A human-eye-simulated test conic lens

Abstract

The application discloses a kind of human eye test conoscopy, comprising: front light barrier, the light aperture of the light barrier is not more than 4mm;Imaging lens group, close to object plane, with positive focal length, can be not less than 120 degree field of view incident light rays converge into, and form approximate telecentric intermediate image in rear;Relay lens group, close to image plane, with less than 1 magnification, for imaging intermediate image at image plane;The focal length GF1 of the imaging lens group is less than 16.2mm, the focal length GF1 of imaging lens group and the focal length GF2 of relay lens group satisfy the following relationship: 0.2<GF1 / GF2<0.3;Imaging circle diameter is D1, and the diameter of diaphragm is D2, satisfy: 8<D1 / D2<10.The above-mentioned human eye test conoscopy can realize similar test effect with direct observation of human eye, suitable for testing near-eye display device, and can meet the imaging effect of large image plane, high resolution and no vignetting.

Description

Technical Field

[0001] This invention relates to a human eye-inspired test cone lens, belonging to the field of test lenses. Background Technology

[0002] With the continuous expansion of the field of view and the continuous improvement of image clarity in Augmented Reality (AR) and Virtual Reality (VR) display systems, AR and VR imaging and detection equipment has also developed rapidly. A conical lens is an imaging objective with a front-aperture stop, located in front of all lenses. It can directly interface with AR / VR devices to simulate the imaging process of the human eye.

[0003] Existing conical lenses generally suffer from small imaging target areas, low resolution, and severe vignetting at the edges of the field of view, failing to meet the current VR / AR device inspection industry's requirements for large target areas and high-resolution imaging. Furthermore, the small aperture of existing conical lenses prevents them from realistically simulating the light transmission process of the human eye, hindering their ability to meet the ever-increasing inspection requirements of AR / VR devices. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a human eye-inspired test conical lens.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0006] A human eye-inspired test cone lens includes:

[0007] A front aperture, wherein the aperture diameter of the aperture does not exceed 4mm;

[0008] The imaging lens group, located close to the object plane and having a positive focal length, can converge incident light rays with a field of view of not less than 120 degrees, forming an approximately telecentric intermediate image at the rear; and

[0009] The relay lens group, located close to the image plane, has a magnification of less than 1 and is used to image the intermediate image onto the image plane.

[0010] The focal length GF1 of the imaging lens group is less than 16.2 mm, and the focal length GF1 of the imaging lens group and the focal length GF2 of the relay lens group satisfy the following relationship: 0.2 <GF1 / GF2<0.3;

[0011] The imaging circle diameter is D1, and the aperture diameter is D2, satisfying: 8 <D1 / D2<10。

[0012] Preferably, the imaging lens group includes a first positive-negative cemented lens and two positive lenses. Among them, the first positive-negative cemented lens is closest to the aperture stop, the negative lens is close to the object surface and is made of flint glass, the positive lens is close to the image surface and is made of crown glass. The object-side surface of the negative lens is concave and the surface curvature radius is between -20 mm and -10 mm, and the image-side surface of the positive lens is convex and the curvature radius is between 10 mm and 20 mm.

[0013] Preferably, the relay lens group includes a first lens group, a second lens group and a third lens group. Among them, the focal length of the first lens group is positive to compress the light passing aperture of the beam, and the second lens group and the third lens group are used to correct aberrations. The focal length of the second lens group is F2, the focal length of the third lens group is F3, and the distance d 23 satisfies 20 mm < d 23 < F3 - F2.

[0014] Preferably, the first lens group includes a second positive-negative cemented lens, a positive lens and a third positive-negative cemented lens. Among them, the third positive-negative cemented lens is composed of two lenses made of flint glass with similar refractive indices and Abbe numbers cemented together;

[0015] The second lens group includes a fourth positive-negative cemented lens and a positive lens. Among them, the fourth positive-negative cemented lens is composed of two lenses made of flint glass with similar refractive indices and Abbe numbers cemented together;

[0016] The surface profiles of two adjacent surfaces of the third positive-negative cemented lens and the fourth positive-negative cemented lens are approximately symmetric and concave towards the symmetry center respectively.

[0017] Preferably, the third lens group includes a fifth positive-negative cemented lens, a positive lens, a sixth positive-negative cemented lens and a negative lens arranged from the object-side to the image-side.

[0018] Preferably, the lens closest to the image surface in the conoscopic lens is a negative lens. The object-side surface and the image-side surface of the negative lens both convex towards the image surface, and moreover, the surface profiles of the object-side surface and the image-side surface are both aspherical surfaces.

[0019] Preferably, the rear focal plane of the imaging lens group and the front focal plane of the relay lens group are curved surfaces and coincide.

[0020] Preferably, the maximum diameter of the conoscopic lens is determined by the height of the intermediate image, and the height of the intermediate image does not exceed 28 mm.

[0021] Preferably, the imaging circle diameter of this lens is D1 and satisfies: 35.6 < D1 < 36; the imaging circle diameter corresponding to a 95-degree field of view is D1', and satisfies D1' < 24 mm.

[0022] Preferably, a folding prism is provided at the intermediate image position between the front imaging system and the rear relay system to achieve optical path folding, wherein the intermediate image intersects with but does not overlap with the reflecting surface of the folding prism.

[0023] The human-eye-inspired test conical lens provided by this invention includes a front aperture, an imaging lens group, and a relay lens group. It has an entrance pupil diameter of no more than 4mm, consistent with the human eye, and can meet the requirements for high-resolution imaging at 6000W pixels on a full-frame screen. This human-eye-inspired test conical lens can be applied to optical display device modules or complete units that require evaluation of visual imaging quality, such as virtual reality near-eye display devices, augmented reality near-eye display devices, and eyepieces. It can meet the testing requirements of near-eye display devices with a monocular diagonal field of view within 120°, and can achieve large image size, high resolution, and vignetting-free imaging effects. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the human eye-inspired test conical lens provided by the present invention;

[0025] Figure 2 for Figure 1 The diagram shows the optical path of the human eye-inspired test conical lens.

[0026] Figure 3 for Figure 1 The field curvature diagram of the human eye-inspired test conical lens under visible light is shown.

[0027] Figure 4 for Figure 1 The distortion diagram of the human eye-inspired test conical lens under visible light is shown.

[0028] Figure 5 for Figure 1 The diagram shows the MTF-frequency curve of the human eye-inspired test conical lens at infinity under visible light.

[0029] Figure 6 for Figure 1 The MTF-frequency curve of the human eye-inspired test conical lens under visible light at a distance of 1 meter is shown.

[0030] Figure 7 for Figure 1 The defocus MTF curve of the human eye-inspired test conic lens under visible light is shown.

[0031] Figure 8 for Figure 1 The MTF-field curves of the human eye test conic lens under visible light for 65 line pairs and 130 line pairs are shown.

[0032] Figure 9This is a structural diagram of another human eye-inspired test conical lens provided by the present invention;

[0033] Figure 10 for Figure 9 A schematic diagram of the structure of a right-angle prism;

[0034] Figure 11 for Figure 9 The diagram shows the optical path of the human eye-inspired test conical lens.

[0035] Figure 12 The optical path diagram is shown after an aperture stop is installed on the test lens at the incident aperture stop, which is used to simulate the imaging state of the human eye under pupil constriction conditions.

[0036] Figure 13 for Figure 1 The diagram shows the MTF-frequency curve of the human eye test cone lens with a 2mm aperture stop, operating at a 2mm entrance pupil diameter and visible light at infinity.

[0037] Figure 14 for Figure 1 The diagram shows the MTF-frequency curve of the human eye test conical lens with a 1mm aperture stop, operating at an entrance pupil diameter of 1mm and visible light at infinity. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that the phrase "a lens has a positive refractive index (or a negative refractive index)" refers to the lens having a positive (or negative) paraxial refractive index calculated using Gaussian optics theory. The "object-side surface or image-side surface of the lens" is defined as the specific range through which imaging rays pass on the lens surface. The convexity or concavity of a lens surface can be determined using the conventional method in this field, namely by the sign of the radius of curvature (R-value). The R-value is commonly used in optical design software, such as Zemax or CodeV. The R-value is also commonly found in lens datasheets within optical design software. For the object-side surface, a positive R-value indicates a convex surface, while a negative R-value indicates a concave surface. Conversely, for the image-side surface, a positive R-value indicates a concave surface, while a negative R-value indicates a convex surface.

[0040] In addition, if descriptions such as "first" and "second" are involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or inability to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] The artificial eye test conoscopic lens provided by the embodiments of the present application can be applied to optical display device modules or complete machines such as virtual reality near-eye display devices, augmented reality near-eye display devices, and eyepieces that require evaluating visual imaging quality, and can meet the test of near-eye display devices with a monocular diagonal field angle within 120°. It has an entrance pupil diameter of 4 mm, which is the same as that of the human eye, and can meet the high-resolution imaging of a full-frame 60 million pixels.

[0042] As Figure 1 and Figure 2 As shown, the artificial eye test conoscopic lens (hereinafter referred to as the conoscopic lens) provided by the present invention includes: a front aperture 21, an imaging lens group 100, and a relay lens group 200. The aperture 21 is located at the front end of the system. The incident parallel light enters the conoscopic lens through the aperture, and the imaging plane is located in the region near the image-side focus of the system. The clear aperture of the front aperture is equal to 4 mm, and the clear aperture of the front aperture 21 can be reduced by adding an aperture stop with a clear aperture of 2 mm or 1 mm at the incident aperture for the test lens; the imaging lens group 100, close to the object plane, has a positive focal length and functions to converge, and can converge incident light rays with a field angle of not less than 120 degrees and form an approximately telecentric intermediate image at the rear; the relay lens group 200, close to the image plane, has a magnification less than 1, and is used to image the intermediate image at the image plane and further correct aberrations to optimize the imaging quality. The conoscopic lens adopts a structure combining a catadioptric lens group and a relay lens group, which reduces the external size of the system while achieving good imaging quality. Among them, the focal length GF1 of the imaging lens group 100 is less than 16.2 mm, and the focal length GF1 of the imaging lens group 100 and the focal length GF2 of the relay lens group 200 satisfy the following relationship: 0.2 < GF1 / GF2 < 0.3; the imaging circle diameter of this lens is D1, and the aperture diameter is D2, satisfying: 8 < D1 / D2 < 10.

[0043] Specifically, the imaging lens group 100 is a catadioptric structure, including a first positive-negative cemented lens (composed of a negative lens 1 and a positive lens 2) and two positive lenses. Among them, the first positive-negative cemented lens is closest to the aperture stop, the negative lens 1 is close to the object surface and is made of flint glass, the positive lens 2 is close to the image surface and is made of crown glass; the outermost surfaces of the negative lens 1 and the positive lens 2 (i.e., the object-side surface of the negative lens 1 and the image-side surface of the positive lens 2) are both concave toward the object surface, and the curvature radii of the outermost surfaces of the negative lens 1 and the positive lens 2 determine the incident angle of the convergent light rays of this conoscopic lens. To meet the test requirement that the incident angle is not less than 120°, the curvature radius R1 of the object-side surface of the negative lens 1 is between -20 mm and -10 mm, and the absolute value of the curvature radius is greater than the distance from the aperture stop 21 to the negative lens 1, which deflects the incident light of the large field of view toward the optical axis direction. The image-side surface of the positive lens 2 is convex and the curvature radius R2 is between 10 mm and 20 mm, and the thickness of the positive-negative cemented lens is between 12 mm and 19 mm.

[0044] The relay lens group 200 includes a first lens group 201, a second lens group 202, and a third lens group 203. Among them, the focal length of the first lens group 200 is positive to compress the light aperture of the beam, and the second lens group 202 and the third lens group 203 are used to correct aberrations; the focal length of the second lens group is F2, the focal length of the third lens group is F3, and the distance d 23 satisfies 20 mm < d 23 < F3 - F2.

[0045] The first lens group 201 includes a second positive-negative cemented lens, a positive lens, and a third positive-negative cemented lens. Among them, the second positive-negative cemented lens close to the object surface side includes a positive lens 6 and a negative lens 7 for achromatism correction; the positive lens 8 is used to achieve the effect of beam contraction, and the curvature radius of the object-side surface of the positive lens 8 satisfies 30 mm < R8 < 40 mm; the third positive-negative cemented lens closest to the image surface side is formed by cementing lens 9 and 10, and lens 9 and lens 10 are made of two flint glasses with relatively close refractive indices and Abbe numbers (the Abbe number is close to 30). The above cemented lenses effectively correct the chromatic aberration of the system, and by splitting the concentric lens into a double-cemented form, the problem of difficult centering caused by using a concentric lens is avoided; the second lens group 201 is used to compress the beam diameter and achieve a magnification of less than 1 for the relay lens group. The focal length F1 of the first lens group satisfies 55 mm < F1 < 75 mm.

[0046] The second lens group 202 includes a fourth positive-negative cemented lens and a positive lens 13. The fourth positive-negative cemented lens near the object plane is formed by cementing lenses 11 and 12. Lenses 11 and 12 are made of two flint glasses with similar refractive indices and Abbe numbers (Abbe number close to 30). The cemented lens effectively corrects the chromatic aberration of the system and avoids the problem of difficulty in centering caused by using concentric lenses by splitting the concentric lens into a double cemented form.

[0047] The surface shapes of two adjacent surfaces of the first lens group and the second lens group are approximately symmetrical, specifically: Figure 1 Both the image-side surface of the middle lens 10 and the object-side surface of the lens 11 are concave, concave towards the center of symmetry. The difference in the absolute value of their radii of curvature is less than 7 mm, which is beneficial for eliminating transverse aberrations such as astigmatism and coma. The center of symmetry of this symmetrical structure is located between the image-side surface of the negative lens 10 and the object-side surface of the negative lens 11. Relative to the center of symmetry, the third positive-negative cemented doublet composed of the positive lens 9 and the negative lens 10, and the fourth positive-negative cemented doublet composed of the negative lens 11 and the positive lens 12, are both made of flint glass. The aforementioned center of symmetry is located in the middle of the entire conical lens, with nine lenses before and after the center of symmetry.

[0048] The third lens group 203 includes a fifth positive-negative cemented lens (composed of negative lens 14 and positive lens 15), a positive lens 16, a sixth positive-negative cemented lens (composed of negative lens 17 and positive lens 18), and a negative lens 19 arranged from the object plane side to the image plane side. The two positive-negative cemented lenses are used to correct chromatic aberration. The negative lens 19 is used to diverge the light beam to the image plane 20 and further correct aberrations. The lens closest to the image plane in the conical lens is the negative lens 19. The object-side and image-side surfaces of the negative lens 19 are both convex to the image plane, and both the object-side and image-side surfaces are aspherical, which helps with field curvature correction.

[0049] In the aforementioned conical lens, the rear focal plane of the imaging lens group 100 and the front focal plane of the relay lens group 200 are both curved surfaces and coincide. The conical lens forms an intermediate image plane at the rear focal plane of the imaging lens group 100. Field curvature exists on the intermediate image plane, resulting in a curved surface convex towards the object plane. The distance between the imaging lens group 100 and the relay lens group 200 is d. 12 The sum of the back focal length of the imaging lens group 100 and the front focal length of the relay lens group 200 is 0.9d. 12 ~1.1d 12 between.

[0050] The maximum diameter of the conoscopic lens is determined by the height of the intermediate image, and the image height of the intermediate image does not exceed 28 mm. Thus, the diameter of the distribution range of the intermediate image does not exceed 56 mm. The distance between the optical axes of two juxtaposed conoscopic lenses does not exceed 56 mm, which is less than the pupil distance of a normal human eye. Therefore, when testing a binocular near-eye display device, the two sets of conoscopic lenses can be placed side by side to meet the requirement of simultaneous binocular detection. According to the 120-degree field of view and the intermediate image height less than 28 mm, the focal length GF1 of the imaging lens group 100 can be calculated to be less than 16.2 mm.

[0051] In this conoscopic lens, the diameters of the lens 4 facing the image plane in the imaging lens group 100, the second positive-negative cemented lens (composed of a positive lens 6 and a negative lens 7) in the first lens group 201, and the positive lens 8 should all meet the imaging requirements of the intermediate image. The diameters of the above-mentioned multiple lenses are close to the diameter of the distribution range of the intermediate image, and their diameters should all be between 50 mm and 56 mm. This diameter has a margin of not less than 4 mm relative to the pupil distance of 60 mm to 65 mm of the human eye. Considering the thickness of the lens barrel housing, the two sets of lenses can still be placed side by side to achieve the function of simultaneous detection of the binocular imaging system.

[0052] The imaging circle diameter of this conoscopic lens is D1, and it satisfies: 35.6 mm < D1 < 36 mm, corresponding to the long side length of 36 mm of a full-frame CMOS. The lens imaging circle covers the long side of the full-frame CMOS, and most of the field of view is imaged on the CMOS, avoiding a certain amount of cropping loss. The imaging circle diameter corresponding to the 95-degree field of view of this conoscopic lens is D1', and it satisfies D1' < 24 mm, corresponding to the short side length of 24 mm of a full-frame CMOS. The 95-degree field of view is a typical field of view of a pancake structure optical system. The conoscopic lens can combine with a full-frame CMOS to detect the 95° full field of view without field of view cropping loss.

[0053] The entrance pupil diameter D of this conoscopic lens satisfies: D ≤ 4 mm. The entrance pupil diameter of 4 mm is similar to the physiological structure of the human eye. By installing aperture stops with different light passing apertures (such as 1 mm, 2 mm, 4 mm) in front of the lens, different entrance pupil diameters can be combined to better simulate the imaging effects of different pupil diameters of the human eye under different ambient light intensities. The imaging effects of this conoscopic lens can be guaranteed for aperture stops with different light passing apertures not exceeding 4 mm.

[0054] The overall optical length OAL of this conoscopic lens satisfies: OAL > 318 mm and OAL / D L1 <25, where D L1 is the outer diameter of the first lens. The conoscopic lens has a relatively long overall system length, which is beneficial to correcting axial aberration.

[0055] The vignetting coefficient of this conical lens satisfies the condition: VY < 0.01, where VY is the vignetting coefficient in the meridional direction. The near-zero vignetting coefficient of the optical system indicates a vignetting-free design, maximizing the system's full-field illumination.

[0056] The conical lens has been optimized for object distances from 1000mm to infinity. By adjusting the distance between the CMOS and the conical lens, i.e., adjusting the back focal length of the conical lens, the travel can be adjusted to between 2mm and 3mm to meet the requirements of the conical lens for object-image matching detection in AR / VR systems with different virtual image distances, corresponding to imaging at object distances from 1000mm to infinity.

[0057] This invention provides two embodiments of conical lenses. Embodiment 1 is a coaxial structure, and Embodiment 2 is a folding structure. The folding structure can effectively reduce the system length, facilitating AR / VR whole-device testing. Both Embodiment 1 and Embodiment 2 have an entrance pupil diameter of 4mm, consistent with the human eye, which can meet the requirements of full-frame 6000w pixel high-resolution imaging.

[0058] Example 1

[0059] Example 1 provides a human eye-like test conical lens with a coaxial structure, including a front aperture 21, an imaging lens group 100, a plane lens 5, and a relay lens group 200.

[0060] Specifically, such as Figure 1 The conical lens shown includes nineteen lenses arranged sequentially along the optical axis from the object side to the image side. Among them, the first lens 1 and the second lens 2 are cemented together, the sixth lens 6 and the seventh lens 7 are cemented together, the ninth lens 9 and the tenth lens 10 are cemented together, the eleventh lens 11 and the twelfth lens 12 are cemented together, the fourteenth lens 14 and the fifteenth lens 15 are cemented together, and the seventeenth lens 17 and the eighteenth lens 18 are cemented together.

[0061] The first lens 1 to the nineteenth lens 19 each include an object-side surface facing the object and an image-side surface facing the image.

[0062] In the imaging lens group 100 of the front-mounted eyepiece structure, the first lens 1 and the second lens 2 form a first positive-negative cemented doublet lens, which plays an achromatic role. The first lens 1 is made of flint glass, with a concave object surface and a convex image surface. The second lens 2 is made of crown glass, with a concave object surface and a convex image surface. The third lens 3 has a positive focal length and plays a converging role. The object surface of the third lens is concave and the image surface is convex. The fourth lens 4 has a positive focal length and plays a converging role. The object surface of the fourth lens 4 is convex and the image surface is convex.

[0063] A fifth lens 5 is disposed between the imaging lens group 100 and the relay lens group 200. The fifth lens 5 is a flat prism, and both its object-side and image-side surfaces are flat. The inclusion of the fifth lens 5 simplifies the optimization design process of Embodiment 2. In a standalone conical lens, the fifth lens 5 can be omitted or placed. Adding the fifth lens 5 can reduce the total optical length (OAL) of the conical lens to a certain extent. Furthermore, the inclusion of the fifth lens 5 in the conical lens, which is a thick flat lens, provides space for the subsequent addition of a folding prism to achieve lens folding. The folding prism is an isosceles right-angle prism with an aperture diameter equal to the equivalent thickness of the fifth lens 5, and must meet the size requirements for binocular side-by-side placement. The thickness of the fifth lens 5 is between 56mm and 58mm.

[0064] In the rear relay lens group 200, the first lens group 201 includes the following lenses: the sixth lens 6 and the seventh lens 7 form a second positive-negative cemented lens, which serves to achromatic, and the material of the sixth lens 6 is crown glass, with a convex object surface and a convex image surface; the material of the seventh lens 7 is flint glass, with a concave object surface and a convex image surface; the eighth lens 8 has a positive focal length and serves to converge, and the object surface of the eighth lens 8 is convex, while the image surface is flat; the ninth lens 9 and the tenth lens 10 form a third positive-negative cemented lens, which serves to achromatic, and the material of the ninth lens 9 is flint glass, with a convex object surface and a convex image surface; the material of the tenth lens 10 is flint glass, with a concave object surface and a concave image surface.

[0065] The second lens group 202 includes the following lenses: the eleventh lens 11 and the twelfth lens 12 form a fourth positive-negative cemented lens, which serves to achromatic. The eleventh lens 11 is made of flint glass, with a concave object surface and a concave image surface. The twelfth lens 12 is also made of flint glass, with a convex object surface and a convex image surface. The thirteenth lens 13 has a positive focal length and serves to converge. The thirteenth lens 13 has a convex object surface and a convex image surface.

[0066] The third lens group 203 includes the following lenses: the fourteenth lens 14 and the fifteenth lens 15 form the fifth positive-negative cemented lens, which serves to achromatic, and the fourteenth lens 14 is made of flint glass with a concave object surface and a concave image surface; the fifteenth lens 15 is made of crown glass with a convex object surface and a convex image surface; the sixteenth lens 16 has a positive focal length and serves to converge, and the sixteenth lens 16 has a convex object surface and a convex image surface; the seventeenth lens 17 and the eighteenth lens 18 form the sixth positive-negative cemented lens, which serves to achromatic, and the seventeenth lens 17 is made of flint glass with a convex object surface and a concave image surface; the eighteenth lens 18 is made of crown glass with a convex object surface and a concave image surface; the nineteenth lens 19 has a negative focal length and serves to diverge, and the nineteenth lens 19 has a concave object surface and a convex image surface.

[0067] A protective glass 20 is provided in front of the image surface of the conical lens. The protective glass 20 is a flat lens with a flat object surface and a flat image surface.

[0068] In this conical lens, the Abbe numbers of multiple lenses satisfy the following conditions: V1 < 20, V2 > 65, V6 > 50, V7 < 20, V14 < 30, V15 > 65, V17 < 30, V18 > 65. Here, V1, V2, V6, V7, V14, V15, V17, and V18 are the Abbe numbers of the first lens 1, the second lens 2, the sixth lens 6, the seventh lens 7, the fourteenth lens 14, the fifteenth lens 15, the seventeenth lens 17, and the eighteenth lens 18, respectively. The second lens 2, the sixth lens 6, the fifteenth lens 15, and the eighteenth lens 18 all have high Abbe numbers, which is beneficial for eliminating chromatic aberration.

[0069] The nineteenth lens 19 is an aspherical lens. Using an aspherical lens is beneficial for correcting field curvature in the system. Both its object-side and image-side surfaces are even-order aspherical surfaces, expressed as follows:

[0070]

[0071] Where Sag is the surface height, c is the surface curvature radius, k is the conic coefficient, r is the radial coordinate, E1 is the fourth-order aspheric coefficient, E2 is the sixth-order aspheric coefficient, E3 is the eighth-order aspheric coefficient, E4 is the tenth-order aspheric coefficient, and E5 is the twelfth-order aspheric coefficient.

[0072] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0073] This conical lens employs a 19-element lens combination to correct system aberrations to a low level, improving lens resolution and supporting 60-megapixel full-frame CMOS cameras. The lens features a vignetting-free design to ensure consistent image brightness. Its 4mm entrance pupil diameter matches the working distance of the human eye. By adjusting the objective lens back focal length, it can guarantee image quality from 1000mm to infinity, matching the virtual image distance of common AR / VR devices. The lens combines an eyepiece with a relay system to achieve good image quality. By controlling the lens outer diameter to be smaller than the human eye's interpupillary distance, the lenses can be placed side-by-side for simultaneous binocular detection.

[0074] Tables 1 and 2 show a set of exemplary optical parameters provided in Embodiment 1 of the present invention. The optical surfaces, from the aperture stop to the image plane, are sequentially defined as surface 1, surface 2, ..., surface 36, where surface 1 is the aperture stop; surface 2 is the object-side surface of the first lens 1; surface 3 is the image-side surface of the first lens 1 and also the object-side surface of the second lens 2; surface 4 is the image-side surface of the second lens 2; and so on, surface 32 is the object-side surface of the nineteenth lens 19, surface 33 is the image-side surface of the nineteenth lens 19, and surface 36 is the image plane.

[0075] Table 1 shows the optical surface parameters of the human eye-inspired test conical lens in Example 1.

[0076]

[0077]

[0078] Table 2 Aspherical parameters of the object surface 32 and image surface 33 of the nineteenth lens

[0079]

[0080]

[0081] In this embodiment, the system focal ratio F / D = 3.8, the total optical length OAL = 318.4 mm, the image height h = 17.8 mm, and the focal length F = 15.2 mm.

[0082] Please refer to the field curvature curve of this conical lens under visible light. Figure 3 As can be seen from the figure, the field curvature curves of different wavelengths in the entire field of view are distributed within ±10um in the axial direction, indicating that the lens axial chromatic aberration correction is relatively good.

[0083] Please refer to the distortion curve of this conical lens under visible light. Figure 4 As can be seen from the figure, the distortion of the conical lens is 30% at the maximum field of view. The larger distortion is beneficial to improving the uniformity of illumination across the entire field of view.

[0084] Please refer to the MTF curve of this conical lens under visible light. Figure 5 and Figure 6 .from Figure 5 As can be seen, when imaging at infinity, this lens has an MTF value of approximately 0.45 at a spatial frequency of 65 lp / mm and an MTF value of approximately 0.1 at a spatial frequency of 130 lp / mm. From... Figure 6 As can be seen, when imaging at a distance of 1 meter, this lens has an MTF value of around 0.4 at a spatial frequency of 65 lp / mm and an MTF value of around 0.1 at a spatial frequency of 130 lp / mm. This lens maintains good resolution at different object distances, which meets current application requirements.

[0085] Please refer to the defocus MTF curve of this conical lens under visible light. Figure 7 As can be seen from the figure, the peak MTF of each field of view of the system is concentrated within ±0.02mm of the paraxial focal point, which is relatively concentrated.

[0086] Please refer to the MTF field of view of this conical lens under visible light. Figure 8 As can be seen from the figure, the meridian curve and the sagittal curve overlap very well near the central field of view. When the line pairs are 65, the overall MTF is around 0.5, and when the line pairs are 135, the overall MTF is around 0.3.

[0087] Example 2

[0088] Reference Figures 9 to 11 As shown, Embodiment 2 provides a human eye-like test conical lens with optical path folding, including a front aperture 21, an imaging lens group 100, a folding prism 5A, and a relay lens group 200. Compared with Embodiment 1, the optical path is folded by replacing the planar lens 5 with the folding prism 5A, thereby changing the conical lens from a coaxial structure to a folding structure, thus reducing the lens length and meeting the overall testing requirements of binocular imaging equipment.

[0089] In this embodiment, the parameters of the front aperture 21, the imaging lens group 100, and the relay lens group 200 are the same as those used in the first embodiment. The following description focuses on the setting of the folding prism 5A.

[0090] like Figure 9 and Figure 10 As shown, in this conical lens, a folding prism 5A is disposed between the front imaging lens group 100 and the relay lens group 200 at the intermediate image position to achieve optical path folding. The intermediate image intersects with but does not coincide with the reflecting surface 502 of the folding prism 5A. The folding prism 5A is preferably as follows: Figure 10 The right-angle prism shown.

[0091] Tables 3 and 4 show a set of exemplary optical parameters provided in Embodiment 2 of the present invention. Continuing the surface definition method from Embodiment 1, surfaces identical to those in the first embodiment are represented by the same numbers. The three surfaces of the folding prism 5A are defined as 501, 502, and 503, with surface 501 being the object-side surface of the folding prism 5A, surface 502 being the reflecting surface, and surface 503 being the image-side surface of the folding prism 5B.

[0092] Table 3 shows the optical surface parameters of the human eye-inspired test conical lens in Example 2.

[0093]

[0094]

[0095] Table 4. Aspherical parameters of the object surface 32 and image surface 33 of the nineteenth lens.

[0096] Surface number Conic coefficient 4th order coefficients 6th order coefficients 8th order coefficients 10th order coefficients 12th order coefficients 32 -9.19E-01 1.29E-04 -1.04E-06 2.53E-09 3.44E-12 -3.56E-14 33 0.00E+00 1.40E-04 -8.31E-07 1.19E-09 7.14E-12 -3.00E-14

[0097] The aforementioned conical lens has a system focal ratio of F / D = 3.8, an image height of h = 17.8 mm, and a focal length of F = 15.2 mm.

[0098] The total system length of this conical lens, from the aperture stop to the folding prism 5A (the distance from the aperture surface 1 to the end point of the reflecting surface 502 away from the aperture stop), is OAL1 = 125mm, which allows it to be placed in a binocular imaging system for testing. By moving the position of the folding prism 5A, the total system length of this test lens from the aperture stop to the folding prism 5A can be controlled to not exceed 125mm.

[0099] The lens imaging parameters of the conical lens provided in this embodiment, such as field curvature, distortion, MTF, and field of view, are the same as those in Embodiment 1, and will not be repeated here.

[0100] In real-world scenarios, the human eye adjusts the pupil opening size to regulate the intensity of incident light based on changes in ambient light intensity. To simulate the imaging state of the human eye under pupil constriction conditions, such as... Figure 12 As shown, aperture stops with a light transmission diameter of 2mm and 1mm can be installed at the incident aperture stop for the test lens.

[0101] like Figure 13 As shown, after adding a 2mm aperture stop, the MTF curve of the conical lens was limited by the diffraction effect and decreased to a certain extent compared with the 4mm entrance pupil diameter. This indicates that the imaging quality of the conical lens has reached the diffraction-limited condition and is no lower than that of the human eye. It can simulate the imaging of the human eye with a 2mm entrance pupil diameter.

[0102] like Figure 14As shown, after adding a 1mm aperture stop, the MTF curve of the conical lens was limited by the diffraction effect and decreased to a certain extent compared with the 4mm entrance pupil diameter. This indicates that the imaging quality of the conical lens has reached the diffraction-limited condition and is no lower than that of the human eye. It can simulate the imaging of the human eye with a 1mm entrance pupil diameter.

[0103] In summary, the human-eye-inspired test conical lens provided by this invention can be applied to optical display device modules or complete devices that require evaluation of visual imaging quality, such as virtual reality near-eye display devices, augmented reality near-eye display devices, and eyepieces. The aforementioned conical lens comprises 19 lenses, supporting a 60MP full-frame CMOS camera and achieving high-resolution imaging; it also exhibits no vignetting across the entire field of view and good image brightness consistency; its aperture diameter is 4mm, consistent with that of the human eye. Furthermore, by adjusting the back focal length of the objective lens, it can guarantee imaging quality from 1000mm to infinity, matching the virtual image distance of common AR / VR devices.

[0104] The foregoing has provided a detailed description of the human eye-inspired testing conical lens provided by this invention. Any obvious modifications made by those skilled in the art without departing from the essential content of this invention will constitute an infringement of the patent rights of this invention and will incur corresponding legal liability.

Claims

1. A human eye-inspired test conical lens, characterized in that... Comprising: A front diaphragm, the light transmission aperture of the diaphragm not exceeding 4 mm; An imaging lens group, close to the object surface, having a positive focal length, capable of converging incident light rays with a field of view of not less than 120 degrees and forming an approximately telecentric intermediate image at the rear; And A relay lens group, close to the image surface, having a magnification less than 1, for imaging the intermediate image at the image surface; The focal length GF1 of the imaging lens group is less than 16.2 mm, and the focal length GF1 of the imaging lens group and the focal length GF2 of the relay lens group satisfy the following relationship: 0.2 < GF1 / GF2 < 0.3; The imaging circle diameter is D1, and the diaphragm diameter is D2, satisfying: 8 < D1 / D2 < 10.

2. The conoscopic light lens simulating a human eye according to claim 1, wherein: The imaging lens group includes a first positive-negative cemented lens and two positive lenses. Among them, the first positive-negative cemented lens is closest to the diaphragm, the negative lens is close to the object surface, made of flint glass, the positive lens is close to the image surface, made of crown glass, the object-side surface of the negative lens is concave and the surface curvature radius is between -20 mm and -10 mm, and the image-side surface of the positive lens is convex and the curvature radius is between 10 mm and 20 mm.

3. The conoscopic light lens simulating a human eye according to claim 1 or 2, wherein: The relay lens group includes a first lens group, a second lens group, and a third lens group. The first lens group has a positive focal length to compress the light beam aperture. The second and third lens groups are used to correct aberrations. The second lens group has a focal length of F2, and the third lens group has a focal length of F3. The distance d between the image surface of the second lens group and the object surface of the third lens group is... 23 Meets 20mm <d 23 <F3-F2。 4. The conoscopic light lens simulating a human eye according to claim 3, wherein: The first lens group includes a second positive-negative cemented lens, a positive lens, and a third positive-negative cemented lens. Among them, the third positive-negative cemented lens is formed by cementing two lenses made of flint glass with similar refractive indices and Abbe numbers; The second lens group includes a fourth positive-negative cemented lens and a positive lens. Among them, the fourth positive-negative cemented lens is formed by cementing two lenses made of flint glass with similar refractive indices and Abbe numbers; The surface shapes of two adjacent surfaces of the third positive-negative cemented lens and the fourth positive-negative cemented lens are approximately symmetric and concave towards the center of symmetry respectively.

5. The conoscopic light lens simulating a human eye according to claim 3, wherein: The third lens group includes a fifth positive-negative cemented lens, a positive lens, a sixth positive-negative cemented lens, and a negative lens arranged from the object side to the image side.

6. The conoscopic light lens simulating a human eye according to claim 1 or 5, wherein: The lens closest to the image surface in the conoscopic light lens is a negative lens. The object-side surface and the image-side surface of the negative lens both convex towards the image surface, and the surface shapes of the object-side surface and the image-side surface are both aspherical surfaces.

7. The conoscopic light lens simulating a human eye according to claim 1, wherein: The rear focal plane of the imaging lens group and the front focal plane of the relay lens group are curved surfaces and coincide.

8. The conoscopic light lens simulating a human eye according to claim 1, wherein: The maximum diameter of the conoscopic light lens is determined by the height of the intermediate image, and the height of the intermediate image does not exceed 28 mm.

9. The conoscopic light lens simulating a human eye according to claim 1, wherein: The imaging circle diameter of this lens is D1, and satisfies: 35.6 < D1 < 36; the imaging circle diameter corresponding to a 95-degree field of view is D1', and satisfies D1' < 24 mm.

10. The human eye-inspired test conical lens as described in claim 1, characterized in that: Between the front imaging system and the rear relay system, a folding prism is set at the intermediate image position to achieve optical path folding. The intermediate image intersects with but does not overlap with the reflecting surface of the folding prism.

Images