Display system

Abstract

Embodiments of the present application provide a display system, comprising an optical engine, an optical waveguide and a pre-pupil expanding waveguide, the optical engine is configured to output image light, the optical waveguide comprises a coupling-in region and a coupling-out region, and the first light in the image light is incident on the pre-pupil expanding waveguide through the coupling-in region of the optical waveguide; the pre-pupil expanding waveguide is configured to couple out at least part of the first light in the direction of the coupling-in region after pupil expansion, and the pre-pupil expanding waveguide is further configured to rotate relative to the optical waveguide, so that the expanded first light is incident on different positions of the coupling-in region at different times, at least part of the expanded first light is coupled into the optical waveguide by the coupling-in region, and the coupling-out region is configured to couple out at least part of the image light transmitted in the optical waveguide. The entire display system does not need to increase the size of the optical engine, nor does it need to thin the optical waveguide. The volume of the entire display system is controllable, the manufacturing cost is lower, the pupil is continuous, and the technical problem of discontinuous pupil expansion of a small pupil optical engine is solved.

Description

Technical Field

[0001] This application relates to the field of display technology, and more specifically to a display system. Background Technology

[0002] As virtual reality technology matures, micro-projection is gradually entering the commercialization stage. These hardware display systems typically consist of two parts: a micro-optical engine and an optical combiner. The micro-optical engine is the device used to generate image light. The optical combiner combines the ambient light and the image light, allowing the human eye to simultaneously observe both the environmental light and the image information generated by the optical engine.

[0003] The optical assemblies largely determine the overall form of AR display devices. Currently, mature solutions on the market include prisms, freeform surfaces, BirdBath, and waveguides. The first three solutions cannot make AR glasses lightweight products in terms of size, field of view, and transparency, and also affect the wearing experience. Waveguides, on the other hand, can solve the inherent contradiction between field of view and size. In terms of optical effects, appearance, and mass production prospects, waveguides have very good development potential.

[0004] However, current optical waveguides have the following problems: in order to compress the size of the optical engine, the exit pupil size is reduced, which results in a large gap between adjacent replicated light spots. This leads to a relatively sparse distribution of light spots received on the surface of the human eye pupil with a small entrance pupil diameter. Utility Model Content

[0005] This application provides a display system to at least partially improve the above-mentioned technical problems.

[0006] This application provides a display system including an optical engine, an optical waveguide, and a pre-pupil waveguide. Both the optical waveguide and the pre-pupil waveguide are located on the output optical path of the optical engine. The optical waveguide is positioned between the optical engine and the pre-pupil waveguide. The optical engine outputs image light. The optical waveguide includes an insertion region and an exit region. A first ray of the image light passes through the insertion region of the optical waveguide and is incident on the pre-pupil waveguide. The pre-pupil waveguide is used to dilate at least a portion of the first ray and then couple it out towards the insertion region. The pre-pupil waveguide is also configured to rotate relative to the optical waveguide so that the dilated first ray is incident at different positions in the insertion region at different times. At least a portion of the dilated first ray is coupled into the optical waveguide and transmitted through the insertion region. The exit region is used to couple out at least a portion of the image light transmitted in the optical waveguide.

[0007] In one embodiment, the coupling region is also used to couple a second ray of image light into the optical waveguide for transmission, wherein the second ray forms a plurality of first replicated light spots when transmitted in the optical waveguide, and adjacent first replicated light spots are separated from each other.

[0008] In one embodiment, the first light ray after pupil dilation transmitted in the optical waveguide coupled into the coupling region forms a plurality of second replicated light spots, with at least partial overlap between adjacent second replicated light spots.

[0009] In one embodiment, the pre-pupil waveguide includes a driving device, a support member, and a waveguide element. The waveguide element is connected to the support member. The driving device is used to drive the support member to rotate, thereby driving the waveguide element to rotate. A one-dimensional grating is provided on the waveguide element.

[0010] In one embodiment, the waveguide element is configured to rotate about the optical axis of the optomechanism.

[0011] In one embodiment, the support member has a first surface and a second surface disposed opposite to each other, the driving device is connected to the second surface of the support member, the waveguide is connected to the edge of the first surface of the support member, a gap is formed between the waveguide member and the support member, and the gap is filled with air.

[0012] In one embodiment, the support member is glass, and a reflective film is provided on the first or second surface of the support member; or, the support member is a metal member, and the first surface of the metal member has a reflective function.

[0013] In one embodiment, the waveguide element includes a first waveguide and a second waveguide, the second waveguide being disposed on the side of the first waveguide away from the optical waveguide, the second waveguide being connected to the support member, a one-dimensional grating being disposed on the first waveguide, a one-dimensional grating being disposed on the second waveguide, and the grating period and grating direction of the one-dimensional grating on the first waveguide and the one-dimensional grating on the second waveguide being the same.

[0014] In one embodiment, an adhesive is provided on the surface of the second waveguide facing the first waveguide, the first waveguide is adhered to the adhesive, the adhesive is offset from the one-dimensional grating disposed on the second waveguide, and a gap is formed between the first waveguide and the second waveguide, the gap being filled with air.

[0015] In one embodiment, the first waveguide and the second waveguide are arranged orthogonally. In one embodiment, the area of ​​the one-dimensional grating on the waveguide element is smaller than the area of ​​the coupling region, and the waveguide element is rotated at least 360 degrees so that the first light rays emitted from the pre-pupil waveguide to the coupling region at different times after pupil expansion can fill the coupling region.

[0016] The display system provided in this application embodiment, by setting a pre-pupil waveguide, can rotate during operation. When the pre-pupil waveguide is stationary, the first ray of the image light emitted from the optical engine first passes through the coupling region of the optical waveguide and reaches the pre-pupil waveguide. The pre-pupil waveguide performs one-dimensional pupil expansion on the first ray of the incident image light. The expanded first ray is coupled out towards the coupling region of the optical waveguide and recoupled into the coupling region of the optical waveguide. Since the pre-pupil waveguide is also configured to rotate relative to the optical waveguide, the first ray recoupled into the optical waveguide is incident at different positions in the coupling region, achieving a two-dimensional pupil expansion effect through the time accumulation effect. At the same time, it makes the exit pupil continuous, solving the technical problem of discontinuous pupil expansion of small exit pupil optical engines. The entire display system does not require increasing the size of the optical engine, nor does it require thinning of the optical waveguide. The volume of the entire display system is controllable, and the manufacturing cost is lower. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a display system shown in Embodiment 1 of this application.

[0019] Figure 2 This is a schematic diagram of the structure of a pre-pupil waveguide in a display system, as shown in Embodiment 1 of this application.

[0020] Figure 3 This is a schematic diagram of the structure of the first waveguide in a display system as shown in Embodiment 1 of this application.

[0021] Figure 4 This is a schematic diagram of the pre-pupil waveguide structure in a display system, as shown in Embodiment 2 of this application.

[0022] Figure 5 This is a schematic diagram of the structure of a second waveguide in a display system as shown in Embodiment 2 of this application. Detailed Implementation

[0023] 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 with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0024] In this application, unless otherwise expressly specified or limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components; they can refer to mere surface contact; or they can refer to surface contact connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] Furthermore, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as referring to specific or particular structures. The terms "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this application, as well as the features of different embodiments or examples.

[0026] Current optical waveguides suffer from the following problems: in order to reduce the size of the optical engine, the exit pupil size is reduced, resulting in a large gap between adjacent replicated light spots. This leads to a relatively sparse distribution of light spots received on the pupil surface under a small entrance pupil diameter. The low saturation of the light spots on the pupil surface manifests in the image perceived by the human eye as uneven brightness distribution, such as producing striped defects and the "screen door" effect.

[0027] In some cases, a small exit pupil size may be unavoidable for optical engines. For example, when using lasers as the light source to illuminate panels such as DMDs and LCoS, the exit pupil size may be less than 1 mm if angle diffusers are not desired in the optical system to reduce system size. Alternatively, when using laser beam scanning (LBS), the need to limit the size of MEMS mirrors in the LBS system to ensure sufficient frame rate and scanning FOV also results in a small exit pupil size. Furthermore, in the consumer AR glasses field, continuously shrinking the size of optical engines to improve user comfort is an inevitable trend, which also accompanies the reduction of the optical engine's exit pupil size. Theoretically, the density of the expanded pupil spot can be increased by reducing the waveguide thickness, thus adapting to a smaller optical engine exit pupil. However, thinner waveguides present manufacturing challenges, and when using highly coherent light sources such as lasers, reducing the waveguide thickness may increase the severity of interference effects in the waveguide.

[0028] Based on this, this application proposes a display system in order to improve the above-mentioned technical problems. The following describes this application in detail with reference to specific embodiments.

[0029] Example 1 See Figure 1 This embodiment provides a display system 10, including an optomechanism 20, an optical waveguide 30, and a pre-pupil waveguide 60. The optomechanism 20 generates output image light. The optical waveguide 30 includes an input region 33 and an output region 34. The input region 33 receives the image light, and the output region 34 outputs the image light to the human eye. The pre-pupil waveguide 60 dilates the pupil of the image light.

[0030] In a more specific embodiment, the optical engine 20 can be a device based on LCoS, DMD, or LCD, etc., and this embodiment is not limited to this. Liquid Crystal on Silicon (LCoS) is a novel microdisplay technology that combines semiconductor and LCD technologies. DLP projection display technology is a projection display technology based on DMD devices. Of course, the optical engine 20 can also use other imaging display technologies to generate image light, such as using a microled panel to generate image light, and this is not specifically limited here.

[0031] In some embodiments, the image light can be a combined light formed by sequentially combining red, green and blue light. In other embodiments, the image light can be monochromatic light. In other embodiments, the image light can be a combined light that simultaneously contains red, green and blue light. This embodiment does not limit this.

[0032] The optical waveguide 30 can be a flat, transparent device located in the output optical path of the optomechanical system 20. The optical waveguide 30 includes an input region 33 and an output region 34. The input region 33 receives image light, and the output region 34 outputs the image light. The optical waveguide 30 can also propagate light. The image light emitted from the optomechanical system 20 is guided to the input region 33, and the output region 34 can be configured to correspond to the user's eye. The optical waveguide 30 has a first surface 31 and a second surface 32 facing away from each other. Both the first surface 31 and the second surface 32 can be planar and can be approximately parallel to each other. The coupling region 33 is used to receive image light, and the coupling region 34 is used to couple the image light out. The coupling region 33 and the coupling region 34 can be set on the same side of the optical waveguide, or they can be set on opposite sides of the optical waveguide. For example, the coupling region 33 is set on the first surface 31, and the coupling region 34 is set on the second surface 32. Specifically, when the image light enters the optical waveguide 30, it propagates in the optical waveguide 30 in the form of total internal reflection. More specifically, when the image light enters the optical waveguide 30, the image light rays can undergo total internal reflection inside the optical waveguide 30 and then travel in the optical waveguide 30.

[0033] In this embodiment, both the coupling-in region 33 and the coupling-out region 34 are disposed on the first surface 31, and the optomechanical unit 20 is located on one side of the first surface 31 of the optical waveguide 30. After image light is coupled into the optical waveguide 30 from the coupling-in region 33, it can propagate towards the coupling-out region 34. More specifically, the coupling region 33 may be provided with a coupling grating 40. After the image light is incident on the coupling grating 40, it is coupled into the optical waveguide 30 by the diffraction effect of the coupling grating 40. The coupling region 34 may be provided with a coupling grating 50, which is used to couple out the image light and project it onto the human eye.

[0034] The pre-pupil waveguide 60 is also located on the output optical path of the optomechanism 20. The pre-pupil waveguide 60 is disposed on the side of the optical waveguide 30 away from the optomechanism 20 and corresponds to the coupling region 33. That is, the optical waveguide 30 is located between the optomechanism 20 and the pre-pupil waveguide 60. In this embodiment, the pre-pupil waveguide 60 is disposed on one side of the second surface 32 of the optical waveguide 30 and corresponds to the coupling region 33. Specifically, the pre-pupil waveguide 60 is corresponding to the coupling grating 40 of the coupling region 33.

[0035] The first ray of the image light emitted from the optical engine 20 passes through the coupling region 33 of the optical waveguide 30 and enters the pre-pupil waveguide 60. The first ray refers to a portion of the image light that passes through the optical waveguide 30 and enters the pre-pupil waveguide 60. The pre-pupil waveguide 60 is used to dilate at least a portion of the first ray and couple it out towards the coupling region 33, then recouple it into the coupling region 33 of the optical waveguide 30. Specifically, after the pre-pupil waveguide 60 dilates at least a portion of the first ray in the image light, the dilated first ray exits towards the optical waveguide 30, re-enters the optical waveguide 30, and is again coupled into the optical waveguide 30 by the coupling grating 40 of the coupling region 33. It then undergoes total internal reflection within the optical waveguide 30 and exits from the coupling region 34.

[0036] The pre-pupil waveguide 60 is configured to rotate relative to the optical waveguide 30. Since the pre-pupil waveguide 60 is also configured to rotate relative to the optical waveguide 30, the first light ray recoupled to the optical waveguide 30 is incident at different positions in the coupling region 33. Through the time accumulation effect, a two-dimensional pupil dilation effect can be achieved, while ensuring continuous exit pupil. This solves the technical problem of discontinuous pupil dilation in small exit pupil optical mechanisms. The rotation axis of the pre-pupil waveguide 60 intersects with the first surface 31 of the optical waveguide 30, so that after the first ray of the image light emitted from the optomechanism 20 passes through the coupling region 33 of the optical waveguide 30 and reaches the pre-pupil waveguide 60, the pre-pupil waveguide 60 can dilate the image light, directing at least a portion of the first ray of the image light toward the optical waveguide 30. In a preferred embodiment, the pre-pupil waveguide 60 is configured to rotate about the optical axis of the optomechanism 20, that is, the pre-pupil waveguide 60 is configured to rotate about a direction perpendicular to the first surface 31 of the optical waveguide 30. In this embodiment, the first ray has a higher probability of being reflected back to the optical waveguide 30 after pupil dilation, which can significantly improve the utilization rate of light.

[0037] For details in this embodiment, please refer to the following: Figure 2 and Figure 3 The pre-pupil waveguide 60 includes a driving device 61, a support member 62, and a waveguide element 65. The driving device 61 can be, for example, a motor. The support member 62 is mounted on the output shaft of the driving device 61. The driving device 61 is used to drive the support member 62 to rotate. The waveguide element 65 is connected to the support member 62. Thus, when the driving device 61 drives the support member 62 to rotate, it drives the waveguide element 65 to rotate. A one-dimensional grating 651 is provided on the surface of the waveguide element 65 facing the optical waveguide 30. When image light enters the waveguide element 65, it is incident on the one-dimensional grating 651. The grating expands the pupil of the image light and then reflects the image light back to the optical waveguide 30.

[0038] The support member 62 can be fixed to the output shaft of the drive device 61 by adhesive bonding. The drive device 61 can be, for example, a motor.

[0039] In this embodiment, the edges of the waveguide element 65 and the support member 62 are connected by adhesive, and a gap 66 is formed between the waveguide element 65 and the support member 62. The gap 66 is filled with air, which avoids disrupting the total internal reflection condition of the image light. After the waveguide element 65 dilates the image light, in order to reflect all the image light back to the waveguide element 30, in this embodiment, the support member 62 is made of glass, and a reflective film is provided on the surface of the support member 62. The reflective film can be provided on the surface of the support member 62 facing the waveguide element 65 and / or the surface of the support member 62 facing away from the waveguide element 65, which can significantly improve the utilization rate of the image light. In another embodiment, the support member 62 can be a metal part, that is, made of metal, and the first surface of the metal part has a reflective function. For example, the support member 62 can be a metal part made of silver. In some other embodiments, the support member 62 can also be other components with reflective functions, which are not limited in this embodiment.

[0040] At least a portion of the first light ray after pupil dilation is transmitted through the coupled-in region 33 into the optical waveguide 30, and the coupled-out region 34 is used to couple out at least a portion of the image light transmitted in the optical waveguide 30, for example, to the human eye.

[0041] In this embodiment, the area of ​​the one-dimensional grating 651 on the waveguide element 65 is smaller than the area of ​​the coupling region 33. This ensures that the first light ray after pupil dilation by the one-dimensional grating 651 can completely enter the optical waveguide 30 from the coupling region 33 when it exits towards the coupling region 33. During the rotation of the pre-pupil waveguide 60 relative to the optical waveguide 30, the waveguide element 65 rotates at least 360 degrees so that the first light ray after pupil dilation emitted from the pre-pupil waveguide 60 to the coupling region 33 at different times can fill the coupling region 33, forming a continuous pupil dilation image light.

[0042] When the image light emitted from the optical engine 20 is incident on the coupling region 33, the first ray is coupled out to the pre-pupil waveguide 60, while the second ray in the image light is not coupled out and propagates directly within the optical waveguide 30 towards the coupling region 34. The second ray refers to the ray of image light that, after entering the optical waveguide 30, is not coupled out and propagates directly within the optical waveguide 30. During propagation, the second ray forms multiple first replicated light spots as it travels through the optical waveguide. Adjacent first replicated light spots are separate from each other; therefore, if only the second ray directly couples out from the coupling region 34 to form an image, a discontinuous pupil dilation problem will occur.

[0043] In this application, the first light ray after pupil dilation transmitted through the optical waveguide 30 in the coupling region 33 forms multiple second replicated light spots, with at least partial overlap between adjacent second replicated light spots. Thus, the second replicated light spots can form a continuous pupil dilation image after coupling out, thereby solving the technical problem of discontinuous pupil dilation in small exit pupil optical machines.

[0044] The display system 10 provided in this embodiment, by setting a pre-pupil waveguide 60, can rotate during operation. When the pre-pupil waveguide 60 is stationary, the first ray of the image light emitted from the optical engine 20 first passes through the coupling region 33 of the optical waveguide 30 and reaches the pre-pupil waveguide 60. The pre-pupil waveguide 60 performs one-dimensional pupil expansion on the first ray of the incident image light. The first ray after pupil expansion is coupled out to the coupling region 33 of the optical waveguide 30 and recoupled into the coupling region 33 of the optical waveguide 30. Since the pre-pupil waveguide 60 is also configured to rotate relative to the optical waveguide 30, the first ray recoupled into the optical waveguide 30 is incident at different positions in the coupling region 33. The two-dimensional pupil expansion effect is achieved through the time accumulation effect, while making the exit pupil continuous, thus solving the technical problem of discontinuous pupil expansion of small exit pupil optical engines. The entire display system 10 does not require increasing the size of the optical engine 20, nor does it require thinning of the optical waveguide 30. The volume of the entire display system 10 is controllable, and the manufacturing cost is lower.

[0045] Example 2 This embodiment provides a display system 10, which differs from Embodiment 1 in that the structure of the pre-pupil waveguide 60 is different. For the same parts, please refer to the relevant content in Embodiment 1, which will not be repeated here.

[0046] In this embodiment, see Figure 4 The pre-pupil waveguide 60 includes a driving device 61, a support member 62, and a waveguide element 65. The waveguide element 65 includes a first waveguide 63 and a second waveguide 64. The second waveguide 64 is disposed on the side of the first waveguide 63 facing away from the optical waveguide 30, and is connected to the support member 62. (See reference...) Figure 5 A one-dimensional grating 641 is disposed on the surface of the second waveguide 64 facing the first waveguide 63. Please refer to this for further details. Figure 4 and Figure 5 A one-dimensional grating 631 is disposed on the surface of the first waveguide 63 facing the optical waveguide 30, and the driving device 61 is used to drive the support member 62 to rotate. The orthographic projection of the one-dimensional grating 631 disposed on the first waveguide 63 onto the second waveguide 64 does not completely coincide with the one-dimensional grating 641 disposed on the second waveguide 64. The grating period and grating direction of the one-dimensional gratings on the first waveguide 63 and the second waveguide 64 are the same.

[0047] A gap 67 is formed between the first waveguide 63 and the second waveguide 64, and the gap 67 is filled with air. By filling the gap with air, the total internal reflection condition of the image light can be avoided. After the waveguide element 65 expands the pupil of the image light, all the image light can be reflected back to the optical waveguide 30.

[0048] Specifically, the surface of the second waveguide 64 facing the first waveguide 63 is provided with adhesive, the first waveguide 63 is adhered to the adhesive, and the adhesive is offset from the one-dimensional grating 641 provided on the second waveguide 64 to avoid obstructing the grating and improve the pre-pupil dilation efficiency.

[0049] The first ray of the image light emitted from the optical engine 20 enters the pre-pupil waveguide 60 through the coupling region 33 of the optical waveguide 30, and is then dilated by the first waveguide 63 and the second waveguide 64 in sequence. At least part of the first ray after pupil dilation is coupled out to the coupling region 33 and re-enters the optical waveguide 30 to propagate.

[0050] By setting the first waveguide 63 and the second waveguide 64, both the first waveguide 63 and the second waveguide 64 can perform one-dimensional pupil expansion on the image light at the same time. Therefore, the rotation speed of the driving device 61 can be reduced, but the pre-pupil expansion effect can be maintained at the same or similar level as in Embodiment 1.

[0051] Specifically, the first waveguide 63 and the second waveguide 64 can be arranged orthogonally, in which case the one-dimensional grating 631 disposed in the first waveguide 63 and the one-dimensional grating 641 disposed in the second waveguide 64 are also approximately orthogonal. This arrangement allows for a uniform distribution of the one-dimensional gratings, so that when the driving device 61 rotates, the first waveguide 63 and the second waveguide 64 can more uniformly expand the pupil of the image light.

[0052] The display system 10 provided in this embodiment, by setting a pre-pupil waveguide 60, can rotate during operation. When the pre-pupil waveguide 60 is stationary, the first ray in the image light emitted from the optical engine 20 first passes through the coupling region 33 of the optical waveguide 30 and reaches the pre-pupil waveguide 60. The pre-pupil waveguide 60 performs one-dimensional pupil expansion on the first ray in the incident image light. The first ray after pupil expansion is coupled out to the coupling region 33 of the optical waveguide 30 and recoupled into the coupling region 33 of the optical waveguide 30. Since the pre-pupil waveguide 60 is also configured to rotate relative to the optical waveguide 30, the first ray recoupled into the optical waveguide 30 is incident at different positions in the coupling region 33. The two-dimensional pupil expansion effect is achieved through the time accumulation effect, while making the exit pupil continuous, thus solving the technical problem of discontinuous pupil expansion of small exit pupil optical engines. The entire display system 10 does not require increasing the size of the optical engine 20, nor does it require thinning of the optical waveguide 30. The size of the entire display system 10 is controllable, and the manufacturing cost is lower. Due to the use of two layers of one-dimensional pre-pupil waveguide 60, the rotation speed of the drive device 61 can be lower while maintaining the same pre-pupil effect, which can reduce power consumption and alleviate heat dissipation pressure.

[0053] It should also be noted that in some other embodiments, the pre-pupil waveguide 60 may include a greater number of waveguides, but this embodiment does not limit this.

[0054] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions 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 this application, and should all be included within the protection scope of this application.

Claims

1. A display system, characterized in that, The system includes an optical engine, an optical waveguide, and a pre-pupil waveguide, both of which are located in the output optical path of the optical engine. The optical waveguide is positioned between the optical engine and the pre-pupil waveguide. Optical engine, which is used to output image light; An optical waveguide includes an input region and an output region. A first ray of image light passes through the input region of the optical waveguide and is incident on the pre-pupil waveguide. The pre-pupil waveguide is used to dilate at least a portion of the first ray and then output it in the direction of the input region. The pre-pupil waveguide is also configured to rotate relative to the optical waveguide so that the dilated first ray is incident on different positions of the input region at different times. At least a portion of the first light ray after pupil dilation is coupled into the optical waveguide by the coupling region, and the coupling-out region is used to couple out at least a portion of the image light transmitted in the optical waveguide.

2. The display system according to claim 1, characterized in that, The coupling region is also used to couple a second ray in the image light into the optical waveguide for transmission. When the second ray is transmitted in the optical waveguide, it forms a plurality of first replicated light spots, with adjacent first replicated light spots separated from each other.

3. The display system according to claim 2, characterized in that, The first light ray after pupil expansion transmitted through the optical waveguide coupled into the coupling region forms a plurality of second replicated light spots, and there is at least partial overlap between two adjacent second replicated light spots.

4. The display system according to claim 1, characterized in that, The pre-pupil waveguide includes a driving device, a support member, and a waveguide element. The waveguide element is connected to the support member. The driving device is used to drive the support member to rotate, thereby driving the waveguide element to rotate. A one-dimensional grating is provided on the waveguide element.

5. The display system according to claim 4, characterized in that, The waveguide element is configured to rotate about the optical axis of the optomechanism.

6. The display system according to claim 4, characterized in that, The support member has a first surface and a second surface that are disposed opposite to each other. The driving device is connected to the second surface of the support member. The waveguide is connected to the edge of the first surface of the support member. A gap is formed between the waveguide and the support member, and the gap is filled with air.

7. The display system according to claim 4, characterized in that, The support member is made of glass, and a reflective film is provided on the first or second surface of the support member; or; The support is a metal component, and the first surface of the metal component has a reflective function.

8. The display system according to claim 4, characterized in that, The waveguide element includes a first waveguide and a second waveguide. The second waveguide is disposed on the side of the first waveguide away from the optical waveguide and is connected to the support. A one-dimensional grating is disposed on the first waveguide and the second waveguide. The grating period and grating direction of the one-dimensional grating on the first waveguide and the one-dimensional grating on the second waveguide are the same.

9. The display system according to claim 8, characterized in that, An adhesive is provided on the surface of the second waveguide facing the first waveguide, the first waveguide is adhered to the adhesive, the adhesive is offset from the one-dimensional grating disposed on the second waveguide, and a gap is formed between the first waveguide and the second waveguide, the gap being filled with air.

10. The display system according to claim 9, characterized in that, The first waveguide and the second waveguide are arranged orthogonally.

11. The display system according to claim 4, characterized in that, The area of ​​the one-dimensional grating on the waveguide element is smaller than the area of ​​the coupling region. The waveguide element is rotated at least 360 degrees so that the first light rays emitted from the pre-pupil waveguide to the coupling region at different times after pupil expansion can fill the coupling region.

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