Camera lens

Abstract

The present invention provides a camera lens, which can meet the requirements of low back and low F value and has good optical characteristics. The camera lens comprises, from the object side to the image side, a first lens, whose convex surface in the paraxial area faces the object side and has positive optical power; a second lens, whose convex surface in the paraxial area faces the object side and has negative optical power; a third lens, whose convex surface in the paraxial area faces the object side and has negative optical power; a fourth lens; and a fifth lens, whose convex surface in the paraxial area faces the image side; and a predetermined conditional formula is satisfied.

Description

Technical Field

[0001] The present invention relates to an imaging lens for forming an image of a subject on a solid-state imaging element of a CCD sensor or a C-MOS sensor used in an imaging device. Background Art

[0002] In recent years, camera functions have been widely installed in various products such as home appliances, information terminals, and automobiles. It is expected that the development of products incorporating camera functions will continue in the future.

[0003] The imaging lens installed in such equipment needs to be compact and have high resolution performance.

[0004] As an imaging lens that aims at improving performance in the related art, for example, an imaging lens disclosed in Patent Document 1 below is known.

[0005] Patent document 1 (China Patent Gazette No. 109298514) discloses a camera lens, which includes, from the object side, in sequence: a first lens having positive optical focal power; a second lens having optical focal power; a third lens having a concave surface facing the object side and a convex surface facing the image side, and having negative optical focal power; a fourth lens having a convex surface facing the object side and a concave surface facing the image side, and having optical focal power; and a fifth lens having optical focal power; the relationship between the focal length of the third lens and the focal length of the entire system satisfies certain conditions. Summary of the invention

[0006] Problem that the invention aims to solve

[0007] When attempting to achieve low profile and low F value by using the lens structure described in Patent Document 1, it is very difficult to correct aberrations in the peripheral portion, and good optical performance cannot be obtained.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an imaging lens having a high resolution that satisfies the requirements for low profile and low F-number in a balanced manner and that satisfies various aberrations with good correction.

[0009] Furthermore, regarding the terms used in the present invention, the convex surface, concave surface, and plane surface of the lens surface refer to the shape near the optical axis (paraxial). The optical power refers to the optical power near the optical axis (paraxial). The pole refers to the point on the aspheric surface other than the optical axis where the tangent plane intersects the optical axis perpendicularly. The total optical length refers to the distance on the optical axis from the object side of the optical element located closest to the object side to the imaging surface. In addition, the total optical length and the back focal length are distances obtained by converting the thickness of the IR cutoff filter or protective glass disposed between the imaging lens and the imaging surface into air.

[0010] Means used to solve problems

[0011] The camera lens of the present invention comprises, from the object side to the image side, a first lens having a positive optical focal length in a paraxial region with a convex surface facing the object side; a second lens having a negative optical focal length in a paraxial region with a convex surface facing the object side; a third lens having a negative optical focal length in the paraxial region; a fourth lens; and a fifth lens having a convex surface facing the image side in the paraxial region.

[0012] By increasing the optical power, the first lens element can be made low profile. In addition, by making the convex surface of the paraxial region face the object side, spherical aberration and distortion can be suppressed.

[0013] The second lens element can well correct spherical aberration and chromatic aberration. In addition, since the convex surface of the second lens element is toward the object side in the paraxial region, coma, astigmatism and distortion can be well corrected.

[0014] The third lens well corrects chromatic aberration, coma, astigmatism, and distortion.

[0015] The fourth lens well corrects astigmatism, field curvature and distortion.

[0016] The fifth lens can well correct astigmatism, field curvature and distortion. In addition, by making the convex surface in the paraxial zone toward the image side, the incident angle of light to the imaging element can be properly controlled. As a result, the lens diameter of the fifth lens can be reduced, and the diameter of the imaging lens can be reduced.

[0017] In addition, in the imaging lens of the above structure, it is preferred that the object-side surface of the third lens be concave toward the object side in the paraxial region.

[0018] By making the object-side surface of the third lens element concave toward the object side in the paraxial region, astigmatism and distortion can be corrected well.

[0019] In the imaging lens having the above configuration, it is preferred that the image-side surface of the third lens be concave toward the image side in the paraxial region.

[0020] By making the image-side surface of the third lens element concave toward the image side in the paraxial region, coma, astigmatism and distortion can be corrected well.

[0021] In the imaging lens of the above structure, it is preferred that the object-side surface of the fourth lens element is concave toward the object side in the paraxial region.

[0022] By making the object-side surface of the fourth lens element concave toward the object side in the paraxial region, astigmatism and distortion can be corrected well.

[0023] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (1) is satisfied:

[0024] (1) -0.95<r2 / r3 / |r8|<-0.25

[0025] in,

[0026] r2: paraxial radius of curvature of the image side of the first lens,

[0027] r3: the paraxial radius of curvature of the object side of the second lens,

[0028] r8: paraxial radius of curvature of the image-side surface of the fourth lens.

[0029] Conditional formula (1) specifies the relationship between the paraxial curvature radius of the image side surface of the first lens, the paraxial curvature radius of the object side surface of the second lens, and the paraxial curvature radius of the image side surface of the fourth lens within an appropriate range. By satisfying conditional formula (1), spherical aberration, coma, astigmatism, field curvature, and distortion can be well corrected.

[0030] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (2) is satisfied:

[0031] (2)-10.00<(D3 / f3)×100<-2.50

[0032] in,

[0033] D3: The thickness of the third lens on the optical axis,

[0034] f3: focal length of the third lens.

[0035] Conditional expression (2) specifies the relationship between the thickness of the third lens on the optical axis and the focal length of the third lens within an appropriate range. By satisfying the range of conditional expression (2), low profile can be achieved, the focal power of the third lens becomes an appropriate value, and chromatic aberration, coma, astigmatism and distortion can be well corrected.

[0036] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (3) is satisfied:

[0037] (3) -1.35<f4 / f5<-0.55

[0038] in,

[0039] f4: focal length of the fourth lens,

[0040] f5: Focal length of the fifth lens.

[0041] Conditional equation (3) specifies the relationship between the focal length of the fourth lens and the focal length of the fifth lens within an appropriate range. By satisfying the range of conditional equation (3), the focal power of the fourth lens and the focal power of the fifth lens can be appropriately balanced. As a result, astigmatism, field curvature, and distortion can be well corrected.

[0042] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (4) is satisfied:

[0043] (4)1.65<T2 / T1<4.50

[0044] in,

[0045] T2: The distance on the optical axis from the image side of the second lens to the object side of the third lens.

[0046] T1: The distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens.

[0047] Conditional formula (4) specifies the relationship between the distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens and the distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens within an appropriate range. By satisfying the range of conditional formula (4), the second lens is configured at the optimal position, making the various aberration correction functions of the lens more effective. As a result, low-profile can be achieved, and coma, astigmatism and distortion can be corrected well.

[0048] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (5) is satisfied:

[0049] (5)-3.75<r3 / r10<-1.00

[0050] in,

[0051] r3: the paraxial radius of curvature of the object side of the second lens,

[0052] r10: paraxial curvature radius of the image-side surface of the fifth lens.

[0053] The conditional expression (5) specifies the relationship between the paraxial curvature radius of the object side surface of the second lens and the paraxial curvature radius of the image side surface of the fifth lens within an appropriate range. By satisfying the range of the conditional expression (5), coma, astigmatism, field curvature and distortion can be well corrected.

[0054] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (6) is satisfied:

[0055] (6)0.10<|r8| / f<2.50

[0056] in,

[0057] r8: paraxial curvature radius of the image side of the fourth lens,

[0058] f: Focal length of the entire camera lens system.

[0059] Conditional expression (6) specifies the paraxial curvature radius of the image-side surface of the fourth lens within an appropriate range. By satisfying the range of conditional expression (6), astigmatism, field curvature, and distortion can be corrected well.

[0060] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (7) is satisfied:

[0061] (7) -2.70<r10 / r4<-0.50

[0062] in,

[0063] r10: paraxial radius of curvature of the image side of the fifth lens,

[0064] r4: paraxial radius of curvature of the image-side surface of the second lens.

[0065] Conditional expression (7) specifies the relationship between the paraxial curvature radius of the image side surface of the fifth lens and the paraxial curvature radius of the image side surface of the second lens within an appropriate range. By satisfying the range of conditional expression (7), coma, astigmatism, field curvature and distortion can be well corrected.

[0066] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (8) is satisfied:

[0067] (8)10.00<νd2<30.00

[0068] in,

[0069] νd2: Abbe number of the second lens with respect to the d-line.

[0070] Conditional expression (8) defines the Abbe coefficient of the second lens with respect to the d-line within an appropriate range. When the range of conditional expression (8) is satisfied, chromatic aberration can be corrected well.

[0071] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (9) is satisfied:

[0072] (9) 0.30<(T4 / f)×100<1.55

[0073] in,

[0074] T4: The distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens,

[0075] f: Focal length of the entire camera lens system.

[0076] Conditional expression (9) specifies the distance on the optical axis from the image side surface of the fourth lens to the object side surface of the fifth lens within an appropriate range. By satisfying the range of conditional expression (9), a low profile can be achieved, and astigmatism and distortion can be corrected well.

[0077] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (10) is satisfied:

[0078] (10)-3.00<(r2 / T1) / 100<-0.25

[0079] in,

[0080] r2: paraxial radius of curvature of the image side of the first lens,

[0081] T1: The distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens.

[0082] Conditional formula (10) specifies the relationship between the paraxial curvature radius of the image side surface of the first lens and the distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens within an appropriate range. By satisfying the range of conditional formula (10), low-profile lens can be achieved, and coma, astigmatism and distortion can be well corrected.

[0083] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (11) is satisfied:

[0084] (11) 0.05<r2 / r5<14.00

[0085] in,

[0086] r2: paraxial radius of curvature of the image side of the first lens,

[0087] r5: paraxial radius of curvature of the object side of the third lens.

[0088] Conditional expression (11) specifies the relationship between the paraxial curvature radius of the image side surface of the first lens and the paraxial curvature radius of the object side surface of the third lens within an appropriate range. By satisfying the range of conditional expression (11), coma, astigmatism and distortion can be corrected well.

[0089] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (12) is satisfied:

[0090] (12)-5.00<r3 / r7<-0.75

[0091] in,

[0092] r3: the paraxial radius of curvature of the object side of the second lens,

[0093] r7: paraxial radius of curvature of the object side of the fourth lens.

[0094] Conditional expression (12) defines the relationship between the paraxial curvature radius of the object side surface of the second lens and the paraxial curvature radius of the object side surface of the fourth lens within an appropriate range. By satisfying conditional expression (12), coma, astigmatism, and distortion can be corrected well.

[0095] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (13) is satisfied:

[0096] (13)-100.0<r5 / T3<-1.00

[0097] in,

[0098] r5: the paraxial radius of curvature of the object side of the third lens,

[0099] T3: The distance on the optical axis from the image side surface of the third lens to the object side surface of the fourth lens.

[0100] Conditional formula (13) specifies the relationship between the paraxial curvature radius of the object side surface of the third lens and the distance on the optical axis from the image side surface of the third lens to the object side surface of the fourth lens within an appropriate range. By satisfying the range of conditional formula (13), low profile can be achieved, and astigmatism and distortion can be well corrected.

[0101] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (14) is satisfied:

[0102] (14)-22.50<r7 / T2<-6.50

[0103] in,

[0104] r7: the paraxial radius of curvature of the object side of the fourth lens,

[0105] T2: The distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens.

[0106] Conditional formula (14) specifies the relationship between the paraxial curvature radius of the object side surface of the fourth lens and the distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens within an appropriate range. By satisfying the range of conditional formula (14), low profile can be achieved, and astigmatism and distortion can be well corrected.

[0107] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (15) is satisfied:

[0108] (15)-10.00<r7 / (T3-T2)<-2.00

[0109] in,

[0110] r7: the paraxial radius of curvature of the object side of the fourth lens,

[0111] T3: The distance on the optical axis from the image side of the third lens to the object side of the fourth lens.

[0112] T2: The distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens.

[0113] Conditional formula (15) specifies the relationship between the paraxial curvature radius of the object side surface of the fourth lens, the distance on the optical axis from the image side surface of the third lens to the object side surface of the fourth lens, and the distance on the optical axis from the image side surface of the second lens to the object side surface of the third lens within an appropriate range. By satisfying the range of conditional formula (15), the focal length of the object side surface of the fourth lens can be maintained, and the third lens is configured in the optimal position, so that the various aberration correction functions of the lens become more effective. As a result, low-profile can be achieved, and coma, astigmatism and distortion can be corrected well.

[0114] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (16) is satisfied:

[0115] (16)-1.30<r10 / f<-0.10

[0116] in,

[0117] r10: paraxial radius of curvature of the image side of the fifth lens,

[0118] f: Focal length of the entire camera lens system.

[0119] Conditional expression (16) specifies the paraxial curvature radius of the image-side surface of the fifth lens within an appropriate range. By satisfying the range of conditional expression (16), field curvature and distortion can be corrected well.

[0120] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (17) is satisfied:

[0121] (17) -1.65<f3 / f<-0.40

[0122] in,

[0123] f3: focal length of the third lens,

[0124] f: Focal length of the entire camera lens system.

[0125] Conditional expression (17) specifies the focal length of the third lens within an appropriate range. When the conditional expression (17) is satisfied, the negative refractive power of the third lens becomes an appropriate value, and chromatic aberration, coma, astigmatism, and distortion can be corrected well.

[0126] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (18) is satisfied:

[0127] (18)0.60<|f4| / f<2.00

[0128] in,

[0129] f4: focal length of the fourth lens,

[0130] f: Focal length of the entire camera lens system.

[0131] Conditional expression (18) specifies the focal length of the fourth lens within an appropriate range. By satisfying the range of conditional expression (18), astigmatism, field curvature, and distortion can be corrected well.

[0132] In addition, in the imaging lens of the above structure, it is preferable that the following conditional expression (19) is satisfied:

[0133] (19)-18.00<(D2 / f2)×100<-1.50

[0134] in,

[0135] D2: The thickness of the second lens on the optical axis,

[0136] f2: Focal length of the second lens.

[0137] Conditional expression (19) specifies the relationship between the thickness of the second lens on the optical axis and the focal length of the second lens within an appropriate range. By satisfying the range of conditional expression (19), low profile can be achieved, the optical power of the second lens becomes an appropriate value, and chromatic aberration, coma, astigmatism and distortion can be well corrected.

[0138] Effects of the Invention

[0139] According to the present invention, it is possible to obtain an imaging lens that satisfies the requirements of low profile and low F value in a balanced manner, corrects various aberrations well, and has high resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0140] Figure 1 It is a diagram showing a schematic structure of an imaging lens according to Example 1 of the present invention.

[0141] Figure 2 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 1 of the present invention.

[0142] Figure 3 A diagram schematically showing the structure of an imaging lens according to Example 2 of the present invention.

[0143] Figure 4 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 2 of the present invention.

[0144] Figure 5 A diagram schematically showing the structure of an imaging lens according to Example 3 of the present invention.

[0145] Figure 6 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 3 of the present invention.

[0146] Figure 7A diagram schematically showing the structure of an imaging lens according to Example 4 of the present invention.

[0147] Figure 8 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 4 of the present invention.

[0148] Fig. 9 A diagram schematically showing the structure of an imaging lens according to Example 5 of the present invention.

[0149] Fig.10 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 5 of the present invention.

[0150] Fig.11 A diagram schematically showing the structure of an imaging lens according to Example 6 of the present invention.

[0151] Fig.12 These are diagrams showing spherical aberration, astigmatism, and distortion of the imaging lens according to Example 6 of the present invention.

[0152] Description of Reference Numerals

[0153] ST: Aperture stop,

[0154] L1: First lens,

[0155] L2: Second lens,

[0156] L3: The third lens,

[0157] L4: The fourth lens,

[0158] L5: The fifth lens,

[0159] ih: maximum image height,

[0160] IR: Filter,

[0161] IMG: Camera side. DETAILED DESCRIPTION

[0162] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0163] Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 and Fig.11 The following are schematic diagrams of the configurations of imaging lenses according to Examples 1 to 6 of the embodiments of the present invention.

[0164] The camera lens of this embodiment includes, from the object side to the image side, in order: a first lens L1, with a convex surface in the paraxial zone facing the object side and having positive optical focal length; a second lens L2, with a convex surface in the paraxial zone facing the object side and having negative optical focal length; a third lens L3, with negative optical focal length in the paraxial zone; a fourth lens L4; and a fifth lens L5, with a convex surface in the paraxial zone facing the image side.

[0165] An infrared cut filter, a protective glass or other filter IR is disposed between the fifth lens L5 and the imaging plane IMG (ie, the imaging plane of the imaging element). The filter IR may be omitted.

[0166] By arranging the aperture stop ST on the object side of the first lens L1, various aberrations can be easily corrected, and the incident angle of light with a high image height onto the imaging element can be easily controlled.

[0167] The first lens L1 has positive refractive power and is biconvex in shape with a convex surface facing the object side and a convex surface facing the image side in the paraxial region. Therefore, by enhancing the refractive power, a low profile is achieved and spherical aberration and distortion are suppressed.

[0168] The second lens L2 has negative refractive power and has a meniscus shape with a convex surface facing the object side and a concave surface facing the image side in a paraxial region, so spherical aberration, chromatic aberration, coma, astigmatism and distortion are well corrected.

[0169] The third lens L3 has negative refractive power and has a biconcave shape with a concave surface facing the object side and a concave surface facing the image side in the paraxial region, so chromatic aberration, coma, astigmatism and distortion are well corrected.

[0170] The fourth lens L4 has negative refractive power and has a biconcave shape with a concave surface facing the object side and a concave surface facing the image side in the paraxial region, so astigmatism, field curvature and distortion are well corrected.

[0171] In addition, if Figure 3 , Figure 5 , Figure 7 , Fig. 9 and Fig.11 As shown in Examples 2, 3, 4, 5 and 6, the shape of the fourth lens L4 may also be a meniscus shape with a concave surface facing the object side and a convex surface facing the image side in the paraxial region. In this case, the incident angle of light to the fourth lens L4 can be properly controlled, and astigmatism and distortion can be well corrected.

[0172] In addition, if Figure 3 , Figure 5 , Figure 7 , Fig. 9 and Fig.11 As shown in Examples 2, 3, 4, 5 and 6, the refractive power of the fourth lens L4 may be a positive value. In this case, it is advantageous for achieving a low profile.

[0173] The fifth lens L5 has positive optical power and is in a biconvex shape with the convex surface facing the object side in the paraxial zone and the convex surface facing the image side. Therefore, by enhancing the optical power, low profile is achieved, and astigmatism, field curvature and distortion are well corrected. In addition, by facing the convex surface in the paraxial zone to the image side, the incident angle of light to the imaging element is appropriately controlled. As a result, the lens diameter of the fifth lens L5 can be reduced, and the diameter of the imaging lens can be reduced.

[0174] In addition, if Figure 3 , Figure 5 , Figure 7 , Fig. 9 and Fig.11 As shown in Examples 2, 3, 4, 5 and 6, the shape of the fifth lens L5 may also be a meniscus shape with a concave surface facing the object side and a convex surface facing the image side in the paraxial region. In this case, the incident angle of light to the fifth lens L5 can be properly controlled, and astigmatism and distortion can be well corrected.

[0175] In addition, if Figure 3 , Figure 5 , Figure 7 , Fig. 9 and Fig.11 As shown in Examples 2, 3, 4, 5 and 6, the refractive power of the fifth lens L5 may be set to a negative value. In this case, it is advantageous to correct chromatic aberration.

[0176] In the camera lens of this embodiment, it is preferred that all lenses from the first lens L1 to the fifth lens L5 are composed of respective single lenses. Composed of only single lenses, more aspheric surfaces can be used. In this embodiment, by forming all lens surfaces into appropriate aspheric surfaces, various aberrations can be corrected well. In addition, compared with the case of using a cemented lens, since the man-hours can be reduced, it can be manufactured at a low cost.

[0177] Furthermore, the imaging lens of this embodiment uses plastic material for all lenses, so that the manufacturing is easy and mass production is possible at low cost.

[0178] In addition, the lens material used is not limited to plastic materials. By adopting glass materials, higher performance can also be expected. In addition, it is preferred that all lens surfaces are formed as aspherical surfaces, but spherical surfaces that are easy to manufacture can also be adopted according to the required performance.

[0179] The imaging lens in this embodiment satisfies the following conditional expressions (1) to (19), thereby achieving favorable effects.

[0180] (1) -0.95<r2 / r3 / |r8|<-0.25

[0181] (2)-10.00<(D3 / f3)×100<-2.50

[0182] (3) -1.35<f4 / f5<-0.55

[0183] (4)1.65<T2 / T1<4.50

[0184] (5)-3.75<r3 / r10<-1.00

[0185] (6)0.10<|r8| / f<2.50

[0186] (7) -2.70<r10 / r4<-0.50

[0187] (8)10.00<νd2<30.00

[0188] (9) 0.30<(T4 / f)×100<1.55

[0189] (10)-3.00<(r2 / T1) / 100<-0.25

[0190] (11) 0.05<r2 / r5<14.00

[0191] (12)-5.00<r3 / r7<-0.75

[0192] (13)-100.0<r5 / T3<-1.00

[0193] (14)-22.50<r7 / T2<-6.50

[0194] (15)-10.00<r7 / (T3-T2)<-2.00

[0195] (16)-1.30<r10 / f<-0.10

[0196] (17) -1.65<f3 / f<-0.40

[0197] (18)0.60<|f4| / f<2.00

[0198] (19)-18.00<(D2 / f2)×100<-1.50

[0199] in,

[0200] νd2: Abbe number of the second lens L2 with respect to the d-line,

[0201] D2: thickness of the second lens L2 on the optical axis X,

[0202] D3: thickness of the third lens L3 on the optical axis X,

[0203] T1: The distance on the optical axis X from the image side surface of the first lens L1 to the object side surface of the second lens L2,

[0204] T2: the distance on the optical axis X from the image side surface of the second lens L2 to the object side surface of the third lens L3,

[0205] T3: the distance on the optical axis X from the image side surface of the third lens L3 to the object side surface of the fourth lens L4,

[0206] T4: the distance on the optical axis X from the image side surface of the fourth lens L4 to the object side surface of the fifth lens L5,

[0207] f: focal length of the entire camera lens system,

[0208] f2: focal length of the second lens L2,

[0209] f3: focal length of the third lens L3,

[0210] f4: focal length of the fourth lens L4,

[0211] f5: focal length of the fifth lens L5,

[0212] r2: paraxial curvature radius of the image side surface of the first lens L1,

[0213] r3: the paraxial radius of curvature of the object side of the second lens L2,

[0214] r4: paraxial curvature radius of the image side surface of the second lens L2,

[0215] r5: paraxial radius of curvature of the object side of the third lens L3,

[0216] r7: paraxial radius of curvature of the object side of the fourth lens L4,

[0217] r8: paraxial curvature radius of the image side surface of the fourth lens L4,

[0218] r10: paraxial curvature radius of the image-side surface of the fifth lens L5.

[0219] It is not necessary to satisfy all of the above-mentioned conditional expressions, and by satisfying each conditional expression individually, an action and effect corresponding to each conditional expression can be obtained.

[0220] Furthermore, the imaging lens in this embodiment satisfies the following conditional expressions (1a) to (19a), thereby achieving better effects.

[0221] (1a)-0.80<r2 / r3 / |r8|<-0.28

[0222] (2a)-7.50<(D3 / f3)×100<-2.80

[0223] (3a) -1.10<f4 / f5<-0.63

[0224] (4a)1.85<T2 / T1<3.80

[0225] (5a)-3.35<r3 / r10<-1.25

[0226] (6a) 0.20<|r8| / f<2.00

[0227] (7a)-2.50<r10 / r4<-0.90

[0228] (8a)14.50<νd2<25.00

[0229] (9a) 0.50<(T4 / f)×100<1.25

[0230] (10a)-2.30<(r2 / T1) / 100<-0.45

[0231] (11a) 0.08<r2 / r5<11.50

[0232] (12a)-4.00<r3 / r7<-0.90

[0233] (13a)-80.0<r5 / T3<-1.50

[0234] (14a)-19.00<r7 / T2<-7.00

[0235] (15a)-8.50<r7 / (T3-T2)<-2.50

[0236] (16a)-1.00<r10 / f<-0.35

[0237] (17a)-1.35<f3 / f<-0.65

[0238] (18a)0.70<|f4| / f<1.70

[0239] (19a)-15.00<(D2 / f2)×100<-2.20

[0240] The symbols of each conditional expression are the same as those described in the previous paragraph.

[0241] In addition, the imaging lens in this embodiment satisfies the following conditional expression (19c), thereby achieving the best effect.

[0242] (19c)-13.50<(D2 / f2)×100<-8.50

[0243] The symbols of each conditional expression are the same as those described in the previous paragraph.

[0244] In this embodiment, the aspheric shape used on the aspheric surface of the lens surface is expressed by mathematical formula 1 when the axis in the optical axis direction is set to Z, the height in the direction perpendicular to the optical axis is set to H, the near-axis curvature radius is set to R, the cone coefficient is set to k, and the aspheric coefficient is set to A4, A6, A8, A10, A12, A14, A16, A18, and A20.

[0245] [Mathematical formula 1]

[0246]

[0247] Next, examples of the imaging lens involved in this embodiment are shown. In each example, f represents the focal length of the entire imaging lens system, Fno represents the F value, ω represents the half field angle, ih represents the maximum image height, and TTL represents the total optical length. In addition, i represents the surface number from the object side, r represents the paraxial curvature radius, d represents the distance between the lens surfaces on the optical axis (surface spacing), Nd represents the refractive index of the d-line (reference wavelength), and νd represents the dispersion coefficient relative to the d-line. In addition, for aspherical surfaces, the symbol * (asterisk) is added after the surface number i to represent it.

[0248] [Example 1]

[0249] Basic lens data are shown in Table 1 below.

[0250] [Table 1]

[0251] Example 1

[0252] Unit: mm

[0253] f=7.48

[0254] Fno=2.40

[0255] ω(°)=15.1

[0256] ih=2.04

[0257] TTL=6.36

[0258] Area data

[0259]

[0260] Composition lens data

[0261]

[0262] Aspheric surface data

[0263]

[0264] The imaging lens of Example 1 satisfies conditional expressions (1) to (19) as shown in Table 7.

[0265] Figure 2 The spherical aberration (mm), astigmatism (mm), and distortion (%) are shown for the imaging lens of Example 1. The spherical aberration diagram shows the aberration amount for each wavelength of the F line (486nm), d line (588nm), and C line (656nm). In addition, the astigmatism diagram shows the aberration amount of the d line on the sagittal image plane S (solid line) and the aberration amount of the d line on the meridional image plane T (dashed line). Figure 4 , Figure 6 , Figure 8 , Fig.10 and Fig.12 are the same in the examples. Figure 2 As shown, it can be seen that each aberration is well corrected.

[0266] [Example 2]

[0267] Basic lens data are shown in Table 2 below.

[0268] [Table 2]

[0269] Example 2

[0270] Unit: mm

[0271] f=7.48Fno=2.40

[0272] ω(°)=15.1

[0273] ih=2.04TTL=6.36Surface data

[0274] Composition lens data

[0275]

[0276] Aspheric surface data

[0277]

[0278] The imaging lens of Example 2 satisfies conditional expressions (1) to (19) as shown in Table 7.

[0279] Figure 4 For the imaging lens of Example 2, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Figure 4 As shown, it can be seen that each aberration is well corrected.

[0280] [Example 3]

[0281] Basic lens data are shown in Table 3 below.

[0282] [Table 3]

[0283] Example 3

[0284] Unit: mm

[0285] f=7.48

[0286] Fno=2.40

[0287] ω(°)=15.1

[0288] ih=2.04

[0289] TTL=6.36

[0290] Area data

[0291]

[0292] Composition lens data

[0293]

[0294] Aspheric surface data

[0295]

[0296] The imaging lens of Example 3 satisfies conditional expressions (1) to (19) as shown in Table 7.

[0297] Figure 6 For the imaging lens of Example 3, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Figure 6 As shown, it can be seen that each aberration is well corrected.

[0298] [Example 4]

[0299] Basic lens data are shown in Table 4 below.

[0300] [Table 4]

[0301] Example 4

[0302] Unit: mm

[0303] f=7.51

[0304] Fno=2.40

[0305] ω(°)=15.0

[0306] ih=2.04

[0307] TTL=6.36

[0308] Area data

[0309]

[0310] Composition lens data

[0311]

[0312] Aspheric surface data

[0313]

[0314] The imaging lens of Example 4 satisfies conditional expressions (1) to (19) as shown in Table 7.

[0315] Figure 8 For the imaging lens of Example 4, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Figure 8 As shown, it can be seen that each aberration is well corrected.

[0316] [Example 5]

[0317] Basic lens data are shown in Table 5 below.

[0318] [Table 5]

[0319] Example 5

[0320] Unit: mm

[0321] f=7.48

[0322] Fno=2.40

[0323] ω(°)=15.0

[0324] ih=2.04

[0325] TTL=6.36

[0326] Area data

[0327]

[0328] Composition lens data

[0329]

[0330] Aspheric surface data

[0331]

[0332] The imaging lens of Example 5 satisfies conditional expressions (1) to (19) as shown in Table 7.

[0333] Fig.10 For the imaging lens of Example 5, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig.10 As shown, it can be seen that each aberration is well corrected.

[0334] [Example 6]

[0335] Basic lens data are shown in Table 6 below.

[0336] [Table 6]

[0337] Example 6

[0338] Unit: mm

[0339] f=7.48

[0340] Fno=2.40

[0341] ω(°)=15.1

[0342] ih=2.04

[0343] TTL=6.36

[0344] Area data

[0345]

[0346] Composition lens data

[0347]

[0348] Aspheric surface data

[0349]

[0350] The imaging lens of Example 6 satisfies conditional expressions (1) to (19) as shown in Table 7.

[0351] Fig.12 For the imaging lens of Example 6, spherical aberration (mm), astigmatism (mm), and distortion (%) are shown. Fig.12 As shown, it can be seen that each aberration is well corrected.

[0352] Table 7 shows the values ​​of conditional expressions (1) to (19) according to Examples 1 to 6.

[0353] [Table 7]

[0354]

[0355] Industrial Applicability

[0356] When the imaging lens according to the present invention is applied to a product with a camera function, it can contribute to a lower profile and a lower F value of the camera, and can also achieve higher performance of the camera.

Claims

1. A camera lens, characterized in that: The total number of lenses with optical power in the camera lens is five, which include, from the object side to the image side: The first lens has a convex surface facing the object side in the paraxial region and has positive optical power; The second lens has a convex surface facing the object side in the paraxial region and has negative optical power; The third lens has an object side surface concave toward the object side in the paraxial region and an image side surface concave toward the image side in the paraxial region, and has negative optical power; a fourth lens; and The fifth lens has a convex surface facing the image side in the paraxial region; The following conditions (1), (2) and (3) are satisfied: (1)-0.95＜r2 / (r3×|r8|)＜-0.25 (2)-10.00<(D3 / f3)×100<-2.50 (3) -1.35<f4 / f5<-0.55 in, r2: paraxial radius of curvature of the image side of the first lens, r3: paraxial radius of curvature of the object side of the second lens, r8: paraxial curvature radius of the image side of the fourth lens, D3: The thickness of the third lens on the optical axis, f3: focal length of the third lens, f4: focal length of the fourth lens, f5: Focal length of the fifth lens.

2. The imaging lens according to claim 1, wherein: The object-side surface of the fourth lens element is concave toward the object side in the paraxial region.

3. The imaging lens according to claim 1, wherein: The following condition (4) is satisfied: (4)1.65<T2 / T1<4.50 in, T2: The distance on the optical axis from the image side of the second lens to the object side of the third lens. T1: The distance on the optical axis from the image side surface of the first lens to the object side surface of the second lens.

4. The imaging lens according to claim 1, wherein: The following condition (5) is satisfied: (5)-3.75＜r3 / r10＜-1.00 in, r3: paraxial radius of curvature of the object side of the second lens, r10: paraxial curvature radius of the image-side surface of the fifth lens.

5. The imaging lens according to claim 1, wherein: The following condition (6) is satisfied: (6)0.10＜|r8| / f＜2.50 in, r8: paraxial curvature radius of the image side of the fourth lens, f: Focal length of the entire camera lens system.

6. The imaging lens according to claim 1, wherein: The following condition (7) is satisfied: (7)-2.70＜r10 / r4＜-0.50 in, r10: paraxial radius of curvature of the image side of the fifth lens, r4: paraxial radius of curvature of the image-side surface of the second lens.

Images