Wide-angle optical system and optical apparatus

Abstract

The utility model discloses a wide-angle optical system and optical equipment, and relates to the technical field of optics. The first lens comprises a first mirror surface and a second mirror surface, the first mirror surface is a convex surface, and the second mirror surface is a concave surface; the second lens comprises a third mirror surface and a fourth mirror surface, and the third mirror surface and the fourth mirror surface are convex surfaces; the third lens comprises a fifth mirror surface and a sixth mirror surface, and the fifth mirror surface and the sixth mirror surface are convex surfaces; the fourth lens comprises a seventh mirror surface and an eighth mirror surface, the seventh mirror surface is a concave surface, and the eighth mirror surface is a convex surface; the photoelectric sensor is arranged on one side of the eighth mirror surface, the view field angle of the lens is 180-200 degrees, the relative aperture is 2.0-2.8, the diameter of a defocused spot is smaller than 4 microns, and the relative light transmission is larger than 50%. According to the technical scheme of the utility model, only four lenses are adopted, so that the overall size of the lens is greatly reduced; the number of the lenses is reduced, spherical aberration, coma, astigmatism, chromatic aberration and the like can be effectively corrected, the debugging difficulty is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of optics, and particularly relates to a wide-angle optical system and an optical device. Background Art

[0002] At present, most photographic objectives use the Cooke three-piece type and its improved structures. In the improved models of ultra-wide-angle lenses, usually at least six lenses are used in the lens structure. The structural design is complex, the volume is large, the debugging difficulty is great in terms of spherical aberration, coma, astigmatism, chromatic aberration, etc., and the cost is relatively high. Therefore, the price of ultra-wide-angle lenses on the market remains high. Content of the Utility Model

[0003] The main purpose of the utility model is to provide a wide-angle optical system and an optical device, aiming to solve the technical problems in the prior art that the wide-angle lens has many lenses, a complex structure, great debugging difficulty and high cost.

[0004] To achieve the above object, the utility model provides a wide-angle optical system, which includes a lens and a photoelectric sensor. The lens includes the following lenses arranged in sequence:

[0005] A first lens, which includes a first mirror surface and a second mirror surface. The first mirror surface is a convex surface, and the second mirror surface is a concave surface;

[0006] A second lens, which includes a third mirror surface and a fourth mirror surface. Both the third mirror surface and the fourth mirror surface are convex surfaces;

[0007] A third lens, which includes a fifth mirror surface and a sixth mirror surface. Both the fifth mirror surface and the sixth mirror surface are convex surfaces;

[0008] A fourth lens, which includes a seventh mirror surface and an eighth mirror surface. The seventh mirror surface is a concave surface, and the eighth mirror surface is a convex surface;

[0009] The photoelectric sensor is arranged on one side of the eighth mirror surface. A light beam enters the first lens from the first mirror surface and sequentially passes through the second mirror surface, the third mirror surface, the fourth mirror surface, the fifth mirror surface, the sixth mirror surface, the seventh mirror surface, and the eighth mirror surface until it is incident on the photoelectric sensor;

[0010] Among them, the first lens is a negative lens, the second lens is a positive lens, the third lens is a positive lens, and the fourth lens is a negative lens; the field angle of the lens is 200 degrees, the relative aperture is 2.4 - 2.8, the diameter of the blur spot is less than 4um, and the relative light transmission is greater than 50%.

[0011] In one embodiment, the aperture of the first mirror is 8 mm to 10 mm, the aperture of the second mirror is 4 mm to 6 mm, the aperture of the third mirror is 2 mm to 4 mm, the aperture of the fourth mirror is 2 mm to 4 m, the aperture of the fifth mirror is 3 mm to 5 m, the aperture of the sixth mirror is 3 mm to 5 m, the aperture of the seventh mirror is 3 mm to 5 m, and the aperture of the eighth mirror is 3 mm to 5 m.

[0012] In one embodiment, the radius of curvature of the first mirror is 19 to 20, the radius of curvature of the second mirror is 2.2 to 2.6, the radius of curvature of the third mirror is 7.2 to 8, the radius of curvature of the fourth mirror is 7.2 to 8, the radius of curvature of the fifth mirror is 5.2 to 5.8, the radius of curvature of the sixth mirror is 2.2 to 2.8, the radius of curvature of the seventh mirror is 2.2 to 2.8, and the eighth mirror is a plane.

[0013] In one embodiment, the thickness of the first lens is 0.5 mm to 0.7 mm, the distance between the second mirror and the third mirror is 5 mm to 6 mm, the thickness of the second lens is 3.8 mm to 4.5 mm, the distance between the fourth mirror and the fifth mirror is 0.02 mm to 0.15 mm, the thickness of the third lens is 2.2 mm to 2.8 mm, and the thickness of the fourth lens is 0.4 mm to 0.6 mm;

[0014] Wherein the convex shape of the sixth mirror is adapted to the concave shape of the seventh mirror, and the sixth mirror and the seventh mirror are arranged in a fitting manner.

[0015] In one embodiment, the refractive index of the first lens is 1.74 to 1.8, the refractive index of the second lens is 1.74 to 1.8, the refractive index of the third lens is 1.68 to 1.72, and the refractive index of the fourth lens is 1.82 to 1.86;

[0016] The dispersion coefficient of the first lens is 46 to 52, the dispersion coefficient of the second lens is 46 to 52, the dispersion coefficient of the third lens is 53 to 57, and the dispersion coefficient of the fourth lens is 22 to 25.

[0017] In one embodiment, the Abbe numbers of the first lens, the second lens, the third lens, and the fourth lens are greater than 60.

[0018] In one embodiment, the wide-angle optical system further includes a protective sheet, the protective sheet is disposed on a side of the first lens away from the second lens, and the imaging band of the protective sheet is 400 nm to 1100 nm.

[0019] In one embodiment, the wide-angle optical system further includes a housing having an accommodation cavity therein, and the photoelectric sensor, the first lens, the second lens, the third lens, and the fourth lens are all disposed in the accommodation cavity;

[0020] The optical axes of the first lens, the second lens, the third lens, and the fourth lens are overlapped.

[0021] In one embodiment, the wide-angle optical system further includes a rotating member connected to the housing, and the rotating member is configured to drive the lens and the photoelectric sensor to rotate synchronously.

[0022] In addition, to solve the above problems, the present utility model further provides an optical device, on which the above wide-angle optical system is mounted.

[0023] The lens in the technical solution of the present utility model is only composed of four lenses, greatly reducing the overall volume of the lens; and the field angle of the lens is 180 degrees to 200 degrees, the relative aperture is 2.0 to 2.8, the diameter of the circle of confusion is less than 4um, and the relative light transmission is greater than 50%; by reducing the number of lenses, it is also possible to effectively correct spherical aberration, coma, astigmatism, chromatic aberration, etc., reducing the debugging difficulty and the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of an embodiment of the subject matter provided by the present utility model;

[0026] Figure 2 is Figure 1 the MTF curve graph of the camera objective optical system in;

[0027] Figure 3 is Figure 1 the spot diagram of the camera objective optical system in;

[0028] Figure 4 is Figure 1 the ray aberration graph of the camera objective optical system in;

[0029] Figure 5 is Figure 1 the left field curvature graph and the right distortion graph of the camera objective optical system in;

[0030] Figure 6 For Figure 1 the relative illumination diagram of the camera objective optical system in

[0031] Explanation of the reference numerals in the attached drawings:

[0032]

[0033]

[0034] The realization, functional features and advantages of the purpose of the present utility model will be further described in conjunction with the embodiments and with reference to the attached drawings. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the attached drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0036] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood 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, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes the A solution, or the B solution, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot 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 utility model.

[0038] The utility model discloses a wide-angle optical system and an optical device. The wide-angle optical system includes a lens and a photoelectric sensor 50. The lens includes a first lens 10, a second lens 20, a third lens 30, and a fourth lens 40 arranged in sequence. The first lens 10 includes a first mirror surface 11 and a second mirror surface 12. The first mirror surface 11 is a convex surface, and the second mirror surface 12 is a concave surface. The second lens 20 includes a third mirror surface 21 and a fourth mirror surface 22. Both the third mirror surface 21 and the fourth mirror surface 22 are convex surfaces. The third lens 30 includes a fifth mirror surface 31 and a sixth mirror surface 32. Both the fifth mirror surface 31 and the sixth mirror surface 32 are convex surfaces. The fourth lens 40 includes a seventh mirror surface 41 and an eighth mirror surface 42. The seventh mirror surface 41 is a concave surface, and the eighth mirror surface 42 is a convex surface.

[0039] The photoelectric sensor 50 is arranged on one side of the eighth mirror surface 42. A light beam enters the first lens 10 from the first mirror surface 11 and sequentially passes through the second mirror surface 12, the third mirror surface 21, the fourth mirror surface 22, the fifth mirror surface 31, the sixth mirror surface 32, the seventh mirror surface 41, and the eighth mirror surface 42 until it is incident on the photoelectric sensor 50.

[0040] Wherein, the field angle of the lens is 180 degrees to 200 degrees, the relative aperture is 2.0 to 2.8, the diameter of the circle of confusion is less than 4um, and the relative light transmission is greater than 50%.

[0041] In one embodiment, a total of four lenses are provided to achieve ultra-wide-angle shooting, and the structure is simple. The first lens 10 is an objective lens. Please refer to Figure 1 , on the left side of the first lens 10 is the first mirror surface 11, the first mirror surface 11 faces the object side, and from left to right are the second mirror surface 12, the third mirror surface 21... the eighth mirror surface 42.

[0042] The light beam on the object side sequentially passes through the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 to reach the optical sensor, thereby forming an image on the optical sensor.

[0043] The first mirror surface 11 is a convex surface protruding to the left, the second mirror surface 12 is a concave surface concave to the left, the third mirror surface 21 is a convex surface protruding to the left, the fourth mirror surface 22 is a convex surface protruding to the right, the fifth mirror surface 31 is a convex surface protruding to the left, the sixth mirror surface 32 is a convex surface protruding to the right, the seventh mirror surface 41 is a concave surface concave to the right, and the eighth mirror surface 42 is a convex surface protruding to the right.

[0044] Both the second lens 20 and the third lens 30 use double-sided convex lenses to cause large-angle deflection of light, thereby shortening the focusing position of the light. The eighth mirror surface 42 also uses a convex surface to converge the light beam, further adjusting the light beam propagation path to ensure clear imaging on the image side.

[0045] The first lens 10 is a negative lens, the second lens 20 is a positive lens, the third lens 30 is a positive lens, and the fourth lens 40 is a negative lens, which corrects spherical aberration, coma, astigmatism, chromatic aberration, etc. The effective field of view angle reaches ±100 degrees, and the image quality is good within ±100 degrees. Please refer to Figures 2 to 6 , which is the simulation effect of imaging parameters in this embodiment.

[0046] The lens in the technical solution of the utility model is composed of only four lenses, which greatly reduces the overall size of the lens; and the field of view angle of the lens is 200 degrees, the relative aperture is 2.4-2.8, the diameter of the diffuse spot is less than 4um, and the relative light transmittance is greater than 50%; by reducing the number of lenses, spherical aberration, coma, astigmatism, chromatic aberration, etc. can be effectively corrected, reducing the difficulty of debugging and reducing production costs.

[0047] In one embodiment, the aperture of the first mirror 11 is 8mm-10mm, the aperture of the second mirror 12 is 4mm-6mm, the aperture of the third mirror 21 is 2mm-4mm, the aperture of the fourth mirror 22 is 2mm-4mm, the aperture of the fifth mirror 31 is 3mm-5mm, the aperture of the sixth mirror 32 is 3mm-5mm, the aperture of the seventh mirror 41 is 3mm-5mm, and the aperture of the eighth mirror 42 is 3mm-5mm.

[0048] In this embodiment, the apertures of the first mirror 11 to the eighth mirror 42 are preferably set to 8.4mm, 4.8mm, 2.2mm, 3.2mm, 3.4mm, 3.4mm, 3.6mm, and 3.8mm, respectively. The overall size of the lens is greatly reduced, which is suitable for mass production and low cost. Moreover, the above-mentioned parameter assembly can also correct spherical aberration, coma, astigmatism, chromatic aberration, etc., and can present better image quality within ±100 degrees.

[0049] In one embodiment, the radius of curvature of the first mirror surface 11 is 19 to 20, the radius of curvature of the second mirror surface 12 is 2.2 to 2.6, the radius of curvature of the third mirror surface 21 is 7.2 to 8, the radius of curvature of the fourth mirror surface 22 is 7.2 to 8, the radius of curvature of the fifth mirror surface 31 is 5.2 to 5.8, the radius of curvature of the sixth mirror surface 32 is 2.2 to 2.8, the radius of curvature of the seventh mirror surface 41 is 2.2 to 2.8, and the eighth mirror surface 42 is a plane.

[0050] It should be noted that the surface of the first mirror surface 11 is relatively flat, so it does not affect the installation of a protective sheet or the like in front of the first mirror surface 11 .

[0051] In one embodiment, the wide-angle optical system further includes a protective sheet, which is disposed on the side of the first lens 10 away from the second lens 20, and the imaging band of the protective sheet is 450nm to 1100nm.

[0052] In one embodiment, please refer to Figure 1 , the thickness of the first lens 10 is 0.5mm to 0.7mm, the distance between the second mirror surface 12 and the third mirror surface 21 is 5mm to 6mm, the thickness of the second lens 20 is 3.8mm to 4.5mm, the distance between the fourth mirror surface 22 and the fifth mirror surface 31 is 0.02mm to 0.15mm, the thickness of the third lens 30 is 2.2mm to 2.8mm, and the thickness of the fourth lens 40 is 0.4mm to 0.6mm; wherein the convex shape of the sixth mirror surface 32 is adapted to the concave shape of the seventh mirror surface 41, and the sixth mirror surface 32 and the seventh mirror surface 41 are disposed in contact with each other.

[0053] Wherein, the thickness of the lens refers to the wall thickness of the lens at its optical axis or central axis position.

[0054] Preferably in this embodiment, the thickness of the first lens 10 is 0.6mm, the distance between the second mirror surface 12 and the third mirror surface 21 is 5.8mm, the thickness of the second lens 20 is 4.1mm, the distance between the fourth mirror surface 22 and the fifth mirror surface 31 is 0.1mm, the thickness of the third lens 3030 is 2.3mm, the sixth mirror surface 32 and the seventh mirror surface 41 are in contact, and the thickness of the fourth lens 4040 is 0.5mm.

[0055] In one embodiment, the refractive index of the first lens 10 is 1.74 to 1.8, the refractive index of the second lens 20 is 1.74 to 1.8, the refractive index of the third lens 30 is 1.68 to 1.72, and the refractive index of the fourth lens 40 is 1.82 to 1.86; the dispersion coefficient of the first lens 10 is 46 to 52, the dispersion coefficient of the second lens 20 is 46 to 52, the dispersion coefficient of the third lens 30 is 53 to 57, and the dispersion coefficient of the fourth lens 40 is 22 to 25.

[0056] By using the material characteristics, the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 are prepared into high-refractive-index lenses, and the dispersion coefficient of the lenses is controlled to realize high-Abbe-number and high-refractive-index lenses. The Abbe numbers of the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 are greater than 60.

[0057] In one embodiment, the wide-angle optical system further includes a housing having an accommodation cavity therein, and the photoelectric sensor 50, the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 are all disposed in the accommodation cavity; the optical axes of the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 are overlapped.

[0058] The first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 are fixed in the housing, and through the limiting function of the housing, the optical axes of the first lens 10, the second lens 20, the third lens 30, and the fourth lens 40 are kept on the same straight line, preventing the light beam from shifting when passing through different lenses, which may cause unclear imaging.

[0059] In this embodiment, in order to further improve the usability and wide adaptability, an adjustment block may be provided on the housing, and the position of the adjustment block corresponds to the position of the lens. Each of the first lens 10 to the fourth lens 40 is provided with an adjustment block. By pressing the adjustment block, the position of the lens in the housing can be adjusted, and the optical axis position of the lens can be adjusted.

[0060] In one embodiment, the wide-angle optical system further includes a rotating member connected to the housing, and the rotating member is used to drive the lens and the photoelectric sensor 50 to rotate synchronously.

[0061] The rotating member can be connected to the housing in a gear rotation manner. When in use, the housing can be fixed, and the housing is rotated through the rotating member to adjust the imaging position to ensure that the first lens 10 is aligned with the object side. It is suitable for installation spaces with relatively small spaces, such as cat's eyes on security doors, or devices such as laptops.

[0062] In addition, to solve the above problems, the present invention also proposes an optical device, and the above wide-angle optical system is mounted on the optical device. The optical system can be, for example, a camera, a camera head, a lens group, etc.

[0063] It is composed of four lenses, which greatly reduces the overall volume of the optical device, is suitable for mass production, and has a low cost. And through the above parameter assembly, spherical aberration, coma, astigmatism, chromatic aberration, etc. can also be corrected, and better image quality can be presented within ±90 degrees. Therefore, the structure of the present invention is relatively small and can be applied to devices such as cat's eyes on security doors or home monitoring.

[0064] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A wide-angle optical system, characterized in that, The wide-angle optical system includes a lens and a photoelectric sensor. The lens includes the following lenses arranged in sequence: The first lens, which includes a first mirror surface and a second mirror surface. The first mirror surface is a convex surface, and the second mirror surface is a concave surface. The second lens, which includes a third mirror surface and a fourth mirror surface. Both the third mirror surface and the fourth mirror surface are convex surfaces. The third lens, which includes a fifth mirror surface and a sixth mirror surface. Both the fifth mirror surface and the sixth mirror surface are convex surfaces. The fourth lens, which includes a seventh mirror surface and an eighth mirror surface. The seventh mirror surface is a concave surface, and the eighth mirror surface is a convex surface. The photoelectric sensor is arranged on one side of the eighth mirror surface. The light beam enters the first lens from the first mirror surface and sequentially passes through the second mirror surface, the third mirror surface, the fourth mirror surface, the fifth mirror surface, the sixth mirror surface, the seventh mirror surface, and the eighth mirror surface until it is incident on the photoelectric sensor. Among them, the first lens is a negative lens, the second lens is a positive lens, the third lens is a positive lens, and the fourth lens is a negative lens. The field angle of the lens is 180 degrees to 200 degrees, the relative aperture is 2.0 to 2.8, the diameter of the circle of confusion is less than 4um, and the relative light transmission is greater than 50%.

2. The wide-angle optical system according to claim 1, characterized in that, The aperture of the first mirror surface is 8mm to 10mm, the aperture of the second mirror surface is 4mm to 6mm, the aperture of the third mirror surface is 2mm to 4mm, the aperture of the fourth mirror surface is 2mm to 4m, the aperture of the fifth mirror surface is 3mm to 5m, the aperture of the sixth mirror surface is 3mm to 5m, the aperture of the seventh mirror surface is 3mm to 5m, and the aperture of the eighth mirror surface is 3mm to 5m.

3. The wide-angle optical system according to claim 1, characterized in that The radius of curvature of the first mirror surface is 19 to 20, the radius of curvature of the second mirror surface is 2.2 to 2.6, the radius of curvature of the third mirror surface is 7.2 to 8, the radius of curvature of the fourth mirror surface is 7.2 to 8, the radius of curvature of the fifth mirror surface is 5.2 to 5.8, the radius of curvature of the sixth mirror surface is 2.2 to 2.8, the radius of curvature of the seventh mirror surface is 2.2 to 2.8, and the eighth mirror surface is a plane.

4. The wide-angle optical system according to claim 3, wherein The thickness of the first lens is 0.5mm to 0.7mm, the distance between the second mirror surface and the third mirror surface is 5mm to 6mm, the thickness of the second lens is 3.8mm to 4.5mm, the distance between the fourth mirror surface and the fifth mirror surface is 0.02mm to 0.15mm, the thickness of the third lens is 2.2mm to 2.8mm, and the thickness of the fourth lens is 0.4mm to 0.6mm. Among them, the convex shape of the sixth mirror surface is adapted to the concave shape of the seventh mirror surface, and the sixth mirror surface and the seventh mirror surface are arranged in a fitting manner.

5. The wide-angle optical system according to claim 1, characterized in that, The refractive index of the first lens is 1.74 to 1.8, the refractive index of the second lens is 1.74 to 1.8, the refractive index of the third lens is 1.68 to 1.72, and the refractive index of the fourth lens is 1.82 to 1.

86. The dispersion coefficient of the first lens is 46 to 52, the dispersion coefficient of the second lens is 46 to 52, the dispersion coefficient of the third lens is 53 to 57, and the dispersion coefficient of the fourth lens is 22 to 25.

6. The wide-angle optical system according to claim 1, wherein The Abbe numbers of the first lens, the second lens, the third lens, and the fourth lens are greater than 60.

7. The wide-angle optical system according to claim 1, wherein The wide-angle optical system further includes a protective sheet, which is disposed on a side of the first lens away from the second lens, and the imaging wavelength band of the protective sheet is 400 nm to 1100 nm.

8. The wide-angle optical system according to claim 1, characterized in that, The wide-angle optical system further includes a housing having an accommodation cavity therein, and the photoelectric sensor, the first lens, the second lens, the third lens, and the fourth lens are all disposed in the accommodation cavity; The optical axes of the first lens, the second lens, the third lens, and the fourth lens are overlapped.

9. The wide-angle optical system according to claim 8, wherein, The wide-angle optical system further includes a rotating member connected to the housing, and the rotating member is configured to drive the lens and the photoelectric sensor to rotate synchronously.

10. An optical device, characterized in that, The optical device is equipped with the wide-angle optical system according to any one of claims 1 to 9.

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