CN112213855B - Display device and optical waveguide lens - Google Patents

Abstract

The application relates to a display device and optical waveguide lens belongs to display device technical field, and this display device includes: an optical waveguide lens including a plurality of functional regions including a light-incoupling region; the transparent lens is attached to the substrate corresponding to the light coupling-in area in the optical waveguide lens; the light is refracted by the transparent lens and then enters the optical waveguide lens, and is coupled into the optical waveguide lens through the light coupling-in area for total reflection transmission; the limitation of the existing optical waveguide lens can be solved, the deviation of the positive angle of an image watched by human eyes is large, and the image display effect is poor; the requirement of large-range incident light causes the problem of complex structure of the front-end optical system; because the light only needs to be incident within a small angle range, the structural complexity of the front-end optical system can be reduced; meanwhile, the refraction effect of the transparent lens can also improve the condition that the positive angle of an image formed by the light coupled out by the optical waveguide lens is larger when the image deviates from the image watched by human eyes.

Description

Display device and optical waveguide lens

technical field

The present application relates to a display device and an optical waveguide lens, belonging to the technical field of display equipment.

Background technique

Augmented Reality (AR) technology is a new technology that "seamlessly" integrates real world information and virtual world information. Visual information, sound, taste, touch, etc.), are simulated and simulated by photoelectric information technology and then superimposed, and the virtual information is applied to the real world and perceived by human senses, so as to achieve a sensory experience beyond reality. The real environment and virtual objects are superimposed on the same picture or space in real time and exist at the same time, realizing a highly realistic fusion of virtual and real. One of the characteristics of the AR system: adding and positioning virtual objects in the three-dimensional scale space.

Most of the current mainstream near-eye augmented reality display devices use the principle of optical waveguides. Publication No.: 106338832A discloses a single-piece holographic diffractive optical waveguide lens, the optical waveguide lens includes a layer of optical waveguide medium and a first functional area, a second functional area and a third functional area arranged on the optical waveguide ; The external image beam is incident through the first functional area, coupled into the optical waveguide, propagated to the second functional area under the action of the total reflection of the optical waveguide, diffracted by the second functional area, and under the action of the total reflection of the optical waveguide , continue to propagate to the third functional area, and finally diffracted by the third functional area to emit the image beam to the external space.

However, in order to meet the requirement of total reflection and transmission of light in the optical waveguide, the light incident to the first functional region needs to be incident in a wide range relative to the normal to the surface of the optical waveguide. Correspondingly, the exit angle is also large relative to the normal to the surface of the optical waveguide. range out. At this time, due to the limitation of the existing optical waveguide lens, the image viewed by the human eye deviates greatly from a positive angle, and the image display effect is not good; and the requirement of a large range of incident light leads to a complex structure of the front-end optical system.

SUMMARY OF THE INVENTION

The present application provides a display device and an optical waveguide lens, which can solve the limitation of the existing optical waveguide lens, the image viewed by the human eye deviates from a positive angle, and the image display effect is not good; and the demand for a large range of incident light leads to the front end The structure of the optical system is complex. This application provides the following technical solutions:

In a first aspect, a display device is provided, the display device comprising:

an optical waveguide lens, comprising a plurality of functional regions, the plurality of functional regions including light coupling-in regions;

a transparent lens, which is attached to the substrate corresponding to the light coupling area in the optical waveguide lens; the light is refracted by the transparent lens and then incident on the optical waveguide lens, and is coupled into the optical waveguide lens through the light coupling area Optical waveguide lens for total reflection transmission.

Optionally, the incident angle of the light to the transparent lens is smaller than the critical angle for total reflection.

Optionally, the transparent lens is a transparent prism attached to a substrate corresponding to the light coupling region.

Optionally, the refractive index range of the transparent prism is the same as the refractive index range of the optical waveguide sheet.

Optionally, the refractive index range of the transparent prism is [1.4, 2].

Optionally, the transparent prism is a triangular prism.

Optionally, the transparent lens is seamlessly attached to the substrate corresponding to the light coupling region.

Optionally, the plurality of functional regions are located on the upper surface of the optical waveguide sheet; or, are located on the lower surface of the optical waveguide sheet; or, part of the functional regions are located on the upper surface of the optical waveguide sheet, and another part is located on the lower surface of the optical waveguide sheet the lower surface of the optical waveguide lens.

Optionally, each functional region includes at least one structural unit pixel, and the structural unit pixel is composed of periodic nanogratings.

In a second aspect, an optical waveguide lens is provided, the optical waveguide lens includes a plurality of functional regions; the plurality of functional regions include light coupling regions; the positions corresponding to the light coupling regions have protruding settings The transparent lens; the light is refracted by the transparent lens and then enters the light coupling area, and is coupled into the optical waveguide lens through the light coupling area for total reflection transmission.

The beneficial effect of the present application is that: by attaching a transparent lens to the substrate corresponding to the light coupling area of the optical waveguide lens, the light is refracted by the transparent lens and then incident on the optical waveguide lens; Before entering the area, the light is received at a small angle of incidence, and the light is refracted to enter the light coupling area at a large angle, so that the light can be totally reflected in the optical waveguide lens after being coupled by the light coupling area. Transmission; it can solve the limitation of the existing optical waveguide lens, the image viewed by the human eye deviates from a positive angle, and the image display effect is not good; and the demand for a large range of incident light leads to the complex structure of the front-end optical system; It needs to be incident in a small angle range, so the structural complexity of the front-end optical system can be reduced; at the same time, the refraction effect of the transparent lens can also improve the image formed by the out-coupled light from the optical waveguide lens. Happening.

The above description is only an overview of the technical solutions of the present application. In order to understand the technical means of the present application more clearly and implement them in accordance with the contents of the description, the preferred embodiments of the present application and the accompanying drawings are described in detail below.

Description of drawings

FIG. 1 is a schematic diagram of light transmission by a waveguide lens provided by an embodiment of the present application;

FIG. 2 is a schematic diagram of light transmission by a waveguide lens provided by another embodiment of the present application;

FIG. 3 is a schematic diagram of light transmission by a display device according to an embodiment of the present application.

Detailed ways

The specific implementations of the present application will be described in further detail below with reference to the accompanying drawings and embodiments. The following examples are used to illustrate the present application, but are not intended to limit the scope of the present application.

FIG. 1 is a schematic structural diagram of an optical waveguide lens provided by an embodiment of the present application. As shown in FIG. 1 , the optical waveguide lens includes a plurality of functional regions ( 11 , 12 and 13 ).

Optionally, a plurality of functional regions are located on the upper surface of the optical waveguide lens; or, on the lower surface of the optical waveguide lens; or, part of the functional area is located on the upper surface of the optical waveguide lens, and another part is located on the lower surface of the optical waveguide lens.

Optionally, each functional region includes at least one structural unit pixel, and the structural unit pixel is composed of periodic nanogratings.

Illustratively, the plurality of functional regions includes a light coupling region 11 . The light coupling region 11 is used for coupling light into the optical waveguide lens, and the coupled light needs to satisfy the condition of total reflection and transmission in the optical waveguide lens. Optionally, the light coupling region 11 includes three kinds of structural unit pixels, and the three kinds of structural unit pixels are respectively used for coupling red, green, and blue image light rays. In one example, the periodic nanograting of the structural unit pixel in the light coupling region 11 has a period of 200-600 nm, a duty cycle of 0.1-0.7, and a depth of 100-500 nm.

Optionally, the plurality of functional regions includes a light outcoupling region 12 . The light coupling-out area 12 is used for coupling the light transmitted in the optical waveguide lens out of the optical waveguide lens. The light coupling-out area 12 includes three kinds of structural unit pixels, and the three kinds of structural unit pixels are used for coupling red, green, and blue image light respectively. In one example, the period of the periodic nanograting of the structural unit pixel in the light coupling region 12 is 200-600 nm (the same as the period of the periodic nanograting of the structural unit pixel in the light coupling region 11 ), and the duty cycle is Between 0.1-0.7, the depth is between 100-500nm.

Optionally, the plurality of functional areas includes a light turning area 13 . The light turning region 13 is used for turning the light coupled from the light coupling-in region 11 to the light coupling-out region 12 . The light turning area 13 includes three kinds of structural unit pixels, and the three kinds of structural unit pixels are respectively used for coupling red, green, and blue image light rays. In one example, the period of the periodic nanograting of the structural unit pixel in the light turning region 13 is between 150-500 nm, the duty ratio is between 0.1-0.7, and the depth is between 100-500 nm.

Schematically, the orientation of the periodic nanograting in the light inflection region 13 is 45° from the orientation of the periodic nanograting in the light coupling region 11 ; the orientation of the periodic nanograting in the light coupling region 12 is the same as that in the light coupling region 11 . The periodic nanogratings are oriented at 90°.

In the optical waveguide lens shown in FIG. 1 , the light coupling region 11 has a broadband diffraction function. The diffracted light rays of the red, green and blue image rays need to meet the conditions of total reflection in the optical waveguide lens, so that the light coupled into the optical waveguide lens through the light coupling area 11 can be totally reflected and transmitted in the optical waveguide lens. The light inflection area 13 diffracts to the light coupling-out area 12; after diffracted by the light coupling-out area 12, the three-color image light is coupled out of the optical waveguide lens and transmitted to the human eye, and is synthesized by the human eye to realize color augmented reality display.

It should be supplemented that FIG. 1 only takes the optical waveguide lens including 3 functional areas as an example for description. In actual implementation, the number of functional areas may be 2 or more than 3. This embodiment does not apply to the functional areas. quantity is limited.

For the optical waveguide lens shown in Figure 1, the diffracted light generated by the incident light diffracted by the light coupling region 11 must meet the requirements of total internal reflection of the waveguide lens, and the light must be incident at a large angle relative to the surface normal of the optical waveguide lens. At this time, The light diffracted by the light coupling region 11 can be totally reflected and transmitted in the optical waveguide lens. The period, field angle and incident light wavelength of the periodic nanograting in the light coupling region 11 need to satisfy Λ1=λ/(1+sin FOV/2). Wherein, Λ1 is the period of the periodic nano-grating in the light coupling region 11 , FOV is the field of view, and λ is the wavelength of the incident light.

Referring to Figure 2, assuming that the light rays are incident at two critical angles that can be totally reflected and transmitted in the optical waveguide lens (respectively shown by the light path shown by the solid line and the light path shown by the dotted line), the angle between the two critical angles is 50°. Since the light constituting the image will be coupled into the optical waveguide lens at the same diffraction angle when it is incident on the light coupling area 11, it will propagate under the condition of total reflection, and the light will be emitted at an angle parallel to the incident light when it is output, and the image can be completed Therefore, the field of view formed by the light coupled out of the light coupling out area 12 is 50°.

When the light is output from the light out-coupling area 12, since the total reflection incident angle is the same, and the period of the periodic nano-grating in the light in-coupling area 11 and the light out-coupling area 12 is the same, at each total reflection exit point, the light is the same as the original one. The light rays are parallel, which will cause the imaging to shift to a certain extent at different exit pupil positions. When the imaging plane is less than 1 meter, the image formed by the outgoing rays deviates from the positive angle when the human eye views the image. In addition, at this time, the angle between the two critical angles is relatively large, and the requirement of such a wide range of incident light leads to a complicated structure of the front-end optical system.

Based on the above technical problems, in this application, a transparent lens is introduced into the optical waveguide lens at the position corresponding to the light coupling area 11 , and the transparent lens is used to receive the light at a small angle of incidence before the light enters the light coupling area 11 . and refracted the light to enter the light coupling region 11 at a large angle, so that the light can be totally reflected and transmitted in the optical waveguide lens after being coupled by the light coupling region 11 . Since the light only needs to be incident in a small angle range, the structural complexity of the front-end optical system can be reduced; at the same time, the transparent lens can also improve the image formed by the out-coupled light from the optical waveguide lens. Happening.

FIG. 3 is a schematic structural diagram of a display device provided by an embodiment of the present application. As shown in FIG. 3 , the display device at least includes: an optical waveguide lens 1 and a transparent lens 2 .

The optical waveguide lens 1 includes a plurality of functional regions, and the plurality of functional regions include a light coupling region 11 . The light coupling region 11 is used for coupling light into the optical waveguide lens and performing total reflection transmission in the optical waveguide lens. The optical waveguide lens 1 may be the optical waveguide lens shown in FIG. 1 .

The transparent lens 2 is attached to the substrate corresponding to the light coupling region 11 in the optical waveguide lens 1 . The light is refracted by the transparent lens 2 and then enters the optical waveguide lens 1 , and is coupled into the optical waveguide lens 1 through the light coupling region 11 for total reflection transmission.

The transparent lens 2 is used to refract the light before it enters the optical waveguide lens, and the refracted light is coupled by the light coupling region 11 to meet the requirement of total reflection transmission in the optical waveguide lens 1 . Optionally, in order to enable the transparent lens 2 to refract the light, the incident angle of the light entering the transparent lens 2 is smaller than the critical angle at which total reflection occurs.

Optionally, the normal of the surface of the transparent lens 2 has multiple angles, so that the light rays of different angles can be refracted through the adapted positions in the transparent lens 2, so that the refracted light is coupled through the light coupling area 11 and meets the requirements. Requirements for total reflection transmission in the optical waveguide lens 1 .

In one example, the transparent lens 2 is a transparent prism attached to the substrate corresponding to the light coupling region 11 . In this case, the transparent prism has at least two side surfaces that are not attached to the optical waveguide sheet, and the normal lines of each side surface are different.

Optionally, the refractive index range of the transparent prism is the same as that of the optical waveguide sheet 1 . In this way, the light refracted by the transparent prism can be directly incident on the optical waveguide sheet 1 without bending, which can reduce the complexity of calculating the incident angle of the light. For example, the refractive index range of a transparent prism is

[1.4, 2].

Optionally, the transparent lens is seamlessly attached to the substrate corresponding to the light coupling region, so as to ensure that the light refracted by the transparent prism can directly enter the optical waveguide lens 1 without bending.

Referring to FIG. 3 , assuming that the light rays are incident at two critical angles that can be totally reflected in the optical waveguide lens 1 (respectively, the light paths shown by the solid lines and the light paths shown by the dotted lines in FIG. 3 ), the sandwich between the two critical angles The angle is 11.3°. After being adjusted by the transparent lens 2 , the angle at which the adjusted light enters the optical waveguide lens becomes larger, and the light is coupled into the optical waveguide lens 2 and satisfies the condition of total reflection transmission. Since the wavelength of the incident light and the period of the periodic nanograting in the light coupling region 11 remain unchanged, the field of view of the light coupled out from the light coupling region 12 remains unchanged at 50°. At this time, due to the refraction effect of the transparent lens, the situation where the image formed by the light coupled out from the light coupling region 12 deviates from the positive angle when the human eye views the image is also improved.

In FIG. 3 , the transparent prism is a triangular prism as an example for illustration. In actual implementation, the transparent prism may also be a quadratic prism, a pentaprism, or the like, and the specific shape of the transparent prism is not limited in this embodiment. In addition, in Figure 3, the angle between the two sides of the triangular prism that is not attached to the optical waveguide lens is taken as an example of 90°. In actual implementation, the angle can also be set to other angles according to the angle of the incident light. It suffices to satisfy the requirement that the adjusted light can be coupled into the optical waveguide lens at an incident angle greater than or equal to the preset angle, and the value of the included angle is not limited in this embodiment.

In another example, the transparent lens 2 is a transparent curved mirror attached to the substrate corresponding to the light coupling region 11 , such as a lens formed by half of a cylinder. Of course, the transparent lens 2 may also be implemented in other shapes, such as irregular shapes, etc. This embodiment does not limit the implementation of the transparent lens 2 .

Optionally, in order to further improve the situation where the image formed by the light coupled out of the light coupling out area 12 deviates from the positive angle when the human eye views the image, another transparent lens may be attached to the substrate corresponding to the light coupling out area 12 .

To sum up, in the display device provided in this embodiment, the transparent lens is attached to the substrate corresponding to the light coupling region of the optical waveguide lens, and the light is refracted by the transparent lens and then enters the optical waveguide lens; at this time, the transparent lens can be Before the light is incident on the light coupling region, the light is received at a small angle of incidence, and the light is refracted to be incident on the light coupling region at a large angle, so that the light can be coupled in the light coupling region after being coupled by the light coupling region. The total reflection transmission is carried out in the waveguide lens; it can solve the limitation of the existing optical waveguide lens, the image viewed by the human eye deviates greatly from the positive angle, and the image display effect is not good; and the demand for a large range of incident light leads to the complex structure of the front-end optical system Since the light only needs to be incident in a small angle range, the structural complexity of the front-end optical system can be reduced; at the same time, the refraction effect of the transparent lens can also improve the image formed by the light coupled out of the optical waveguide lens when the image deviates from the image viewed by the human eye. The positive angle is larger.

Optionally, in another implementation manner, the transparent lens is integrated into the optical waveguide lens. In this case, the optical waveguide lens includes multiple functional areas; the multiple functional areas include light coupling-in areas; The position corresponding to the entry area has a protruding transparent lens; the light is refracted by the transparent lens and then enters the light coupling area, and is coupled into the optical waveguide lens through the light coupling area for total reflection transmission.

At this time, the relevant description of the transparent lens refers to the above-mentioned embodiments, and details are not described herein again in this embodiment.

Optionally, the present application further provides a three-dimensional display system, where the three-dimensional display system is installed with the display device described in the above embodiment; or, the transparent lens described in the above embodiment. Of course, the three-dimensional display system may also include other components, such as: a front-end optical system (such as a projection system), a power supply component, a communication component, etc., which will not be described in detail in this embodiment.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims (10)

1. A display device, characterized in that the display device comprises:

an optical waveguide lens including a plurality of functional regions including a light-in region and a light-out region; when the light rays forming the image are output, the light rays exit the light ray coupling-out area at an angle parallel to the incident light rays; the period of the periodic nanometer grating of the light coupling-in area is consistent with that of the periodic nanometer grating of the light coupling-out area, and at each total reflection emergent point, the light is parallel to the original light;

the transparent lens is attached to the substrate corresponding to the light coupling-in area in the optical waveguide lens so as to weaken the condition that an image formed by coupled light deviates from a positive angle when human eyes watch the image; and light is refracted by the transparent lens, then enters the optical waveguide lens, is coupled into the optical waveguide lens through the light coupling-in area and is transmitted by total reflection.

2. The display device according to claim 1, wherein an incident angle of the light rays incident on the transparent lens is smaller than a critical angle at which total reflection occurs.

3. The display device according to claim 1, wherein the transparent lens is a transparent prism having one surface attached to the substrate corresponding to the light-in coupling area.

4. The display device according to claim 3, wherein the transparent prism has a refractive index range identical to that of the optical waveguide lens.

5. A display device as claimed in claim 4, characterised in that the transparent prism has a refractive index in the range [1.4, 2 ].

6. A display device as claimed in claim 3, characterised in that the transparent prism is a triangular prism.

7. The display device according to any one of claims 1 to 6, wherein the transparent lens is seamlessly attached to the substrate corresponding to the light-in area.

8. The display device according to any one of claims 1 to 6, wherein the plurality of functional areas are located on an upper surface of the optical waveguide lens; or, the lower surface of the optical waveguide lens is positioned; or one part is positioned on the upper surface of the optical waveguide lens, and the other part is positioned on the lower surface of the optical waveguide lens.

9. The display device according to any one of claims 1 to 6, wherein each functional region comprises at least one structural unit pixel, the structural unit pixel being composed of a periodic nanograting.

10. An optical waveguide lens, wherein the optical waveguide lens comprises a plurality of functional areas; the plurality of functional regions include a light-in region and a light-out region; when the light rays forming the image are output, the light rays exit the light ray coupling-out area at an angle parallel to the incident light rays; the period of the periodic nanometer grating in the light coupling-in area is consistent with that of the periodic nanometer grating in the light coupling-out area, and at each total reflection emergent point, the light is parallel to the original light; the position corresponding to the light coupling-in area is provided with a transparent lens which is arranged in a protruding way; the light is refracted by the transparent lens and then enters the light coupling-in area, and is coupled into the optical waveguide lens through the light coupling-in area for total reflection transmission, so that the condition that an image formed by the coupled light deviates from a positive angle when a human eye watches the image is weakened.

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