A curved holographic waveguide display device and display method for a large eye box

Abstract

A curved holographic waveguide display device and method with a large pupil box are disclosed. The device includes a microdisplay, a first relay optical element group, a planar waveguide module, and a curved holographic waveguide module. This invention utilizes the planar waveguide module to transform a small exit pupil projection module composed of a microdisplay and the first relay optical element group into a large exit pupil projection module without sacrificing the field of view. This provides a wide beam covering the entire field of view image information for the curved holographic waveguide module, thereby achieving a virtual-real fusion effect between the optical image and the real world environment within the wide pupil box. This invention also proposes adding a second relay optical element group or relay optical element to the curved holographic waveguide display device to better achieve the conjugate matching between the planar waveguide module and the curved holographic waveguide module. This invention simplifies the structure of the large exit pupil projection module, reduces the module volume, and provides a key design scheme and implementation method for the lightweight miniaturization of curved waveguide head-mounted displays.

Description

Technical Field

[0001] This invention relates to the field of near-eye displays, and more specifically, to a curved holographic waveguide display device and display method with a large pupil box. Background Technology

[0002] Augmented Reality (AR) is a display technology that interweaves the real physical world with rich digital information. Waveguide-type near-eye displays, as key devices in AR applications and usage, possess unique advantages in optical perspective and form factor, greatly promoting a deep sense of immersion and highly perceptive human-computer interaction process. They can meet the requirements of the human visual system for superior performance and are conducive to the development of lightweight head-mounted displays. Unlike planar waveguides, curved waveguide beam combiners exhibit stronger spatial integration capabilities, presenting a more aesthetically pleasing design, and are of great significance in terms of form adaptation and aesthetic appeal.

[0003] In exit pupil formation systems with a certain optical extension, there is a mutually constraining relationship between the pupil box size and the field of view; that is, the product of the image source display panel size and the numerical aperture generated by the optical relay system remains constant. The advantage of waveguide combiners lies in their ability to overcome the limitations of optical extension by utilizing exit pupil expansion, thereby effectively expanding the pupil box area without sacrificing the field of view. The application of exit pupil expansion technology enables waveguide-type near-eye displays to integrate small-sized microdisplays, achieving compact and lightweight large-pupil-box waveguide combiners.

[0004] An ideal pupil box can be achieved through one-dimensional or two-dimensional exit pupil expansion techniques. In one-dimensional exit pupil expansion, a narrow, elongated coupling optical element is placed along the propagation direction of the internal reflection optical path to cyclically copy the image information received at the input end, thereby extending the pupil box region along a one-dimensional direction. In contrast, two-dimensional exit pupil expansion relies on two consecutive one-dimensional exit pupil expansions with different directions. This technique generally uses a redirection or deflection grating placed in the middle to copy, expand, and redirect the input pupil information, and then performs a secondary expansion through the coupling optical element to achieve the two-dimensional pupil expansion effect. However, these pupil expansion techniques are currently mainly used in planar waveguides. For curved waveguides, copying and expanding the input pupil information becomes challenging due to image distortion caused by curvature.

[0005] Patent document CN117031617A discloses a curved holographic waveguide assembly with two-dimensional pupil expansion function. This assembly consists of an image source, a curved waveguide, an input holographic grating, a bend holographic grating, and an output holographic grating. Light emitted from the image source first interacts with the input holographic grating, then undergoes total internal reflection within the curved waveguide and propagates. After interacting with the bend holographic grating and the output holographic grating respectively, the light finally enters the observer's field of vision. Patent document CN110806645A discloses a grating waveguide system for augmented reality. This system includes a display light source, a waveguide element disposed opposite to the display light source, and a first input grating and a first output grating disposed on the waveguide element. Light emitted from the display light source undergoes total internal reflection within the waveguide element after passing through the waveguide element and the first input grating, and then enters the observer's field of vision through the first output grating and the waveguide element. However, the above solutions either involve additional design for the two-dimensional pupil expansion function of the fold holographic grating, making the fabrication process reproducible, or require the integration of a large exit pupil projection module to adapt to the exit pupil expansion requirements of the grating waveguide system, which is not conducive to the miniaturization of the device. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a curved holographic waveguide display device and display method with a large pupil box. By integrating a one-dimensional or two-dimensional pupil-expanding planar waveguide and a curved waveguide for modulating a large numerical aperture beam, the effective expansion of the pupil box is achieved, while maintaining a compact shape and low manufacturing cost. This improves the coupling efficiency and propagation quality of the beam, enabling the device to achieve efficient and distortion-free image transmission under different spatial layouts.

[0007] The technical solution of the present invention is as follows:

[0008] On one hand, the present invention provides a curved holographic waveguide display device with a large pupil box, characterized in that it includes:

[0009] Microdisplays are used to load monochrome or color images across the entire field of view;

[0010] The first relay optical element group is disposed in front of the microdisplay and is used to collimate the conical beam emitted by the microdisplay to form parallel beams of narrow beams at different angles, and to ensure that the propagation direction of different wavelengths of light generated by the same pixel is consistent, thus forming a unified field of view.

[0011] The planar waveguide module, as a planar waveguide module, is used to receive the narrow beam parallel light and achieve one-dimensional or two-dimensional exit pupil expansion through total internal reflection, redirection and coupling, forming a wide beam parallel light with a large exit pupil. Its exit pupil coincides with the entrance pupil of the curved holographic waveguide module and the size matches, and the field of view corresponds to each other.

[0012] A curved holographic waveguide module is used to receive the wide beam of parallel light, which is propagated and coupled out through total internal reflection to form a virtual image that can be observed in a large exit pupil region.

[0013] Furthermore, it also includes a second relay optical element group disposed between the planar waveguide module and the curved holographic waveguide module to ensure the conjugate relationship between the exit pupil of the planar waveguide module and the entrance pupil of the curved holographic waveguide module, that is, the exit pupil of the planar waveguide module is imaged onto the entrance pupil of the curved holographic waveguide module.

[0014] Preferably, the second relay optical element group includes a first relay lens and a second relay lens, and the optical axes of the first relay lens and the second relay lens coincide, the rear focal point of the first relay lens coincides with the front focal point of the second relay lens, and the optical axes of the second relay optical system coincide with the optical axes of the first output optical element and the second input optical element.

[0015] Furthermore, it also includes a relay optical element attached to the inner or outer surface of the curved holographic waveguide module to ensure that the exit pupil of the planar waveguide module and the entrance pupil of the curved holographic waveguide module are conjugate.

[0016] Preferably, the planar waveguide module is arranged radially and interleaved with the curved holographic waveguide module in the front and back, and staggered tangentially.

[0017] The planar waveguide module includes a planar waveguide, a first coupling optical element, a redirection optical element, and a first coupling out optical element; a narrow beam of parallel light from the first relay optical element group is coupled into the first coupling optical element, propagates through total internal reflection within the planar waveguide, expands the exit pupil through the redirection optical element, and is then diffracted out by the first coupling out optical element;

[0018] The curved holographic waveguide module includes a curved waveguide, a second coupled optical element, and a second coupled optical element. A wide beam of parallel light from the planar waveguide module is coupled into the second coupled optical element, propagates through total internal reflection within the curved waveguide, and is diffracted out through the second coupled optical element to form a distortion-free full-field image.

[0019] Preferably, the parallel beams of each wide field of view in the modulated light field of the first coupled optical element converge toward the parallel beam of the central field of view to form the exit pupil, which together constitutes the entrance pupil of the curved holographic waveguide module.

[0020] Preferably, the second coupling optical element and the second coupling optical element are arranged on the inner or outer surface of the curved waveguide while ensuring a certain relative positional relationship; the establishment position of the construction point of the second coupling optical element and the second coupling optical element should be accurately calculated based on the surface shape of the curved waveguide to realize image transmission without distortion accumulation when propagating tangentially along the curved waveguide.

[0021] Preferably, the second coupled-in optical element and the second coupled-out optical element can be composed of any of the following forms: a single layer of three-color composite diffraction optical element; a single layer of two-color composite diffraction optical element and a single layer of monochromatic diffraction optical element superimposed with a high distribution; three layers of different monochromatic diffraction optical elements superimposed with a high distribution; and a reasonable selection is made according to diffraction efficiency and diffraction uniformity.

[0022] On the other hand, the present invention also provides a display method for a curved holographic waveguide display device using the above-mentioned large pupil box, characterized in that it includes:

[0023] Step 1: Load a monochrome or color image across the entire field of view using a microdisplay;

[0024] Step 2: Collimate the beams from each field of view of the microdisplay using the first relay optical element group to form a narrow beam of parallel light;

[0025] Step 3: Expand the exit pupil in one or two dimensions using a planar waveguide module to couple out a wide beam of parallel light;

[0026] Step 4: Use a curved holographic waveguide module to guide the tangential propagation of the wavefront and couple out a distortion-free full-field image. The resulting virtual image can be perfectly integrated into the human eye with the real environment over a wide area.

[0027] Preferably, between steps 3 and 4, the method further includes: selecting a relay optical element or a second relay optical element group according to the position of the exit pupil of the planar waveguide module, and modulating the wide beam wavefront to meet the modulation conditions and entrance pupil requirements of the curved holographic waveguide module.

[0028] Preferably, the first relay optical element group is a lens group consisting of a single lens, a cemented doublet lens, or multiple lenses.

[0029] Preferably, the second relay optical element group consists of two relay lenses; the relay lens is a single lens, a cemented doublet lens, or a lens group composed of multiple lenses.

[0030] The curved holographic waveguide module is used as part or a portion of the freeform curved screen of a head-mounted display.

[0031] Compared with the prior art, the present invention has the following obvious and prominent substantive features and significant advantages:

[0032] 1. The device of this invention uses a planar waveguide module to transform a small exit pupil projection module, consisting of a microdisplay and a first relay optical element group, into a large exit pupil projection module without sacrificing the field of view, providing a wide beam covering the entire field of view image information for the curved holographic waveguide module. This method simplifies the structure of the large exit pupil projection module, reduces the module size, and provides a key component for the lightweight miniaturization of head-mounted displays.

[0033] 2. This invention uses a curved holographic waveguide module as a curved beam combiner, which serves as the whole or part of the freeform curved screen of a head-mounted display. It directly receives full-field-of-view image information, or indirectly receives full-field-of-view image information through relay optical elements or a second relay optical element group, providing users with a large pupil box area that condenses full-field-of-view information and meeting users' needs for the fusion of virtual and real information under the curved screen.

[0034] 3. The curved holographic waveguide module in this invention enables distortion-free image transmission when light propagates tangentially along the curved waveguide. The specially designed volume holographic grating ensures that the spot size on the inner and outer surfaces of the curved waveguide remains consistent in every field of view, thereby guaranteeing distortion-free coupling of image information from total internal reflection within the waveguide medium. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a curved holographic waveguide display device with a large pupil box provided in Embodiment 1 of the present invention.

[0036] Figure 2 This is a schematic diagram of the holographic optical elements arranged tangentially in the planar waveguide module provided in Embodiment 1 of the present invention.

[0037] Figure 3 This is a schematic diagram of the "L-shaped" arrangement of holographic optical elements in the planar waveguide module provided in Embodiment 1 of the present invention.

[0038] Figure 4 This is a schematic diagram of the arrangement of geometric optical elements in the planar waveguide module provided in Embodiment 1 of the present invention.

[0039] Figure 5 This is a schematic diagram of the arrangement of holographic optical elements in the curved holographic waveguide module provided in Embodiment 1 of the present invention.

[0040] Figure 6 This is a schematic diagram of the construction light relationship of the second coupled optical element in the cylindrical surface curved holographic waveguide module provided in Embodiment 1 of the present invention.

[0041] Figure 7 This is a schematic diagram of the construction light relationship of the second coupled optical element in the cylindrical surface curved holographic waveguide module provided in Embodiment 1 of the present invention.

[0042] Figure 8 This is a schematic diagram of a curved holographic waveguide display device for a large-eye pupil box, provided in Embodiment 2 of the present invention, in which the exit pupil-oriented curved holographic waveguide in the space on the user side of the first coupled optical element is guided by the second relay optical element group to the pupil for matching.

[0043] Figure 9 This is a schematic diagram of a curved holographic waveguide display device for a large pupil box, provided in Embodiment 3 of the present invention, in which the exit pupil of the first coupled optical element on the side of the curved holographic waveguide is matched to the exit pupil of the curved holographic waveguide by the second relay optical element group.

[0044] Figure 10 This is a schematic diagram of a curved holographic waveguide display device for a large-eye pupil box, provided in Embodiment 4 of the present invention, in which a relay optical element guides the exit pupil-oriented curved holographic wave from the first coupled optical element in the space on the user side to the pupil for pupil matching.

[0045] Figure 11 This is a schematic diagram of a curved holographic waveguide display device for a large-eye pupil box, provided in Embodiment 5 of the present invention, in which the exit pupil of the first coupled optical element on the side of the curved holographic waveguide is matched to the exit pupil of the curved holographic waveguide by a relay optical element. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The following embodiments are specifically designed for curved holographic waveguide display devices with large pupil boxes for augmented reality (AR) and virtual reality (VR) applications. This device aims to improve the field of view, exit pupil size, and user experience of head-mounted displays and is suitable for portable display devices such as smart glasses.

[0048] Example 1

[0049] An embodiment of the curved holographic waveguide display device with a large pupil box of the present invention, such as... Figure 1 As shown, the curved holographic waveguide display device of the large-eye pupil box includes a microdisplay 100, a first relay optical element group 200, a planar waveguide module 300, and a curved holographic waveguide module 400.

[0050] The microdisplay 100 is a miniaturized image source capable of providing monochrome or color images with a certain resolution and contrast for a curved holographic waveguide display device with a large pupil box, covering the entire field of view. The microdisplay 100 is a monochrome or color image source, and its single or multi-channel emission center wavelength matches the modulation wavelength of the planar waveguide module 300 and the curved holographic waveguide module 400. This microdisplay can be a light-modulated liquid crystal (LCD) microdisplay, a liquid crystal on silicon (LCoS) microdisplay, a digital light processing (DLP) microdisplay, or a self-emissive organic light-emitting diode (OLED) microdisplay, a micro-LED (μLED) microdisplay, or a laser beam scanning (LBS) microdisplay with a narrow band spectrum.

[0051] The first relay optical element group 200 is a projection system with collimation function and good imaging performance. The microdisplay 100 is generally located on the front focal plane of the first relay optical element group 200. The first relay optical element group 200 collimates the conical beam emitted by the pixels in the image source plane of the microdisplay 100 to form a narrow beam with a specific propagation direction angle under the corresponding field of view. Light rays of different wavelengths generated by the same pixel have the same propagation direction after collimation, that is, a unified field of view is formed. The pixels from the center to the periphery of the microdisplay 100 participate in the formation of the central and peripheral field of view, forming the exit pupil and constituting the entrance pupil of the planar waveguide module 300. The first relay optical element group 200 is a lens group composed of a single lens, a cemented doublet lens, or multiple lenses.

[0052] The planar waveguide module 300 is a planar waveguide module that performs lossless total internal reflection propagation of coupled multi-angle parallel beams, while simultaneously expanding the exit pupil in one or two dimensions and coupling out multi-angle beams to form a large exit pupil. The planar waveguide module 300 and the curved holographic waveguide module 400 are arranged radially front-to-back and staggered horizontally in the tangential direction. The exit pupil of the planar waveguide module 300 coincides with the entrance pupil of the curved holographic waveguide module 400, and their sizes are matched. The image-side field of view of the planar waveguide module 300 must match the object-side field of view of the curved holographic waveguide module 400. Both the planar waveguide module 300 and the curved holographic waveguide module 400 have optical elements arranged in a specific order, possess a specific propagation mode, and have the ability to conduct light and fold optical paths.

[0053] The planar waveguide module 300 includes a planar waveguide 310, a first coupling optical element 320, a redirection optical element 330, and a first coupling optical element 340. The first coupling optical element 320, the redirection optical element 330, and the first coupling optical element 340 are arranged on the inner or outer surface of the planar waveguide 310 while maintaining a certain relative positional relationship. The planar waveguide 310 is an optical device capable of guiding total internal reflection propagation of light. Both surfaces have infinite curvature, a rectangular cross-section, and a thickness comparable to that of a typical eyeglass lens. The planar waveguide 310 is made of inorganic materials such as glass or organic optical materials such as polymers, with a refractive index between 1.3 and 2.2, and is a propagation medium with uniform thickness and a constant refractive index. The planar waveguide module 300 couples a narrow beam wavefront into the planar waveguide 310 via a first coupling optical element 320, allowing the modulated light path to propagate through total internal reflection within the upper and lower surfaces of the planar waveguide 310. A specific pupil expansion method is implemented via a redirection optical element 330 to achieve one-dimensional or two-dimensional exit pupil expansion. Finally, a wide beam wavefront is coupled out via a first output optical element 340 to form a large exit pupil, which is simultaneously projected onto the curved holographic waveguide module 400. The planar waveguide module 300 transforms the small exit pupil projection module composed of the microdisplay 100 and the first relay optical element group 200 into a large exit pupil projection module without sacrificing the field of view, providing the curved holographic waveguide module 400 with a wide beam covering the entire field of view image information. This method simplifies the structure of the large exit pupil projection module, reduces the module size, and provides a key component for the lightweight miniaturization of head-mounted displays.

[0054] The curved holographic waveguide module 400 is a curved waveguide optical combiner, composed of a curved waveguide 410, a second coupling optical element 420, and a second coupling optical element 430. The second coupling optical element 420 and the second coupling optical element 430 are sequentially arranged tangentially along the inner or outer surface of the curved waveguide 410. The eye is located near the exit pupil of the curved holographic waveguide module 400. The curved waveguide 410 is an optical device capable of guiding total internal reflection propagation of light. Its two surfaces have the same center of curvature but different radii of curvature, and the thickness is uniform at different locations. The curved waveguide 410 is made of inorganic materials such as glass or organic optical materials such as polymers, with a refractive index between 1.3 and 2.2, making it a propagation medium with uniform thickness and a constant refractive index. The curved waveguide 410 typically has a surface dimension similar to that of a helmet visor, with a radius of curvature between approximately 150 and 250 mm and a thickness between 2 and 6 mm. The second coupling optical element 420 and the second coupling optical element 430 are holographic optical elements. Commonly used holographic recording media include silver halide emulsion, dichromate gelatin, photoresist, photopolymer, and photothermal conductive plastics. The second coupling optical element 420 and the second coupling optical element 430 should be flexibly selected and combined using various reflective or transmissive diffractive optical elements according to design requirements. These diffractive optical elements can be holographic optical elements, volume holographic optical elements, surface relief gratings, or polarizing gratings. They can also be replaced with various geometric optical elements.

[0055] For the planar waveguide module 300, the parallel beams of each wide-field-of-view beam in the modulated optical field of the first coupled optical element 340 converge towards the parallel beam of the central field of view, forming the exit pupil, which together constitutes the entrance pupil of the curved holographic waveguide module 400. The second coupled optical element 420 is located on the outer or inner surface of one end of the curved waveguide. The entrance pupil position of the second coupled optical element 420 coincides with the exit pupil of the first coupled optical element 340 and their sizes match. The object-side field of view of the second coupled optical element 420 must match the image-side field of view of the first coupled optical element 340; while obtaining the maximum optical energy, the modulation wavelength and modulation angle of the second coupled optical element 420 are matched with the wavelength information of the beam and the propagation angle of the central field of view to obtain the maximum diffraction efficiency. During propagation, the light beams continuously expand and converge on the inner and outer surfaces of the curved waveguide, ensuring that the spot sizes of the light rays in each field of view remain consistent on the inner and outer surfaces. This ensures that the image information from total internal reflection within the waveguide medium can propagate without distortion. Ultimately, a large pupil box region containing information from the entire field of view is formed on the inner side of the curved waveguide. Through the diffraction of the second coupling optical element 430 on the outer or inner surface of the other end of the curved waveguide, the human eye can receive a complete virtual image within a relatively wide exit pupil range. At the same time, real information can be observed through the high-transmittance curved waveguide 410, satisfying the user's need for the fusion of virtual and real information.

[0056] One embodiment of the planar waveguide module 300 is as follows: Figure 2As shown. The planar waveguide module 300 includes a planar waveguide 310, a first coupled-in optical element 320, a redirected optical element 330, and a first coupled-out optical element 340. The first coupled-in optical element 320, the redirected optical element 330, and the first coupled-out optical element 340 are holographic optical elements. Commonly used holographic recording media include silver halide emulsion, dichromate gelatin, photoresist, photopolymer, and photothermal conductive plastic. The first coupled-in optical element 320, the redirected optical element 330, and the first coupled-out optical element 340 should be flexibly selected and combined with various reflective or transmissive diffractive optical elements according to design requirements. The diffractive optical elements can be holographic optical elements, volume holographic optical elements, surface relief gratings, or polarizing body gratings. The first coupled-in optical element 320, the redirected optical element 330, and the first coupled-out optical element 340 are sequentially attached tangentially to the outer or inner surface of the planar waveguide 310. The first coupling optical element 320 is located on the outer or inner surface of one end of the curved waveguide. The entrance pupil of the first coupling optical element 320 coincides with the exit pupil of the first relay optical element group 200 and their sizes are matched. The object-side field of view of the first coupled optical element 320 must match the image-side field of view of the first relay optical element group 200. While obtaining the maximum optical energy, the modulation wavelength and modulation angle of the first coupled optical element 320 must match the wavelength information of the beam and the propagation angle of the central field of view to obtain the maximum diffraction efficiency. The reorienting optical element 330 has the dual functions of replication and deflection. It can replicate the original total internal reflection beam into multiple orders through diffraction and cause part of the beam to deflect relative to the original propagation direction. In this way, the reoriented replicated beams converge to form a beam cluster, realizing one-dimensional pupil expansion in the positive and negative axial directions. The coupled optical element 340 is located on the outer or inner surface of the other end of the waveguide. Its axial dimension is equivalent to the axial width of the one-dimensional pupil expansion, and its radial length should meet the pupil expansion design requirements of the exit pupil plane of the device. This enables the overall coupling out of the two-dimensional pupil expansion beam clusters of different wavelengths at various field of view angles. At this time, the conjugate image should be formed on the opposite side of the image input end.

[0057] Another embodiment of the planar waveguide module 300 is, for example Figure 3As shown. The planar waveguide module 300 includes a planar waveguide 311, a first coupling optical element 321, a redirection optical element 331, and a first coupling optical element 341. The first coupling optical element 321, the redirection optical element 331, and the first coupling optical element 341 are holographic optical elements. Commonly used holographic recording media include silver halide emulsion, dichromate gelatin, photoresist, photopolymer, and photothermal conductive plastic. The first coupling optical element 321, the redirection optical element 331, and the first coupling optical element 341 should be flexibly selected and combined with various reflective or transmissive diffractive optical elements according to design requirements. The diffractive optical elements can be holographic optical elements, volume holographic optical elements, surface relief gratings, or polarizing body gratings.

[0058] The first coupling optical element 321, the redirection optical element 331, and the first coupling optical element 341 are sequentially attached to the outer or inner surface of the planar waveguide 311 in an "L" shape. The first coupling optical element 321 is located on the outer or inner surface of one end of the curved waveguide, and the entrance pupil of the first coupling optical element 321 coincides with and matches the size of the exit pupil of the first relay optical element group 200. The object-side field of view of the first coupled optical element 321 must match the image-side field of view of the first relay optical element group 200. While obtaining the maximum optical energy, the modulation wavelength and modulation angle of the first coupled optical element 321 must match the wavelength information of the beam and the propagation angle of the central field of view to obtain the maximum diffraction efficiency. The redirecting optical element 331 has the dual functions of replication and deflection. It can replicate the original total internal reflection beam into multiple orders through diffraction and cause part of the beam to deflect relative to the original propagation direction. In this way, the reoriented replicated beams converge to form a beam cluster, realizing one-dimensional pupil expansion in the axial direction. The coupled optical element 341 is located on the outer or inner surface of the other end of the waveguide. Its axial dimension is equivalent to the axial width of the one-dimensional pupil expansion, and its radial length should meet the pupil expansion design requirements of the exit pupil plane of the device. This enables the overall coupling out of the two-dimensional pupil expansion beam clusters of different wavelengths at various field of view angles. At this time, the conjugate image should be formed on the opposite side of the image input end.

[0059] Another embodiment of the planar waveguide module 300 is, for example Figure 4 As shown. The planar waveguide module 300 includes a planar waveguide 312, a first coupling optical element 322, a redirection optical element 332, and a first coupling optical element 342. The first coupling optical element 322, the redirection optical element 332, and the first coupling optical element 342 are respectively a reflecting plane or prism, a cascaded semi-transparent semi-reflective mirror or microprism array, and a cascaded semi-reflective mirror or microprism array.

[0060] The first coupling optical element 322, the redirection optical element 332, and the first coupling optical element 342 are L-shaped and located on the surface of the planar waveguide 312 or embedded in the planar waveguide 312. The first coupling optical element 322 is located on the surface of one end of the planar waveguide 312 or embedded therein, and the entrance pupil position of the first coupling optical element 322 coincides with and matches the size of the exit pupil of the first relay optical element group 200. The object-side field of view of the first coupling optical element 322 must match the image-side field of view of the first relay optical element group 200. At the same time, the design angle of the reflecting plane satisfies the total internal reflection condition of light in the waveguide substrate within the entire field of view to obtain sufficient coupling efficiency. The redirecting optical element 332 has the dual functions of replication and deflection. It can transmit part of the light to continue the original axial propagation optical path, and through continuous reflection, it can cause another part of the light to be tangentially deflected at a certain angle relative to the original propagation direction. In this way, the reoriented replicated beams converge to form a beam cluster, realizing one-dimensional pupil expansion in the axial direction. The coupling optical element 342 is located at the other end of the waveguide. Its axial dimension is equivalent to the axial width of the one-dimensional pupil expansion, and its radial length should meet the pupil expansion design requirements of the device's exit pupil plane. This enables the overall coupling out of two-dimensional pupil expansion beam clusters of different wavelengths at various field of view angles. At this time, the conjugate image should be formed on the opposite side of the image input end.

[0061] In the curved holographic waveguide display device of the large-eye pupil box, the location of the construction points of the curved holographic optical elements should be precisely calculated based on the surface shape of the curved waveguide 410. This aims to achieve distortion-free cumulative transmission of the image when light propagates tangentially along the curved waveguide 410. For curved waveguides with cylindrical surfaces, the specially designed volume holographic grating causes the modulation wavefront to converge towards the center of curvature first. Due to the different focal lengths of the inner and outer curved surfaces of the waveguide, this results in the beam diverging, converging, diverging again, and converging again sequentially… The key is to ensure that the spot size of the inner and outer surfaces remains consistent in every field of view, thereby guaranteeing distortion-free coupling of the image information from total internal reflection within the waveguide medium.

[0062] like Figure 5 The diagram illustrates the relative spatial relationship between the second coupled-in optical element 420 and the second coupled-out optical element 430 on the surface of a curved holographic waveguide module 400 with a cylindrical surface profile. The second coupled-in optical element 420 and the second coupled-out optical element 430 can be composed of any of the following forms: a single layer of three-color composite diffraction optical elements; a single layer of two-color composite diffraction optical elements and a single layer of monochromatic diffraction optical elements stacked at a high degree of distribution; or three layers of different monochromatic diffraction optical elements stacked at a high degree of distribution. In practical applications, a reasonable selection should be made based on diffraction efficiency and diffraction uniformity.

[0063] like Figure 6The diagram illustrates the holographic structure function of the second coupled optical element 420 within a curved holographic waveguide module 400 with a cylindrical surface. The second coupled optical element 420 is attached to the inner or outer surface of one end of the curved waveguide 410. It is typically fabricated using methods such as holographic exposure or holographic printing. The hologram recorded by the second coupled optical element 420 is formed by the interference of planar reference light emitted from the outer side of the curved surface and propagating along the normal direction within the holographic optical element, and divergent cylindrical signal light emitted from the inner side of the curved surface and propagating at a certain angle to the normal direction of the holographic optical element, under conditions of coherence.

[0064] The deflection angle of the off-axis signal light path must satisfy the condition for total internal reflection between the inner and outer surfaces of the curved waveguide. Simultaneously, by precisely controlling the diffraction angle distribution of the light under different fields of view, the corresponding modulation wavefront achieves high and uniform diffraction efficiency. Therefore, the angle between the two constructing beams should be within the range of 50° to 65°. Furthermore, the location of the constructing point on the off-axis light path should ensure that the total internal reflection process does not cause image distortion.

[0065] like Figure 7 The diagram illustrates the holographic structure function contained in the second coupled optical element 430 of a curved holographic waveguide module 400 with a cylindrical surface. The second coupled optical element 430 in the curved holographic waveguide module 400 is attached to the inner or outer surface of the other end of the curved waveguide 410. It is typically fabricated using holographic exposure and holographic printing methods. The hologram recorded by the second coupled optical element 430 is formed by the interference of planar signal light emitted from the outer side of the curved surface and propagating along the normal direction inside the holographic optical element, and divergent cylindrical reference light emitted from the inner side of the curved surface and propagating at a certain angle to the normal of the holographic optical element, under coherence conditions. In other words, when constructing the hologram of the second coupled optical element 430, the spatial positions of the reference light and signal light in the construction light participating in the establishment of the coupled holographic structure function are axially symmetric relative to the normal of the holographic optical element. The reference light and signal light before axial symmetry are then regarded as the current signal light and reference light, and a new coupled holographic structure function is formed through interference exposure. Accordingly, the angle between the two constructed beams should be within the range of 50° to 65°.

[0066] This invention realizes a curved holographic waveguide display method for a large pupil box. The microdisplay 100 is used to load monochrome or color images in the full field of view. The first relay optical element group 200 collimates the conical beams from each pixel in the image source plane of the microdisplay 100, forming narrow beam parallel light at different angles. The entrance pupil position of the planar waveguide module 300 coincides with and matches the exit pupil of the first relay optical element group 200; the object-side field of view of the planar waveguide module 300 must match the image-side field of view of the first relay optical element group 200. The planar waveguide module 300 serves as a planar pupil expanding device, where the narrow beam wavefront is coupled by the first coupling optical element 320 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the planar waveguide 310, and the exit pupil is expanded by a specific method through the redirection optical element 330, before being diffracted by the first output optical element 340. The entrance pupil of the curved holographic waveguide module 400 coincides with and matches the exit pupil of the planar waveguide module 300; the field of view of the curved holographic waveguide module 400 must match the image-side field of view of the planar waveguide module 300. The curved holographic waveguide module 400 is essentially a curved waveguide combiner, where a wide-beam parallel light is coupled by a second coupling optical element 420 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the curved holographic waveguide 410, ensuring that the spot size on the inner and outer surfaces remains consistent across each field of view, achieving tangential distortion-free propagation. Finally, it is diffracted by a second output element 430 on the other end surface, forming a virtual image that can be observed by the human eye within a relatively wide exit pupil area. This method enables curved holographic waveguide displays with large pupil boxes that can be used as part or integral components of freeform curved screens for head-mounted displays, providing users of portable display devices such as smart glasses with a stable and continuous augmented reality visual experience in dynamic scenes. This display method eliminates the need for large display panels and space-consuming relay optics systems. Instead, it ensures effective expansion of the pupil box by integrating one-dimensional or two-dimensional pupil-expanding planar waveguide devices based solely on curved waveguides capable of modulating large numerical aperture beams. This design integrates smaller microdisplays and relay optics, achieving a compact form factor and significantly reducing the manufacturing cost of head-mounted displays.

[0067] Example 2

[0068] An embodiment of the curved holographic waveguide display device with a large pupil box of the present invention, such as... Figure 8 As shown, the curved holographic waveguide display device of the large-eye pupil box includes a microdisplay 100, a first relay optical element group 200, a flat waveguide module 300, a curved holographic waveguide module 400, and a second relay optical element group 500.

[0069] The second relay optical system 500 is a single lens, a cemented doublet lens, or a lens group composed of multiple lenses, or includes diffractive optical elements with the same optical functions as lenses, which together serve as a projection system to ensure that the exit pupil of the planar waveguide module 300 and the entrance pupil of the curved holographic waveguide module 400 are in a conjugate relationship. The diffractive optical element can be a holographic optical element, a volume holographic optical element, a surface relief grating, or a polarizing volume grating.

[0070] like Figure 8 As shown, the second relay optical system 500 consists of a first relay lens 510 and a second relay lens 520. The basic structure of the second relay optical system 500 is a 4f optical system. The optical axes of the first relay lens 510 and the second relay lens 520 coincide, the rear focal point of the first relay lens 510 coincides with the front focal point of the second relay lens 520, and the optical axes of the second relay optical system 500 coincide with those of the first output optical element 340 and the second input optical element 420. Based on the system conjugate relationship, the second relay optical system 500 images the exit pupil of the planar waveguide module 300 onto the entrance pupil of the curved holographic waveguide module 400. The focal lengths of the first relay lens 510 and the second relay lens 520 are determined by the dimensional relationship between the exit pupil of the planar waveguide module 300 and the entrance pupil of the curved holographic waveguide module 400. The first relay lens 510 can be a single lens, a cemented doublet lens, or a lens group composed of multiple lenses. The second relay lens 520 can be a single lens, a cemented doublet lens, or a lens group composed of multiple lenses.

[0071] This embodiment realizes a curved holographic waveguide display device with a large pupil box. The microdisplay 100 is used to load monochrome or color images in the full field of view. The first relay optical element group 200 collimates the conical beams from each pixel in the image source plane of the microdisplay 100, forming narrow beam parallel light at different angles. The entrance pupil position of the planar waveguide module 300 coincides with and matches the exit pupil of the first relay optical element group 200; the object-side field of view of the planar waveguide module 300 must match the image-side field of view of the first relay optical element group 200. The planar waveguide module 300 serves as a planar pupil expanding device, and the narrow beam wavefront is coupled into the first coupling optical element 320 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the planar waveguide 310. A specific method of exit pupil expansion is achieved through the redirection optical element 330, and then diffracted by the first coupling optical element 340. At this point, the exit pupil of the planar waveguide module 300 is located in the space on the user side of the first coupling optical element 340. The entrance pupil position of the second relay optical element group 500 coincides with and matches the size of the exit pupil of the planar waveguide module 300. The object-side field of view of the second relay optical element group 500 must match the image-side field of view of the planar waveguide module 300, thereby imaging the exit pupil of the planar waveguide module 300 onto the entrance pupil of the curved holographic waveguide module 400 without sacrificing the field of view. The curved holographic waveguide module 400 is essentially a curved waveguide combiner, where a wide-beam parallel light is coupled in by the second coupling optical element 420 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the curved holographic waveguide 410, ensuring consistent spot sizes on both surfaces in every field of view, achieving tangential distortion-free propagation. Finally, it is diffracted through the second coupling element 430 on the other end surface, forming a virtual image that can be observed by the human eye within a relatively wide exit pupil region. This method enables a large-pupil curved holographic waveguide display device that can be used as part or extended into a freeform curved screen for head-mounted displays, providing users of portable display devices such as smart glasses with a stable and continuous augmented reality visual experience in dynamic scenes. This display method does not rely on large display panels and space-consuming relay optical systems. Instead, it ensures effective expansion of the pupil box by integrating a one-dimensional or two-dimensional pupil-expanding planar waveguide device based on a curved waveguide with a large numerical aperture for modulating beams. This design integrates a smaller microdisplay and relay optical element group, achieving a compact device shape and significantly reducing the manufacturing cost of the head-mounted display.

[0072] Example 3

[0073] An embodiment of the curved holographic waveguide display device with a large pupil box of the present invention, such as... Figure 9As shown, the curved holographic waveguide display device of the large-eye pupil box includes a microdisplay 100, a first relay optical element group 200, a flat waveguide module 300, a curved holographic waveguide module 400, and a second relay optical element group 500.

[0074] This embodiment implements a curved holographic waveguide display method for a large pupil box. The microdisplay 100 is used to load monochrome or color images in the full field of view. The first relay optical element group 200 collimates the conical beams from each pixel in the image source plane of the microdisplay 100, forming narrow beam parallel light at different angles. The entrance pupil position of the planar waveguide module 300 coincides with and matches the exit pupil of the first relay optical element group 200; the object-side field of view of the planar waveguide module 300 must match the image-side field of view of the first relay optical element group 200. The planar waveguide module 300 serves as a planar pupil expanding device, where the narrow beam wavefront is coupled by the first coupling optical element 320 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the planar waveguide 310, and the exit pupil is expanded by a specific method through the redirection optical element 330, before being diffracted out by the first coupling optical element 340. At this time, the exit pupil of the planar waveguide module 300 is located in the space on the side of the first coupled optical element 340 near the curved holographic waveguide module 400. The entrance pupil position of the second relay optical element group 500 coincides with and matches the size of the exit pupil of the planar waveguide module 300; the object-side field of view of the second relay optical element group 500 needs to match the image-side field of view of the planar waveguide module 300, so that the exit pupil of the planar waveguide module 300 is imaged onto the entrance pupil of the curved holographic waveguide module 400 without losing the field of view. The curved holographic waveguide module 400 is essentially a curved waveguide beam combiner, and the wide beam of parallel light is coupled in by the second coupled optical element 420 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the curved holographic waveguide 410, ensuring consistent spot sizes on both surfaces in every field of view, achieving tangential distortion-free propagation. Finally, it is diffracted through the second coupling element 430 on the other end surface, forming a virtual image that can be observed by the human eye within a relatively wide exit pupil region. This method enables a large-pupil curved holographic waveguide display device that can be used as part or extended into a freeform curved screen for head-mounted displays, providing users of portable display devices such as smart glasses with a stable and continuous augmented reality visual experience in dynamic scenes. This display method does not rely on large display panels and space-consuming relay optical systems. Instead, it ensures effective expansion of the pupil box by integrating a one-dimensional or two-dimensional pupil-expanding planar waveguide device based on a curved waveguide with a large numerical aperture for modulating beams. This design integrates a smaller microdisplay and relay optical element group, achieving a compact device shape and significantly reducing the manufacturing cost of the head-mounted display.

[0075] Example 4

[0076] An embodiment of the curved holographic waveguide display device with a large pupil box of the present invention, such as... Figure 10 As shown, the curved holographic waveguide display device of the large-eye pupil box includes a microdisplay 100, a first relay optical element group 200, a planar waveguide module 300, a curved holographic waveguide module 400, and a relay optical element 600.

[0077] The relay optical element 600 is a diffractive optical element, attached to the inner or outer surface of the curved holographic waveguide module 400. As a relay element, it ensures that the exit pupil of the planar waveguide module 300 and the entrance pupil of the curved holographic waveguide module 400 are conjugate. The entrance pupil position of the relay optical element 600 coincides with and is sized to match the exit pupil of the first coupled optical element 340. The object-side field of view of the relay optical element 600 must match the image-side field of view of the first coupled optical element 340. To obtain maximum optical energy, the modulation wavelength and modulation angle of the relay optical element 600 must match the wavelength information of the beam and the propagation angle of the central field of view to achieve maximum diffraction efficiency. The diffractive optical element can be a holographic optical element, a volume holographic optical element, a surface relief grating, or a polarizing grating. The holographic optical element is a holographic recording medium. Commonly used holographic recording media include silver halide emulsion, dichromate gelatin, photoresist, photopolymer, and photothermal conductive plastic.

[0078] The relay optical element 600 incorporates certain holographic structural functions. In the curved holographic waveguide module 400, the relay optical element 600 is attached to the inner or outer surface of one end of the curved waveguide 410. It is typically fabricated using methods such as holographic exposure or holographic printing. The hologram recorded by the relay optical element 600 is formed by the interference of a planar reference light and a planar signal light, both emitted from the inner side of the curved surface and propagating along the outer normal direction of the holographic optical element, under coherence conditions. In the coaxial optical path, the difference between the reference light and the signal light lies in the fact that the signal light undergoes a specific beam shaping process. This enables the volume holographic grating generated by the interference to modulate and reconstruct the light to match the entrance pupil requirements of the curved holographic waveguide module 400.

[0079] This embodiment realizes a curved holographic waveguide display device with a large pupil box. The microdisplay 100 is used to load monochrome or color images in the full field of view. The first relay optical element group 200 collimates the conical beams from each pixel in the image source plane of the microdisplay 100, forming narrow beam parallel light at different angles. The entrance pupil position of the planar waveguide module 300 coincides with and matches the exit pupil of the first relay optical element group 200; the object-side field of view of the planar waveguide module 300 must match the image-side field of view of the first relay optical element group 200. The planar waveguide module 300 serves as a planar pupil expanding device, where the narrow beam wavefront is coupled by the first coupling optical element 320 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the planar waveguide 310, and the exit pupil is expanded by a specific method through the redirection optical element 330, before being diffracted out by the first coupling optical element 340. At this time, the exit pupil of the planar waveguide module 300 is located in the space of the first coupled-out optical element 340 on the user side. The entrance pupil position of the relay optical element 600 coincides with and matches the size of the exit pupil of the planar waveguide module 300; the object-side field of view of the relay optical element 600 needs to match the image-side field of view of the planar waveguide module 300, so that the exit pupil of the planar waveguide module 300 is imaged onto the entrance pupil of the curved holographic waveguide module 400 without losing the field of view. The curved holographic waveguide module 400 is essentially a curved waveguide beam combiner, and the wide beam of parallel light is coupled in by the second coupled-in optical element 420 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the curved holographic waveguide 410, ensuring consistent spot sizes on both surfaces in every field of view, achieving tangential distortion-free propagation. Finally, it is diffracted through the second coupling element 430 on the other end surface, forming a virtual image that can be observed by the human eye within a relatively wide exit pupil region. This method enables a large-pupil curved holographic waveguide display device that can be used as part or extended into a freeform curved screen for head-mounted displays, providing users of portable display devices such as smart glasses with a stable and continuous augmented reality visual experience in dynamic scenes. This display method does not rely on large display panels and space-consuming relay optical systems. Instead, it ensures effective expansion of the pupil box by integrating a one-dimensional or two-dimensional pupil-expanding planar waveguide device based on a curved waveguide with a large numerical aperture for modulating beams. This design integrates a smaller microdisplay and relay optical element group, achieving a compact device shape and significantly reducing the manufacturing cost of the head-mounted display.

[0080] Example 5

[0081] An embodiment of the curved holographic waveguide display device with a large pupil box of the present invention, such as... Figure 11As shown, the curved holographic waveguide display device of the large-eye pupil box includes a microdisplay 100, a first relay optical element group 200, a planar waveguide module 300, a curved holographic waveguide module 400, and a relay optical element 600.

[0082] This embodiment implements a curved holographic waveguide display method for a large pupil box. The microdisplay 100 is used to load monochrome or color images in the full field of view. The first relay optical element group 200 collimates the conical beams from each pixel in the image source plane of the microdisplay 100, forming narrow beam parallel light at different angles. The entrance pupil position of the planar waveguide module 300 coincides with and matches the exit pupil of the first relay optical element group 200; the object-side field of view of the planar waveguide module 300 must match the image-side field of view of the first relay optical element group 200. The planar waveguide module 300 serves as a planar pupil expanding device, where the narrow beam wavefront is coupled by the first coupling optical element 320 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the planar waveguide 310, and the exit pupil is expanded by a specific method through the redirection optical element 330, before being diffracted out by the first coupling optical element 340. At this time, the exit pupil of the planar waveguide module 300 is located in the space on the side of the first coupled optical element 340 near the curved holographic waveguide module 400. The entrance pupil position of the relay optical element 600 coincides with and matches the size of the exit pupil of the planar waveguide module 300; the object-side field of view of the relay optical element 600 needs to match the image-side field of view of the planar waveguide module 300, so that the exit pupil of the planar waveguide module 300 is imaged onto the entrance pupil of the curved holographic waveguide module 400 without losing the field of view. The curved holographic waveguide module 400 is essentially a curved waveguide beam combiner, where a wide beam of parallel light is coupled in by the second coupled optical element 420 on one end surface. The modulated wavefront propagates through total internal reflection within the upper and lower surfaces of the curved holographic waveguide 410, ensuring consistent spot sizes on both surfaces in every field of view, achieving tangential distortion-free propagation. Finally, it is diffracted through the second coupling element 430 on the other end surface, forming a virtual image that can be observed by the human eye within a relatively wide exit pupil region. This method enables a large-pupil curved holographic waveguide display device that can be used as part or extended into a freeform curved screen for head-mounted displays, providing users of portable display devices such as smart glasses with a stable and continuous augmented reality visual experience in dynamic scenes. This display method does not rely on large display panels and space-consuming relay optical systems. Instead, it ensures effective expansion of the pupil box by integrating a one-dimensional or two-dimensional pupil-expanding planar waveguide device based on a curved waveguide with a large numerical aperture for modulating beams. This design integrates a smaller microdisplay and relay optical element group, achieving a compact device shape and significantly reducing the manufacturing cost of the head-mounted display.

[0083] This invention realizes a curved holographic waveguide display method for large-eye pupil boxes.

[0084] Step 1: The microdisplay loads a monochrome or color image across the entire field of view. The first relay optical element group collimates the beams in each field of view. The narrow beam parallel light satisfies the modulation conditions of the planar waveguide module and is fully coupled in.

[0085] Step 2: The planar waveguide module achieves one-dimensional or two-dimensional exit pupil expansion by following a specific pupil expansion method, and couples out a wide beam of parallel light.

[0086] Step 3: Based on the different spatial positions of the exit pupil of the planar waveguide module, select appropriate relay optical elements or relay optical element groups to modulate the wide beam wavefront to meet the modulation conditions and entrance pupil requirements of the curved holographic waveguide module, thereby achieving coupling.

[0087] Step 4: The curved holographic waveguide module guides the tangential propagation of the wavefront and couples out a distortion-free full-field image. The resulting virtual image can be perfectly integrated into the human eye with the real environment over a wide area.

[0088] Between steps three and four, the method further includes: selecting a relay optical element or a second relay optical element group according to the position of the exit pupil of the planar waveguide module, and modulating the wide beam wavefront to meet the modulation conditions and entrance pupil requirements of the curved holographic waveguide module.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above. Although the present invention 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. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A curved holographic waveguide display device with a large pupil box, characterized in that, include: Microdisplay (100) for loading monochrome or color images across the entire field of view; The first relay optical element group (200) is disposed in front of the microdisplay (100) to collimate the conical beam emitted by the microdisplay (100), form parallel beams of narrow beams at different angles, and ensure that the propagation direction of different wavelengths of light generated by the same pixel is consistent, forming a unified field of view; The planar waveguide module (300), as a planar waveguide module, is used to receive the narrow beam parallel light and achieve one-dimensional or two-dimensional exit pupil expansion through total internal reflection, redirection and coupling, forming a wide beam parallel light with a large exit pupil. Its exit pupil coincides with the entrance pupil position of the curved holographic waveguide module (400) and the size matches, and the field of view corresponds to each other. A curved holographic waveguide module (400) is used to receive the wide beam parallel light, which propagates and is coupled out through total internal reflection to form a virtual image that can be observed in the large exit pupil region. The curved holographic waveguide module (400) includes a curved waveguide (410), a second coupling optical element (420), and a second coupling optical element (430). The wide beam parallel light from the planar waveguide module (300) is coupled in by the second coupling optical element (420), propagates through total internal reflection in the curved waveguide (410), and is diffracted out through the second coupling optical element (430) to form a distortion-free full-field image. The two surfaces of the curved waveguide (410) have the same center of curvature and different radii of curvature. The establishment positions of the construction points of the second coupling optical element (420) and the second coupling optical element (430) are accurately calculated based on the surface shape of the curved waveguide (410) to achieve image transmission without distortion accumulation when propagating tangentially along the curved waveguide.

2. The curved holographic waveguide display device with a large pupil box according to claim 1, characterized in that, It also includes a second relay optical element group (500) disposed between the planar waveguide module (300) and the curved holographic waveguide module (400) to ensure the conjugate relationship between the exit pupil of the planar waveguide module (300) and the entrance pupil of the curved holographic waveguide module (400), that is, the exit pupil of the planar waveguide module (300) is imaged onto the entrance pupil of the curved holographic waveguide module (400).

3. The curved holographic waveguide display device with a large pupil box according to claim 2, characterized in that, The second relay optical element group (500) includes a first relay lens (510) and a second relay lens (520), and the optical axes of the first relay lens (510) and the second relay lens (520) coincide. The rear focal point of the first relay lens (510) coincides with the front focal point of the second relay lens (520), and the second relay optical system (500) coincides with the optical axes of the first output optical element (340) and the second input optical element (420).

4. The curved holographic waveguide display device with a large pupil box according to claim 1, characterized in that, It also includes a relay optical element (600) attached to the inner or outer surface of the curved holographic waveguide module (400) to ensure that the exit pupil of the planar waveguide module (300) and the entrance pupil of the curved holographic waveguide module (400) are conjugate.

5. The curved holographic waveguide display device with a large pupil box according to any one of claims 1-4, characterized in that, The planar waveguide module (300) is arranged radially and interspersed with the curved holographic waveguide module (400) in the front and rear, and tangentially. The planar waveguide module (300) includes a planar waveguide (310), a first coupled-in optical element (320), a redirected optical element (330), and a first coupled-out optical element (340). The narrow beam parallel light from the first relay optical element group (200) is coupled into the first coupled-in optical element (320), propagates through total internal reflection in the planar waveguide (310), and achieves exit pupil expansion through the redirected optical element (330), and is then diffracted out by the first coupled-out optical element (340).

6. The curved holographic waveguide display device with a large pupil box according to claim 5, characterized in that, The first coupled optical element (340) modulates the parallel beams of each wide field of view in the optical field to converge towards the parallel beams of the central field of view, forming the exit pupil, which together constitutes the entrance pupil of the curved holographic waveguide module (400).

7. The second coupling optical element (420) and the second coupling optical element (430) according to claim 5, characterized in that, The second coupling optical element (420) and the second coupling optical element (430) can be composed of any of the following forms: a layer of three-color composite diffraction optical element; a layer of two-color composite diffraction optical element and a layer of monochromatic diffraction optical element with a high distribution superposition; three layers of different monochromatic diffraction optical elements with a high distribution superposition; and a reasonable selection based on diffraction efficiency and diffraction uniformity.

8. A display method using a curved holographic waveguide display device with a large pupil box as described in any one of claims 1-7, characterized in that, include: Step 1: Load a monochrome or color image across the entire field of view via the microdisplay (100); Step 2: Collimate the beams from each field of view of the microdisplay (100) using the first relay optical element group (200) to form a narrow beam of parallel light; Step 3: Expand the exit pupil in one or two dimensions using a planar waveguide module (300) to couple out a wide beam of parallel light; Step 4: Use the curved holographic waveguide module (400) to guide the tangential propagation of the wavefront and couple out a distortion-free full-field image. The resulting virtual image can be perfectly integrated into the human eye with the real environment in a wide area.

9. The display method according to claim 8, characterized in that, Between steps 3 and 4, the method further includes: selecting a relay optical element (600) or a second relay optical element group (500) based on the position of the exit pupil of the planar waveguide module (300) to modulate the wide beam wavefront to meet the modulation conditions and entrance pupil requirements of the curved holographic waveguide module.

Images