Optical waveguide device, image output device, image output method and device

Abstract

The present invention provides an optical waveguide device, an image output device, an image output method and a device, wherein the optical waveguide device comprises: a plurality of sequentially arranged light guide elements and a liquid crystal optical device located between two adjacent light guide elements; wherein each liquid crystal optical device comprises a liquid crystal unit and a reflective polarizing film located on the light output side of the liquid crystal unit, and the reflective polarizing film is used to reflect visible light in a first polarization state. The same reflective polarizing film that reflects visible light in a first polarization state is used on the light output side of the liquid crystal units of the plurality of liquid crystal optical devices, so that the plurality of liquid crystal optical devices can ensure the same intensity of the coupled-out light when modulated to appropriate reflectivity and transmittance, thereby solving the problems of yield loss and coating consistency caused by the reflective-transmittance film coating process with extremely high precision requirements in the optical waveguide device in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of optical waveguide technology, and in particular to an optical waveguide device, an image output device, an image output method and a device. Background Art

[0002] With the development of augmented reality technology, AR head-mounted displays, AR glasses, and vehicle-mounted AR-HUD are gradually recognized as the next generation of computing and display platforms, and more and more manufacturers are investing a lot of resources in research and development. The key optical components of AR display devices are the optical machine that generates images and the light transmission module that transmits images to the eyes. Among them, the light transmission module is the most critical part, which directly affects the volume, imaging quality and viewing comfort of AR display devices. In the prior art, geometric optical waveguides have high imaging quality, but the processing procedures are complex and the coating accuracy requirements are extremely high, resulting in low yield and difficulty in increasing the size of the device. The geometric optical waveguide uses multiple out-coupling array units in the light transmission module. The components of the light guide component are plated with a metal film layer with reflection and transmission functions at the connection. In order to ensure the brightness uniformity of the out-coupling light, the coating at each connection is required to have different transmittance and reflectivity. The more out-coupling array units there are, the higher the matching requirements of the coating for reflectivity and transmittance, the more difficult it is to control the process, and the yield loss is very large. Summary of the invention

[0003] The object of the present invention is to provide an optical waveguide device, an image output device, an image output method and a device, which are used to solve the problems of yield loss and coating consistency caused by the reflective and transmissive film coating process with extremely high precision requirements in optical waveguide devices in the prior art.

[0004] In order to solve the above technical problems, an embodiment of the present invention provides an optical waveguide device, which includes:

[0005] A plurality of sequentially arranged light guide elements and a liquid crystal optical device located between two adjacent light guide elements;

[0006] Each of the liquid crystal optical devices comprises a liquid crystal unit and a reflective polarizing film located on the light-emitting side of the liquid crystal unit, and the reflective polarizing film is used to reflect visible light in a first polarization state.

[0007] Optionally, in the optical waveguide device, the liquid crystal unit comprises:

[0008] Two transparent substrates arranged in parallel and a liquid crystal layer located between the two transparent substrates;

[0009] a first electrode layer located between a first transparent substrate of the two transparent substrates and the liquid crystal layer;

[0010] A second electrode layer is located between the second transparent substrate of the two transparent substrates and the liquid crystal layer.

[0011] Optionally, in the optical waveguide device, the light guiding element and the transparent substrate are made of a material having the same optical properties.

[0012] Optionally, in the optical waveguide device, a plurality of the liquid crystal optical devices are respectively arranged in parallel.

[0013] Optionally, in the optical waveguide device, an angle between a light emitting surface of the light guide element and a light emitting surface of the liquid crystal optical device is less than 90 degrees.

[0014] Optionally, the optical waveguide device further comprises:

[0015] The voltage input module is used to input a control voltage to the liquid crystal unit to deflect the liquid crystal molecules of the liquid crystal unit.

[0016] In order to achieve the above object, the present invention also provides an image output device, including an image output module, wherein the device also includes the optical waveguide device as described above, and the light output by the image output module is transmitted to the optical waveguide device to form an out-coupled image.

[0017] Optionally, in the image output device, the image output module comprises:

[0018] An image generation module, including a display screen and an optical path magnifying device;

[0019] A light coupling module located between the optical path amplification device and the optical waveguide device;

[0020] The output image of the display screen passes through the optical path amplifying device to form an amplified image, and the amplified image enters the optical waveguide device through the light coupling module.

[0021] In order to achieve the above object, the present invention further provides an image output method, which is applied to the image output device as described above, and the method comprises:

[0022] Inputting a first control signal to the image output module, so that the image output module generates an image and outputs light in a first polarization state;

[0023] A first voltage signal is input into the liquid crystal unit of the optical waveguide device, so that the liquid crystal in the liquid crystal unit is deflected under the control of the first voltage signal, and the light is subjected to a first angle of optical rotation after passing through the liquid crystal unit to obtain a rotated light, and the rotated light is output as an outcoupled light after passing through a reflective polarizing film of the liquid crystal unit, wherein the rotated light includes a light component in a first polarization state and a light component in a second polarization state whose polarization state is orthogonal to the first polarization state, and the polarization state of the outcoupled light is the first polarization state.

[0024] In order to achieve the above object, the present invention further provides an image output device, wherein the image output device is applied to the above image output device, and the image output device comprises:

[0025] A first output module, used for inputting a first control signal to the image output module, so that the image output module generates an image and outputs light in a first polarization state;

[0026] The second output module is used to input a first voltage signal to the liquid crystal unit of the optical waveguide device, so that the liquid crystal in the liquid crystal unit is deflected under the control of the first voltage signal, and the light passes through the liquid crystal unit and undergoes optical rotation at a first angle to obtain a rotated light. The rotated light passes through the reflective polarizing film of the liquid crystal unit and outputs an outcoupled light, wherein the rotated light includes a light component in a first polarization state and a light component in a second polarization state orthogonal to the first polarization state, and the polarization state of the outcoupled light is the first polarization state.

[0027] The beneficial effects of the above technical solution of the present invention are as follows:

[0028] In the above scheme, the same reflective polarizing film that reflects visible light in the first polarization state is used on the light-emitting side of the liquid crystal units of the multiple liquid crystal optical devices, so that the multiple liquid crystal optical devices can ensure the same intensity of the coupled-out light when modulated to appropriate reflectivity and transmittance, thereby solving the problems of yield loss and coating consistency caused by the reflective-transmittance film coating process with extremely high precision requirements in the optical waveguide device in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of an image output device according to an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of an optical waveguide device according to an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of a liquid crystal optical device of an optical waveguide device according to an embodiment of the present invention;

[0032] Figure 4A schematic diagram of an image output method according to an embodiment of the present invention;

[0033] Figure 5 It is a schematic diagram of an image output device according to an embodiment of the present invention.

[0034] Explanation of symbols:

[0035] 100-image generation module; 101-display screen; 102-optical path amplification device; 200-light coupling module; 301-light guiding element; 302-liquid crystal optical device; 303-liquid crystal unit; 021-reflective polarizing film; 022-first transparent substrate; 023-first electrode layer; 024-liquid crystal layer; 025-second electrode layer; 026-second transparent substrate. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The present invention aims at the problems of yield loss and coating consistency caused by the reflective and transmissive film coating process with extremely high precision requirements in optical waveguide devices in the prior art, and provides an optical waveguide device, an image output device, an image output method and a device.

[0038] like Figures 1 to 3 As shown, an embodiment of the present invention provides an optical waveguide device, which includes:

[0039] A plurality of sequentially arranged light guide elements 301 and a liquid crystal optical device 302 located between two adjacent light guide elements 301;

[0040] Each of the liquid crystal optical devices 302 includes a liquid crystal unit 303 and a reflective polarizing film 021 located on the light-emitting side of the liquid crystal unit 303 , and the reflective polarizing film is used to reflect visible light in a first polarization state.

[0041] In this embodiment, the same reflective polarizing film 021 reflecting visible light of the first polarization state is used on the light-emitting side of the liquid crystal unit 303 of the plurality of liquid crystal optical devices 302, so that the intensity of the coupled-out light is ensured to be the same when the plurality of liquid crystal optical devices 302 are modulated to appropriate reflectivity and transmittance, thereby solving the problems of yield loss and coating consistency caused by the reflective-transmittance film coating process with extremely high precision requirements in the optical waveguide device in the prior art, and can greatly reduce the processing cost of the optical waveguide device and improve the yield rate.

[0042] Optionally, in the optical waveguide device, the liquid crystal unit 303 comprises:

[0043] Two transparent substrates arranged in parallel and a liquid crystal layer 024 located between the two transparent substrates;

[0044] A first electrode layer 023 located between a first transparent substrate 022 of the two transparent substrates and the liquid crystal layer 024;

[0045] The second electrode layer 025 is located between the second transparent substrate 026 of the two transparent substrates and the liquid crystal layer 024 .

[0046] In this embodiment, the liquid crystal unit 303 utilizes the property of liquid crystal that can perform optical rotation modulation on polarized light, and then the reflective polarizing film 021 with polarized light selectivity is set on the light-emitting side of the liquid crystal unit 303. The liquid crystal unit 303 is composed of a liquid crystal layer 024 composed of pre-oriented nematic liquid crystal molecules filled between two transparent substrates. The reflective polarizing film 021 adopts an industry-standard reflective polarizing film, such as 3M's DBEF film, which has been widely used in the backlight module of LCD display screens to increase the light efficiency of the backlight. Figure 3 As shown, the liquid crystal unit 303 further includes the first electrode layer 023 between the first transparent substrate 022 and the liquid crystal layer 024 and the second electrode layer 025 between the second transparent substrate 026 and the liquid crystal layer 024. The liquid crystal molecules in the liquid crystal layer 024 between the first electrode layer 023 and the second electrode layer 025 are arranged from top to bottom with the long axis rotated 90 degrees.

[0047] Optionally, in the optical waveguide device, the light guiding element 301 and the transparent substrate are made of a material having the same optical properties.

[0048] In this embodiment, the light guide element 301 and the transparent substrate are generally made of glass material with the same refractive index, reflectivity and transmittance.

[0049] Optionally, in the optical waveguide device, a plurality of the liquid crystal optical devices 302 are respectively arranged in parallel.

[0050] In this embodiment, in order to ensure that the light emitted from the liquid crystal optical device 302 is parallel and a uniform picture can be formed, a plurality of liquid crystal optical devices 302 are respectively arranged in parallel.

[0051] Optionally, the optical waveguide device is characterized in that an angle between a light emitting surface of the light guide element 301 and a light emitting surface of the liquid crystal optical device 302 is less than 90 degrees.

[0052] In this embodiment, in order to ensure Figure 1 The light from the light emitting surface of the light guide element 301 (for example, the light emitting surface facing the lower side of the figure) can be normally captured by the audience's eyes, and the light emitting surface of the liquid crystal optical device 302 is set less than 90 degrees with the light emitting surface of the light guide element 301.

[0053] Optionally, the optical waveguide device further comprises:

[0054] The voltage input module is used to input a control voltage to the liquid crystal unit 303 to deflect the liquid crystal molecules of the liquid crystal unit 303 .

[0055] In this embodiment, before the voltage input by the voltage input module is less than the threshold voltage, the liquid crystal molecules of the liquid crystal unit 303 are arranged parallel to the transparent substrate. After the voltage exceeds the threshold voltage, the liquid crystal molecules begin to change from being parallel to the transparent substrate to being arranged at a certain angle to the plane where the transparent substrate is located. When the voltage reaches the saturation voltage, the liquid crystal molecules are all perpendicular to the plane where the transparent substrate is located along their own long axis directions. In this process, the polarization state of the light incident on the liquid crystal unit 303 also changes accordingly.

[0056] In order to achieve the above object, the present invention also provides an image output device, including an image output module, wherein the device also includes the optical waveguide device as described above, and the light output by the image output module is transmitted to the optical waveguide device to form an out-coupled image.

[0057] Optionally, in the image output device, the image output module comprises:

[0058] The image generation module 100 includes a display screen 101 and an optical path magnifying device 102;

[0059] A light coupling module 200 located between the optical path amplifying device 102 and the optical waveguide device;

[0060] The output image of the display screen 101 passes through the optical path amplifying device 102 to form an amplified image, and the amplified image enters the optical waveguide device through the light coupling module 200 .

[0061] In this embodiment, the function of the image output module is to collimate and adjust the light emitted by any light-emitting unit on the display screen 101 to obtain collimated parallel light, amplify the image on the display screen 101 through the optical path amplifying device 102, and then introduce the collimated parallel light into the optical waveguide device through the light coupling module 200, wherein the light coupling module 200 is usually flexibly designed according to the light output direction of the image output device and the light entrance structure of the optical waveguide device.

[0062] like Figure 4 To achieve the above object, the present invention further provides an image output method, which is applied to the image output device as described above, and the method comprises:

[0063] Step S10, inputting a first control signal to the image output module, so that the image output module generates an image and outputs light in a first polarization state;

[0064] It should be noted that the light in the first polarization state output by the image output module is the same as the polarization state of the light that can be reflected by the reflective polarizing film 021 .

[0065] Step S20, inputting a first voltage signal to the liquid crystal unit 303 of the optical waveguide device, so that the liquid crystal in the liquid crystal unit 303 is deflected under the control of the first voltage signal, and the light passes through the liquid crystal unit 303 and performs optical rotation at a first angle to obtain a rotated light, and the rotated light passes through the reflective polarizing film 021 of the liquid crystal unit 303 to output an outcoupled light, wherein the rotated light includes a light component in a first polarization state and a light component in a second polarization state whose polarization state is orthogonal to the first polarization state, and the polarization state of the outcoupled light is the first polarization state;

[0066] It should be noted that, if the light in the first polarization state is P light, and the light in the polarization state orthogonal to the first polarization state is S light, the liquid crystal in the liquid crystal unit 303 is deflected under the control of the first voltage signal, for example, the first voltage signal is Va, the liquid crystal molecules form a certain angle α with the plane where the transparent substrate is located along the long axis direction, and the P light passes through the liquid crystal unit 303 and becomes a light with both P light components and S light components. After passing through the reflective polarizing film 021, the P light components are completely reflected, and the S light components are all passed through. The reflected light is the out-coupled light. When the S light component continues to propagate forward and encounters the second liquid crystal optical device 302, a voltage Vb is input to the liquid crystal unit 303 of the second liquid crystal optical device 302, and the liquid crystal molecules form a certain angle β with the plane where the transparent substrate is located along the long axis direction. After passing through, the S light will be converted into a light with both P light components and S light components. After passing through the reflective polarizing film 021, the P light components are completely reflected, and the S light components are all passed through. The reflected light is the out-coupled light. The S light component continues to propagate forward until it encounters the next liquid crystal optical device, and then the above operation is performed. The ratio of the P component to the S component can be controlled by adjusting the first voltage signal, thereby controlling the reflective transmittance of the reflective polarizing film 021 to the light. The first voltage signal of all the liquid crystal optical devices in each of the optical waveguide devices is adjusted to a state where the intensity of the coupled-out light remains consistent, so that a picture with uniform brightness can be obtained.

[0067] It should be noted that the biggest advantage of the embodiment of the present invention is that it can be prepared with a nematic liquid crystal optical rotator (the liquid crystal optical device 302) and a reflective polarizing film material (the reflective polarizing film 021) that are already mass-producible, and each unit does not need to set different reflectivity and transmittance for the reflective polarizing mode, but can dynamically control the reflectivity and transmittance by adjusting the voltage of the liquid crystal optical rotator. It is very beneficial to improve the production yield, and can prepare large-size optical waveguide devices. More importantly, by controlling the voltage of the liquid crystal optical rotator (the first voltage signal), it is also possible to realize the switching of multiple liquid crystal optical devices. If used to make augmented reality glasses, it is possible to achieve state switching between ordinary glasses and augmented reality glasses. The P light and S light components of the incident polarized light are controlled by a liquid crystal optical rotator with a reflective polarizing film, so as to control the intensity of the coupled light to remain the same, so that the brightness of the picture composed of the coupled light is uniform, avoiding the yield loss and coating consistency problems caused by the reflective transmission film coating process with extremely high precision requirements, and can prepare large-size optical waveguide devices.

[0068] like Figure 5As shown, in order to achieve the above-mentioned purpose, the present invention further provides an image output device, wherein, applied to the image output device as described above, the image output device comprises:

[0069] A first output module 51, used for inputting a first control signal to the image output module, so that the image output module generates an image and outputs light in a first polarization state;

[0070] The second output module 52 is used to input a first voltage signal to the liquid crystal unit 303 of the optical waveguide device, so that the liquid crystal in the liquid crystal unit 303 is deflected under the control of the first voltage signal, and the light passes through the liquid crystal unit 303 and undergoes optical rotation at a first angle to obtain a rotated light, and the rotated light passes through the reflective polarizing film 021 of the liquid crystal unit 303 to output an outcoupled light, wherein the rotated light includes a light component in a first polarization state and a light component in a second polarization state whose polarization state is orthogonal to the first polarization state, and the polarization state of the outcoupled light is the first polarization state.

[0071] It should be noted here that the above-mentioned device provided in the embodiment of the present invention can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0072] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An optical waveguide device, characterized in that: include: A plurality of sequentially arranged light guide elements (301) and a liquid crystal optical device (302) located between two adjacent light guide elements (301); Each of the liquid crystal optical devices (302) comprises a liquid crystal unit (303) and a reflective polarizing film (021) located on the light-emitting side of the liquid crystal unit (303), and the reflective polarizing film is used to reflect visible light in a first polarization state.

2. The optical waveguide device according to claim 1, characterized in that The liquid crystal unit (303) comprises: Two transparent substrates arranged in parallel and a liquid crystal layer (024) located between the two transparent substrates; a first electrode layer (023) located between a first transparent substrate (022) of the two transparent substrates and the liquid crystal layer (024); A second electrode layer (025) is located between the second transparent substrate (026) of the two transparent substrates and the liquid crystal layer (024).

3. The optical waveguide device according to claim 2, characterized in that: The light guide element (301) and the transparent substrate are made of materials with the same optical properties.

4. The optical waveguide device according to claim 1, characterized in that The plurality of liquid crystal optical devices (302) are respectively arranged in parallel.

5. The optical waveguide device according to claim 4, characterized in that: The angle between the light emitting surface of the light guide element (301) and the light emitting surface of the liquid crystal optical device (302) is less than 90 degrees.

6. The optical waveguide device according to claim 1, characterized in that Also includes: A voltage input module is used to input a control voltage to the liquid crystal unit (303) so as to cause the liquid crystal molecules of the liquid crystal unit (303) to deflect.

7. An image output device, comprising an image output module, characterized in that: The device further comprises the optical waveguide device as claimed in any one of claims 1 to 6, and the light output by the image output module is transmitted to the optical waveguide device to form an out-coupled image.

8. The image output device according to claim 7, characterized in that: The image output module comprises: An image generation module (100) comprises a display screen (101) and an optical path amplification device (102); A light coupling module (200) located between the optical path amplifying device (102) and the optical waveguide device; The output image of the display screen (101) passes through the optical path amplifying device (102) to form an amplified image, and the amplified image enters the optical waveguide device through the light coupling module (200).

9. An image output method, characterized in that: Applied to the image output device as claimed in claim 7, the method comprises: Inputting a first control signal to the image output module, so that the image output module generates an image and outputs light in a first polarization state; A first voltage signal is input into the liquid crystal unit (303) of the optical waveguide device, so that the liquid crystal in the liquid crystal unit (303) is deflected under the control of the first voltage signal, and the light passes through the liquid crystal unit (303) and undergoes optical rotation at a first angle to obtain rotated light. The rotated light passes through the reflective polarizing film (021) of the liquid crystal unit (303) to output coupled light, wherein the rotated light includes a light component in a first polarization state and a light component in a second polarization state orthogonal to the first polarization state, and the polarization state of the coupled light is the first polarization state.

10. An image output device, characterized in that: Applied to the image output device according to claim 7, the image output device comprising: A first output module, used for inputting a first control signal to the image output module, so that the image output module generates an image and outputs light in a first polarization state; A second output module is used to input a first voltage signal into the liquid crystal unit (303) of the optical waveguide device, so that the liquid crystal in the liquid crystal unit (303) is deflected under the control of the first voltage signal, and the light is subjected to a first angle of rotation after passing through the liquid crystal unit (303) to obtain a rotated light, and the rotated light is output as an outcoupled light after passing through the reflective polarizing film (021) of the liquid crystal unit (303), wherein the rotated light comprises a light component in a first polarization state and a light component in a second polarization state orthogonal to the first polarization state, and the polarization state of the outcoupled light is the first polarization state.

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