Sham lens and electronic device

Abstract

The application discloses a Sharm lens and electronic equipment, and relates to the technical field of optical systems, wherein the Sharm lens comprises a plurality of lens groups arranged in sequence from an object plane to an image plane, a plurality of the lens groups correspond to form an optical axis, the plurality of the lens groups comprise a first lens group with positive focal power, a second lens group with positive focal power, a third lens group with positive focal power, a fourth lens group with positive focal power and a fifth lens group with negative focal power; the aperture number of the Sharm lens is F, and F<3; the lens angle of the Sharm lens is alpha, and 40°<=alpha<=50°; the Sharm lens in the scheme adopts a structure of seven spherical lenses to realize a large-aperture far-object high-performance fixed-focus Sharm lens design with F# of 2.98, 45° large-inclination imaging on the object side, 100pl / mm of 0.337 MTF, average distortion of 0.1822% and a working wavelength of 470nm+ / -10nm.

Description

Technical Field

[0001] This invention relates to the field of optical system technology, and in particular to a SAM lens and electronic device. Background Technology

[0002] Scheimpflug lenses, also known as tilt-shift lenses, allow the image plane and object plane to have a certain angle according to Scheimpflug's law. They are often used in stereoscopic vision structured light photography to increase the 3D imaging range. Commercially available Scheimpflug lenses typically have a smaller working f / # (5-8) and a smaller object-side tilt angle. These lenses generally do not account for changes in magnification caused by the target defocusing.

[0003] In some special measurement scenarios, such as dynamic corneal analysis, higher sampling speeds are required, such as single-frame sampling time <0.3ms, thus requiring higher light throughput. At the same time, it is necessary to meet the requirement of low distortion so that corneal defocusing does not affect the positional relationship of the measured structure. In addition, it is also necessary to ensure that the face does not interfere with the optical path structure. In the above usage scenarios, existing SAM lenses are difficult to meet the usage requirements of light throughput, large angle, and low distortion. Summary of the Invention

[0004] The main objective of this invention is to propose a SAM lens and electronic device that aims to solve the problem that existing SAM lenses cannot simultaneously meet the requirements of light transmission, wide angle, and low distortion.

[0005] To achieve the above objectives, the present invention proposes a SAM lens, which consists of five lens groups arranged sequentially from the object plane to the image plane. The five lens groups form an optical axis corresponding to each other. The five lens groups include a first lens group with positive optical power, a second lens group with positive optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, and a fifth lens group with negative optical power.

[0006] The aperture number of the Sham lens is F, where F < 3;

[0007] The lens angle of the Sham lens is α, where 40°≤α≤50°;

[0008] The first lens group is composed of a first lens;

[0009] The second lens group consists of a second lens and a third lens;

[0010] The third lens group consists of a fourth lens and a fifth lens;

[0011] The fourth lens group is composed of the sixth lens;

[0012] The fifth lens group is composed of the seventh lens;

[0013] The first lens is a positive meniscus lens, with its object side being concave;

[0014] The second lens is a biconvex lens, and the third lens is a biconcave lens;

[0015] The fourth lens is a convex-concave lens, with its object-side surface being convex.

[0016] The fifth lens is a biconvex lens or a plano-convex lens, with its object side being a convex surface.

[0017] The sixth lens is a biconvex lens or a plano-convex lens, and its object side is either convex or flat.

[0018] The seventh lens is a concave-convex lens, with its object surface side being concave.

[0019] The second lens and the third lens are cemented doublets, and the fourth lens and the fifth lens are cemented doublets.

[0020] In one embodiment, the distance Wr between the object plane and the first lens is 75mm~80mm, and the distance Wq between the seventh lens and the image plane is 46.5mm~48.5mm.

[0021] In one embodiment, the working wavelength WL of the SAM lens is 460nm~480nm, the working magnification β of the SAM lens is 0.8~1, and the imaging distortion of the SAM lens is less than 0.2%.

[0022] In one embodiment, the SAM lens further includes an aperture stop disposed between the third lens and the fourth lens, and the pupil diameter of the SAM lens is Ds, where Ds > 19 mm.

[0023] In one embodiment, the refractive index and Abbe number of the second lens are greater than those of the third lens, and the refractive index and Abbe number of the fourth lens are less than those of the fifth lens; and / or,

[0024] The second lens and the third lens are made of different glass materials; and / or,

[0025] The fourth lens and the fifth lens are made of different glass materials.

[0026] In one embodiment, the curvature of the object plane side and the image plane side of the second lens are equal.

[0027] The present invention also proposes an electronic device, the electronic device including a SAM lens, the SAM lens including a plurality of lens groups arranged sequentially from the object plane to the image plane, the plurality of lens groups correspondingly forming an optical axis, the plurality of lens groups including a first lens group with positive optical power, a second lens group with positive optical power, a third lens group with positive optical power, a fourth lens group with positive optical power and a fifth lens group with negative optical power;

[0028] The aperture number of the Sham lens is F, where F < 3;

[0029] The lens angle of the Sham lens is α, where 40°≤α≤50°.

[0030] The technical solution of this invention, through the use of the fixed-focus lens provided in the embodiments of this invention, employs a 7-spherical lens structure to achieve a high-performance fixed-focus SAM lens design with a large aperture and far object-side distance, an F# of 2.98, an object-side tilt angle of 45°, a 100pl / mm MTF of 0.337, an average distortion of 0.1822%, and an operating wavelength of 470nm±10nm. This effectively meets the needs of some special measurement scenarios, such as dynamic corneal analysis, and overcomes some problems existing in current SAM lenses, demonstrating promising application prospects. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0032] Figure 1 A schematic diagram of the lens structure layout of the Sham lens provided for this solution;

[0033] Figure 2 for Figure 1 The diagram provided shows the MTF curve of the Sham lens on the image plane.

[0034] Figure 3 for Figure 1 A schematic diagram of another embodiment of the Sham lens provided in the diagram.

[0035] Explanation of icon numbers:

[0036] 100. Schahm lens; 1. First lens group; 11. First lens; 2. Second lens group; 21. Second lens; 22. Third lens; 3. Third lens group; 31. Fourth lens; 32. Fifth lens; 4. Fourth lens group; 41. Sixth lens; 5. Fifth lens group; 51. Seventh lens; 6. Object plane; 7. Image plane; 8. Aperture.

[0037] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. 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 if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0040] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0041] Schemimpflug lenses, also known as tilt-shift lenses, allow the image plane and object plane to have a certain angle according to Schemimpflug's law. They are often used in stereoscopic vision structured light photography to increase the 3D imaging range. Commercially available Schemimpflug lenses generally have a small working f / # (5-8) and a small object-side tilt angle. These lenses generally do not account for changes in magnification caused by the target defocusing.

[0042] In some special measurement scenarios, such as dynamic corneal analysis, higher sampling speeds are required, such as single-frame sampling time <0.3ms, thus requiring higher light throughput. At the same time, it is necessary to meet the requirement of low distortion so that corneal defocusing does not affect the positional relationship of the measured structure. In addition, it is also necessary to ensure that the face does not interfere with the optical path structure. In the above usage scenarios, existing SAM lenses are difficult to meet the usage requirements of light throughput, large angle, and low distortion.

[0043] This invention proposes a Sham lens 100 to solve the above problems.

[0044] Please see Figures 1 to 3 The Scharm lens, also known as a tilt-shift lens, allows the image plane and object plane to have a certain angle according to Scharm's law. When the extensions of the target plane, the lens principal plane, and the imaging plane intersect on a single line, a clear image can be captured of the entire tilted target's field of view. Therefore, it is often used in stereoscopic vision structured light photography to increase the 3D imaging range. However, in some special measurement scenarios, such as in corneal dynamic analysis, traditional Scharm lenses struggle to simultaneously meet the requirements of light transmission, large angle, and low distortion. This embodiment aims to address these issues. A SAM lens 100 is proposed, comprising a first lens group 1 with positive optical power, a second lens group 2 with positive optical power, a third lens group 3 with positive optical power, a fourth lens group 4 with positive optical power, and a fifth lens group 5 with negative optical power, arranged sequentially from the object plane 6 to the image plane 7. The fifth lens group 5 is used to adjust the distance between the lens and the CCD and the image height. The multiple lens groups have the same optical axis. The arrangement of the lens group structure enables the SAM lens 100 to achieve wide-angle imaging and simultaneously provides the SAM lens 100 with a suitable working distance, resulting in a significant improvement effect. Specifically, the working distance Wd of the SAM lens 100 is 70mm~90mm; the lens angle α can reach a range of 45°±5°; in use, its aperture F can reach 2.4, which has good light transmission. During corneal dynamic analysis, the single-frame sampling time is less than 0.3ms. The light transmission in this embodiment can well meet the requirements. At the same time, the working distance is long enough to effectively avoid interference between the face and the optical path structure, thus affecting the image quality. Furthermore, its lens angle can reach 50°, which is wider than that of traditional SAM lenses in terms of 3D imaging range. Moreover, during corneal dynamic analysis, it can acquire as much specific 3D image information as possible from both sides of the cornea, providing sufficient information support for subsequent analysis.

[0045] Specifically, the lens groups comprise the following specific lens compositions: the first lens group 1 includes a first lens 11; the second lens group 2 includes a second lens 21 and a third lens 22; the third lens group 3 includes a fourth lens 31 and a fifth lens 32; the fourth lens group 4 includes a sixth lens 41; and the fifth lens group 5 includes a seventh lens 51. The Sham lens 100 is composed of seven lens structures, and these seven lenses are arranged sequentially from the object plane 6 to the image plane 7, together constituting the main imaging structure of the Sham lens 100.

[0046] The focal length of the first lens group 1 is 160mm; the focal length of the second lens group 2 is 374mm; the focal length of the third lens group 3 is 91mm; the focal length of the fourth lens group 4 is 109mm; and the focal length of the fifth lens group 5 is -171mm.

[0047] Furthermore, the specific surface configurations of the aforementioned lenses in the Sham lens 100 are as follows:

[0048] The first lens 11 is a positive meniscus lens with a concave surface on its object plane 6 side; the second lens 21 is a biconvex lens, preferably configured such that the curvature of the object plane 6 side and the image plane 7 side are equal; the third lens 22 is a biconcave lens; the fourth lens 31 is a convex-concave lens with a convex surface on its object plane; the fifth lens 32 is a biconvex lens or a plano-convex lens with a convex surface on its object plane 6 side; the sixth lens 41 is a biconvex lens or a plano-convex lens, with its object plane 6 side correspondingly being convex or planar; and the seventh lens 51 is a concave-convex lens with a concave surface on its object plane 6 side. The seventh lens 51 is a concave-convex lens with negative optical power, primarily used to adjust the distance between the lens and the CCD and the image height.

[0049] The distance Wr between the object plane 6 and the first lens 11 is 75mm~80mm, and the distance Wq between the seventh lens 51 and the image plane 7 is 46.5mm~48.5mm, which can compensate for assembly errors during the lens structure installation process. The specific settings of the first lens 11 and the seventh lens 51, combined with the specific focal length designs of the first lens 11 to the seventh lens 51, enable the entire SAM lens 100 to form a telecentric object-side structure. Even with a large object-side tilt angle, the magnification of the image can remain relatively stable when accurate focusing is not possible. This avoids the magnification changes caused by the small light transmission and object-side tilt angle of traditional SAM lenses after the target defocuses. If the magnification changes, the corresponding actual measurement data will be affected, impacting the accuracy of the measurement data. Using the above structure in this embodiment, the distortion of the SAM lens 100 can be controlled below 0.2%.

[0050] The operating wavelength WL of the Sham lens 100 is 460nm~480nm.

[0051] In order to ensure that the entire SAM lens 100 has a large light-transmitting aperture, in this embodiment, the pupil diameter is greater than 19mm.

[0052] The second lens 21 and the third lens 22 are cemented doublet lenses, and the fourth lens 31 and the fifth lens 32 are also cemented doublet lenses. However, the second lens 21 and the third lens 22 are made of different glass materials, and the fourth lens 31 and the fifth lens 32 are also made of different glass materials.

[0053] The refractive index and Abbe number of the second lens 21 are greater than those of the third lens 22, and the refractive index and Abbe number of the fourth lens 31 are less than those of the fifth lens 32. For specific details, please refer to Table 1 below.

[0054] The design parameters of each lens in the Sham lens 100 are as follows:

[0055] Table 1

[0056]

[0057] The SAM lens 100 described in this solution employs a 7-spherical lens structure to achieve a high-performance fixed-focus SAM lens design with a large aperture and far object-side distance, an F# of 2.98, a 45° object-side tilt imaging angle, a 100pl / mm resolution of 0.337 MTF, an average distortion of 0.1822%, and an operating wavelength of 470nm±10nm. It effectively meets the needs of some special measurement scenarios, such as dynamic corneal analysis, and overcomes some of the problems existing in current SAM lenses, demonstrating promising application prospects.

[0058] In another embodiment, the Sham lens 100, in addition to the above-described embodiments, also has another structural embodiment, such as... Figure 3 As shown, inserting a reflective mirror between the first lens 11 and the second lens 21 can fold the optical path, shortening the total length of the optical path, or shortening the distance between the first lens 11 and the second lens 21 to shorten the total length of the optical path.

[0059] The present invention also proposes an electronic device, which includes a SAM lens 100. The specific structure of the SAM lens 100 is as described in the above embodiments. Since the electronic device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0060] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A Sham lens, characterized in that, The SAM lens consists of five lens groups arranged sequentially from the object plane to the image plane, with the five lens groups corresponding to each other to form an optical axis. The five lens groups include a first lens group with positive optical power, a second lens group with positive optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, and a fifth lens group with negative optical power. The aperture number of the Sham lens is F, where F < 3; The lens angle of the Sham lens is α, where 40°≤α≤50°; The first lens group is composed of a first lens; The second lens group consists of a second lens and a third lens; The third lens group consists of a fourth lens and a fifth lens; The fourth lens group is composed of the sixth lens; The fifth lens group is composed of the seventh lens; The first lens is a positive meniscus lens, with its object side being concave; The second lens is a biconvex lens, and the third lens is a biconcave lens; The fourth lens is a convex-concave lens, with its object-side surface being convex. The fifth lens is a biconvex lens or a plano-convex lens, with its object side being a convex surface. The sixth lens is a biconvex lens or a plano-convex lens, and its object side is either convex or flat. The seventh lens is a concave-convex lens, with its object surface side being concave. The second lens and the third lens are cemented doublets, and the fourth lens and the fifth lens are cemented doublets.

2. The Sham lens as described in claim 1, characterized in that, The distance Wr between the object plane and the first lens is 75mm~80mm, and the distance Wq between the seventh lens and the image plane is 46.5mm~48.5mm.

3. The Sham lens as described in claim 1, characterized in that, The working wavelength WL of the SAM lens is 460nm~480nm, the working magnification β of the SAM lens is 0.8~1, and the imaging distortion of the SAM lens is less than 0.2%.

4. The Sham lens as described in claim 1, characterized in that, The SAM lens also includes an aperture stop, which is located between the third lens and the fourth lens, and the pupil diameter of the SAM lens is Ds, where Ds > 19 mm.

5. The Sham lens as described in claim 1, characterized in that, The refractive index and Abbe number of the second lens are greater than those of the third lens, and the refractive index and Abbe number of the fourth lens are less than those of the fifth lens; and / or, The second lens and the third lens are made of different glass materials; and / or, The fourth lens and the fifth lens are made of different glass materials.

6. The Sham lens as described in claim 1, characterized in that, The curvature of the object plane side and the image plane side of the second lens are equal.

7. An electronic device, characterized in that, Includes the Sham lens as described in any one of claims 1-6.

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