Camera lens

Abstract

The present application relates to the field of optical lens, provide a kind of camera lens, camera lens is sequentially configured with the first lens with positive refractive power from object side to image side, the second lens with positive refractive power, the third lens with negative refractive power, the fourth lens with negative refractive power, the fifth lens with positive refractive power, and the sixth lens with negative refractive power, and satisfy the following relationship: (TTL / LB) when shooting≤2.20;7.50≤D12 / d2≤8.50;0.04≤d6 / f≤0.08;-1.00≤R6 / R7≤-0.35.The present application is low height when retraction, is narrow angle and has good optical characteristics when shooting.

Description

Technical Field

[0001] This invention relates to a camera lens. In particular, it relates to a camera lens that is suitable for camera components of smartphones, digital cameras, etc., that use high-resolution imaging elements such as CCDs and CMOS sensors, and that has a narrow field of view (hereinafter referred to as 2ω) of 50° or less during photography, good optical characteristics, a TTL / IH of 1.40 or less when retracted, a low height when retracted, and is composed of six lenses. Background Technology

[0002] Since the TTL (Total Optical Length) of a camera lens increases as the field of view narrows, there has been a recent search for a camera lens that provides a narrow angle of view and good optical characteristics during photography, while shortening the TTL by retracting the lens barrel into the camera during non-photography operations, and also lowering the lens height during retraction.

[0003] The development of a camera lens consisting of six lenses with a narrow angle of view and good optical properties is underway. Patent Document 1 proposes a camera lens with the following structure: from the object side to the image side, it consists of a first lens with positive refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens with negative refractive power, a fifth lens with positive refractive power, and a sixth lens with negative refractive power.

[0004] Although the 2ω of the camera lens disclosed in Embodiment 3 of Patent Document 1 is narrowed to 49.4°, the ratio of TTL to LB during photography is insufficient, and therefore the height reduction during retraction is also insufficient.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Chinese Patent Publication No. CN108535844A Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The object of the present invention is to provide a camera lens that is low in height when retracted, has a narrow angle and good optical characteristics when taking pictures, and is composed of six lenses.

[0010] Methods for solving problems

[0011] To achieve the above objectives, the inventors of this invention carefully studied the ratio of TTL (total optical length) to LB (back focal length) during photography, the ratio of the axial distance from the object side of the first lens to the image side of the second lens to the axial distance from the image side of the first lens to the object side of the second lens, the ratio of the axial distance from the image side of the third lens to the object side of the fourth lens to the overall focal length of the camera lens, and the ratio of the radius of curvature of the image side of the third lens to the radius of curvature of the object side of the fourth lens. As a result, they found that a camera lens that improves the problems of the prior art could be obtained, and thus the present invention was conceived.

[0012] An embodiment of the present invention provides a camera lens, wherein the camera lens is provided with a first lens having positive refractive power, a second lens having positive refractive power, a third lens having negative refractive power, a fourth lens having negative refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power in sequence from the object side to the image side, and satisfies the following relationships (1) to (4):

[0013] (TTL / LB) during photography ≤ 2.20 (1)

[0014] 7.50≤D12 / d2≤8.50 (2)

[0015] 0.04≤d6 / f≤0.08 (3)

[0016] -1.00≤R6 / R7≤-0.35 (4)

[0017] in,

[0018] TTL: Total optical length (axial distance from the object-side surface of the first lens to the image plane);

[0019] LB: Back focal length (the axial distance from the image-side surface of the sixth lens to the image plane);

[0020] D12: The axial distance from the object-side surface of the first lens to the image-side surface of the second lens;

[0021] d2: The axial distance from the image-side surface of the first lens to the object-side surface of the second lens;

[0022] f: The overall focal length of the camera lens;

[0023] d6: The axial distance from the image-side surface of the third lens to the object-side surface of the fourth lens;

[0024] R6: Radius of curvature of the image-side surface of the third lens;

[0025] R7: The radius of curvature of the object-side surface of the fourth lens.

[0026] Preferably, the following relation (5) is satisfied:

[0027] 0.60≤f1 / f≤0.80 (5)

[0028] in,

[0029] f: The overall focal length of the camera lens;

[0030] f1: Focal length of the first lens.

[0031] Preferably, the following relation (6) is satisfied:

[0032] 0.90≤f² / f≤1.30 (6)

[0033] in,

[0034] f: The overall focal length of the camera lens;

[0035] f2: Focal length of the second lens.

[0036] Preferably, the following relation (7) is satisfied:

[0037] -0.70≤f3 / f≤-0.50 (7)

[0038] in,

[0039] f: The overall focal length of the camera lens;

[0040] f3: Focal length of the third lens.

[0041] Preferably, the following relation (8) is satisfied:

[0042] 0.05≤d8 / f≤0.10 (8)

[0043] in,

[0044] f: The overall focal length of the camera lens;

[0045] d8: The axial distance from the image side of the fourth lens to the object side of the fifth lens.

[0046] Invention Effects

[0047] According to the present invention, in particular, there is an invention relating to a camera lens that is suitable for camera components of smartphones, digital cameras, etc., which use high-pixel CCD, CMOS, or other imaging elements, and has a narrow angle of 2ω≤50° and good optical characteristics during photography, and has a low height when retracted when the TTL / IH is ≤1.40, and is composed of six lenses. Attached Figure Description

[0048] Figure 1 This is a diagram showing a schematic structure of the camera lens LA according to Embodiment 1 of the present invention.

[0049] Figure 2 This is a diagram showing the axial spherical aberration, astigmatism, and distortion of the camera lens LA according to Embodiment 1 of the present invention.

[0050] Figure 3 This is a diagram showing a schematic structure of the camera lens LA according to Embodiment 2 of the present invention.

[0051] Figure 4 This is a diagram showing the axial spherical aberration, astigmatism, and distortion of the camera lens LA according to Embodiment 2 of the present invention.

[0052] Figure 5 This is a diagram showing a schematic structure of the camera lens LA according to Embodiment 3 of the present invention.

[0053] Figure 6 This is a diagram showing the axial spherical aberration, astigmatism, and distortion of the camera lens LA according to Embodiment 3 of the present invention. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings and embodiments. To make the objectives, technical solutions, and advantages of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0055] An embodiment of the camera lens of the present invention will be described. The camera lens LA has a six-element lens system, in which a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 are arranged sequentially from the object side to the image side. A glass plate GF is disposed between the sixth lens L6 and the image plane. This glass plate GF can be assumed to include a glass cover and various filters. In the present invention, the glass plate GF can be positioned in different locations or omitted altogether.

[0056] The first lens L1 has positive refractive power, the second lens L2 has positive refractive power, the third lens L3 has negative refractive power, the fourth lens L4 has negative refractive power, the fifth lens L5 has positive refractive power, and the sixth lens L6 has negative refractive power. To effectively correct for various aberrations, it is desirable to make all surfaces of these six lenses aspherical.

[0057] The camera lens LA satisfies the following relationship (1):

[0058] (TTL / LB) during photography ≤ 2.20 (1)

[0059] Equation (1) specifies the ratio of the total optical length (the on-axis distance from the object side surface S1 of the first lens L1 to the image plane) TTL during photography to the back focal length (the on-axis distance from the image side surface S12 of the sixth lens L6 to the image plane) LB during photography. Within the range of Equation (1), it is easy to achieve a lower height during contraction, and therefore it is preferred.

[0060] The camera lens LA satisfies the following relationship (2):

[0061] 7.50≤D12 / d2≤8.50 (2)

[0062] Equation (2) specifies the ratio of the axial distance D12 between the object-side surface S1 of the first lens L1 and the image-side surface S4 of the second lens L2 to the axial distance d2 between the image-side surface S2 of the first lens L1 and the object-side surface S3 of the second lens L2. Within the range of equation (2), it is easy to achieve correction of various aberrations under conditions of reduced height during contraction and narrowed field of view during photography, and is therefore preferred.

[0063] The camera lens LA satisfies the following relationship (3):

[0064] 0.04≤d6 / f≤0.08 (3)

[0065] Equation (3) specifies the ratio of the on-axis distance d6 from the image-side surface S6 of the third lens L3 to the object-side surface S7 of the fourth lens L4 to the focal length f of the entire camera lens LA. Within the range of equation (3), it is easy to achieve correction of various aberrations under conditions of reduced height during contraction and narrowed field of view during photography, and is therefore preferred.

[0066] The camera lens LA satisfies the following relationship (4):

[0067] -1.00≤R6 / R7≤-0.35 (4)

[0068] Equation (4) specifies the ratio of the radius of curvature R6 of the image side surface S6 of the third lens L3 to the radius of curvature R7 of the object side surface S7 of the fourth lens L4. Within the range of equation (4), it is easy to achieve correction of various aberrations under conditions of reduced height during contraction and narrowed field of view during photography, and is therefore preferred.

[0069] The camera lens LA satisfies the following relationship (5):

[0070] 0.60≤f1 / f≤0.80 (5)

[0071] Equation (5) specifies the ratio of the focal length f1 of the first lens L1 to the focal length f of the entire camera lens LA. Within the range of equation (5), it is easy to achieve correction of various aberrations under conditions of reduced height during contraction and narrowed field of view during photography, and is therefore preferred.

[0072] The camera lens LA satisfies the following relationship (6):

[0073] 0.90≤f² / f≤1.30 (6)

[0074] Equation (6) specifies the ratio of the focal length f2 of the second lens L2 to the focal length f of the entire camera lens LA. Within the range of equation (6), it is easy to achieve correction of various aberrations under conditions of reduced height during contraction and narrowed field of view during photography, and is therefore preferred.

[0075] The camera lens LA satisfies the following relationship (7):

[0076] -0.70≤f3 / f≤-0.50 (7)

[0077] Equation (7) specifies the ratio of the focal length f3 of the third lens L3 to the focal length f of the entire camera lens LA. Within the range of equation (7), it is easy to achieve correction of various aberrations under conditions of reduced height during contraction and narrowed field of view during photography, and is therefore preferred.

[0078] The camera lens LA satisfies the following relationship (8):

[0079] 0.05≤d8 / f≤0.10 (8)

[0080] Equation (8) defines the ratio of the on-axis distance d8 from the image-side surface S8 of the fourth lens L4 to the object-side surface S9 of the fifth lens L5 to the overall focal length f of the camera lens LA. Within the range of equation (8), it is easy to achieve correction of various aberrations under conditions of reduced height during contraction and narrowed field of view during photography, and is therefore preferred.

[0081] By having the six lenses constituting the camera lens LA satisfy the above-mentioned structure and relationship, a camera lens can be obtained that has a narrow angle of 2ω≤50° and good optical characteristics during photography, has a low height when the TTL / IH is ≤1.40 when the lens is retracted, and is composed of six lenses.

[0082] The following examples illustrate the camera lens LA of the present invention. The symbols used in each embodiment are shown below. It should be noted that the units for distance, radius, and on-axis thickness are all millimeters (mm).

[0083] f: The overall focal length of the camera lens (LA);

[0084] f1: Focal length of the first lens L1;

[0085] f2: Focal length of the second lens L2;

[0086] f3: Focal length of the third lens L3;

[0087] f4: Focal length of the fourth lens L4;

[0088] f5: Focal length of the fifth lens L5;

[0089] f6: Focal length of the sixth lens L6;

[0090] FNO: Aperture value (the ratio of the effective focal length of a camera lens to the entrance pupil diameter), F-number;

[0091] 2ω: Full-view perspective;

[0092] STOP: Aperture;

[0093] R: Radius of curvature of the optical surface; for lenses, it is the central radius of curvature.

[0094] R1: Radius of curvature of the object surface S1 of the first lens L1;

[0095] R2: Radius of curvature of the image-side surface S2 of the first lens L1;

[0096] R3: The radius of curvature of the object surface S3 of the second lens L2;

[0097] R4: Radius of curvature of the image-side surface S4 of the second lens L2;

[0098] R5: The radius of curvature of the object surface S5 of the third lens L3;

[0099] R6: Radius of curvature of the image-side surface S6 of the third lens L3;

[0100] R7: The radius of curvature of the object surface S7 of the fourth lens L4;

[0101] R8: Radius of curvature of the image-side surface S8 of the fourth lens L4;

[0102] R9: The radius of curvature of the object surface S9 of the fifth lens L5;

[0103] R10: Radius of curvature of the image-side surface S10 of the fifth lens L5;

[0104] R11: The radius of curvature of the object surface S11 of the sixth lens L6;

[0105] R12: Radius of curvature of the image-side surface S12 of the sixth lens L6;

[0106] R13: Radius of curvature of the surface S13 of the glass plate GF;

[0107] R14: Radius of curvature of the image side surface S14 of the glass plate GF;

[0108] d: Axial thickness of the lens, or axial distance between lenses;

[0109] d0: The on-axis distance from the aperture STOP to the object-side surface S1 of the first lens L1;

[0110] d1: On-axis thickness of the first lens L1;

[0111] d2: The on-axis distance from the image-side surface S2 of the first lens L1 to the object-side surface S3 of the second lens L2;

[0112] d3: On-axis thickness of the second lens L2;

[0113] d4: The on-axis distance from the image-side surface S4 of the second lens L2 to the object-side surface S5 of the third lens L3;

[0114] d5: On-axis thickness of the third lens L3;

[0115] d6: The on-axis distance from the image-side surface S6 of the third lens L3 to the object-side surface S7 of the fourth lens L4;

[0116] d7: On-axis thickness of the fourth lens L4;

[0117] d8: The on-axis distance from the image-side surface S8 of the fourth lens L4 to the object-side surface S9 of the fifth lens L5;

[0118] d9: On-axis thickness of the fifth lens L5;

[0119] d10: The on-axis distance from the image-side surface S10 of the fifth lens L5 to the object-side surface S11 of the sixth lens L6;

[0120] d11: On-axis thickness of the sixth lens L6;

[0121] d12: The on-axis distance from the image-side surface S12 of the sixth lens L6 to the object-side surface S13 of the glass plate GF;

[0122] d13: Axial thickness of the glass plate GF;

[0123] d14: The on-axis distance from the image-side surface S14 of the glass plate GF to the image plane;

[0124] D12: The on-axis distance from the object-side surface S1 of the first lens L1 to the image-side surface S4 of the second lens L2;

[0125] nd: Refractive index of the d-line;

[0126] nd1: The refractive index of the d-line of the first lens L1;

[0127] nd2: The refractive index of the d-line of the second lens L2;

[0128] nd3: The refractive index of the d-line of the third lens L3;

[0129] nd4: The refractive index of the d-line of the fourth lens L4;

[0130] nd5: The refractive index of the d-line of the fifth lens L5;

[0131] nd6: The refractive index of the d-line of the sixth lens L6;

[0132] ndg: The refractive index of the d-line of the glass plate GF;

[0133] νd: Abbe number;

[0134] ν1: The Abbe number of the first lens L1;

[0135] ν2: The Abbe number of the second lens L2;

[0136] ν3: Abbe number of the third lens L3;

[0137] ν4: Abbe number of the fourth lens L4;

[0138] ν5: Abbe number of the fifth lens L5;

[0139] ν6: Abbe number of the sixth lens L6;

[0140] νg: Abbe number of the glass plate GF;

[0141] TTL: Total optical length (the axial distance from the object surface S1 of the first lens L1 to the image plane);

[0142] LB: Back focal length (the on-axis distance from the image-side surface S12 of the sixth lens L6 to the image plane);

[0143] IH: High.

[0144] (Example 1)

[0145] Figure 1 This is a structural diagram showing the configuration of the camera lens LA in Embodiment 1 during imaging and during retraction. Table 1 shows the radius of curvature R of each object-side and image-side surface of the first lens L1 to the sixth lens L6 constituting the camera lens LA of Embodiment 1, the on-axis thickness of the lens or the on-axis distance between lenses d, the refractive index nd, and the Abbe number νd. Table 2 shows the values ​​of A during imaging and during retraction. Table 3 shows the conic coefficient k and the aspherical coefficient. Table 4 shows 2ω, Fno, f, f1, f2, f3, f4, f5, f6, TTL, and IH.

[0146] Table 1

[0147]

[0148] Reference wavelength = 588nm

[0149] Table 2

[0150] A 4.503 0.500

[0151] Table 3

[0152]

[0153]

[0154] Where k is the conic coefficient, and A4, A6, A8, A10, A12, A14, A16, A18, and A20 are the aspheric coefficients.

[0155] y = (x 2 / R) / [1+{1-(k+1)(x 2 / R 2 )} 1 / 2 ]+A4x 4 +A6x 6 +A8x 8 +A10x 10 +A12x 12 +A14x 14 +A16x 16 +A18x 18 +A20x 20 (9)

[0156] Where x is the perpendicular distance between a point on the aspherical curve and the optical axis, and y is the aspherical depth (the perpendicular distance between a point on the aspherical surface at a distance x from the optical axis and a tangent plane at the vertex of the aspherical optical axis).

[0157] For convenience, the aspherical surfaces of each lens surface are those shown in formula (9) above. However, the present invention is not particularly limited to the aspherical polynomial form represented by formula (9).

[0158] Table 4

[0159] Fno 2.40 f (mm) 11.500 f1 (mm) 9.143 f2 (mm) 14.893 f3 (mm) -7.993 f4 (mm) -95.634 f5 (mm) 32.829 f6 (mm) -53.288 TTL at photographing (mm) 11.004 TTL at retraction (mm) 7.001 IH (mm) 5.120 TTL at photographing / IH 2.149 TTL at retraction / IH 1.367

[0160] Table 13, which appears later, shows the values ​​of the parameters in each of Examples 1 to 3 that correspond to the parameters specified in Relations (1) to (8).

[0161] As shown in Table 13, Example 1 satisfies relations (1) to (8).

[0162] Figure 2 The figure shows the axial spherical aberration, astigmatism, field curvature, and distortion of the camera lens LA in Embodiment 1. It should be noted that the field curvature S in the figure is relative to the sagittal image plane, and T is relative to the tangential image plane; this is also the case in Embodiments 2 and 3. It can be seen that the camera lens LA in Embodiment 1 has a narrow angle of 2ω = 47.24°, and when the TTL / IH is 1.367 at contraction, it has a low height at contraction, and as... Figure 2 As shown, it has excellent optical properties.

[0163] (Example 2)

[0164] Figure 3 This is a structural diagram showing the configuration of the camera lens LA in Embodiment 2 during imaging and during retraction. Table 5 shows the radius of curvature R of each object side and image side of the first lens L1 to the sixth lens L6 constituting the camera lens LA in Embodiment 2, the axial thickness of the lens or the axial distance between lenses d, the refractive index nd, and the Abbe number νd. Table 6 shows the values ​​of A during imaging and during retraction. Table 7 shows the conic coefficient k and the aspherical coefficient. Table 8 shows 2ω, Fno, f, f1, f2, f3, f4, f5, f6, TTL, and IH.

[0165] Table 5

[0166]

[0167]

[0168] Reference wavelength = 588nm

[0169] Table 6

[0170] A 4.502 0.500

[0171] Table 7

[0172]

[0173]

[0174] Table 8

[0175] Fno 2.40 f (mm) 11.500 f1 (mm) 6.958 f2 (mm) 10.408 f3 (mm) -5.808 f4 (mm) -50.423 f5 (mm) 32.487 f6 (mm) -26.737 TTL at photographing (mm) 10.994 TTL at retraction (mm) 6.992 IH (mm) 5.120 TTL at photographing / IH 2.147 TTL at retraction / IH 1.366

[0176] As shown in Table 13, Example 2 satisfies relations (1) to (8).

[0177] Figure 4The diagram shows the axial spherical aberration, astigmatism, and distortion of the camera lens LA in Example 2. It can be seen that the camera lens LA in Example 2 has a narrow angle of 2ω = 47.21°, and when the TTL / IH is 1.366 at retraction, it has a low height at retraction, and as... Figure 4 As shown, it has excellent optical properties.

[0178] (Example 3)

[0179] Figure 5 This is a structural diagram showing the configuration of the camera lens LA in Embodiment 3 during imaging and during retraction. Table 9 shows the radius of curvature R of each object side and image side of the first lens L1 to the sixth lens L6 constituting the camera lens LA in Embodiment 3, the on-axis thickness of the lens or the on-axis distance between lenses d, the refractive index nd, and the Abbe number νd. Table 10 shows the values ​​of A during imaging and during retraction. Table 11 shows the conic coefficient k and the aspherical coefficient. Table 12 shows 2ω, Fno, f, f1, f2, f3, f4, f5, f6, TTL, and IH.

[0180] Table 9

[0181]

[0182] Reference wavelength = 588nm

[0183] Table 10

[0184] A 4.498 0.500

[0185] Table 11

[0186]

[0187]

[0188] Table 12

[0189]

[0190]

[0191] As shown in Table 13, Example 3 satisfies relations (1) to (8).

[0192] Figure 6 The diagram shows the axial spherical aberration, astigmatism, and distortion of the camera lens LA in Example 3. It can be seen that the camera lens LA in Example 3 has a narrow angle of 2ω = 47.24°, and when the TTL / IH is 1.366 at retraction, it has a low height at retraction, and as... Figure 6 As shown, it has excellent optical properties.

[0193] Table 13 shows the values ​​of the parameters in Examples 1 to 3 that are specified in Relations (1) to (8).

[0194] Table 13

[0195] TTL at photographing / LB 2.195 2.193 2.195 Formula (1) D12 / d2 8.495 7.505 8.000 Formula (2) d6 / f 0.075 0.045 0.060 Formula (3) R6 / R7 -0.995 -0.355 -0.675 Formula (4) f1 / f 0.795 0.605 0.700 Formula (5) f2 / f 1.295 0.905 1.100 Formula (6) f3 / f -0.695 -0.505 -0.600 Formula (7) d8 / f 0.095 0.055 0.075 Formula (8)

[0196] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A camera lens, characterized in that, The camera lens comprises a first lens with positive refractive power, a second lens with positive refractive power, a third lens with negative refractive power, a fourth lens with negative refractive power, a fifth lens with positive refractive power, and a sixth lens with negative refractive power, arranged sequentially from the object side to the image side. The object side and image side of the first lens are convex and concave, respectively; the object side of the second lens is convex; the object side and image side of the third lens are both concave; the object side of the fourth lens is concave; the object side and image side of the fifth lens are concave and convex, respectively; and the object side and image side of the sixth lens are convex and concave, respectively. Wherein, the total optical length of the camera lens is TTL, the back focal length of the camera lens is LB, the axial distance from the object side of the first lens to the image side of the second lens is D12, the axial distance from the image side of the first lens to the object side of the second lens is d2, the overall focal length of the camera lens is f, the axial distance from the image side of the third lens to the object side of the fourth lens is d6, the radius of curvature of the image side of the third lens is R6, the radius of curvature of the object side of the fourth lens is R7, and the following relationships (1)~(4) are satisfied: TTL / LB during photography ≤ 2.20 (1) 7.50≤D12 / d2≤8.50(2) 0.04≤d6 / f≤0.08(3) -1.00≤R6 / R7≤-0.35(4).

2. The camera lens according to claim 1, characterized in that, The focal length of the first lens is f1, and it satisfies the following relationship (5): 0.60≤f1 / f≤0.80(5).

3. The camera lens according to claim 1, characterized in that, The focal length of the second lens is f2, and it satisfies the following relationship (6): 0.90≤f2 / f≤1.30(6).

4. The camera lens according to claim 1, characterized in that, The focal length of the third lens is f3, and it satisfies the following relationship (7): -0.70≤f3 / f≤-0.50(7).

5. The camera lens according to claim 1, characterized in that, The axial distance from the image side of the fourth lens to the object side of the fifth lens is d8, and satisfies the following relationship (8): 0.05≤d8 / f≤0.10(8).

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