Optical engine for near-eye display and near-eye display device

Abstract

The invention provides an optical engine for near-eye display and near-eye display equipment, and relates to the technical field of augmented reality and virtual reality. The optical engine for near-to-eye display includes: a display chip for emitting image light; the metasurface lens assembly comprises a plurality of metasurface lens structures, and at least one metasurface lens structure in the plurality of metasurface lens structures is used for receiving image light transmitted from the display chip to the surface of the metasurface lens structure; the plurality of metasurface lens structures are installed on the deformation part, and the deformation part deforms under the condition that the deformation part is subjected to external force or electrified so as to drive the plurality of metasurface lens structures connected with the deformation part to change positions.

Description

Technical Field

[0001] The present disclosure relates to the technical fields of augmented reality and virtual reality, and in particular to an optical engine for near-eye display and a near-eye display device. Background Art

[0002] Augmented Reality (AR) is a technology that uses information provided by a computer system to increase the user's perception of the real world, applies virtual information to the real world, and superimposes computer-generated virtual objects and scenes onto real scenes, thereby enhancing reality. Virtual Reality (VR) uses information provided by a computer system to create a virtual world, such as presenting virtual objects and scenes.

[0003] Near-eye display is a display method for augmented reality and virtual reality devices, such as glasses or head-mounted display devices, which is a display method close to the eyes. In addition, the optical engine for near-eye display is an indispensable part of augmented reality or virtual reality devices. However, the visual convergence and accommodation conflict generated by the augmented reality or virtual reality system can cause dizziness and fatigue to the user (especially when the user wears it for a long time). Therefore, an optical engine for near-eye display that alleviates, reduces or eliminates the visual convergence and accommodation conflict is needed. Summary of the invention

[0004] The present disclosure provides an optical engine for near-eye display and a near-eye display device.

[0005] According to one aspect of the present disclosure, an optical engine for near-eye display is provided, and the optical engine for near-eye display includes: a display chip for emitting image light; a metasurface lens assembly, the metasurface lens assembly including: a plurality of metasurface lens structures, at least one of the plurality of metasurface lens structures being used to receive image light transmitted from the display chip to its surface; and a deformable member, the plurality of metasurface lens structures being mounted on the deformable member, wherein the deformable member is deformed when subjected to external force or when electrification is applied, so as to drive the plurality of metasurface lens structures connected to the deformable member to change their positions.

[0006] According to another aspect of the present disclosure, a near-eye display device is provided, and the near-eye display device includes: a carrier; and an optical engine as provided above according to the present disclosure, wherein the optical engine is disposed on the carrier.

[0007] According to one or more embodiments of the present disclosure, the display of multiple focal planes can be realized, and the multiple focal planes can provide depth information that is closer to the natural light field to alleviate, reduce or eliminate the visual convergence and accommodation conflict, thereby improving the wearing comfort of augmented reality and virtual reality devices.

[0008] These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in accordance with the present disclosure and should not be regarded as limiting the scope of the present disclosure.

[0010] Figure 1A-1B is a schematic diagram of an optical engine for near-eye display according to some embodiments of the present disclosure;

[0011] Figure 2 Schematic diagram of a metasurface lens imaging a light beam according to some embodiments of the present disclosure;

[0012] Figure 3 It is a schematic diagram of the structure of the liquid lens assembly of some embodiments of the present disclosure;

[0013] Figure 4 It is a schematic diagram of the structure of the electrodeformable body in some embodiments of the present disclosure;

[0014] Figure 5 Schematic diagram of an optical engine for near-eye display according to some other embodiments of the present disclosure;

[0015] Figure 6 This is a three-dimensional structural diagram of a near-eye display device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0016] In the present disclosure, unless otherwise specified, the use of the terms "first", "second", etc. to describe various elements is not intended to limit the positional relationship, timing relationship, or importance relationship of these elements, and such terms are only used to distinguish one element from another element. In some examples, the first element and the second element may refer to the same instance of the element, and in some cases, based on the description of the context, they may also refer to different instances.

[0017] The terms used in the description of various examples described in this disclosure are only for the purpose of describing specific examples and are not intended to be limiting. Unless the context clearly indicates otherwise, if the number of elements is not specifically limited, the element can be one or more. As used herein, the term "plurality" means two or more, and the term "based on" should be interpreted as "based at least in part on". In addition, the terms "and / or" and "at least one of..." cover any one of the listed items and all possible combinations.

[0018] Near-eye display is used to form a distant virtual image close to the eye and project it into the human eye. In the current optical engine for near-eye display, visual convergence and accommodation conflict is the biggest technical problem in augmented reality and virtual reality, which seriously affects the user experience. Among them, visual convergence and accommodation conflict refers to the conflict between the distance information of the observed target reflected by the convergence of the human eye and the accommodation of the lens. Human eye convergence refers to the degree of convergence of the eyeball when a person observes a target with both eyes, and lens accommodation refers to the focus of the lens adjustment when the human eye observes the target to ensure that the retina receives a clear image. Existing augmented reality and virtual reality devices are all by displaying pictures of the same object taken from different angles to the left and right eyes, and using the image offset seen by both eyes to present a three-dimensional feeling, but these pictures do not have depth information, so the focus adjustment of the eyes does not match the depth sense, and the convergence of the human eye still truly reflects the distance information of the virtual target, resulting in visual convergence and accommodation conflict. In order to solve the visual convergence and accommodation conflict, the relevant technology proposes to provide depth information closer to the natural light field through multiple focal planes, thereby alleviating the visual convergence and accommodation conflict.

[0019] However, existing multi-focal plane display systems have disadvantages such as complex structure, large size and weight, which are not convenient for manufacturing augmented reality or virtual reality devices.

[0020] In order to effectively reduce the volume and weight of an optical engine while realizing multi-focal plane display, the present disclosure provides an optical engine for near-eye display.

[0021] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0022] Figure 1A-1B is a schematic diagram of an optical engine 100 for near-eye display according to some embodiments of the present disclosure; Figure 2 Schematic diagram of imaging a light beam by a metasurface lens according to some embodiments of the present disclosure.

[0023] refer to Figure 1A and Figure 1B , an optical engine 100 for near-eye display includes a display chip 110 and a metasurface lens assembly 120. The display chip 110 is used to emit image light. The metasurface lens assembly 120 includes a plurality of metasurface lens structures 130 and a deformable member 140. At least one of the plurality of metasurface lens structures 130 is used to receive image light transmitted from the display chip 110 to its surface. The plurality of metasurface lens structures 130 are mounted on the deformable member 140. The deformable member 140 is deformed when subjected to external force or energized, so as to drive the plurality of metasurface lens structures 130 connected to the deformable member 140 to change position.

[0024] like Figure 1A and Figure 1B As shown in , the display chip 110 is used to generate and modulate two image light groups, and transmit the two image light groups to the metasurface lens assembly 120 located downstream of the display chip 110. Figure 1A The deformable member 140 of the metasurface lens assembly 120 does not deform. Figure 1B The deformable member 140 of the metasurface lens assembly 120 in the embodiment is deformed, and the positions of the multiple metasurface lens structures 130 connected to the deformable member 140 are also changed. Figure 1A and Figure 1B It can be seen from the comparison that due to Figure 1B The positions of the multiple metasurface lens structures 130 in the embodiment change, so the incident angles of the image light coupled into some of the multiple metasurface lens structures 130 also change, and thus the exit angles of the image light emitted from the metasurface lens structures 130 change ( Figure 1B The image light emitted from the multiple metasurface lens structures 130 is obviously more concentrated and converged).

[0025] According to some embodiments of the present application, the metasurface lens structure 130 may include a phase compensation structure. The phase compensation structure is formed by a dielectric material. According to some embodiments of the present application, the phase compensation structure may include a solid micro-nano structure such as a cuboid, a column, a hemisphere, or a hollow or partially hollow micro-nano structure having a concave or hole of a cuboid, a column, or a hemisphere.

[0026] For details about the principle of combining multiple metasurface lens structures 130 with the deformable member 140 and applying them to the optical engine 100 for near-eye display, please refer to Figure 2 .like Figure 2 As shown, multiple metasurface lens structures 130 are coupled (for simplicity, multiple metasurface lens structures 130 are regarded as an integral structure, which is represented as Figure 2 The relationship between the phase of the image light of the rectangular structure 130 in FIG. 1 and the incident angle and the focal length f is as follows:

[0027]

[0028] Wherein, λ is the wavelength, f is the distance between the sensor 170 and the multiple metasurface lens structures 130 (i.e., the focal length), f' is the distance traveled by the main light of the image light passing through the center points of the multiple metasurface lens structures 130 from the multiple metasurface lens structures 130 to the sensor 170, Δr is the distance from one of the multiple metasurface lens structures 130 to the intersection of the main light and the multiple metasurface lens structures 130, and θ=arccos(f / f').

[0029] It can be seen that the focal length f determines the exit angle of the image light emitted from the multiple metasurface lens structures 130, that is, the deflection angle of the exit light. In other words, Relation 1 can also characterize the relationship between the phase of the incident light, the incident angle of the incident light, the exit angle of the exit light, and the radial distance from the metasurface lens structure 130 to the center point. Therefore, even if the phase of the incident light remains unchanged, the exit angle of the exit light can be changed by changing the incident angle of the incident light or by changing the radial distance from the metasurface lens structure 130 to the center point.

[0030] According to an embodiment of the present disclosure, a plurality of metasurface lens structures 130 are used to realize multi-focal plane display, and are combined with a deformable member 140 (the shape of the deformable member 140 can be changed) and applied in an optical engine of a near-eye display, which can effectively reduce the volume and weight of the optical engine, thereby making the overall structure more compact.

[0031] Continue to refer to Figure 1A and Figure 1B The optical engine 100 may further include an aperture 150 . The aperture 150 is aligned with the metasurface lens assembly 120 to limit the image light emitted through the metasurface lens assembly 120 .

[0032] The reason why an aperture is set to limit the image light emitted through the metasurface lens assembly 120 in the optical system is that the image light is often surrounded by stray light. In order to eliminate the influence of stray light on the subsequent optical path, an aperture needs to be added to the optical path to block the stray light and allow the main beam of the image light to pass through.

[0033] exist Figure 1A and Figure 1B In the example shown, the metasurface lens assembly 120 is located in the emission path of the display chip 110. At least one of the multiple metasurface lens structures 130 is used to receive the image light emitted by the display chip 110, and the multiple metasurface lens structures 130 are mounted on the first side of the deformable member 140, and the first side faces the image light emitted by the display chip 110. In other words, the multiple metasurface lens structures 130 are arranged closer to the display chip 110 than the deformable member 140. Although Figure 1A and Figure 1B It is shown that multiple super-surface lens structures 130 are installed on the first side of the deformable member 140, but it can be understood that multiple super-surface lens structures 130 can also be installed on the second side of the deformable member 140, the second side is away from the image light emitted by the display chip 110, or multiple super-surface lens structures 130 can also be installed on both sides of the deformable member 140, and the present disclosure does not limit this.

[0034] According to some embodiments of the present application, the position change of the plurality of metasurface lens structures 130 includes at least one of the following: at least one of the plurality of metasurface lens structures 130 is bent or the spacing between at least two of the plurality of metasurface lens structures 130 is changed. Figure 1B In the example shown, the deformable member 140 of the metasurface lens assembly 120 is bent (convexly bent toward the image light emitted via the display chip 110), and the multiple metasurface lens structures 130 connected to the deformable member 140 are also bent. In some embodiments, the change in the spacing between at least two of the multiple metasurface lens structures 130 includes at least one of an increase or decrease in the spacing between at least two metasurface lens structures. As described above, changing the incident angle of the incident light can be achieved by bending the metasurface lens structure, while changing the radial distance of the metasurface lens structure 130 from the center point can be achieved by changing the spacing between at least two metasurface lens structures. In short, the use of the deformable member 140 can change the relative positional relationship of the metasurface lens structure 130 (whether bending or spacing change), thereby realizing the zoom imaging function of the optical engine 100.

[0035] According to some embodiments of the present application, the display chip 110 includes at least one of an active light-emitting optical display chip or a passive light-emitting optical display chip. For example, the display chip 110 may be an active light-emitting optical display chip such as Micro LED, Micro OLED, LCD, etc. For another example, the display chip 110 may also be a passive light-emitting optical display chip such as DLP, LCOS, etc. (a light source illumination system needs to be added to the structure). In some embodiments, the display chip 110 is a chip that can provide monochrome or full-color image information.

[0036] According to some embodiments of the present application, in order to realize real-time display of multiple focal planes, each focal plane needs to have at least 30 frames of images per second. For example, if n display focal planes are required. For monochrome image display, the image refresh rate of the display chip 110 needs to be at least 30n frames, and the frequency of the deformable member 140 is the same as the frame rate of the display chip 110, both of which are 30n frames. For color display, since the structure of the metasurface lens structure 130 is a function of the wavelength, it needs to be displayed separately. At this time, the image refresh rate of the display chip 110 needs to be at least 90n frames, and the frequency of the deformable member 140 is the same as the frame rate of the display chip 110, which is 90n frames. When the frequencies of the display chip 110 and the deformable member 140 are sufficient, infinite multiple focal planes can be achieved in theory.

[0037] Further references Figure 3 . Figure 31 is a schematic diagram of the structure of a liquid lens assembly 300 according to some embodiments of the present disclosure. The deformable member 140 may include a liquid lens assembly 300. The liquid lens assembly 300 is deformed when subjected to an external force, so as to drive the multiple metasurface lens structures 130 connected to the liquid lens assembly 300 to change their positions. Figure 3 As shown, the liquid lens assembly 300 includes a film 310 and a liquid 320. The film 310 is deformable and light-transmissive, wherein the film 310 encloses a cavity 330. The liquid 320 is filled in the cavity 330.

[0038] exist Figure 3 In the example shown, the frame 340 is used to fix the upper and lower films 310 respectively, so that the two films 310 enclose a cavity 330 for containing the liquid 320. In some embodiments, an actuator (not shown) can be connected to the liquid lens assembly 300 to contact and compress at least one of the two deformable films 310 to deform.

[0039] although Figure 3 It is shown that the liquid lens assembly 300 can have two layers of film 310, namely, an upper film and a lower film, but it can be understood that the liquid lens assembly 300 can also have only one layer of film 310, namely, an upper film or a lower film, and the present disclosure does not limit this.

[0040] According to some embodiments of the present application, the film 310 may refer to an elastic transparent film that can be deformed arbitrarily. In a possible implementation, the film 310 may be a PDMS (polydimethylsiloxane) film, which is not limited in the present embodiment. According to some embodiments of the present application, the liquid 320 may be an optical liquid. When selecting the optical liquid, any desired optical liquid with a specific refractive index and dispersion characteristics may be selected as needed, provided that the optical liquid does not have a negative effect (such as a chemical reaction) with the film 310. The present embodiment does not limit the liquid 320.

[0041] By wrapping the liquid 320 in the film 310, the liquid lens assembly 300 can be deformed when subjected to external force, thereby causing the multiple metasurface lens structures 130 connected to the liquid lens assembly 300 to change position. The design is ingenious and the structure is compact, so the entire optical engine 100 can be compact.

[0042] Further references Figure 4 . Figure 41 is a schematic diagram of the structure of the electrodeformer 400 of some embodiments of the present disclosure. The deformable member 140 may include the electrodeformer 400. The electrodeformer 400 deforms when powered, so as to drive the multiple metasurface lens structures 130 connected to the liquid lens assembly 300 to change their positions. Figure 4 As shown, the electrodeformable body 400 includes a piezoelectric block 410 and a wire 420. The wire 420 is used to connect to an external power source to energize the piezoelectric block 410.

[0043] exist Figure 4 In the example shown, two wires 420 are provided on the piezoelectric block 410, one of which is connected to the positive electrode of the power supply, and the other is connected to the negative electrode of the power supply. A voltage signal is applied to the piezoelectric block 410 through the power supply and the wires 420 to drive the piezoelectric block 410 to deform.

[0044] Specifically, the deformation effect of the piezoelectric block 410 is caused by the rearrangement of the electric dipole moment inside the electro-induced material under the action of the external electric field. When the external electric field acts on the electro-induced material, the positive and negative charges inside the material will be offset, resulting in the generation of electric dipole moments. These electric dipole moments will interact with the external electric field to cause deformation of the material.

[0045] The piezoelectric block 410 is deformed under the action of an external electric field, which can drive the multiple metasurface lens structures 130 connected to the electrodeformer 400 to change position. The design is ingenious and the structure is compact, so the entire optical engine 100 can be compact.

[0046] Further references Figure 5 . Figure 5 Schematic diagram of an optical engine 500 for near-eye display in some other embodiments of the present disclosure. In some embodiments, the optical engine 500 may further include an optical waveguide 510. The optical waveguide 510 is used to guide the image light emitted by the display chip 110 to the metasurface lens assembly 120. In some embodiments, the optical engine 500 may further include an optical lens group 520. The optical lens group 520 is used to shape the image light emitted by the display chip 110, and is opposite to the input end 530 of the optical waveguide 510, so that the shaped image light can enter the input end 530 of the optical waveguide 510.

[0047] exist Figure 5In the example shown, the optical lens group 520 is arranged in the emission path of the display chip 110. The optical waveguide 510 includes an input end 530 and an output end 540. The input end 530 is arranged in the emission path of the display chip 110, and is used to receive the image light shaped by the optical lens group 520, confine the image light in the channel of the optical waveguide 510 by total internal reflection, and emit the shaped image light at the output end 540. The metasurface lens assembly 120 is opposite to the output end 540 of the optical waveguide 510 to receive the image light emitted from the optical waveguide 510. The metasurface lens assembly 120 includes a plurality of metasurface lens structures 130 and a deformable member 140. At least one of the plurality of metasurface lens structures 130 is used to receive the image light emitted from the optical waveguide 510. The plurality of metasurface lens structures 130 are mounted on a first side of the deformable member, and the first side faces the image light emitted from the optical waveguide 510. The deformable member 140 is deformed when subjected to external force or powered on, so as to drive the positions of the multiple metasurface lens structures 130 connected to the deformable member 140 to change.

[0048] It should be understood that in addition to the features described above, other features of the optical engine 500 (e.g., the display chip 110, the metasurface lens assembly 120, etc.) can be used in conjunction with Figure 1A-1B The corresponding features of the optical engine 100 described in are the same and will not be described in detail here for the sake of brevity.

[0049] Further references Figure 6 . Figure 6 FIG. 6 is a three-dimensional structural diagram of a near-eye display device 600 according to some embodiments of the present disclosure. Figure 6 As shown, a near-eye display device 600 (e.g., augmented reality glasses) includes a carrier 610. The carrier 610 may include a frame 620 and a lens 630. The optical engine 100, 500 may be disposed on the carrier 610. According to some embodiments of the present application, the optical engine 100, 500 may be disposed on the carrier 610 in a laminated manner, or may be disposed in the carrier 610 as an interlayer. The present disclosure does not particularly limit the manner in which the optical engine 100, 500 is disposed on the carrier 610.

[0050] The embodiment of the present disclosure manufactures a near-eye display device 600 by adopting a metasurface lens structure in conjunction with a multi-focal plane display system of a deformable part, and arranges the optical engines 100 and 500 on a carrier 610, so that the near-eye display device 600 has a simple structure, a small size and is lightweight, making the near-eye display device 600 similar to the glasses that users wear daily, which helps to improve the user experience.

[0051] Although the present disclosure has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description should be considered illustrative and schematic, not restrictive; the present disclosure is not limited to the disclosed embodiments. By studying the drawings, the disclosure and the appended claims, those skilled in the art will be able to understand and implement variations to the disclosed embodiments when practicing the claimed subject matter. In the claims, the word "comprising" does not exclude other elements or steps that are not listed, the indefinite article "a" or "an" does not exclude a plurality, the term "plurality" means two or more, and the term "based on" should be interpreted as "based at least in part on". The mere fact that certain measures are recorded in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. An optical engine for near-eye display, comprising: Display chip, used to emit image light; A metasurface lens assembly, the metasurface lens assembly comprising: a plurality of metasurface lens structures, at least one of the plurality of metasurface lens structures being used to receive image light transmitted from the display chip to its surface; and A deformable member, wherein the multiple super-surface lens structures are mounted on the deformable member, wherein the deformable member is deformed when subjected to external force or energized, so as to drive the multiple super-surface lens structures connected to the deformable member to change their positions.

2. The optical engine according to claim 1, further comprising: An aperture is aligned with the metasurface lens assembly and is used to limit the image light emitted through the metasurface lens assembly.

3. The optical engine according to claim 1 or 2, wherein: The position change of the multiple super-surface lens structures includes at least one of the following: at least one super-surface lens structure among the multiple super-surface lens structures is bent or the spacing between at least two super-surface lens structures among the multiple super-surface lens structures changes.

4. The optical engine according to claim 1 or 2, wherein: The deformable member includes a liquid lens assembly, and the liquid lens assembly is deformed when subjected to an external force, so as to drive the multiple super-surface lens structures connected to the liquid lens assembly to change their positions.

5. The optical engine according to claim 4, wherein: The liquid lens assembly comprises: A film, the film is deformable and light-transmissive, wherein the film encloses a cavity; and A liquid is filled in the cavity.

6. The optical engine according to claim 1 or 2, wherein: The deformable member includes an electro-deformable body, which deforms when powered on to drive the multiple metasurface lens structures connected to the liquid lens assembly to change their positions.

7. The optical engine according to claim 6, wherein: The electrodeformable body comprises: Piezoelectric blocks; and The wire is used to connect to an external power source to supply power to the piezoelectric block.

8. The optical engine according to claim 1 or 2, characterized in that: The display chip includes at least one of an active light-emitting optical display chip or a passive light-emitting optical display chip.

9. The optical engine according to claim 1 or 2, wherein: The metasurface lens assembly is located in the emission path of the display chip, at least one of the multiple metasurface lens structures is used to receive the image light emitted by the display chip, and the multiple metasurface lens structures are installed on the first side of the deformable member, and the first side faces the image light emitted by the display chip.

10. The optical engine according to claim 1 or 2, further comprising: An optical waveguide is used to guide the image light emitted by the display chip to the metasurface lens assembly.

11. The optical engine according to claim 10, further comprising: The optical lens group is used to shape the image light emitted by the display chip and is opposite to the input end of the optical waveguide so that the shaped image light can enter the input end of the optical waveguide.

12. The optical engine according to claim 11, wherein: The optical lens group is arranged on the emission path of the display chip. The optical waveguide includes an input end and an output end. The input end is arranged in the emission path of the display chip, and is used to receive the image light shaped by the optical lens group, confine the image light in the channel of the optical waveguide through total internal reflection, and emit the shaped image light at the output end. The metasurface lens component is opposite to the output end of the optical waveguide to receive the image light emitted from the optical waveguide, and the metasurface lens component includes: a plurality of metasurface lens structures, at least one of the plurality of metasurface lens structures being used to receive image light emitted from the optical waveguide; and A deformable member, wherein the multiple metasurface lens structures are mounted on a first side of the deformable member, the first side faces the image light emitted from the optical waveguide, wherein the deformable member is deformed when subjected to an external force or energized to drive the multiple metasurface lens structures connected to the deformable member to change their positions.

13. A near-eye display device, characterized in that: include: Carrier; as well as At least one optical engine according to any one of claims 1 to 12, wherein the optical engine is arranged on the carrier.

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