CN215813552U - Optical waveguide system and display device - Google Patents

Abstract

The utility model provides an optical waveguide system and a display device. An optical waveguide system comprising: a light source assembly; the optical waveguide sheet is arranged at intervals with the light source component and is used for receiving image light emitted by the light source component; the coupling-in grating is arranged on the optical waveguide sheet and is used for coupling the image light into the optical waveguide sheet; the coupling-out grating is arranged on the optical waveguide sheet and is positioned on the surface of the same side of the optical waveguide sheet as the coupling-in grating, the coupling-out grating is used for receiving image light of the coupling-in grating, and the coupling-out grating is used for coupling the image light out of the optical waveguide sheet; the two-dimensional angle adjusting structure is one or more, and at least one of the coupling-in path of the coupling-in grating and the light-emitting path of the coupling-out grating is provided with the two-dimensional angle adjusting structure. The utility model solves the problem of small field angle of the optical waveguide system in the prior art.

Description

Optical waveguide system and display device

Technical Field

The utility model relates to the technical field of optical imaging equipment, in particular to an optical waveguide system and a display device.

Background

With the development of science and technology, Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR) have gradually come into the lives of people, wherein in the AR aspect, optical waveguide technology is an indispensable step, and since light is transmitted in an optical waveguide to satisfy a total reflection condition, an angle range capable of being transmitted is limited. The design of optical waveguides therefore also has inherent disadvantages: for the light source component, light emitted by each pixel point of the light source component is collimated and then enters the optical waveguide sheet in a parallel light mode with a certain angle through coupling in the optical grating. Due to the limited size of each pixel point of the light source component, the geometric size of the micro display needs to be increased in order to improve the image resolution. However, when the number of pixels is increased, since the range of angles in which the grating can be coupled into the optical waveguide sheet is fixed, the distance between the microdisplay and the collimating mirror needs to be increased, which will undoubtedly increase the geometric dimension of the light source module, and therefore there is a mutual constraint relationship between the resolution enhancement and the geometric dimension of the light source module. Second, the FOV (field of view) is small, the FOV of the system is mainly limited by the material of the optical waveguide sheet, and in order to increase the FOV of the system, an optical waveguide sheet material with a higher refractive index is mostly selected, but the material with a higher refractive index has lower transmittance, and the weight and price are increased accordingly, and the increase degree is limited, and the problem of small FOV cannot be completely solved.

That is, the optical waveguide system in the related art has a problem of a small angle of view.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims to provide an optical waveguide system and a display device, which solve the problem that the optical waveguide system in the prior art has a small angle of view.

In order to achieve the above object, according to one aspect of the present invention, there is provided an optical waveguide system comprising: a light source assembly; the optical waveguide sheet is arranged at intervals with the light source component and is used for receiving image light emitted by the light source component; the coupling-in grating is arranged on the optical waveguide sheet and is used for coupling the image light into the optical waveguide sheet; the coupling-out grating is arranged on the optical waveguide sheet and is positioned on the surface of the same side of the optical waveguide sheet as the coupling-in grating, the coupling-out grating is used for receiving image light of the coupling-in grating, and the coupling-out grating couples the image light out of the optical waveguide sheet; the two-dimensional angle adjusting structure is one or more, and at least one of the coupling-in path of the coupling-in grating and the light-emitting path of the coupling-out grating is provided with the two-dimensional angle adjusting structure.

Further, when the two-dimensional angle adjusting structure is one, the two-dimensional angle adjusting structure is arranged on an incoupling path of the incoupling grating or an outcoming path of the incoupling grating; when the two-dimensional angle adjusting structures are multiple, the two-dimensional angle adjusting structures are respectively arranged on the coupling-in path of the coupling-in grating and the light-emitting path of the coupling-out grating.

Furthermore, the two-dimensional angle adjusting structure is a two-dimensional angle amplifier, and the two-dimensional angle amplifier on the coupling-in path of the coupling-in grating and the two-dimensional angle amplifier on the light-emitting path of the coupling-out grating are arranged in opposite directions.

Furthermore, the two-dimensional angle adjusting structure comprises a plurality of volume Bragg grating layers, wherein the volume Bragg grating layers are arranged in a stacked mode, and grating vector surfaces of at least two volume Bragg grating layers in the plurality of volume Bragg grating layers are arranged in an angle mode.

Furthermore, the grating vector planes of at least partial two adjacent layers of the multilayer volume Bragg grating layers are vertical to each other.

Further, the material of the volume Bragg grating layer is one of PTR glass, liquid crystal and photosensitive resin material.

Further, the two-dimensional angle adjusting structure is one of a liquid crystal optical phased array, a liquid crystal polarization grating and a cascade optical phased array.

Further, the light source assembly comprises: a micro display for emitting image light; the collimating mirror is used for collimating the image light emitted by the micro display; wherein, the micro display is one of OLED, MicroLED, LBS, LCOS and LED.

Furthermore, the optical waveguide system further comprises a turning grating, the turning grating is arranged on the optical waveguide sheet and is positioned on the same side surface of the optical waveguide sheet as the coupling grating, the turning grating is used for receiving the image light of the coupling grating, and the coupling grating is used for receiving the image light of the turning grating.

According to another aspect of the present invention, there is provided a display device comprising the optical waveguide system described above.

By applying the technical scheme of the utility model, the optical waveguide system comprises a light source component, an optical waveguide sheet, an incoupling grating, an outcoupling grating and a two-dimensional angle adjusting structure, wherein the optical waveguide sheet and the light source component are arranged at intervals, and the optical waveguide sheet is used for receiving image light emitted by the light source component; the coupling grating is arranged on the optical waveguide sheet and is used for coupling image light into the optical waveguide sheet; the coupling-out grating is arranged on the optical waveguide sheet and is positioned on the surface of the same side of the optical waveguide sheet as the coupling-in grating, the coupling-out grating is used for receiving image light of the coupling-in grating, and the coupling-out grating couples the image light out of the optical waveguide sheet; the two-dimensional angle adjusting structure is one or more, and at least one of the coupling-in path of the coupling-in grating and the light-out path of the coupling-out grating is provided with the two-dimensional angle adjusting structure.

The optical waveguide sheet and the light source component are arranged at intervals, and the coupling grating is arranged on the optical waveguide sheet so that the light source component can emit image light to the optical waveguide sheet, and further the coupling grating on the optical waveguide sheet can couple most of the image light emitted by the light source component into the optical waveguide sheet so as to ensure the coupling efficiency of the optical waveguide sheet. The coupling grating is arranged on the optical waveguide sheet and is positioned on the same side surface of the optical waveguide sheet as the coupling grating, and the coupling grating is used for receiving image light of the coupling grating, so that most effective image light coupled into the optical waveguide sheet by the coupling grating can enter the coupling grating, the coupling grating can couple the image light out of the optical waveguide sheet, most light coupled out by the coupling grating can enter human eyes for imaging, and the imaging stability of the optical waveguide sheet is ensured. The two-dimensional angle adjusting structure can play a role in adjusting the angle of the image light, when the two-dimensional angle adjusting structure is arranged on the coupling-in path of the coupling-in grating, the angle of the image light emitted by the light source component before the image light is coupled into the light guide plate is reduced to a certain degree, so that the coupling-in of the image light is increased, the transmission angle of the image light in the light guide plate is increased, the display resolution of the light guide system is increased, and the loss of an imaging picture is avoided; when the two-dimensional angle adjusting structure is arranged on the light-emitting path of the coupling-out grating, the two-dimensional angle adjusting structure can increase the emergent angle of the coupling-out light, so that the coupling-out amplification effect is realized, the image seen by a user is amplified, and the use satisfaction of the user is improved.

In addition, by arranging the two-dimensional angle adjusting structure, the whole system does not need to increase the material refractive index of the optical waveguide sheet, and the low cost is ensured; and the optical waveguide system with high resolution and large FOV can be obtained without increasing the size of the light source component, and the neck problem that the FOV of the optical waveguide system is too small can be improved. Meanwhile, the space between each device in the optical waveguide system can be planned to ensure the miniaturization of the optical waveguide system.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the utility model and, together with the description, serve to explain the utility model and not to limit the utility model. In the drawings:

FIG. 1 illustrates a schematic imaging light path of a prior art in-vehicle heads-up display;

fig. 2 is a schematic structural diagram of an optical waveguide system according to a first embodiment of the present invention;

FIG. 3 is a schematic diagram showing the light transmission of an optical waveguide system without a two-dimensional angular adjustment structure;

FIG. 4 is a schematic view of another angle of the optical waveguide system of FIG. 3;

FIG. 5 shows a light transmission diagram of the light guide system of FIG. 2;

FIG. 6 is a schematic diagram of light transmission of a volume Bragg grating layer in a two-dimensional angular adjustment structure;

FIG. 7 shows a Bragg relationship diagram for the volume Bragg grating of FIG. 6;

FIG. 8 shows a process diagram for fabricating a volume Bragg grating layer;

FIG. 9 is a schematic diagram of light transmission of a two-dimensional angular adjustment structure;

fig. 10 is a schematic structural view showing an optical waveguide system according to a second embodiment of the present invention;

fig. 11 is a schematic structural diagram of an optical waveguide system according to a third embodiment of the present invention.

Wherein the figures include the following reference numerals:

10. a light source assembly; 11. a microdisplay; 12. a collimating mirror; 20. an optical waveguide sheet; 30. coupling in a grating; 40. coupling out the grating; 50. a two-dimensional angle adjustment structure; 51. a volume Bragg grating layer; 60. a windshield.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present invention, unless specified to the contrary, use of the terms of orientation such as "upper, lower, top, bottom" or the like, generally refer to the orientation as shown in the drawings, or to the component itself in a vertical, perpendicular, or gravitational orientation; likewise, for ease of understanding and description, "inner and outer" refer to the inner and outer relative to the profile of the components themselves, but the above directional words are not intended to limit the utility model.

The utility model provides an optical waveguide system and a display device, aiming at solving the problem that the optical waveguide system in the prior art has a small field angle.

As shown in fig. 1 to 11, the optical waveguide system includes a light source assembly 10, an optical waveguide sheet 20, an incoupling grating 30, an outcoupling grating 40, and a two-dimensional angle adjusting structure 50, wherein the optical waveguide sheet 20 is disposed at an interval from the light source assembly 10, and the optical waveguide sheet 20 is used for receiving image light emitted by the light source assembly 10; the incoupling grating 30 is disposed on the optical waveguide sheet 20, and the incoupling grating 30 serves to couple image light into the optical waveguide sheet 20; the coupling-out grating 40 is disposed on the optical waveguide sheet 20 and located on the same side surface of the optical waveguide sheet 20 as the coupling-in grating 30, the coupling-out grating 40 is configured to receive image light coupled into the coupling-in grating 30, and the coupling-out grating 40 couples the image light out of the optical waveguide sheet 20; the two-dimensional angle adjustment structure 50 is one or more, and the two-dimensional angle adjustment structure 50 is disposed on at least one of the coupling-in path of the coupling-in grating 30 and the coupling-out path of the coupling-out grating 40.

The optical waveguide sheet 20 and the light source assembly 10 are disposed at an interval, and the coupling grating 30 is disposed on the optical waveguide sheet 20, so that the light source assembly 10 can emit image light to the optical waveguide sheet 20, and further the coupling grating 30 on the optical waveguide sheet 20 can couple most of the image light emitted by the light source assembly 10 into the optical waveguide sheet 20, so as to ensure the coupling efficiency of the optical waveguide sheet 20. The coupling-out grating 40 is disposed on the optical waveguide sheet 20 and located on the same side surface of the optical waveguide sheet 20 as the coupling-in grating 30, the coupling-out grating 40 is configured to receive image light coupled into the optical waveguide sheet 30, so that effective image light coupled into the optical waveguide sheet 20 by the coupling-in grating 30 can be mostly incident into the coupling-out grating 40, and further the coupling-out grating 40 couples the image light out of the optical waveguide sheet 20, so that most of light coupled out by the coupling-out grating 40 can enter human eyes for imaging, thereby ensuring the imaging stability of the optical waveguide sheet 20. By arranging the two-dimensional angle adjusting structure 50, the two-dimensional angle adjusting structure 50 can play a role in adjusting the angle of the image light, when the two-dimensional angle adjusting structure 50 is arranged on the coupling path of the coupling grating 30, the angle of the image light emitted by the light source assembly 10 before being coupled into the light guide plate 20 is reduced to a certain extent, so that the coupling of the image light is increased, meanwhile, the transmission angle of the image light in the light guide plate 20 is increased, the display resolution of the light guide system is increased, and meanwhile, the loss of an imaging picture is avoided; when the two-dimensional angle adjusting structure 50 is disposed on the light-emitting path of the coupling-out grating 40, the two-dimensional angle adjusting structure 50 can increase the exit angle of the coupled-out light, thereby achieving the coupling-out amplification effect, so that the image viewed by the user is amplified, and the use satisfaction of the user is improved.

In addition, the two-dimensional angle adjusting structure 50 is arranged, so that the refractive index of the material of the optical waveguide sheet 20 does not need to be increased in the whole system, and low cost is ensured; and the optical waveguide system with high resolution and large FOV can be obtained without increasing the size of the light source assembly 10, which is beneficial to improving the neck problem that the FOV of the optical waveguide system is too small. Meanwhile, the space between each device in the optical waveguide system can be planned to ensure the miniaturization of the optical waveguide system.

As shown in fig. 2, the light source assembly 10 includes a microdisplay 11 and a collimating mirror 12, the microdisplay 11 emitting image light, and the collimating mirror 12 collimating the image light emitted from the microdisplay 11. The microdisplay 11 is placed in the focal plane of the collimating lens. The microdisplay 11 is made up of a plurality of pixels, each of which is capable of independently emitting light.

As shown in fig. 3, an optical waveguide system is provided without the two-dimensional angle adjustment structure 50. Here we only take three special pixels on the microdisplay 11 as the analysis, and the light emitted by each pixel is a cluster of light containing many angles of light, and for simplicity, only one special light is shown in the figure. Three light rays are emitted by the microdisplay 11 in the figure. These three rays are collimated by the collimator lens 12 and impinge on the incoupling grating 30 at an angle. The coupled grating 30 diffracts the three light rays into three light rays satisfying the total reflection condition through diffraction, and in the figure, the light rays in the optical waveguide sheet 20 are first-order diffracted light rays of each light ray diffracted by the coupled grating 30, and the light rays can propagate in the optical waveguide sheet 20.

As shown in fig. 4, an optical waveguide system without the two-dimensional angle adjustment structure 50 is shown. The specific diffraction process is shown in fig. 4, only one pixel point on the right side of the microdisplay 11 is taken for specific analysis, a cluster of light emitted by the microdisplay 11 is collimated by the collimating mirror 12, the originally divergent light beam is changed into parallel light with only one angle, and when the parallel light is diffracted into the optical waveguide sheet 20 through the coupling grating 30, first-order diffraction light and zero-order diffraction light can be generated, wherein the first-order diffraction light is light transmitted to the right in the optical waveguide sheet 20 in the figure, and the zero-order diffraction light is light transmitted to the left. Through reasonable design, the first-order diffracted light with high energy and diffraction angle satisfying the total reflection condition can be transmitted in the optical waveguide sheet 20, and the zero-order diffracted light as stray light overflows the optical waveguide sheet 20 because the total reflection condition is not satisfied.

Specifically, the micro display 11 is one of an OLED, a micro LED, an LBS, an LCOS, and an LED. But not limited to the above, and may be selected according to the actual situation.

The collimator lens 12 is a biconvex lens.

It should be noted that, the microdisplay 11 in the present application may be larger in size, and the two-dimensional angle adjusting structure 50 is arranged to ensure that light of the microdisplay 11 can be coupled into the optical waveguide sheet 20, so that light of the microdisplay 11 with larger size and containing more pixels can be transmitted to human eyes through the optical waveguide sheet 20. From the aspect of image quality, the resolution of the eye catcher to the image can be effectively improved. It is possible to adapt a larger size microdisplay 11 to improve system resolution without changing the longitudinal dimension of the optical assembly.

Example one

As shown in fig. 1 to 10, when there is one two-dimensional angle adjusting structure 50, the two-dimensional angle adjusting structure 50 is disposed on the coupling-in path of the coupling-in grating 30. Specifically, the two-dimensional angle adjustment structure 50 is a two-dimensional angle amplifier.

Specifically, there are many diffraction devices capable of achieving angle amplification, including super-surface diffraction optical elements, holographic diffraction elements, and related cascade combinations. The two-dimensional angle amplifier is one of an optical phased array, a liquid crystal polarization grating and a cascade optical phased array. Of course, the method is not limited to the above type, and the method can be set according to actual conditions. The two-dimensional angle amplifier can realize continuous deflection of angles in the horizontal direction and the vertical two-dimensional direction within +/-45 degrees or +/-60 degrees or other two-dimensional angle ranges, and light in a certain angle range is amplified on a two-dimensional scale.

The two-dimensional angle amplifiers are generally called, and the optical path is reversible, so that the forward and reverse operations can realize the angle enlargement or reduction of the light beam.

As shown in fig. 9, the two-dimensional angle adjustment structure 50 includes a volume bragg grating layer 51, the volume bragg grating layer 51 is a plurality of layers, the plurality of layers of volume bragg grating layers 51 are stacked, and grating vector surfaces of at least two layers of volume bragg grating layers 51 in the plurality of layers of volume bragg grating layers 51 are arranged at an angle. The volume bragg grating layer 51 includes a plurality of volume bragg gratings, and two-dimensional channels are multiplexed on the recording material by a single-layer multi-channel multiplexing or two-layer multi-channel multiplexing method, where the number of the channels may be 32 channels, 64 channels, or 1000 channels and 2000 channels or more. Specifically, the grating vector planes of at least some adjacent two layers of the multi-layer bulk bragg grating layer 51 are perpendicular to each other.

Volume bragg gratings are widely used in various optical systems due to their advantages of high angular selectivity, high efficiency, and the like. Fig. 6 illustrates the working principle of the volume bragg grating, after incident light enters the volume bragg grating, because there is a bragg grating structure with a periodically changing refractive index inside the grating, the diffraction characteristics need to satisfy the bragg relationship diagram in fig. 7, and the emergent light in fig. 6 satisfies the bragg condition and is efficiently emitted. The modulation in a larger angle range can be realized by reasonably designing parameters such as the period, the inclination angle and the like of the volume Bragg grating, and the advantages of high angle selectivity, high efficiency and the like exist, and the volume Bragg grating can be used as an angle amplifier in a multiplexing mode. Wherein

The grating vector of the volume bragg grating.

The volume bragg grating is manufactured by an interference exposure method. Fig. 8 briefly describes the method of making the volume bragg grating layer 51. Two recording lights are incident into the volume bragg grating layer 51 at an angle. The two incident lights can be generated by dividing the laser light source with stronger coherence into two lights through the beam splitter in a classical amplitude division mode, and can also be generated in a wave division front mode, and no specific requirement is made here. Adjusting the appropriate angle as shown in the left side of fig. 8, the bragg grating is recorded in the volume bragg grating layer 51, and the second recording is performed by rotating the volume bragg grating layer 51 by 180 degrees. In this way a set of volume bragg gratings symmetric about 0 ° can be recorded without adjusting the light source assembly 10. The above-mentioned rotary recording process is repeated to perform multiplex recording by continuously adjusting the angles of the two recording lights. Because the grating vector of the volume Bragg grating always rotates in one plane, the method can only manufacture a one-dimensional angle expander. As shown in fig. 9, two layers of volume bragg grating layers 51 with mutually perpendicular grating vector surfaces are used for the two-dimensional angle expansion. Of course, the method can also be implemented by stacking the plurality of volumetric bragg grating layers 51 with the light vector planes at a certain angle.

As shown in fig. 9, a two-dimensional angle expansion effect is achieved by superimposing two volume bragg grating layers 51, which are multiplexed and recorded and have grating vector surfaces perpendicular to each other. As can be seen from the figure, the angle of the light ray on the left side of the two-dimensional angle adjusting structure 50 is enlarged after passing through the two-dimensional angle adjusting structure 50. Since the two-dimensional angle adjustment structure 50 is a two-dimensional device, it can be implemented within a certain two-dimensional angle range such as: the light rays are continuously deflected within the angle range of +/-45 degrees or +/-60 degrees.

As shown in fig. 5, taking the rightmost pixel point in the microdisplay 11 as an example, a cluster of light emitted from the pixel point is collimated by the collimating mirror 12 and then converted into a cluster of parallel light with a certain angle, and the cluster of parallel light is diffracted by the two-dimensional angle adjusting structure 50 and then emitted as a cluster of parallel light with a smaller angle, and then the light is coupled into the light guiding sheet 20 by the in-coupling grating 30.

Specifically, the material of the volume bragg grating layer 51 is PTR glass, that is, photothermographic glass. But of course may be a liquid crystal or a photosensitive resin material. Other holographic recording materials are possible, but not limited thereto. The selection can be made according to actual conditions.

Specifically, the optical waveguide system further includes a turning grating disposed on the optical waveguide sheet 20 and located on the same side surface of the optical waveguide sheet 20 as the coupling grating 30, the turning grating is configured to receive the image light coupled into the turning grating 30 and perform pupil expanding transmission, and the coupling grating 40 is configured to receive the image light of the turning grating and optically couple the image light out to human eyes.

It should be noted that the coupling-in grating 30, the turning grating and the coupling-out grating 40 are diffraction gratings, and may also include, but are not limited to, micro-nano optical structures such as super-surface structure elements, one-dimensional relief gratings, two-dimensional gratings, holographic bragg gratings, and the like.

It should be noted that the turning grating can be disposed independently, or can be designed integrally with the coupling-out grating 40. When the turning grating and the coupling grating 40 are designed as a whole, the coupling grating 30 couples the light emitted from the light source assembly 10 into the light-coupling waveguide sheet 20, and then the light is transmitted to the coupling grating 40 through total reflection, and the coupling grating 40 directly expands the pupil and couples the light-coupling waveguide sheet 20.

The display device comprises the optical waveguide system.

The display device may be an in-vehicle head-up display or AR glasses.

As shown in fig. 1, when the display device is a vehicle head-up display, the image light coupled out by the optical waveguide system is not directly transmitted to the human eye, but is coupled out to the front windshield 60 and reflected by the windshield 60 into the human eye for imaging. Through the form, a person can see the real scene outside the vehicle in the driving process and simultaneously receive signals generated by the optical waveguide system, such as navigation information, speed per hour, oil quantity and the like.

Example two

The difference from the first embodiment is that the two-dimensional angle adjusting structure 50 is disposed at a different position and in a different direction.

As shown in fig. 10, a two-dimensional angular adjustment structure 50 is arranged in the light exit path of the outcoupling grating 40. And the two-dimensional angle adjusting structure 50 on the light-emitting path is placed in the opposite direction to the two-dimensional angle adjusting structure 50 in the first embodiment. To ensure the amplification of the two-dimensional angular adjustment structure 50 in the light exit path. The two-dimensional angle adjusting structure 50 can increase the outgoing angle of the coupled light, so that the coupled light amplifying effect is achieved, and the angle amplifying effect on the coupled image is achieved, so that the image seen by the user is amplified, and the use satisfaction of the user is improved.

EXAMPLE III

The difference from the first and second embodiments is that the number of the two-dimensional angle adjustment structures 50 is different.

As shown in fig. 11, when there are a plurality of two-dimensional angle-adjusting structures 50, two-dimensional angle-adjusting structures 50 are respectively disposed on the coupling-in path of the coupling-in grating 30 and the coupling-out path of the coupling-out grating 40. The two-dimensional angle enlargers on the coupling-in path of the coupling-in grating 30 are placed in the opposite direction to the two-dimensional angle enlargers on the coupling-out path of the coupling-out grating 40. Two-dimensional angle adjustment structures 50 having the same structure are disposed in a reverse-to-forward manner and respectively disposed between the coupling grating 30 of the optical waveguide sheet 20 and the light source assembly 10 and at the coupling-out position of the optical waveguide sheet 20. The two-dimensional angle adjusting structure 50 before coupling in can reduce the angle of the image light with a larger angle emitted from the light source assembly 10 and couple the image light into the optical waveguide sheet 20 by the coupling grating 30, and the two-dimensional angle adjusting structure 50 after coupling out can amplify and restore the angle of the coupled-out image light to realize the effect of reducing coupling in and coupling out and amplifying the image light, so that the limitation of the transmission FOV of the optical waveguide system can be broken, on the basis of not changing the material of the optical waveguide sheet 20, the whole system can realize a larger FOV, and the transmittable FOV of the whole optical waveguide system is improved.

It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. An optical waveguide system, comprising:

a light source assembly (10);

the light guide sheet (20), the light guide sheet (20) and the light source component (10) are arranged at intervals, and the light guide sheet (20) is used for receiving the image light emitted by the light source component (10);

an incoupling grating (30), the incoupling grating (30) being disposed on the optical waveguide sheet (20), the incoupling grating (30) being for optically coupling the image into the optical waveguide sheet (20);

the light-coupling-out grating (40) is arranged on the optical waveguide sheet (20) and is positioned on the same side surface of the optical waveguide sheet (20) as the light-coupling-in grating (30), the light-coupling-out grating (40) is used for receiving image light of the light-coupling-in grating (30), and the light-coupling-out grating (40) is used for coupling the image light out of the optical waveguide sheet (20);

the two-dimensional angle adjusting structure (50), two-dimensional angle adjusting structure (50) are one or more, and at least one of the coupling-in path of coupling-in grating (30) and the light-out path of coupling-out grating (40) is provided with two-dimensional angle adjusting structure (50).

2. The optical waveguide system of claim 1,

when the two-dimensional angle adjusting structure (50) is one, the two-dimensional angle adjusting structure (50) is arranged on the coupling-in path of the coupling-in grating (30) or on the light-out path of the coupling-out grating (40);

when the two-dimensional angle adjusting structures (50) are multiple, the two-dimensional angle adjusting structures (50) are respectively arranged on the coupling-in path of the coupling-in grating (30) and the light-emitting path of the coupling-out grating (40).

3. Optical waveguide system according to claim 2, characterized in that the two-dimensional angle adjusting structure (50) is a two-dimensional angle magnifier, which is placed in the coupling path of the coupling grating (30) in the opposite direction to the two-dimensional angle magnifier in the coupling path of the coupling grating (40).

4. The optical waveguide system according to claim 1, wherein the two-dimensional angle adjusting structure (50) includes a volume bragg grating layer (51), the volume bragg grating layer (51) is a plurality of layers, the plurality of layers (51) are stacked, and grating vector surfaces of at least two layers (51) of the plurality of layers (51) are disposed at an angle.

5. The optical waveguide system of claim 4, wherein grating vector planes of at least some adjacent two of the plurality of layers of the volume Bragg grating layers (51) are perpendicular to each other.

6. Optical waveguide system according to claim 4, characterized in that the material of the volume Bragg grating layer (51) is one of PTR glass, liquid crystal and a photosensitive resin material.

7. The optical waveguide system of claim 1, wherein the two-dimensional angular adjustment structure (50) is one of a liquid crystal optical phased array, a liquid crystal polarization grating, and a cascaded optical phased array.

8. Optical waveguide system according to claim 1, characterized in that the light source assembly (10) comprises:

a micro display (11), the micro display (11) for emitting image light;

a collimator lens (12), the collimator lens (12) for collimating image light emitted by the micro display (11);

wherein, the micro display (11) is one of OLED, MicroLED, LBS, LCOS and LED.

9. The optical waveguide system according to any one of claims 1 to 8, further comprising a turning grating disposed on the optical waveguide sheet (20) and located on the same side surface of the optical waveguide sheet (20) as the incoupling grating (30), the turning grating being configured to receive image light of the incoupling grating (30), and the outcoupling grating (40) being configured to receive image light of the turning grating.

10. A display device comprising the light guide system of any one of claims 1 to 9.

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