Single-display binocular diopter-adjustable near-eye display system

Abstract

Disclosed in the present invention is a single-display binocular diopter-adjustable near-eye display system, comprising a display, a beam splitter prism, a first imaging display unit, and a second imaging display unit. The display is used for emitting imaging light and moving relative to the beam splitter prism to achieve diopter adjustment. The beam splitter prism is for splitting the imaging light emitted from the display into two paths to be incident on the imaging display units in a one-to-one correspondence manner. The imaging display units have one-to-one correspondence to human eyes, and each comprise a first imaging lens unit, a planar reflector, and a curved mirror, wherein the planar reflector is inclined relative to an optical axis of the first imaging lens unit, the mirror surface of the curved mirror away from the human eyes is coated with a light splitting film, and the mirror surface of the curved mirror close to the human eyes is coated with an anti-reflection film. According to the system, binocular viewing is achieved using a single display, helping to reduce the costs, achieve miniaturization and light weight, and achieve a larger eyebox range and field of view angle; in addition, the imaging quality is excellent, and the requirements of people with different vision can be met.

Description

A single-display binocular diopter-adjustable near-eye display system Technical Field

[0001] The present invention belongs to the technical field of near-eye display, and in particular relates to a single-display binocular diopter-adjustable near-eye display system. Background Art

[0002] With the emergence of virtual reality (VR) and augmented reality (AR), the market for near-eye display devices based on VR or AR modes has also seen rapid growth. Near-eye display devices are optical systems that project images directly into the viewer's eyes. They are currently widely used in fields such as film viewing, gaming, education, industry, and healthcare, and the corresponding technologies and product performance have continued to improve. However, existing near-eye display optical systems still suffer from heavy weight, large size, a small field of view, and low resolution. Furthermore, the cost of individual modules is high during mass production, making it difficult to achieve a larger field of view (FOV) and eyebox (EYEBOX) with current display specifications. Therefore, to overcome these issues, a single-display binocular diopter-adjustable near-eye display system with a large field of view, high resolution, and ultra-thin design is proposed. Summary of the Invention

[0003] The purpose of the present invention is to address the above-mentioned problems and propose a single-display binocular diopter-adjustable near-eye display system, which can achieve binocular viewing using a single display, helps to reduce costs, achieve small size and light weight, and a larger eye movement range and field of view. It also has excellent imaging quality and can adapt to the needs of people with different vision.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] The present invention proposes a single-display binocular diopter-adjustable near-eye display system, comprising a display, a diopter prism, a first imaging display unit, and a second imaging display unit, wherein:

[0006] A display, configured to emit imaging light and move relative to the diopter prism to achieve diopter adjustment;

[0007] A beam splitter prism is used to split the imaging light emitted by the display into two paths, and the two imaging light paths are incident on the imaging display unit in a one-to-one correspondence;

[0008] Each imaging display unit corresponds to a human eye and includes a first imaging lens unit, a plane reflector, and a curved mirror. The first imaging lens unit includes at least one lens. The plane reflector is tilted relative to the optical axis of the first imaging lens unit. The surface of the curved mirror away from the human eye is coated with a dichroic coating, and the surface close to the human eye is coated with an antireflection coating. The curved mirror meets the following conditions:

[0009] 10mm<|f1|<30mm, 1.2mm <CT1<2mm,42mm<L<50mm,1.8<L / D<2.1;

[0010] Where f1 is the focal length of the curved mirror, CT1 is the thickness of the curved mirror, L is the length of the curved mirror, that is, the left-right distance of the curved mirror when worn by the human body, and D is the width of the curved mirror, that is, the up-down distance of the curved mirror when worn by the human body;

[0011] The imaging light received by the imaging display unit passes through the first imaging lens unit, is reflected by the plane reflector to the curved mirror, and then reflected by the curved mirror to the human eye. At the same time, external light enters the human eye through the curved mirror.

[0012] Preferably, the imaging display unit also includes a plane mirror imaging unit, which is tilted relative to the first optical axis and the tilt angle is 30°~60°. The first optical axis is a line connecting the center of the human eye and the center of the curved mirror. The plane mirror imaging unit includes a plane mirror and a semi-transparent and semi-reflective film or a first polarization unit is provided on the side close to the curved mirror, and an anti-reflection film is provided on the side away from the curved mirror. The first polarization unit is at least one of a polarizing film, a polarizing reflective film, a phase delay film and an anti-reflection film.

[0013] Preferably, the first polarizing unit includes a polarizing reflective film, a phase delay film and a polarizing film which are attached in sequence.

[0014] Preferably, the first imaging lens unit satisfies -15mm≤f0≤-6mm, where f0 is the focal length of the first imaging lens unit.

[0015] Preferably, the first imaging lens unit includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence along the light propagation direction, the first lens is a glass spherical lens with negative optical power, the second lens is a glass spherical lens with positive optical power, the third lens is a plastic aspherical lens with negative optical power, and the fourth lens is a glass spherical lens with negative optical power, and the following conditions are met:

[0016] 10mm<|f2|<25mm, 1mm <CT2<3mm,1<CT2 / ET2<1.5;

[0017] 7mm<|f3|<15mm, 0.5mm <CT3<3mm,0.6<CT3 / ET3<1;

[0018] 10mm<|f4|<20mm, 0.5mm <CT4<3mm,H / h<3;

[0019] 10mm<|f5|<20mm, 1mm <CT5<3mm,0.7<CT5 / ET5<1.5;

[0020] Wherein, f2 is the focal length of the first lens, CT2 is the center thickness of the first lens, ET2 is the edge thickness of the first lens, f3 is the focal length of the second lens, CT3 is the center thickness of the second lens, ET3 is the edge thickness of the second lens, f4 is the focal length of the third lens, CT4 is the center thickness of the third lens, H is the maximum thickness of the third lens, H=CT4, h is the minimum thickness of the third lens, f5 is the focal length of the fourth lens, CT5 is the center thickness of the fourth lens, and ET5 is the edge thickness of the fourth lens.

[0021] Preferably, the first imaging lens unit satisfies 10 mm ≤ f0 ≤ 20 mm, where f0 is the focal length of the first imaging lens unit.

[0022] Preferably, the first imaging lens unit includes a fifth lens, a sixth lens, and a seventh lens sequentially arranged along the light propagation direction, the fifth lens is a plastic aspheric lens with positive optical power, the sixth lens is a plastic aspheric lens with negative optical power, and the seventh lens is a plastic aspheric lens with positive optical power, and the following conditions are met:

[0023] 12mm<|f6|<15mm, 4mm <CT6<5.5mm,1.8<CT6 / ET6<4;

[0024] 12mm<|f7|<15mm, 0.7mm <CT7<1.5mm,2<ET7 / CT7<5;

[0025] 12mm<|f8|<15mm, 4.5mm <CT8<6.2mm,1<CT8 / ET8<3;

[0026] Among them, f6 is the focal length of the fifth lens, CT6 is the center thickness of the fifth lens, ET6 is the edge thickness of the fifth lens, f7 is the focal length of the sixth lens, CT7 is the center thickness of the sixth lens, ET7 is the edge thickness of the sixth lens, f8 is the focal length of the seventh lens, CT8 is the center thickness of the seventh lens, and ET8 is the edge thickness of the seventh lens.

[0027] Preferably, the single-display binocular refractive power adjustable near-eye display system also includes a second imaging lens unit, the second imaging lens unit includes at least one lens, and the focal length of the second imaging lens unit is -130mm≤f≤-100mm, and the imaging light emitted by the display passes through the second imaging lens unit and enters the dichroic prism.

[0028] Preferably, the mirror surface of each lens on the first imaging lens unit is coated with an anti-reflection film and the optical axis is arranged horizontally.

[0029] Preferably, the mirror surface of the curved mirror is a spherical surface, an aspherical surface or a free-form surface, and the transmittance-reflection ratio of the beam splitter film on the curved mirror is 1:4 to 1:1, and the reflectivity of the anti-reflection film on the curved mirror is <1%.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] This near-eye display system uses a single display to achieve binocular viewing, reducing costs and making the system compact and lightweight. Under the joint action of the first imaging lens unit and the curved mirror, the virtual display optical path achieves a larger eye movement range and field of view, with excellent imaging quality and low distortion. In addition, by adjusting the distance between the display and the diopter prism, the diopter can be changed from 0D to -6D to meet the needs of people with different vision, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a schematic structural diagram of a single-display binocular diopter-adjustable near-eye display system according to Embodiment 1 of the present invention;

[0033] FIG2 is a top view of a single-display binocular diopter-adjustable near-eye display system according to Embodiment 1 of the present invention;

[0034] FIG3 is a left side view of the single-display binocular diopter-adjustable near-eye display system according to Embodiment 1 of the present invention;

[0035] FIG4 is a cross-sectional view AA of a single-display binocular diopter-adjustable near-eye display system according to embodiment 1 of the present invention;

[0036] FIG5 is an MTF diagram of Example 1 of the present invention;

[0037] FIG6 is a distortion diagram of Example 1 of the present invention;

[0038] FIG7 is a front view of a single-display binocular diopter-adjustable near-eye display system according to Embodiment 2 of the present invention;

[0039] FIG8 is a schematic diagram of the optical path structure of the first imaging display unit or the second imaging display unit according to embodiment 2 of the present invention;

[0040] FIG9 is an MTF diagram of Example 2 of the present invention.

[0041] Explanation of the accompanying drawings: 1. Display; 2. Beam-splitting prism; 3. First imaging lens unit; 4. Plane reflector; 5. Plane mirror imaging unit; 6. Curved mirror; 7. Human eye; 8. Second imaging lens unit; 31. First lens; 32. Second lens; 33. Third lens; 34. Fourth lens; 35. Fifth lens; 36. Sixth lens; 37. Seventh lens. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] It should be noted that when a component is referred to as being "connected" to another component, it may be directly connected to the other component or there may be an intermediate component. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art in the art of this application. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Example

[0044] As shown in FIG1-6, a single-display binocular diopter-adjustable near-eye display system includes a display 1, a beam splitter prism 2, a first imaging display unit, and a second imaging display unit, wherein:

[0045] Display 1, used to emit imaging light and move relative to the diopter prism 2 to achieve diopter adjustment;

[0046] The beam splitter prism 2 is used to split the imaging light emitted by the display 1 into two paths, and the two paths of imaging light are incident on the imaging display unit in a one-to-one correspondence;

[0047] Each imaging display unit corresponds to a human eye and includes a first imaging lens unit 3, a plane reflector 4, and a curved mirror 6. The first imaging lens unit 3 includes at least one lens. The plane reflector 4 is tilted relative to the optical axis of the first imaging lens unit 3. The surface of the curved mirror 6 away from the human eye is coated with a dichroic coating, and the surface close to the human eye is coated with an antireflection coating. The curved mirror 6 meets the following conditions:

[0048] 10mm<|f1|<30mm, 1.2mm <CT1<2mm,42mm<L<50mm,1.8<L / D<2.1;

[0049] Wherein, f1 is the focal length of the curved mirror 6, CT1 is the thickness of the curved mirror 6, L is the length of the curved mirror 6, i.e., the left-right distance of the curved mirror 6 when worn by a human body, and D is the width of the curved mirror 6, i.e., the up-down distance of the curved mirror 6 when worn by a human body;

[0050] The imaging light received by the imaging display unit passes through the first imaging lens unit 3, is reflected by the plane reflector 4 to the curved mirror 6, and then reflected by the curved mirror 6 to the human eye. At the same time, the external light enters the human eye through the curved mirror 6.

[0051] Among them, the display 1 (microdisplay) includes but is not limited to one of an LCoS display, an OLED-on-silicon display, a micro-LED display, and a DLP display. Each surface of the beam splitter prism 2 is a plane and does not provide optical power for the optical system. The beam splitter prism 2 includes a rectangular block composed of four multi-prisms (such as two triangular prisms and two quadrangular prisms), and is designed with a symmetric structure. Each inclined surface is coated with a beam splitting film, which plays the role of transmitting and reflecting light. The material is high-refractive-index glass, satisfying 1.75 < nd < 1.9, where nd is the refractive index. The curved mirror 6 plays the role of reflecting and transmitting light, and each mirror surface can be a spherical surface, an aspherical surface, or a free-form surface. The focal length value of the curved mirror 6 within the above range can satisfy the required virtual image distance, and by reasonably setting the thickness and aspect ratio of the curved mirror 6, thinning and better wearing immersion can be achieved. The surfaces of the plane mirror 4 are all planes and do not provide optical power for the optical system, and play the role of reflecting light. For example, a metal reflection film or a dielectric reflection film is coated on one side close to the first imaging lens unit 3.

[0052] The entire system has a symmetric distribution structure, including exactly the same first virtual display optical path and second virtual display optical path, as well as exactly the same third perspective display optical path and fourth perspective display optical path. The two virtual display optical paths share a set of the display 1 and the beam splitter prism 2. Using one display 1 can achieve binocular viewing, reduce the number of displays 1 to achieve cost reduction and miniaturization and light weight, and under the combined action of the first imaging lens unit 3 and the curved mirror 6, the virtual display optical path can achieve a larger eye movement range and field of view.

[0053] In one embodiment, the imaging display unit further includes a plane mirror imaging unit 5. The plane mirror imaging unit 5 is inclined relative to the first optical axis at an inclination angle of 30° to 60°. The first optical axis is the connection line between the center corresponding to the human eye and the center of the curved mirror 6. The plane mirror imaging unit 5 includes a plane mirror, and a half-transmissive and half-reflective film or a first polarization unit is provided on one side close to the curved mirror 6, and an anti-reflection film is provided on the side far from the curved mirror 6. The first polarization unit is at least one of a polarization film, a polarization reflection film, a phase retardation film, and an anti-reflection film.

[0054] Among them, the surfaces of the plane mirror are all planes and do not provide optical power for the optical system, and play the role of beam splitting. A half-transmissive and half-reflective film or a polarization property film (first polarization unit) is coated on one side of the plane mirror close to the curved mirror 6.

[0055] In this embodiment, the imaging display unit of the virtual display optical path receives imaging light, which is then reflected by plane mirror 4 onto plane mirror imaging unit 5 through first imaging lens unit 3. Plane mirror imaging unit 5 then reflects the light onto curved mirror 6. Curved mirror 6 then reflects the light, which then passes through plane mirror imaging unit 5 and enters the human eye. Simultaneously, external light sequentially passes through curved mirror 6 and plane mirror imaging unit 5 and enters the human eye. In the perspective display optical path, external light also sequentially passes through corresponding curved mirror 6 and plane mirror imaging unit 5 and enters the human eye.

[0056] In one embodiment, the first polarizing unit includes a polarizing reflective film, a phase delay film, and a polarizing film attached in sequence, and the specific combination can be adjusted according to actual needs.

[0057] In one embodiment, the first imaging lens unit 3 satisfies -15mm≤f0≤-6mm, where f0 is the focal length of the first imaging lens unit 3. This can increase the system FOV and reduce optical aberrations, especially distortion, at a large FOV.

[0058] In one embodiment, the first imaging lens unit 3 includes a first lens 31, a second lens 32, a third lens 33, and a fourth lens 34, which are sequentially arranged along the light propagation direction. The first lens 31 is a glass spherical lens with negative optical power, the second lens 32 is a glass spherical lens with positive optical power, the third lens 33 is a plastic aspherical lens with negative optical power, and the fourth lens 34 is a glass spherical lens with negative optical power. The following conditions are met:

[0059] 10mm<|f2|<25mm, 1mm <CT2<3mm,1<CT2 / ET2<1.5;

[0060] 7mm<|f3|<15mm, 0.5mm <CT3<3mm,0.6<CT3 / ET3<1;

[0061] 10mm<|f4|<20mm, 0.5mm <CT4<3mm,H / h<3;

[0062] 10mm<|f5|<20mm, 1mm <CT5<3mm,0.7<CT5 / ET5<1.5;

[0063] Wherein, f2 is the focal length of the first lens 31, CT2 is the center thickness of the first lens 31, ET2 is the edge thickness of the first lens 31, f3 is the focal length of the second lens 32, CT3 is the center thickness of the second lens 32, ET3 is the edge thickness of the second lens 32, f4 is the focal length of the third lens 33, CT4 is the center thickness of the third lens 33, H is the maximum thickness of the third lens 33, H=CT4, h is the minimum thickness of the third lens 33, f5 is the focal length of the fourth lens 34, CT5 is the center thickness of the fourth lens 34, and ET5 is the edge thickness of the fourth lens 34.

[0064] Among them, by reasonably setting the focal length and thickness of each lens, the system FOV can be increased, and the optical aberration under large FOV, especially distortion, can be reduced, greatly improving the imaging quality.

[0065] In one embodiment, the single-display binocular diopter-adjustable near-eye display system further includes a second imaging lens unit 8 , which includes at least one lens and has a focal length of -130 mm ≤ f ≤ -100 mm. Imaging light emitted by the display 1 passes through the second imaging lens unit 8 and enters the beam splitter prism 2 . The CRA angle of the emitted light can be adjusted by the second imaging lens unit 8 .

[0066] In one embodiment, the mirror surfaces of each lens in the first imaging lens unit 3 are coated with an antireflection coating, and the optical axis is set horizontally. The antireflection coating increases light energy utilization and reduces potential stray light. The horizontal direction is the left-right direction when the wearer is wearing the device.

[0067] In one embodiment, the surface of the curved mirror 6 is spherical, aspherical, or free-form, and the transmittance-reflection ratio of the beam splitter coating on the curved mirror 6 is 1:4 to 1:1, and the reflectivity of the anti-reflection coating on the curved mirror 6 is less than 1%. Each surface of the curved mirror 6 can be spherical, aspherical, or free-form. For example, to improve the display performance of the optical system and reduce the difficulty of system processing, both surfaces can be designed as aspherical.

[0068] The working principle of the single-display binocular diopter-adjustable near-eye display system of this embodiment is as follows:

[0069] The first and second virtual display optical paths are identical, corresponding to the left and right eyes, respectively. The imaging process of the virtual display optical paths is as follows: Display 1 emits imaging light, which is split into two paths by a beam splitter prism 2 and incident on the imaging display unit in a one-to-one correspondence. The imaging light received by the imaging display unit passes through the first imaging lens unit 3, is reflected by a plane reflector 4 to a plane mirror imaging unit 5, and then from the plane mirror imaging unit 5 to a curved mirror 6. Curved mirror 6 then reflects the light through the plane mirror imaging unit 5 to the human eye. Specifically, a portion of the imaging light is split and deflected by the beam splitter prism 2 before entering the first imaging lens unit 3. Each lens surface of the first imaging lens unit 3 can be coated with an anti-reflection coating to increase light energy utilization and reduce potential stray light. After reaching the plane reflector 4, the light is deflected and propagates downward, passing through the plane mirror imaging unit 5. A portion of the light is then reflected by the curved mirror 6, which then reflects it back to the plane mirror imaging unit 5, passing through it and ultimately entering the human eye.

[0070] The third perspective display optical path and the fourth perspective display optical path are the same, and correspond to the left and right eyes of the human body respectively. The imaging process of the perspective display optical path is as follows: the external light first passes through the outer surface of the corresponding curved mirror 6 (that is, the mirror surface away from the plane mirror imaging unit 5), and the reflected light is lost at the inner surface (that is, the mirror surface close to the plane mirror imaging unit 5) and the transmitted light continues to propagate into the plane mirror imaging unit 5 and passes through, and finally enters the human eye.

[0071] The following is a detailed description through specific embodiments to facilitate understanding.

[0072] In this embodiment, the first virtual display optical path is formed by the display 1, the dichroic prism 2, and the first imaging display unit. The second virtual display optical path is formed by the display 1, the dichroic prism 2, and the second imaging display unit. The two virtual display optical paths share a set of display 1 and dichroic prism 2. The third perspective display optical path is formed by the plane mirror imaging unit 5 and the curved mirror 6 of the first imaging display unit. The fourth perspective display optical path is formed by the plane mirror imaging unit 5 and the curved mirror 6 of the second imaging display unit. A semi-transparent and semi-reflective film is provided on the side of the plane mirror of the plane mirror imaging unit 5 near the curved mirror 6. The mirror surface of the curved mirror 6 closest to the human eye is convex, and the mirror surface away from the human eye is concave. The aperture is the position of the human eye. By adjusting the distance between the display 1 and the dichroic prism 2, the diopter can be changed from 0D to -6D to meet the needs of people with different vision.

[0073] The parameters of each optical element are shown in Table 1 below:

[0074] Table 1

[0075] Surface No. Surface type Curvature radius (mm) Thickness (mm) Refractive index Abbe number Surface properties Aperture Spherical infinite \\\Refractive plane mirror-01 Spherical infinite 11.5555.90Refractive plane mirror-02 Spherical infinite 16.5\\Refractive curved mirror 6-02 Aspherical -38.1-16.5\\Reflective plane mirror-02 Spherical infinite 17\\Reflective plane reflective mirror 4-02 Spherical infinite -8\\Reflective fourth lens 34-01 Spherical -13.4-3.031.931.32Refractive fourth lens 34-02 Spherical 697.9-1.41Refractive third lens 33-01 Aspherical -14.55-2 .61.5555.90 Refractive third lens 33-02 Aspherical 22.4-0.2\\ Refractive second lens 32-01 Spherical 26.8-11.9517.9 Refractive second lens 32-02 Spherical -12.6-1.5 Refractive first lens 31-01 Spherical -34.8-3.31.931.32 Refractive first lens 31-02 Spherical 14.4-4.5 Refractive Beamsplitter Prism-01 Spherical Infinity -6.51.8423.78 Refractive Beamsplitter Prism-02 Spherical Infinity 6.51.8423.78 Reflective Beamsplitter Prism-03 Spherical Infinity 2 Refractive Display Spherical Infinity\\Refractive

[0076] In Table 1, beam splitter prism-01 represents the exit surface of the beam splitter prism, beam splitter prism-02 represents the inclined surface where the beam splitter film of the beam splitter prism is located, beam splitter prism-03 represents the incident surface of the beam splitter prism, plane mirror-01 represents the mirror surface of the plane mirror close to the human eye, plane mirror-02 represents the mirror surface of the plane mirror farthest from the human eye, fourth lens 34-01 represents the exit surface of the fourth lens 34, fourth lens 34-02 represents the incident surface of the fourth lens 34, third lens 33-01 represents the exit surface of the third lens 33 The third lens 33-02 represents the incident surface of the third lens 33, the second lens 32-01 represents the exit surface of the second lens 32, the second lens 32-02 represents the incident surface of the second lens 32, the first lens 31-01 represents the exit surface of the first lens 31, the first lens 31-02 represents the incident surface of the first lens 31, the plane mirror 4-02 represents the mirror surface on the plane mirror close to the first imaging lens unit 3, and the curved mirror 6-02 represents the mirror surface on the curved mirror 6 close to the human eye.

[0077] The aspheric surface shape satisfies the following equation:

[0078]

[0079] Where z is the sag, c is the inverse of the radius of curvature, r is the radial distance of a point on the mirror surface, k is the quadratic surface constant, and A, B, C, D, E, F, G, H, and I are the coefficients of higher-order terms.

[0080] The aspheric coefficients are shown in Table 2:

[0081] Table 2

[0082] Curved Mirror 6-02 Third Lens 33-01 Third Lens 33-02 Conic Constant (k) 0.2195 3.014 -6 0.094 24th Order Coefficient (A) 1.5828e-06 0.000 3326 0.000 13 4956th Order Coefficient (B) -7.7566e-09 -2.0619e-05 2.07e-05 8th Order Coefficient (C) 5.5688e-11 4.0317e-06 -4.1115e-06 10th Order Coefficient (D) -1.6578e-13 -3.6408e-07 3.4808e-07 12th Order Coefficient (E) 1.8095e-16 2.0069e-08 -1.7210e-08 14th Order Coefficient (F)0-6.8986e-105.3212e-1016th Order Coefficient (G)01.4663e-11-9.9728e-1218th Order Coefficient (H)0-1.7631e-131.0287e-1320th Order Coefficient (I)09.2036e-16-4.4346e-16

[0083] According to the above data, as shown in Figures 5 and 6, the single-display binocular diopter-adjustable near-eye display system of this embodiment has an MTF greater than 0.4 at 30lp / mm, a distortion less than 1%, excellent imaging quality, a field of view angle FOV of 45°~50°, and an eye movement range EYEBOX of 10*6~12*8. Example

[0084] As shown in Figures 7-9, a single-display binocular diopter-adjustable near-eye display system includes a display 1, a beam splitter prism 2, a first imaging display unit, and a second imaging display unit, wherein:

[0085] Display 1, used to emit imaging light and move relative to the diopter prism 2 to achieve diopter adjustment;

[0086] The beam splitter prism 2 is used to split the imaging light emitted by the display 1 into two paths, and the two paths of imaging light are incident on the imaging display unit in a one-to-one correspondence;

[0087] Each imaging display unit, corresponding to the human eye 7 one by one, includes a first imaging lens unit 3, a planar mirror 4, and a curved mirror 6. The first imaging lens unit 3 includes at least one lens. The planar mirror 4 is inclined with respect to the optical axis of the first imaging lens unit 3. A beam-splitting film is coated on the mirror surface of the curved mirror 6 far from the human eye 7, and an anti-reflection film is coated on the mirror surface close to the human eye 7. And the curved mirror 6 satisfies the following conditions:

[0088] 10mm < |f1| < 30mm, 1.2mm < CT1 < 2mm, 42mm < L < 50mm, 1.8 < L / D < 2.1;

[0089] Where, f1 is the focal length of the curved mirror 6, CT1 is the thickness of the curved mirror 6, L is the length of the curved mirror 6, that is, the left-right direction distance when worn by the human body, and D is the width of the curved mirror 6, that is, the up-down direction distance when worn by the human body;

[0090] After the imaging light rays correspondingly received by the imaging display unit pass through the first imaging lens unit 3, they are reflected by the planar mirror 4 to the curved mirror 6, and then reflected by the curved mirror 6 to the human eye 7. At the same time, the external light rays pass through the curved mirror 6 and enter the human eye 7.

[0091] Among them, the display 1 (micro display) includes but is not limited to one of an LCoS display, a silicon-based OLED display, a micro-LED display, and a DLP display. Each surface of the beam-splitting prism 2 is a plane and does not provide optical power for the optical system. The beam-splitting prism 2 includes a rectangular block composed of four multi-prisms (such as two triangular prisms and two quadrangular prisms), and is designed with a symmetric structure. Each inclined surface is coated with a beam-splitting film, which plays the role of transmitting and reflecting light rays. The material is high-refractive-index glass, satisfying 1.75 < nd < 1.9, where nd is the refractive index. The curved mirror 6 plays the role of reflecting and transmitting light rays. Each mirror surface can be a spherical surface, an aspherical surface, or a free-form surface. The focal length value of the curved mirror 6 within the above range can meet the required virtual image distance, and by reasonably setting the thickness and aspect ratio of the curved mirror 6, lightweight and better wearing immersion can be achieved. The surfaces of the planar mirror 4 are all planes and do not provide optical power for the optical system, and play the role of reflecting light rays. For example, a metal reflection film or a dielectric reflection film is coated on the side close to the first imaging lens unit 3.

[0092] The entire system is a symmetric distribution structure, including completely identical first virtual display optical paths and second virtual display optical paths, as well as completely identical third perspective display optical paths and fourth perspective display optical paths. The two virtual display optical paths share a set of display 1 and beam-splitting prism 2. Using one display 1 can achieve binocular viewing, reduce the number of displays 1 to achieve cost reduction and miniaturization and lightweight, and under the combined action of the first imaging lens unit 3 and the curved mirror 6, the virtual display optical path can achieve a larger eye movement range and field of view.

[0093] In one embodiment, the first imaging lens unit 3 satisfies 10 mm ≤ f0 ≤ 20 mm, where f0 is the focal length of the first imaging lens unit 3. This can increase the system FOV and reduce optical aberrations, especially distortion, at a large FOV.

[0094] In one embodiment, the first imaging lens unit 3 includes a fifth lens 35, a sixth lens 36, and a seventh lens 37, which are sequentially arranged along the light propagation direction. The fifth lens 35 is a plastic aspheric lens with positive refractive power, the sixth lens 36 is a plastic aspheric lens with negative refractive power, and the seventh lens 37 is a plastic aspheric lens with positive refractive power. The following conditions are met:

[0095] 12mm<|f6|<15mm, 4mm <CT6<5.5mm,1.8<CT6 / ET6<4;

[0096] 12mm<|f7|<15mm, 0.7mm <CT7<1.5mm,2<ET7 / CT7<5;

[0097] 12mm<|f8|<15mm, 4.5mm <CT8<6.2mm,1<CT8 / ET8<3;

[0098] Among them, f6 is the focal length of the fifth lens 35, CT6 is the center thickness of the fifth lens 35, ET6 is the edge thickness of the fifth lens 35, f7 is the focal length of the sixth lens 36, CT7 is the center thickness of the sixth lens 36, ET7 is the edge thickness of the sixth lens 36, f8 is the focal length of the seventh lens 37, CT8 is the center thickness of the seventh lens 37, and ET8 is the edge thickness of the seventh lens 37.

[0099] Among them, by reasonably setting the focal length and thickness of each lens, the system FOV can be increased, and the optical aberration under large FOV, especially distortion, can be reduced, greatly improving the imaging quality.

[0100] In one embodiment, the single-display binocular diopter-adjustable near-eye display system further includes a second imaging lens unit 8 , which includes at least one lens and has a focal length of -130 mm ≤ f ≤ -100 mm. Imaging light emitted by the display 1 passes through the second imaging lens unit 8 and enters the beam splitter prism 2 . The CRA angle of the emitted light can be adjusted by the second imaging lens unit 8 .

[0101] In one embodiment, the mirror surfaces of each lens in the first imaging lens unit 3 are coated with an antireflection coating, and the optical axis is set horizontally. The antireflection coating increases light energy utilization and reduces potential stray light. The horizontal direction is the left-right direction when the wearer is wearing the device.

[0102] In one embodiment, the surface of the curved mirror 6 is spherical, aspherical, or free-form, and the transmittance-reflection ratio of the beam splitter coating on the curved mirror 6 is 1:4 to 1:1, and the reflectivity of the anti-reflection coating on the curved mirror 6 is less than 1%. Each surface of the curved mirror 6 can be spherical, aspherical, or free-form. For example, to improve the display performance of the optical system and reduce the difficulty of system processing, both surfaces can be designed as aspherical.

[0103] The working principle of the single-display binocular diopter-adjustable near-eye display system of this embodiment is as follows:

[0104] The first and second virtual display optical paths are identical, corresponding to the left and right eyes, respectively. The imaging process of the virtual display optical paths is as follows: Display 1 emits imaging light, which is split into two paths by a beam splitter prism 2 and incident on the imaging display unit in a one-to-one correspondence. The imaging light received by the imaging display unit passes through the first imaging lens unit 3, where it is reflected by a plane mirror 4 onto a curved mirror 6. The curved mirror 6 then reflects the light back to the eye 7. Specifically, a portion of the imaging light is split and deflected by the beam splitter prism 2 before entering the first imaging lens unit 3. Each lens surface of the first imaging lens unit 3 can be coated with an anti-reflection coating to increase light energy utilization and reduce potential stray light. After reaching the plane mirror 4, the light is deflected and propagates downward, reflected onto the curved mirror 6, and then reflected back to the eye 7 by the curved mirror 6.

[0105] The third perspective display optical path and the fourth perspective display optical path are the same, and also correspond to the left and right eyes of the human body, respectively. The imaging process of the perspective display optical path is as follows: the external light first passes through the outer surface of the corresponding curved mirror 6 (i.e., the mirror surface away from the human eye 7), and the light is lost at the reflection on the inner surface (i.e., the mirror surface close to the human eye 7), and the transmitted light continues to propagate into the human eye 7.

[0106] The following is a detailed description through specific embodiments to facilitate understanding.

[0107] In this embodiment, the first virtual display optical path is formed by the display 1, the beam splitter prism 2, and the first imaging display unit. The second virtual display optical path is formed by the display 1, the beam splitter prism 2, and the second imaging display unit. The two virtual display optical paths share a set of the display 1 and the beam splitter prism 2. The third perspective display optical path is formed by the curved mirror 6 of the first imaging display unit, and the fourth perspective display optical path is formed by the curved mirror 6 of the second imaging display unit. The second imaging lens unit 8 is located between the display 1 and the beam splitter prism 2 and is a shared structure for the two virtual display optical paths. It includes an eighth lens. The incident surface of the eighth lens is concave, and the exit surface is convex, and 1.5 < CT9 < 3 and 1.5 < CT9 / ET9 < 3 are satisfied, where CT9 is the central thickness of the eighth lens and ET9 is the edge thickness of the eighth lens. The mirror surface of the curved mirror 6 close to the human eye 7 is convex, and the mirror surface far from the human eye 7 is concave. The aperture stop is at the position of the human eye 7. By adjusting the distance between the display 1 and the beam splitter prism 2, a change in diopter from 0D to -6D is achieved to meet the needs of people with different visual acuities.

[0108] In this embodiment, the plane mirror imaging unit 5 is cancelled compared with Embodiment 1. On the one hand, the stray light problem caused by the lower part of the human eye can be completely eliminated (in Embodiment 1, external light enters the human eye under the reflection of the plane mirror imaging unit 5 to generate stray light). On the other hand, the exit pupil light efficiency can be improved, and it is beneficial to further reduce costs while achieving thinness and lightness. Each mirror surface of the curved mirror 6 adopts a free-form surface and has a larger FOV. <000,0250>

[0109] The parameters of each optical element are shown in Table 3 below:

[0110] Table 3 [[ID=ll]]

[0111] Surface Serial Number Surface Type Curvature Radius (mm) Thickness (mm) Refractive Index Abbe Number Surface Attribute Aperture Stop Spherical Infinite \\\ Refractive Curved Mirror 6-02 XY Polynomial 77.5 -52 \\\ Reflective Plane Reflecting Mirror 4-02 Spherical Infinite 12 \\\ Reflective Seventh Lens 37-01 Aspherical 11,5 45.9 1.535 55.9 Refractive Seventh Lens 37-02 Aspherical -17.1 0.6 Refractive Sixth Lens 36-01 Aspherical -21.2 11.58 30 Refractive Sixth Lens 36-02 Aspherical 13.48 0.3 \\\ Refractive Fifth Lens 35-01 Aspherical 12.74 5 1.535 55.9 Refractive Fifth Lens 35-02 Aspherical -15.4 0.25 Refractive Beam Splitter Prism -01 Spherical Infinite 7.5 1.526 4 Refractive Beam Splitter Prism -02 Spherical Infinite -7.5 1.526 4 Reflective Beam Splitter Prism -03 Spherical Infinite -0.25 Refractive Second Imaging Lens Unit 8-01 Aspherical -21 -2.6 1.55 7.5 Refractive Second Imaging Lens Unit 8-02 Aspherical -30.7 -3.5 Refractive Display Spherical Infinite \\\ Refractive

[0112] The aspheric surface shape satisfies the following equation:

[0113]

[0114] Where z is the sag, c is the inverse of the radius of curvature, r is the radial distance of a point on the mirror surface, k is the quadratic surface constant, and A, B, C, D, E, F, G, H, and I are the coefficients of higher-order terms.

[0115] The aspheric coefficients are shown in Table 4 (the coefficients not shown in the table are assumed to be 0 by default):

[0116] Table 4

[0117] Seventh lens 37-01Seventh lens 37-02Sixth lens 36-01Sixth lens 36-02Fifth lens 35-01Fifth lens 35-02Second imaging lens unit 8-01Second imaging lens unit 8-02Conic Constant (k)-0.573299960599881-0.4573096397948252.364538312128151.539948119075480.426510005836866-1.62864353639823-4.32765551203199-104th Order Coefficient (A)2.28138789781744e-050.0001052507805745564.54592360253419e-050.0001491130519716453 .06093670414771e-05-6.95077301500439e-05-2.13855807789278e-054.90823134663529e-056th Order Coefficient (B)-1.11349013065964e-072.06558024738919e-071.14389668314152e-064.3769285077919e-0 71.5609458936106e-077.73188080043877e-082.87178495511286e-075.01042206957926e-078th Order Coefficient (C)-1.53254051897019e-09-1.68992049411875e-09-9.28486815277614e-09-2.02245662227915e-0 8-1.73183537136066e-091.75156178508178e-10-5.13452654583947e-091.05971960640861e-0810th Order Coefficient (D)5.85660543013003e-12-2.78333713644525e-11-8.21300906354144e-11-7.97630631717531e-1 13.9937849209076e-11-2.45536515469988e-136.02192503487512e-11-7.1722496657418e-1112th Order Coefficient (E)1.91698696565243e-132.17283206166655e-137.70537176033126e-13-4.60289859 838435e-12-3.42253110075976e-13-9.88629225682231e-14-4.32765551203199.

[0118] The XY polynomial surface shape satisfies the following equation:

[0119]

[0120] Where Z is the sagittal height, K is the quadratic constant, K=1.2, X is the sagittal coordinate, Y is the meridian coordinate, m and n represent the order and range from 0 to 10, C j is a monomial The coefficient of X is shown in Table 5. 1 and Y 0 The coefficient of the corresponding column is 0, and the same applies to the others.

[0121] The XY polynomial coefficients are shown in Table 5:

[0122] Table 5

[0123] X 0 X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 Y 0 / 0-0.01639484097819010-1.23256229903057e-060-4.20833374445727e-110-1.98494373496958e-1300Y 1 00-2.3234896688029e-060-6.25811320827282e-0901.12228561017606e-11000Y 2 -0.01408856285170380-1.80105436546568e-060-3.86443260813023e-100-4.44376850621759e-1300Y 3-3.70921368716343e-060-7.16614415269229e-0903.26786036758807e-11000Y 4 -6.80167093424663e-070-6.54572701914e-100-6.7277763409068e-1400Y 5 6.42889693931955e-1002.90794277021085e-11000Y 6 -4.10726836144176e-1003.71658537683578e-1300Y 7 5.54469211078262e-12000Y 8 4.11957765392623e-1300Y 9 00Y 10 0

[0124] According to the above data, as shown in Figure 9, the single-display binocular diopter-adjustable near-eye display system of this embodiment has an MTF greater than 0.2 at 30lp / mm, excellent imaging quality, a field of view angle FOV of 50°~55°, and an eye movement range EYEBOX of 10*6~12*8.

[0125] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The above-described embodiments merely represent specific and detailed examples of the present application and should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A single-display binocular near-eye display system with adjustable diopter, Features: The single-display binocular diopter-adjustable near-eye display system comprises a display (1), a beam splitter prism (2), a first imaging display unit and a second imaging display unit, wherein: The display (1) is used to emit imaging light and to move relative to the beam splitter prism (2) to achieve diopter adjustment; The beam splitter prism (2) is used to split the imaging light emitted by the display (1) into two paths, and the two paths of imaging light are incident on the imaging display unit in a one-to-one correspondence; Each of the imaging display units corresponds to a human eye one by one, and comprises a first imaging lens unit (3), a plane reflector (4) and a curved mirror (6); the first imaging lens unit (3) comprises at least one lens; the plane reflector (4) is arranged to be inclined relative to the optical axis of the first imaging lens unit (3); a mirror surface of the curved mirror (6) away from the human eye is coated with a light-splitting film, and a mirror surface close to the human eye is coated with an anti-reflection film; and the curved mirror (6) meets the following conditions: 10mm<|f1|<30mm, 1.2mm <CT1<2mm,42mm<L<50mm,1.8<L / D<2.1; Wherein, f1 is the focal length of the curved mirror (6), CT1 is the thickness of the curved mirror (6), L is the length of the curved mirror (6), that is, the distance of the curved mirror (6) in the left-right direction when worn by a human body, and D is the width of the curved mirror (6), that is, the distance of the curved mirror (6) in the up-down direction when worn by a human body; After the imaging light corresponding to the imaging display unit passes through the first imaging lens unit (3), it is reflected by the plane reflector (4) to the curved mirror (6), and then reflected by the curved mirror (6) to the human eye, while the external light passes through the curved mirror (6) and enters the human eye.

2. The single-display binocular diopter-adjustable near-eye display system according to claim 1, Features: The imaging display unit further comprises a plane mirror imaging unit (5), the plane mirror imaging unit (5) being arranged to be inclined relative to a first optical axis and having an inclination angle of 30° to 60°, the first optical axis being a line connecting the center of a corresponding human eye and the center of the curved mirror (6), the plane mirror imaging unit (5) comprising a plane mirror, a side close to the curved mirror (6) being provided with a semi-transmissive semi-reflective film or a first polarizing unit, and a side away from the curved mirror (6) being provided with an anti-reflection film, the first polarizing unit being at least one of a polarizing film, a polarizing reflection film, a phase delay film and an anti-reflection film.

3. The single-display binocular diopter-adjustable near-eye display system according to claim 2, Features: The first polarization unit includes a polarization reflection film, a phase delay film and a polarization film which are attached in sequence.

4. The single-display binocular diopter-adjustable near-eye display system according to claim 1, Features: The first imaging lens unit (3) satisfies -15 mm ≤ f0 ≤ -6 mm, where f0 is the focal length of the first imaging lens unit (3).

5. The single-display binocular diopter-adjustable near-eye display system according to claim 4, Features: The first imaging lens unit (3) comprises a first lens (31), a second lens (32), a third lens (33) and a fourth lens (34) which are arranged in sequence along the light propagation direction, the first lens (31) is a glass spherical lens with negative focal length, the second lens (32) is a glass spherical lens with positive focal length, the third lens (33) is a plastic aspherical lens with negative focal length, and the fourth lens (34) is a glass spherical lens with negative focal length, and the following conditions are satisfied: 10mm<|f2|<25mm, 1mm <CT2<3mm,1<CT2 / ET2<1.5; 7mm<|f3|<15mm, 0.5mm <CT3<3mm,0.6<CT3 / ET3<1; 10mm<|f4|<20mm, 0.5mm <CT4<3mm,H / h<3; 10mm<|f5|<20mm, 1mm <CT5<3mm,0.7<CT5 / ET5<1.5; wherein f2 is the focal length of the first lens (31), CT2 is the center thickness of the first lens (31), ET2 is the edge thickness of the first lens (31), f3 is the focal length of the second lens (32), CT3 is the center thickness of the second lens (32), ET3 is the edge thickness of the second lens (32), f4 is the focal length of the third lens (33), CT4 is the center thickness of the third lens (33), H is the maximum thickness of the third lens (33), H=CT4, h is the minimum thickness of the third lens (33), f5 is the focal length of the fourth lens (34), CT5 is the center thickness of the fourth lens (34), and ET5 is the edge thickness of the fourth lens (34).

6. The single-display binocular diopter-adjustable near-eye display system according to claim 1, Features: The first imaging lens unit (3) satisfies 10 mm ≤ f0 ≤ 20 mm, where f0 is the focal length of the first imaging lens unit (3).

7. The single-display binocular diopter-adjustable near-eye display system according to claim 6, Features: The first imaging lens unit (3) comprises a fifth lens (35), a sixth lens (36) and a seventh lens (37) which are arranged in sequence along the light propagation direction, the fifth lens (35) is a plastic aspheric lens with positive focal length, the sixth lens (36) is a plastic aspheric lens with negative focal length, and the seventh lens (37) is a plastic aspheric lens with positive focal length, and the following conditions are satisfied: 12mm<|f6|<15mm, 4mm <CT6<5.5mm,1.8<CT6 / ET6<4; 12mm<|f7|<15mm, 0.7mm <CT7<1.5mm,2<ET7 / CT7<5; 12mm<|f8|<15mm, 4.5mm <CT8<6.2mm,1<CT8 / ET8<3; wherein f6 is the focal length of the fifth lens (35), CT6 is the center thickness of the fifth lens (35), ET6 is the edge thickness of the fifth lens (35), f7 is the focal length of the sixth lens (36), CT7 is the center thickness of the sixth lens (36), ET7 is the edge thickness of the sixth lens (36), f8 is the focal length of the seventh lens (37), CT8 is the center thickness of the seventh lens (37), and ET8 is the edge thickness of the seventh lens (37).

8. The single-display binocular diopter-adjustable near-eye display system according to claim 1, Features: The single-display binocular diopter-adjustable near-eye display system further comprises a second imaging lens unit (8), the second imaging lens unit (8) comprises at least one lens, and the focal length of the second imaging lens unit (8) is -130 mm ≤ f ≤ -100 mm, and the imaging light emitted by the display (1) passes through the second imaging lens unit (8) and enters the beam splitting prism (2).

9. The single-display binocular diopter-adjustable near-eye display system according to claim 1, Features: The mirror surface of each lens on the first imaging lens unit (3) is coated with an anti-reflection film and the optical axis is arranged horizontally.

10. The single-display binocular diopter-adjustable near-eye display system according to claim 1, Features: The mirror surface of the curved mirror (6) is a spherical surface, an aspherical surface or a free-form surface, the transmittance-reflection ratio of the beam splitting film on the curved mirror (6) is 1:4 to 1:1, and the reflectivity of the anti-reflection film on the curved mirror (6) is less than 1%.

Images