A VR detection lens

Abstract

The application provides a VR detection lens, which comprises, in sequence from an object side to an imaging surface along an optical axis, an aperture, a first lens group with positive refractive power, a second lens group with negative refractive power, and a third lens group with positive refractive power; the lens satisfies the following conditions: 0.8<=|f20 / f|<=1.5, 33<=|f30 / f|<=40, and 4.0<=|f40 / f|<=5.0, wherein f is the focal length of the detection lens, f20 is the focal length of the first lens group, f30 is the focal length of the second lens group, and f40 is the focal length of the third lens group. The application has higher resolution and a larger field of view, can well simulate human eye observation, and realizes batch rapid detection of VR products.

Description

A VR detection lens Technical Field

[0001] This invention belongs to the field of optical testing technology, and specifically relates to a VR testing lens. Background Technology

[0002] VR (Virtual Reality) technology is based on the real environment, overlaying virtual objects or electronic information to bring virtual objects into the user's physical world. By listening to, seeing, and touching virtual information, users can enhance their perception of the physical world, thereby achieving an "enhanced" effect on reality.

[0003] To provide a seamless, immersive, or lifelike experience, virtual reality (VR) devices heavily rely on the quality of near-eye displays (NEDs). These displays project visual information very close to the user's eyes, covering their entire field of vision. However, this proximity amplifies display imperfections that are typically imperceptible to users at a distance. These subtle display anomalies include: uneven brightness or color, contrast issues, mura (clouding), line and pixel defects, viewing angle differences, and image ghosting / ghosting (or pixel switching response time).

[0004] In recent years, with the development of microdisplays, advanced optics and hardware and software technologies, VR display products have emerged in an endless stream, and the design and application of related products have been studied in depth. However, the methods for image quality detection and evaluation are relatively lagging behind.

[0005] Currently, the most common method for evaluating the image quality of VR products relies on human visual observation. This is prone to subjective judgment and misjudgment, and is unsuitable for large-scale testing. This may further affect the user experience and cause eye fatigue or even motion sickness. To meet users' product quality requirements, advanced optical inspection equipment must be used to test the displays.

[0006] Traditional display testing typically employs imaging luminance meters or point luminance meters. Point luminance meters suffer from low testing efficiency, while imaging luminance meters, with their aperture positioned inside the lens, limit the ability to capture the full field of view of the display and offer a small detection field of view, failing to simulate the human visual experience and thus unsuitable for VR product testing. Therefore, a lens is needed that combines aperture position and lens field of view to cover a field of view approximating human binocular vision, meeting the requirements of VR product testing. Summary of the Invention

[0007] The purpose of this invention is to provide a VR inspection lens with high resolution and a large field of view, which can effectively simulate human eye observation and realize rapid batch inspection of VR products.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A VR detection lens, along the optical axis from the object side to the imaging plane, includes, in sequence: an aperture stop, a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power.

[0010] The lens meets the following conditions:

[0011] 0.8≤|f20 / f|≤1.5, 33≤|f30 / f|≤40, 4.0≤|f40 / f|≤5.0,

[0012] Where f is the focal length of the detection lens, f20 is the focal length of the first lens group, f30 is the focal length of the second lens group, and f40 is the focal length of the third lens group.

[0013] Specifically, the first lens group of the present invention includes four positive lenses; the four positive lenses in the first lens group are all meniscus lenses, and from the direction of the aperture stop, they are respectively a first positive lens, a second positive lens, a third positive lens, and a fourth positive lens, wherein the first three meniscus lenses near the aperture stop have concave surfaces near the direction of light incidence and convex surfaces near the direction of light emission; the fourth meniscus lens has a convex surface near the direction of light incidence and a concave surface near the direction of light emission.

[0014] Specifically, the first lens group of the present invention satisfies the following conditions:

[0015] 6.0≤|f21 / f|≤7.0, 5.0≤|f22 / f|≤6.0, 5.0≤|f23 / f|≤6.0,

[0016] 6.0≤|f²⁴ / f|≤7.0,

[0017] Where f is the focal length of the detection lens, f21 is the focal length of the first positive lens in the first lens group, f22 is the focal length of the second positive lens in the first lens group, f23 is the focal length of the third positive lens in the first lens group, and f24 is the focal length of the fourth positive lens in the first lens group.

[0018] Specifically, the lenses in the second lens group of the present invention include three positive lenses and three negative lenses, which are arranged sequentially from the aperture stop direction as a first negative lens, a second negative lens, a fifth positive lens, a sixth positive lens, a seventh positive lens, and a third negative lens. The first negative lens and the second negative lens are biconcave lenses, and the third negative lens is a convex-concave lens, wherein the surface closer to the incident direction of light is a convex surface, and the surface closer to the exit direction of light is a concave surface.

[0019] Specifically, the second lens group of the present invention satisfies the following conditions:

[0020] 3.5≤|f31 / f|≤4.0, 3.5≤|f32 / f|≤4.0, 6.5≤|f33 / f|≤7.5,

[0021] 5.0≤|f34 / f|≤6.0, 6.5≤|f35 / f|≤7.0, 2.5≤|f36 / f|≤3.5,

[0022] Where f is the focal length of the detection lens, f31 is the focal length of the first negative lens in the second lens group, f32 is the focal length of the second negative lens in the second lens group, f33 is the focal length of the fifth positive lens in the second lens group, f34 is the focal length of the sixth positive lens in the first lens group, f35 is the focal length of the seventh positive lens in the first lens group, and f33 is the focal length of the third negative lens in the second lens group.

[0023] Specifically, the third lens group of the present invention includes two sets of cemented doublet lenses, three positive lenses and one negative lens, wherein the three positive lenses and one negative lens are distributed on both sides of the two sets of cemented doublet lenses, one positive lens is placed on the side of the two sets of cemented doublet lenses closer to the direction of light incidence, and two positive lenses and one negative lens are placed on the side of the two sets of cemented doublet lenses closer to the direction of light emission.

[0024] Specifically, in the first lens group of the present invention, the Abbe number of the first positive lens is less than 40, and the Abbe numbers of the second, third and fourth positive lenses are greater than 50.

[0025] Specifically, in the second lens group of the present invention, the Abbe numbers of the first to third negative lenses are all less than 30, and the Abbe numbers of the sixth to eighth positive lenses are all greater than 40.

[0026] Specifically, in the third lens group of the present invention, both sets of cemented doublet lenses are composed of cemented glass with low dispersion (Abbe number less than 35) and high dispersion (Abbe number greater than 60).

[0027] Beneficial effects

[0028] First, by rationally designing the focal length of each lens group, this invention has high resolution and a large field of view, which can well simulate human eye observation and realize rapid batch testing of VR products.

[0029] Secondly, by rationally designing the focal length of each lens group, this invention enables the lens to maintain a fixed aperture and image height while simultaneously achieving a field of view similar to that of human binoculars, thus better simulating the visual experience of the human eye.

[0030] Third, by controlling the focal length ratio of each lens group in the lens, this invention helps reduce the difficulty of correcting advanced aberrations, better converges light, and improves the lens's inspection quality.

[0031] Fourth, the first lens group of this invention uses positive meniscus lenses throughout. The purpose is to capture light with a large field of view into the system while minimizing the introduction of excessive spherical aberrations. This makes it easier for subsequent lens groups to focus on correcting other aberrations.

[0032] Fifth, the second lens group of the present invention uses three positive lenses and three negative lenses, and the focal length of each lens in the lens group is designed to achieve better correction of aberrations.

[0033] Sixth, the third lens group of this invention employs two sets of cemented doublet lenses, three positive lenses, and one negative lens, which can further correct the image emitted from the second lens group.

[0034] Seventh, the field of view of the lens designed in this invention can reach 140°, which meets the requirements of high resolution and large field of view for VR inspection. It can well simulate human eye observation and realize batch rapid inspection of VR products. Attached Figure Description

[0035] Figure 1 is a schematic diagram of a lens according to a first embodiment of the present invention;

[0036] Figure 2 is a schematic diagram of a lens according to a second embodiment of the present invention;

[0037] Figure 3 is a schematic diagram of a lens according to a third embodiment of the present invention;

[0038] Figure 4 is an optical performance diagram of a lens provided according to the first embodiment of the present invention;

[0039] Figure 5 is an optical performance diagram of a lens provided according to a second embodiment of the present invention;

[0040] Figure 6 is an optical performance diagram of a lens provided according to a third embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings, but the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0042] The phrase "including..." in this specification means that, in addition to the constituent elements listed, it may also include: a single lens that does not actually have refractive power; for example, optical devices other than a single lens, such as apertures, filters and cover glass, and lens barrels, etc.

[0043] The term "...lens group" in this specification does not mean a structure that includes multiple single lenses, but can also be a structure that includes only one single lens.

[0044] This invention proposes a VR testing lens. Based on the distribution of the lenses, the lenses are sequentially divided into a first lens group, a second lens group, and a third lens group along the optical axis from the object side to the imaging surface. The testing lens also includes an aperture stop disposed between the object side and the first lens group. The aperture stop is located at the front end of the lens, which can better simulate the position of the human eye in VR glasses, thereby collecting information in the entire field of view without obstruction, and can limit the light transmission aperture of the testing lens.

[0045] A VR detection lens, comprising:

[0046] An aperture stop is used to transmit light and limit the diameter of incident light rays.

[0047] A first lens group having positive optical power is used to receive and transmit the light passing through the aperture, the first lens group comprising four positive lenses;

[0048] A second lens group with negative optical power is used to receive and transmit the light passing through the first lens group. The second lens group includes three positive lenses and three negative lenses.

[0049] A third lens group with positive optical power is used to receive and transmit the light passing through the second lens group. The third lens group includes two sets of cemented doublet lenses, three positive lenses and one negative lens.

[0050] The lens meets the following conditions:

[0051] 0.8≤|f20 / f|≤1.5, 33≤|f30 / f|≤40, 4.0≤|f40 / f|≤5.0,

[0052] Where f is the focal length of the detection lens, f20 is the focal length of the first lens group, f30 is the focal length of the second lens group, and f40 is the focal length of the third lens group.

[0053] Specifically, the four positive lenses in the first lens group are all meniscus lenses, and from the direction of the aperture stop, they are respectively the first positive lens, the second positive lens, the third positive lens, and the fourth positive lens. Among them, the first three meniscus lenses closest to the aperture stop have concave surfaces near the direction of light incidence and convex surfaces near the direction of light emission; the fourth meniscus lens has convex surfaces near the direction of light incidence and concave surfaces near the direction of light emission.

[0054] Specifically, the first lens group satisfies the following conditions:

[0055] 6.0≤|f21 / f|≤7.0, 5.0≤|f22 / f|≤6.0, 5.0≤|f23 / f|≤6.0,

[0056] 6.0≤|f²⁴ / f|≤7.0,

[0057] Where f is the focal length of the detection lens, f21 is the focal length of the first positive lens in the first lens group, f22 is the focal length of the second positive lens in the first lens group, f23 is the focal length of the third positive lens in the first lens group, and f24 is the focal length of the fourth positive lens in the first lens group.

[0058] Meniscus lenses are typically used in multi-element optical systems to modify focal length without introducing significant spherical aberration. Since the main challenge in VR inspection lens design lies in the large field of view, the first lens group's function is to reduce the beam width (approximately ±70°) to zero. To achieve this, the beam aperture needs to be increased accordingly. This increase in aperture means a simultaneous increase in aperture-related aberrations, such as spherical aberration and coma. Therefore, the first lens group is designed with a compact combination of four high-refractive-index positive meniscus lenses. The compactness is to avoid occupying excessive axial distance; a larger axial distance results in a larger aperture and a greater magnitude of aberrations that need correction. This invention uses positive meniscus lenses throughout to capture light from a large field of view into the system while minimizing the introduction of excessive spherical aberration, allowing subsequent lens groups to focus on correcting other aberrations.

[0059] Specifically, the lenses in the second lens group, from the aperture stop direction, are sequentially a first negative lens, a second negative lens, a fifth positive lens, a sixth positive lens, a seventh positive lens, and a third negative lens. The first and second negative lenses are biconcave lenses, and the third negative lens is a convex-concave lens, wherein the surface closer to the incident light direction is convex, and the surface closer to the exit light direction is concave.

[0060] Specifically, the second lens group satisfies the following conditions:

[0061] 3.5≤|f31 / f|≤4.0, 3.5≤|f32 / f|≤4.0, 6.5≤|f33 / f|≤7.5,

[0062] 5.0≤|f34 / f|≤6.0, 6.5≤|f35 / f|≤7.0, 2.5≤|f36 / f|≤3.5,

[0063] Where f is the focal length of the detection lens, f31 is the focal length of the first negative lens in the second lens group, f32 is the focal length of the second negative lens in the second lens group, f33 is the focal length of the fifth positive lens in the second lens group, f34 is the focal length of the sixth positive lens in the first lens group, f35 is the focal length of the seventh positive lens in the first lens group, and f33 is the focal length of the third negative lens in the second lens group.

[0064] Specifically, the three positive lenses and one negative lens in the third lens group are distributed on both sides of the two sets of cemented doublet lenses. One positive lens is placed on the side of the two sets of cemented doublet lenses closer to the direction of light incidence, and two positive lenses and one negative lens are placed on the side of the two sets of cemented doublet lenses closer to the direction of light emission.

[0065] Specifically, in the first lens group, the Abbe number of the first positive lens is less than 40, and the Abbe numbers of the second, third, and fourth positive lenses are greater than 50; in the second lens group, the Abbe numbers of the first to third negative lenses are all less than 30, and the Abbe numbers of the sixth to eighth positive lenses are all greater than 40; in the third lens group, both sets of cemented doublet lenses are composed of cemented glass with low dispersion (Abbe number less than 35) and high dispersion (Abbe number greater than 60).

[0066] First embodiment:

[0067] Figure 1 shows a schematic diagram of the structure of the VR detection lens in the first embodiment of this application, including an aperture stop 10, a first lens group 20 with positive optical power, a second lens group 30 with negative optical power, and a third lens group 40 with positive optical power.

[0068] The first lens group 20, having positive optical power, is used to receive and transmit the light rays passing through the aperture. The first lens group includes a first positive lens 21, a second positive lens 22, a third positive lens 23, and a fourth positive lens 24.

[0069] The second lens group 30 with negative optical power is used to receive and transmit the light passing through the first lens group. The second lens group includes a first negative lens 31, a second negative lens 32, a fifth positive lens 33, a sixth positive lens 34, a seventh positive lens 35, and a third negative lens 36.

[0070] The third lens group 40, which has positive optical power, is used to receive and transmit the light passing through the second lens group. The third lens group includes an eighth positive lens 41, a first cemented doublet lens 42, a second cemented doublet lens 43, a fourth negative lens 44, a ninth positive lens 45, and a tenth positive lens 46.

[0071] The first cemented lens 42 includes a first sub-positive lens 421 and a first sub-negative lens 422 that sequentially receive incident light rays; the first sub-positive lens is a biconvex lens and the first sub-negative lens is a biconcave lens.

[0072] The second cemented lens 43 includes a second sub-negative lens 431 and a second sub-positive lens 432 that sequentially receive incident light rays; the second sub-positive lens is a biconvex lens and the second sub-negative lens is a biconcave lens.

[0073] As a first embodiment of the present invention, the parameters of the lens shown in Figure 1 are normalized to obtain the effective focal length |f|=1mm, F-number F#=-4.83, and field of view 2ω=140°. Taking the object-side surface number of the first cemented lens in the first lens group as 1, and so on up to the image-side surface number of the tenth positive lens in the third lens group as 35. The design data of each optical element in this embodiment are shown in Table 1:

[0074] Table 1

[0075]

[0076]

[0077] Second embodiment:

[0078] Figure 2 shows a schematic diagram of the structure of the VR detection lens in the second embodiment of this application, including an aperture stop 10, a first lens group 20 with positive optical power, a second lens group 30 with negative optical power, and a third lens group 40 with positive optical power.

[0079] The first lens group 20, having positive optical power, is used to receive and transmit the light rays passing through the aperture. The first lens group includes a first positive lens 21, a second positive lens 22, a third positive lens 23, and a fourth positive lens 24.

[0080] The second lens group 30 with negative optical power is used to receive and transmit the light passing through the first lens group. The second lens group includes a first negative lens 31, a second negative lens 32, a fifth positive lens 33, a sixth positive lens 34, a seventh positive lens 35, and a third negative lens 36.

[0081] The third lens group 40, which has positive optical power, is used to receive and transmit the light passing through the second lens group. The third lens group includes an eighth positive lens 41, a first cemented doublet lens 42, a second cemented doublet lens 43, a ninth positive lens 44, a tenth positive lens 45, and a fourth negative lens 46.

[0082] The first cemented lens 42 includes a first sub-negative lens 421 and a second sub-negative lens 422 that sequentially receive incident light rays; the first sub-negative lens 421 and the second sub-negative lens 422 are plano-concave lenses and the cementing surface is a plane.

[0083] The second cemented lens 43 includes a third sub-negative lens 431 and a fourth sub-negative lens 432 that receive incident light rays in sequence; the third sub-negative lens and the fourth sub-negative lens are biconcave lenses.

[0084] As a first embodiment of the present invention, the parameters of the lens shown in Figure 2 are normalized to obtain the effective focal length |f| = 1 mm, F-number F# = -4.6786, and field of view 2ω = 140°. Taking the object-side surface number of the first cemented lens in the first lens group as 1, and so on up to the image-side surface number of the tenth positive lens in the third lens group as 35. The design data of each optical element in this embodiment are shown in Table 2.

[0085] Table 2

[0086]

[0087]

[0088] Third embodiment:

[0089] Figure 3 shows a schematic diagram of the structure of the VR detection lens in the third embodiment of this application, including an aperture stop 10, a first lens group 20 with positive optical power, a second lens group 30 with negative optical power, and a third lens group 40 with positive optical power.

[0090] The first lens group 20, having positive optical power, is used to receive and transmit the light rays passing through the aperture. The first lens group includes a first positive lens 21, a second positive lens 22, a third positive lens 23, and a fourth positive lens 24.

[0091] The second lens group 30 with negative optical power is used to receive and transmit the light passing through the first lens group. The second lens group includes a first negative lens 31, a second negative lens 32, a fifth positive lens 33, a sixth positive lens 34, a seventh positive lens 35, and a third negative lens 36.

[0092] The third lens group 40, which has positive optical power, is used to receive and transmit the light passing through the second lens group. The third lens group includes an eighth positive lens 41, a first cemented doublet lens 42, a second cemented doublet lens 43, a ninth positive lens 44, a tenth positive lens 45, and a fourth negative lens 46.

[0093] The first cemented lens 42 includes a first sub-positive lens 421 and a first sub-negative lens 422 that sequentially receive incident light rays; the first sub-positive lens is a biconvex lens and the first sub-negative lens is a biconcave lens.

[0094] The second cemented lens 43 includes a second sub-negative lens 431 and a second sub-positive lens 432 that sequentially receive incident light rays; the second sub-positive lens is a biconvex lens and the second sub-negative lens is a biconcave lens.

[0095] As a third embodiment of the present invention, the parameters of the lens shown in Figure 3 are normalized to obtain the effective focal length |f| = 1 mm, F-number F# = -4.5916, and field of view 2ω = 140°. Taking the object-side surface number of the first cemented lens in the first lens group as 1, and so on up to the image-side surface number of the tenth positive lens in the third lens group as 35. The design data of each optical element in this embodiment are shown in Table 3.

[0096] Table 3

[0097]

[0098] A specific application of the normalized lens data in one embodiment is as follows:

[0099] Assuming the image sensor used has a diagonal size of 43mm, to match the lens's imaging diameter with the sensor size, the normalized lens data from the first to third embodiments is scaled up proportionally according to the sensor size. The scaled-up aperture is approximately 3mm, located at the front of the lens, allowing for a 140° field of view, which meets the requirements of the testing lens in simulating the human eye's field of view when testing VR devices. When specifically testing VR devices, the measuring device needs to be positioned at the designated position of the human eye within the VR device to collect the same field of view seen by the user through the VR device's lens. Figures 4 to 6 show the MTF (Modulation Transfer Function) curves of the lens after scaling up the normalized data from the first to third embodiments when imaging objects at infinity. The MTF curve can evaluate the near-eye display testing lens's ability to reproduce contrast; the vertical axis represents the OTF (Optical Transfer Function) magnitude, and the horizontal axis represents the spatial frequency.

[0100] As shown in Figure 4, the MTF curve has a spatial frequency range of 0-200 lp / mm. Specifically, at a spatial frequency of 15.50 lp / mm, the OTF modulus is above 0.9; at a spatial frequency of 62.50 lp / mm, the OTF modulus is above 0.5; and at a spatial frequency of 142.60 lp / mm, the OTF modulus is above 0.2. This demonstrates that the detection lens exhibits good imaging contrast and high resolution.

[0101] As shown in Figure 5, the spatial frequency range of the MTF curve is 0-200 lp / mm. Specifically, at a spatial frequency of 16.00 lp / mm, the OTF modulus is above 0.9; at a spatial frequency of 67.00 lp / mm, the OTF modulus is above 0.5; and at a spatial frequency of 125.60 lp / mm, the OTF modulus is above 0.2. This demonstrates that the detection lens exhibits good imaging contrast and high resolution.

[0102] As shown in Figure 6, the spatial frequency range of the MTF curve is 0-200 lp / mm. Specifically, at a spatial frequency of 13.40 lp / mm, the OTF modulus is above 0.9; at a spatial frequency of 57.00 lp / mm, the OTF modulus is above 0.5; and at a spatial frequency of 111.60 lp / mm, the OTF modulus is above 0.2. This demonstrates that the detection lens exhibits good imaging contrast and high resolution.

[0103] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A VR detection lens, characterized in that, The optical axis, from the object side to the imaging plane, sequentially comprises: an aperture stop, a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power. The detection lens satisfies the following conditions: 0.8 ≤ |f20 / f| ≤ 1.5, 33 ≤ |f30 / f| ≤ 40, 4.0 ≤ |f40 / f| ≤ 5.0, where f is the focal length of the detection lens, f20 is the focal length of the first lens group, f30 is the focal length of the second lens group, and f40 is the focal length of the third lens group. The second lens group comprises three positive lenses and three negative lenses, sequentially from the aperture stop direction: first negative lens, second negative lens, fifth positive lens, sixth positive lens, seventh positive lens, and third negative lens. The first and second negative lenses are biconcave lenses, and the third negative lens is a convex-concave lens, where the surface closer to the incident light direction is convex, and the surface closer to the exit light direction is concave. The second lens group satisfies the following condition: 3.5 ≤|f31 / f|≤4.0, 3.5 ≤|f32 / f|≤4.0, 6.5≤|f33 / f|≤7.5, 5.0≤|f34 / f|≤6.0, 6.5≤|f35 / f|≤7.0, 2.5≤|f36 / f|≤3.5 where f is the focal length of the detection lens, f31 is the focal length of the first negative lens in the second lens group, f32 is the focal length of the second negative lens in the second lens group, f33 is the focal length of the fifth positive lens in the second lens group, f34 is the focal length of the sixth positive lens in the first lens group, f35 is the focal length of the seventh positive lens in the first lens group, f33... The focal length of the third negative lens in the second lens group is given. The third lens group includes two sets of cemented doublets, three positive lenses, and one negative lens. The three positive lenses and one negative lens are distributed on both sides of the two sets of cemented doublets. A positive lens is placed on the side of the two sets of cemented doublets closer to the direction of light incidence, and two positive lenses and one negative lens are placed on the side of the two sets of cemented doublets closer to the direction of light emission.

2. The VR detection lens according to claim 1, characterized in that, The first lens group includes four positive lenses; all four positive lenses in the first lens group are meniscus lenses, and from the direction of the aperture stop, they are respectively the first positive lens, the second positive lens, the third positive lens, and the fourth positive lens. Among them, the first three meniscus lenses near the aperture stop have concave surfaces near the direction of light incidence and convex surfaces near the direction of light emission; the fourth meniscus lens has convex surfaces near the direction of light incidence and concave surfaces near the direction of light emission.

3. The VR detection lens according to claim 2, characterized in that, The first lens group satisfies the following conditions: 6.0≤|f21 / f|≤7.0, 5.0≤|f22 / f|≤6.0, 5.0≤|f23 / f|≤6.0, 6.0≤|f24 / f|≤7.0, where f is the focal length of the detection lens, f21 is the focal length of the first positive lens in the first lens group, f22 is the focal length of the second positive lens in the first lens group, f23 is the focal length of the third positive lens in the first lens group, and f24 is the focal length of the fourth positive lens in the first lens group.

4. The VR detection lens according to claim 1, characterized in that, In the first lens group, the Abbe number of the first positive lens is less than 40, and the Abbe numbers of the second, third, and fourth positive lenses are greater than 50.

5. The VR detection lens according to any one of claims 1-4, characterized in that, In the second lens group, the Abbe numbers of the first to third negative lenses are all less than 30, and the Abbe numbers of the sixth to eighth positive lenses are all greater than 40.

6. The VR detection lens according to claim 5, characterized in that, In the third lens group, both sets of cemented doublet lenses are composed of cemented glass with low dispersion and high dispersion.

7. The VR detection lens according to claim 6, characterized in that, The high dispersion is defined as an Abbe number less than 35, and the low dispersion is defined as an Abbe number greater than 60.

Images