JP2019066583A - Imaging lens and camera - Google Patents

Abstract

To provide an imaging lens having bright and high resolution from a center part over a peripheral part, and a camera.SOLUTION: An imaging lens 110 comprises a first lens element 10 with positive refractive power, a second lens element 20 with negative refractive power, a diaphragm 70 with an opening, a third lens element 30 with positive refractive power, a fourth lens element 40 with positive refractive power, and a fifth lens element 50 with negative refractive power, which are sequentially arranged from a subject toward an image pick-up device 120. When a focal distance of the entire lens system is denoted by f, and a distance between a surface of the third lens element 30 facing the subject and a surface thereof facing the image pick-up device 120 is denoted by distance D1, D1/f≥0.294 is satisfied. When a surface of the fifth lens element 50 facing the subject and a surface thereof facing the image pick-up device 120 is denoted by distance D2, D2/f≥0.17 is satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging lens and a camera.

  Development of a driving support system using an on-vehicle camera is in progress. An imaging lens used for an on-vehicle camera is required to have good optical performance. In order to meet this need, Patent Document 1 discloses an imaging lens system having an aspheric lens. In this imaging lens system, distortion is corrected by an aspheric lens, and an image without distortion at the periphery is obtained.

JP, 2016-65954, A

  Vehicle-mounted cameras are required not only to correct distortion but also to have high brightness and resolution at the periphery. For this reason, it is also required that the brightness and resolution of the peripheral part be high also in the imaging lens used for the on-vehicle camera.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an imaging lens and a camera having a bright high resolution from the central portion to the peripheral portion.

In order to achieve the above object, an imaging lens according to a first aspect of the present invention is
Arranged in order from the subject to the imaging device,
A first lens element having a positive refractive power;
A second lens element having a negative refractive power;
An aperture stop having an aperture;
A third lens element having a positive refractive power;
A fourth lens element having a positive refractive power;
And a fifth lens element having a negative refractive power,
Let f be the focal length of the whole lens system,
A distance D1 between the surface of the third lens element facing the subject and the surface facing the image sensor, D1 / f ≧ 0.294,
The distance D2 between the surface of the fifth lens element facing the subject and the surface facing the image sensor, D2 / f ≧ 0.17,
It is characterized by

  By doing this, the radius of curvature of the lens surfaces constituting the third lens element and the fifth lens element can be increased. Thereby, an image having bright and high resolution can be obtained from the center to the periphery.

The first lens element has a first contact surface at the periphery of the surface facing the imaging element.
The second lens element may have a second contact surface in contact with the first contact surface at a peripheral portion of the surface facing the subject.
By doing this, it is possible to prevent the optical axes of the first and second lens elements from being shifted.

The first to fifth lens elements may be made of glass.
By doing this, it is possible to prevent defocus and deterioration of resolution due to temperature change.

Both surfaces of the first to fifth lens elements may be spherical.
By doing so, even when the first to fifth lens elements are made of glass, they can be easily produced.

In order to achieve the above object, a camera according to a second aspect of the present invention is
The imaging lens;
An imaging element on which an object image is formed on an imaging surface by the lens;
Equipped with

  According to the present invention, by satisfying D1 / f ≧ 0.294 and D2 / f ≧ 0.17, the curvature radius of the lens surface constituting the third lens element and the fifth lens element can be increased. This makes it possible to provide an imaging lens and a camera having bright high resolution from the center to the periphery.

It is a sectional view showing a camera concerning an embodiment of the invention. It is a figure which shows the peripheral light intensity ratio of the imaging lens which concerns on Example 1 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 1 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 1 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 1 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 1 of the present invention. It is a figure which shows the peripheral light intensity ratio of the imaging lens which concerns on Example 2 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 2 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 2 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 2 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 2 of the present invention. It is a figure which shows the peripheral light ratio of the imaging lens which concerns on Example 3 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 3 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 3 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 3 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 3 of the present invention. It is a figure which shows the peripheral light ratio of the imaging lens which concerns on Example 4 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 4 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 4 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 4 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 4 of the present invention. It is a figure which shows the peripheral light ratio of the imaging lens which concerns on Example 5 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 5 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 5 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 5 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 5 of the present invention. It is a figure which shows the peripheral light intensity ratio of the imaging lens which concerns on Example 6 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 6 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 6 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 6 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 6 of the present invention. It is a figure which shows peripheral light amount ratio of the imaging lens which concerns on Example 7 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 7 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 7 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 7 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 7 of the present invention. It is a figure which shows the peripheral light intensity ratio of the imaging lens which concerns on Example 8 of this invention. It is a figure which shows MTF of the imaging lens which concerns on Example 8 of this invention. (A) is a figure which shows the curvature of field of the imaging lens which concerns on Example 8 of this invention, (B) shows F-tan (theta) distortion of the imaging lens which concerns on Example 8 of this invention. It is a figure and (C) is a figure showing F-theta distortion of an imaging lens concerning Example 8 of the present invention. FIG. 7 is a cross-sectional view showing a camera according to Comparative Example 1; FIG. 6 is a view showing a peripheral light amount ratio of the imaging lens according to Comparative Example 1; FIG. 6 is a view showing MTF of the imaging lens according to Comparative Example 1; (A) is a figure which shows the curvature of field of the imaging lens which concerns on the comparative example 1, (B) is a figure which shows F-tan (theta) distortion of the imaging lens which concerns on the comparative example 1, (C) FIG. 6 is a diagram showing F-theta distortion of the imaging lens according to Comparative Example 1. FIG. FIG. 7 is a view showing a peripheral light amount ratio of the imaging lens according to Comparative Example 2; FIG. 10 is a view showing MTF of an imaging lens according to Comparative Example 2; (A) is a figure which shows the curvature of field of the imaging lens which concerns on the comparative example 2, (B) is a figure which shows F-tan (theta) distortion of the imaging lens which concerns on the comparative example 2, (C) FIG. 11 is a diagram showing F-theta distortion of the imaging lens according to Comparative Example 2. FIG.

  Hereinafter, an imaging lens according to a mode for carrying out the present invention will be described in detail with reference to the drawings, taking an imaging lens provided in an on-vehicle camera as an example.

  In the camera 100 according to the embodiment of the present invention, as shown in FIG. 1, an object image is formed on an imaging surface by the imaging lens 110 including the first to fifth lens elements 10 to 50 and the imaging lens 110 The imaging device 120, the diaphragm 70, and a housing 130 for accommodating the imaging lens 110, the imaging device 120, and the diaphragm 70 are provided. The camera 100 is used as an on-vehicle camera for capturing an image of the rear of the vehicle. The imaging lens 110 has a focal length f of the entire lens system.

  The imaging element 120 converts an object image formed on the imaging surface by the imaging lens 110 into an electrical signal. The imaging device 120 is not particularly limited as long as it converts an object image into an electrical signal, and is constituted by, for example, a charge-coupled device (CCD) type image sensor, a complementary metal oxide semiconductor (CMOS) type image sensor, or the like. A flat glass filter 60 is disposed on the imaging surface of the imaging element 120. The glass filter 60 is configured of a low pass filter, an infrared cut filter, and the like.

  In the housing 130, the first lens element 10, the second lens element 20, the diaphragm 70, the third lens element 30, the fourth lens element 40, and the fifth lens element 50, in order from the subject toward the image pickup element 120, It is arranged.

  The first lens element 10 is a convex meniscus lens made of glass and having positive refractive power. The surface 11 of the first lens element 10 facing the subject is a convex surface, and the surface 12 facing the image sensor 120 is a concave surface. The surfaces 11 and 12 are shaped as spherical surfaces. The first lens element 10 has a first contact surface 13 at the periphery of the surface 12. For the first lens element 10 in contact with the outside world, glass with high hardness and water resistance is used to enable the camera 100 to be mounted outside the vehicle. It is preferable to use, for the first lens element 10, a glass having a Knoop hardness Hk of 730 or more and a water resistance grade 1. For example, as glass which comprises the 1st lens element 10, it is good to use S-LAH65V (Knoop hardness Hk = 730, water resistance grade 1) made from OHARA. In addition, since the 2nd-5th lens elements 20-50 mentioned later do not contact an external world, you may use glass whose hardness and water resistance are lower than the glass which comprises the 1st lens element 10.

  The second lens element 20 is made of glass and has negative refractive power. The surface 21 facing the subject of the second lens element 20 and the surface 22 facing the image sensor 120 are concave. The surfaces 21 and 22 are shaped as spherical surfaces. The second lens element 20 has a second contact surface 23 in contact with the first contact surface 13 at the periphery of the surface 21.

  The diaphragm 70 is made of non-light transmitting resin having an opening 71 and is disposed between the second lens element 20 and the third lens element 30. The diaphragm 70 is for determining the F-number of the imaging lens 120.

  The third lens element 30 is made of glass and has positive refractive power. The surface 31 of the third lens element 30 facing the subject and the surface 32 of the third lens element 30 facing the image sensor 120 are convex. The surfaces 31 and 32 are formed as spherical surfaces. Assuming that the distance D1 between the surface 32 of the third lens element 30 and the surface 32 on the optical axis L is D1 / f, D1 / f is 0.294 or more, preferably 0.375 or more. Moreover, D1 / f is preferably 0.524 or less, more preferably 0.414 or less. Thereby, the curvature radius of the surface 32 and the surface 32 can be enlarged.

  The fourth lens element 40 is a concave meniscus lens made of glass and having positive refractive power. The surface 41 of the fourth lens element 40 facing the subject is a concave surface, and the surface 42 facing the image sensor 120 is a convex surface. The surfaces 41 and 42 are formed as spherical surfaces. The surface 41 of the fourth lens element 40 is bonded to the surface 32 of the third lens element 30. Thereby, the spherical aberration can be reduced.

  The fifth lens element 50 is a concave meniscus lens made of glass and having negative refractive power. The surface 51 of the fifth lens element 50 facing the subject is a concave surface, and the surface 52 facing the image sensor 120 is a convex surface. The surfaces 51 and 52 are formed as spherical surfaces. Assuming that the distance D2 between the surface 51 of the fifth lens element 50 and the surface 52 is D2, f2 / f is 0.17 or more, preferably 0.311 or more. In addition, preferably, D2 / f is preferably 0.354 or less, more preferably 0.313 or less. Thereby, the curvature radius of the surface 51 and the surface 52 can be enlarged.

  Next, specific numerical examples of the imaging lens 110 having the above configuration will be described below. In Examples 1 to 4, D1 / f is 0.375 or more and 0.414 or less, and D2 / f is 0.311 or more and 0.313 or less. In Examples 5-8, D1 / f is 0.294 or more and 0.524 or less, and D2 / f is an example which is 0.17 or more and 0.354 or less. In the example shown below, when the value of MTF (Modulation Transfer Function) at 83.00 cyc / mm is 0.7 or more at the center and 0.5 or more at the peripheral portion, it is assumed that an excellent resolution is obtained, A resolution of 0.65 or more at the center and 0.45 or more at the periphery is considered to have a good resolution.

Example 1
The imaging lens 110 of Example 1 has a distance D1 of 5.36 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L with the above is 4.08 (mm). D1 / f is 0.4107 and D2 / f is 0.3126.

Object distance: ∞
Focal length f of the entire lens system: f = 13.0506 (mm)
F value: 2.1208
Half angle of view: 12.49 °
Image height: 3.3045 (mm)
Back focus: 2.00948 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 17.8795 (mm)

  Power value of the first lens element 10 = 0.19411, refractive index of the first lens element 10 nd1 = 1.803999, Abbe's number vd1 = 46.58, radius of curvature R11 of the surface 11 = 6.733 (mm), surface 12 curvature radius R12 = 15.982 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 D = 2 = 2.75 (mm)

  Power value of the second lens element 20 = −0.02018, refractive index nd2 of the second lens element 20 = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 of the surface 21 = −41.96 (mm) , Radius of curvature R22 of the surface 22 = 22.242 (mm), diameter = 8.4 (mm), the distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.55 (mm), the surface 21 and the surface Distance D5 on the optical axis L with 22 D = 0.68 (mm)

  The diameter R71 of the opening 71 of the diaphragm 70 = 4.611 (mm), the distance D6 on the optical axis L between the surface 22 and the diaphragm 70 = 0.96 (mm)

  Power value of the third lens element 30 = 0.09911, refractive index of the third lens element 30 nd3 = 1.953747, Abbe's number vd3 = 32.32, radius of curvature R31 of the surface 31 = 9.623 (mm), surface Radius of curvature R32 = −5.249 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the stop 70 and the surface 31 = 0.1 (mm)

  The power value of the fourth lens element 40 is 0.005884, the refractive index of the fourth lens element 40 is nd 4 = 1.92286, the Abbe number vd 4 is 20.88, the curvature radius R 41 of the surface 41 is −5.249 (mm), Radius of curvature R42 of the surface 42 = -21.343 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of the fifth lens element 50 = −0.208559, refractive index nd5 of the fifth lens element 50 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of the surface 51 = −4.059 (mm) , Radius of curvature R52 of the surface 52 = -10.223 (mm), diameter = 9.6 (mm), the distance D9 on the optical axis L between the surface 42 and the surface 51 = 0.99 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 A distance D10 = 1.56448 (mm), a distance D11 = 0.4 (mm) between the surface 61 and the surface 62 on the optical axis L, a distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Example 1 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The solid line T represents the MTF in the tangential plane, and the broken line S represents the MTF in the sagittal plane. The MTF is a spatial frequency characteristic that represents how faithfully the contrast of the subject can be reproduced in order to know the imaging performance of the imaging lens 110. The curvature of field of the imaging lens 110 is shown in FIG. 4A, the F-tan (theta) distortion is shown in FIG. 4B, and the F-theta distortion is shown in FIG. 4C. Field curvature and F-tan (theta) distortion are shown for light at 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively. The solid line in the drawing showing the field curvature represents the field curvature in the tangential plane, and the broken line represents the field curvature in the sagittal plane. In the imaging lens 110 of Example 1, the peripheral light amount ratio is 88% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.7 or more at the center and 0.5 or more at the peripheral portion, and it can be seen that it has excellent resolution. The curvature of field of the imaging lens 110 is distributed between -0.04 and 0.06 mm, which is good. F-tan (theta) distortion is distributed between 0 and 0.5%, and F-theta distortion is distributed between 0 and 2%, which is good.

(Example 2)
The imaging lens 110 of Example 2 has a distance D1 = 4.9 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L with the above is 4.08 (mm). D1 / f is 0.3752 and D2 / f is 0.3124.

Object distance: ∞
Focal length f of the entire lens system f: 13.058 (mm)
F value: 2.1239
Half angle of view: 12.49 °
Image height: 3.3045 (mm)
Back focus: 2.19877 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 17.7488 (mm)

  Power value of the first lens element 10 = 0.1227, refractive index of the first lens element 10 nd1 = 1.803999, Abbe's number vd1 = 46.58, radius of curvature R11 of the surface 11 = 6.586 (mm), surface 12 curvature radius R12 = 15.288 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 D = 2.76 (mm)

  Power value of the second lens element 20 = −0.01968, refractive index nd2 of the second lens element 20 = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 of the surface 21 = −42.509 (mm) , Radius of curvature R22 of the surface 22 = 21.395 (mm), diameter = 8.4 (mm), the distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.55 (mm), the surface 21 and the surface Distance D5 on the optical axis L with 22 D = 0.69 (mm)

  Diameter R71 of the aperture 71 of the aperture 70 = 4.584 (mm), distance D6 on the optical axis L between the surface 22 and the aperture 70 = 0.86 (mm)

  Power value of the third lens element 30 = 0.1024, refractive index of the third lens element 30 nd3 = 1.953747, Abbe's number vd3 = 32.32, radius of curvature R31 of the surface 31 = 9.515 (mm), surface Radius of curvature R32 = −5.531 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the stop 70 and the surface 31 = 0.33 (mm)

  Power value of the fourth lens element 40 = 0.0495, refractive index of the fourth lens element 40 nd 4 = 1.922286, Abbe's number vd 4 = 20.88, radius of curvature of the surface 41 R41 = -5.531 (mm), Radius of curvature R42 of the surface 42 = -20.986 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of the fifth lens element 50 = −0.09115, refractive index nd5 of the fifth lens element 50 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of the surface 51 = −4.153 (mm) , Radius of curvature R52 of the surface 52 = -10.895 (mm), diameter = 9.6 (mm), the distance D9 on the optical axis L between the surface 42 and the surface 51 = 0.98 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 A distance D10 = 1.75377 (mm), a distance D11 = 0.4 (mm) between the surface 61 and the surface 62 on the optical axis L, a distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Example 2 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The curvature of field of the imaging lens 110 is shown in FIG. 7A, the F-tan (theta) distortion is shown in FIG. 7B, and the F-theta distortion is shown in FIG. 7C. Field curvature and F-tan (theta) distortion are shown for light at 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively. In the imaging lens 110 of Example 2, the peripheral light amount ratio is 88% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.7 or more at the center and 0.5 or more at the peripheral portion, and it can be seen that it has excellent resolution. The curvature of field of the imaging lens 110 is distributed between -0.04 and 0.06 mm, which is good. F-tan (theta) distortion is distributed between -0.2 and 0%, and F-theta distortion is distributed between 0 and 2%, which is good.

(Example 3)
The imaging lens 110 of Example 3 has a distance D1 = 5.4 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L with the above is 4.08 (mm). D1 / f is 0.4138 and D2 / f is 0.3126.

Object distance: ∞
Focal length f of the whole lens system: f13.0486 (mm)
F value: 2.1213
Half angle of view: 12.49 °
Image height: 3.3045 (mm)
Back focus: 2.01012 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 17.8901 (mm)

  Power value of first lens element 10 = 0.111916, refractive index of first lens element 10 nd1 = 1.803999, Abbe number vd1 = 46.58, radius of curvature of surface 11 R11 = 6.747 (mm), surface 12 curvature radius R12 = 16.083 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 D = 2.74 (mm)

  Power value of second lens element 20 = −0.02003, refractive index nd2 of second lens element 20 = 1.846663, Abbe number vd2 = 23.78, curvature radius of surface R21 = −42.27 (mm) , Radius of curvature R22 of the surface 22 = 22. 397 (mm), diameter = 8.4 (mm), the distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.44 (mm), the surface 21 and the surface Distance D5 on the optical axis L with 22 D = 0.68 (mm)

  The diameter R71 of the opening 71 of the diaphragm 70 = 4.611 (mm), the distance D6 on the optical axis L between the surface 22 and the diaphragm 70 = 0.96 (mm)

  Power value of the third lens element 30 = 0.0985, refractive index of the third lens element 30 nd3 = 1.953747, Abbe's number vd3 = 32.32, radius of curvature R31 of the surface 31 = 9.683 (mm), surface Radius of curvature of 32 R32 = -5.233 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the stop 70 and the surface 31 = 0.09 (mm)

  Power value of the fourth lens element 40 = 0.5902, refractive index of the fourth lens element 40 nd4 = 1.92286, Abbe's number vd4 = 220.88, radius of curvature R41 of the surface 41 = −5.233 (mm), Radius of curvature R42 of the surface 42 = -21.277 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of the fifth lens element 50 = −0.20833, refractive index nd5 of the fifth lens element 50 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of the surface 51 = −4.064 (mm) , Radius of curvature R52 of the surface 52 = −10.249 (mm), diameter = 9.6 (mm), distance D9 on the optical axis L between the surface 42 and the surface 51 = 0.89 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 A distance D10 = 1.75377 (mm), a distance D11 = 0.4 (mm) between the surface 61 and the surface 62 on the optical axis L, a distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Example 3 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The field curvature of the imaging lens 110 is shown in FIG. 10A, the F-tan (theta) distortion is shown in FIG. 10B, and the F-theta distortion is shown in FIG. 10C. Field curvature and F-tan (theta) distortion are shown for light at 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively. In the imaging lens 110 of Example 3, the peripheral light amount ratio is 88% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.7 or more at the center and 0.5 or more at the peripheral portion, and it can be seen that it has excellent resolution. The curvature of field of the imaging lens 110 is distributed between -0.04 and 0.06 mm, which is good. F-tan (theta) distortion is distributed between 0 and 0.5%, and F-theta distortion is distributed between 0 and 2%, which is good.

(Example 4)
The imaging lens 110 of Example 4 has a distance D1 = 5.36 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L with the above is 4.07 (mm). D1 / f is 0.410479 and D2 / f is 0.31168.

Object distance: ∞
Focal length f of the entire lens system: 13.0579 (mm)
F value: 2.12107
Half angle of view: 12.48 °
Image height: 3.3045 (mm)
Back focus: 2.01965 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 17.98997 (mm)

  Power value of first lens element 10 = 0.11927, refractive index of first lens element 10 nd1 = 1.803999, Abbe number vd1 = 46.58, radius of curvature R11 of surface 11 = 6.741 (mm), surface Curvature radius of 12 R12 = 15.964 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 = 2.75 (mm)

  Power value of the second lens element 20 = −0.02013, refractive index nd2 of the second lens element 20 = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 of the surface 21 = −42.056 (mm) , Radius of curvature R22 of the surface 22 = 21.157 (mm), diameter = 8.4 (mm), the distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.55 (mm), the surface 21 and the surface Distance D5 on the optical axis L with 22 D = 0.68 (mm)

  The diameter R71 of the opening 71 of the diaphragm 70 = 4.604 (mm), the distance D6 on the optical axis L between the surface 22 and the diaphragm 70 = 0.98 (mm)

  Power value of the third lens element 30 = 0.09961, refractive index of the third lens element 30 nd 3 = 1.953747, Abbe's number vd3 = 32.32, radius of curvature R31 of the surface 31 = 9.575 (mm), surface Radius of curvature of 32 R32 = -5.252 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the diaphragm 70 and the surface 31 = 0.01 (mm)

  Power value of the fourth lens element 40 = 0.005881, refractive index of the fourth lens element 40 nd4 = 1.92286, Abbe's number vd4 = 220.88, radius of curvature R41 of the surface 41 = −5.252 (mm), Radius of curvature R42 of the surface 42 = -21.6 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of the fifth lens element 50 = −0.20854, refractive index of the fifth lens element 50 nd5 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of the surface 51 = −4.06 (mm) , Radius of curvature R52 of the surface 52 = −10.192 (mm), diameter = 9.6 (mm), distance D9 on the optical axis L between the surface 42 and the surface 51 = 0.89 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 A distance D10 = 1.57465 (mm), a distance D11 = 0.4 (mm) between the surface 61 and the surface 62 on the optical axis L, a distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Example 4 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The field curvature of the imaging lens 110 is shown in FIG. 13A, the F-tan (theta) distortion is shown in FIG. 13B, and the F-theta distortion is shown in FIG. Field curvature and F-tan (theta) distortion are shown for light at 656 nm, 588 nm, 546 nm, 486 nm, and 436 nm, respectively. In the imaging lens 110 of Example 4, the peripheral light amount ratio is 88% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.7 or more at the center and 0.5 or more at the peripheral portion, and it can be seen that it has excellent resolution. The curvature of field of the imaging lens 110 is distributed between -0.04 and 0.06 mm, which is good. F-tan (theta) distortion is distributed between -0.2 and 0.4%, and F-theta distortion is distributed between 0 and 2%, which is good.

(Example 5)
The imaging lens 110 of Example 5 has a distance D1 = 3.85 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L with the above is 4.08 (mm). D1 / f is 0.2940, and D2 / f is 0.31159.

Object distance: ∞
Focal length f of the entire lens system f: 13.0941 (mm)
F value: 2.1269
Half angle of view: 12.48 °
Image height: 3.3045 (mm)
Back focus: 2.60996 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 17.77 (mm)

  Power value of first lens element 10 = 0.12734, refractive index of first lens element 10 nd1 = 1.803999, Abbe number vd1 = 46.58, radius of curvature R11 of surface 11 = 6.314 (mm), surface Curvature radius of 12 R12 = 13.156 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 D = 2.77 (mm)

  Power value of the second lens element 20 = −0.02186, refractive index nd2 of the second lens element 20 = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 of the surface 21 = −38.735 (mm) , Radius of curvature R22 of the surface 22 = 21.033 (mm), diameter = 8.4 (mm), the distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.49 (mm), the surface 21 and the surface Distance D5 on the optical axis L with 22 D = 1.49 (mm)

  The diameter R71 of the aperture 71 of the aperture 70 = 4.472 (mm), the distance D6 on the optical axis L between the surface 22 and the aperture 70 = 0.36 (mm)

  Power value of third lens element 30 = 0.10608, refractive index of third lens element 30 nd3 = 1.953747, Abbe's number vd3 = 32.32, radius of curvature R31 of surface 31 = 8.991 (mm), surface Radius of curvature R32 = −5.889 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the stop 70 and the surface 31 = 0.67 (mm)

  Power value of the fourth lens element 40 = 0.005245, refractive index nd4 of the fourth lens element 40 nd4 = 1.92286, Abbe number vd4 = 20.88, radius of curvature R41 of the surface 41 = −5.889 (mm), Curvature radius of the surface 42 R42 = −19.287 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of the fifth lens element 50 = −0.19649, refractive index of the fifth lens element 50 nd5 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of the surface 51 = −4.309 (mm) , Radius of curvature R52 of the surface 52 = -12.191 (mm), diameter = 9.6 (mm), distance D9 on the optical axis L between the surface 42 and the surface 51 = 0.85 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 A distance D10 = 2.16496 (mm), a distance D11 on the optical axis L between the surface 61 and the surface 62 = 0.4 (mm), a distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Example 5 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The curvature of field of the imaging lens 110 is shown in FIG. 16 (A), the F-tan (theta) distortion is shown in FIG. 16 (B), and the F-theta distortion is shown in FIG. 16 (C). The curvature of field is shown for light of wavelengths of 656 nm, 588 nm, 546 nm, 486 nm and 436 nm, respectively. In the imaging lens 110 of Example 5, the peripheral light amount ratio is 88% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.65 or more at the center and 0.45 or more at the peripheral portion, and it can be seen that it has a good resolution. The curvature of field of the imaging lens 110 is distributed between -0.04 and 0.07 mm, which is good. F-tan (theta) distortion is distributed between -0.4 and 0%, and F-theta distortion is distributed between 0 and 2%, which is good.

(Example 6)
The imaging lens 110 of Example 6 has a distance D1 of 6.8 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L with the above is 4.08 (mm). D1 / f is 0.5234 and D2 / f is 0.3140.

Object distance: ∞
Focal length f of the entire lens system f: 12.9906 (mm)
F value: 2.1268
Half angle of view: 12.49 °
Image height: 3.3045 (mm)
Back focus: 1.95976 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 18.0598 (mm)

  Power value of first lens element 10 = 0.11656, refractive index of first lens element 10 nd1 = 1.803999, Abbe's number vd1 = 46.58, radius of curvature R11 of surface 11 = 6.898 (mm), surface 12 curvature radius R12 = 18.64 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 D = 2.51 (mm)

  Power value of the second lens element 20 = −0.02055, refractive index of the second lens element 20 nd2 = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 of the surface 21 = −41.21 (mm) , Radius of curvature R22 of the surface 22 = 33.226 (mm), diameter = 8.4 (mm), the distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.48 (mm), the surface 21 and the surface The distance D5 on the optical axis L with 22 D5 = 0.7 (mm)

  The diameter R71 of the opening 71 of the stop 70 = 4.908 (mm), the distance D6 on the optical axis L between the surface 22 and the stop 70 = 0.28 (mm)

  Power value of the third lens element 30 = 0.07285, refractive index of the third lens element 30 nd3 = 1.953747, Abbe number vd3 = 32.32, radius of curvature R31 of the surface 31 = 13.092 (mm), surface Radius of curvature R32 of 32 = -4.754 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the stop 70 and the surface 31 = 0.04 (mm)

  Power value of the fourth lens element 40 = 0.006497, refractive index of the fourth lens element 40 nd4 = 1.92286, Abbe's number vd4 = 20.88, radius of curvature R41 of the surface 41 = −4.754 (mm), Curvature radius of the surface 42 R42 = −14.869 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of the fifth lens element 50 = −0.20555, refractive index nd5 of the fifth lens element 50 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of the surface 51 = −4.119 (mm) , Radius of curvature R52 of the surface 52 = -12.378 (mm), diameter = 9.6 (mm), the distance D9 on the optical axis L between the surface 42 and the surface 51 = 0.81 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 A distance D10 = 1.51476 (mm), a distance D11 = 0.4 (mm) between the surface 61 and the surface 62 on the optical axis L, a distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Example 6 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The curvature of field of the imaging lens 110 is shown in FIG. 19A, the F-tan (theta) distortion is shown in FIG. 19B, and the F-theta distortion is shown in FIG. 19C. The curvature of field is shown for light of wavelengths of 656 nm, 588 nm, 546 nm, 486 nm and 436 nm, respectively. In the imaging lens 110 of Example 6, the peripheral light amount ratio is 88% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.65 or more at the center and 0.5 or more at the periphery, and it can be seen that it has a good resolution. The curvature of field of the imaging lens 110 is distributed between -0.4 and 0.06 mm, which is good. The F-tan (theta) distortion is distributed between 0 and 0.7%, and the F-theta distortion is distributed between 0 and 3%, which is good.

(Example 7)
The imaging lens 110 of Example 7 has a distance D1 = 5.36 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L between them and D2 = 2.3 (mm). D1 / f is 0.4098 and D2 / f is 0.1758.

Object distance: ∞
Focal length f of the entire lens system f: 13.0786 (mm)
F value: 2.1144
Half angle of view: 12.49 °
Image height: 3.3045 (mm)
Back focus: 3.51027 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 17.5921 (mm)

  Power value of first lens element 10 = 0.21234, refractive index of first lens element 10 nd1 = 1.803999, Abbe number vd1 = 46.58, radius of curvature R11 of surface 11 = 6.515 (mm), surface Curvature radius of 12 R12 = 14.843 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 D = 2.76 (mm)

  Power value of the second lens element 20 = −0.01902, refractive index of the second lens element 20 nd2 = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 of the surface 21 = −44.515 (mm) , Radius of curvature R22 of the surface 22 = 13.254 (mm), diameter = 8.4 (mm), distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.53 (mm), the surface 21 and the surface Distance D5 on the optical axis L with 22 D5 = 0.56 (mm)

  The diameter R71 of the aperture 71 of the aperture 70 = 4.699 (mm), the distance D6 on the optical axis L between the surface 22 and the aperture 70 = 0.97 (mm)

  Power value of the third lens element 30 = 0.10951, refractive index of the third lens element 30 nd3 = 1.953747, Abbe's number vd3 = 32.32, radius of curvature R31 of the surface 31 = 8.709 (mm), surface Radius of curvature R32 = −6.49 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the stop 70 and the surface 31 = 0.1 (mm)

  Power value of the fourth lens element 40 = 0.004759, refractive index of the fourth lens element 40 nd4 = 1.92286, Abbe number vd4 = 220.88, radius of curvature R41 of the surface 41 = −6.49 (mm), Radius of curvature R42 of the surface 42 = -22.521 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of the fifth lens element 50 = −0.21397, refractive index nd5 of the fifth lens element 50 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of the surface 51 = −3.957 (mm) , Radius of curvature R52 of the surface 52 = -7.887 (mm), diameter = 9.6 (mm), distance D9 on the optical axis L between the surface 42 and the surface 51 = 1 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 Distance D10 = 3.06707 (mm), distance D11 on the optical axis L between the surface 61 and the surface 62 = 0.4 (mm), distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Example 7 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The curvature of field of the imaging lens 110 is shown in FIG. 22 (A), the F-tan (theta) distortion is shown in FIG. 22 (B), and the F-theta distortion is shown in FIG. 22 (C). The curvature of field is shown for light of wavelengths of 656 nm, 588 nm, 546 nm, 486 nm and 436 nm, respectively. In the imaging lens 110 of Example 7, the peripheral light amount ratio is 87% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.65 or more at the center and 0.45 or more at the peripheral portion, and it can be seen that it has a good resolution. The curvature of field of the imaging lens 110 is distributed between -0.3 and 0.07 mm, which is good. F-tan (theta) distortion is distributed between -0.2 and 0%, and F-theta distortion is distributed between 0 and 2%, which is good.

(Example 8)
The imaging lens 110 of Example 8 has a distance D1 = 5.36 (mm) between the surface 31 of the third lens element 30 and the surface 32 on the optical axis L, and the surfaces 51 and 52 of the fifth lens element 50. And the distance D2 on the optical axis L between them and 4.6 (mm). D1 / f is 0.4116 and D2 / f is 0.3532.

Object distance: ∞
Focal length f of the entire lens system: f13.0218 (mm)
F value: 2.1357
Half angle of view: 12.49 °
Image height: 3.3045 (mm)
Back focus: 1.99655 (mm)
Distance TL on the optical axis L from the surface 11 of the first lens element 10 to the imaging surface of the imaging element 120: 17.7665 (mm)

  Power value of first lens element 10 = 0.12339, refractive index of first lens element 10 nd1 = 1.803999, Abbe's number vd1 = 46.58, radius of curvature R11 of surface 11 = 6.516 (mm), surface 12 curvature radius R12 = 15.43 (mm), diameter = 9.4 (mm), distance D3 on the optical axis L between the surface 11 and the surface 12 = 2.69 (mm)

  Power value of the second lens element 20 = −0.02513, refractive index nd2 of the second lens element 20 = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 of the surface 21 = −33.686 (mm) , Radius of curvature R22 = 37.752 (mm), diameter = 8.4 (mm), distance D4 on the optical axis L between the surface 12 and the surface 21 = 0.54 (mm), the surface 21 and the surface Distance D5 on the optical axis L with 22 D5 = 0.76 (mm)

  Diameter R71 of the aperture 71 of the diaphragm 70 = 4.643 (mm), distance D6 on the optical axis L between the surface 22 and the diaphragm 70 = 0.44 (mm)

  Power value of the third lens element 30 = 0.07921, refractive index of the third lens element 30 nd3 = 1.953747, Abbe's number vd3 = 32.32, radius of curvature R31 of the surface 31 = 12.041 (mm), surface Radius of curvature of 32 R32 = -4.882 (mm), diameter = 5.6 (mm), distance D7 on the optical axis L between the stop 70 and the surface 31 = 0.09 (mm)

  Power value of the fourth lens element 40 = 0.006327, refractive index of the fourth lens element 40 nd4 = 1.92286, Abbe's number vd4 = 220.88, radius of curvature R41 of the surface 41 = −4.882 (mm), Radius of curvature R42 of the surface 42 = -14.428 (mm), diameter = 8.0 (mm), distance D8 on the optical axis L between the surface 41 and the surface 42 = 0.5 (mm)

  Power value of fifth lens element 50 = −0.20635, refractive index of fifth lens element 50 nd5 = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 of surface 51 = −4.103 (mm) , Radius of curvature R52 of the surface 52 = -12.537 (mm), diameter = 9.6 (mm), the distance D9 on the optical axis L between the surface 42 and the surface 51 = 0.99 (mm)

  Refractive index nd 6 of the glass filter 60 = 1.516798, Abbe number vd 6 = 64.2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, the optical axis L between the surface 52 and the surface 61 A distance D10 = 1.55155 (mm), a distance D11 on the optical axis L between the surface 61 and the surface 62 = 0.4 (mm), a distance on the optical axis L between the surface 62 and the imaging surface of the imaging device 120 0.045 (mm)

  The peripheral light amount ratio of the imaging lens 110 of Example 8 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The curvature of field of the imaging lens 110 is shown in FIG. 25 (A), F-tan (theta) distortion is shown in FIG. 25 (B), and F-theta distortion is shown in FIG. 25 (C). The curvature of field is shown for light of wavelengths of 656 nm, 588 nm, 546 nm, 486 nm and 436 nm, respectively. In the imaging lens 110 of Example 8, the peripheral light amount ratio is 87% in the peripheral portion, and it can be seen that the peripheral portion is bright. The value of MTF is 0.7 or more at the center and 0.45 or more at the periphery, and it can be seen that it has a good resolution. The curvature of field of the imaging lens 110 is distributed between -0.4 and 0.6 mm, which is good. The F-tan (theta) distortion is distributed between 0 and 0.4%, and the F-theta distortion is distributed between 0 and 2.5%, which is good.

  In Examples 1 to 4, D1 / f is 0.375 or more and 0.414 or less, and D2 / f is 0.311 or more and 0.313 or less, so that the MTF value is 0.7 or more at the center. , 0.5 or more at the periphery. In Examples 5 to 8, D1 / f is 0.294 or more and 0.524 or less, and D2 / f is 0.17 or more and 0.354 or less, so that the MTF value is 0.65 or more at the center. , Is 0.45 or more in the peripheral part. When D1 / f and D2 / f satisfy the above values, it is understood that the resolution of the central portion and the peripheral portion is excellent or excellent. It is considered that this is because the radius of curvature of the surfaces 32 and 32 and the surfaces 51 and 52 can be increased when D1 / f and D2 / f satisfy the above values. In Examples 1 to 8, it is understood that the peripheral light amount ratio is 87% or more in the peripheral portion, and the peripheral portion is bright. The results of field curvature, F-tan (theta) distortion and F-theta distortion are also good. Further, since the first to fifth lens elements 10 to 50 are made of glass, the shift of the focus due to the temperature change is small as compared with the case of using the lens made of resin. The surfaces constituting the first to fifth lens elements 10 to 50 are formed as spherical surfaces and can be easily created. The first lens element 10 in contact with the outside is made of glass having high hardness and water resistance. Therefore, even if the camera 100 is attached to the outside of the vehicle, the lens is not easily damaged and deterioration of the image quality can be prevented.

  Next, Comparative Example 1 in which D1 / f is less than 0.294 and Comparative Example 2 in which D2 / f is less than 0.17 will be described. The imaging lens 110 'according to Comparative Examples 1 and 2 includes first to fifth lens elements 10' to 50 ', as shown in FIG. Specific numerical values of the imaging lens 110 'are shown below.

(Comparative example 1)
The imaging lens 110 ′ of Comparative Example 1 has a distance D1 ′ = 3.8 (mm) on the optical axis L between the surface 31 ′ of the third lens element 30 ′ and the surface 32 ′, and the fifth lens element 50 ′. The distance D2 '= 4.08 (mm) on the optical axis L between the surface 51' and the surface 52 '. D1 ′ / f ′ is 0.2898, and D2 ′ / f ′ is 0.3112.

Object distance: ∞
Focal length f 'of the entire lens system f: 13.10 (mm)
F value: 2.1291
Half angle of view: 12.48 °
Image height: 3.3045 (mm)
Back focus: 2.67128 (mm)
Distance TL ′ on the optical axis L from the surface 11 ′ of the first lens element 10 ′ to the imaging surface of the imaging element 120: 17.79 (mm)

  Power value of the first lens element 10 ′ = 0.12768, refractive index nd1 = 1.803999 of the first lens element 10 ′, Abbe number vd1 = 46.58, radius of curvature R11 ′ of the surface 11 ′ = 6.297 mm, the radius of curvature R12 ′ of the surface 12 ′ = 12.95 (mm), the diameter = 9.4 (mm), the distance D3 ′ = 2.77 on the optical axis L between the surfaces 11 ′ and 12 ′ mm)

  Power value of the second lens element 20 ′ = − 0.02216, refractive index nd2 of the second lens element 20 ′ = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 ′ of the surface 21 ′ = − 38. 207 (mm), radius of curvature R22 'of surface 22' = 21.096 (mm), diameter = 8.4 (mm), distance D4 'on optical axis L between surface 12' and surface 21 '= 0 6 (mm), the distance D5 '= 1.51 (mm) on the optical axis L between the surface 21' and the surface 22 '

  Diameter R71 of the aperture 71 of the aperture 70 = 4.471 (mm), distance D6 'on the optical axis L between the surface 22' and the aperture 70 = 0.36 (mm)

  Power value of third lens element 30 ′ = 0.10679, refractive index of third lens element 30 ′ nd3 = 1.953747, Abbe number vd3 = 32.32, radius of curvature R31 ′ of surface 31 ′ = 8.931 mm), radius of curvature R32 'of the surface 32' =-5.902 (mm), diameter = 5.6 (mm), distance D7 '= 0.66 (the optical axis L between the diaphragm 70 and the surface 31') mm)

  Power value of the fourth lens element 40 ′ = 0.0052334, refractive index of the fourth lens element 40 ′ nd4 = 1.92286, Abbe number vd4 = 20.88, radius of curvature R41 ′ of the surface 41 ′ = − 5.5. (Mm), radius of curvature R42 'of the surface 42' = -19.167 (mm), diameter = 8.0 (mm), distance D8 'of the surfaces 41' and 42 'on the optical axis L = 0 5 (mm)

  Power value of fifth lens element 50 ′ = − 0.19599, refractive index nd5 of fifth lens element 50 ′ = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 ′ of surface 51 ′ = − 4. 32 (mm), radius of curvature R52 'of the surface 52' = -12.263 (mm), diameter = 9.6 (mm), distance D9 '= 0 on the optical axis L between the surface 42' and the surface 51 ' .84 (mm)

  Refractive index nd 6 of glass filter 60 = 1.516798, Abbe number vd 6 = 64. 2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, on the optical axis L of the surface 52 ′ and the surface 61 Distance D10 ′ = 2.2628 (mm), distance D11 on the optical axis L between the surface 61 and the surface 62 = 0.4 (mm), optical axis L between the surface 62 and the imaging surface of the imaging device 120 Distance = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 'of Comparative Example 1 is shown in FIG. The MTF of the imaging lens 110 'at 83.00 cyc / mm is shown in FIG. The curvature of field of the imaging lens 110 'is shown in FIG. 29A, the F-tan (theta) distortion is shown in FIG. 29B, and the F-theta distortion is shown in FIG. The curvature of field is shown for light of wavelengths of 656 nm, 588 nm, 546 nm, 486 nm and 436 nm, respectively. In the imaging lens 110 ′ of Comparative Example 1, the peripheral light amount ratio is 88% in the peripheral portion. The value of MTF is 0.7 or more at the center and less than 0.45 at the periphery, which indicates poor resolution. The curvature of field of the imaging lens 110 'is distributed between -0.4 and 0.7 mm. F-tan (theta) distortion is distributed between -0.5 and 0%, and F-theta distortion is distributed between 0 and 4%.

(Comparative example 2)
The imaging lens 110 ′ of Comparative Example 2 has a distance D1 ′ = 5.36 (mm) on the optical axis L between the surface 31 ′ of the third lens element 30 ′ and the surface 32 ′, and the fifth lens element 50 ′. The distance D2 '= 2.2 (mm) on the optical axis L between the surface 51' and the surface 52 '. D1 '/ f' is 0.4099 and D2 '/ f' is 0.1682.

Object distance: ∞
Focal length f 'of the whole lens system: 13.0743 (mm)
F value: 2.1133
Half angle of view: 12.49 °
Image height: 3.3045 (mm)
Back focus: 3.59097 (mm)
Distance TL 'on the optical axis L from the surface 11' of the first lens element 10 'to the imaging surface of the imaging element 120: 17.51 (mm)

  Power value of the first lens element 10 ′ = 0.12373, refractive index nd1 = 1.803999 of the first lens element 10 ′, Abbe number vd1 = 46.58, radius of curvature R11 ′ of the surface 11 ′ = 6.498 ( mm, the radius of curvature R12 ′ of the surface 12 ′ = 14.749 (mm), the diameter = 9.4 (mm), the distance D3 ′ = 2.76 (on the optical axis L between the surfaces 11 ′ and 12 ′) mm)

  Power value of second lens element 20 ′ = − 0.01914, refractive index nd2 of second lens element 20 ′ = 1.846663, Abbe number vd2 = 23.78, radius of curvature R21 ′ of surface 21 ′ = − 44. 243 (mm), radius of curvature R22 'of surface 22' = 12.943 (mm), diameter = 8.4 (mm), distance D4 'on optical axis L between surface 12' and surface 21 ' 53 (mm), the distance D5 '= 0.55 (mm) on the optical axis L between the surface 21' and the surface 22 '

  The diameter R71 of the aperture 71 of the aperture 70 = 4.704 (mm), the distance D6 '= 0.97 (mm) on the optical axis L between the surface 22' and the aperture 70

  Power value of third lens element 30 ′ = 0.11009, refractive index of third lens element 30 ′ nd3 = 1.953747, Abbe number vd3 = 32.32, radius of curvature R31 ′ of surface 31 ′ = 8.663 mm), radius of curvature R32 'of the surface 32' = -6.585 (mm), diameter = 5.6 (mm), distance D7 'on the optical axis L between the stop 70 and the surface 31' = 0.09 ( mm)

  Power value of the fourth lens element 40 ′ = 0.004691, refractive index of the fourth lens element 40 ′ nd4 = 1.92286, Abbe number vd4 = 20.88, radius of curvature R41 ′ of the surface 41 ′ = − 6.585 (Mm), radius of curvature R42 'of the surface 42' = -22.547 (mm), diameter = 8.0 (mm), distance D8 'on the optical axis L between the surface 41' and the surface 42 '= 0 5 (mm)

  Power value of the fifth lens element 50 ′ = − 0.21435, refractive index nd5 of the fifth lens element 50 ′ = 1.846663, Abbe number vd5 = 23.78, radius of curvature R51 ′ of the surface 51 ′ = − 3. 95 (mm), radius of curvature R52 'of the surface 52' = -7.76 (mm), diameter = 9.6 (mm), distance D9 'on the optical axis L between the surface 42' and the surface 51 '= 1 .01 (mm)

  Refractive index nd 6 of glass filter 60 = 1.516798, Abbe number vd 6 = 64. 2, curvature radius R 61 of the surface 61 = 、, curvature radius R 62 of the surface 62 = 、, on the optical axis L of the surface 52 ′ and the surface 61 Distance D10 ′ = 3.14597 (mm), distance D11 on the optical axis L between the surface 61 and the surface 62 = 0.4 (mm), optical axis L between the surface 62 and the imaging surface of the imaging device 120 Distance = 0.045 (mm)

  The peripheral light amount ratio in the imaging lens 110 of Comparative Example 2 is shown in FIG. The MTF of the imaging lens 110 at 83.00 cyc / mm is shown in FIG. The field curvature of the imaging lens 110 is shown in FIG. 32 (A), the F-tan (theta) distortion is shown in FIG. 32 (B), and the F-theta distortion is shown in FIG. 32 (C). The curvature of field is shown for light of wavelengths of 656 nm, 588 nm, 546 nm, 486 nm and 436 nm, respectively. In the imaging lens 110 of Comparative Example 2, the peripheral light amount ratio is 87% in the peripheral portion. The value of MTF is less than 0.7 at the center and less than 0.45 at the periphery, which indicates poor resolution. The curvature of field of the imaging lens 110 is distributed between -0.3 and 0.8 mm. The F-tan (theta) distortion is distributed between -0.8 and 0.1%, and the F-theta distortion is distributed between 0 and 2%.

  In Comparative Example 1, D1 / f is less than 0.294. In Comparative Example 2, D2 / f is less than 0.17. Therefore, the MTF values of Comparative Examples 1 and 2 are less than 0.45 at the peripheral portion, and the resolution is poor. Therefore, it is understood that the resolution of the peripheral portion is inferior when D1 / f is less than 0.294 or D2 / f is less than 0.17. In Comparative Example 1, the F-theta distortion is distributed between 0 and 4%, which is larger than Examples 1 to 8 and the distortion is large. In Comparative Example 2, F-tan (theta) distortion is distributed between -0.8 and 0.1%, and it can be seen that the value is larger than in Examples 1 to 8 and distortion is large.

(Modification)
In the above embodiment, an example in which the first to fifth lens elements 10 to 50 are spherical lenses made of glass has been described. Materials forming the first to fifth lens elements 10 to 50 may be materials other than glass, such as resin. The surfaces of the lenses used in the first to fifth lens elements 10 to 50 included in the imaging lens 110 may be formed as a spherical surface, a flat surface, or an aspheric surface. When the lens surface is spherical or flat, it is preferable because processing and assembly adjustment of the lens can be facilitated, and deterioration of optical performance due to processing and assembly adjustment errors can be prevented. When the lens surface is aspheric, any of aspheric aspheric surfaces by grinding, a molded aspheric surface with glass or resin formed into an aspheric shape, and a composite aspheric surface with a resin formed into an aspheric shape on the surface of glass It may be an aspheric surface. Also, if necessary, the surface of the lens may be a diffractive surface, or the lens may be a refractive index distribution lens or the like. In addition, in the entire lens system, various processing can be performed on the surface exposed to the outside at the time of use or the like as needed. As an example of this processing, hydrophilization of the surface portion with a photocatalyst or the like for prevention of fogging of the lens main body and formation of water droplets can be mentioned. Each of the first to fifth lens elements 10 to 50 may be formed of a single lens, or a plurality of lenses may be combined to form a single lens element.

  In the above embodiment, an example in which the third lens element 30 and the fourth lens element 40 included in the imaging lens 110 are cemented lenses has been described. The third lens element 30 and the fourth lens element 40 may be spaced apart.

  In the above-described embodiment, an example in which the imaging lens 110 has the diaphragm 70 has been described. The imaging lens 110 may have an auxiliary stop in addition to the stop 70. Thereby, the aberration can be reduced.

  In the above-mentioned embodiment, the camera 100 demonstrated the example used as a vehicle-mounted camera. The camera 100 is not limited to an object used as a vehicle-mounted camera, and may be used as a consumer camera such as a digital camera, a surveillance camera, a robot camera mounted on a robot, or the like.

  The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope of the present invention. The embodiments described above are for explaining the present invention, and do not limit the scope of the present invention.

  The present invention can be suitably used as an on-vehicle camera.

10, 10 'First lens element 11, 11', 12, 12 'surface 20, 20' second lens element 21, 21 ', 22, 22' surface 30, 30 'third lens element 31, 31', 32 , 32 'surface 40, 40' fourth lens element 41, 41 ', 42, 42' surface 50, 50 'fifth lens element 51, 51', 52, 52 'surface 60, 60' glass filter 70 diaphragm 71 aperture Section 100 Camera 110, 110 'Imaging lens 120 Imaging element 130 Housing f, f' Focal length

Claims (5)

Arranged in order from the subject to the imaging device,
A first lens element having a positive refractive power;
A second lens element having a negative refractive power;
An aperture stop having an aperture;
A third lens element having a positive refractive power;
A fourth lens element having a positive refractive power;
And a fifth lens element having a negative refractive power,
Let f be the focal length of the whole lens system,
A distance D1 between the surface of the third lens element facing the subject and the surface facing the image sensor, D1 / f ≧ 0.294,
The distance D2 between the surface of the fifth lens element facing the subject and the surface facing the image sensor, D2 / f ≧ 0.17,
An imaging lens characterized by The first lens element has a first contact surface at the periphery of the surface facing the imaging element.
The second lens element has a second contact surface contacting the first contact surface at a periphery of a surface facing the subject.
The imaging lens according to claim 1, characterized in that: The first to fifth lens elements are made of glass,
The imaging lens according to claim 1 or 2, characterized in that: Both surfaces of the first to fifth lens elements are spherical.
The imaging lens according to any one of claims 1 to 3, characterized in that: An imaging lens according to any one of claims 1 to 4;
An imaging element on which an object image is formed on an imaging surface by the lens;
A camera equipped with

Images