized light and elliptically polarized light, the amount of light and the emission ratio after passing through the circular polarizer 11 can be significantly improved by setting it in the following way: when the transmission axis of the linear polarizer 11b is faster than the 1/4 wave plate 11a When the axis rotates 45° clockwise, the light emitted by the light source 211a is right-handed polarized light; when the transmission axis of the linear polarizer 11b rotates 45° counterclockwise relative to the fast axis of the 1/4 wave plate 11a, the light source 211a The light emitted by 211a is left-handed polarized light.

The calculation and explanation of the emission ratio will be given below for the case where the light emitted by the light source 211a is linearly polarized light.

When the linearly polarized light emitted by the light source 211a is parallel to the optical axis of the 1/4-wave plate 11a, the linearly polarized light will remain linearly polarized light with unchanged vibration direction after passing through the 1/4-wave plate 11a. Since the circular polarizer 11 The angle between the optical axes of the linear polarizer 11b and the 1/4 wave plate 11a is 45°, so the component ratio of the linearly polarized light on the transmission axis of the linear polarizer 11b is That is 71%, so the emission ratio is approximately 71%.

It can be seen that when the light emitted by the light source 211a is linearly polarized light, and the polarization direction of the emitted linearly polarized light is parallel to the optical axis of the 1/4 wave plate 11a, the light intensity after passing through the circular polarizer 11 can also be significantly improved. The amount of light and the emission ratio are thereby increased, thereby increasing the intensity of the light signal received by the receiver 22, making the depth information determined by the depth detection device 20 more accurate.

It can be seen from the above analysis that when the long axis of vibration of the polarized light emitted by the light source 211a is parallel to the optical axis of the quarter wave plate 11a, and the polarization state of the light emitted by each light source 211a of the projector 21 is the same, The emission ratio can be greatly improved. When the light source 211a emits linearly polarized light, the emission ratio can be increased to about 71%. When the light source 211a emits elliptically polarized light, the emission ratio can be increased to 85%. About %, when the light source 211a emits circularly polarized light, the emission ratio can be increased to 100%. In this way, the emission light after the light emitted by the projector 21 of the depth detection device 20 passes through the circular polarizer 11 is greatly reduced. The attenuation rate makes the projector 21 have a higher ability to emit light in the external environment, and the light signal received by the receiver 22 is lighter, so that the depth information determined by the depth detection device 20 is more accurate.

In the electronic device provided by the embodiment of the present application, since the polarization states of the light emitted by each light source 211a of the projector 21 are the same, and the long axis of vibration of the polarized light emitted by the light source 211a is parallel to the optical axis of the quarter wave plate 11a, Therefore, the light emitted by each light source 211a can form linearly polarized light after passing through the 1/4 wave plate 11a of the circular polarizer 11, and the formed linearly polarized light is more likely to pass through the linear polarizer 11b of the circular polarizer 11 at a larger proportion. , so that the attenuation of the emitted light from the light source 211a after passing through the circular polarizer 11 is smaller, so that the signal of the reflected light received by the receiver 22 is stronger, so that the depth information determined by the depth detection device 20 is more accurate.

The embodiment of the present application also provides a depth detection device for installation in the housing 70 of an electronic device. The depth detection device includes a projector and a receiver 22 .

The projector is used to emit light through the circular polarizer 11 of the electronic device. The projector includes a plurality of light sources 211a distributed in an array. The light emitted by each light source 211a is polarized light with the same polarization state. When the depth detection device is installed on the housing When inside the body 70, the long axis of vibration of the polarized light is parallel to the optical axis direction of the 1/4 wave plate 11a of the circular polarizer 11; the receiver 22 is used to receive the reflected light of the light emitted outwardly by the projector.

In one embodiment, the light source 211a may be any one of a vertical cavity surface emitting laser, a laser diode, and a light emitting diode, but is not limited thereto.

In one embodiment, the above-mentioned projector may further include: a light uniformity device 212 provided on the light exit side of the light source 211a.

In one implementation, the uniform light device 212 may be a diffractive optical element or a microlens array.

In one implementation, the light emitted by the light source 211a may be infrared light, and the wavelength of the infrared light is greater than 830 nanometers.

In one implementation, the receiver 22 may include a condensing lens 221 and a photosensor 222 located on the light exit side of the condensing lens 221 .

In one embodiment, the receiver 22 may further include: a filter 223 disposed between the condensing lens 221 and the photoelectric sensor 222. The filter 223 is used to filter light other than infrared light in the incident light.

Since the depth detection device has the same structure as the depth detection device included in the above-mentioned electronic equipment, the technical effects brought by the depth detection device to the electronic equipment are the same as those of the above-mentioned electronic equipment, and will not be described again here.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, and all of them should be covered. within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims (8)

1. An electronic device, comprising:

a housing (70);

the display screen (10) is covered on the shell (70), the display screen (10) comprises a display module (12) and a circular polarizer (11) arranged on the display side of the display module (12), and the circular polarizer (11) comprises a 1/4 wave plate (11 a) and a linear polarizer (11 b) which are sequentially arranged from the inner side to the outer side of the shell (70);

The depth detection device (20) comprises a projector (21) and a receiver (22) which are arranged in the shell (70), wherein the projector (21) is used for emitting light outwards through the circular polarizer (11), the projector (21) comprises a plurality of light sources (211 a) distributed in an array, the light emitted by each light source (211 a) is polarized light with the same polarization state, the vibration long axis of the polarized light is parallel to the optical axis of the 1/4 wave plate (11 a), and the receiver (22) is used for receiving the reflected light of the light emitted outwards by the projector (21);

the transmission axis of the linear polaroid (11 b) rotates 45 degrees clockwise relative to the fast axis of the 1/4 wave plate (11 a), the light emitted by the light source (211 a) is right-handed circularly polarized light, the light emitted by the light source (211 a) is infrared light, and the wavelength of the infrared light is more than 830 nanometers;

the light source (211 a) emits light of the same amplitude;

the projector (21) further includes: and the light homogenizing devices (212) are arranged on the light emitting side of the light source (211 a), the light homogenizing devices (212) are microlens arrays distributed in a regular array, and the distances between every two adjacent microlenses are equal.

2. The electronic device according to claim 1, wherein the transmission axis of the linear polarizer (11 b) is rotated by 45 ° in a counterclockwise direction with respect to the fast axis of the 1/4 wave plate (11 a), and the light emitted from the light source (211 a) is left-hand polarized light, which is left-hand elliptically polarized light or left-hand circularly polarized light.

3. The electronic device according to claim 1, wherein an angle between a transmission axis of the linear polarizer (11 b) and a fast axis of the 1/4 wave plate (11 a) is 45 °, the light emitted from the light source (211 a) is linearly polarized light, and a vibration direction of the linearly polarized light is parallel to an optical axis of the 1/4 wave plate (11 a).

4. The electronic device of any one of claims 1-3, wherein the electronic device further comprises:

the display module (12), the circular polarizer (11) and the glass cover plate (13) are sequentially stacked and arranged on the shell (70).

5. The electronic device of any of claims 4, wherein the electronic device further comprises:

the camera (50) is arranged in the shell (70) and faces the glass cover plate (13), through holes for the camera (50) to receive external light rays are formed in the display module (12) and the circular polarizer (11), and the camera (50) and the depth detection device (20) are arranged adjacently.

6. The electronic device according to any one of claims 1 to 5, wherein the light source (211 a) is any one of a vertical cavity surface emitting laser, a laser diode, a light emitting diode.

7. The electronic device according to claim 1, characterized in that the receiver (22) comprises a converging lens (221) and a photosensor (222) located at the light exit side of the converging lens (221).

8. The electronic device of claim 7, wherein the receiver (22) further comprises:

and a filter (223) provided between the converging lens (221) and the photosensor (222) for filtering light other than infrared light among the incident light.