CN108227205A - One kind wears display optical system and wears display equipment - Google Patents

Abstract

The invention belongs to the technical field of smart wearable electronic devices, and provides a head-mounted display optical system and a head-mounted display device. The head-mounted display optical system includes an image generation unit, a first lens unit, a first optical unit and The second optical unit, wherein the image generation unit is used to generate the light beam, the first lens unit is used to transmit the light beam and adjust the propagation direction of the light beam, the first optical unit is used to reflect and transmit the light beam, and the second optical unit is used for Reflecting the light beam, the light beam reflected by the second optical unit returns to the first optical unit, and enters the user's eyes after being transmitted by the first optical unit; it also includes a light blocking device for blocking ambient stray light from reaching the first optical unit, The light blocking device is arranged on the side of the first optical unit facing away from the first lens unit; the light blocking device is provided to prevent ambient stray light from affecting the light beam in the head-mounted display optical system, improve imaging quality, and improve user experience.

Description

Head-mounted display optical system and head-mounted display device

technical field

The invention belongs to the technical field of smart wearable electronic equipment, and more specifically relates to a head-mounted display optical system and a head-mounted display device.

Background technique

With the continuous development of science and technology, more and more display devices are widely used in people's daily life and work, bringing great convenience to people's daily life and work, and becoming an indispensable tool for people today. . Among them, head-mounted display technology, as a new technology combining optics, electronics, software interaction and other fields, has also developed by leaps and bounds.

Microdisplays and optical systems in a head-mounted display (HMD) project images from the microdisplays to the user's eyes and allow the user to see the real world. Head-mounted displays have many utilitarian and recreational applications, such as aeronautics and aerospace applications that allow pilots to see important flight control information without taking their eyes off the flight path; public safety applications including tactical maps and thermal imaging display; applications in other areas include video games, transportation, and radio communications.

However, since external light is allowed to enter the head-mounted display, some stray light will also enter the optical imaging system. When the stray light enters the user's eyes, the user will see the image information carried by the stray light. However, this information is not what the user wants to see, and thus will affect the user experience.

The above deficiencies need to be improved.

Contents of the invention

The purpose of the present invention is to provide a head-mounted display optical system to solve the technical problem existing in the prior art that stray light enters into the head-mounted display device and affects the imaging quality.

In order to achieve the above purpose, the technical solution adopted by the present invention is to provide a head-mounted display optical system, including sequentially arranged along the optical path:

an image generating unit, configured to generate and emit light beams carrying image information;

The first lens unit is used to transmit the light beam and adjust the propagation direction of the light beam;

The first optical unit is used to reflect and transmit the light beam, and the central axis of the first optical unit forms a first preset angle with the central axis of the first lens unit;

The second optical unit is used to reflect the light beam, and the central axis of the second optical unit forms a second preset angle with the central axis of the first lens unit;

The light beam returns to the first optical unit after being reflected by the second optical unit, and enters the user's eyes after being transmitted by the first optical unit;

The head-mounted display optical system also includes:

The light blocking device is arranged on a side of the first optical unit facing away from the first lens unit, and is used to block ambient stray light from reaching the first optical unit.

Further, the light blocking device includes a fixing part for connecting the first optical unit and a light blocking part for blocking light, connecting parts are provided on opposite sides of the fixing part, and the light blocking part connected with the connecting portion;

The size of the light blocking portion is not smaller than the projected area of the first optical unit in the direction of the light blocking device.

Further, the first preset included angle is 45°, and the second preset included angle is 90°;

The image generating unit is a microdisplay, and the microdisplay is coaxial with the first lens unit;

The first lens unit includes at least one lens;

The direction where the central axis of the second optical unit is located is the X direction, the direction where the central axis of the microdisplay is located is the Y direction, the X direction and the Y direction are perpendicular to each other, and the central axis of the microdisplay and the Y direction are perpendicular to each other. The central axis of the second optical unit is perpendicular to the first optical unit.

Further, the first lens unit includes a first lens and a second lens arranged in sequence along the optical path, the first lens and the second lens are coaxial and coaxial with the image generating unit;

The included angle between the central axis of the first lens and the Y direction is not greater than 3°, and the included angle between the central axis of the second lens and the Y direction is not greater than 3°;

The displacement of the first lens in the X direction does not exceed 2 millimeters, and the displacement of the first lens in the Y direction does not exceed 2 millimeters;

The displacement of the second lens in the X direction does not exceed 2 millimeters, and the displacement of the second lens in the Y direction does not exceed 2 millimeters.

Further, the first optical unit includes a first optical lens, the surface of the first optical lens facing the first lens unit is provided with a first semi-reflective and semi-permeable film, and the first optical lens faces away from the The surface of the first lens unit is provided with a first anti-reflection film;

or,

The surface of the first optical lens facing the first lens unit is provided with a first anti-reflection film, and the surface of the first optical lens facing away from the first lens unit is provided with a first semi-reflective and semi-permeable film.

Further, the included angle between the central axis of the first optical lens and the Y direction is not greater than 5°;

The first optical lens is a non-planar mirror, the displacement of the first optical lens in the X direction is not more than 1 millimeter, and the displacement of the first optical lens in the Y direction is not more than 1 millimeter.

Further, the second optical unit includes a second optical lens, the surface of the second optical lens facing the first optical unit is provided with a second semi-reflective and semi-permeable film, and the second optical lens faces away from the The surface of the first optical unit is provided with a second anti-reflection film;

or,

The surface of the second optical lens facing the first optical unit is provided with a second anti-reflection film, and the surface of the second optical lens facing away from the first optical unit is provided with a second semi-reflective and semi-transparent film.

Further, the central axis of the second optical lens is perpendicular to the central axis of the microdisplay, and the included angle between the central axis of the second optical lens and the Y direction is not greater than 0.5°;

The displacement of the second optical lens in the X direction is not more than 0.5 mm, and the displacement of the second optical lens 41 in the Y direction is not more than 0.5 mm.

Further, the second optical lens is an equal-thickness optical lens;

The second optical lens is a resin lens, and the surface of the second optical lens is coated with a photochromic coating;

or,

The second optical lens is a resin lens, and the surface of the second optical lens is permeated with a photochromic material;

or,

The second optical lens is a glass lens, and a photochromic material is evenly distributed in the second optical lens.

The purpose of the present invention is also to provide a head-mounted display device, including the above-mentioned head-mounted display optical system.

The beneficial effect of the head-mounted display optical system provided by the present invention is that: since the light blocking device is provided on the side of the first optical unit facing away from the first lens unit, the ambient stray light is blocked by the light blocking device It cannot reach the first optical unit, and thus cannot reach the user's eyes, avoiding the influence of ambient stray light on the light beam in the head-mounted display optical system, and ensuring the imaging quality of the head-mounted display optical system; at the same time, due to stray light cannot reach The first optical unit will not enter the user's eyes, so the user will not see the image information carried by stray light (such as the ground, clothes, pants, etc.) The image entering the user's eyes after the optical unit effectively improves the user experience.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the descriptions of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only of the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a head-mounted display optical system provided by an embodiment of the present invention;

2 is a schematic diagram of the optical path structure of the head-mounted display optical system provided by the embodiment of the present invention;

FIG. 3 is a schematic diagram of a partial structure of a head-mounted display optical system provided by an embodiment of the present invention;

FIG. 4 is a second partial structural schematic diagram of the head-mounted display optical system provided by the embodiment of the present invention;

FIG. 5 is a schematic diagram of the partial structure of the head-mounted display optical system provided by the embodiment of the present invention III;

6 is a schematic structural diagram of a light blocking device of a head-mounted display optical system provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram of the exploded structure of the light blocking device of the head-mounted display optical system provided by the embodiment of the present invention;

FIG. 8 is a schematic diagram of the coordinate axes of the head-mounted display optical system provided by the embodiment of the present invention;

9 is a schematic structural diagram of the first optical unit of the head-mounted display optical system provided by the embodiment of the present invention;

10 is a schematic structural diagram of the second optical unit of the head-mounted display optical system provided by the embodiment of the present invention;

Fig. 11 is a schematic diagram 4 of a partial structure of the head-mounted display optical system provided by the embodiment of the present invention;

Fig. 12 is a schematic diagram of a partial structure of the head-mounted display optical system provided by the embodiment of the present invention;

FIG. 13 is an MTF curve diagram of each field of view of the head-mounted display optical system provided by the embodiment of the present invention.

Wherein, each reference sign in the figure:

1-image generating unit; 2-first lens unit;

21-first lens; 22-second lens;

3-the first optical unit; 31-the first optical lens;

311-first upper surface; 312-first lower surface;

4-the second optical unit; 41-the second optical lens;

411 - the second upper surface; 412 - the second lower surface;

5-light blocking device; 51-fixed part;

510-the first accommodating part; 511-the through hole of the fixed part;

52-light blocking part; 53-connecting part;

6 - eyes.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

It should be noted that when an element is referred to as being “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

Referring to FIG. 1 and FIG. 2 , a head-mounted display optical system includes an image generating unit 1 , a first lens unit 2 , a first optical unit 3 and a second optical unit 4 sequentially arranged along an optical path. Wherein the image generation unit 1 is used to generate and emit a light beam carrying image information, the first lens unit 2 is used to transmit the light beam generated by the image generation unit 1 and adjust the propagation direction of the light beam, and the first optical unit 3 is used to adjust the light beam Reflection and transmission, the second optical unit 4 is used to reflect the light beam, the light beam reflected by the second optical unit 4 returns to the first optical unit 3, and enters the user's field of vision after being transmitted by the first optical unit 3, that is, the user's eyes6. The central axis of the first optical unit 3 forms a first preset included angle with the central axis of the first lens unit 2 , and the central axis of the second optical unit 4 forms a second preset included angle with the central axis of the first lens unit 2 . The head-mounted display optical system further includes a light blocking device 5 for blocking ambient stray light from reaching the first optical unit 3 , and the light blocking device 5 is arranged on a side of the first optical unit 3 facing away from the first lens unit 2 .

The working principle of the head-mounted display optical system provided in this embodiment is as follows: the image generation unit 1 generates a light beam carrying image information, and sends the light beam to the first lens unit 2; after the first lens unit 2 adjusts the propagation direction of the light beam , the light beam is transmitted to the first optical unit 3; after the light beam reaches the first optical unit 3, part of the light beam is reflected, and part of it is transmitted, and the reflected light beam reaches the second optical unit 4; the second optical unit 4 reflects the light beam, and passes through the second optical unit 4 The light beam reflected by the second optical unit 4 returns to the first optical unit 3; after the light beam reaches the first optical unit 3, part of it is reflected and part of it is transmitted, and the transmitted light beam reaches the user's eye 6, so that the user's eye 6 can obtain an image Image information for unit 1 is generated. The ambient stray light located on the side of the first optical unit 3 opposite to the first lens unit 2 cannot enter the head-mounted display optical system under the blocking of the light blocking device 5 , so that it cannot reach the first optical unit 3 , Furthermore, it cannot reach the user's eyes 6 , ensuring that only the light beam passing through the second optical unit 4 can reach the user's eyes 6 .

The beneficial effect of such setting is: since the light blocking device 5 is provided on the side of the first optical unit 3 facing away from the first lens unit 2, the ambient stray light cannot reach the first optical lens under the blocking of the light blocking device 5. Unit 3, and thus cannot reach the user's eyes 6, avoiding the influence of ambient stray light on the light beam in the head-mounted display optical system, ensuring the imaging quality of the head-mounted display optical system; at the same time, due to the stray light cannot reach the first optical Unit 3, so that it will not enter the user's eyes 6, so the user will not see the image information (such as the ground, clothes, pants, etc.) carried by stray light during use, but can only see the image information passing through the first optical The image entering the user's eyes 6 behind the unit 3 effectively improves the user experience.

Further, the size of the light blocking device 5 is not smaller than the projected area of the first optical unit 3 in the direction of the light blocking device 5, so as to avoid that the size of the light blocking device 5 cannot completely block ambient stray light, thereby ensuring that the light blocking device 5. It can completely block ambient stray light, which is beneficial to improving the imaging quality of the head-mounted display optical system, thereby improving user experience.

Please refer to Fig. 3 to Fig. 5, further, the specific position of the light blocking device 5 can be set according to needs, for example, the light blocking device 5 can be perpendicular to the central axis of the image generating unit 1, also can not be vertical, as long as the light blocking device The size of 5 is not smaller than the projected area of the first optical unit 3 in the direction of the light blocking device 5, so that the light blocking device 5 can block ambient stray light and prevent ambient stray light from entering the first optical unit 3.

Please refer to FIG. 6 and FIG. 7 , further, the light blocking device 5 includes a fixing part 51 for connecting the first optical unit 3 and a light blocking part 52 for blocking light, and the opposite sides of the fixing part 51 are provided with connecting parts. Section 53.

In this embodiment, the two connecting parts 53 are isosceles triangle connecting plates, the bottom edge of the isosceles triangle connecting plates is connected to the lower end of the fixed part 51, and the isosceles triangle connecting plates are provided with a light shielding part 52 connected The connecting shaft; the light blocking part 52 is a U-shaped plate, and the two ends of the U-shaped plate are provided with connecting holes connected with the connecting shaft, and the connecting holes are matched with the connecting shaft. It should be understood that the connecting portion 53 can also be in other shapes, and is not limited to the above-mentioned situation; It only needs that the light blocking portion 52 can effectively block ambient stray light.

Preferably, the light blocking part 52 is connected with the connecting part 52 and can rotate relative to the connecting part 53 . In actual use, since the incident angle of stray light in the environment will change with different environments, since the light blocking part 52 can rotate relative to the connecting part 53, that is, the light blocking part 52 can rotate relative to the fixed part 51, so that the light blocking part The relative position of 52 and the first optical unit 3 can be adjusted as required, so as to ensure that the light blocking part 52 can effectively block ambient stray light. It should be understood that the light blocking portion 52 can also be fixed relative to the connecting portion 53 (that is, the light blocking portion 52 and the connecting portion 53 do not rotate relative to each other), as long as the light blocking portion 52 can effectively block ambient stray light.

In one embodiment, the upper surface of the fixing part 51 (the side opposite to the light blocking part 52) is also provided with a first accommodating part 510 for accommodating the image generating unit 1, and the size of the first accommodating part 510 and the image The size of the generating unit 1 is adapted, so that it can well limit the image generating unit 1 and prevent the image generating unit 1 from shaking randomly during use, which will affect the image quality. The fixed portion 51 also has a fixed portion through hole 511, the first lens unit 2 is accommodated in the fixed through hole 511, the first optical unit 3 is accommodated in the U-shaped area of the light blocking portion 52 and is connected to the first lens unit 2. The positions are adapted; the position of the light blocking part 52 relative to the first optical unit 3 is adjusted to ensure that the light blocking part 52 can effectively block ambient stray light.

Further, the size of the light blocking portion 52 is adapted to the projected area of the first optical unit 3 in the direction of the light blocking portion 52 . Preferably, the size of the light blocking portion 52 is the same as the projected area of the first optical unit 3 in the direction of the light blocking portion 52 , so that the size of the light blocking portion 52 can be reduced, thereby reducing the overall volume of the head-mounted display optical system.

Preferably, the surface of the light blocking device 5 is black or dark, so as to better absorb the stray light irradiated on the surface of the light blocking device 5 and improve the blocking effect of the light blocking device 5 on stray light.

In one embodiment, the light blocking device 5 can also be relatively fixed to the first optical unit 2 in other ways, for example, it can be fixed to the structural parts of the first optical unit 3 by glue; it can also be fixed to the first optical unit 2 by screws. The structural parts of the optical unit 3 are fixed; it can also be integrally injection molded with the structural parts of the first optical unit 3 to form a complete integral structure.

Further, the first preset included angle is 45°, and the second preset included angle is 90°, that is, the included angle between the central axis of the first optical unit 3 and the central axis of the first lens unit 2 is 45°, and the second preset included angle is 45°. The central axis of the optical unit 4 and the central axis of the first lens unit 2 are perpendicular to each other, and the included angle between the central axis of the first optical unit 3 and the central axis of the second optical unit 4 is 45°. Therefore, when the light beam reaches the first optical unit 3 after passing through the first lens unit 2, the incident angle of the light beam is 45°, and the reflection angle is also 45°, so the included angle between the reflected light beam and how light beam is 90°; when the light beam When reaching the second optical unit 4, the incident angle of the light beam is 0°, and the reflection angle is also 0°.

Please refer to FIG. 1 , further, the image generating unit 1 is a microdisplay, and the microdisplay is coaxial with the first lens unit 2, and the first lens unit 2 includes at least one lens. Specifically, the use of a micro-display is beneficial to reduce the weight of the head-mounted display optical system. The size of the microdisplay is 0.29 inches to 1.3 inches (1 inch is about 2.54 centimeters), which can be set as required, preferably 0.71 inches, and the aspect ratio of the microdisplay is preferably 16:9. The screen size formed after the image display area of the microdisplay passes through the first lens unit 2, the first optical unit 3 and the second optical unit 4 is: the length H in the horizontal direction is 15.718 centimeters, and the width V in the vertical direction is 8.842 cm, so is 7.859 cm, is 4.421 cm, that is, the aspect ratio of the screen is the same as that of the microdisplay, and the field of view fov(H) in the horizontal direction satisfies The field of view fov(V) in the vertical direction satisfies Where f is the effective focal length of the head-mounted display optical system. In this embodiment, the viewing angle of the head-mounted display optical system (referring to the viewing angle of the diagonal line of the screen here) is greater than 40°, thereby having a large viewing angle and thus having a better user experience. The field of view in the horizontal direction is set to be larger than the field of view in the vertical direction. The main consideration is that the field of view of the human eye in the horizontal direction is larger than the field of view in the vertical direction, so that the user experience can be guaranteed. better.

Please refer to FIG. 8 , in this embodiment, for better description, consider that the direction where the central axis of the microdisplay is located is the Y direction, the direction where the central axis of the second optical unit 4 is located is the X direction, and the X direction and the Y direction are are perpendicular to each other, the central axis of the microdisplay and the central axis of the second optical unit 4 perpendicularly intersect the first optical unit 3 .

Further, the first lens unit 2 includes a first lens 21 and a second lens 22 sequentially arranged along the optical path, and the first lens 21 and the second lens 22 are coaxial and coaxial with the image generating unit 1 . Adopting the coaxial method not only makes the overall structure of the head-mounted display optical system simpler, but also makes processing and assembly easier, and is conducive to improving the imaging quality of the head-mounted display optical system.

Due to the positional offset and angular deflection of the various components in the head-mounted display optical system, the optical system will not be coaxial, thereby affecting the imaging quality.

In this embodiment, the included angle between the central axis of the first lens 21 and the Y direction is not greater than 3°, and the included angle between the central axis of the second lens 22 and the Y direction is not greater than 3°. Specifically, the deflection angle of the first lens 21 around the X direction is not more than 3°, and the deflection angle of the first lens 21 around the Y direction is not more than 3°; the deflection angle of the second lens 22 around the X direction is not more than 3°, and the second The deflection angle of the lens 22 around the Y direction is not greater than 3°. Preferably, the deflection angle of the first lens 21 around the X direction is not more than 0.5°, the deflection angle of the first lens 21 around the Y direction is not more than 0.5°; the deflection angle of the second lens 22 around the X direction is not more than 0.5°, the second The deflection angle of the lens 22 around the Y direction is not greater than 0.5°, so as to ensure good imaging quality of the head-mounted display optical system.

In this embodiment, the displacement of the first lens 21 in the X direction is not more than 2 mm, and the displacement of the first lens 21 in the Y direction is not more than 2 mm; the displacement of the second lens 22 in the X direction is not more than 2 mm. Beyond 2 millimeters, the second lens 22 is shifted in the Y direction by no more than 2 millimeters. Preferably, the displacement of the first lens 21 in the X direction does not exceed 0.1 mm, the displacement of the first lens 21 in the Y direction does not exceed 0.1 mm; the displacement of the second lens 22 in the X direction does not exceed 0.1 mm , the displacement of the second lens 22 in the Y direction does not exceed 0.1 mm, thereby ensuring good imaging quality of the head-mounted display optical system.

Furthermore, the surface shapes of the first lens 21 and the second lens 22 are both spherical, and both are made of plastic through injection molding or hot pressing. The processing method is simple, and it is easy to produce and assemble in batches. In this embodiment, both the first lens 21 and the second lens 22 are made of a resin material, preferably polymethyl methacrylate (PMMA), which is easy to produce and cheap, and light in texture, which is conducive to reducing manufacturing costs and overall weight. In other embodiments, the first lens 21 and the second lens 22 can also be made of glass.

It should be understood that the first lens unit 2 may also include only one lens, or may include more than two lenses, for example, may include three lenses, etc., which is not limited here.

8 and 9, further, the first optical unit 3 includes a first optical lens 31, the surface of the first optical lens 31 facing the first lens unit 2 is the first upper surface 311, and the first optical lens 31 faces away from The surface of the first lens unit 2 is the first lower surface 312 .

In one embodiment, a first semi-reflective film is provided on the first upper surface 311 , and a first anti-reflection film is provided on the first lower surface 312 . The semi-reflective and semi-permeable film here means that part of the incident light beam is reflected after passing through the semi-reflective and semi-permeable film, and part of it is transmitted; here, the anti-reflection film can reduce reflection and increase transmission. When the light beam is incident on the first optical lens 31 through the first lens unit 2, the light beam contacts the first upper surface 311 of the first optical lens 31, a part of the incident light beam is reflected, and a part is transmitted; the transmitted part reaches the first optical lens 31. The lower surface 312, and emerges from the first optical lens 31 under the effect of the first anti-reflection coating, and the emitted light beam reaches the light blocking device 5 and is absorbed; the reflected part reaches the second optical unit 4 and then reflects back to the second optical unit 4 An optical lens 31, and passes through the first upper surface 311 and the first lower surface 312 in turn, and emerges from the first optical lens 31 under the effect of the first anti-reflection coating, and the emitted light beam reaches the user's eyes 6, so that the user See images of microdisplay launches.

In one embodiment, the first anti-reflection film is arranged on the first upper surface 311, the first semi-reflective and semi-transparent film is arranged on the first lower surface 312, and the process after the light beam reaches the first optical lens 31 is similar to the above-mentioned situation , which will not be repeated here.

Preferably, the transmittance ratio (that is, the ratio of transmitted light to reflected light) of the first semi-reflective and semi-transparent film is 7:3, that is, when the incident light beam passes through the first semi-reflective and semi-transparent film, 70% of the incident light is transmitted, 30% of incident light is reflected. As the ratio of the transmitted light is larger, the bottom light is reflected by the first optical lens 31 and enters the user's eyes 6 less, so the influence of reflected light caused by ambient stray light is smaller, and the user experience is better.

It should be understood that the transmittance ratio of the first semi-transverse and semi-permeable film can also be other values, for example, the transmittance ratio can be 5:5, 6:4, 8:2 or 9:1, etc., which can be set as required, here There are no restrictions.

In this embodiment, the included angle between the central axis of the first optical lens 31 and the central axis of the first lens unit 2 is 45°, and the included angle between the central axis of the first optical lens 31 and the Y direction is no greater than 5°. Specifically, the angle of deflection of the first optical lens 31 around the X direction is not more than 5°, and the angle of deflection of the first optical lens 31 around the Y direction is not more than 5°; preferably, the angle of deflection of the first optical lens 31 around the X direction is not more than 5°. If it is greater than 0.5°, the deflection angle of the first optical lens 31 around the Y direction is not greater than 0.5°, thereby ensuring good imaging quality of the head-mounted display optical system.

In one embodiment, the first optical lens 31 is a non-planar mirror, the deviation of the first optical lens 31 in the X direction is no more than 1 millimeter, and the deviation of the first optical lens 31 in the Y direction is no more than 1 millimeter; preferably Specifically, the displacement of the first optical lens 31 in the X direction does not exceed 0.1 mm, and the displacement of the first optical lens 31 in the Y direction does not exceed 0.1 mm, so as to ensure good imaging quality of the head-mounted display optical system.

In one embodiment, the first optical lens 31 is a flat mirror, at this time its offset in the X direction and Y direction does not affect its imaging quality, so its assembly is simpler, which is conducive to the formation of a good head-mounted display optical system image quality.

8 and 10, further, the second optical unit 4 includes a second optical lens 41, the surface of the second optical lens 41 facing the first optical unit 3 is the second upper surface 411, and the second optical lens 41 faces away from the The surface of the first optical unit 3 is the second lower surface 412 .

In one embodiment, a second semi-reflective film is provided on the second upper surface 411 for reflecting the light beam from the first optical unit 3; a second anti-reflection film is provided on the second lower surface 412 for Light from the environment is transmitted. On the one hand, after the light beam from the first optical unit 3 reaches the second optical lens 41, the light beam contacts the second upper surface 411 of the second optical lens 41, a part of the incident light beam is reflected, and a part is transmitted; the transmitted part reaches The second lower surface 412 , and exits from the second optical lens 41 to the outside of the head-mounted display optical system under the action of the second anti-reflection coating; the reflected part reaches the first optical lens 31 . On the other hand, the light from the environment enters the head-mounted display optical system after passing through the second lower surface 412 and the second upper surface 411 of the second optical lens 41 in sequence, and enters the first optical lens 31; The ambient light beam at the optical lens 31 passes through the first upper surface 311 and the first lower surface 312 in sequence, and emerges from the first optical lens 31 under the effect of the first anti-reflection coating, and the emitted light beam reaches the user's eyes 6, thereby The user can also see the environment image, that is, the user can see the image of the microdisplay and the environment image at the same time, so as to realize the interaction between the external scene and the screen information. The second anti-reflection film is arranged on the second lower surface 412 of the second optical lens 41, which is conducive to the output of the light beams that need to be emitted in the head-mounted display optical system to the outside, reducing the influence of stray light on the image quality, and at the same time, the ambient light can effectively It is transmitted into the display optical system, so that users can obtain brighter environmental images, improve imaging quality, and improve user experience.

In one embodiment, the second anti-reflection film is arranged on the second upper surface 411, and the second semi-reflective and semi-transparent film is arranged on the second lower surface 412, and the process after the light beam reaches the second optical lens 41 is similar to the above-mentioned situation , which will not be repeated here.

It should be understood that the transmittance ratio of the second semi-transverse and semi-permeable membrane can be set as required, for example, it can be 5:5, 6:4, 7:3, 8:2 or 9:1, etc., which is not limited here .

Further, the second optical lens 41 is a spherical mirror with equal thickness, an aspherical mirror with equal thickness or a free-form surface mirror with equal thickness. Preferably, the second optical lens 41 is a spherical mirror with equal thickness, which is easy to process. The equal thickness here means that the thicknesses of the second optical lens are equal everywhere.

Further, the radius of curvature R of the second optical lens 41 satisfies R>2(d1+d2), wherein d1 refers to the distance between the central axis of the second optical lens 41 and the intersection point of the second optical lens 31 to the second optical lens 41 The distance between the central axis and the intersection of the first optical glass 31, d2 refers to the intersection of the central axis of the microdisplay and the second lens 22 near the first optical glass 31 to the central axis of the microdisplay and the first optical glass 31 The distance of the intersection point is more conducive to imaging.

In this embodiment, the central axis of the second optical lens 41 is perpendicular to the central axis of the microdisplay, and the angle between the central axis of the second optical lens 41 and the Y direction is not greater than 0.5°. Specifically, the deflection angle of the second optical lens 41 around the X direction is not more than 0.5°, and the deflection angle of the second optical lens 41 around the Y direction is not more than 0.5°; preferably, the deflection angle of the second optical lens 41 around the X direction is not more than 0.5°. If it is greater than 0.1°, the deflection angle of the second optical lens 41 around the Y direction is not greater than 0.1°, thereby ensuring good imaging quality of the head-mounted display optical system.

In this embodiment, the offset of the second optical lens 41 in the X direction is not more than 0.5 mm, and the offset of the second optical lens 41 in the Y direction is not more than 0.5 mm; preferably, the second optical lens 41 is in the X direction. The deviation in the direction is not more than 0.05 mm, and the deviation of the second optical lens 41 in the Y direction is not more than 0.05 mm, so as to ensure good imaging quality of the head-mounted display optical system.

In one embodiment, the second optical lens 41 is made of glass material, and a photochromic material is evenly distributed in the second optical lens 41 . Specifically, the photochromic material and the glass material are evenly mixed to form the second optical lens 41 , so that the second optical lens 41 can achieve a uniform color changing effect when changing color.

In one embodiment, the second optical lens 41 is made of resin material, and the surface of the second optical lens 41 is evenly coated with a photochromic coating, so that the second optical lens 41 can achieve a uniform color changing effect when changing color.

In one embodiment, the second optical lens 41 is made of resin material, and the surface of the second optical lens 41 is uniformly permeated with photochromic material, so that the second optical lens 41 can achieve uniform color changing effect when changing color.

Photochromism refers to the reversible process in which the absorption spectrum of a photochromic material changes when it is irradiated with a specified wavelength. Photochromic materials include silver halide systems, diarylethenes, fulgid anhydrides, spiropyrans, spirorazines, azos and related heterocyclic compounds. In this embodiment, when the second optical lens 41 with the photochromic material is in an environment with strong sunlight, the second optical lens 41 will be irradiated by short-wavelength rays such as ultraviolet rays. At this time, the second optical lens 41 The color of the second optical lens 41 will be evenly darkened, and the transmittance of the second optical lens 41 to ambient light will be reduced, so that the amount of light entering the head-mounted display optical system through the second optical lens 41 will be reduced, and the user will be able to use the light in an environment with strong light. It can still be used comfortably under the environment; when the ambient light is dark, the color of the second optical lens 41 becomes lighter, and the transmittance of the second optical lens 41 to the ambient light increases, so that the light entering the head-mounted display through the second optical lens 41 The increased amount of light in the optical system allows users to use it normally in low-light environments.

Please refer to FIG. 11 , further, the projected area of the first optical lens 31 in the direction of the second optical lens 41 is not smaller than the size of the second optical lens 41, so that the light entering the head-mounted display optical system through the second optical lens 41 All ambient light beams can reach the first optical lens 31, and reach the user's eyes 6 after passing through the first optical lens 31, so that the external image seen by the user has better consistency, and at the same time, the external image and the screen image have a better consistency. Good consistency, better user experience. Referring to FIG. 12 , correspondingly, when the projected area of the first optical lens 31 in the direction of the second optical lens 41 is smaller than the size of the second optical lens 41 , on the one hand, it enters the head-mounted display through the second optical lens 41 A part of the ambient light beam in the optical system will pass through the first optical lens 31 before reaching the user's eyes 6. This part of the light is relatively dark, while a part will directly reach the user's eyes 6. This part of the light is relatively bright. At this time, the user sees Some areas of the external image will be bright and some areas will be dark, the consistency of the external image is not good; on the other hand, the screen image and the external image cannot be well matched, and the consistency between the two is low. Easily fatigued.

Preferably, the projected area of the first optical lens 31 in the direction of the second optical lens 41 is the same as the size of the second optical lens 41, which not only ensures that the external image seen by the user has a good consistency, but also helps reduce the wear on the head. Displays the overall dimensions of the optical system.

The pupil size of the human eye is generally 2 mm to 8 mm, and the pupil size becomes larger as the ambient brightness decreases, and the larger exit pupil diameter is conducive to the alignment between the head-mounted display optical system and the center of the pupil of the human eye. Bit tolerance; the exit pupil diameter of the head-mounted display optical system provided in this embodiment is greater than 8 millimeters, and the exit pupil distance is greater than 15 millimeters, so that the user has a better user experience when viewing. Preferably, the exit pupil diameter of the head-mounted display optical system provided in this embodiment is 8 mm, and the exit pupil distance is 18 mm, so as to have a good user experience.

In one embodiment, the field of view of the head-mounted display optical system is 45°, and its corresponding MTF curve (Modulation Transfer Function, Modulation Transfer Function) is shown in FIG. 13 . Since when the spatial frequency is 30lp/mm, the higher the MTF value, the higher the resolution, and the higher the image quality; as can be seen from Figure 13, the curves in the figure represent the MTF curves under different fields of view, and each field of view The MTF curves of the MTF curves are greater than 0.2 when the spatial frequency is 30 lp/mm, which is far greater than the resolution limit of the human eye. Therefore, the imaging quality of the head-mounted display optical system of this embodiment is very high.

Further, in order to ensure the compactness of the head-mounted display optical system, the height of the head-mounted display optical system provided by this embodiment in the Y direction is not greater than 100 millimeters; preferably, the height of the head-mounted display optical system in the Y direction is not greater than It is larger than 70 mm, which makes the overall volume of the head-mounted display optical system smaller, easier to wear and carry, and better user experience.

The purpose of this embodiment is also to provide a head-mounted display device, including the above-mentioned head-mounted display optical system.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. A head-mounted display optical system characterized by: including setting gradually along the light path:

an image generating unit for generating and emitting a light beam carrying image information;

a first lens unit for transmitting the light beam and adjusting a propagation direction of the light beam;

the first optical unit is used for reflecting and transmitting light beams, and the central axis of the first optical unit and the central axis of the first lens unit form a first preset included angle;

the second optical unit is used for reflecting the light beam, and the central axis of the second optical unit and the central axis of the first lens unit form a second preset included angle;

the light beam returns to the first optical unit after being reflected by the second optical unit, and enters the eyes of the user after being transmitted by the first optical unit;

the head-mounted display optical system further includes:

and the light blocking device is arranged on one side of the first optical unit, which is opposite to the first lens unit, and is used for blocking ambient stray light from reaching the first optical unit.

2. The head-mounted display optical system according to claim 1, wherein: the light blocking device comprises a fixed part and a light blocking part, the fixed part is used for being connected with the first optical unit, the light blocking part is used for blocking light, connecting parts are arranged on two opposite sides of the fixed part, and the light blocking part is connected with the connecting parts;

the size of the light blocking part is not smaller than the projection area of the first optical unit in the direction of the light blocking device.

3. The head-mounted display optical system according to claim 1, wherein: the first preset included angle is 45 degrees, and the second preset included angle is 90 degrees;

the image generating unit is a microdisplay, and the microdisplay is coaxial with the first lens unit;

the first lens unit includes at least one lens;

the direction of the central axis of the second optical unit is an X direction, the direction of the central axis of the microdisplay is a Y direction, the X direction and the Y direction are perpendicular to each other, and the central axis of the microdisplay and the central axis of the second optical unit are perpendicular to each other and intersect with the first optical unit.

4. The head-mounted display optical system according to claim 3, wherein:

the first lens unit comprises a first lens and a second lens which are arranged along an optical path in sequence, and the first lens and the second lens are coaxial and are coaxial with the image generation unit;

an included angle between the central axis of the first lens and the Y direction is not more than 3 degrees, and an included angle between the central axis of the second lens and the Y direction is not more than 3 degrees;

the first lens is shifted by no more than 2 mm in the X direction and by no more than 2 mm in the Y direction;

the second lens is shifted by no more than 2 mm in the X direction and by no more than 2 mm in the Y direction.

5. The head-mounted display optical system according to claim 3 or 4, wherein: the first optical unit comprises a first optical lens, a first semi-reflecting semi-permeable membrane is arranged on the surface, facing the first lens unit, of the first optical lens, and a first antireflection film is arranged on the surface, facing away from the first lens unit, of the first optical lens;

or,

the surface of the first optical lens facing the first lens unit is provided with a first antireflection film, and the surface of the first optical lens facing away from the first lens unit is provided with a first semi-reflecting semi-permeable film.

6. The head-mounted display optical system according to claim 5, wherein:

the included angle between the central axis of the first optical lens and the Y direction is not more than 5 degrees;

the first optical lens is a non-plane mirror, the offset of the first optical lens in the X direction is not more than 1 mm, and the offset of the first optical lens in the Y direction is not more than 1 mm.

7. The head-mounted display optical system according to claim 3, wherein: the second optical unit comprises a second optical lens, a second semi-reflecting and semi-transmitting film is arranged on the surface, facing the first optical unit, of the second optical lens, and a second antireflection film is arranged on the surface, facing away from the first optical unit, of the second optical lens;

or,

and a second antireflection film is arranged on the surface of the second optical lens facing the first optical unit, and a second semi-reflecting and semi-transparent film is arranged on the surface of the second optical lens facing away from the first optical unit.

8. The head-mounted display optical system according to claim 7, wherein: the central axis of the second optical lens is vertical to the central axis of the micro display, and the included angle between the central axis of the second optical lens and the Y direction is not more than 0.5 degrees;

the second optical lens is shifted by no more than 0.5 mm in the X direction, and the second optical lens 41 is shifted by no more than 0.5 mm in the Y direction.

9. The head-mounted display optical system according to claim 7 or 8, wherein: the second optical lens is an optical lens with equal thickness;

the second optical lens is a resin lens, and the surface of the second optical lens is plated with a photochromic coating;

or,

the second optical lens is a resin lens, and a photochromic material permeates on the surface of the second optical lens;

or,

the second optical lens is a glass lens, and photochromic materials are uniformly distributed in the second optical lens.

10. A head-mounted display device, characterized in that: comprising the head-mounted display optical system according to any one of claims 1 to 9.