Display device and head-up display system

Abstract

The utility model discloses a display device and a head-up display system, and relates to the technical field of head-up display.The display device comprises a first light machine, a second light machine, a third light machine and an optical waveguide, the first light machine, the second light machine and the third light machine are used for emitting first image light, second image light and third image light respectively, the optical waveguide is used for coupling in the first image light, the second image light and the third image light, and enabling the first image light to be coupled out of the first coupling-out area, the second image light to be coupled out of the second coupling-out area and the third image light to be coupled out of the third coupling-out area; a second coupling-out area and a third coupling-out area are arranged on two sides of a first coupling-out area along a first direction of an optical waveguide target surface, and the first coupling-out area, the second coupling-out area and the third coupling-out area are not arranged at the same height along a second direction of the target surface. The large field angle of the display device is achieved, meanwhile, high energy transmission efficiency is achieved, and the uniformity and the chromaticity of a displayed image are improved.

Description

Technical Field

[0001] The present application relates to the field of head-up display technology, and more specifically, to a display device and a head-up display system. Background Art

[0002] A head-up display (HUD) system is a driver-centric system that projects important driving information, such as speed and navigation, onto the windshield in front of the driver. Incorporating augmented reality (AR) technology, the AR-HUD system allows the driver to simultaneously observe the real environment and receive prompts, eliminating blind spots. Therefore, to enhance the driver's driving experience, further improving the display quality of the AR-HUD system is crucial. Utility Model Content

[0003] Based on the above background, the present application proposes a display device and a head-up display system.

[0004] In a first aspect, an embodiment of the present application provides a display device, comprising a first optical engine, a second optical engine, and a third optical engine, wherein the first optical engine is configured to emit a first image light, the second optical engine is configured to emit a second image light, and the third optical engine is configured to emit a third image light; and an optical waveguide, wherein the optical waveguide is configured to couple in the first image light, the second image light, and the third image light, and couple the first image light out from a first outcoupling region of the optical waveguide, couple the second image light out from a second outcoupling region of the optical waveguide, and couple the third image light out from a third outcoupling region of the optical waveguide; wherein the first outcoupling region, the second outcoupling region, and the third outcoupling region are arranged on a target surface of the optical waveguide, the second outcoupling region and the third outcoupling region are arranged on both sides of the first outcoupling region along a first direction of the target surface, the first outcoupling region, the second outcoupling region, and the third outcoupling region are not all arranged at the same height along a second direction of the target surface, and the first direction and the second direction intersect.

[0005] Optionally, a distance d between the second outcoupling region and the third outcoupling region along the length direction of the target surface and a length L of the first outcoupling region along the length direction of the target surface satisfy: d≤L.

[0006] Optionally, the second image light emitted by the second optical engine has a smaller field angle than the first image light emitted by the first optical engine, and the third image light emitted by the third optical engine has a smaller field angle than the first image light emitted by the first optical engine.

[0007] Optionally, the image resolution of the second image light emitted by the second optical engine is smaller than the image resolution of the first image light emitted by the first optical engine, and the image resolution of the third image light emitted by the third optical engine is smaller than the image resolution of the first image light emitted by the first optical engine.

[0008] Optionally, the first outcoupling region, the second outcoupling region and the third outcoupling region are all two-dimensional gratings; there is a certain distance between the first outcoupling region and the second outcoupling region along the second direction, and there is also a certain distance between the first outcoupling region and the third outcoupling region along the second direction.

[0009] Optionally, the optical waveguide includes a first waveguide layer, a second waveguide layer, and a third waveguide layer, wherein the first waveguide layer, the second waveguide layer, and the third waveguide layer are arranged in the same plane, the first waveguide layer includes a first incoupling region and a first outcoupling region, the second waveguide layer includes a second incoupling region and a second outcoupling region, and the third waveguide layer includes a third incoupling region and a third outcoupling region; wherein the first image light is coupled into the first waveguide layer through the first incoupling region and is then coupled out from the first outcoupling region after propagating, the second image light is coupled into the second waveguide layer through the second incoupling region and is then coupled out from the second outcoupling region after propagating, and the third image light is coupled into the third waveguide layer through the third incoupling region and is then coupled out from the third outcoupling region after propagating.

[0010] Optionally, the first coupling region, the second coupling region and the third coupling region are all one-dimensional gratings.

[0011] Optionally, the optical waveguide further includes a fourth coupling-in region; wherein the first image light is coupled into the optical waveguide through a first region on the fourth coupling-in region and then coupled out from the first coupling-out region; the second image light is coupled into the optical waveguide through a second region on the fourth coupling-in region and then coupled out from the second coupling-out region; and the third image light is coupled into the optical waveguide through a third region on the fourth coupling-in region and then coupled out from the third coupling-out region; wherein the first region does not overlap with the second region and the third region.

[0012] Optionally, the first outcoupling region, the second outcoupling region and the third outcoupling region are all two-dimensional gratings, the fourth incoupling region is also a two-dimensional grating, and the grating vector of the fourth incoupling region, the grating vector of the first outcoupling region, the grating vector of the second outcoupling region, and the grating vector of the third outcoupling region are all the same.

[0013] In a second aspect, an embodiment of the present application further provides a head-up display system, which includes display glass and the display device as described above, wherein the first image light, the second image light, and the third image light emitted by the display device arrive at different positions on the display glass and are reflected to an observation position.

[0014] Therefore, the present application provides a display device and head-up display system, wherein the display device includes: a first optical engine, a second optical engine, a third optical engine, and an optical waveguide, wherein the first optical engine is configured to emit a first image light, the second optical engine is configured to emit a second image light, and the third optical engine is configured to emit a third image light; the optical waveguide is configured to couple the first image light, the second image light, and the third image light, and couple the first image light out of a first outcoupling region of the optical waveguide, the second image light out of a second outcoupling region of the optical waveguide, and the third image light out of a third outcoupling region of the optical waveguide. The display device provided by the present application achieves a large FOV of the display device while having high energy transfer efficiency, thereby improving the uniformity and color of the displayed image. By arranging the second and third outcoupling regions on either side of the first outcoupling region along a first direction of a target surface of the optical waveguide, and by not all arranging the first, second, and third outcoupling regions at the same height along a second direction of the target surface, the display device achieves a large FOV while having high energy transfer efficiency, thereby improving the uniformity and color of the displayed image.

[0015] Other features and advantages of the embodiments of the present application will be described in the following description and, in part, will become apparent from the description or be understood by practicing the embodiments of the present application. The objectives and other advantages of the embodiments of the present application can be achieved and obtained through the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram showing the principle of light propagation in an optical waveguide.

[0018] Figure 2 A structural front view of a display device proposed in an embodiment of the present application is shown.

[0019] Figure 3 A top view of the structure of a display device proposed in an embodiment of the present application is shown.

[0020] Figure 4 A schematic diagram of image display of a display device proposed in an embodiment of the present application is shown.

[0021] Figure 5 A top view of the structure of another display device proposed in an embodiment of the present application is shown.

[0022] Figure 6 A top view of the structure of another display device proposed in an embodiment of the present application is shown.

[0023] Figure 7 A head-up display system according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work fall within the scope of protection of the present application.

[0025] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0026] In the current head-up display system, AR-HUD system can be divided into free-form surface AR-HUD and optical waveguide AR-HUD according to the different light propagation devices. Generally speaking, optical waveguide AR-HUD consists of an optical engine and an optical waveguide. The optical engine is used to emit image light, and the optical waveguide is used to propagate image light. For details, please refer to Figure 1 , Figure 1A schematic diagram illustrating the principle of light propagation in an optical waveguide is shown. Light is coupled into the optical waveguide 100 through a coupling device 101 disposed on the optical waveguide 100, undergoes total internal reflection, and then reaches a coupling device 102 disposed on the optical waveguide 100. The coupling device 101 and the coupling device 102 can use diffraction gratings to achieve light coupling and decoupling. Therefore, optical waveguide AR-HUDs can utilize the pupil expansion characteristics of diffraction gratings to replicate light and significantly reduce the size of the HUD system, leading to their widespread application in HUD systems with large field of view (FOV).

[0027] However, existing waveguide AR-HUD technology with a wide field of view (FOV) still suffers from low efficiency and poor color rendering. The inventors discovered that a larger FOV corresponds to a larger display screen, which means the area of ​​the diffraction grating used to couple light in the waveguide AR-HUD increases. However, due to the diffraction characteristics of the diffraction grating, this increased grating area makes it more difficult to achieve uniform brightness and color distribution, and also reduces the pixel resolution of the displayed image.

[0028] Therefore, see Figure 2 , Figure 2 A front view of the structure of a display device proposed in an embodiment of the present application is shown. Specifically, the display device 200 includes: a first optical engine 201, a second optical engine 202, a third optical engine 203 and an optical waveguide 210. The first optical engine 201 is used to emit a first image light L1, the second optical engine 202 is used to emit a second image light L2, and the third optical engine 203 is used to emit a third image light L3. The optical waveguide 210 is used to couple in and propagate the first image light L1, the second image light L2 and the third image light L3, and couple the first image light L1, the second image light L2 and the third image light L3 out at corresponding positions.

[0029] As an embodiment, the optical waveguide 210 may have an incoupling region (eg Figure 1), a first outcoupling region 211, a second outcoupling region 212 and a third outcoupling region 213, and the first image light L1, the second image light L2 and the third image light L3 can all be coupled into the optical waveguide 210 from the coupling-in region. Furthermore, the first outcoupling region 211, the second outcoupling region 212 and the third outcoupling region 213 are all arranged on the target surface S1 of the optical waveguide 210. The coupling-in region is further used to, after coupling the first image light L1 into the optical waveguide 210, cause the first image light L1 to propagate toward the first outcoupling region 211, so that the first image light L1 is incident on the first outcoupling region 211 and then decoupled from the first outcoupling region 211; similarly, the coupling-in region is further used to, after coupling the second image light L2 into the optical waveguide 210, cause the second image light L2 to propagate toward the second outcoupling region 212, so that the second image light L2 is incident on the second outcoupling region 212 and then decoupled from the second outcoupling region 212; the coupling-in region is further used to, after coupling the third image light L3 into the optical waveguide 210, cause the third image light L3 to propagate toward the third outcoupling region 213, so that the third image light L3 is incident on the third outcoupling region 213 and then decoupled from the third outcoupling region 213.

[0030] See also Figure 3 , Figure 3 The top view of the structure of a display device proposed in an embodiment of the present application is shown. Specifically, the second outcoupling region 212 and the third outcoupling region 213 are arranged on both sides of the first outcoupling region 211 along the first direction x of the target surface S1. The first outcoupling region 211, the second outcoupling region 212 and the third outcoupling region 213 are arranged along the second direction y of the target surface S1 and are not all arranged at the same height, wherein the first direction x and the second direction y intersect, and further, the first direction x and the second direction y are orthogonal. As an embodiment, the second outcoupling region 212 and the third outcoupling region 213 may not be at the same height along the y direction, such as Figure 3 As shown, the second outcoupling region 212 and the first outcoupling region 211 are not at the same height along the y direction, and the third outcoupling region 213 and the first outcoupling region 211 are also not at the same height along the y direction.

[0031] As an embodiment, a distance d exists between the second outcoupling region 212 and the third outcoupling region 213 along the first direction x of the target surface S1, and this distance d and the length L of the first outcoupling region 211 along the first direction x of the target surface S1 satisfy the following relationship: d ≤ L. Furthermore, the imaging distribution characteristics of the light outcoupling from the first outcoupling region 211, the second outcoupling region 212, and the third outcoupling region 213 correspond to the distribution characteristics of the first outcoupling region 211, the second outcoupling region 212, and the third outcoupling region 213. Therefore, when the overall FOV of the display device remains unchanged, setting the distance d between the second outcoupling region 212 and the third outcoupling region 213 to be less than the length L of the first outcoupling region 211 can increase the imaging area of ​​the display device, allowing the display device to display more content under the same FOV. Furthermore, when the display device is used in a vehicle head-up display system, the proportional relationship between L and d can be set differently based on the road type (such as urban roads or highways). For example, the road conditions on urban roads are relatively complicated, and it is not appropriate to display too much information within the driver's field of view. In this case, the size of d can be increased to reduce the imaging area of ​​the head-up display system while the areas of the first outcoupling area 211, the second outcoupling area 212, and the third outcoupling area 213 remain unchanged (that is, L remains unchanged). On the other hand, the road on the highway is open and the road conditions are simple. In this case, the size of d can be reduced to increase the imaging area of ​​the head-up display system while L remains unchanged, thereby displaying more information for the driver's attention.

[0032] Furthermore, since the second outcoupling region 212 and the third outcoupling region 213 are arranged on both sides of the first outcoupling region 211 along the first direction x, the final imaging effect is that the imaging range of the second image light L2 emitted by the second outcoupling region 212 and the imaging range of the third image light L3 emitted by the third outcoupling region 213 are located on both sides of the imaging range of the first image light L1 emitted by the first outcoupling region 211. In one embodiment, the second image light L2 emitted by the second optical engine 202 has a smaller field of view than the first image light L1 emitted by the first optical engine 201, and the third image light L3 emitted by the third optical engine 203 has a smaller field of view than the first image light L1 emitted by the first optical engine 201. The image resolution of the second image light L2 emitted by the second optical engine 202 is smaller than the image resolution of the first image light L1 emitted by the first optical engine 201, and the image resolution of the third image light L3 emitted by the third optical engine 203 is smaller than the image resolution of the first image light L1 emitted by the first optical engine 201. Furthermore, the image resolution of the image light emitted by the optical engine can be adjusted by adjusting the resolution of the digital micromirror device (DMD) in the optical engine. Therefore, because the human eye has a weaker perception of image resolution in the peripheral field of view, the image resolution and field of view of the second and third optical engines used for imaging on both sides can be reduced to reduce system costs.

[0033] As an embodiment, the first outcoupling region 211, the second outcoupling region 212 and the third outcoupling region 213 are all two-dimensional gratings, which can be holographic gratings, volume gratings or relief gratings, etc. The two-dimensional gratings have multiple diffraction directions and can propagate the light incident thereon in multiple directions, thereby achieving a pupil expansion effect. Furthermore, the first outcoupling region 211, the second outcoupling region 212 and the third outcoupling region 213 are not adjacent to each other. For details, please refer to Figure 3 There is a certain distance between the first outcoupling region 211 and the second outcoupling region 212 along the y direction, there is also a certain distance between the first outcoupling region 211 and the third outcoupling region 213 along the y direction, and there is a distance d between the second outcoupling region 212 and the third outcoupling region 213 along the x direction. Therefore, after the first image light L1, the second image light L2 and the third image light L3 are coupled out of the optical waveguide 210 through the first outcoupling region 211, the second outcoupling region 212 and the third outcoupling region 213 respectively, the images finally displayed on the display surface are also separated from each other, and the image display effect of the final imaging of the first image light L1, the second image light L2 and the third image light L3 can be referred to as follows: Figure 3The arrangement of the outcoupling areas corresponding to the image light, that is, the second image light L2 imaging and the third image light L3 imaging are arranged on both sides of the first image light L1 imaging along the horizontal direction of the display surface, the first image light L1 imaging, the second image light L2 imaging and the third image light L3 imaging are not located at the same height along the vertical direction of the display surface, and the first image light L1 imaging, the second image light L2 imaging and the third image light L3 imaging are not adjacent to each other.

[0034] According to the above analysis, by setting up three optical engines as image sources to emit image light, and having the image light emitted by different optical engines propagate through the optical waveguide and then be coupled out from different coupling areas, the display screen is enlarged, that is, a large FOV of the display device is achieved. At the same time, it is ensured that the image light emitted from the first coupling area, the second coupling area, and the third coupling area all have high energy transfer efficiency, thereby improving the uniformity and color of the final displayed image. For further information, please refer to Figure 4 , Figure 4 FIG1 shows a schematic diagram of an image display device proposed in an embodiment of the present application, in particular, Figure 4 The figure shows an image display diagram when the display device is applied to a head-up display system of a vehicle, wherein: Figure 4 The lower middle display image is composed of Figure 2 and Figure 3 The first image light L1 coupled out of the first outcoupling region 211 is formed. Figure 4 The upper left display image is composed of Figure 2 and Figure 3 The second image light L2 coupled out of the second outcoupling region 212 is formed. Figure 4 The upper right display image is composed of Figure 2 and Figure 3 The third image light L3 coupled out of the third outcoupling area 213 is formed. It can be seen that the display device proposed in this embodiment, when applied to the head-up display system, takes into account the actual situation of road driving and sets the corresponding outcoupling area distribution characteristics, so that the projected image is displayed not only in the common lane ( Figure 4 In addition to the display image area in the lower middle part), it can also be displayed on the areas on both sides of the road suitable for displaying prompt information ( Figure 4 The display image area in the upper left and upper right parts) not only increases the FOV of the head-up display system, but also can adjust the corresponding image resolution and FOV size based on different areas, thereby minimizing the system cost of the large FOV system.

[0035] As an implementation, see Figure 5 , Figure 5 FIG. 1 shows a top view of another display device proposed in an embodiment of the present application. Specifically, the display device includes: a first optical engine, a second optical engine, a third optical engine ( Figure 5The optical waveguide 500 includes a first optical engine for emitting a first image light L1, a second optical engine for emitting a second image light L2, and a third optical engine for emitting a third image light L3. The optical waveguide 500 includes a first waveguide layer 510, a second waveguide layer 520, and a third waveguide layer 530, and the first waveguide layer 510, the second waveguide layer 520, and the third waveguide layer 530 are arranged in the same plane. Furthermore, the first waveguide layer 510 includes a first incoupling region 511 and a first outcoupling region 512, the second waveguide layer 520 includes a second incoupling region 521 and a second outcoupling region 522, and the third waveguide layer 530 includes a third incoupling region 531 and a third outcoupling region 532. Thus, the first image light L1 emitted by the first optical engine can be coupled into the first waveguide layer 510 through the first incoupling region 511, and then coupled out from the first outcoupling region 512 after propagating in the first waveguide layer 510. The second image light L2 emitted by the second optical engine can be coupled into the second waveguide layer 520 through the second incoupling region 521, and then coupled out from the second outcoupling region 522 after propagating in the second waveguide layer 520. The third image light L3 emitted by the third optical engine can be coupled into the third waveguide layer 530 through the third incoupling region 531, and then coupled out from the third outcoupling region 532 after propagating in the third waveguide layer 530. As an embodiment, the first coupling region 511, the second coupling region 521 and the third coupling region 531 are all one-dimensional gratings, illustratively, they can be straight gratings, slanted gratings, or blazed gratings, which are used to propagate the incident image light along a specific direction to the corresponding coupling region.

[0036] In this embodiment, by separating the incoupling and outcoupling regions of each image light, each waveguide only needs to transmit image light within its respective FOV. This greatly reduces the difficulty of optimizing the grating parameters of the incoupling and outcoupling regions within each waveguide, achieving zoned image display with high energy transfer efficiency. Furthermore, by coupling the three image lights into and out of three different waveguides, the problem of stray light that may be generated during the propagation of image light due to different outcoupling regions on the same waveguide and the grating vectors of the different outcoupling regions is avoided. It is understood that some of the implementation methods and related effects of this embodiment can be referred to the above description and will not be repeated here.

[0037] As an implementation, see Figure 6 , Figure 6 FIG. 1 shows a top view of the structure of another display device proposed in an embodiment of the present application. Specifically, the display device includes: a first optical engine, a second optical engine, and a third optical engine ( Figure 6(not shown) and an optical waveguide 600, wherein the first optical engine is used to emit the first image light L1, the second optical engine is used to emit the second image light L2, and the third optical engine is used to emit the third image light L3. Furthermore, the optical waveguide 600 includes a first outcoupling region 611, a second outcoupling region 612, and a third outcoupling region 613, and also includes a fourth incoupling region 620. Furthermore, the fourth incoupling region 620 has a first region 621, a second region 622, and a third region 623, and the first region 621, the second region 622, and the third region 623 do not overlap with each other. Exemplarily, the first region 621, the second region 622, and the third region 623 may not overlap with each other by having the first region 621, the second region 622, and the third region 623 occupy different ranges of central angles in the fourth incoupling region 620. Specifically, the first image light L1 emitted by the first optical machine can be coupled into the optical waveguide 600 through the first area 621 on the fourth coupling-in area 620, and coupled out from the first coupling-out area 611 after propagating in the optical waveguide 600. The second image light L2 emitted by the second optical machine can be coupled into the optical waveguide 600 through the second area 622 on the fourth coupling-in area 620, and coupled out from the second coupling-out area 621 after propagating in the optical waveguide 600. The third image light L3 emitted by the third optical machine can be coupled into the optical waveguide 600 through the third area 623 on the fourth coupling-in area 620, and coupled out from the third coupling-out area 631 after propagating in the optical waveguide 600. As an embodiment, the fourth coupling-in region 620 is a two-dimensional grating. Since the two-dimensional grating has the characteristic of multi-directional diffraction, the fourth coupling-in region 620 can propagate the first image light L1, the second image light L2 and the third image light L3 incident on different regions to the corresponding decoupling regions in different directions. Furthermore, the first decoupling region 611, the second decoupling region 612 and the third decoupling region 613 are also two-dimensional gratings. The grating vector of the fourth coupling-in region 620, the grating vector of the first decoupling region 611, the grating vector of the second decoupling region 612 and the grating vector of the third decoupling region 613 are all the same. By making the grating vectors of all the coupling-in gratings and decoupling gratings the same, the wave vector of the image light remains consistent with that before being coupled into the waveguide, regardless of whether it is coupled out by the first decoupling grating, the second decoupling grating or the third decoupling grating, thereby avoiding the problem of stray light caused by different grating vectors.

[0038] In this embodiment, separate outcoupling regions are provided on the optical waveguide, and image light of different FOVs is coupled into the same incoupling region through different, non-overlapping regions. The light coupled into each region is then coupled out from a corresponding outcoupling region, so that each outcoupling region only couples out image light of a portion of its FOV. This significantly reduces the difficulty of optimizing the grating parameters of the outcoupling regions on the optical waveguide, achieving partitioned image display with high energy transfer efficiency. It is understood that some of the implementation methods and related effects of this embodiment can be referred to the above description and will not be repeated here.

[0039] Therefore, this embodiment provides a display device, including: a first optical engine, a second optical engine, a third optical engine and an optical waveguide, wherein the first optical engine is used to emit a first image light, the second optical engine is used to emit a second image light, and the third optical engine is used to emit a third image light; the optical waveguide is used to couple in the first image light, the second image light and the third image light, and couple the first image light out from the first outcoupling region of the optical waveguide, couple the second image light out from the second outcoupling region of the optical waveguide, and couple the third image light out from the third outcoupling region of the optical waveguide. The display device provided in this embodiment arranges the second outcoupling region and the third outcoupling region on both sides of the first outcoupling region along the length direction of the target surface of the optical waveguide. The first outcoupling region, the second outcoupling region, and the third outcoupling region are not all arranged at the same height along the width direction of the target surface, and the first outcoupling region is not immediately adjacent to the second outcoupling region and the third outcoupling region. This achieves a large FOV for the display device while having high energy transfer efficiency, improving the uniformity and color of the displayed image, and furthermore, adjusting the corresponding image resolution and FOV size based on different regions, thereby minimizing the system cost of the large FOV system.

[0040] See also Figure 7 , Figure 7 A head-up display system according to an embodiment of the present application is shown, comprising display glass 710 and a display device 720 as described in the above embodiment. First image light L1, second image light L2, and third image light L3 emitted by the display device 720 reach different positions on the display glass 720 and are reflected to an observation position, where the observation position can be a human eye. For further details and beneficial effects, please refer to the above embodiment and will not be repeated here.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A display device, characterized in that: include: a first optical engine, a second optical engine, and a third optical engine, wherein the first optical engine is configured to emit a first image light, the second optical engine is configured to emit a second image light, and the third optical engine is configured to emit a third image light; an optical waveguide for coupling in the first image light, the second image light, and the third image light, and coupling the first image light out from a first outcoupling region of the optical waveguide, coupling the second image light out from a second outcoupling region of the optical waveguide, and coupling the third image light out from a third outcoupling region of the optical waveguide; The first outcoupling region, the second outcoupling region and the third outcoupling region are arranged on the target surface of the optical waveguide, the second outcoupling region and the third outcoupling region are arranged on both sides of the first outcoupling region along the first direction of the target surface, the first outcoupling region, the second outcoupling region and the third outcoupling region are not all arranged at the same height along the second direction of the target surface, and the first direction and the second direction intersect.

2. The display device according to claim 1, wherein A distance d between the second outcoupling region and the third outcoupling region along the length direction of the target surface and a length L of the first outcoupling region along the length direction of the target surface satisfy: d≤L.

3. The display device according to claim 1, wherein The second image light emitted by the second optical engine has a smaller field angle than the first image light emitted by the first optical engine, and the third image light emitted by the third optical engine has a smaller field angle than the first image light emitted by the first optical engine.

4. The display device according to claim 1, wherein The image resolution of the second image light emitted by the second optical engine is smaller than the image resolution of the first image light emitted by the first optical engine, and the image resolution of the third image light emitted by the third optical engine is smaller than the image resolution of the first image light emitted by the first optical engine.

5. The display device according to claim 1, wherein The first outcoupling region, the second outcoupling region and the third outcoupling region are all two-dimensional gratings; There is a certain distance between the first outcoupling region and the second outcoupling region along the second direction, and there is also a certain distance between the first outcoupling region and the third outcoupling region along the second direction.

6. The display device according to claim 1, wherein The optical waveguide includes a first waveguide layer, a second waveguide layer, and a third waveguide layer, wherein the first waveguide layer, the second waveguide layer, and the third waveguide layer are arranged in the same plane, the first waveguide layer includes a first incoupling region and a first outcoupling region, the second waveguide layer includes a second incoupling region and a second outcoupling region, and the third waveguide layer includes a third incoupling region and the third outcoupling region; The first image light is coupled into the first waveguide layer through the first coupling-in region and is coupled out from the first coupling-out region after propagation; the second image light is coupled into the second waveguide layer through the second coupling-in region and is coupled out from the second coupling-out region after propagation; and the third image light is coupled into the third waveguide layer through the third coupling-in region and is coupled out from the third coupling-out region after propagation.

7. The display device according to claim 6, wherein: The first coupling region, the second coupling region and the third coupling region are all one-dimensional gratings.

8. The display device according to claim 1, wherein The optical waveguide further includes a fourth coupling region; The first image light is coupled into the optical waveguide through the first region on the fourth coupling-in region and then coupled out from the first coupling-out region; the second image light is coupled into the optical waveguide through the second region on the fourth coupling-in region and then coupled out from the second coupling-out region; and the third image light is coupled into the optical waveguide through the third region on the fourth coupling-in region and then coupled out from the third coupling-out region. The first area does not overlap with the second area and the third area.

9. The display device according to claim 8, wherein The first outcoupling region, the second outcoupling region and the third outcoupling region are all two-dimensional gratings, the fourth incoupling region is also a two-dimensional grating, and the grating vector of the fourth incoupling region, the grating vector of the first outcoupling region, the grating vector of the second outcoupling region, and the grating vector of the third outcoupling region are all the same.

10. A head-up display system, characterized in that: The display device comprises display glass and any one of claims 1 to 9, wherein the first image light, the second image light and the third image light emitted by the display device arrive at different positions on the display glass and are reflected to an observation position.

Images