Devices and Systems for Augmented Reality Display

Abstract

The present invention relates to image display technology, and particularly to a device for augmented reality display and a system for implementing augmented reality display including the device. The device for augmented reality display includes: a waveguide lens; first to third optical functional structures disposed on the surface of the waveguide lens, wherein the second optical functional structure is located between the first optical functional structure and the third optical functional structure, and light incident on the first optical functional structure forms a first light beam and a second light beam under the action of the first optical functional structure. The first and second light beams are propagated in the waveguide lens by total reflection to the second optical functional structure, and under the action of the second optical functional structure, the first and second light beams are propagated in the waveguide lens by total reflection to the third optical functional structure and are emitted after being fused by the third optical functional structure.

Description

Technical Field

[0001] The present invention relates to image display technology, and particularly to a device for augmented reality display and a system for implementing augmented reality display including the device. Background Art

[0002] Augmented reality (AR) technology is a new type of display technology that "seamlessly" integrates real-world information and virtual-world information. It not only presents real-world information but also simultaneously displays virtual information, thus realizing the mutual complementation and superposition of the two types of information. In visual augmented reality, a head-mounted display is used to present a mixed image that superimposes the real world and computer-generated virtual images to the user.

[0003] Currently, most mainstream near-eye augmented reality display devices adopt the principle of optical waveguide. For example, in a typical augmented reality display device, the image on a microdisplay spatial light modulator (such as LCOS) is coupled to an optical waveguide through three holographic gratings, and then transmitted through three optical waveguides respectively. Finally, it is coupled and output through corresponding holographic gratings directly in front of the human eye for projection onto the human eye. To achieve color projection, a multi-layer optical waveguide method can be used. However, augmented reality display devices based on the above working principle have multiple drawbacks. For example, the efficiency is uneven within the field of view, resulting in uneven display brightness, thus affecting the experience effect. Summary of the Invention

[0004] An object of the present invention is to provide a device for augmented reality display, which has advantages such as good uniformity of light expansion efficiency within the exit pupil range and simple structure.

[0005] The device for augmented reality display according to one aspect of the present invention includes:

[0006] An optical waveguide lens; and

[0007] A first optical functional structure, a second optical functional structure, and a third optical functional structure provided on the surface of the optical waveguide lens,

[0008] wherein the second optical functional structure is located between the first optical functional structure and the third optical functional structure,

[0009] Among them, the light incident on the first optical functional structure forms a first light beam and a second light beam under the action of the first optical functional structure. Among them, the first light beam propagates to the second optical functional structure in the optical waveguide lens by total internal reflection, and the second light beam propagates to the second optical functional structure in the optical waveguide lens by total internal reflection. And under the action of the second optical functional structure, the first light beam and the second light beam propagate to the third optical functional structure in the optical waveguide lens by total internal reflection, and are emitted after being fused by the third optical functional structure.

[0010] Preferably, in the above device, the propagation paths of the first light beam and the second light beam in the optical waveguide lens are symmetric with respect to a reference axis, and the reference axis is perpendicular to the horizontal axis of the device.

[0011] Preferably, in the above device, the first optical functional structure, the second optical functional structure, and the third optical functional structure are symmetrically arranged on the surface of the optical waveguide lens with respect to the reference axis, and the second optical functional structure is located between the first optical functional structure and the third optical functional structure.

[0012] Preferably, in the above device, the first optical functional structure and the third optical functional structure are two-dimensional gratings, and the second optical functional structure is a one-dimensional grating, and the one-dimensional grating is configured to make the first light beam and the second light beam enter the third optical functional structure at symmetric incident angles with respect to the reference axis.

[0013] Preferably, in the above device, the first optical functional structure, the second optical functional structure, and the third optical functional structure are symmetrically arranged on the surface of the optical waveguide lens with respect to the reference axis. The second optical functional structure includes a first sub-structure and a second sub-structure symmetrically located between the first optical functional structure and the third optical functional structure, and the first light beam and the second light beam respectively propagate to the first sub-structure and the second sub-structure.

[0014] Preferably, in the above device, the first optical functional structure and the third optical functional structure are two-dimensional gratings, and the first sub-structure and the second sub-structure are one-dimensional gratings, which are configured to make the first light beam and the second light beam enter the third optical functional structure at symmetric incident angles with respect to the reference axis.

[0015] Preferably, in the above device, the first optical functional structure, the second optical functional structure, and the third optical functional structure are located on the same surface of the optical waveguide lens.

[0016] Preferably, in the above device, the one-dimensional grating is one of the following: tilted grating, rectangular grating, blazed grating, and volume grating. Another object of the present invention is to provide a system for realizing augmented reality display, which has advantages such as good balance of light expansion efficiency within the exit pupil range and simple structure.

[0017] Preferably, in the above device, the total phase of the first optical function, the second optical function structure, and the third optical function structure is zero to satisfy phase matching.

[0018] Preferably, in the above device, the two-dimensional gratings used as the first optical function structure and the third optical function structure have the same structural parameters.

[0019] Preferably, in the above device, the period of the two-dimensional grating is in the range of 300 - 600 nm.

[0020] Preferably, in the above device, the period of the one-dimensional grating used as the second optical function structure is set to √2 / 2 times the grating period of the first optical function structure.

[0021] A system for realizing augmented reality display according to another aspect of the present invention includes:

[0022] An image source configured to provide light containing image information; and

[0023] An image presentation device, including:

[0024] An optical waveguide lens; and

[0025] A first optical function structure, a second optical function structure, and a third optical function structure disposed on the surface of the optical waveguide lens,

[0026] wherein the second optical function structure is located between the first optical function structure and the third optical function structure,

[0027] wherein the incident light from the image source forms a first light beam and a second light beam under the action of the first optical function structure. Among them, the first light beam propagates in the optical waveguide lens by total internal reflection to the second optical function structure, and the second light beam propagates in the optical waveguide lens by total internal reflection to the second optical function structure. And under the action of the second optical function structure, the first light beam and the second light beam propagate in the optical waveguide lens by total internal reflection to the third optical function structure and are emitted after being fused by the third optical function structure.

[0028] wherein the propagation paths of the first light beam and the second light beam in the optical waveguide lens are set to be symmetric.

[0029] According to an embodiment of the present invention, the light entering the image display device is separated into a first light beam and a second light beam. The propagation paths of the first and second light beams before reaching the decoupling element are symmetric, whereby a symmetric expansion of the field of view range can be achieved, thus providing good balance. In addition, the image presentation device according to the above embodiment of the present invention has a simple and compact structure, which is beneficial to reducing the overall size of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1A and 1B are respectively a top view and a perspective view of a device for presenting an image according to an embodiment of the present invention.

[0031] Figure 2A and 2B are respectively a top view and a perspective view of a device for presenting an image according to another embodiment of the present invention.

[0032] Figure 3A is Figure 1A and 1B a schematic diagram of the effective visible area of the device for augmented reality display shown in the embodiments. Figure 3B is Figure 2A and 2B a schematic diagram of the effective visible area of the device for augmented reality display shown in the embodiments.

[0033] Figures 4A - 4C shows an example of a one-dimensional grating applicable to Figure 1A and 1B and Figure 2A and 2B the embodiments shown.

[0034] Figure 5 shows an example of a two-dimensional grating applicable to Figure 1A and 1B and Figure 2A and 2B the embodiments shown.

[0035] Figure 6 shows the relationship curve between the incident angle of blue light and the transmission efficiency in the device for augmented reality display shown in Figure 1A and 1B and Figure 2A and 2B the embodiments shown.

[0036] Figure 7 shows the relationship curve between the incident angle of green light and the transmission efficiency in the device for augmented reality display shown in Figure 1A and 1B and Figure 2A and 2B the embodiments shown.

[0037] Figure 8 shows the relationship curve between the incident angle of red light and the transmission efficiency in the device for augmented reality display shown in Figure 1A and 1B as well as Figure 2A and 2B Figure 10 shows the relationship curve between the incident angle of red light and the transmission efficiency in the device for augmented reality display shown in Figures 10A, 10B, 10C, 10D, and 10E.

[0038] Figure 9 FIG. 11 is a schematic diagram of a system for implementing augmented reality display according to another embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The above-described embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0040] In this specification, terms such as "comprising" and "including" mean that the technical solutions of the present invention do not exclude the presence of other elements and steps that are not directly or explicitly recited in the specification and claims, in addition to the elements and steps that are directly and explicitly recited.

[0041] Terms such as "first" and "second" do not denote an order of the elements in terms of time, space, size, etc., but are merely used to distinguish the elements from each other.

[0042] According to one aspect of the present invention, light entering an image display device is separated into a first light beam and a second light beam, and the propagation paths of the first and second light beams before reaching the coupling-out element are symmetric, whereby a symmetric expansion of the field of view can be achieved, thus providing good balance. In one or more embodiments of the present invention, the propagation paths of the first and second light beams in the image display device are symmetric with respect to a reference axis, which is perpendicular to the horizontal axis of the image display device (for example, for a waveguide lens, the horizontal axis is the axis along the left-right direction).

[0043] Figure 1A and 1B FIGS. 12A and 12B are a top view and a perspective view, respectively, of a device for presenting an image according to an embodiment of the present invention. Exemplarily, the device for augmented reality display in this embodiment may be in the form of glasses lenses.

[0044] See Figure 1A and 1B, the device 10 for augmented reality display in this embodiment includes a waveguide lens 110 and a first optical functional structure 121, a second optical functional structure 122, and a third optical functional structure 123 disposed on the surface of the waveguide lens. In Figure 1A and 1B , the coordinate axis X is parallel to the horizontal axis of the device or the field of view, the coordinate axis Y is parallel to the thickness direction of the waveguide lens, and the coordinate axis Z is perpendicular to the horizontal axis of the device or the field of view.

[0045] Optionally, the first optical functional structure 121, the second optical functional structure 122, and the third optical functional structure 123 are nanostructures for diffracting incident light. Additionally, optionally, these optical functional structures are located on the same surface of the waveguide lens 110 or on different surfaces of the waveguide lens 110.

[0046] In Figure 1A and 1B shown in the embodiment, the first optical functional structure 121 is disposed at the center of the upper region of the surface of the waveguide lens, and is configured to couple the incident light A into the waveguide lens 110, so it can also be called the coupling-in region. The incident light enters the first optical functional structure 121 at a certain incident angle, and forms a first light beam and a second light beam under the diffraction effect of the first optical functional structure 121. In this embodiment, the light A incident on the first optical functional structure 121 can be light of a single wavelength or can include multiple bands (such as a red light component, a blue light component, and a green light component). For the case of multiple bands, through appropriate optical design of the first optical functional structure 121 (such as designing the first optical functional structure in the form of a two-dimensional grating), the formed first and second light beams can have the same band or spectrum.

[0047] See Figure 1B , the first light beam and the second light beam propagate in the waveguide lens 110 along the first path A21 and the second path A22 respectively. By means of appropriate design of the first optical functional structure 121, the incident light can form a first light beam and a second light beam with propagation paths symmetric with respect to a reference axis (such as Figure 1A axis T perpendicular to the coordinate axis X in the X-Z plane in

[0048] It should be noted that, in this embodiment, when light beam A is a single-wavelength light beam, the first light beam and the second light beam will propagate in directions symmetric with respect to the reference axis; for the multi-band case, the light components with the same wavelength in the first light beam and the second light beam will propagate in directions symmetric with respect to the reference axis. In this specification, expressions such as the propagation path is symmetric with respect to the reference axis or similar should be understood to include the above two cases.

[0049] Continue to refer to Figure 1A and 1B , the second optical functional structure 122 and the third optical functional structure 123 are respectively arranged in the middle area and the lower area on the surface of the optical waveguide lens 110, that is to say, the second optical functional structure 122 is located between the first optical functional structure 121 and the third optical functional structure 123.

[0050] As Figure 1B shown, the first light beam and the second light beam propagate in paths A21 and A22 symmetric with respect to the reference axis T in the optical waveguide lens 110, and reach the second optical functional structure 122 after total reflection. By means of a suitable design of the second optical functional structure 122, the first light beam and the second light beam can continue to propagate in two paths B21 and B22 symmetric with respect to the reference axis T in the optical waveguide lens 110 in a total reflection manner to the third optical functional structure 123 under the diffraction action of the second optical functional structure 122. Since the second optical functional structure 122 changes the propagation directions of the first light beam and the second light beam, it can also be called a turning area.

[0051] In Figure 1A and 1B the shown embodiment, the third optical functional structure 123 is configured to make the first light beam and the second light beam merge and then exit from the optical waveguide lens 110 along the Y axis, so as to present an augmented reality image to the user. Therefore, the third optical functional structure 123 can also be called an output area.

[0052] It should be noted that Figure 1A and 1B the positions of the first to third optical functional structures on the optical waveguide lens shown are only exemplary. In fact, other structures and arrangement methods that can symmetrically expand the incident light are also feasible. Figure 2A and 2B are respectively the top view and the three-dimensional view of the device for presenting an image according to another embodiment of the present invention. Exemplarily, the device for augmented reality display in this embodiment can be in the form of spectacle lenses.

[0053] Refer to Figure 2A and 2B, the device 20 for augmented reality display in this embodiment includes a waveguide lens 210 and a first optical functional structure 221, a second optical functional structure 222, and a third optical functional structure 223 disposed on the surface of the waveguide lens. In Figure 2A and 2B , the coordinate axis X is parallel to the horizontal axis of the device or the field of view, the coordinate axis Y is parallel to the thickness direction of the waveguide lens, and the coordinate axis Z is perpendicular to the horizontal axis of the device or the field of view.

[0054] Optionally, the first optical functional structure 221, the second optical functional structure 222, and the third optical functional structure 223 are nanostructures for diffracting incident light. Additionally, optionally, these optical functional structures are located on the same surface of the waveguide lens 210 or on different surfaces of the waveguide lens 210.

[0055] In Figure 2A and 2B In the illustrated embodiment, the first optical functional structure or the coupling-in region 221 is disposed at the center of the upper region of the surface of the waveguide lens, and is configured to couple the incident light A' into the waveguide lens 210. The incident light enters the first optical functional structure 221 at a certain incident angle, and forms a first light beam and a second light beam through the diffraction of the first optical functional structure 221. Among them, the first light beam and the second light beam propagate in the waveguide lens 210 along the first path A21' and the second path A22', respectively. By means of a suitable design of the first optical functional structure 221, the incident light can be diffracted by the first optical functional structure 221 to form a first light beam and a second light beam whose propagation paths are symmetric with respect to a reference axis (for example Figure 2A the axis T' perpendicular to the coordinate axis X in the X-Z plane in

[0056] Continuing to refer to Figure 2A and 2B , the second optical functional structure 122 and the third optical functional structure 223 are respectively disposed in the middle region and the lower region of the surface of the waveguide lens 210. That is to say, the second optical functional structure 222 is located between the first optical functional structure 221 and the third optical functional structure 223. However, different from the embodiments shown in Figure 1A and 1B , the second optical functional structure 222 includes discrete first sub-structure 222A and second sub-structure 222B, wherein the first sub-structure 222A is disposed at the lower left of the first optical functional structure 221, and the second sub-structure 222B is disposed at the lower right of the first optical functional structure 221.

[0057] As shown in Figure 2BAs shown, the first light beam and the second light beam propagate in the optical waveguide lens 210 along paths A21' and A22' that are symmetric with respect to the reference axis T', and reach the first sub-structure 222A and the second sub-structure 222B through total internal reflection respectively. By means of a suitable design of the first sub-structure 222A and the second sub-structure 222B, the first light beam and the second light beam can continue to propagate along two paths B21' and B22' that are symmetric with respect to the reference axis T' under the diffraction effect of the first sub-structure 222A and the second sub-structure 222B, and propagate in the optical waveguide lens 210 to the third optical functional structure 223 in a total internal reflection manner. Similarly, the second optical functional structure 222 can also be referred to as a turning region.

[0058] In Figure 2A and 2B In the illustrated embodiment, the third optical functional structure 223 or the coupling-out region is configured to cause the first light beam and the second light beam to fuse and then exit from the optical waveguide lens 210 along the Y-axis, thereby presenting an augmented reality image to the user.

[0059] In this embodiment, the light ray A' incident on the first optical functional structure 221 can be a light ray of a single wavelength, or can include multiple bands (such as a red light component, a blue light component, and a green light component). For the case of multiple bands, through a suitable optical design of the first optical functional structure 221 (such as designing the first optical functional structure in the form of a two-dimensional grating), the formed first and second light beams can have the same band or spectrum, and expressions such as the propagation paths being symmetric with respect to the reference axis should also be understood to include the cases of a single wavelength and multiple bands.

[0060] Figure 3A For Figure 1A and 1B Schematic diagram of the effective visible area of the device for augmented reality display in the illustrated embodiment, Figure 3B For Figure 2A and 2B Schematic diagram of the effective visible area of the device for augmented reality display in the illustrated embodiment. In Figure 3A and 3B In, the grid-like area enclosed by the dashed line represents the size of the effective visible area provided by the device. It can be seen by comparison that Figure 2A and 2B The illustrated embodiments provide a larger effective visible area, which reduces the loss of grating diffraction energy.

[0061] In Figure 1A and 1B as well as Figure 2A and 2BIn the device for augmented reality display shown, the problem of non-uniform efficiency within the field of view is overcome. Specifically, by making the propagation paths of the first light beam and the second light beam symmetric with respect to a reference axis (e.g., Figure 1A and 2A the axis T perpendicular to the X-axis of the coordinate axes in

[0062] In Figure 1A and 1B and Figure 2A and 2B In the device for augmented reality display shown, exemplarily, the first optical functional structures 121, 221 and the third optical functional structures 123, 223 are implemented in the form of two-dimensional gratings, while the second optical functional structures 122, 222 (the first sub-structure 222A, the second sub-structure 222B) are implemented in the form of one-dimensional gratings. Optionally, the one-dimensional grating can be selected from one or more of the following groups: tilted grating, rectangular grating, blazed grating, and volume grating.

[0063] Figures 4A - 4C Shows examples of one-dimensional gratings applicable to Figure 1A and 1B and Figure 2A and 2B In the embodiments shown, among them, Figure 4A Shows the optical diffraction schematic diagram of a rectangular grating, Figure 4B Shows the optical diffraction schematic diagram of a tilted grating, Figure 4C Shows the optical diffraction schematic diagram of a blazed grating.

[0064] In the example, the orientation of the one-dimensional grating depends on the orientation of the two-dimensional grating array used as the first optical functional structure, and the period depends on the periods of the two-dimensional grating arrays of the first optical functional structure and the third optical functional structure. Optionally, the total phase sum of the first to third optical functional structures is zero to satisfy phase matching.

[0065] Refer to Figure 4A , a rectangular grating 421A is formed on the surface of the optical waveguide lens 410. By selecting structural parameters such as grating height, width, and period, light incident on the grating surface at a certain angle forms diffraction through the rectangular grating. The diffracted light includes zero-order diffracted light T0, -1st-order diffracted light T -1 and 1st-order diffracted light T1. In Figure 4A the case shown, the zero-order diffraction efficiency is the highest, the -1st-order diffraction is the second highest, and the 1st-order diffraction efficiency is the lowest. Optionally, Figure 4AThe rectangular grating 421A shown forms -1st order diffracted light, and then completes its propagation within the optical waveguide lens 410.

[0066] Reference Figure 4B , the tilted grating 421B is formed on the surface of the optical waveguide lens 410. By selecting structural parameters such as grating height, width, period, and tilt angle, light incident on the grating surface at a certain angle forms diffraction through the tilted grating. Similarly, the diffracted light includes zero-order diffracted light T0, -1st order diffracted light T -1 and 1st order diffracted light T1. In Figure 4B the case shown, the -1st order diffraction efficiency is the highest, the zero-order diffraction is the second highest, and the 1st order diffraction efficiency is the lowest. Optionally, the -1st order diffracted light can be formed using the Figure 4B tilted grating shown, and then complete its propagation within the optical waveguide lens 410. In addition, by optimizing one or more of the structural parameters such as grating height, width, period, and tilt angle, a wavelength selection function can be achieved, that is, light within a certain wavelength range can have a higher diffraction efficiency, while light within the remaining wavelength ranges has a lower diffraction efficiency.

[0067] Reference Figure 4C , the blazed grating 421C is formed on the surface of the optical waveguide lens 410. By selecting structural parameters such as grating height, period, and blaze angle, light incident on the grating surface at a certain angle forms diffraction through the blazed grating. Similarly, the diffracted light includes zero-order diffracted light T0, -1st order diffracted light T -1 and 1st order diffracted light T1. In Figure 4C the case shown, the -1st order diffraction efficiency is the highest, and the zero-order diffraction and 1st order diffraction efficiencies are the lowest. Optionally, the -1st order diffracted light can be formed using the Figure 4C tilted grating shown, and then complete its propagation within the optical waveguide lens 410. In addition, by optimizing one or more of the structural parameters such as grating height, period, and blaze angle, a wavelength selection function can be achieved.

[0068] Figure 5 Shows examples of two-dimensional gratings that can be applied to Figure 1A and 1B and Figure 2A and 2B the embodiments shown. As Figure 5 shown, the two-dimensional grating is a two-dimensional array. Taking the case of being used for the first optical functional structure as an example, incident light is incident on the first optical functional structure at a certain angle. By designing parameters such as the orientation angle and period of the two-dimensional array, bidirectional angular diffraction can be achieved, and two diffracted light beams are conducted to the second optical functional structure 122, or are respectively conducted to the first sub-structure 222A and the second sub-structure 222B.

[0069] Preferably, the two-dimensional gratings used as the first and third optical functional structures have the same structural parameters (e.g., the duty cycle, period, and orientation of the gratings are the same). In particular, the period of the two-dimensional grating is in the range of 300 - 600 nm.

[0070] In Figure 2A In the device for presenting an image shown, assuming that the grating phase of the first optical functional structure is Φ1, the period is d1, the grating phase of the second optical functional structure is Φ2, the period is d2, the grating phase of the third optical functional structure is Φ3, and the period is d3, in order to ensure that the direction of the outgoing light is the same as the direction of the incident light, the total phase sum of the first to third optical functional structures must be zero to satisfy phase matching, that is According to the phase equation:

[0071]

[0072]

[0073]

[0074] where d is the grating period, λ is the wavelength of the incident light, n is the refractive index of the optical waveguide lens 210, and θ is the diffraction angle of the incident light. From Φ2, we get That is to say, the period of the one-dimensional grating used as the second optical functional structure is set to √2 / 2 times the grating period of the first optical functional structure.

[0075] Figure 6 Shows in Figure 1A and 1B and Figure 2A and 2B The relationship curve between the incident angle of blue light and the transmission efficiency in the device for augmented reality display shown, where the vertical axis represents the transmission efficiency and the horizontal axis represents the incident angle. The grating period used in the device is 420 nm, the height is 250 nm, the duty cycle is 0.3. In the case of an incident wavelength of 450 nm, the incident angles that satisfy total internal reflection propagation of the waveguide lens are from -6.6° to 20°. From Figure 6 It can be seen that by symmetrizing the beam propagation path, the deficiency of unidirectional field of view expansion is effectively compensated, thereby improving the uniformity of the diffraction efficiency of blue light within the exit pupil range.

[0076] Figure 7 Shows in Figure 1A and 1B and Figure 2A and 2BIn the device for augmented reality display shown, the relationship curve between the incident angle of green light and the transmission efficiency, where the vertical axis represents the projection efficiency and the horizontal axis represents the incident angle. The grating period adopted by the device is 420 nm, the height is 250 nm, and the duty cycle is 0.3. At an incident wavelength of 520 nm, the incident angles that satisfy total internal reflection propagation of the waveguide lens are from -12.6° to 13.8°. From Figure 7 It can be seen that by symmetrizing the light beam propagation path, the deficiency of one-way field of view expansion is effectively compensated, thereby improving the uniformity of the diffraction efficiency of green light within the exit pupil.

[0077] Figure 8 Shows in Figure 1A and 1B as well as Figure 2A and 2B In the device for augmented reality display shown, the relationship curve between the incident angle of red light and the transmission efficiency, where the vertical axis represents the projection efficiency and the horizontal axis represents the incident angle. The grating period adopted by the device is 420 nm, the height is 250 nm, and the duty cycle is 0.3. At an incident wavelength of 620 nm, the incident angles that satisfy total internal reflection propagation of the waveguide lens are from -20.1° to 6.5°. From Figure 8 It can be seen that by symmetrizing the light beam propagation path, the deficiency of one-way field of view expansion is effectively compensated, thereby improving the uniformity of the diffraction efficiency of red light within the exit pupil.

[0078] Figure 9 FIG. is a schematic diagram of a system for implementing augmented reality display according to another embodiment of the present invention.

[0079] As Figure 9 shown, the system 1 includes image presentation devices 10A and 10B and an image source 20. The image source 20 is configured to provide light containing image information to the image presentation devices 10A and 10B. In this embodiment, the light from the image source 20 can be light of a single wavelength or can include multiple bands (such as a red light component, a blue light component, and a green light component). The image presentation devices 10A and 10B are configured to present augmented reality images to the user. In this embodiment, exemplarily, the image presentation devices 10A and 10B can be implemented by using the embodiments described above with the aid of Figure 1A , Figure 1B , Figure 2A , 2B , Figures 4A - 4C and Figure 5 to describe.

[0080] Referring to Figure 9 , the system 1 for implementing augmented reality display further includes a connecting component 10C that connects the image presentation devices 10A and 10B together.

[0081] The principles and preferred embodiments of the present invention have been described above. However, the present invention should not be construed as limited to the specific embodiments discussed. The above preferred embodiments should be considered illustrative rather than restrictive, and it should be understood that those skilled in the art can make changes in these embodiments without departing from the scope of the present invention as defined by the following claims.

Claims

1. An apparatus for presenting an image, characterized in that, Comprising: An optical waveguide lens; And A first optical functional structure, a second optical functional structure, and a third optical functional structure disposed on the surface of the optical waveguide lens, wherein the second optical functional structure is located between the first optical functional structure and the third optical functional structure, wherein light incident on the first optical functional structure forms a first light beam and a second light beam under the action of the first optical functional structure. The first light beam propagates to the second optical functional structure by total internal reflection within the optical waveguide lens, and the second light beam propagates to the second optical functional structure by total internal reflection within the optical waveguide lens. Under the action of the second optical functional structure, the first light beam and the second light beam propagate to the third optical functional structure by total internal reflection within the optical waveguide lens and are emitted after being combined by the third optical functional structure, wherein the propagation directions of the first light beam and the second light beam within the optical waveguide lens are different and symmetric with respect to a reference axis, and the reference axis is perpendicular to the horizontal axis of the device, wherein the first optical functional structure, the second optical functional structure, and the third optical functional structure are symmetrically disposed on the surface of the optical waveguide lens with respect to the reference axis, wherein the first optical functional structure and the third optical functional structure are two-dimensional gratings, the second optical functional structure is a single one-dimensional grating and its shape is rectangular, and the one-dimensional grating is configured to cause the first light beam and the second light beam to enter the third optical functional structure at symmetric incident angles with respect to the reference axis.

2. The device according to claim 1, wherein, The first optical functional structure, the second optical functional structure, and the third optical functional structure are located on the same surface of the optical waveguide lens.

3. The device according to claim 1, wherein, The one-dimensional grating is one of the following: a tilted grating, a rectangular grating, a blazed grating, and a volume grating.

4. The device according to claim 1, wherein, The total phase sum of the first optical functional structure, the second optical functional structure, and the third optical functional structure is zero to satisfy phase matching.

5. The device according to claim 1, wherein, The two-dimensional gratings used as the first optical functional structure and the third optical functional structure have the same structural parameters.

6. The device according to claim 5, wherein, The period of the two-dimensional grating is in the range of 300 - 600 nm.

7. The device according to claim 1, wherein, The period of the one-dimensional grating used as the second optical functional structure is set to be times that of the grating period of the first optical functional structure.

8. A system for implementing augmented reality display, characterized in that, Comprising: An image source configured to provide light containing image information; And An image presenting device, comprising: An optical waveguide lens; and A first optical functional structure, a second optical functional structure, and a third optical functional structure disposed on the surface of the optical waveguide lens, wherein the second optical functional structure is located between the first optical functional structure and the third optical functional structure, wherein incident light from the image source forms a first light beam and a second light beam under the action of the first optical functional structure. The first light beam propagates to the second optical functional structure by total internal reflection within the optical waveguide lens, and the second light beam propagates to the second optical functional structure by total internal reflection within the optical waveguide lens. Under the action of the second optical functional structure, the first light beam and the second light beam propagate to the third optical functional structure by total internal reflection within the optical waveguide lens and are emitted after being combined by the third optical functional structure, Wherein, the propagation directions of the first light beam and the second light beam in the optical waveguide lens are different and symmetric with respect to a reference axis, and the reference axis is perpendicular to the horizontal axis of the device. Wherein, the first optical functional structure, the second optical functional structure and the third optical functional structure are symmetrically arranged on the surface of the optical waveguide lens with respect to the reference axis. Wherein, the first optical functional structure and the third optical functional structure are two-dimensional gratings, the second optical functional structure is a single one-dimensional grating and its shape is rectangular, and the one-dimensional grating is configured to make the first light beam and the second light beam enter the third optical functional structure at incident angles symmetric with respect to the reference axis.

9. The system according to claim 8, wherein, The first optical functional structure, the second optical functional structure and the third optical functional structure are located on the same surface of the optical waveguide lens.

10. The system according to claim 8, wherein, The one-dimensional grating is one of the following: a tilted grating, a rectangular grating, a blazed grating and a volume grating.

11. The system according to claim 8, wherein, The total phase sum of the first optical functional structure, the second optical functional structure and the third optical functional structure is zero to satisfy phase matching.

12. The system according to claim 8, wherein, The two-dimensional gratings used as the first optical functional structure and the third optical functional structure have the same structural parameters.

13. The system according to claim 12, wherein, The period of the two-dimensional grating is in the range of 300-600 nm.

14. The system according to claim 8, wherein, The period of the one-dimensional grating used as the second optical functional structure is set to be times that of the grating period of the first optical functional structure.

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