Wide-angle lens

Abstract

Provided is a wide-angle lens that appropriately corrects various aberrations such as field curvature, magnification chromatic aberration, and coma, that achieves miniaturization of the wide-angle lens, and that suppresses ghosting between wide-angle lenses. A wide-angle lens (1000) includes a lens group in which a plurality of lenses are arranged in order from the object side in a manner that sandwiches an aperture (180), and the plurality of lenses include a first lens (110), a second lens (120), and a third lens (130) arranged in order from the object side, the image-side lens surface of the second lens (120) is a concave surface, and when half the length of the profile curve of the object-side lens surface of the third lens (130) is ARS31 and the effective radius of the object-side lens surface of the third lens (130) is sd31, the following relationship is satisfied: 1.0000 < ARS31 / sd31 < 1.0500.

Description

TECHNICAL FIELD

[0001] The present application relates to a wide-angle lens. BACKGROUND

[0002] As a lens mounted on a camera for vehicle or the like, there has been a wide-angle lens including a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens, and a seventh lens arranged in this order from an object side, wherein the sixth lens and the seventh lens constitute a cemented lens (for example, refer to Patent Literature 1).

[0003] Patent Literature 1: Japanese Patent Application Laid-Open No. 2018-60153

[0004] In practice, there are cases where it is necessary to downsize the camera for vehicle equipped with the above-described wide-angle lens, and in such cases, it is necessary to downsize the above-described wide-angle lens, but when the above-described wide-angle lens is downsized, it is easy to cause various aberrations to be hardly corrected, and it is difficult to suppress ghost caused by multiple reflection between lenses. SUMMARY

[0005] The present application has been made in view of the above-described problems, and has an object to provide a wide-angle lens capable of correcting various aberrations and suppressing ghost caused by multiple reflection between lenses.

[0006] To achieve the above-described object, the present application provides a wide-angle lens characterized by including a lens group and an aperture, a plurality of lenses in the lens group being arranged in this order from an object side with the aperture interposed therebetween, the plurality of lenses including a first lens, a second lens, and a third lens arranged in this order from the object side, an image-side lens surface of the second lens being a concave surface, and when a half of a length of a profile curve of an object-side lens surface of the third lens is set as ARS31 and an effective radius of the object-side lens surface of the third lens is set as sd31, the following relationship is satisfied: 1.0000 < ARS31 / sd31 < 1.0500, and more preferably, the following relationship is satisfied: 1.0000 < ARS31 / sd31 < 1.0200.

[0007] In the wide-angle lens according to the present application, when half the length of the profile curve of the object-side lens surface of the third lens is set as ARS31 and the effective radius of the object-side lens surface of the third lens is set as sd31, the relation ARS31 / sd31 > 1.0000 is satisfied, and therefore the object-side lens surface of the third lens is not flat, and thus various aberrations can be appropriately corrected. When half the length of the profile curve of the object-side lens surface of the third lens is set as ARS31 and the effective radius of the object-side lens surface of the third lens is set as sd31, the relation ARS31 / sd31 < 1.0500 is satisfied, and therefore the sag of the object-side lens surface of the third lens 130 will not be excessively large (deep), and thus ghosting (particularly, point-like ghosting) caused by multiple reflection between the image-side lens surface of the second lens and the object-side lens surface of the third lens can be suppressed.

[0008] Further, in the wide-angle lens according to the present application, when half the length of the profile curve of the image-side lens surface of the second lens is set as ARS22 and the effective radius of the image-side lens surface of the second lens is set as sd22, the following relation is satisfied: 1.2000 < ARS22 / sd22 < 1.5000.

[0009] In the wide-angle lens according to the present application, when half the length of the profile curve of the image-side lens surface of the second lens is set as ARS22 and the effective radius of the image-side lens surface of the second lens is set as sd22, the relation ARS22 / sd22 > 1.2000 is satisfied, and therefore the second lens can secure sufficient negative power, and various aberrations can be appropriately corrected. Further, when half the length of the profile curve of the image-side lens surface of the second lens is set as ARS22 and the effective radius of the image-side lens surface of the second lens is set as sd22, the relation ARS22 / sd22 < 1.5000 is satisfied, and therefore the angle of the periphery of the image-side lens surface of the second lens and the tangent can be prevented from being excessively small, and the second lens can be easily manufactured, and thus cost reduction can be achieved.

[0010] Further, in the wide-angle lens according to the present application, the third lens is a positive lens, and when the focal length of the third lens is set as f3 and the focal length of the entire wide-angle lens is set as f, the following relation is satisfied: 3.000 < f3 / f < 12.500, and more preferably the following relation is satisfied: 5.000 < f3 / f < 10.000.

[0011] In the wide-angle lens according to the present application, when a focal length of the third lens is set as f3 and a focal length of the entire wide-angle lens is set as f, a relation of f3 / f > 3.000 is satisfied, and thus, it is possible to avoid an excessive positive refractive power. Therefore, it is possible to appropriately correct various aberrations such as field curvature, lateral chromatic aberration, and coma, and it is possible to achieve excellent optical characteristics. Further, when the focal length of the third lens is set as f3 and the focal length of the entire wide-angle lens is set as f, a relation of f3 / f < 12.500 is satisfied, and it is possible to reduce a lens radius and an object-image distance, and thus, it is possible to achieve a reduction in size of the wide-angle lens.

[0012] Further, in the wide-angle lens according to the present application, the plurality of lenses include a fourth lens disposed adjacent to the third lens on the image side, the third lens is a positive lens, and the fourth lens is a positive lens. When a combined focal length of the third lens and the fourth lens is set as f34 and a focal length of the entire wide-angle lens is set as f, a relation of 2.000 < f34 / f < 5.000 is satisfied, and more preferably, a relation of 3.000 < f34 / f < 4.500 is satisfied.

[0013] In the wide-angle lens according to the present application, when a combined focal length of the third lens and the fourth lens is set as f34 and a focal length of the entire wide-angle lens is set as f, a relation of f34 / f > 2.000 is satisfied, and thus, it is possible to avoid an excessive positive refractive power. Therefore, it is possible to appropriately correct various aberrations such as field curvature, lateral chromatic aberration, and coma, and it is possible to achieve excellent optical characteristics. When the combined focal length of the third lens and the fourth lens is set as f34 and the focal length of the entire wide-angle lens is set as f, a relation of f34 / f < 5.000 is satisfied, and it is possible to reduce a lens radius and an object-image distance, and thus, it is possible to achieve a reduction in size of the wide-angle lens.

[0014] Further, in the wide-angle lens according to the present application, it is preferable that, when an object-image distance of the wide-angle lens is set as d and a focal length of the entire wide-angle lens is set as f, a relation of 11.000 < d / f < 15.000 is satisfied.

[0015] In the wide-angle lens according to the present application, a relation of d / f > 11.000 is satisfied, and thus, it is easy to appropriately correct various aberrations, and it is easy to achieve excellent optical characteristics. On the other hand, a relation of d / f < 15.000 is satisfied, and thus, it is possible to suppress an increase in size of the lens system while avoiding an excessive increase in length of the entire lens system. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a diagram illustrating a wide-angle lens according to Embodiment 1 of the present application.

[0017] Figure 2A is a diagram illustrating field curvature and distortion of the wide-angle lens according to Embodiment 1 of the present application.

[0018] Figure 2B is a diagram showing the field curvature and distortion of the wide-angle lens of Embodiment 1 of the present application.

[0019] Figure 3A is a diagram showing the lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 1 of the present application.

[0020] Figure 3B is a diagram showing the longitudinal chromatic aberration (longitudinal aberration) of the wide-angle lens of Embodiment 1 of the present application.

[0021] Figures 4A to 4L is a diagram showing the lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 1 of the present application.

[0022] Figure 5 is a diagram showing the wide-angle lens of Embodiment 2 of the present application.

[0023] Figure 6A is a diagram showing the field curvature and distortion of the wide-angle lens of Embodiment 2 of the present application.

[0024] Figure 6B is a diagram showing the field curvature and distortion of the wide-angle lens of Embodiment 2 of the present application.

[0025] Figure 7A is a diagram showing the lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 2 of the present application.

[0026] Figure 7B is a diagram showing the longitudinal chromatic aberration (longitudinal aberration) of the wide-angle lens of Embodiment 2 of the present application.

[0027] Figures 8A to 8L is a diagram showing the lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 2 of the present application.

[0028] Figure 9 is a diagram showing the wide-angle lens of Embodiment 3 of the present application.

[0029] Figure 10A is a diagram showing the field curvature and distortion of the wide-angle lens of Embodiment 3 of the present application.

[0030] Figure 10B is a diagram showing the field curvature and distortion of the wide-angle lens of Embodiment 3 of the present application.

[0031] Figure 11A is a diagram showing the lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 3 of the present application.

[0032] Figure 11BFIG. 2 is a graph showing the field curvature and distortion of the wide-angle lens according to Embodiment 1 of the present application.

[0033] Figures 12A to 12L FIG. 3 is a graph showing the lateral aberration of the wide-angle lens according to Embodiment 1 of the present application.

[0034] Figure 13 FIG. 4 is a graph showing the wide-angle lens according to Embodiment 2 of the present application.

[0035] Figure 14A FIG. 5 is a graph showing the field curvature and distortion of the wide-angle lens according to Embodiment 2 of the present application.

[0036] Figure 14B FIG. 6 is a graph showing the field curvature and distortion of the wide-angle lens according to Embodiment 2 of the present application.

[0037] Figure 15A FIG. 7 is a graph showing the lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens according to Embodiment 2 of the present application.

[0038] Figure 15B FIG. 8 is a graph showing the spherical aberration (longitudinal chromatic aberration) of the wide-angle lens according to Embodiment 2 of the present application.

[0039] Figures 16A to 16L FIG. 9 is a graph showing the lateral aberration of the wide-angle lens according to Embodiment 2 of the present application.

[0040] Figure 17 FIG. 10 is a graph showing the wide-angle lens according to Embodiment 3 of the present application.

[0041] Figure 18A FIG. 11 is a graph showing the field curvature and distortion of the wide-angle lens according to Embodiment 3 of the present application.

[0042] Figure 18B FIG. 12 is a graph showing the field curvature and distortion of the wide-angle lens according to Embodiment 3 of the present application.

[0043] Figure 19A FIG. 13 is a graph showing the lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens according to Embodiment 3 of the present application.

[0044] Figure 19B FIG. 14 is a graph showing the spherical aberration (longitudinal chromatic aberration) of the wide-angle lens according to Embodiment 3 of the present application.

[0045] Figures 20A to 20L FIG. 15 is a graph showing the lateral aberration of the wide-angle lens according to Embodiment 3 of the present application.

[0046] Figure 21 FIG. 16 is a graph showing the wide-angle lens according to Embodiment 4 of the present application.

[0047] Figure 22Ais a diagram showing field curvature and distortion of the wide-angle lens of Embodiment 6 of the present application.

[0048] Figure 22B is a diagram showing field curvature and distortion of the wide-angle lens of Embodiment 6 of the present application.

[0049] Figure 23A is a diagram showing lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 6 of the present application.

[0050] Figure 23B is a diagram showing longitudinal chromatic aberration (longitudinal aberration) of the wide-angle lens of Embodiment 6 of the present application.

[0051] Figures 24A to 24L is a diagram showing lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 6 of the present application.

[0052] Figure 25 is a diagram showing the wide-angle lens of Embodiment 7 of the present application.

[0053] Figure 26A is a diagram showing field curvature and distortion of the wide-angle lens of Embodiment 7 of the present application.

[0054] Figure 26B is a diagram showing field curvature and distortion of the wide-angle lens of Embodiment 7 of the present application.

[0055] Figure 27A is a diagram showing lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 7 of the present application.

[0056] Figure 27B is a diagram showing longitudinal chromatic aberration (longitudinal aberration) of the wide-angle lens of Embodiment 7 of the present application.

[0057] Figures 28A to 28L is a diagram showing lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 7 of the present application.

[0058] Figure 29 is a diagram showing the wide-angle lens of Embodiment 8 of the present application.

[0059] Figure 30A is a diagram showing field curvature and distortion of the wide-angle lens of Embodiment 8 of the present application.

[0060] Figure 30B is a diagram showing field curvature and distortion of the wide-angle lens of Embodiment 8 of the present application.

[0061] Figure 31A is a diagram showing lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 8 of the present application.

[0062] Figure 31Bis a diagram showing the spherical aberration (longitudinal aberration) of the wide-angle lens of Embodiment 8 of the present application.

[0063] Figures 32A to 32L is a diagram showing the lateral aberration of the wide-angle lens of Embodiment 8 of the present application.

[0064] (Symbol explanation)

[0065] 1000 Wide-angle lens

[0066] 110 First lens

[0067] 120 Second lens

[0068] 130 Third lens

[0069] 140 Fourth lens

[0070] 150 Fifth lens

[0071] 160 Sixth lens

[0072] 170 Seventh lens

[0073] 180 Stop

[0074] 190 Shutter

[0075] 200 Filter

[0076] 300 Imaging element DETAILED DESCRIPTION

[0077] Hereinafter, each embodiment of the wide-angle lens of the present application will be described with reference to the accompanying drawings. Also, in the following description, in the direction of extension of the optical axis L, L1 is marked on the object side, and L2 is marked on the image side.

[0078] (Embodiment 1)

[0079] Figure 1 is a diagram showing the spherical aberration (longitudinal aberration) of the wide-angle lens of Embodiment 1 of the present application, Figure 2A is a diagram showing the field curvature and distortion of the wide-angle lens of Embodiment 1 of the present application, Figure 2B is a diagram showing the field curvature and distortion of the wide-angle lens of Embodiment 1 of the present application, Figure 3A is a diagram showing the lateral chromatic aberration (lateral color) of the wide-angle lens of Embodiment 1 of the present application, Figure 3B is a diagram showing the spherical aberration (longitudinal aberration) of the wide-angle lens of Embodiment 1 of the present application, Figures 4A to 4L is a diagram showing the lateral aberration of the wide-angle lens of Embodiment 1 of the present application. Here, in Figure 2A , Figure 2B , Figure 3A ,Figure 3B , Figures 4A to 4L In FIG. 2, the correlation curve for red light R (wavelength 656 nm) is labeled R, the correlation curve for green light Rgreenlight G (wavelength 588 nm) is labeled G, the correlation curve for blue light B (wavelength 486 nm) is labeled B, T indicates correlation with the meridional plane, and S indicates correlation with the sagittal plane, and in FIG. 2, the maximum scale of the vertical axis is ± 50.000 μm. Figures 4A to 4L

[0080] As shown in FIG. 1, the wide-angle lens 1000 includes, in order from the object side (L1 side), a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170, wherein the sixth lens 160 and the seventh lens 170 are bonded together by an adhesive to constitute a cemented lens. Figure 1 Here, the first lens 110 is a lens with negative power (referred to simply as a negative lens) in which a convex surface (first surface 1) faces the object side L1 and a concave surface (second surface 2) faces the image side L2. In the present embodiment, the first lens 110 is a glass lens in which the first surface 1 and the second surface 2 are spherical.

[0081] The second lens 120 is a lens with negative power in which a convex surface (third surface 3) faces the object side L1 and a concave surface (fourth surface 4) faces the image side L2. In the present embodiment, the second lens 120 is a plastic lens in which the third surface 3 and the fourth surface 4 are aspherical.

[0082] The third lens 130 is a lens with positive power (referred to simply as a positive lens) in which a concave surface (fifth surface 5) faces the object side L1 and a convex surface (sixth surface 6) faces the image side L2. In the present embodiment, the third lens 130 is a plastic lens in which the fifth surface 5 and the sixth surface 6 are aspherical.

[0083] The fourth lens 140 is a lens with positive power in which a convex surface (seventh surface 7) faces the object side L1 and a convex surface (eighth surface 8) faces the image side L2. In the present embodiment, the fourth lens 140 is a plastic lens in which the seventh surface 7 and the eighth surface 8 are aspherical.

[0084] The fifth lens 150 is a lens with positive power in which a convex surface (tenth surface 10) faces the object side L1 and a convex surface (eleventh surface 11) faces the image side L2. In the present embodiment, the fifth lens 150 is composed of a glass lens.

[0085]

[0086] ​​The sixth lens 160 is a lens having a negative refractive power with a concave surface (twelfth surface 12) facing the object side LI and a concave surface (thirteenth surface 13) facing the image side L2, and constitutes a cemented lens with the seventh lens 170. In the present embodiment, the sixth lens 160 is a plastic lens with the twelfth surface 12 and the thirteenth surface 13 being aspherical surfaces.

[0087] The seventh lens 170 is a lens having a positive refractive power with a convex surface (thirteenth surface 13) facing the object side LI and a convex surface (fourteenth surface 14) facing the image side L2. In the present embodiment, the seventh lens 170 is a plastic lens with the thirteenth surface 13 and the fourteenth surface 14 being aspherical surfaces.

[0088] Further, in the present embodiment, as shown in FIG. 1, a light shield 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and an image pickup element 300 is disposed on the image side of the filter 200. Figure 1

[0089] In the present embodiment, the effective focal length f of the entire lens system is 1.023 mm, the total track d is 13.611 mm, the image space F / # is 2.02, the maximum half field angle is 115 degrees, and the entrance pupil diameter HEP is 0.507 mm.

[0090] The physical properties of each surface of the wide-angle lens 1000 of the present embodiment are shown in Table 1, and the aspherical coefficients of each surface of the wide-angle lens 1000 of the present embodiment are shown in Table 2-1 and Table 2-2.

[0091] (Table 1)

[0092]

[0093] In Table 1 above, the units of the radius of curvature, the thickness, and the effective focal length are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates an aspherical surface, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0094] (Table 2-1)

[0095]

[0096] (Table 2-2)

[0097] Face A8 A10 A12 A14 A16 3 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 4 -3.29328E-03 2.82298E-03 -4.88754E-04 0.00000E+00 0.00000E+00 5 -5.12306E-03 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 6 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 7 4.37857E-03 2.92148E-03 0.00000E+00 0.00000E+00 0.00000E+00 8 -5.94177E-03 1.11565E-02 0.00000E+00 0.00000E+00 0.00000E+00 12 1.79956E-02 -7.87537E-04 -1.30556E-03 0.00000E+00 0.00000E+00 13 1.73181E-01 -4.77496E-02 4.65741E-03 0.00000E+00 0.00000E+00 14 1.34046E-02 -4.35536E-03 5.73510E-04 0.00000E+00 0.00000E+00

[0098] ​In Tables 2-1 and 2-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0099] Further, in Tables 2-1 and 2-2 above, aspherical coefficients A4, A6, A8, A10, A12, A14, and A16 at the time of expressing the aspherical shape of each surface by the following equation (Mathematical Formula 1) are shown. In the following equation, the sag amount (axial direction of the optical axis) is set to Z, the height in the direction perpendicular to the optical axis (ray height) is set to r, the conic coefficient is set to K, and the reciprocal of the curvature radius is set to c.

[0100] [Mathematical Formula 1]

[0101]

[0102] Here, in the wide-angle lens 1000, as shown in FIG. 10, ARS31 represents half the length of the profile curve of the object side lens surface of the third lens 130, and sd31 represents the effective radius of the object side lens surface of the third lens 130. Figure 1

[0103] In the wide-angle lens 1000 of the present embodiment, ARS31 is 1.397 mm, and sd31 is 1.396 mm, and thus the following Condition 1 is satisfied.

[0104] 1.000 < ARS31 / sd31 < 1.0500

[0105] In Condition 1, if ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 will not become a flat surface, and thus various aberrations can be appropriately corrected.

[0106] On the other hand, if ARS31 / sd31 is less than 1.0500, the sag amount of the object side lens surface of the third lens 130 will not be excessively large (deep), and thus ghosting (particularly, point-like ghosting) due to reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0107] Further, in the wide-angle lens 1000 of the present embodiment, ARS22 is 1.997 mm, and sd22 is 1.461 mm, and thus the following Condition 2 is satisfied.

[0108] 1.2000 < ARS22 / sd22 < 1.5000

[0109] ​In the condition 2, if ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can ensure sufficient negative power. Thus, each aberration can be appropriately corrected.

[0110] On the other hand, if ARS22 / sd22 is less than 1.5000, the angle of the peripheral portion of the image side lens surface of the second lens 120 and the tangent can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus, reduction of cost can be achieved.

[0111] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the entire wide-angle lens 1000, f3 is 6.742 mm, and f is 1.023 mm, and thus, the following condition 3 is satisfied:

[0112] 3.000 < f3 / f < 12.500

[0113] In the condition 3, if f3 / f is greater than 3.000, excessively large positive power can be avoided. Thus, each aberration such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical characteristics can be achieved.

[0114] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus, miniaturization of the wide-angle lens can be achieved.

[0115] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the entire optical lens, where f34 is 3.122 mm and f is 1.023 mm, and thus, the following condition 4 is satisfied:

[0116] 2.000 < f34 / f < 5.000

[0117] In the condition 4, if f34 / f is greater than 2.000, excessively large positive power can be avoided. Thus, each aberration such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical characteristics can be achieved.

[0118] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus, miniaturization of the wide-angle lens can be achieved.

[0119] Further, in the wide-angle lens 1000, the object-image distance d is 13.611 mm, and the focal distance f of the entire lens system is 1.023 mm, and thus, the following condition 5 is satisfied:

[0120] 11.000 < d / f < 15.000

[0121] In condition 5, if d / f is 11.000 or less, it is difficult to appropriately correct various aberrations, on the other hand, if d / f is 15.000 or more, the length of the entire lens system becomes too long.

[0122] On the contrary, in the present embodiment, since condition 5 is satisfied, it is easy to appropriately correct various aberrations, it is easy to obtain excellent optical characteristics, and it is possible to suppress the lens system from becoming too large while avoiding the length of the entire lens system from becoming too long.

[0123] As described above, in the present embodiment, by configuring the wide-angle lens 1000 in the above-described manner, as shown in Figures 1 to 4A to Figure 4L indicated, it is possible to appropriately correct various aberrations such as field curvature, lateral chromatic aberration, and coma, and it is possible to reduce the lens radius and the object-image distance, thereby making it possible to achieve miniaturization of the wide-angle lens, and it is possible to suppress ghosting caused by multiple reflection between the lenses.

[0124] (Embodiment 2)

[0125] Figure 5 is a view showing a wide-angle lens of Embodiment 2 of the present application, Figure 6A is a view showing field curvature and distortion of the wide-angle lens of Embodiment 2 of the present application, Figure 6B is a view showing field curvature and distortion of the wide-angle lens of Embodiment 2 of the present application, Figure 7A is a view showing lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 2 of the present application, Figure 7B is a view showing spherical aberration (longitudinal chromatic aberration) of the wide-angle lens of Embodiment 2 of the present application, Figures 8A to 8L is a view showing transverse aberration of the wide-angle lens of Embodiment 2 of the present application. Here, in Figure 6A , Figure 6B , Figure 7A , Figure 7B , Figures 8A to 8L , the relevant curve for red light R (wavelength: 656 nm) is labeled R, the relevant curve for green light R green light G (wavelength: 588 nm) is labeled G, the relevant curve for blue light B (wavelength: 486 nm) is labeled B, T indicates the meridional plane, and S indicates the sagittal plane, and in Figures 8A to 8L , the maximum scale of the vertical axis is ±50.000 μm.

[0126] As shown in Figure 5As shown, the wide-angle lens 1000 includes, in order from the object side (L1 side), a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170, wherein the sixth lens 160 and the seventh lens 170 are bonded together by an adhesive to constitute a bonded lens.

[0127] Here, since the basic structure of the wide-angle lens 1000 in the present embodiment (i.e., whether the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 have positive or negative refractive power, are glass lenses or plastic lenses, whether the object-side surface and the image-side surface are convex or concave, and whether they are spherical or aspherical) is the same as that of the wide-angle lens in Embodiment 1, detailed explanation is not given here.

[0128] Further, as shown, like Embodiment 1, a light-shielding sheet 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and an image pickup element 300 is disposed on the image side of the filter 200. Figure 5

[0129] In the present embodiment, the effective focal length f of the entire lens system is 1.062 mm, the total track d is 13.610 mm, the image space F / # is 2.02, the maximum half field angle is 115 degrees, and the entrance pupil diameter HEP is 0.526 mm.

[0130] The physical properties of each surface of the wide-angle lens 1000 of the present embodiment are shown in Table 3, and the aspherical coefficients of each surface of the wide-angle lens 1000 of the present embodiment are shown in Table 4-1 and Table 4-2.

[0131] (Table 3)

[0132]

[0133] In Table 3 above, the units of the radius of curvature, the thickness, and the focal length are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates that it is aspherical, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0134] (Table 4-1)

[0135]

[0136] (Table 4-2)​

[0137] Face A8 A10 A12 A14 A16 3 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 4 1.18832E-02 -3.21383E-03 7.23623E-04 0.00000E+00 0.00000E+00 5 -7.11892E-03 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 6 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 7 1.48329E-02 -9.20347E-04 0.00000E+00 0.00000E+00 0.00000E+00 8 3.16264E-03 4.17741E-03 0.00000E+00 0.00000E+00 0.00000E+00 12 -7.44565E-04 -1.42901E-03 0.00000E+00 0.00000E+00 0.00000E+00 13 1.80337E-01 -4.80759E-02 4.57265E-03 0.00000E+00 0.00000E+00 14 1.50208E-02 -4.69107E-03 5.90742E-04 0.00000E+00 0.00000E+00

[0138] In Tables 4-1 and 4-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0139] Further, in Tables 4-1 and 4-2 above, the aspheric coefficients A4, A6, A8, A10, A12, A14, A16 are shown when the aspheric shape of each surface is expressed by Mathematical Formula 1 above.

[0140] In the present embodiment, the ARS31, sd31 have the same meanings as in Embodiment 1, and thus the marks are not repeated.

[0141] In the wide-angle lens 1000 of the present embodiment, the ARS31 is 1.354, and the sd31 is 1.353 mm, and thus the following Condition 1 is satisfied:

[0142] 1.000 < ARS31 / sd31 < 1.0500

[0143] In Condition 1, if the ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 will not become a plane, and thus various aberrations can be appropriately corrected.

[0144] On the other hand, if the ARS31 / sd31 is less than 1.0500, the sag of the object side lens surface of the third lens 130 will not be excessively large (deep), and thus ghosting (particularly, point-like ghosting) generated by reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0145] Further, in the wide-angle lens 1000 of the present embodiment, the ARS22 is 1.919 mm, and the sd22 is 1.418 mm, and thus the following Condition 2 is satisfied:

[0146] 1.2000 < ARS22 / sd22 < 1.5000

[0147] In Condition 2, if the ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can ensure a sufficient negative power. Thus, various aberrations can be appropriately corrected.

[0148] On the other hand, if the ARS22 / sd22 is less than 1.5000, the angle formed by the peripheral portion of the image side lens surface of the second lens 120 and the tangent line can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus cost reduction can be achieved.

[0149] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the wide-angle lens 1000 as a whole, f3 is 6.297 mm, and f is 1.062 mm, and thus the following condition 3 is satisfied:

[0150] 3.000 < f3 / f < 12.500

[0151] In the condition 3, if f3 / f is greater than 3.000, the positive refractive power can be prevented from being excessively large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0152] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0153] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the optical lens as a whole, where f34 is 3.380 mm and f is 1.023 mm, and thus the following condition 4 is satisfied:

[0154] 2.000 < f34 / f < 5.000

[0155] In the condition 4, if f34 / f is greater than 2.000, the positive refractive power can be prevented from being excessively large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0156] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0157] Further, in the wide-angle lens 1000, the object-image distance d is 13.610 mm, and the focal distance f of the lens system as a whole is 1.062 mm, and thus the following condition 5 is satisfied:

[0158] 11.000 < d / f < 15.000

[0159] In the condition 5, if d / f is 11.000 or less, various aberrations are not easily appropriately corrected, and on the other hand, if d / f is 15.000 or more, the length of the lens system as a whole becomes excessively long.

[0160] In contrast, in the present embodiment, since the condition 5 is satisfied, various aberrations are easily appropriately corrected, excellent optical performance is easily obtained, and the lens system can be prevented from becoming excessively large while the length of the lens system as a whole is prevented from becoming excessively long.

[0161] As described above, in the present embodiment, by configuring the wide-angle lens 1000 in the above-described manner, as Figures 5 to 8A Figure 8L indicated, various aberrations such as field curvature, chromatic aberration of magnification, and coma aberration can be appropriately corrected, and the lens radius and the object-image distance can be reduced, so that the wide-angle lens can be miniaturized, and ghost images caused by multiple reflections between the lenses can be suppressed.

[0162] (Embodiment 3)

[0163] Figure 9 is a diagram illustrating a wide-angle lens of Embodiment 3 of the present application, Figure 10A is a diagram illustrating field curvature and distortion of the wide-angle lens of Embodiment 3 of the present application, Figure 10B is a diagram illustrating field curvature and distortion of the wide-angle lens of Embodiment 3 of the present application, Figure 11A is a diagram illustrating lateral chromatic aberration (transverse chromatic aberration) of the wide-angle lens of Embodiment 3 of the present application, Figure 11B is a diagram illustrating spherical aberration (longitudinal aberration) of the wide-angle lens of Embodiment 3 of the present application, Figures 12A to 12L is a diagram illustrating transverse aberration of the wide-angle lens of Embodiment 3 of the present application. Here, in Figure 10A Figure 10B Figure 11A Figure 11B Figures 12A to 12L in the above-described manner, the relevant curve for red light R (wavelength: 656 nm) is labeled R, the relevant curve for green light R green light G (wavelength: 588 nm) is labeled G, the relevant curve for blue light B (wavelength: 486 nm) is labeled B, T indicates the tangential direction, and S indicates the sagittal direction, and in Figures 12A to 12L the maximum scale of the vertical axis is ±50.000 μm.

[0164] As Figure 9 indicated, the wide-angle lens 1000 includes, in order from the object side (L1 side), a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170, in which the sixth lens 160 and the seventh lens 170 are bonded together by an adhesive to constitute a cemented lens.

[0165] ​​​​​Here, since the basic structure of the wide-angle lens 1000 in this embodiment (i.e., whether the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 have positive or negative refractive power, are glass lenses or plastic lenses, whether the object-side surface and the image-side surface are convex or concave, and whether they are spherical or aspherical) is the same as that of the wide-angle lens in Embodiment 1, detailed explanation is not given here.

[0166] Further, as Figure 9 shown, like Embodiment 1, a light-shielding sheet 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and a camera element 300 is disposed on the image side of the filter 200.

[0167] In this embodiment, the effective focal length f of the entire lens system is 1.026 mm, the total track d is 13.403 mm, the image space F / # is 2.02, the maximum half field angle is 109 degrees, and the entrance pupil diameter HEP is 0.508 mm.

[0168] The physical properties of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 5, and the aspherical coefficients of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 6-1 and Table 6-2.

[0169] (Table 5)

[0170]

[0171] In Table 5 above, the units of the radius of curvature, the thickness, and the effective focal length are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates aspherical, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0172] (Table 6-1)

[0173]

[0174] (Table 6-2)

[0175] Face A8 A10 A12 A14 A16 3 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 4 -1.08170E-02 3.74135E-03 0.00000E+00 0.00000E+00 0.00000E+00 5 -6.95368E-04 2.73435E-05 0.00000E+00 0.00000E+00 0.00000E+00 6 2.29705E-03 -1.23857E-05 0.00000E+00 0.00000E+00 0.00000E+00 7 8.85677E-03 -7.73714E-05 0.00000E+00 0.00000E+00 0.00000E+00 8 4.43504E-03 9.66329E-04 0.00000E+00 0.00000E+00 0.00000E+00 12 3.37862E-04 9.82658E-03 -3.53648E-03 -1.65685E-04 0.00000E+00 13 1.49413E-01 -7.49877E-02 2.96657E-02 -5.71297E-03 0.00000E+00 14 5.78846E-02 -2.66940E-02 6.28648E-03 -5.86821E-04 0.00000E+00

[0176] In Tables 6-1 and 6-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0177] Further, in Tables 6-1 and 6-2 above, the aspherical coefficients A4, A6, A8, A10, A12, A14, and A16 at the time of expressing the aspherical shape of each surface by the above Mathematical Expression 1 are shown.

[0178] In the present embodiment, the ARS31 and the sd31 have the same meanings as in Embodiment 1, and thus the marks are not repeated.

[0179] In the wide-angle lens 1000 of the present embodiment, the ARS31 is 1.468 mm and the sd31 is 1.463 mm, and thus the following Condition 1 is satisfied:

[0180] 1.000 < ARS31 / sd31 < 1.0500

[0181] In Condition 1, if the ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 does not become a plane, and thus various aberrations can be appropriately corrected.

[0182] On the other hand, if the ARS31 / sd31 is less than 1.0500, the sag of the object side lens surface of the third lens 130 does not become excessively large (excessively deep), and thus ghost (particularly, point-like ghost) generated by reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0183] Further, in the wide-angle lens 1000 of the present embodiment, the ARS22 is 2.013 mm and the sd22 is 1.498 mm, and thus the following Condition 2 is satisfied:

[0184] 1.2000 < ARS22 / sd22 < 1.5000

[0185] In Condition 2, if the ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can ensure a sufficient negative power. Thus, various aberrations can be appropriately corrected.

[0186] On the other hand, if the ARS22 / sd22 is less than 1.5000, the angle formed by the peripheral portion of the image side lens surface of the second lens 120 and the tangent line can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus reduction in cost can be achieved.

[0187] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the entire wide-angle lens 1000, f3 is 7.039 mm, and f is 1.026 mm, and thus the following condition 3 is satisfied:

[0188] 3.000 < f3 / f < 12.500

[0189] In the condition 3, if f3 / f is greater than 3.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0190] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0191] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the entire optical lens, where f34 is 3.456 mm and f is 1.026 mm, and thus the following condition 4 is satisfied:

[0192] 2.000 < f34 / f < 5.000

[0193] In the condition 4, if f34 / f is greater than 2.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0194] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0195] Further, in the wide-angle lens 1000, the object-image distance d is 13.403 mm, and the focal distance f of the entire lens system is 1.026 mm, and thus the following condition 5 is satisfied:

[0196] 11.000 < d / f < 15.000

[0197] In the condition 5, if d / f is 11.000 or less, various aberrations can not be appropriately corrected, and on the other hand, if d / f is 15.000 or more, the entire lens system can become too long.

[0198] In contrast, in the present embodiment, since the condition 5 is satisfied, various aberrations can be appropriately corrected, excellent optical performance can be easily achieved, and the entire lens system can be prevented from becoming too large while the length of the entire lens system is prevented from becoming too long.

[0199] In summary, in this embodiment, by constructing the wide-angle lens 1000 in the manner described above, as follows... Figures 9 to 12A to Figure 12L As shown, it can appropriately correct various aberrations such as field curvature, magnification chromatic aberration, and coma aberration. Furthermore, it can reduce the lens radius and the distance between the object and the image, thereby enabling the miniaturization of wide-angle lenses. Moreover, it can suppress ghosting caused by multiple reflections between lenses.

[0200] (Implementation Method 4)

[0201] Figure 13 This is an explanatory diagram showing the wide-angle lens according to Embodiment 4 of the present invention. Figure 14A This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 4 of the present invention. Figure 14B This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 4 of the present invention. Figure 15A This is an explanatory diagram showing the transverse chromatic aberration (lateral chromatic aberration) of the wide-angle lens according to Embodiment 4 of the present invention. Figure 15B This is an explanatory diagram showing the spherical aberration (longitudinal aberration) of the wide-angle lens according to Embodiment 4 of the present invention. Figures 16A to 16L This is an explanatory diagram illustrating the lateral aberration of the wide-angle lens according to Embodiment 4 of the present invention. Here, in Figure 14A , Figure 14B , Figure 15A , Figure 15B , Figures 16A to 16L In the diagram, the correlation curve for red light R (wavelength 656nm) is labeled R, the correlation curve for green light R and green light G (wavelength 588nm) is labeled G, and the correlation curve for blue light B (wavelength 486nm) is labeled B. T represents correlation with the meridional plane, and S represents correlation with the sagittal plane. Furthermore, in... Figures 16A to 16L In the figure, the maximum scale of the vertical axis is ±50.000 μm.

[0202] like Figure 13 As shown, the wide-angle lens 1000 includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170 arranged sequentially from the object side (L1 side). The sixth lens 160 and the seventh lens 170 are bonded together with an adhesive to form a joint lens.

[0203] Here, since the basic structure of the wide-angle lens 1000 in this embodiment (i.e., whether the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 have positive or negative refractive power, are glass lenses or plastic lenses, whether the object-side surface and the image-side surface are convex or concave, and whether they are spherical or aspherical) is the same as that of the wide-angle lens in Embodiment 1, detailed explanation is not given here.

[0204] Further, as Figure 13 shown, like Embodiment 1, a light-shielding sheet 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and a camera element 300 is disposed on the image side of the filter 200.

[0205] In this embodiment, the effective focal length f of the entire lens system is 1.011 mm, the total track d is 13.404 mm, the image space F / # is 2.03, the maximum half field angle is 109 degrees, and the entrance pupil diameter HEP is 0.498 mm.

[0206] The physical properties of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 7, and the aspherical coefficients of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 8-1 and Table 8-2.

[0207] (Table 7)

[0208]

[0209] In Table 7 above, the units of the radius of curvature, the thickness, and the effective focal length are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates that it is aspherical, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0210] (Table 8-1)

[0211]

[0212] (Table 8-2)

[0213] Face A8 A10 A12 A14 A16 3 -1.15147E-03 1.50789E-04 -7.30801E-06 0.00000E+00 0.00000E+00 4 7.01048E-02 -7.98133E-03 -4.17335E-03 0.00000E+00 0.00000E+00 5 1.21716E-02 -8.91664E-03 0.00000E+00 0.00000E+00 0.00000E+00 6 2.05279E-02 -2.11693E-02 5.41203E-03 0.00000E+00 0.00000E+00 7 6.15517E-03 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 8 8.49340E-03 3.83965E-03 -2.61241E-03 0.00000E+00 0.00000E+00 12 -5.25642E-02 5.03801E-02 -2.60337E-02 5.67639E-03 0.00000E+00 13 1.93193E-02 -2.02628E-02 1.27147E-02 -3.03203E-03 0.00000E+00 14 5.37377E-02 -2.41958E-02 5.72598E-03 -5.29799E-04 0.00000E+00

[0214] In Tables 8-1 and 8-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0215] Further, in Tables 8-1 and 8-2 above, the aspheric coefficients A4, A6, A8, A10, A12, A14, and A16 at the time of expressing the aspheric shape of each surface by the above mathematical expression 1 are shown.

[0216] In the present embodiment, the ARS31 and the sd31 have the same meanings as in Embodiment 1, and thus the marks are not repeated.

[0217] In the wide-angle lens 1000 of the present embodiment, the ARS31 is 1.357 mm and the sd31 is 1.355 mm, and thus the following condition 1 is satisfied:

[0218] 1.000 < ARS31 / sd31 < 1.0500

[0219] In the condition 1, if the ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 does not become a plane, and thus various aberrations can be appropriately corrected.

[0220] On the other hand, if the ARS31 / sd31 is less than 1.0500, the sag of the object side lens surface of the third lens 130 does not become excessively large (excessively deep), and thus ghost (particularly, point-like ghost) generated by reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0221] Further, in the wide-angle lens 1000 of the present embodiment, the ARS22 is 1.881 mm and the sd22 is 1.435 mm, and thus the following condition 2 is satisfied:

[0222] 1.2000 < ARS22 / sd22 < 1.5000

[0223] In the condition 2, if the ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can secure a sufficient negative power. Thus, various aberrations can be appropriately corrected.

[0224] On the other hand, if the ARS22 / sd22 is less than 1.5000, the angle formed by the peripheral portion of the image side lens surface of the second lens 120 and the tangent line can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus reduction in cost can be achieved.

[0225] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the entire wide-angle lens 1000, f3 is 7.736 mm, and f is 1.011 mm, and thus the following condition 3 is satisfied:

[0226] 3.000 < f3 / f < 12.500

[0227] In the condition 3, if f3 / f is greater than 3.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0228] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0229] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the entire optical lens, where f34 is 3.614 mm and f is 1.011 mm, and thus the following condition 4 is satisfied:

[0230] 2.000 < f34 / f < 5.000

[0231] In the condition 4, if f34 / f is greater than 2.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0232] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0233] Further, in the wide-angle lens 1000, the object-image distance d is 13.404 mm, and the focal distance f of the entire lens system is 1.011 mm, and thus the following condition 5 is satisfied:

[0234] 11.000 < d / f < 15.000

[0235] In the condition 5, if d / f is 11.000 or less, various aberrations can not be appropriately corrected, and on the other hand, if d / f is 15.000 or more, the entire lens system can become too long.

[0236] In contrast, in the present embodiment, since the condition 5 is satisfied, various aberrations can be appropriately corrected, excellent optical performance can be easily achieved, and the entire lens system can be prevented from becoming too large while the length of the entire lens system is prevented from becoming too long.

[0237] In summary, in this embodiment, by constructing the wide-angle lens 1000 in the manner described above, as follows... Figures 13 to 16A to Figure 16L As shown, it can appropriately correct various aberrations such as field curvature, magnification chromatic aberration, and coma aberration. Furthermore, it can reduce the lens radius and the distance between the object and the image, thereby enabling the miniaturization of wide-angle lenses. Moreover, it can suppress ghosting caused by multiple reflections between lenses.

[0238] (Implementation Method 5)

[0239] Figure 17 This is an explanatory diagram showing the wide-angle lens according to Embodiment 5 of the present invention. Figure 18A This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 5 of the present invention. Figure 18B This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 5 of the present invention. Figure 19A This is an explanatory diagram showing the transverse chromatic aberration (lateral chromatic aberration) of the wide-angle lens according to Embodiment 5 of the present invention. Figure 19B This is an explanatory diagram showing the spherical aberration (longitudinal aberration) of the wide-angle lens according to Embodiment 5 of the present invention. Figures 20A to 20L This is an explanatory diagram illustrating the lateral aberration of the wide-angle lens according to Embodiment 5 of the present invention. Here, in Figure 18A , Figure 18B , Figure 19A , Figure 19B , Figures 20A to 20L In the diagram, the correlation curve for red light R (wavelength 656nm) is labeled R, the correlation curve for green light R and green light G (wavelength 588nm) is labeled G, and the correlation curve for blue light B (wavelength 486nm) is labeled B. T represents correlation with the meridional plane, and S represents correlation with the sagittal plane. Furthermore, in... Figures 20A to 20L In the figure, the maximum scale of the vertical axis is ±50.000 μm.

[0240] like Figure 17 As shown, the wide-angle lens 1000 includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170 arranged sequentially from the object side (L1 side). The sixth lens 160 and the seventh lens 170 are bonded together with an adhesive to form a joint lens.

[0241] In this embodiment, the basic structure of the wide-angle lens 1000 (i.e., whether the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 have positive or negative refractive power, are glass or plastic lenses, whether the object-side surface and the image-side surface are convex or concave, and whether they are spherical or aspherical) is the same as that of the wide-angle lens in Embodiment 1, and thus will not be described in detail here.

[0242] Further, as Figure 17 shown, like Embodiment 1, a light-shielding sheet 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and a camera element 300 is disposed on the image side of the filter 200.

[0243] In this embodiment, the effective focal length f of the entire lens system is 1.021 mm, the total track d is 13.398 mm, the image space F / # is 2, the maximum half field angle is 108 degrees, and the entrance pupil diameter HEP is 0.511 mm.

[0244] The physical properties of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 9, and the aspherical coefficients of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 10-1 and Table 10-2.

[0245] (Table 9)

[0246]

[0247] In Table 9 above, the units of the radius of curvature, the thickness, and the effective focal length are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates that it is aspherical, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0248] (Table 10-1)

[0249]

[0250] (Table 10-2)

[0251] Face A8 A10 A12 A14 A16 3 -1.12779E-03 1.69605E-04 -9.24708E-06 0.00000E+00 0.00000E+00 4 5.54759E-02 -1.43828E-02 -3.40212E-05 0.00000E+00 0.00000E+00 5 4.27755E-03 -5.97392E-03 0.00000E+00 0.00000E+00 0.00000E+00 6 1.27283E-03 -1.01399E-02 2.46941E-03 0.00000E+00 0.00000E+00 7 -2.19533E-02 8.91100E-03 0.00000E+00 0.00000E+00 0.00000E+00 8 -2.59952E-02 1.31396E-02 0.00000E+00 0.00000E+00 0.00000E+00 12 -5.53989E-03 2.10400E-02 -2.03506E-02 6.17103E-03 0.00000E+00 13 7.91865E-02 -3.44941E-02 3.84031E-03 7.90842E-04 0.00000E+00 14 4.18221E-02 -1.79457E-02 3.88481E-03 -3.05248E-04 0.00000E+00

[0252] In Tables 10-1 and 10-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0253] Further, in Tables 10-1 and 10-2 above, the aspheric coefficients A4, A6, A8, A10, A12, A14, and A16 at the time of expressing the aspheric shape of each surface by the above mathematical expression 1 are shown.

[0254] In the present embodiment, the ARS31 and the sd31 have the same meanings as in Embodiment 1, and thus the marks are not repeated.

[0255] In the wide-angle lens 1000 of the present embodiment, the ARS31 is 1.460 mm and the sd31 is 1.450 mm, and thus the following condition 1 is satisfied:

[0256] 1.000 < ARS31 / sd31 < 1.0500

[0257] In the condition 1, if the ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 does not become a plane, and thus various aberrations can be appropriately corrected.

[0258] On the other hand, if the ARS31 / sd31 is less than 1.0500, the sag of the object side lens surface of the third lens 130 does not become excessively large (excessively deep), and thus ghost (particularly, point-like ghost) generated by reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0259] Further, in the wide-angle lens 1000 of the present embodiment, the ARS22 is 2.010 mm and the sd22 is 1.460 mm, and thus the following condition 2 is satisfied:

[0260] 1.2000 < ARS22 / sd22 < 1.5000

[0261] In the condition 2, if the ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can secure a sufficient negative power. Thus, various aberrations can be appropriately corrected.

[0262] On the other hand, if the ARS22 / sd22 is less than 1.5000, the angle formed by the peripheral portion of the image side lens surface of the second lens 120 and the tangent line can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus cost reduction can be achieved.

[0263] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the wide-angle lens 1000 as a whole, f3 is 7.227 mm, and f is 1.021 mm, and thus the following condition 3 is satisfied:

[0264] 3.000 < f3 / f < 12.500

[0265] In the condition 3, if f3 / f is greater than 3.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0266] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0267] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the optical lens as a whole, where f34 is 3.529 mm and f is 1.021 mm, and thus the following condition 4 is satisfied:

[0268] 2.000 < f34 / f < 5.000

[0269] In the condition 4, if f34 / f is greater than 2.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0270] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0271] Further, in the wide-angle lens 1000, the object-image distance d is 13.398 mm, and the focal distance f of the lens system as a whole is 1.021 mm, and thus the following condition 5 is satisfied:

[0272] 11.000 < d / f < 15.000

[0273] In the condition 5, if d / f is 11.000 or less, various aberrations are not easily appropriately corrected, and on the other hand, if d / f is 15.000 or more, the length of the lens system as a whole becomes too long.

[0274] In contrast, in the present embodiment, since the condition 5 is satisfied, various aberrations are easily appropriately corrected, excellent optical performance is easily obtained, and the lens system can be prevented from becoming too large while the length of the lens system as a whole is prevented from becoming too long.

[0275] In summary, in this embodiment, by constructing the wide-angle lens 1000 in the manner described above, as follows... Figures 17 to 20A to Figure 20L As shown, it can appropriately correct various aberrations such as field curvature, magnification chromatic aberration, and coma aberration. Furthermore, it can reduce the lens radius and the distance between the object and the image, thereby enabling the miniaturization of wide-angle lenses. Moreover, it can suppress ghosting caused by multiple reflections between lenses.

[0276] (Implementation Method 6)

[0277] Figure 21 This is an explanatory diagram showing the wide-angle lens according to Embodiment 6 of the present invention. Figure 22A This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 6 of the present invention. Figure 22B This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 6 of the present invention. Figure 23A This is an explanatory diagram showing the transverse chromatic aberration (lateral chromatic aberration) of the wide-angle lens according to Embodiment 6 of the present invention. Figure 23B This is an explanatory diagram showing the spherical aberration (longitudinal aberration) of the wide-angle lens according to Embodiment 6 of the present invention. Figures 24A to 24L This is an explanatory diagram illustrating the lateral aberration of the wide-angle lens according to Embodiment 6 of the present invention. Here, in Figure 22A , Figure 22B , Figure 23A , Figure 23B , Figures 24A to 24L In the diagram, the correlation curve for red light R (wavelength 656nm) is labeled R, the correlation curve for green light R and green light G (wavelength 588nm) is labeled G, and the correlation curve for blue light B (wavelength 486nm) is labeled B. T represents correlation with the meridional plane, and S represents correlation with the sagittal plane. Furthermore, in... Figures 24A to 24L In the figure, the maximum scale of the vertical axis is ±50.000 μm.

[0278] like Figure 21 As shown, the wide-angle lens 1000 includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170 arranged sequentially from the object side (L1 side). The sixth lens 160 and the seventh lens 170 are bonded together with an adhesive to form a joint lens.

[0279] Here, since the basic structure of the wide-angle lens 1000 in this embodiment (i.e., whether the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 have positive or negative refractive power, are glass lenses or plastic lenses, whether the object-side surface and the image-side surface are convex or concave, and whether they are spherical or aspherical) is the same as that of the wide-angle lens in Embodiment 1, detailed explanation is not given here.

[0280] Further, as Figure 21 shown, like Embodiment 1, a light-shielding sheet 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and a camera element 300 is disposed on the image side of the filter 200.

[0281] In this embodiment, the effective focal length f of the entire lens system is 1.018 mm, the total track d is 13.383 mm, the image space F / # is 2, the maximum half field angle is 108 degrees, and the entrance pupil diameter HEP is 0.509 mm.

[0282] The physical properties of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 11, and the aspherical coefficients of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 12-1 and Table 12-2.

[0283] (Table 11)

[0284]

[0285] In Table 11 above, the units of the radius of curvature, the thickness, and the effective focal length are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates aspherical, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0286] (Table 12-1)

[0287]

[0288] (Table 12-2)

[0289] Face A8 A10 A12 A14 A16 3 -1.14938E-03 1.63223E-04 -7.82147E-06 0.00000E+00 0.00000E+00 4 5.61909E-02 -1.28652E-02 -3.10366E-04 0.00000E+00 0.00000E+00 5 2.71037E-03 -6.63668E-03 0.00000E+00 0.00000E+00 0.00000E+00 6 -3.16016E-03 -9.85165E-03 2.97746E-03 0.00000E+00 0.00000E+00 7 -1.96461E-02 8.38631E-03 0.00000E+00 0.00000E+00 0.00000E+00 8 -1.03312E-02 1.03923E-02 0.00000E+00 0.00000E+00 0.00000E+00 12 -8.59213E-03 1.81642E-02 -1.67818E-02 5.17215E-03 0.00000E+00 13 5.15225E-02 -2.02257E-02 1.88707E-03 3.30690E-04 0.00000E+00 14 4.12895E-02 -1.76625E-02 3.69776E-03 -2.59955E-04 0.00000E+00

[0290] In Tables 12-1 and 12-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0291] Further, in Tables 12-1 and 12-2 above, the aspheric coefficients A4, A6, A8, A10, A12, A14, and A16 at the time of expressing the aspheric shape of each surface by the above Mathematical Formula 1 are shown.

[0292] In the present embodiment, the ARS31 and the sd31 have the same meanings as in Embodiment 1, and thus the marks are not repeated.

[0293] In the wide-angle lens 1000 of the present embodiment, the ARS31 is 1.365 mm and the sd31 is 1.350 mm, and thus the following Condition 1 is satisfied.

[0294] 1.000 < ARS31 / sd31 < 1.0500

[0295] In Condition 1, if the ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 does not become a plane, and thus various aberrations can be appropriately corrected.

[0296] On the other hand, if the ARS31 / sd31 is less than 1.0500, the sag of the object side lens surface of the third lens 130 does not become excessively large (excessively deep), and thus ghost (particularly, point-like ghost) generated by reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0297] Further, in the wide-angle lens 1000 of the present embodiment, the ARS22 is 1.854 mm and the sd22 is 1.350 mm, and thus the following Condition 2 is satisfied.

[0298] 1.2000 < ARS22 / sd22 < 1.5000

[0299] In Condition 2, if the ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can secure a sufficient negative power. Thus, various aberrations can be appropriately corrected.

[0300] On the other hand, if the ARS22 / sd22 is less than 1.5000, the angle formed by the peripheral portion of the image side lens surface of the second lens 120 and the tangent line can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus cost reduction can be achieved.

[0301] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the entire wide-angle lens 1000, f3 is 9.374 mm, and f is 1.018 mm, and thus the following condition 3 is satisfied:

[0302] 3.000 < f3 / f < 12.500

[0303] In the condition 3, if f3 / f is greater than 3.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0304] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0305] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the entire optical lens, where f34 is 3.338 mm and f is 1.018 mm, and thus the following condition 4 is satisfied:

[0306] 2.000 < f34 / f < 5.000

[0307] In the condition 4, if f34 / f is greater than 2.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0308] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0309] Further, in the wide-angle lens 1000, the object-image distance d is 13.383 mm, and the focal distance f of the entire lens system is 1.018 mm, and thus the following condition 5 is satisfied:

[0310] 11.000 < d / f < 15.000

[0311] In the condition 5, if d / f is 11.000 or less, various aberrations can not be appropriately corrected, and on the other hand, if d / f is 15.000 or more, the entire lens system can become too long.

[0312] In contrast, in the present embodiment, since the condition 5 is satisfied, various aberrations can be appropriately corrected, excellent optical performance can be easily obtained, and the entire lens system can be prevented from becoming too large while the length of the entire lens system is prevented from becoming too long.

[0313] In summary, in this embodiment, by constructing the wide-angle lens 1000 in the manner described above, as follows... Figures 21 to 24A to Figure 24L As shown, it can appropriately correct various aberrations such as field curvature, magnification chromatic aberration, and coma aberration. Furthermore, it can reduce the lens radius and the distance between the object and the image, thereby enabling the miniaturization of wide-angle lenses. Moreover, it can suppress ghosting caused by multiple reflections between lenses.

[0314] (Implementation Method 7)

[0315] Figure 25 This is an explanatory diagram showing the wide-angle lens according to Embodiment 7 of the present invention. Figure 26A This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 7 of the present invention. Figure 26B This is an explanatory diagram showing the field curvature and distortion of the wide-angle lens according to Embodiment 7 of the present invention. Figure 27A This is an explanatory diagram showing the transverse chromatic aberration (lateral chromatic aberration) of the wide-angle lens according to Embodiment 7 of the present invention. Figure 27B This is an explanatory diagram showing the spherical aberration (longitudinal aberration) of the wide-angle lens according to Embodiment 7 of the present invention. Figures 28A to 28L This is an explanatory diagram illustrating the lateral aberration of the wide-angle lens according to Embodiment 7 of the present invention. Here, in Figure 26A , Figure 26B , Figure 27A , Figure 27B , Figures 28A to 28L In the diagram, the correlation curve for red light R (wavelength 656nm) is labeled R, the correlation curve for green light R and green light G (wavelength 588nm) is labeled G, and the correlation curve for blue light B (wavelength 486nm) is labeled B. T represents correlation with the meridional plane, and S represents correlation with the sagittal plane. Furthermore, in... Figures 28A to 28L In the figure, the maximum dimension of the vertical axis is ±50.000 μm.

[0316] like Figure 25 As shown, the wide-angle lens 1000 includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170 arranged sequentially from the object side (L1 side). The sixth lens 160 and the seventh lens 170 are bonded together with an adhesive to form a joint lens.

[0317] Here, since the basic structure of the wide-angle lens 1000 in this embodiment (i.e., whether the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 have positive or negative refractive power, are glass lenses or plastic lenses, whether the object-side surface and the image-side surface are convex or concave, and whether they are spherical or aspherical) is the same as that of the wide-angle lens in Embodiment 1, detailed explanation is not given here.

[0318] Further, as Figure 25 shown, like Embodiment 1, a light-shielding sheet 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and a camera element 300 is disposed on the image side of the filter 200.

[0319] In this embodiment, the effective focal length f of the entire lens system is 1.019 mm, the total track d is 13.381 mm, the image space F / # is 2.0163, the maximum half field angle is 108 degrees, and the entrance pupil diameter HEP is 0.505 mm.

[0320] The physical properties of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 13, and the aspherical coefficients of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 14-1 and Table 14-2.

[0321] (Table 13)

[0322]

[0323] In Table 11 above, the units of the radius of curvature, the thickness, and the effective focal length are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates that it is aspherical, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0324] (Table 14-1)

[0325]

[0326] (Table 14-2)

[0327] Face A8 A10 A12 A14 A16 3 -1.15296E-03 1.63212E-04 -7.75247E-06 0.00000E+00 0.00000E+00 4 5.61909E-02 -1.28652E-02 -3.10366E-04 0.00000E+00 0.00000E+00 5 3.12004E-03 -6.74245E-03 0.00000E+00 0.00000E+00 0.00000E+00 6 -3.16016E-03 -9.85165E-03 2.97746E-03 0.00000E+00 0.00000E+00 7 -1.96461E-02 8.38631E-03 0.00000E+00 0.00000E+00 0.00000E+00 8 -1.03312E-02 1.03923E-02 0.00000E+00 0.00000E+00 0.00000E+00 12 -8.59213E-03 1.81642E-02 -1.67818E-02 5.17215E-03 0.00000E+00 13 5.15225E-02 -2.02257E-02 1.88707E-03 3.30690E-04 0.00000E+00 14 4.13120E-02 -1.76585E-02 3.69817E-03 -2.61279E-04 0.00000E+00

[0328] In Tables 14-1 and 14-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0329] Further, in Tables 14-1 and 14-2 above, the aspheric coefficients A4, A6, A8, A10, A12, A14, and A16 at the time of expressing the aspheric shape of each surface by the above mathematical expression 1 are shown.

[0330] In the present embodiment, the ARS31 and sd31 have the same meanings as in Embodiment 1, and thus the marks are not repeated.

[0331] In the wide-angle lens 1000 of the present embodiment, the ARS31 is 1.369 mm and the sd31 is 1.350 mm, and thus the following condition 1 is satisfied:

[0332] 1.000 < ARS31 / sd31 < 1.0500

[0333] In the condition 1, if the ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 does not become a plane, and thus various aberrations can be appropriately corrected.

[0334] On the other hand, if the ARS31 / sd31 is less than 1.0500, the sag of the object side lens surface of the third lens 130 does not become excessively large (excessively deep), and thus ghost (particularly, point-like ghost) generated by reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0335] Further, in the wide-angle lens 1000 of the present embodiment, the ARS22 is 1.854 mm and the sd22 is 1.350 mm, and thus the following condition 2 is satisfied:

[0336] 1.2000 < ARS22 / sd22 < 1.5000

[0337] In the condition 2, if the ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can secure a sufficient negative power. Thus, various aberrations can be appropriately corrected.

[0338] On the other hand, if the ARS22 / sd22 is less than 1.5000, the angle formed by the peripheral portion of the image side lens surface of the second lens 120 and the tangent line can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus reduction in cost can be achieved.

[0339] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the wide-angle lens 1000 as a whole, f3 is 10.047 mm, and f is 1.019 mm, and thus the following condition 3 is satisfied:

[0340] 3.000 < f3 / f < 12.500

[0341] In the condition 3, if f3 / f is greater than 3.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0342] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0343] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the optical lens as a whole, where f34 is 3.394 and f is 1.019 mm, and thus the following condition 4 is satisfied:

[0344] 2.000 < f34 / f < 5.000

[0345] In the condition 4, if f34 / f is greater than 2.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0346] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0347] Further, in the wide-angle lens 1000, the object-image distance d is 13.381 mm, and the focal distance f of the lens system as a whole is 1.019 mm, and thus the following condition 5 is satisfied:

[0348] 11.000 < d / f < 15.000

[0349] In the condition 5, if d / f is 11.000 or less, various aberrations can not be appropriately corrected, and on the other hand, if d / f is 15.000 or more, the length of the lens system as a whole can become too long.

[0350] In contrast, in the present embodiment, since the condition 5 is satisfied, various aberrations can be appropriately corrected, excellent optical performance can be easily obtained, and the lens system can be prevented from becoming too large while the length of the lens system as a whole is prevented from becoming too long.

[0351] As described above, in the present embodiment, the wide-angle lens 1000 is configured in the above-described manner, whereby Figures 25 to 28A As shown in FIG. 1 1, various aberrations such as field curvature, chromatic aberration of magnification, and coma aberration can be appropriately corrected, and the lens radius and the object-image distance can be reduced, so that the wide-angle lens can be downsized, and ghost images caused by multiple reflection between the lenses can be suppressed. Figure 28L As shown in FIG. 1 1, various aberrations such as field curvature, chromatic aberration of magnification, and coma aberration can be appropriately corrected, and the lens radius and the object-image distance can be reduced, so that the wide-angle lens can be downsized, and ghost images caused by multiple reflection between the lenses can be suppressed.

[0352] (Embodiment 8)

[0353] Figure 29 FIG. 1 1 is a diagram showing the wide-angle lens according to Embodiment 8 of the present application, Figure 30A FIG. 1 1 is a diagram showing the wide-angle lens according to Embodiment 8 of the present application, Figure 30B FIG. 1 1 is a diagram showing the wide-angle lens according to Embodiment 8 of the present application, Figure 31A FIG. 1 1 is a diagram showing the wide-angle lens according to Embodiment 8 of the present application, Figure 31B FIG. 1 1 is a diagram showing the wide-angle lens according to Embodiment 8 of the present application, Figures 32A to 32L FIG. 1 1 is a diagram showing the wide-angle lens according to Embodiment 8 of the present application, Figure 30A Figure 30B Figure 31A Figure 31B Figures 32A to 32L In FIG. 1 1, the relevant curve for red light R (wavelength: 656 nm) is labeled R, the relevant curve for green light G (wavelength: 588 nm) is labeled G, the relevant curve for blue light B (wavelength: 486 nm) is labeled B, T indicates the tangential direction, S indicates the sagittal direction, and the maximum scale of the vertical axis is ±50.000 μm. Figures 32A to 32L

[0354] As shown in FIG. 1 1, the wide-angle lens 1000 includes, in order from the object side (L1 side), a first lens 1 10, a second lens 120, a third lens 130, a fourth lens 140, an aperture 180, a fifth lens 150, a sixth lens 160, and a seventh lens 170, wherein the sixth lens 160 and the seventh lens 170 are bonded together by an adhesive to constitute a cemented lens. Figure 29

[0355] ​​​​​​In this embodiment, the basic structure of the wide-angle lens 1000 (i.e., whether the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 have positive or negative refractive power, are glass or plastic lenses, whether the object-side surface and the image-side surface are convex or concave, and whether they are spherical or aspherical) is the same as that of the wide-angle lens in Embodiment 1, and thus will not be described in detail here.

[0356] Further, as Figure 29 shown, like Embodiment 1, a light-shielding sheet 190 is provided between the second lens 120 and the third lens 130, a filter 200 is disposed on the image side of the seventh lens 170, and a camera element 300 is disposed on the image side of the filter 200.

[0357] In this embodiment, the effective focal length f of the entire lens system is 1.030 mm, the total track d is 13.609 mm, the image space F / # is 2, the maximum field of angle is 106 degrees, the entrance pupil diameter HEP is 0.515 mm, and the maximum image height HOI is 2.135 mm.

[0358] The physical properties of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 15, and the aspherical coefficients of each surface of the wide-angle lens 1000 of this embodiment are shown in Table 16-1 and Table 16-2.

[0359] (Table 15)

[0360]

[0361] In Table 15 above, the units of the radius of curvature, the thickness, the focal length, and the effective radius are mm, Nd is the refractive index for a light ray of 587.56 nm, νd is the Abbe number, * indicates that it is aspherical, sd indicates the effective radius of the lens, ARS indicates half the length of the profile curve of the lens surface, and the units of sd and ARS are mm.

[0362] (Table 16-1)

[0363] Face c (1 / radius of curvature) K A4 A6 3 -4.38390E-02 0.00000E+00 1.02948E-02 -1.01140E-03 4 7.88668E-01 -1.13571E+00 5.66499E-02 1.84231E-03 5 2.82343E-01 0.00000E+00 -2.18543E-02 5.16357E-03 6 1.17050E-01 0.00000E+00 -6.48711E-02 -8.41810E-03 7 2.24418E-01 0.00000E+00 3.04785E-02 1.99197E-02 8 -1.03429E-01 0.00000E+00 9.05286E-02 3.48783E-02 12 -1.83670E-01 0.00000E+00 -3.32106E-02 4.95833E-02 13 9.17180E-01 -3.67711E+00 1.58393E-01 -3.03404E-02 14 -5.07238E-01 -6.42125E-01 3.25791E-02 -8.99922E-03

[0364] (Table 16-2)

[0365] Face A8 A10 A12 A14 A16 3 2.82136E-05 8.57444E-16 0.00000E+00 0.00000E+00 0.00000E+00 4 3.99185E-02 -2.56858E-02 9.68214E-03 0.00000E+00 0.00000E+00 5 -3.88312E-04 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 6 3.26148E-03 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 7 -6.50576E-03 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 8 4.33217E-03 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 12 -4.63097E-02 2.53604E-02 -5.68334E-03 0.00000E+00 0.00000E+00 13 -2.77646E-02 2.45247E-02 -5.43979E-03 0.00000E+00 0.00000E+00 14 4.06471E-03 -7.04269E-04 4.21913E-05 0.00000E+00 0.00000E+00

[0366] In Tables 16-1 and 16-2 above, the curvature radius is set to a positive value in the case where the lens surface is a convex surface protruding toward the object side or a concave surface recessed toward the object side, and is set to a negative value in the case where the lens surface is a convex surface protruding toward the image side or a concave surface recessed toward the image side.

[0367] Further, in Tables 16-1 and 16-2 above, the aspheric coefficients A4, A6, A8, A10, A12, A14, and A16 at the time of expressing the aspheric shape of each surface by the above mathematical expression 1 are shown.

[0368] In the present embodiment, the ARS31 and the sd31 have the same meanings as in Embodiment 1, and thus the marks are not repeated.

[0369] In the wide-angle lens 1000 of the present embodiment, the ARS31 is 1.390 mm and the sd31 is 1.366 mm, and thus the following condition 1 is satisfied:

[0370] 1.000 < ARS31 / sd31 < 1.0500

[0371] In the condition 1, if the ARS31 / sd31 is greater than 1.000, the object side lens surface of the third lens 130 does not become a plane, and thus various aberrations can be appropriately corrected.

[0372] On the other hand, if the ARS31 / sd31 is less than 1.0500, the sag of the object side lens surface of the third lens 130 does not become excessively large (excessively deep), and thus ghost (particularly, point-like ghost) generated by reflection between the image side lens surface of the second lens 120 and the L side lens surface of the third lens 130 can be suppressed.

[0373] Further, in the wide-angle lens 1000 of the present embodiment, the ARS22 is 1.995 mm and the sd22 is 1.367 mm, and thus the following condition 2 is satisfied:

[0374] 1.2000 < ARS22 / sd22 < 1.5000

[0375] In the condition 2, if the ARS22 / sd22 is greater than 1.2000, the image side lens surface of the second lens 120 can secure a sufficient negative power. Thus, various aberrations can be appropriately corrected.

[0376] On the other hand, if the ARS22 / sd22 is less than 1.5000, the angle formed by the peripheral portion of the image side lens surface of the second lens 120 and the tangent line can be suppressed from becoming excessively small. Thus, the second lens is easily manufactured, and thus reduction in cost can be achieved.

[0377] Further, in the wide-angle lens 1000 of the present embodiment, f3 represents the focal distance of the third lens 130, f represents the focal distance of the wide-angle lens 1000 as a whole, f3 is 10.255 mm, and f is 1.030 mm, and thus the following condition 3 is satisfied:

[0378] 3.000 < f3 / f < 12.500

[0379] In the condition 3, if f3 / f is greater than 3.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0380] On the other hand, if f3 / f is less than 12.500, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0381] In the wide-angle lens 1000 of the present embodiment, f34 represents the combined focal distance of the third lens 130 and the fourth lens 140, and f represents the focal distance of the optical lens as a whole, where f34 is 3.623, and f is 1.030 mm, and thus the following condition 4 is satisfied:

[0382] 2.000 < f34 / f < 5.000

[0383] In the condition 4, if f34 / f is greater than 2.000, the positive refractive power can be prevented from being too large. Thus, various aberrations such as field curvature, lateral chromatic aberration, and coma can be appropriately corrected, and excellent optical performance can be achieved.

[0384] On the other hand, if f34 / f is less than 5.000, the lens radius and the object-image distance can be reduced, and thus the wide-angle lens can be downsized.

[0385] Further, in the wide-angle lens 1000, the object-image distance d is 13.609 mm, and the focal distance f of the lens system as a whole is 1.030 mm, and thus the following condition 5 is satisfied:

[0386] 11.000 < d / f < 15.000

[0387] In the condition 5, if d / f is 11.000 or less, various aberrations can not be appropriately corrected, and on the other hand, if d / f is 15.000 or more, the length of the lens system as a whole can become too long.

[0388] In contrast, in the present embodiment, since the condition 5 is satisfied, various aberrations can be appropriately corrected, excellent optical performance can be easily obtained, and the lens system can be prevented from becoming too large while the length of the lens system as a whole is prevented from becoming too long.

[0389] As described above, in the present embodiment, by configuring the wide-angle lens 1000 in the above-described manner, it is possible to appropriately correct various aberrations such as field curvature, magnification chromatic aberration, and coma, and to reduce the lens radius and the object-image distance, thereby achieving miniaturization of the wide-angle lens, and it is possible to suppress ghosting caused by multiple reflection between the lenses. Figures 29 to 32A As shown in FIGS. 32A and 32B, various aberrations such as field curvature, magnification chromatic aberration, and coma can be appropriately corrected, and the lens radius and the object-image distance can be reduced, thereby achieving miniaturization of the wide-angle lens, and it is possible to suppress ghosting caused by multiple reflection between the lenses.

[0390] The present application has been described above with reference to the drawings, and it is obvious that the specific implementation of the present application is not limited to the above-described embodiments.

[0391] For example, in the above-described embodiments, the shape of the first surface 1 of the first lens 110, the shape of the third surface 3 of the second lens 120, the shape of the fifth surface 5 of the third lens 130, the shape of the seventh surface 7 of the fourth lens 140, and the shape of the twelfth surface 12 of the sixth lens 160 can be appropriately changed as needed.

[0392] Further, in the above-described embodiments, the first lens 110 and the fifth lens 150 can also be configured by plastic lenses, and the second lens 120, the third lens 130, the fourth lens 140, the sixth lens 160, and the seventh lens 170 can also be configured by glass lenses.

Claims

1. A wide-angle lens characterized by comprising a lens group and an aperture, a plurality of lenses in the lens group being arranged in order from an object side with the aperture interposed therebetween, the plurality of lenses comprising, in order from the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, the first lens being a negative lens, the second lens being a negative lens whose image-side lens surface is concave, the third lens being a positive lens whose object-side lens surface is aspherical, the fourth lens being a positive lens, the fifth lens being a positive lens, the sixth lens being a negative lens, the seventh lens being a positive lens, when half the length of a profile curve of the object-side lens surface of the third lens is set as ARS31 and an effective radius of the object-side lens surface of the third lens is set as sd31, the following relationship is satisfied: 1.0000 < ARS31 / sd31 < 1.0500.

2. The wide-angle lens according to claim 1, characterized in that, the following relationship is satisfied: 1.0000 < ARS31 / sd31 < 1.0200.

3. The wide-angle lens according to claim 1, characterized in that, when half the length of a profile curve of the image-side lens surface of the second lens is set as ARS22 and an effective radius of the image-side lens surface of the second lens is set as sd22, the following relationship is satisfied: 1.2000 < ARS22 / sd22 < 1.5000.

4. The wide-angle lens according to any one of claims 1 to 3, characterized in that, when a focal distance of the third lens is set as f3 and a focal distance of the entire wide-angle lens is set as f, the following relationship is satisfied: 3.000 < f3 / f < 12.

500.

5. The wide-angle lens according to claim 4, characterized in that, the following relationship is satisfied: 5.000 < f3 / f < 10.

000.

6. The wide-angle lens according to any one of claims 1 to 3, characterized in that, when a composite focal distance of the third lens and the fourth lens is set as f34 and a focal distance of the entire wide-angle lens is set as f, the following relationship is satisfied: 2.000 < f34 / f < 5.

000.

7. The wide-angle lens according to claim 6, characterized in that, the following relationship is satisfied: 3.000 < f34 / f < 4.

500.

8. The wide-angle lens according to claim 1, characterized in that, the seven lenses and the aperture are arranged in order from the object side as a first lens, a second lens, a third lens, a fourth lens, the aperture, a fifth lens, a sixth lens, and a seventh lens, the fifth lens is a lens whose object-side lens surface and image-side lens surface are both convex, the sixth lens is a lens whose image-side lens surface is concave, the seventh lens is a lens whose object-side lens surface and image-side lens surface are both convex, the sixth lens and the seventh lens constitute a cemented lens.

9. The wide-angle lens according to claim 8, characterized in that, the first lens and the fifth lens are each a glass lens, ​ The second lens, the third lens, the fourth lens, the sixth lens, and the seventh lens are plastic lenses, respectively.

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