Large-aperture camera lens with focal length of 23 mm

Abstract

The utility model discloses a 23mm-focal-length large-aperture camera lens. The 23mm-focal-length large-aperture camera lens sequentially comprises a first lens group, an iris diaphragm, a second lens group and a third lens group from an object side to an imaging surface, the first lens group serves as a fixed group, has positive focal power, and comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens; the second lens group is used as a focusing group, has positive focal power, and comprises a seventh lens, an eighth lens and a ninth lens; the third lens group serves as a fixed group, has negative focal power and comprises a tenth lens, an eleventh lens and a twelfth lens; according to the utility model, the aspheric lens is used to optimize aberration, the cost and appearance advantages are obtained, the high performance of the F1.4 maximum aperture is realized, the imaging is excellent at infinity and close-up distance, the distortion is less than 2%, the discomfort of video shooting is greatly reduced, and the shooting experience is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to camera lens technical field, concretely is a 23mm focal length large aperture camera lens. BACKGROUND

[0002] Because of the popularity of short videos on social platforms, more and more netizens share and exchange by shooting daily vlogs. For these groups, having a small and portable automatic mirrorless camera lens is twice the result with half the effort. The early market mirrorless lens mainly focuses on shooting quality, matching customer needs through large aperture, small distortion, and blur effect, but the early products do not take into account the uncomfortable breathing and shaking of the viewer during video shooting. If a lens can be developed that not only has excellent resolution, small distortion, large aperture, and portability, but also greatly reduces breathing and shaking during video shooting, it will be highly valued by professionals in the market and have great product competitiveness. Therefore, the utility model designs a 23mm focal length large aperture camera lens to improve the above problems. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the utility model is to provide a 23mm focal length large aperture camera lens, which uses aspherical lenses to optimize aberration, achieves high performance of F1.4 maximum aperture while achieving cost and appearance advantages, and achieves excellent imaging at infinite and close-up distances with less than 2% distortion, greatly reducing the discomfort of video shooting and improving the photography experience.

[0004] To achieve the above purpose, the utility model provides the following technical scheme:

[0005] A 23mm focal length large aperture camera lens sequentially includes a first lens group, a variable diaphragm, a second lens group, and a third lens group from the object side to the imaging surface;

[0006] The first lens group is a fixed group with positive optical power, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens;

[0007] The second lens group is a focusing group with positive optical power, including a seventh lens, an eighth lens, and a ninth lens;

[0008] The third lens group is a fixed group with negative optical power, including a tenth lens, an eleventh lens, and a twelfth lens;

[0009] The first lens and the third lens are crescent negative lenses curved towards the image side, satisfying the following conditions:

[0010] 0.96 < F1 / F3 < 1.89

[0011] 0.92 < G1R2 / G3R2 < 1.87

[0012] wherein, F1 is the focal length of the first lens, F3 is the focal length of the third lens, G1R2 is the radius of curvature of the side of the first lens close to the imaging plane, and G3R2 is the radius of curvature of the side of the third lens close to the imaging plane.

[0013] Preferably, the second lens is a meniscus positive lens curved towards the imaging plane, and satisfies the following condition:

[0014] Nd2 > 1.84

[0015] wherein, Nd2 is the refractive index of the second lens.

[0016] Preferably, the focal length of the first lens group satisfies the following condition:

[0017] 0.92 < FG1 / f < 1.85

[0018] wherein, FG1 is the focal length of the first lens group, and f is the focal length of the camera lens optical system. Preferably, the second lens in the second lens group satisfies the following condition:

[0019] Vd8 > 70.4

[0020] wherein, Vd8 is the Abbe number of the second lens in the second lens group.

[0021] Preferably, the third lens in the second lens group satisfies the following condition:

[0022] Nd9 > 1.84

[0023] wherein, Nd9 is the refractive index of the third lens in the second lens group.

[0024] Preferably, the focal length of the second lens group satisfies the following condition:

[0025] 1.48 < FG2 / f < 3.70

[0026] wherein, FG2 is the focal length of the second lens group, and f is the focal length of the camera lens optical system.

[0027] Preferably, the third lens group contains an air gap with a double convex shape, and satisfies the following condition:

[0028] -0.5 < (A10R2+A10R1) / (A10R2-A10R1) < 1.5

[0029] Wherein, A10R1 is the curvature radius of the double-convex shape air gap in the third lens group near the object side, A10R2 is the curvature radius of the double-convex shape air gap in the third lens group near the imaging surface.

[0030] Compared with the prior art, the utility model has the beneficial effects that:

[0031] The utility model discloses use aspheric lens optimization aberration, and the structure is small and light, and the high performance of F1.4 maximum aperture is realized while the cost and appearance advantage are obtained, and the imaging is excellent at infinite and near distance, and the distortion is less than 2%; The system is divided into 3 groups of mirror groups, and the structure is simplified, and the tolerance tolerance is reduced;Through the calculation, the moving group that satisfies the low breathing effect is selected, the light incidence position and length and the positive and negative focal length ratio of the moving group are adjusted, the angle of view change of the system when shooting at near and far tends to be gentle, the discomfort of video shooting is greatly reduced, and the photography experience is improved;The size and weight of the moving lens are small, the motor load is small, and the focusing efficiency is effectively guaranteed. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is the lens structure schematic diagram of 23mm focal length large aperture camera lens;

[0033] Figure 2 It is the spherical aberration curve, field curve diagram and distortion curve diagram of 23mm focal length large aperture camera lens;

[0034] Figure 3 It is the lens structure schematic diagram of another embodiment of 23mm focal length large aperture camera lens;

[0035] Figure 4 It is the spherical aberration curve, field curve diagram and distortion curve diagram of another embodiment of 23mm focal length large aperture camera lens.

[0036] In the drawing: G1, first lens group;G2, second lens group;G3, third lens group;1, first lens;2, second lens;3, third lens;4, fourth lens;5, fifth lens;6, sixth lens;7, seventh lens;8, eighth lens;9, ninth lens;10, tenth lens;11, eleventh lens;12, twelfth lens;13, thirteenth lens. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments, and all other embodiments obtained by those skilled in the art without creative labor based on the embodiments in the utility model belong to the protection scope of the utility model.

[0038] Embodiment 1:

[0039] Referring to Figure 1 The embodiment provides a 23mm focal length large aperture camera lens, which comprises, in sequence from an object side to an image plane, a first lens group G1, a variable diaphragm, a second lens group G2 and a third lens group G3.

[0040] The first lens group G1 is a fixed group, has positive refractive power, and comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5 and a sixth lens 6.

[0041] The second lens group G2 is a focusing group (moving group), has positive refractive power, and comprises a seventh lens 7, an eighth lens 8 and a ninth lens 9.

[0042] The third lens group G3 is a fixed group, has negative refractive power, and comprises a tenth lens 10, an eleventh lens 11 and a twelfth lens 12, wherein the number of lenses in the first lens group G1, the second lens group G2 and the third lens group G3 is designed according to design and use requirements, and the number of lenses is increased or decreased, which belongs to the protection range of the embodiment.

[0043] The first lens 1 and the third lens 3 are meniscus negative lenses that are curved toward an image plane, and satisfy the following conditions:

[0044] 0.96<F1 / F3<1.89

[0045] 0.92<G1 R2 / G3R2<1.87

[0046] Wherein, F1 is the focal length of the first lens 1, F3 is the focal length of the third lens 3, G1 R2 is the curvature radius of the side of the first lens 1 close to the image plane, and G3R2 is the curvature radius of the side of the third lens 3 close to the image plane.

[0047] In the embodiment, the second lens 2 is a meniscus positive lens that is curved toward the image plane, and satisfies the following conditions:

[0048] Nd2>1.84

[0049] Wherein, ND2 is the refractive index of the second lens 2.

[0050] In the embodiment, the focal length of the first lens group G1 satisfies the following conditions:

[0051] 0.92<FG1 / f<1.85

[0052] Wherein, FG1 is the focal length of the first lens group G1, and f is the focal length of the camera lens optical system.

[0053] In the present embodiment, the second lens (i.e. the eighth lens 8) in the second lens group G2 satisfies the following condition:

[0054] Vd8> 70.4

[0055] wherein Vd8 is the Abbe number of the second lens (the eighth lens 8) in the second lens group G2.

[0056] In the present embodiment, the third lens (i.e. the ninth lens 9) in the second lens group G2 satisfies the following condition:

[0057] Nd9> 1.84

[0058] wherein Nd9 is the refractive index of the third lens (the ninth lens 9) in the second lens group G2. In the present embodiment, the focal length of the second lens group G2 satisfies the following condition:

[0059] 1.48 < FG2 / f < 3.70

[0060] wherein FG2 is the focal length of the second lens group G2, and f is the focal length of the camera lens optical system.

[0061] In the present embodiment, the third lens group G3 contains an air gap with a biconvex shape, which satisfies the following condition:

[0062] -0.5 < (A10R2 + A10R1) / (A10R2 - A10R1) < 1.5

[0063] wherein A10R1 is the radius of curvature of the side of the biconvex shape air gap in the third lens group G3 closer to the object side, and A10R2 is the radius of curvature of the side of the biconvex shape air gap in the third lens group G3 closer to the imaging surface.

[0064] As a preferred embodiment of the present technical solution, the parameters of the camera lens embodiment are shown in Table 1 below, wherein the aspherical coefficients of the aspherical lenses are shown in Table 2 below, and the surface number in the surface number column shows the surface number when the surface closer to the object side is set as the first surface and the surface number is sequentially increased towards the imaging surface side. The shape parameters of each lens are as follows:

[0065] Table 1

[0066]

[0067] Table 2

[0068] Surface No. 10 11 22 23 k -5.33 0.01 63.987 99 A4 -5.926e-06 4.936e-07 -1.773e-04 -1.302e-04 A6 3.316e-09 5.558e-09 -2.253e-07 -1.735e-07 A8 4.182e-11 6.001e-11 1.249e-08 8.453e-09 A10 -1.124e-12 -8.217e-13 -1.518-10 -7.081e-11 A12 2.967e-15 1.801e-15 7.222e-13 2.920e-13

[0069] As a preferred embodiment of the technical solution, the positions of the focus compensation groups (moving groups) of the camera lens in the present embodiment under different focus states are shown in Table 3 below, that is, the numerical values of the two states of D1 and D2 in Table 1:

[0070] Table 3

[0071] Conjugate distance Infinity Closest (0.25 m) D1 10.48 mm 5.28 mm D2 0.8 mm 6 mm

[0072] As a preferred technical solution, the physical parameters of the camera lens in the embodiment are shown in Table 4 as follows:

[0073] Table 4

[0074] Focal length f 23.01 mm Relative aperture FNO. 1.45 Field of view angle ω 66.2° Optical total length 98 mm

[0075] Figure 2 For the spherical aberration curve of the camera lens, the field curvature curve of the camera lens and the distortion curve of the camera lens in the embodiment, it can be seen that the camera lens of the embodiment has good imaging effect.

[0076] In the embodiment, by limiting the above condition formula, the aspheric lens is used to optimize aberration, the structure is short and light, the cost and appearance advantages are obtained, the high performance of F1.4 maximum aperture is realized, the imaging at infinite distance and close-up distance is excellent, and the distortion is less than 2%; the system is divided into three groups of lenses, the structure is simplified, and the tolerance accommodation degree is reduced; by calculation, the moving group satisfying the low breathing effect is selected, the light incidence position and length of the moving group and the positive and negative focal length ratio are adjusted, so that the angle of view changes tend to be flat when the system switches between far and close shooting, the discomfort of video shooting is greatly reduced, and the photography experience is improved; the size and weight of the moving lens are small, the motor load is small, and the focusing efficiency is effectively guaranteed.

[0077] Embodiment 2:

[0078] Please refer to Figure 3 The embodiment provides a 23mm focal length large aperture camera lens, which comprises a first lens group G1, a variable diaphragm, a second lens group G2 and a third lens group G3 from an object side to an imaging surface in sequence.

[0079] The first lens group G1 is a fixed group, has positive optical power, and comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a seventh lens 7.

[0080] The second lens group G2 is a focusing group (moving group), has positive optical power, and comprises an eighth lens 8, a ninth lens 9 and a tenth lens 10.

[0081] The third lens group G3 is a fixed group, has negative optical power, and comprises an eleventh lens 11, a twelfth lens 12 and a thirteenth lens 13, wherein the number of lenses in the first lens group G1, the second lens group G2 and the third lens group G3 is designed according to design and use requirements, and the increase or decrease of the number of lenses belongs to the protection scope of the embodiment.

[0082] The first lens 1 and the third lens 3 are meniscus negative lenses curved toward the image side, and satisfy the following conditions:

[0083] 0.96 < F1 / F3 < 1.89

[0084] 0.92 < G1R2 / G3R2 < 1.87

[0085] wherein F1 is the focal length of the first lens 1, F3 is the focal length of the third lens 3, G1R2 is the radius of curvature of the side of the first lens 1 close to the image side, and G3R2 is the radius of curvature of the side of the third lens 3 close to the image side.

[0086] In the present embodiment, the second lens 2 is a meniscus positive lens curved toward the image side, and satisfies the following conditions:

[0087] Nd2 > 1.84

[0088] wherein Nd2 is the refractive index of the second lens 2.

[0089] In the present embodiment, the focal length of the first lens group G1 satisfies the following condition:

[0090] 0.92 < FG1 / f < 1.85

[0091] wherein FG1 is the focal length of the first lens group G1, and f is the focal length of the camera lens optical system.

[0092] In the present embodiment, the second lens (i.e., the ninth lens 9) in the second lens group G2 satisfies the following condition:

[0093] Vd8 > 70.4

[0094] wherein Vd8 is the Abbe number of the second lens (the ninth lens 9) in the second lens group G2.

[0095] In the present embodiment, the third lens (i.e., the tenth lens 10) in the second lens group G2 satisfies the following condition:

[0096] Nd9 > 1.84

[0097] wherein Nd9 is the refractive index of the third lens (the tenth lens 10) in the second lens group G2. In the present embodiment, the focal length of the second lens group G2 satisfies the following condition:

[0098] 1.48 < FG2 / f < 3.70

[0099] wherein FG2 is the focal length of the second lens group G2, and f is the focal length of the camera lens optical system.

[0100] In the embodiment, the third lens group G3 contains a biconvex air gap, which satisfies the following conditions:

[0101] -0.5<(A10R2+A10R1) / (A10R2-A10R1)<1.5

[0102] Wherein, A10R1 is the curvature radius of the side of the biconvex air gap in the third lens group G3 close to the object side, and A10R2 is the curvature radius of the side of the biconvex air gap in the third lens group G3 close to the imaging surface.

[0103] As a preferred embodiment of the technical scheme, the parameters of the camera lens embodiment are shown in Table 5, wherein the aspherical coefficients of the aspherical lens are shown in Table 6, the face number is shown in the surface serial number column when the face close to the object side is set as the first face and the face number is sequentially increased towards the imaging surface side, and the shape parameters of each lens are as follows:

[0104] Table 5

[0105]

[0106]

[0107] Table 6

[0108] Surface No. 24 25 k -3.6048 -1.1307 A4 -9.293e-06 -6.787e-05 A6 2.823e-07 2.277e-07 A8 1.844e-09 2.138e-09 A10 -3.486e-11 -2.906e-11 A12 1.684e-13 1.256e-13

[0109] As a preferred embodiment of the technical scheme, the positions of the focusing compensation groups (moving groups) of the camera lens in different focusing states in the embodiment are shown in Table 3, that is, the values of the two states of D1 and D2 in Table 1:

[0110] Table 7

[0111] Conjugate distance Infinity Closest (0.25 m) D1 8.98 mm 5.08 mm D2 1.3 mm 5.2 mm

[0112] As a preferred embodiment of the technical scheme, the physical parameters of the camera lens in the embodiment are shown in Table 4:

[0113] Table 8

[0114] Focal length f 22.99 mm Relative aperture FNO. 1.46 Field of view angle ω 67.5° Optical total length 97 mm

[0115] Figure 4 For the spherical aberration curve of the camera lens, the field curvature curve of the camera lens and the distortion curve of the camera lens in the embodiment, it can be seen that the camera lens in the embodiment has good imaging effect.

[0116] The above embodiment is a preferred implementation scheme of the utility model, in addition to this, the utility model can be realized in other ways, and any obvious replacement without departing from the technical scheme concept is within the protection scope of the utility model.

Claims

1. A 23mm focal length, wide aperture camera lens characterized by: From the object side to the imaging plane successively include first lens group (G1), variable diaphragm, second lens group (G2) and third lens group (G3); The first lens group (G1) is a fixed group, the optical power is positive, including first lens (1), second lens (2), third lens (3), fourth lens (4), fifth lens (5) and sixth lens (6); The second lens group (G2) is a focusing group, the optical power is positive, including seventh lens (7), eighth lens (8) and ninth lens (9); The third lens group (G3) is a fixed group, the optical power is negative, including tenth lens (10), eleventh lens (11) and twelfth lens (12); The first lens (1) and third lens (3) are meniscus negative lenses bending towards the image side, satisfying the following conditions: 0.96<F1 / F3<1.89 0.92<G1R2 / G3R2<1.87 Wherein, F1 is the focal length of the first lens (1), F3 is the focal length of the third lens (3), G1 R2 is the radius of curvature of the side of the first lens (1) close to the imaging surface, G3R2 is the radius of curvature of the side of the third lens (3) close to the imaging surface.

2. The 23mm focal length, wide aperture camera lens of claim 1, wherein: The second lens (2) is a meniscus positive lens bending towards the imaging surface, satisfying the following conditions: Nd2>1.84 Wherein, ND2 is the refractive index of the second lens (2).

3. The 23mm focal length, wide aperture camera lens of claim 1, wherein: The focal length of the first lens group (G1) satisfies the following conditions: 0.92<FG1 / f<1.85 Wherein, FG1 is the focal length of the first lens group (G1), f is the focal length of the camera lens optical system.

4. The 23mm focal length, wide aperture camera lens of claim 1, wherein: The second lens in the second lens group (G2) satisfies the following conditions: Vd8>70.4 Wherein, Vd8 is the Abbe number of the second lens in the second lens group (G2).

5. The 23mm focal length, wide aperture camera lens of claim 1, wherein: The third lens in the second lens group (G2) satisfies the following conditions: Nd9>1.84 Wherein, Nd9 is the refractive index of the third lens in the second lens group (G2).

6. The 23mm focal length, wide-aperture camera lens of claim 1, wherein: The focal length of the second lens group (G2) satisfies the following conditions: 1.48<FG2 / f<3.70 Wherein, FG2 is the focal length of the second lens group (G2), f is the focal length of the camera lens optical system.

7. The 23mm focal length, wide-aperture camera lens of claim 1, wherein: The third lens group (G3) contains an air gap with a double convex shape, satisfying the following conditions: -0.5<(A10R2+A10R1) / (A10R2-A10R1)<1.5 Wherein, A10R1 is the radius of curvature of the side of the double convex shape air gap in the third lens group (G3) close to the object side, A10R2 is the radius of curvature of the side of the double convex shape air gap in the third lens group (G3) close to the imaging surface.

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