CN202008552U - Polarizer and liquid crystal display adopting same - Google Patents

Abstract

The utility model relates to a polarizer and a liquid crystal display using the polarizer. The polarizer can convert all natural light into linearly polarized light, and the polarizer is characterized in that it includes: an anisotropic material body, which is located upstream of the optical path, and is configured to make natural light incident and divide the incident natural light into different polarization directions. two beams of polarized light emitted from the anisotropic material body; and a light adjuster, which is located downstream of the optical path, configured to make one of the two polarized lights emitted from the anisotropic material body incident and to polarize the incident polarized light The direction of the polarized light is completely consistent with that of the other beam of the two beams of polarized light.

Description

Polarizer and liquid crystal display using the polarizer

technical field

The utility model relates to a polarizer, in particular to a polarizing polarizer in a liquid crystal display and a liquid crystal display using the polarizer.

Background technique

The brightness of the liquid crystal display is closely related to the light transmittance of the liquid crystal display. In the design of the existing liquid crystal display backlight, half of the light emitted by the backlight is absorbed by the polarizer of the liquid crystal display, so the energy utilization of the backlight is greatly reduced. Rate.

The Chinese patent application with application number 201010101161.1 discloses a method for completely converting natural light into linearly polarized light. The liquid crystal display formed by this method will pass the polarized light component in the same polarization direction as the polarized transmission part of the liquid crystal screen in the light emitted by the backlight, but for the light component perpendicular to the polarization direction of the polarized transmission part, it is not like the traditional polarization It is absorbed as in the film, but is reflected back to the direction of the light source, and its vibration direction is rotated to the same polarization direction as the polarized transmission part by the optically rotating reflective part arranged behind the light source, and then reflected, so as to realize almost the light emitted by the backlight All the light is incident on the LCD screen.

However, in the method disclosed in the Chinese patent application with the application number 201010101161.1, since the polarized light component in the orthogonal direction is recycled by being reflected back and forth by the light reflection member, the conversion efficiency must be lost to a certain extent. In addition, the implementation of the recovery optical path is relatively complicated when recovery is performed by reflection, so it is difficult to apply the above method to liquid crystal displays in practical applications.

Utility model content

The purpose of this utility model is to solve the problems of the unsatisfactory conversion efficiency in the above-mentioned background technology and the technical difficulties in applying it to liquid crystal displays. The directions are divided into two beams and processed separately, thereby realizing a polarizer with high conversion efficiency and a display using the polarizer.

According to the polarizer of the first aspect of the utility model, all natural light can be converted into linearly polarized light, and the polarizer is characterized in that it includes: an anisotropic material body, which is located upstream of the optical path, and is configured so that natural light is incident and the incident natural light is divided into two beams of polarized light with different polarization directions and emitted; and a light adjuster, which is located downstream of the optical path, is configured so that one of the two beams of polarized light emitted from the anisotropic material body The incident polarized light is incident and the polarization direction of the incident polarized light is completely consistent with the polarization direction of the other beam of the two beams of polarized light before being emitted.

Utilizing the polarizer of the utility model avoids using the reflection light path for recycling, so the light path structure is easy to control and realize, and can be simply and effectively applied to liquid crystal displays. Moreover, the polarizer of the utility model makes use of this simple optical path structure to convert almost all the light emitted by the backlight into linearly polarized light with the same polarization direction, which greatly improves the light conversion efficiency and light transmittance of the polarizer, thereby The effect of saving backlight energy in the liquid crystal display is realized.

In the polarizer of the present invention, the anisotropic material body is preferably a birefringent crystal. Among them, in a polarizer including a birefringent crystal, the light adjuster is preferably a half-wave plate. Preferably, the polarizer of the present invention further includes a mechanism, which is located upstream of the anisotropic material body in the optical path, and is configured to gather the natural light emitted by the light source into a striped beam and incident the striped beam to the The anisotropic material body.

By using the polarizer in the preferred aspect of the utility model, it is possible to convert the light emitted by a point light source or a line light source with a relatively simple process, so that it can be applied to a liquid crystal display with a point light source or a line light source as a backlight source. Improving the light conversion efficiency of polarizers and backlight utilization in liquid crystal displays.

In the polarizer of the present invention, the anisotropic material body is preferably a liquid crystal lens. Wherein, in the polarizer including the liquid crystal lens, the light adjuster preferably includes an array composed of a plurality of half-wave plates, and two adjacent half-wave plates in the array do not have any phase to the polarized light. The connectors composed of transparent media with retardation effect are connected, and the polarized light of one polarization direction emitted from the liquid crystal lens enters the half-wave plate in the array, while the polarized light of the other polarization direction enters the array connectors.

Utilizing the polarizer in the preferred aspect of the utility model, the light emitted by the surface light source can be converted and processed through the liquid crystal lens, so as to be applied to a liquid crystal display with a surface light source as a backlight source, so as to improve the light conversion efficiency of the polarizer and the liquid crystal display The backlight utilization in .

According to another aspect of the present invention, a liquid crystal display is provided, which includes any polarizer described in the first aspect and the preferred aspects of the present invention.

Description of drawings

Fig. 1 is a schematic structural diagram showing a polarizer according to an embodiment of the present invention.

Fig. 2 is a schematic structural view showing a polarizer according to another embodiment of the present invention.

Detailed ways

Preferred embodiments of the polarizer according to the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows a schematic structural view of a polarizer 1 according to a preferred embodiment of the present invention. As shown in FIG. 1 , the polarizer 1 of the present invention includes an anisotropic material body 11 and a light adjuster 12 .

Assuming that the light source emits scattered natural light, before it enters the polarizer 1, the scattered natural light is first converged into a strip beam, which is indicated by an arrow in the figure. The method of converging the natural light emitted by the light source into a striped beam can be known in the art, for example, using a lens for converging, or using a reflective film to surround the light source so that the scattered light is emitted from the slit opening after multiple reflections.

Subsequently, the strip beam is incident on the anisotropic material body 11 of the polarizer 1 . In this embodiment, the anisotropic material body 11 is, for example, a birefringent crystal. The incident strip beam is decomposed into two beams of polarized light with different polarization directions by the birefringent crystal. Shown in this embodiment is to be decomposed into the e-ray (indicated by a short horizontal arrow in the figure) whose polarization direction is parallel to the main section of the birefringent crystal and the O-ray whose polarization direction is perpendicular to the main section of the birefringent crystal (indicated by a circle among the figures). Indicated by dotted arrows).

Next, one of the two polarized lights is made incident on the light adjuster 12 of the polarizer 1 to deflect the vibration direction of the polarized light by an angle. In this embodiment, the light adjuster 12 is, for example, a half-wave plate. As shown in FIG. 1 , for example, O light whose polarization direction is perpendicular to the main section of the birefringent crystal is incident on a half-wave plate. The angle of the optical axis of the half-wave plate or the angle of the optical axis of the birefringent crystal is adjusted to control the relative angle of the two optical axes. In this embodiment, the relative angle of the two optical axes is controlled to be 45 degrees, so that the polarization direction of the outgoing light from the half-wave plate is perpendicular to the polarization direction of the incident light, that is, it is consistent with the polarization direction of the e-light. No processing is done on the other beam of e-ray whose polarization direction is parallel to the main section of the birefringent crystal. Therefore, the light beam emitted by the polarizer 1 is linearly polarized light with completely consistent polarization directions.

The above description is based on an example in which the O light whose polarization direction is perpendicular to the main section of the birefringent crystal is deflected by a half-wave plate to make the polarization directions of the two polarized lights consistent. However, it should be understood that the above-mentioned embodiments are not limiting. The polarized light of any polarization direction after beam splitting is deflected by the light adjuster, so that the polarization direction of the outgoing light is consistent with the polarization direction of the other polarized light, and the polarization direction of the other polarized light is not adjusted. Any processing of polarized light in one polarization direction can also achieve the same polarization direction of the two polarized lights, thereby outputting linearly polarized light.

A polarizer 2 according to another embodiment of the present invention will be described below with reference to FIG. 2 . As shown in FIG. 2 , the polarizer 2 includes a liquid crystal lens 21 and a half-wave plate array 22 .

The hollow arrows in FIG. 2 represent natural light, which is allowed to directly enter the liquid crystal lens 21 of the polarizer 2 . As a special anisotropic material, the liquid crystal lens 21 can change the birefringence coefficient of the liquid crystal by controlling the voltage applied across the liquid crystal, thereby changing the phase difference of light passing through the liquid crystal lens 21 . Natural light passes through each unit in the array of liquid crystal lenses 21 and is split into polarized lights of two different polarization directions. For example, such a situation is shown in FIG. The polarized light emitted by the liquid crystal lens 21 is split into the e-light (shown by a short horizontal arrow in the figure) whose polarization direction is parallel to the main section of the liquid crystal lens, and the O-light (shown by a circle in the figure) whose polarization direction is perpendicular to the main section of the liquid crystal lens. point arrow).

Subsequently, the polarized light emitted from the liquid crystal lens 21 enters the half-wave plate array 22 . As shown in Figure 2, the half-wave plate array 22 includes a plurality of half-wave plates represented by black rectangular blocks and connecting pieces represented by white rectangular blocks between every two half-wave plates . In the half-wave plate array 22, the connecting piece represented by the white rectangular block is a transparent medium that does not have any phase retardation effect on the incident polarized light, and is only used to connect two adjacent half-wave plates .

Make the polarized light of a kind of polarization direction in the polarized light of each unit exiting in the array of liquid crystal lens 21, for example shown in Fig. A half wave plate in the wave plate array 22. Adjust the optical axis angle of the half-wave plate or adjust the voltage applied to the two ends of the liquid crystal of the liquid crystal lens 21, so that the polarization direction of the polarized light passing through the half-wave plate is consistent with the e light, that is, parallel to the liquid crystal lens main section. And for the polarized light of another kind of polarized direction in the polarized light that exits from each unit in the array of liquid crystal lens 21, for example e light, then make it pass through the connector in the half-wave plate array 22 without generating any phase delay. Therefore, the light emitted by the polarizer 2 is linearly polarized light with completely consistent polarization directions.

Compared with the prior art, the polarizer of the present invention and the liquid crystal display using the polarizer described in the above preferred embodiments have improved conversion efficiency, thereby solving the problem of low backlight utilization in liquid crystal displays. At the same time, the polarizer of the utility model also overcomes the problem that the existing technology of recovering reflected light is difficult to control and realize, so it can be simply and effectively applied to liquid crystal displays to replace the existing polarizer.

Claims (7)

1. A polarizer capable of converting natural light emitted by a light source into linearly polarized light, characterized in that it comprises: An anisotropic material body, which is located upstream of the light path, is configured such that natural light is incident and the incident natural light is divided into two beams of polarized light with different polarization directions to be emitted; and The light adjuster, which is located downstream of the optical path, is configured to make one of the two beams of polarized light emitted from the anisotropic material body incident and to make the polarization direction of the incident one beam of polarized light different from that of the two beams of polarized light The other beam of light is emitted with the same polarization direction. 2. The polarizer of claim 1, wherein the body of anisotropic material is a birefringent crystal. 3. The polarizer of claim 2, the light modulator being a half wave plate. 4. The polarizer according to any one of claims 1-3, further comprising a mechanism located above the body of anisotropic material in the light path and configured to gather natural light emitted by the light source into strips The beam and the strip beam are incident on the anisotropic material body. 5. The polarizer according to claim 1, wherein the body of anisotropic material is a liquid crystal lens. 6. The polarizer according to claim 5, wherein said light adjuster comprises an array composed of a plurality of half-wave plates, and two adjacent half-wave plates in the array are polarized The light has any phase retardation of the transparent medium to connect, and wherein the polarized light of one polarization direction emitted from the liquid crystal lens enters the half-wave plate in the array, and the other polarized light direction of polarized light incident on the connectors in the array. 7. A liquid crystal display, characterized by comprising the polarizer according to any one of claims 1-6.

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