CN-112987237-B - Wide angle lens

Abstract

A wide-angle lens is provided, which is easy to appropriately correct various aberrations such as curvature of field, chromatic aberration of magnification, coma aberration, etc., and which is easy to miniaturize the entire wide-angle lens. The wide-angle lens of the present invention includes, in order from the object side, a first lens that is a negative lens having a concave image-side lens surface, a second lens that is a negative lens having a concave image-side lens surface, a third lens that is a positive lens having a convex image-side lens surface, a fourth lens that is a positive lens having a convex image-side lens surface, a fifth lens that is a positive lens, a sixth lens that is a negative lens, and a seventh lens that is a positive lens, and when the focal distance of the third lens is f3 and the focal distance of the entire wide-angle lens is f, the following relationship is satisfied, 3.000< f3/f <12.500.

Inventors

• Kanzaki Yousuke
• KOMIYAMA TADASHI

Assignees

• 日本电产三协株式会社

Dates

Publication Date

20260508

Application Date

20191213

Claims (6)

1. 1. A wide-angle lens is characterized in that, The number of lenses having optical power is seven, 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 order from the object side, The first lens is a negative lens having a concave image side lens surface, The second lens is a negative lens with a concave image side lens surface, The third lens is a positive lens with a convex image side lens surface, The fourth lens is a positive lens with a convex image side lens surface, The fifth lens is a positive lens and, The sixth lens is a negative lens and, The seventh lens is a positive lens and, When the focal distance of the third lens is f3 and the focal distance of the entire wide-angle lens is f, the following relationship is satisfied: 3.000<f3/f<12.500, The fourth lens is a positive lens with a concave object-side lens surface and a convex image-side lens surface, When the radius of curvature of the object-side lens surface of the fourth lens element is R41, the following relationship is satisfied: -30.000<R41/f<-10.000, when the focal distance of the fourth lens is f4, the following relationship is satisfied: 4.000<f4/f<7.000。
2. 2. The wide angle lens of claim 1 wherein, The following relationship is satisfied: 5.000<f3/f<10.000。
3. 3. the wide angle lens of claim 1 wherein, The following relationship is satisfied: 4.500<f4/f<6.000。
4. 4. The wide-angle lens of any one of claim 1 to 3, The following relationship is satisfied: 13.000<|R41/f|<30.000。
5. 5. the wide-angle lens of any one of claim 1 to 3, The following relationship is satisfied: -25.000<R41/f<-12.000。
6. 6. the wide angle lens of claim 1 wherein, The first lens and the fifth lens are glass lenses respectively, The second lens, the third lens, the fourth lens, the sixth lens, and the seventh lens are plastic lenses, respectively.

Description

Wide angle lens Technical Field The present invention relates to a wide angle lens. Background As a wide-angle lens for an in-vehicle camera, there has been conventionally proposed 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 order from the object side (for example, refer to patent document 1). Patent document 1 Japanese patent laid-open No. 2018-60153 In practice, in order to achieve good optical characteristics, it is desirable to easily correct various aberrations such as curvature of field, chromatic aberration of magnification, and coma aberration of the wide-angle lens, and on the other hand, there is a case where the entire size of a space for mounting the wide-angle lens on a vehicle is limited, and therefore, it is desirable to achieve miniaturization of the entire wide-angle lens. Disclosure of Invention The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a wide-angle lens that can easily and appropriately correct various aberrations such as curvature of field, chromatic aberration of magnification, coma aberration, and the like, and that can easily achieve miniaturization of the entire wide-angle lens. In order to achieve the above object, the present invention provides a wide-angle lens including a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, and a seventh lens arranged in order from an object side, wherein the first lens is a negative lens having a concave image side lens surface, the second lens is a negative lens having a concave image side lens surface, the third lens is a positive lens having a convex image side lens surface, the fourth lens is a positive lens having a convex image side lens surface, the fifth lens is a positive lens, the sixth lens is a negative lens, and the seventh lens is a positive lens, and when a focal distance of the third lens is f3 and a focal distance of the entire wide-angle lens is f, the following relationship is satisfied that 3.000< f3/f <12.500. According to the wide-angle lens of the present invention, the relationship of f3/f >3.000 is satisfied, and therefore, the positive optical power of the third lens is prevented from being excessively strong, and thus, various aberrations such as curvature of field, chromatic aberration of magnification, coma aberration, and the like can be easily corrected appropriately, and excellent optical characteristics can be achieved, and on the other hand, the relationship of f3/f <12.500 is satisfied, and therefore, the lens diameter and the inter-object distance can be reduced, and thus, miniaturization of the entire wide-angle lens can be achieved, and the third lens and the fourth lens are both positive lenses, and therefore, the negative optical power of the first lens and the second lens can be enhanced, and therefore, the diameters of the first lens and the second lens can be reduced, and thus, miniaturization of the entire wide-angle lens can be more easily achieved. Further, in the wide-angle lens of the present invention, it is preferable that the relationship of 5.000< f3/f <10.000 is satisfied. According to the wide-angle lens of the present invention, since the relation of 5.000< f3/f <10.000 is satisfied, it is easier to appropriately correct various aberrations such as curvature of field, chromatic aberration of magnification, coma aberration, etc., so that excellent optical characteristics can be achieved, and the lens diameter and the inter-object distance can be further reduced, thereby achieving miniaturization of the entire wide-angle lens. In the wide-angle lens of the present invention, it is preferable that the focal length of the fourth lens is f4, and the relationship of 4.000< f4/f <7.000 is satisfied. According to the wide-angle lens of the present invention, the relationship of f4/f >4.000 is satisfied, and therefore, excessive positive optical power can be avoided, and thus, various aberrations such as curvature of field, chromatic aberration of magnification, coma aberration, and the like can be easily and appropriately corrected, and excellent optical characteristics can be realized, while on the other hand, the relationship of f4/f <7.000 is satisfied, and therefore, the lens diameter and the inter-object distance can be reduced, and thus, miniaturization of the entire wide-angle lens can be realized. Further, in the wide-angle lens of the present invention, it is preferable that the relationship of 4.500< f4/f <6.000 is satisfied. According to the wide-angle lens of the present invention, since the relation of 4.500< f4/f <6.000 is satisfied, it is easier to appropriately correct various aberrations such as curvature of field, chromatic aberration of magnification, coma aberration, etc., so that excellent optical characteristics can be achieved, and the