Optical waveguide assembly and display device

Abstract

The embodiment of the invention relates to an optical waveguide assembly and a display device. The optical waveguide assembly comprises an optical waveguide substrate; the coupling-in grating is arranged at one end of the optical waveguide substrate, and the coupling-in grating is used for coupling a light beam from an image source into the optical waveguide substrate, so that the light beam is totally reflected in the optical waveguide substrate; the coupling-out grating is arranged at the other end of the optical waveguide substrate, the coupling-out grating is used for coupling light beams out of the optical waveguide substrate, the coupling-out grating comprises a plurality of coupling-out areas, and different coupling-out areas correspond to different coupling-out light beam imaging distances.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of image display technology, and in particular, to an optical waveguide component and a display device. Background Art

[0002] The head-up display (HUD) can project important driving information such as current speed and road navigation onto the windshield in front of the driver, so that the driver can view car-related information without lowering his head while driving, which reduces the safety risks caused by the driver lowering his head to view vehicle information. However, the head-up display in the prior art can usually only form an image on one focal plane, which cannot meet the user's usage needs. Summary of the invention

[0003] Based on this, it is necessary to provide an optical waveguide component and a display device to address the above technical problems.

[0004] In a first aspect, the present application provides an optical waveguide component, comprising:

[0005] Optical waveguide substrate;

[0006] A coupling grating, disposed at one end of the optical waveguide substrate, the coupling grating being used to couple a light beam from an image source into the optical waveguide substrate so that the light beam is totally reflected in the optical waveguide substrate;

[0007] The outcoupling grating is arranged at the other end of the optical waveguide substrate, and is used to couple the light beam out of the optical waveguide substrate. The outcoupling grating includes a plurality of outcoupling regions, and different outcoupling regions correspond to different outcoupling light beam imaging distances.

[0008] In one embodiment, the outcoupling grating is a volume holographic grating, and different outcoupling regions of the volume holographic grating have different grating parameters, and the grating parameters include at least one of a grating constant and a grating depth.

[0009] In one embodiment, the volume holographic grating is made by a double-beam interference exposure process, which includes splitting a light beam provided by an exposure source to form coherent transmitted light and reflected light, and irradiating the transmitted light and the reflected light to a photosensitive film at a preset angle to produce a volume holographic grating including interference fringes.

[0010] In one of the embodiments, a lens is provided on the optical path of at least one of the transmitted light and the reflected light to the photosensitive film;

[0011] Wherein, when the different out-coupling areas in the volume holographic grating are formed by exposure, lenses with different focal lengths are respectively used.

[0012] In one of the embodiments, when exposing to form different out-coupling regions or different sub-regions in the out-coupling region in the volume holographic grating, exposure sources with different emission directions are respectively used.

[0013] In one of the embodiments, when exposing to form different out-coupling regions or different sub-regions in the out-coupling region in the volume holographic grating, exposure sources with different light wavelengths are respectively used.

[0014] In one embodiment, the optical waveguide component includes a plurality of the optical waveguide substrates, each of which is provided with the coupling-in grating and the coupling-out grating, and different optical waveguide substrates are used to transmit light beams of different wavelengths from the image source.

[0015] In a second aspect, the present application provides a display device, including:

[0016] An image source, used for emitting a light beam containing image information;

[0017] An optical waveguide component, the optical waveguide component is the optical waveguide component as described above, and is used to couple the light beam emitted by the image source;

[0018] The display component is used for receiving the outcoupled light beam of the optical waveguide component and reflecting it into human eyes.

[0019] In one of the embodiments, the image source includes a plurality of sub-image sources;

[0020] The emission directions of the plurality of sub-image sources are different; or the light wavelengths of the plurality of sub-image sources are different.

[0021] In one embodiment, the display assembly is a windshield of a vehicle.

[0022] The above-mentioned optical waveguide component and display device, by setting a plurality of outcoupling areas in the outcoupling grating, and adjusting the grating structure in each outcoupling area so that the outcoupling light beam imaging distances corresponding to different outcoupling areas are different, can make the virtual image of the light beam from the image source imaged on different focal planes, so that the user can see the virtual image imaging on different focal planes at different gaze points. Moreover, the imaging method of the optical waveguide component of this embodiment does not affect the human eye's viewing of actual objects, thereby achieving the application of augmented reality head-up display devices. In addition, compared with the method of imaging on different focal planes through lenses of different focal lengths, on the display device using the optical waveguide component of this embodiment, it is not necessary to set a plurality of lenses on the side of the outcoupling grating away from the optical waveguide substrate to achieve a multi-focal effect, thereby reducing the volume of the optical waveguide component. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 Schematic diagram of the imaging field of view and imaging distance of AR-HUD;

[0025] Figure 2 is a schematic structural diagram of an optical waveguide assembly according to an embodiment;

[0026] Figure 3 A schematic diagram of multiple outcoupling regions according to an embodiment;

[0027] Figure 4 The exposure optical path diagram of a volume holographic grating according to an embodiment;

[0028] Figure 5a One of the lenses on the optical path of the reflected light to the photosensitive film of an embodiment;

[0029] Figure 5b A second lens on the optical path of the reflected light to the photosensitive film in an embodiment;

[0030] Figure 6 FIG. 1 is a schematic diagram of the exposure source configuration of an embodiment. Figure 1 ;

[0031] Figure 7 FIG. 1 is a schematic diagram of the exposure source configuration of an embodiment. Figure 2 ;

[0032] Figure 8 is a schematic structural diagram of a display device according to an embodiment;

[0033] Fig. 9 is one of the schematic diagrams of multiple sub-image sources according to an embodiment;

[0034] Fig.10 FIG. 2 is a second schematic diagram of multiple sub-image sources according to an embodiment.

[0035] Component number description:

[0036] Optical waveguide component: 10; optical waveguide substrate: 100; coupling-in grating: 200; coupling-out grating: 300; coupling-out region: 310; image source: 20; sub-image source: 21; exposure source: 30; display component: 40. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] It is understood that the terms "first" and "second" used in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. "Multiple" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined. "Several" means at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0039] Head-up display devices mainly include combined head up display devices (C-HUD), windshield head up display devices (W-HUD) and augmented reality head up display devices (AR-HUD). Among them, Figure 1 This is a schematic diagram of the imaging field of view and imaging distance of AR-HUD, refer to Figure 1 Compared with C-HUD and W-HUD, AR-HUD has a larger imaging field of view and imaging distance, a larger imaging size, and better imaging effect. In addition, in AR-HUD, by combining virtual content with the real environment, display objects such as vehicle information can change position and size following the ever-changing real scenes such as the preceding vehicle, pedestrians, and intersections, thereby achieving more accurate navigation and early warning prompts.

[0040] However, the visual area of ​​a conventional head-up display device is usually a single depth display plane, that is, all images are presented on the same focal plane. Long-term use of a display device with a single focal plane may cause visual fatigue because the user's gaze point cannot be applied to other depths. Moreover, a single focal plane display device is also difficult to meet the user's needs for integrating 3D display images or complex actual images.

[0041] In order to solve the above problems, an embodiment of the present application provides an optical waveguide component that can be used in a display device, such as a head-up display device, and can also be used in smart wearable devices such as augmented reality (AR) glasses and virtual reality (VR) glasses. The embodiment of the present application describes the optical waveguide component for a head-up display device as an example.

[0042] Figure 2FIG. 1 is a schematic diagram of the structure of an optical waveguide assembly 10 according to an embodiment of the present invention. Figure 2 The optical waveguide component 10 includes an optical waveguide substrate 100 , an in-coupling grating 200 and an out-coupling grating 300 .

[0043] The coupling-in grating 200 is disposed at one end of the optical waveguide substrate 100, and is used to couple the light beam from the image source 20 into the optical waveguide substrate 100, so that the light beam is totally reflected in the optical waveguide substrate 100. When the light beam from the image source 20 is incident on the coupling-in grating 200, the diffraction effect of the coupling-in grating 200 can change the propagation direction of the light beam from the image source 20, and make the light beam meet the condition of total reflection transmission in the optical waveguide substrate 100.

[0044] The type of coupling grating 200 can be, but is not limited to, any one of a surface relief grating, a volume holographic grating, and a polarization array waveguide. Surface relief grating (SRG) is a process of "carving" peaks and valleys on the surface of a material through processes such as photolithography and etching, so as to achieve a periodic structure that can meet the required optical performance. Volume holographic grating (VHOE) is a periodic spatial distribution with a refractive index difference formed at the molecular level. Volume holographic gratings usually work under Bragg diffraction conditions. When the light beam meets the Bragg condition, the volume holographic grating will have an extremely high diffraction efficiency. Polarization array waveguides include multiple partially transmissive and partially reflective surfaces, each of which will reflect part of the light out of the waveguide into the human eye, and the remaining light will be transmitted through and continue to move forward in the waveguide. Then this part of the advancing light encounters another mirror surface, repeating the above-mentioned "reflection-transmission" process until the last mirror surface in the mirror array reflects all the remaining light out of the waveguide into the human eye. Preferably, a surface relief grating is used as the coupling-in grating 200, which can be bonded to the surface of the optical waveguide substrate 100 through a thin glass substrate, thus having the advantages of high product yield and suitability for mass production.

[0045] The outcoupling grating 300 is disposed at the other end of the optical waveguide substrate 100 and is used to couple the light beam out of the optical waveguide substrate 100. The outcoupling grating 300 includes a plurality of outcoupling regions 310. Different outcoupling regions 310 correspond to different outcoupling light beam imaging distances.

[0046] Figure 3 is a schematic diagram of multiple coupling-out regions 310 according to an embodiment, referring to Figure 3 , multiple outcoupling regions 310 may be arranged in an array with spacing from each other. For example, Figure 3It is shown that the outcoupling grating 300 includes two outcoupling areas 310, and the two outcoupling areas 310 can be arranged in the longitudinal direction so that the virtual images formed at different imaging distances are arranged in the longitudinal direction. Among them, the grating structures in different outcoupling areas 310 are not completely the same, so that the imaging distances of the outcoupling light beams corresponding to different outcoupling areas 310 are different. The type of the outcoupling grating 300 can be but is not limited to any one of a surface relief grating, a volume holographic grating and a polarization array waveguide, and this embodiment does not limit it. As long as the outcoupling grating 300 includes a plurality of outcoupling areas 310 that can be imaged at different distances, they all fall within the protection scope of this embodiment.

[0047] In the embodiment of the application, by setting a plurality of outcoupling regions 310 in the outcoupling grating 300, and adjusting the grating structure in each outcoupling region 310 so that the outcoupling light beam imaging distances corresponding to different outcoupling regions 310 are different, the virtual image of the light beam from the image source 20 can be imaged on different focal planes, so that the user can see the virtual image imaging on different focal planes at different gaze points. Moreover, the imaging method of the optical waveguide component 10 of the present embodiment does not affect the human eye viewing of real objects, thereby achieving the application of augmented reality head-up display devices. In addition, compared with the method of imaging on different focal planes through lenses of different focal lengths, on the display device using the optical waveguide component 10 of the present embodiment, it is not necessary to set a plurality of lenses on the side of the outcoupling grating 300 away from the optical waveguide substrate 100, so as to achieve a multi-focal effect, thereby reducing the volume of the optical waveguide component 10.

[0048] In one embodiment, the coupling grating 200 includes a plurality of coupling regions with different corresponding grating depths, and the coupling grating 200 is used to expand the light beam from the image source 20 and couple it into the optical waveguide substrate 100. Therefore, the coupling grating 200 also has the function of expanding the pupil, and by dividing the incident light beam into different diffraction orders, each diffraction order propagates in different directions, the field of view of the display device can be effectively increased.

[0049] In one embodiment, the outcoupling grating 300 is a volume holographic grating, and different outcoupling regions 310 of the volume holographic grating have different grating parameters, and the grating parameters include at least one of a grating constant and a grating depth.

[0050] Among them, the grating constant refers to the number of grating lines or grating points contained in a unit length on the grating. The size of the grating constant determines the resolution of the grating. The larger the grating constant, the higher the resolution. It can be understood that the grating parameters can also include a grating period corresponding to the grating constant. The grating period refers to the distance between two adjacent grating lines or grating points. The smaller the grating period, the higher the resolution of the grating, and the higher the grating resolution can be achieved. At the same time, changes in the grating period will also change the diffraction angle, thereby affecting the imaging distance. The grating depth refers to the height or thickness of the grating lines or grating points, which will affect the reflection and transmission characteristics of the grating. A larger grating depth will result in a higher reflectivity, while a smaller grating depth will enhance the transmission effect.

[0051] Specifically, in terms of the grating constant, according to the grating equation, when the light beam is incident vertically on the grating, the size of the diffraction angle depends on the grating constant and the wavelength of the light beam. Different diffraction angles will cause different distributions of the outgoing light in space, which will affect the imaging distance. Therefore, a smaller grating constant will generally result in a larger diffraction angle, which may make the imaging distance farther. In terms of grating depth, a larger grating depth will result in higher reflectivity, while a smaller grating depth will enhance the transmission effect. Since changes in grating depth will affect the optical properties of the grating, the grating depth will also indirectly affect the imaging distance. For example, in order to obtain a longer imaging distance, the grating depth can be adjusted to optimize the reflection and transmission characteristics of the grating.

[0052] In the embodiment of the application, by changing the grating parameters of different outcoupling regions 310 of the outcoupling grating 300, the outcoupling light beam imaging distance corresponding to each outcoupling region 310 can be quantitatively and flexibly adjusted, and the clarity and stability of the imaging can be changed to meet the needs of the user.

[0053] In one embodiment, the volume holographic grating is produced by a dual-beam interference exposure process. Figure 4 FIG. 1 is an exposure optical path diagram of a volume holographic grating according to an embodiment of the present invention. Figure 4 The dual-beam interference exposure process includes splitting the light beam provided by the exposure source 30 to form coherent transmitted light and reflected light, and irradiating the transmitted light and the reflected light to the photosensitive film at a preset angle to generate a volume holographic grating corresponding to the interference fringes.

[0054] The photosensitive film may include at least one of silver halide, dichromate gelatin, photopolymer, and holographic polymer dispersed liquid crystal. Therefore, two coherent light beams interfere with each other inside the photosensitive film to form light and dark interference fringes, so that the refractive index of the photosensitive film changes according to the light and dark of the interference fringes, and finally a volume holographic grating with a periodic refractive index change characteristic is obtained.

[0055] Furthermore, the light beam from the exposure source 30 may first pass through a pinhole, a beam expander, and the first half-wave plate HWP1 before being incident on the beam splitter S, and split into coherent transmitted light and reflected light. The transmitted light passes through the second half-wave plate HWP2, the first attenuator A1, and the first reflector M1 in sequence, and then is incident on the photosensitive film HF at a first angle. The reflected light passes through the second reflector M2 and the second attenuator A2 in sequence, and then is incident on the photosensitive film HF at a second angle. It can be understood that the first attenuator A1 and the second attenuator A2 are used to adjust the intensity of the light passing through, to prevent the light incident on the photosensitive film from being too strong, which affects the quality of the volume holographic grating formed by exposure. Therefore, when the light intensity of the exposure source 30 is appropriate, the first attenuator A1 and the second attenuator A2 may not be required.

[0056] In one embodiment, a lens is provided on the optical path of at least one of the transmitted light and the reflected light to the photosensitive film. Figure 4 A lens is provided on the optical path of the reflected light to the photosensitive film. When different outcoupling areas 310 or different subareas in the outcoupling area 310 are formed in the volume holographic grating by exposure, lenses with different focal lengths can be used respectively. Different subareas in the outcoupling area 310 refer to subareas with different imaging distances of the corresponding outcoupling light beams.

[0057] Taking the case that two outcoupling regions 310 are required in the volume holographic grating as an example, lenses with two focal lengths can be used. Figure 5a The lens of the first focal length shown is arranged on the optical path of the reflected light to the photosensitive film to form a grating structure with a first grating parameter in the first outcoupling region 311. In the second exposure period, Figure 5b The lens of the second focal length is arranged on the optical path of the reflected light to the photosensitive film, so as to form a grating structure with a second grating parameter in the second outcoupling region 312. It should be noted that, Figure 5a and Figure 5b The two lenses shown are only used for exemplary description and are not used to limit the protection scope of this embodiment. Lenses of other shapes may also be used to adjust the reflected light. In addition, the lenses of the above-mentioned multiple focal lengths may also be arranged on the optical path of the transmitted light to the photosensitive film to change the arrangement of the light and dark interference fringes, thereby changing the grating parameters of each out-coupling area 310 of the out-coupling grating 300.

[0058] Figure 6 FIG. 1 is a schematic diagram of the configuration of the exposure source 30 according to an embodiment of the present invention. Figure 1 ,refer to Figure 6In one of the embodiments, when exposing to form different outcoupling areas 310 or different subareas in the outcoupling area 310 in the volume holographic grating, exposure sources 30 with different emission directions are used respectively. Taking the need to set up two outcoupling areas 310 in the volume holographic grating as an example, exposure sources 30 with two emission directions can be used. In the embodiment of the application, exposure is performed in different emission directions without changing the devices on the optical path of the dual-beam interference exposure. It is understandable that changing the devices on the optical path requires re-adjustment and recalibration of the optical path, and the operation is more complicated than changing the exposure source 30. Therefore, the method of this embodiment can reduce the complexity of the process of preparing the volume holographic grating to a certain extent.

[0059] In an exemplary embodiment, the exposure source 30 with two emission directions can be one exposure source 30 irradiating at different angles in different time periods. That is, in the first exposure period, the exposure source 30 is irradiated at different angles. Figure 6 The light is emitted in the obliquely upward direction shown in the upper half, so as to form a grating structure with a first grating parameter in the first outcoupling region 311. In the second exposure period, the exposure source 30 is Figure 6 The lower half shows an obliquely downward direction to emit light, so as to form a grating structure with a second grating parameter in the second outcoupling region 312. The obliquely upward direction may be 45° obliquely upward, and the obliquely downward direction may be 45° obliquely upward. It should be noted that, Figure 6 The two emission directions shown are only used for exemplary description and are not used to limit the protection scope of this embodiment. Other angles may also be used for emission.

[0060] In another exemplary embodiment, the exposure sources 30 with two emission directions can be two exposure sources 30 that irradiate at different angles in the same period of time. Figure 6 The second exposure source is emitted in the oblique upward direction shown in the upper half to form a grating structure with a first grating parameter in the first outcoupling region 311. Figure 6 The lower half shows an obliquely downward direction to emit light, so as to form a grating structure with a second grating parameter in the second outcoupling region 312. The obliquely upward direction may be 45° obliquely upward, and the obliquely downward direction may be 45° obliquely upward. It should be noted that, Figure 6 The two emission directions shown are only for exemplary description and are not used to limit the protection scope of this embodiment, and other angles may also be used for emission. Based on the method of simultaneous exposure by multiple exposure sources 30, the number of exposures can be reduced, thereby improving the preparation efficiency of volume holographic gratings.

[0061] Figure 7 FIG. 1 is a schematic diagram of the configuration of the exposure source 30 according to an embodiment of the present invention. Figure 2 ,refer to Figure 7In one embodiment, when different outcoupling regions 310 in the volume holographic grating are exposed, exposure sources 30 with different light wavelengths are used. In the embodiment of the application, exposure is performed by means of different outgoing light wavelengths without changing the devices on the optical path of the double-beam interference exposure. It is understandable that changing the devices on the optical path requires re-adjustment and calibration of the optical path, and the operation is more complicated than changing the exposure source 30. Therefore, the method of this embodiment can reduce the complexity of the process of preparing the volume holographic grating to a certain extent.

[0062] Exemplarily, the exposure source 30 of two light wavelengths can be a white exposure source 30 irradiated by filters of different colors at different time periods. That is, in the first exposure period, the exposure source 30 is irradiated by a filter of the first color to form a grating structure with a first grating parameter in the first outcoupling area 311. In the second exposure period, the exposure source 30 is irradiated by a filter of the second color to form a grating structure with a second grating parameter in the second outcoupling area 312. The first color can be green, and the second color can be blue. It should be noted that the above two colors of filters are only used for exemplary description, and are not used to limit the protection scope of this embodiment, and filters of other colors may also be used.

[0063] In another exemplary embodiment, the exposure source 30 of two light wavelengths may be two exposure sources 30 of different colors that are irradiated separately in the same period of time. That is, the exposure source 30 of the first color and the exposure source 30 of the second color are irradiated simultaneously to form a grating structure with a first grating parameter in the first outcoupling area 311, and to form a grating structure with a second grating parameter in the second outcoupling area 312. The first color may be green, and the second color may be blue. It should be noted that the above two colors are only used for exemplary description, and are not used to limit the protection scope of this embodiment, and exposure sources 30 of other colors may also be used. Based on the method of simultaneously exposing multiple exposure sources 30, the number of exposures can be reduced, thereby improving the preparation efficiency of the volume holographic grating.

[0064] In one embodiment, the optical waveguide assembly 10 includes a plurality of optical waveguide substrates 100, each of which is provided with an in-coupling grating 200 and an out-coupling grating 300, and different optical waveguide substrates 100 are used to transmit light beams of different wavelengths from the image source 20. The plurality of optical waveguide substrates 100 may be arranged sequentially along the same direction in the same plane, or may be arranged in an array in the same plane, or may be stacked, which is not limited in this embodiment. As long as there is no mutual obstruction between the plurality of optical waveguide substrates 100 and imaging can be performed at a required distance, they all fall within the protection scope of this embodiment. Specifically, in addition to regional light splitting, the use of multiple optical waveguide substrates 100 may also use different light wavelengths for optical waveguide exposure, so that when different light sources are incident on the optical waveguide, images with different wavelengths may be emitted, thereby achieving full-color display.

[0065] Figure 8 is a schematic diagram of the structure of a display device according to an embodiment, referring to Figure 8 The display device includes an image source 20, an optical waveguide component 10 and a display component 40.

[0066] The image source 20 is used to emit a light beam containing image information. The image source 20 may include a monochromatic light source, such as a white light source. The optical waveguide component 10 is the optical waveguide component 10 described above, and is used to couple in the light beam emitted by the image source 20. The display component 40 is used to receive the outcoupled light beam of the optical waveguide component 10 and reflect it into the human eye.

[0067] Based on the aforementioned optical waveguide component 10, the display device of this embodiment can image the virtual image of the light beam from the image source 20 on different focal planes, so that the user can see the virtual image at different focal planes at different gaze points. Moreover, the imaging method of the display device of this embodiment does not affect the human eye's viewing of real objects, thereby achieving the application of augmented reality head-up display devices. In addition, compared with the method of imaging on different focal planes through lenses of different focal lengths, on the display device of this embodiment, it is not necessary to set multiple lenses on the side of the outcoupling grating 300 away from the optical waveguide substrate 100 to achieve a multi-focal effect, thereby reducing the volume occupied by the optical waveguide component 10 in the display device.

[0068] In one embodiment, the display device further includes an optical system for collimating the light beam emitted by the image source 20 and transmitting it to the optical waveguide component 10 , so that the light beam can be vertically incident on the optical waveguide component 10 , thereby improving the transmission quality of the optical waveguide component 10 .

[0069] In one embodiment, the image source 20 includes a plurality of sub-image sources 21. Fig. 9 , the emission directions of the multiple sub-image sources 21 are different. Fig.10, the wavelengths of light of the multiple sub-image sources 21 are different. By increasing the number of light sources in the image source 20, richer images can be displayed, and the display device can be applied to more complex usage scenarios. It should be noted that in order to simplify the drawings, the display component 40 in the figure is omitted.

[0070] In one embodiment, the display assembly 40 is a windshield of a vehicle.

[0071] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above embodiments only express several implementation methods of the embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the embodiments of the present application, and these all belong to the protection scope of the embodiments of the present application. Therefore, the protection scope of the patent of the embodiments of the present application shall be subject to the attached claims.

Claims

1. An optical waveguide component, characterized in that: include: Optical waveguide substrate; A coupling grating, disposed at one end of the optical waveguide substrate, the coupling grating being used to couple a light beam from an image source into the optical waveguide substrate so that the light beam is totally reflected in the optical waveguide substrate; The outcoupling grating is arranged at the other end of the optical waveguide substrate, and is used to couple the light beam out of the optical waveguide substrate. The outcoupling grating includes a plurality of outcoupling regions, and different outcoupling regions correspond to different outcoupling light beam imaging distances.

2. The optical waveguide assembly according to claim 1, characterized in that The out-coupling grating is a volume holographic grating, and different out-coupling regions of the volume holographic grating have different grating parameters, and the grating parameters include at least one of a grating constant and a grating depth.

3. The optical waveguide assembly according to claim 2, characterized in that The volume holographic grating is made by a double-beam interference exposure process, which includes splitting a light beam provided by an exposure source to form coherent transmitted light and reflected light, and irradiating the transmitted light and the reflected light to a photosensitive film at a preset angle to generate a volume holographic grating including interference fringes.

4. The optical waveguide assembly according to claim 3, characterized in that A lens is provided on the optical path of at least one of the transmitted light and the reflected light to the photosensitive film; Wherein, when the different out-coupling areas in the volume holographic grating are formed by exposure, lenses with different focal lengths are respectively used.

5. The optical waveguide assembly according to claim 3, characterized in that When the different out-coupling areas or different subareas in the out-coupling areas in the volume holographic grating are formed by exposure, the exposure sources with different emitting directions are respectively used.

6. The optical waveguide assembly according to claim 3, characterized in that When exposing to form different out-coupling regions or different sub-regions in the out-coupling region in the volume holographic grating, exposure sources with different light wavelengths are respectively used.

7. The optical waveguide component according to any one of claims 1 to 6, characterized in that: The optical waveguide assembly includes a plurality of the optical waveguide substrates, each of which is provided with the coupling-in grating and the coupling-out grating respectively, and different optical waveguide substrates are used to transmit light beams of different wavelengths from the image source respectively.

8. A display device, characterized in that: include: An image source, used for emitting a light beam containing image information; An optical waveguide component, the optical waveguide component being the optical waveguide component according to any one of claims 1 to 7, used for coupling into the light beam emitted by the image source; The display component is used for receiving the outcoupled light beam of the optical waveguide component and reflecting it into human eyes.

9. The display device according to claim 8, characterized in that: The image source includes a plurality of sub-image sources; The emission directions of the plurality of sub-image sources are different; or the light wavelengths of the plurality of sub-image sources are different.

10. The display device according to claim 8, characterized in that: The display assembly is a windshield of a vehicle.

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