A multi-viewpoint retinal projection augmented reality near-eye display optical system

Abstract

The present invention provides a multi-viewpoint retinal projection augmented reality near-eye display optical system. The illumination light waves radiated by each light-emitting sub-unit on the illumination source form a dense viewpoint array with a two-dimensional distribution on the pupil plane of the human eye. The range of the viewpoint array formed by the display light waves is larger than the movement range of the human pupil. Therefore, at any pupil position, there is a viewpoint that can enter the pupil center, so that the image source is directly projected onto the human eye retina through the display light wave corresponding to the viewpoint to form a clear image. This process does not rely on the focusing function of the lens. Regardless of the distance the human eye is focused on, the virtual image can always be clearly formed on the retina, achieving a wide range of depth of field. External ambient light can be directly transmitted from the optical combiner into the human eye for formation, realizing optical perspective display.

Description

Technical Field

[0001] The present invention belongs to the field of near-eye display technology, and in particular relates to a multi-viewpoint retinal projection augmented reality near-eye display optical system. Background Art

[0002] In existing augmented reality (AR) near-eye display optical systems, the display beam must be focused by the human eye lens to form a clear image on the retina, resulting in a very limited depth of field for observing virtual images. When the human eye lens deviates from this focused state, the virtual image appears blurry. When this system is used for binocular display, there is a mismatch between the focusing distance of a single eye and the vergence distance of both eyes, resulting in a vergence accommodation conflict (VAC), which can cause visual fatigue and discomfort. To expand the depth of field of traditional near-eye display systems and address the VAC issue, a retinal projection-type display solution can be used.

[0003] The retinal projection display system focuses the display beam loaded with image information onto a viewpoint located in the center of the human pupil, a viewpoint much smaller than the diameter of the human pupil. The display beam passes directly through this viewpoint and is projected onto the retina to form an image, allowing the human visual system to perceive the virtual image information. This imaging process is independent of the focusing function of the human eye lens. In any focusing state of the lens, the virtual image can always be clearly imaged on the retina, achieving a wide range of depth of field extension. For refractive errors of the lens, such as myopia, hyperopia, and astigmatism, the retinal projection display solution can present clear virtual image information to the human eye without the user having to wear specially customized corrective lenses, which is conducive to adapting to a wider user group. At the same time, because the imaging process of the virtual image on the human retina does not rely on the focusing function of the lens, retinal projection display can effectively solve the VAC problem.

[0004] However, the eyebox size provided by retinal projection display systems is quite small. If the pupil slightly deviates from the viewpoint, the virtual image appears incomplete or even disappears completely, significantly limiting the application of retinal projection displays. Existing methods for expanding the eyebox of retinal projection display systems utilize optical elements such as beamsplitter arrays, multiplexed holographic optical elements, geometric phase lenses, polarization gratings, and Dammann gratings to simultaneously and statically replicate multiple discrete viewpoints in space. However, due to changes in ambient light intensity, the increase or decrease in the diameter of the human pupil can cause multiple viewpoints to enter the human pupil at the same time, or no viewpoint to enter the human pupil, which can cause multiple images or visual blind spots. Another method is to dynamically move the viewpoint in space, using a polarization control element to achieve dynamic viewpoint movement by changing the polarization state of the display light beam. However, this method can only achieve a small number of viewpoints and cannot continuously cover the range of human eye movement. In addition, the viewpoint position can be dynamically deflected using a mechanical deflection mirror or a moving device, but this method introduces complex mechanical devices, resulting in a large volume and weight of the optical system structure and low practicality. Even if an LED array can be used as an illumination source, each LED sub-light-emitting unit corresponds to a viewpoint. Dynamic viewpoint movement in space can be achieved by dynamically switching different LED sub-light-emitting units. However, the size of a single LED sub-light-emitting unit is large, equivalent to an extended light source, and the viewpoint formed by it in the human pupil plane is large, which cannot achieve the expansion of the depth of field range of the virtual image. The above-mentioned existing technical solutions for the eye box of the extended retinal projection display system still have significant limitations, such as only being able to produce a small number of discrete viewpoint arrays, using complex mechanical deflection devices in the system, or the viewpoints formed are large in size. Summary of the Invention

[0005] To solve the above problems, the present invention provides a multi-viewpoint retinal projection augmented reality near-eye display optical system, so that at any pupil position, there is a viewpoint that can enter the pupil center, and the display light wave corresponding to the viewpoint is directly projected onto the human eye retina for imaging, so that the virtual image information can be clearly perceived by the human eye visual system.

[0006] A multi-viewpoint retinal projection augmented reality near-eye display optical system includes an illumination source 11, a first shaping component, an image source 12 to be displayed near the eye, a polarizing beam splitter prism 13, a second shaping component, an optical combiner 14, an eye-tracking camera 15, and a processing module. The illumination source 11 includes a plurality of array-arranged and independently controllable sub-light-emitting units, each of which radiates a beam of illumination light waves.

[0007] The illumination light waves emitted by each sub-light-emitting unit are regulated by the first shaping component and then incident on the polarization beam splitter prism 13. The illumination light waves are reflected by the beam splitting surface of the polarization beam splitter prism 13 and then incident on the image source 12. The image source 12 adds image information to the incident illumination light waves to obtain display light waves. After being reflected back by the image source 12 to the polarization beam splitter prism 13, the display light waves are directly transmitted from the beam splitting surface to the second shaping component. After being regulated by the second shaping component, they are projected from an off-axis position to the optical combiner 14. The optical combiner 14 focuses the display light waves in the form of a two-dimensionally distributed viewpoint array onto the human eye pupil plane, and the range of the viewpoint array formed by the display light waves is larger than the range of movement of the human eye pupil.

[0008] When near-eye display is required, the eye tracking camera 15 is used to obtain the pupil center position in real time; the processing module determines the sub-light-emitting units that need to be lit based on the pupil center position, and the lit sub-light-emitting units form corresponding viewpoints in the human eye pupil, so that the image source 12 is imaged on the retina.

[0009] Furthermore, the processing module determines the sub-light-emitting units that need to be lit according to the center position of the pupil as follows:

[0010] The two-dimensional array of sub-light emitting units and the two-dimensional viewpoint array of display light waves are both constructed with the center of the array as the origin to construct a rectangular coordinate system. It is assumed that the position coordinate of the pupil center is ( , ), then the theoretical position coordinates of the sub-light-emitting unit that needs to be lit are ( , ),in, is the lateral magnification of the entire optical system, is the longitudinal magnification of the entire optical system;

[0011] will be compared with the theoretical position coordinates ( , ) The sub-light-emitting unit that is closest in position is used as the sub-light-emitting unit that is finally lit.

[0012] Furthermore, the first shaping assembly includes a first collimating lens 21 and a first reflector 31 coaxial with the illumination source 11;

[0013] The illumination light waves radiated by the sub-light emitting units are focused by the first collimating lens 21 to obtain collimated illumination light waves, and the collimated illumination light waves are then incident on the polarization beam splitting prism 13 via the first reflector 31 .

[0014] Furthermore, the second shaping assembly includes a second collimating lens 22, a second reflector 32, and a third reflector 33, wherein the third reflector 33 is located off-axis with respect to the optical combiner 14. Simultaneously, the image source 12, the polarizing beam splitter prism 13, the second collimating lens 22, and the second reflector 32 are located in a coaxial optical path and are all located off-axis with respect to the third reflector 33. The vertical distance between the third reflector 33 and the second reflector 32 should ensure that the third reflector 33 does not block the display light waves.

[0015] The display light wave is transmitted from the splitting surface of the polarization beam splitting prism 13 to the second collimating lens 22 for collimation to obtain a collimated display light wave; the collimated display light wave is reflected twice by the second reflector 32 and the third reflector 33 in sequence to the optical combiner 14 .

[0016] Furthermore, the illumination light waves radiated by each sub-light-emitting unit of the illumination source 11 completely fill the effective use area of ​​the image source 12, and the effective use area of ​​the image source 12 is rectangular.

[0017] Furthermore, each sub-light-emitting unit of the illumination source 11 can be independently controlled, and each sub-light-emitting unit of the illumination source 11 corresponds to a viewpoint that converges on the pupil plane.

[0018] Further, the illumination source 11 is an LCD panel, a Micro-LED panel or a Micro-OLED panel;

[0019] The illumination light waves radiated by each sub-light-emitting unit of the illumination source 11 are monochromatic illumination light waves or polychromatic illumination light waves, and the illumination light waves are all perpendicular to the plane where the image source 12 is located.

[0020] Furthermore, the incident angles of the illumination light waves radiated by the sub-light-emitting units at different positions on the illumination source 11 on the image source 12 are different; for the sub-light-emitting units at the edge positions of the illumination source 11, the incident angles of the illumination light waves radiated by them on the image source 12 are the largest, and the maximum incident angle of the collimated illumination light waves incident on the image source 12 is not greater than 12 degrees.

[0021] Furthermore, each pupil center position corresponds to a viewpoint, and the spot size of each viewpoint is less than 0.1 mm.

[0022] Furthermore, the optical combiner 14 includes a diffraction grating 141 and a base layer 142 for supporting the diffraction grating 141;

[0023] The diffraction grating 141 is a reflective holographic grating or a relief grating. The diffraction grating 141 diffracts the illumination light waves radiated by different sub-light-emitting units on the illumination source 11 and projected onto its surface to a viewpoint array located on the pupil plane.

[0024] Beneficial effects:

[0025] The present invention provides a multi-viewpoint retinal projection augmented reality near-eye display optical system, in which the illumination light waves radiated by each light-emitting sub-unit on the illumination source form a dense viewpoint array with a two-dimensional distribution on the pupil plane of the human eye, and the range of the viewpoint array formed by the display light waves is larger than the movement range of the human eye pupil, so that at any pupil position, there is a viewpoint that can enter the pupil center, so that the image source is directly projected onto the human eye retina through the display light wave corresponding to the viewpoint to form a clear image; this process does not rely on the focusing function of the lens, and no matter what distance the human eye is focused on, the virtual image can always be clearly formed on the retina, achieving a wide range of depth of field; external ambient light can be directly transmitted from the optical combiner into the human eye for formation, realizing optical perspective display; at the same time, the viewpoint array covers the movement range of the human eye pupil, providing theoretical support for setting up a large-sized eye box; the display light wave corresponding to each viewpoint has a large aperture angle, which can realize a large field angle display of the virtual image. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the augmented reality near-eye display optical system provided by the present invention;

[0027] Figure 2 Schematic diagram of the optical path of the augmented reality near-eye display optical system provided by an embodiment of the present invention;

[0028] Figure 3 is the position of the illumination optical assembly 41 when the beam splitting surface 131 is rotated 45 degrees counterclockwise around the x-axis;

[0029] Figure 4 is the position of the illumination optical assembly 41 when the beam splitting surface 131 rotates 45 degrees clockwise around the x-axis;

[0030] Figure 5 is the position of the illumination optical assembly 41 when the beam splitting surface 131 is rotated 45 degrees counterclockwise around the y-axis;

[0031] Figure 6 is the position of the illumination optical assembly 41 when the beam splitting surface 131 rotates 45 degrees clockwise around the y-axis;

[0032] Figure 7 It is the MTF curve diagram of the central viewpoint and the edge viewpoint of the formed viewpoint array;

[0033] Figure 8 is the spot size of the 11*11 viewpoint array sampled on the pupil plane;

[0034] Figure 9It is the spot size focused by the ideal lens of the illumination light wave incident on the image source 12 corresponding to the 11*11 viewpoint array sampled on the pupil plane. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0036] The present invention aims to provide an augmented reality near-eye display optical system with a large depth of field, a large eye box, and a large field of view. Figure 1 As shown, it includes an illumination source 11, a first shaping component, an image source 12 to be displayed near the eye to the human eye, a polarization beam splitter prism 13, a second shaping component, an optical combiner 14, an eye tracking camera 15, and a processing module; wherein the illumination source 11 includes a plurality of array-arranged and independently controllable sub-light-emitting units, and each sub-light-emitting unit radiates a beam of illumination light waves;

[0037] The illumination light waves emitted by each sub-light-emitting unit are regulated by the first shaping component and then incident on the polarization beam splitter prism 13. The illumination light waves are reflected by the beam splitting surface of the polarization beam splitter prism 13 and then incident on the image source 12. The image source 12 adds image information to the incident illumination light waves to obtain display light waves. After being reflected back by the image source 12 to the polarization beam splitter prism 13, the display light waves are directly transmitted from the beam splitting surface to the second shaping component. After being regulated by the second shaping component, they are projected from an off-axis position to the optical combiner 14. The optical combiner 14 focuses the display light waves in the form of a two-dimensionally distributed viewpoint array onto the human eye pupil plane, and the range of the viewpoint array formed by the display light waves is larger than the range of movement of the human eye pupil.

[0038] When near-eye display is required, the eye tracking camera 15 is used to obtain the pupil center position in real time; the processing module determines the sub-light-emitting units that need to be lit based on the pupil center position, and the lit sub-light-emitting units form corresponding viewpoints in the human eye pupil, so that the image source 12 is imaged on the retina.

[0039] The processing module determines the sub-light-emitting units that need to be lit according to the center position of the pupil as follows:

[0040] The two-dimensional array of sub-light emitting units and the two-dimensional viewpoint array of display light waves are both constructed with the center of the array as the origin to construct a rectangular coordinate system. It is assumed that the position coordinate of the pupil center is ( , ), then the theoretical position coordinates of the sub-light-emitting unit that needs to be lit are ( , ),in, is the lateral magnification of the entire optical system, is the longitudinal magnification of the entire optical system; and the theoretical position coordinates ( , ) The sub-light-emitting unit that is closest in position is used as the sub-light-emitting unit that is finally lit.

[0041] It should be noted that the absolute value of the magnification of the optical system is equal to the image plane size divided by the object plane size. In this embodiment, the image plane size is the size of the illumination source 11, and the object plane size is the size of the range of the viewpoint array formed. Relative to the local coordinate system located in the pupil plane and the illumination source plane, the object image of the optical system in this embodiment is inverted, and the magnification is negative. The magnification of the optical system in this embodiment is equal to the position coordinate mapping coefficient of the viewpoint array and the illumination source light-emitting sub-unit. 、 As the human eye rotates, any pupil center position can correspond to a viewpoint position. The eye tracking camera captures the pupil center position of the human eye in real time. Based on the captured pupil center position, the viewpoint coordinates corresponding to the pupil center position are selected ( x P , y P ). Based on the selected viewpoint position coordinates ( x P , y P ) and mapping coefficients α , β , synchronously illuminate the illumination source 11 on the plane with the mapping coordinates ( x S , y S )= ( , )The closest light-emitting subunit.

[0042] Specifically, the illumination light waves emitted by each light-emitting subunit of the illumination source, after being manipulated by the image source, collimating lens, reflector, and optical combiner, form a densely distributed two-dimensional array of viewpoints on the pupil plane. The image source loads image information onto the light waves, while the collimating lens, reflector, and optical combiner manipulate the wavefront shape of the display beam. The viewpoint array covers the range of motion of the human pupil, providing a large eyebox. The display beam corresponding to each viewpoint has a large aperture angle, enabling a wide field of view for displaying virtual images. Each viewpoint is independently controlled by each light-emitting subunit of the illumination source, and its size is significantly smaller than the diameter of the human pupil. Each viewpoint corresponds to a pupil center position. As the pupil moves, the eye-tracking camera captures the pupil center position in real time and synchronously updates the corresponding light-emitting subunit of the illumination source, ensuring that at any pupil position, a viewpoint can enter the pupil center. The display beam corresponding to this viewpoint is directly projected onto the retina, creating an image, and the virtual image information can be perceived by the human visual system. This process does not rely on the focusing function of the lens. No matter what distance the human eye focuses on, the virtual image can always be clearly imaged on the retina, achieving a wide depth of field; external ambient light can be directly transmitted from the optical combiner into the human eye for imaging, realizing optical perspective display.

[0043] Furthermore, the first shaping component includes a first collimating lens 21 and a first reflector 31 coaxial with the illumination source 11; the second shaping component includes a second collimating lens 22, a second reflector 32, and a third reflector 33; that is, the illumination light waves radiated by each sub-light-emitting unit of the illumination source 11 are regulated by the first collimating lens 21 and the reflector 31 and then incident on the polarization beam splitter prism 13; the illumination light waves are reflected by the beam splitting surface 131 of the polarization beam splitter prism 13 and then incident on the image source 12; the image source 12 loads image information on the incident illumination light waves and reflects them back to the polarization beam splitter prism 13; the display light waves loaded with image information are directly transmitted through the beam splitting surface 131, and then, after being regulated by the second collimating lens 22 and the reflectors 32 and 33, are projected from an off-axis position to the optical combiner 14; the optical combiner 14 focuses the display light waves onto a two-dimensionally distributed viewpoint array on the pupil plane of the human eye.

[0044] It should be noted that, as a preferred embodiment of the present invention, the aperture stop of the optical system is located on the incident surface of the image source 12; the illumination light waves radiated by each sub-light-emitting unit of the illumination source 11 completely fill the effective use area of ​​the image source 12; the effective use area of ​​the image source 12 is rectangular;

[0045] As a preferred embodiment of the present invention, the image source 12 is a reflective spatial light modulator or an LCoS display; the image source 12 adds image information to the incident illumination light wave and reflects the illumination light wave;

[0046] As a preferred solution of the present invention, each sub-light-emitting unit of the illumination source 11 can be independently controlled; each sub-light-emitting unit of the illumination source 11 corresponds to a viewpoint that converges on the pupil plane;

[0047] As a preferred embodiment of the present invention, the illumination source 11 is a self-luminous display panel, including but not limited to an LCD panel, a Micro-LED panel, and a Micro-OLED panel. The illumination light waves radiated by each sub-light-emitting unit of the illumination source 11 are perpendicular to the plane where the image source 11 is located. The illumination source 11 can radiate monochromatic illumination light waves to achieve monochromatic display, or radiate polychromatic illumination light waves to achieve color display. For the illumination source 11 radiating polychromatic illumination light waves, each light-emitting sub-unit simultaneously includes light-emitting units for red, green, and blue channels. The light-emitting units of different color channels illuminate the image source 12 in a high-frequency time-sequential manner.

[0048] As a preferred embodiment of the present invention, in order to realize optical see-through augmented reality display, the reflector 33 is located off-axis of the optical combiner 14; the distance between the reflector 33 and the optical combiner 14 in the y direction should ensure that the reflector 33 does not block the external ambient light;

[0049] The image source 12, the polarizing beam splitter prism 13, the second collimating lens 22, and the reflector 32 are located in a coaxial optical path; the image source 12, the polarizing beam splitter prism 13, the second collimating lens 22, and the reflector 32 are all located off-axis of the reflector 33; the distance between the reflectors 33 and 32 in the y direction should ensure that the reflector 33 does not block the display light beam;

[0050] The illumination source 11, the first collimating lens 21, and the reflector 31 are located in a coaxial optical path to ensure that the illumination light wave energy radiated by the illumination source 11 can fully enter the display system to ensure display brightness. The illumination source 11, the first collimating lens 21, and the reflector 31 constitute an illumination optical assembly 41 for the image source 12. The illumination optical assembly 41 is located off-axis from the image source 12.

[0051] The image source 12, the second collimating lens 22, and the reflector 31 should maintain a certain distance from the outer surface of the polarization beam splitting prism 13 to avoid structural interference;

[0052] As a preferred embodiment of the present invention, the reflector 32 and the reflector 33 deflect the optical path and project the display light wave from an off-axis position to the optical combiner 14 to realize an optical see-through near-eye display of the off-axis projection type;

[0053] As a preferred embodiment of the present invention, the reflector 31 reflects the illumination light waves radiated by the illumination source 11 to the polarization beam splitter prism 13;

[0054] As a preferred embodiment of the present invention, the first collimating lenses 21 and 22 are aspherical lenses or free-form surface lenses; the reflectors 31, 32, and 33 are aspherical reflectors or free-form surface reflectors;

[0055] As a preferred embodiment of the present invention, the splitting surface 131 of the polarization splitting prism 13 has polarization selectivity; the splitting surface 131 reflects the illumination light waves radiated by the illumination source 11; the splitting surface 131 transmits the display light waves reflected by the image source 12 and loaded with image information;

[0056] The effective light transmission area of ​​the light splitting surface 131 should completely cover the illumination light waves radiated by different sub-light emitting units of the illumination source 11 and reflected on its surface by the reflector 31;

[0057] As a preferred embodiment of the present invention, the rotation angle of the beam splitter 131 determines the position of the illumination optical assembly 41; the beam splitter 131 can rotate counterclockwise or clockwise around the x-axis or the y-axis;

[0058] Taking the local coordinate system of the image source 12 as a reference, wherein the local z-axis is perpendicular to the plane where the image source 12 is located, the illumination optical group 41 can be located on the +y-axis side, the -y-axis side, the +x-axis side, and the -x-axis side of the image source 12;

[0059] As a preferred embodiment of the present invention, the illumination light waves radiated by each sub-light-emitting unit on the illumination source 11 are regulated by the first collimating lens 21 and the reflector 31, and then reflected by the beam splitting surface 131, and then incident on the image source 12 in the form of collimated light waves;

[0060] As a preferred embodiment of the present invention, the incident angles of the illumination light waves radiated by the sub-light-emitting units at different positions on the illumination source 11 on the image source 12 are different; the incident angles of the illumination light waves radiated by the sub-light-emitting units at the edge positions of the illumination source 11 on the image source 12 are the largest; the maximum incident angle of the collimated illumination light waves incident on the image source 12 is no greater than 12 degrees;

[0061] As a preferred embodiment of the present invention, the light waves reflected by the image source 12 are directly transmitted from the beam splitting surface 131 and are regulated by the second collimating lens 22 to form an intermediate image plane in space, thereby significantly reducing the system volume.

[0062] As a preferred embodiment of the present invention, the optical combiner 14 converges the display light waves projected onto its surface to the viewpoint array located on the pupil plane; the optical combiner 14 has a high optical transmittance to the external ambient light, so as to achieve a good optical perspective effect of the external scene;

[0063] As a preferred embodiment of the present invention, the optical combiner 14 is perpendicular to the z-axis; the optical combiner 14 includes a diffraction grating 141 and a base layer 142;

[0064] As a preferred embodiment of the present invention, the diffraction grating 141 is a reflective holographic grating or a relief grating; the diffraction grating 141 diffracts the illumination light waves radiated by different sub-light-emitting units on the illumination source 11 projected onto its surface to an array of viewpoints located on the pupil plane;

[0065] As a preferred embodiment of the present invention, the diffraction grating 141 is characterized by a phase function; the phase function can be described by mathematical forms such as XY polynomials, Zernike polynomials, and NURBS polynomials;

[0066] As a preferred embodiment of the present invention, the base shape of the base layer 142 is a plane; the thickness of the base layer 142 is less than 3 mm; the material of the base layer 142 can be resin or glass;

[0067] As a preferred embodiment of the present invention, the range of the viewpoint array formed on the pupil plane covers the movement range of the human pupil; in the viewpoint array, each viewpoint corresponds to a pupil center position; the spot size of each viewpoint is less than 0.1 mm, which is much smaller than the diameter of the human pupil;

[0068] As a preferred embodiment of the present invention, the number of viewpoints is equal to the number of light-emitting subunits of the illumination source 11, and each viewpoint corresponds to a light-emitting subunit on the illumination source 11; each viewpoint can be independently controlled by a light-emitting subunit of the illumination source 11;

[0069] As a preferred embodiment of the present invention, the eye-tracking camera 15 operates synchronously with the illumination source 11 and the image source 12. As the human pupil moves, the eye-tracking camera 15 acquires the pupil center position in real time. At any pupil position, the corresponding light-emitting subunit on the illumination source 11 is synchronously refreshed, so that the corresponding viewpoint is located at the center of the pupil. The display light beam carrying the image information passes through the viewpoint located at the center of the pupil and is directly projected onto the human eye's retina for imaging. The human eye's visual system can perceive the virtual image information. This process is independent of the focusing function of the human eye lens. Regardless of the distance at which the human eye is focused, the virtual image can always be clearly imaged on the retina, achieving a wide range of depth of field extension.

[0070] As a preferred embodiment of the present invention, the aperture angle of the display light beam converging on the viewpoint corresponds to the field angle of the viewpoint;

[0071] As a preferred solution of the present invention, the distance between the viewpoint array and the optical combiner 14 in the z direction corresponds to the exit pupil distance of the near-eye display system.

[0072] Furthermore, if Figure 2As shown, the illumination source 11 is selected as a Micro-OLED display panel, and the size of the light-emitting sub-unit is 8 μm. The size of the light-emitting sub-unit is on the micron scale, and it is not an extended light source. The illumination light wave radiated by the light-emitting sub-unit can be considered as a quasi-spherical wave. The illumination light wave radiated by the light-emitting sub-unit is perpendicular to the plane where the illumination source 11 is located.

[0073] The image source 12 is selected as an LCoS display with a resolution of 1920*1080 and an effective use area of ​​15.36mm*8.64mm ( x * y );

[0074] The effective light transmission area of ​​the splitting surface 131 of the polarization splitting prism 13 completely covers the illumination light waves radiated by different sub-light-emitting units of the illumination source 11 reflected on its surface by the reflector 31; the size of the polarization splitting prism 13 is 25.4mm*25.4mm*25.4mm ( x * y*z ), material is K9;

[0075] The illumination source 11, the first collimating lens 21, and the reflector 31 constitute an illumination optical assembly 41 of the image source 12; the illumination optical assembly 41 is located at an off-axis position of the image source 12; the rotation angle of the beam splitting surface 131 of the polarization beam splitting prism 13 determines the position of the illumination optical assembly 41. x When the axis is rotated 45 degrees counterclockwise, the illumination optical group 41 is located at the image source 12. y Axis side, such as Figure 3 As shown; when the light splitting surface 131 is around x When the axis is rotated 45 degrees clockwise, the illumination optical group 41 is located at the + y Axis side, such as Figure 4 As shown; when the light splitting surface 131 is around y When the axis is rotated 45 degrees counterclockwise, the illumination optical group 41 is located at the + x Axis side, such as Figure 5 As shown; when the light splitting surface 131 is around y When the axis is rotated 45 degrees clockwise, the illumination optical group 41 is located at the image source 12. x Axis side, such as Figure 6 As shown;

[0076] The light splitting surface 131 in the embodiment provided by the present invention is around x The axis is rotated 45 degrees counterclockwise, and the illumination optical group 41 is located at the - yAxis side. The spherical illumination light waves radiated by each sub-light-emitting unit of the illumination source 11 are regulated by the first collimating lens 21 and the reflector 31 before being incident on the polarization beam splitter prism 13. The illumination light waves are reflected by the beam splitting surface 131 of the polarization beam splitter prism 13 before being incident on the image source 12. The image source 12 loads image information onto the incident illumination light waves and reflects them back to the polarization beam splitter prism 13. The display light waves loaded with image information are directly transmitted through the beam splitting surface 131, and then, after being regulated by the second collimating lens 22 and the reflectors 32 and 33, are projected from an off-axis position to the optical combiner 14. The optical combiner 14 focuses the display light waves onto a two-dimensionally distributed viewpoint array on the pupil plane of the human eye.

[0077] The surfaces of the first collimating lens 21 are 212 and 211 respectively, and the surfaces of the second collimating lens 22 are 222 and 221 respectively;

[0078] Table 1 Position coordinates of each surface, relative to the coordinate system at the center of the pupil plane

[0079]

[0080] The phase function of the diffraction grating 141 is described by an XY polynomial, as shown below:

[0081]

[0082] in, λ c is the preparation wavelength of the diffraction grating, A m,n Polynomial coefficients, ( x , y ) are local coordinates of the substrate surface of the diffraction grating 141;

[0083] Table 2 Phase function characterizing the diffraction grating 141 ϕ ( x , y )

[0084]

[0085] The first collimating lens 21 and the second collimating lens 22 are free-form surface lenses made of E48R. The reflectors 31, 32, and 33 are free-form surface reflectors made of aluminum. The shape of the free-form surface is described by an XY polynomial, as shown in the following formula:

[0086]

[0087] in c is the inverse of the radius of curvature, k is the quadratic constant, A i,jare the polynomial coefficients, ( x , y ) are local coordinates of the substrate surface;

[0088] Table 3 Surface shape coefficients of various surfaces

[0089]

[0090] The viewpoint array formed by the near-eye display optical system provided by the embodiment of the present invention on the pupil plane has a range of 6mm*6mm; the viewpoint array and the optical combiner 14 are z The distance interval in the direction is 60mm;

[0091] The number of light-emitting subunits of the illumination source 11 corresponding to the viewpoint array formed within the range of 6mm*6mm on the pupil plane is 1800*1800; that is, the number of viewpoints formed on the pupil plane is 1800*1800;

[0092] In the range of 6mm*6mm on the pupil plane, the MTF curves of the sampled central viewpoint and edge viewpoint are as follows: Figure 7 As shown;

[0093] Table 4 Field of view angles of the sampled central viewpoint and edge viewpoints:

[0094]

[0095] In the 6mm*6mm range on the pupil plane, the RMS spot size of the sampled 11*11 viewpoint array is as follows: Figure 8 The average RMS spot size of each sampled viewpoint is less than 3.5 μm, which is much smaller than the diameter of the human pupil.

[0096] First collimating lens 21 and reflector 31 control the illumination light waves emitted by each sub-light-emitting unit on illumination source 11. After reflection from beam splitter 131, the light waves are incident on image source 12 in the form of collimated illumination light waves. To evaluate the collimation of the illumination light waves, an ideal lens is placed on the plane where image source 12 is located. The size of the spot focused by the ideal lens can be used to evaluate the collimation of the illumination light waves. The smaller the spot size, the higher the collimation of the illumination light waves.

[0097] In the range of 6mm*6mm on the pupil plane, the RMS spot size of the illumination light wave incident on the image source 12 corresponding to the sampled 11*11 viewpoint array and focused by the ideal lens is as follows: Figure 9 As shown, the average RMS spot size of the illumination light wave incident on the image source 12 focused by the ideal lens is less than 0.2 mm, achieving a high degree of collimation of the illumination light wave;

[0098] In summary, the illumination light waves emitted by each light-emitting subunit of the illumination source, after being manipulated by the image source, collimating lens, reflector, and optical combiner, form a densely distributed two-dimensional array of viewpoints on the pupil plane. The image source loads image information onto the light waves, while the collimating lens, reflector, and optical combiner manipulate the wavefront shape of the display beam. The viewpoint array covers the range of motion of the human pupil, providing a large eyebox. The display beam corresponding to each viewpoint has a large aperture angle, enabling the display of virtual images with a wide field of view. Each viewpoint is independently controlled by each light-emitting subunit of the illumination source, and its size is much smaller than the diameter of the human pupil. Each viewpoint corresponds to a pupil center position. As the human pupil moves, the eye-tracking camera captures the pupil center position in real time and synchronously updates the corresponding light-emitting subunit of the illumination source, ensuring that at any pupil position, a viewpoint can enter the pupil center. The display beam corresponding to this viewpoint is directly projected onto the human retina as an image, allowing the virtual image information to be perceived by the human visual system. This process does not rely on the focusing function of the lens. No matter what distance the human eye focuses on, the virtual image can always be clearly imaged on the retina, achieving a wide depth of field; external ambient light can be directly transmitted from the optical combiner into the human eye for imaging, realizing optical perspective display.

[0099] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may of course make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A multi-viewpoint retinal projection augmented reality near-eye display optical system, characterized in that: The invention comprises an illumination source (11), a first shaping component, an image source (12) to be displayed near the eye to the human eye, a polarization beam splitter prism (13), a second shaping component, an optical combiner (14), an eye tracking camera (15), and a processing module; wherein the illumination source (11) comprises a plurality of array-arranged and independently controllable sub-light-emitting units, and each sub-light-emitting unit radiates a beam of illumination light waves; The illumination light waves radiated by each sub-light-emitting unit are regulated by the first shaping component and then incident on the polarization beam splitter prism (13); the illumination light waves are reflected by the beam splitting surface of the polarization beam splitter prism (13) and then incident on the image source (12); the image source (12) loads image information on the incident illumination light waves to obtain display light waves; after the display light waves are reflected back to the polarization beam splitter prism (13) by the image source (12), they are directly transmitted from the beam splitting surface to the second shaping component, and then, after being regulated by the second shaping component, they are projected from an off-axis position to the optical combiner (14); the optical combiner (14) focuses the display light waves in the form of a two-dimensionally distributed viewpoint array onto the pupil plane of the human eye, and the range of the viewpoint array formed by the display light waves is larger than the range of movement of the pupil of the human eye; When near-eye display is required, the eye tracking camera (15) is used to obtain the pupil center position in real time; the processing module determines the sub-light-emitting unit that needs to be lit according to the pupil center position, and the lit sub-light-emitting unit forms a corresponding viewpoint in the pupil of the human eye, so that the image source (12) is imaged on the retina; The processing module determines the sub-light-emitting unit that needs to be lit according to the center position of the pupil: The two-dimensional array of sub-light emitting units and the two-dimensional viewpoint array of display light waves are both constructed with the center of the array as the origin to construct a rectangular coordinate system. It is assumed that the position coordinate of the pupil center is ( , ), then the theoretical position coordinates of the sub-light-emitting unit that needs to be lit are ( , ),in, is the lateral magnification of the entire optical system, is the longitudinal magnification of the entire optical system; will be compared with the theoretical position coordinates ( , ) The sub-light-emitting unit that is closest in position is used as the sub-light-emitting unit that is finally lit; The incident angles of the illumination light waves radiated by the sub-light-emitting units at different positions on the illumination source (11) on the image source (12) are different; for the sub-light-emitting units at the edge positions of the illumination source (11), the incident angles of the illumination light waves radiated by them on the image source (12) are the largest, and the maximum incident angle of the collimated illumination light waves incident on the image source (12) is not greater than 12 degrees; Each pupil center position corresponds to a viewpoint, and the spot size of each viewpoint is less than 0.1mm; The optical combiner (14) includes a diffraction grating (141) and a base layer (142) for supporting the diffraction grating (141); The diffraction grating (141) is a reflective holographic grating or a relief grating; the diffraction grating (141) diffracts the illumination light waves radiated by different sub-light-emitting units on the illumination source (11) projected onto its surface to a viewpoint array located on the pupil plane.

2. The multi-viewpoint retinal projection augmented reality near-eye display optical system according to claim 1, characterized in that: The first shaping component comprises a first collimating lens (21) and a first reflecting mirror (31) coaxial with the illumination source (11); The illumination light waves radiated by the sub-light-emitting units are focused by the first collimating lens (21) to obtain collimated illumination light waves, and the collimated illumination light waves are then incident on the polarization beam splitting prism (13) via the first reflector (31).

3. The multi-viewpoint retinal projection augmented reality near-eye display optical system according to claim 1, characterized in that: The second shaping component comprises a second collimating lens (22), a second reflector (32), and a third reflector (33), wherein the third reflector (33) is located at an off-axis position of the optical combiner (14); at the same time, the image source (12), the polarization beam splitter prism (13), the second collimating lens (22), and the second reflector (32) are located in a coaxial optical path and are all located at an off-axis position of the third reflector (33); the vertical distance between the third reflector (33) and the second reflector (32) should ensure that the third reflector (33) does not block the display light wave; The display light wave is transmitted from the splitting surface of the polarization splitting prism (13) to the second collimating lens (22) for collimation, thereby obtaining a collimated display light wave; the collimated display light wave is reflected twice in sequence by the second reflector (32) and the third reflector (33) to the optical combiner (14).

4. The multi-viewpoint retinal projection augmented reality near-eye display optical system according to claim 1, characterized in that: The illumination light waves radiated by each sub-light-emitting unit of the illumination source (11) completely fill the effective use area of ​​the image source (12), and the effective use area of ​​the image source (12) is rectangular.

5. The multi-viewpoint retinal projection augmented reality near-eye display optical system according to claim 1, characterized in that: Each sub-light-emitting unit of the illumination source (11) can be independently controlled, and each sub-light-emitting unit of the illumination source (11) corresponds to a viewpoint that converges on the pupil plane.

6. The multi-viewpoint retinal projection augmented reality near-eye display optical system according to claim 1, characterized in that: The lighting source (11) is an LCD panel, a Micro-LED panel or a Micro-OLED panel; The illumination light waves radiated by each sub-light-emitting unit of the illumination source (11) are monochromatic illumination light waves or polychromatic illumination light waves, and the illumination light waves are all perpendicular to the plane where the image source (12) is located.

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