3D fisheye lens and camera and video camera using same

Abstract

The utility model relates to a 3D fisheye lens and camera and video camera applying the same, the 3D fisheye lens comprises a first lens group G1 with positive diopter, an aperture stop and a second lens group G2 with positive diopter from an object side to an image plane side in sequence, the first lens group G1 is divided into two parts, the object side is a front part G1a with negative diopter, the image plane side is a rear part G1b with positive diopter, and the second lens group G2 is a rear part G1b with negative diopter. Wherein the G1a of the front part is composed of three continuous negative lenses, and the G1b of the rear part is a biconvex double-sided aspheric surface. The fisheye lens provided by the utility model has the advantages of miniaturization, high performance, large image field, a field angle of more than 200 degrees, enough gentle curvature radius of the first glass, enough small mutual shielding, enough small effective aperture, and capability of simulating the visual effect of eyes.

Description

Technical Field

[0001] This invention relates to a full-circle fisheye lens with a field of view exceeding 190 degrees, which can be widely used in digital camera lenses, camcorder lenses, drone cameras, and especially in the field of shooting 3D scenes. Background Technology

[0002] Currently, many fisheye lenses with a field of view exceeding 180 degrees are publicly known. However, for VR applications requiring stitching, a field of view exceeding 180 degrees is necessary, ideally exceeding 190 degrees. Furthermore, when shooting 3D effects, it's crucial to mimic human vision. The ideal distance between the two fisheye lenses is close to the distance between the pupils of the human eye. The interpupillary distance is typically between 50-70mm, with an average of 60-65mm being the most accurate. For 8K ultra-high definition, covering the full-frame (24mm×36mm) inscribed circular image field, the fisheye lens needs to be sufficiently small, with an image field diameter close to 24mm, and a wide field of view. To meet the requirements, the field of view must be greater than 190 degrees. In addition, during 3D shooting, the two lenses placed side by side should not block each other as much as possible. This requires that the curvature radius of the first lens be sufficiently gentle. However, it is almost impossible to find a fisheye lens that simultaneously meets the requirements of a field of view of more than 190 degrees, a small size, high performance, and a large image field. For example, although the image field of the Japanese Patent Application Publication No. 2004-258515 is large enough, the outer diameter of the front glass is too large. If two fisheye lenses are placed side by side, the diameter will be much greater than 70mm, which does not conform to the distance between the pupils of the human eye. At the same time, the field of view is only 180 degrees, and the effect of application will be very unsatisfactory.

[0003] There is also the well-known Japanese Patent Application Publication No. 2016-184136. Although the image field size is suitable and the field of view exceeds 190 degrees, approaching 200 degrees, the outer diameter of the first glass is too large, and the radius of curvature is too strong. With this side-by-side arrangement, the optical axis distance between the two lenses will be greater than 70mm, exceeding the interpupillary distance of the human eye. At the same time, because the radius of curvature of the first glass is less than 50mm, it will be very abrupt, and the mutual obstruction of vision will be very serious. Therefore, the effect of using it for 3D shooting is not ideal, and there are still many problems. Utility Model Content

[0004] In order to overcome the problems of the aforementioned fisheye lenses, which cannot achieve miniaturization, a large image field, a field of view exceeding 190 degrees, and a sufficiently gentle curvature radius of the first glass element, this utility model will provide a miniaturized, high-performance fisheye lens with a large image field, a field of view exceeding 190 degrees, and a sufficiently gentle curvature radius of the first glass element.

[0005] To achieve the above objectives, the technical solution of this utility model is: a 3D fisheye lens, which, from the object side to the image plane side, sequentially includes a first lens group G1 with positive refractive power and a second lens group G2 with positive refractive power;

[0006] The aperture stop is set between the first lens group G1 and the second lens group G2.

[0007] Furthermore, the lens satisfies conditions (1), (2), and (3):

[0008] 1.2≤F2 / F1≤2.0 (1)

[0009] 1.5≤F1 / FL≤2.5 (2)

[0010] 190≤2ω≤230 (3)

[0011] in,

[0012] ω: Half field of view of the optical system;

[0013] FL: Focal length of the entire optical system;

[0014] F1: Focal length of the first lens group G1;

[0015] F2: Focal length of the second lens group G2.

[0016] If the lower limit of condition 1.2≤F2 / F1≤2.0(1) is exceeded, the refractive power of the first lens group G2 is too strong, the light-gathering ability at the outermost edge becomes stronger, the exit pupil distance of the optical system is far away, and the angle of the light rays exiting from the edge tends to be gentle. Although the edge illumination will be very favorable, the size of the optical system is difficult to control, the diameter of the rear lens will be very large, and the length of the entire optical system will also be very large. If the upper limit of condition (1) is exceeded, although the length of the optical system can be effectively controlled, the final exit pupil distance is too close, the angle of the light rays exiting from the edge to the edge is too large, and the vignetting will be very serious.

[0017] If the lower limit of condition 1.5≤F1 / FL≤2.5(2) is exceeded, the refractive power of the first lens group G1 will be very strong. Although the volume of the first lens group can be effectively controlled, various aberrations are difficult to control due to the strong refractive power, and high performance is difficult. If the upper limit of condition (2) is exceeded, the refractive power of the first lens group G1 will be too weak, the light-gathering ability of the outermost edge will be weakened, the volume of the entire optical system will be difficult to control, and the diameter of the front lens will be very large.

[0018] If the lower limit of the condition 190≤2ω≤230(3) is exceeded, the field of view is not wide enough. If splicing is required, the overlapping part is insufficient, and discontinuity is likely to occur. If the upper limit of the condition (3) is exceeded, although splicing is easy, the design difficulty increases too much, and the edge performance is also difficult to guarantee.

[0019] Furthermore, the first lens group G1 is divided into two parts: the front part G1a with negative refractive power on the object side and the rear part G1b with positive refractive power on the image plane side.

[0020] Furthermore, the first lens group G1 satisfies conditions (4), (5), and (6):

[0021] 0.3≤|F1a / F1b|≤0.6 (4)

[0022] 0.85≤D i / G1R1≤1.1 (5)

[0023] 7.0≤FL / G1R1≤10 (6)

[0024] in,

[0025] Di: The effective aperture of the surface of the first lens group G1 closest to the object;

[0026] G1 R1: The radius of curvature of the surface of the first lens group G1 closest to the object;

[0027] F1 a: The focal length of G1a in the front part of the first lens group G1;

[0028] F1 b: The focal length of G1b, the rear part of the first lens group G1.

[0029] If the lower limit of conditional expression 0.3≤|F1a / F1b|≤0.6(4) is exceeded, the refractive power of the first half of the lens group G1, G1a, is too strong. Although it is easy to achieve the effective aperture Di of the lens on the object side, the strong refractive power will make it difficult to control various aberrations and achieve high performance. If the upper limit of conditional expression (4) is exceeded, although it is beneficial to correct aberrations, miniaturization design will be very difficult, resulting in a large size, which is not conducive to the space requirement of placing two lenses side by side during 3D shooting.

[0030] If the lower limit of the condition 0.85≤D i / G1R1≤1.1(5) is exceeded, the curvature radius G1R1 of the object-side lens surface will be very flat, but it will be difficult to achieve a field of view of more than 200 degrees. If the upper limit of the condition (5) is exceeded, the curvature radius G1R1 of the object-side lens surface will be too convex, or the effective aperture Di will be too large, and the curvature of G1R1 will be too strong and too convex. Although the performance is easy to achieve, it will cause the two lenses to block each other during 3D shooting, or the effective aperture Di of the object-side lens surface will be too large, exceeding the pupil distance of the human eye, and the shooting result will not achieve the effect of human eye observation.

[0031] If the lower limit of condition 7.0≤FL / G1R1≤10(6) is exceeded, the curvature radius G1R1 of the object-side lens surface becomes very gentle, but it is difficult to achieve a field of view of more than 200 degrees. If the upper limit of condition (6) is exceeded, the curvature radius G1R1 of the object-side lens surface becomes too convex, and the curvature of G1R1 becomes too strong and too convex. Although the performance is easy to achieve, it will cause the two lenses to block each other's field of view, making the field of view not wide enough.

[0032] Furthermore, the front portion G1 a consists of three consecutive negative lenses.

[0033] Furthermore, the latter part G1b is a biconvex, bi-faceted aspherical surface.

[0034] This invention also provides a camera having the aforementioned 3D fisheye lens.

[0035] This utility model also provides a camera having the aforementioned 3D fisheye lens.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] This invention provides a miniaturized, high-performance fisheye lens with a large image field, a field of view exceeding 200 degrees, a sufficiently gentle radius of curvature of the first glass element, minimal mutual occlusion, and a sufficiently small effective aperture, capable of mimicking the binocular visual effect of the human eye. Attached Figure Description

[0038] Figure 1 This is an optical structure diagram of Embodiment 1 of this utility model;

[0039] Figure 2 These are the spherical aberration at infinity, field curvature aberration, distortion aberration, and magnification chromatic aberration of Example 1;

[0040] Figure 3 This is an optical structure diagram of Embodiment 2 of this utility model;

[0041] Figure 4These are the spherical aberration at infinity, field curvature aberration, distortion aberration, and magnification chromatic aberration of Example 2;

[0042] Figure 5 This is an optical structure diagram of Embodiment 3 of this utility model;

[0043] Figure 6 These are the spherical aberration at infinity, field curvature aberration, distortion aberration, and magnification chromatic aberration of Example 3. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments. The present invention includes, but is not limited to, the following embodiments.

[0045] Example 1: As Figure 1 As shown, from the object side to the image plane side, it includes a first lens group G1 with positive refractive power, an aperture stop, and a second lens group G2 with positive refractive power. The first lens group G1 is divided into two parts: a front part G1a with negative refractive power on the object side and a rear part G1b with positive refractive power on the image plane side. The front part G1a consists of three consecutive negative lenses, and the rear part G1b is a biconvex double-sided aspherical surface.

[0046] Example 1 shows spherical aberration at infinity, field curvature aberration, distortion aberration, and magnification chromatic aberration, such as... Figure 2 As shown.

[0047] The data for Example 1 are as follows.

[0048] R(mm): Radius of curvature of each surface;

[0049] D (mm): Spacing between lenses and lens thickness;

[0050] Nd: The refractive index of each glass along the d-line;

[0051] Vd: Abbe number of glass;

[0052] Focal length: 7.563;

[0053] FNO: 3.6;

[0054] Half-stroke angle ω: 106°.

[0055] NS R D Nd ABV 1 62.0000 4.5716 1.92286 20.88 2 17.5954 8.5156 3 52.8532 2.0000 1.72916 54.67 4 17.6444 8.1577 5 -31.7071 1.5000 1.45860 90.19 6 19.2200 6.9370 7ASPH 20.7983 6.8701 1.88982 34.90 8ASPH -35.4245 9.8970 9STOP inf 1.0000 10 -35.7231 1.0000 1.80906 23.44 11 16.5801 2.3130 1.49700 81.61 12 -20.2560 1.5320 13 236.7912 2.0904 1.74523 52.47 14 -42.5360 0.1500 15 18.4235 6.4902 1.49700 81.61 16 -15.0920 1.0000 1.75702 24.91 17 -45.1668 1.0000 18 inf 2.0000 1.51680 64.20 19 inf 11.0012

[0056]

[0057]

[0058] Example 2: As Figure 3As shown, from the object side to the image plane side, it includes a first lens group G1 with positive refractive power, an aperture stop, and a second lens group G2 with positive refractive power. The first lens group G1 is divided into two parts: a front part G1a with negative refractive power on the object side and a rear part G1b with positive refractive power on the image plane side. The front part G1a consists of three consecutive negative lenses, and the rear part G1b is a biconvex double-sided aspherical surface.

[0059] Example 2: spherical aberration at infinity, field curvature aberration, distortion aberration, and magnification chromatic aberration, such as... Figure 4 As shown.

[0060] The data for Example 2 are as follows:

[0061] R(mm): Radius of curvature of each surface;

[0062] D (mm): Spacing between lenses and lens thickness;

[0063] Nd: The refractive index of each glass along the d-line;

[0064] Vd: Abbe number of glass;

[0065] Focal length: 7.3643;

[0066] FNO: 3.0;

[0067] Half-stroke angle ω: 105°.

[0068]

[0069]

[0070]

[0071] Example 3: As Figure 5 As shown, from the object side to the image plane side, it includes a first lens group G1 with positive refractive power, an aperture stop, and a second lens group G2 with positive refractive power. The first lens group G1 is divided into two parts: a front part G1a with negative refractive power on the object side and a rear part G1b with positive refractive power on the image plane side. The front part G1a consists of three consecutive negative lenses, and the rear part G1b is a biconvex double-sided aspherical surface.

[0072] Example 3: spherical aberration at infinity, field curvature aberration, distortion aberration, and magnification chromatic aberration, such as... Figure 6 As shown.

[0073] The data for Example 3 are as follows:

[0074] R(mm): Radius of curvature of each surface;

[0075] D (mm): Spacing between lenses and lens thickness;

[0076] Nd: The refractive index of each glass along the d-line;

[0077] Vd: Abbe number of glass;

[0078] Focal length: 7.6380;

[0079] FNO: 4.0;

[0080] Half-stroke angle ω: 104°.

[0081] NS R D Nd ABV 1 65.0000 3.0000 1.92286 20.88 2 19.8467 8.6105 3 55.7588 2.6097 1.72916 57.00 4 18.5035 8.7790 5 -36.9990 1.0000 1.45860 90.19 6 22.1486 8.9711 7ASPH 22.0853 6.9006 1.91082 35.25 8ASPH -44.3444 10.4419 9STOP inf 1.0000 10 -22.7771 1.0000 1.76639 24.59 11 18.2380 2.3552 1.49700 81.61 12 -18.4065 1.5055 13 -1482.1249 2.0000 1.81783 47.74 14 -33.9984 0.1500 15 18.2809 6.5731 1.49700 81.61 16 -15.2511 1.1034 1.75378 24.34 17 -49.6402 1.0000 18 inf 2.0000 1.51680 64.20 19 inf 11.0054

[0082]

[0083]

[0084] In the above embodiments, the aspherical shape is defined as follows:

[0085] y: Radial coordinate starting from the optical axis.

[0086] z: The offset along the optical axis from the point where the aspherical surface intersects the optical axis. r: The radius of curvature of the reference sphere of the aspherical surface.

[0087] K, aspheric coefficients of the 4th, 6th, 8th, 10th, and 12th orders.

[0088]

[0089] Conditional summary table:

[0090]

[0091]

[0092]

[0093] The 3D fisheye lens provided in any of the above embodiments can be used in cameras and camcorders.

[0094] The above description is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of this utility model.

Claims

1. A 3D fisheye lens, characterized in that, from the object side to the image plane side, it sequentially includes a first lens group G1 with positive refractive power and a second lens group G2 with positive refractive power; The aperture stop is set between the first lens group G1 and the second lens group G2; The lens satisfies conditions (1), (2), and (3): 1.2≤F2 / F1≤2.0 (1) 1.5≤F1 / FL≤2.5 (2) 190≤2ω≤230 (3) in, ω: Half field of view of the optical system; FL: Focal length of the entire optical system; F1: Focal length of the first lens group G1; F2: Focal length of the second lens group G2; The first lens group G1 is divided into two parts: the front part G1a with negative refractive power on the object side and the rear part G1b with positive refractive power on the image plane side. The first lens group G1 satisfies conditions (4), (5), and (6): 0.3≤|F1 a / F1 b|≤0.6 (4) 0.85≤Di / G1 R1≤1.1 (5) 7.0≤FL / G1 R1≤10 (6) in, Di: Effective aperture of the surface of the first lens group G1 closest to the object; G1 R1: The radius of curvature of the surface of the first lens group G1 closest to the object; F1 a: The focal length of G1 a in the front part of the first lens group G1; F1 b: The focal length of G1 b, the rear portion of the first lens group G1.

2. The 3D fisheye lens according to claim 1, characterized in that, The front part G1 a consists of three consecutive negative lenses.

3. The 3D fisheye lens according to claim 1, characterized in that, The latter part G1b is a biconvex, bi-faceted aspherical surface.

4. A camera having a 3D fisheye lens as described in any one of claims 1-3.

5. A camera having a 3D fisheye lens as described in any one of claims 1-3.

Images