WO2019107153A1

WO2019107153A1 - Imaging lens, imaging device, and vehicle-mounted camera system

Info

Publication number: WO2019107153A1
Application number: PCT/JP2018/042141
Authority: WO
Inventors: 慶太安田
Original assignee: 京セラ株式会社
Priority date: 2017-11-28
Filing date: 2018-11-14
Publication date: 2019-06-06
Also published as: JPWO2019107153A1; JP6908724B2

Abstract

Through the present invention, by appropriately setting the shape of a lens, an imaging lens is obtained that has high optical performance while being small, lightweight, and inexpensive. The present invention is constituted from, in order to an object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture diaphragm, a third lens having negative refractive power, a fourth lens having positive refractive power, and a fifth lens comprising a union of a lens having positive refractive power and a lens having negative refractive power, all of the lenses being formed by spherical surfaces.

Description

Imaging lens, imaging device, and in-vehicle camera system

Cross-reference to related applications

This application claims the priority of Japanese patent application 2017-227714 (filed on November 28, 2017) and Japanese patent application 2017-228099 (filed on November 28, 2017), The entire disclosure of the application is incorporated herein by reference.

The present invention relates to an imaging lens, an imaging device, and an on-vehicle camera system.

An imaging lens used for a monitoring camera or a vehicle-mounted camera is required to be resistant to environmental changes and have good imaging performance over the entire screen. In addition, because the mounting space is often limited, it is required to be compact and lightweight. For example, imaging lenses used for surveillance cameras or in-vehicle cameras are expected to be used in various areas from the cold zone to the tropics, and in particular the in-vehicle sensing camera, which has been spreading in recent years, has a longer usage time than the rear camera Therefore, an optical system that can be used in a wider temperature range is required. Moreover, the sensing application which detects an object is added from the conventional visual application, and the further performance enhancement is calculated | required. Along with the increase in the number of pixels of an imaging device, good optical performance is required over the entire screen corresponding to it. Furthermore, because of the limited mounting space, it is required to be compact and lightweight.

The following

patent documents

1 and 2 are proposed as a single focus imaging lens which may be able to respond to these demands.

Patent document 1: JP 2008-8960 JP 2013-47753

In recent years, in automotive cameras, sensing applications for detecting an object have been added from conventional viewing applications, and further higher performance has been demanded. In addition, along with the increase in the number of pixels of an imaging device, good optical performance to be compatible with it is required.

The present invention has been made in view of the above points, and an object thereof is to provide an imaging lens having high optical performance while being small, lightweight, and inexpensive. Furthermore, it is an object of the present invention to provide an imaging lens, an imaging apparatus, and an on-vehicle camera system which are small in size, light in weight, inexpensive, have optical performance, and have high weather resistance.

An imaging lens for achieving the above object includes, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and a third lens having negative refractive power , And a fourth lens having positive refractive power, a fifth lens formed by cementing a lens having positive refractive power and a lens having negative refractive power, and all the lenses are formed by spherical surfaces. I assume.

Further, an imaging device for achieving the above object includes, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and a third lens having negative refractive power. Composed of a lens, a fourth lens having a positive refractive power, a fifth lens consisting of a lens having a positive refractive power and a lens having a negative refractive power, all lenses being formed by a spherical surface And an imaging device for converting an optical image formed through the imaging lens into an electrical signal.

Furthermore, an on-vehicle camera system for achieving the above object is provided in a vehicle and includes, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and All lenses are composed of a third lens with refractive power, a fourth lens with positive refractive power, a fifth lens consisting of a lens with positive refractive power and a lens with negative refractive power. The imaging device includes: an imaging lens characterized by having a spherical surface; and an imaging element configured to convert an optical image formed through the imaging lens into an electric signal.

An imaging lens for achieving the above object includes, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and a third lens having negative refractive power. The d-line of a lens having a negative refractive power, which is composed of a lens, a fourth lens having a positive refractive power, a fifth lens consisting of a lens having a positive refractive power and a lens having a negative refractive power, Is characterized in that the following conditional expressions (1) and (2) are satisfied, where dn / dt_n is the average value of the temperature coefficients of relative refractive index in the lens and L45 is the distance between the fourth lens and the fifth lens. Imaging lens.

dn / dt_n ≧ 3.0 (1)
L45 ≧ 0.2 (2)
Further, an imaging device for achieving the above object includes, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and a third lens having negative refractive power. The d-line of a lens having a negative refractive power, which is composed of a lens, a fourth lens having a positive refractive power, a fifth lens consisting of a lens having a positive refractive power and a lens having a negative refractive power, Is characterized in that the following conditional expressions (1) and (2) are satisfied, where dn / dt_n is the average value of the temperature coefficients of relative refractive index in the lens and L45 is the distance between the fourth lens and the fifth lens. An imaging lens, and an imaging device for converting an optical image formed through the imaging lens into an electric signal.

dn / dt_n ≧ 3.0 (1)
L45 ≧ 0.2 (2)
Furthermore, an on-vehicle camera system for achieving the above object is provided in a vehicle and includes, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and Negative refractive power comprising a third lens having a refractive power, a fourth lens having a positive refractive power, a lens having a positive refractive power and a lens having a negative refractive power, and a fifth lens The following conditional expressions (1) and (2) are satisfied, where dn / dt_n is the average temperature coefficient of the relative refractive index at the d-line of the lens having a distance L45 between the fourth lens and the fifth lens: An imaging device including: an imaging lens characterized by; and an imaging device for converting an optical image formed through the imaging lens into an electric signal.

dn / dt_n ≧ 3.0 (1)
L45 ≧ 0.2 (2)

According to the present invention, it is possible to provide a wide-angle imaging lens having a size capable of being mounted in various places such as an automobile etc. and having a high optical performance with good imaging performance over the entire screen while securing a wide field of view. . As a result, it is possible to realize a compact wide-angle imaging lens that can be mounted on a surveillance camera or an on-vehicle camera, and an imaging apparatus using the same.

According to an embodiment of the present invention, it is possible to provide an imaging lens, an imaging device, and an on-vehicle camera system having high optical performance while being small, lightweight, and inexpensive. Furthermore, according to the present invention, it is possible to provide an imaging lens having high weather resistance and optical performance while being small, lightweight and inexpensive. As a result, it is possible to realize an imaging device and an on-vehicle camera system with compact optical performance that can be mounted on a surveillance camera or an on-vehicle camera.

It is a figure which shows the basic composition of an imaging lens. It is a figure showing composition of an imaging lens. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is a figure showing composition of an imaging lens. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is a figure which shows the relationship of the difference of an axial chromatic aberration and the Abbe number of a 5th lens. It is a figure showing composition of an imaging device. It is a figure which shows arrangement | positioning in the vehicle of a vehicle-mounted camera system. It is a figure which shows the basic composition of an imaging lens. It is a figure showing composition of an imaging lens. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is a figure showing composition of an imaging lens. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is a figure showing composition of an imaging lens. It is an aberrational figure which shows spherical aberration. It is an aberrational figure which shows astigmatism. It is an aberrational figure which shows a distortion aberration. It is a figure which shows the relationship between the average value of the temperature coefficient of the relative refractive index in d line of a lens which has negative refractive power, and the focus shift amount in 105 degreeC. It is a figure which shows the relationship between the average value of the temperature coefficient of the relative refractive index in d line of a lens which has negative refractive power, and the focus shift amount in 105 degreeC. It is a figure which shows the relationship between the average value of the temperature coefficient of the relative refractive index in d line of a lens which has negative refractive power, and the focus shift amount in 105 degreeC. It is a figure showing composition of an imaging device. It is a figure which shows arrangement | positioning in the vehicle of a vehicle-mounted camera system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and dimensional ratios and the like in the drawings do not necessarily coincide with actual ones.

The lens configuration of the embodiment is shown in an optical cross section in FIG. In this embodiment, the first lens 110, the second lens 120, the aperture stop 130, the third lens 140, the fourth lens 150, the

fifth lens

160 and 170, a flat plate filter, a flat plate 190, a CCD (Charge Coupled) in this order from the object side. The imaging lens 100 is a five-lens single-focus imaging lens 100 in which an imaging surface 200 serving as a light receiving surface of an imaging element 210 such as a device (Device) or a complementary metal-oxide semiconductor device (CMOS) is disposed.

The flat plate 180 may be a filter with an infrared cut coating or a filter such as a low pass filter. The flat plate 190 may be a cover glass of the imaging device 210.

In the imaging lens according to the present invention, the five lenses include, in order from the object side, a first lens 110 having negative refractive power, a second lens 120 having positive refractive power, an aperture stop 130, and negative refractive power. The third lens 140 is arranged, the fourth lens 150 having positive refractive power, and the

fifth lenses

160 and 170 having positive refractive power. Further, 1 (R1) to 12 (R11) shown in FIG. 1 are surface numbers of the respective constituent requirements.

The aperture stop 130 is disposed between the second lens 120 and the third lens 140. Disposing the aperture stop 130 closer to the image than the

fifth lens

160 or 170 is undesirable because the lens system becomes larger, and placing it between the first lens 110 and the second lens 120 increases the back focus. It is not preferable because it is disadvantageous. Therefore, by disposing between the second lens 120 and the third lens 140 described above, it is possible to correct various aberrations and to make the lens system compact.

Correction of axial chromatic aberration is facilitated by joining the

fifth lens

160 and 170 with a lens having positive refractive power and a lens having negative refractive power.

All the lenses are spherical surfaces, which makes them easy to manufacture. In addition, optical performance deterioration due to tolerance can be reduced by not using an aspheric surface.

The imaging lens 100 according to the present invention has the following conditional expression (1), where ベ a is the Abbe number of the lens 160 having the positive refractive power of the fifth lens, and アッ b is the Abbe number of the lens 170 having negative refractive power. To be satisfied).

30 ν a a-b b 17 17 (1)
Conditional expression (1) relates the difference between Abbe numbers of the lens 160 having a positive refractive power of the fifth lens and the lens 170 having a negative refractive power. If the lower limit value of the conditional expression (1) is exceeded, the difference in Abbe number is too small, which makes it difficult to correct axial chromatic aberration due to negative refraction. On the other hand, if the upper limit value is exceeded, the occurrence of axial chromatic aberration due to negative refraction is too large, and the correction becomes excessive.

The imaging lens 100 is preferably configured to satisfy the conditional expression (2).

2 W 50 50 ° (2)
Here, 2W is the total angle of view of the light beam incident on the maximum image height position on the imaging plane.

Conditional expression (2) relates to the angle of view of the entire imaging lens system. If the lower limit value of the conditional expression (2) is exceeded, it will be difficult to secure a photographing range to be satisfied as an on-vehicle camera.

The imaging lens 100 preferably has an Abbe number of 30 or less for the d-line of the material forming the third lens 140, and an Abbe number of 30 or more for the d-line of the material of the fourth lens 150. Ru.

As a result, the smaller the Abbe number to the d-line of the material forming the third lens 140 of the negative lens, the smaller the axial chromatic aberration. On the other hand, as the Abbe number to the d-line of the material forming the fourth lens 150 of the positive lens is larger, the longitudinal chromatic aberration can be corrected better.

Preferably, the first lens 110 has a concave surface on the image side, the second lens 120 has a convex surface on the object side, and the fifth lens 160 has a convex surface on the object side.

Thereby, in the first lens 110, by directing the concave surface to the image side, it becomes possible to enter light from the object side at a wide angle of view. By directing the convex surface to the object side in the second lens 120, the ghost generated on the image side surface of the first lens 110 is not collected. The fifth lens 160 focuses the light incident at a wide angle of view by directing the convex surface to the object side.

Further, it is preferable that all the lenses from the first lens 110 to the fifth lens 170 be formed of a glass material.

Thereby, it is possible to suppress the change in optical characteristics due to the temperature change.

Further, when the focal length of the first lens 110 is f1, the focal length of the third lens 140 is f3, and the focal length of the imaging lens 100 is f, the following conditional expressions (3) to (4) are satisfied. Be done.

-1.95 <f1 / f <-1.55 (3)
-1.3 <f 3 / f <-0.9 (4)
Conditional expression (3) relates the focal length of the first lens 110 to the focal length of the imaging lens 100. When the lower limit value of the conditional expression (3) is exceeded, it becomes difficult to enter light from the object side at a wide angle of view, and when the upper limit value is exceeded, the curvature radius of the L1R2 surface becomes too small, which makes manufacturing difficult It becomes. Conditional expression (4) relates the focal length of the third lens 140 to the focal length of the imaging lens 100. If the lower limit value of the conditional expression (4) is exceeded, the power of the third lens 140 is too small to correct axial chromatic aberration, and if the upper limit is exceeded, the power of the third lens 140 is too large. Correction will be excessive.

Hereinafter, Examples 1 to 4 and Reference Examples 1 to 2 will be shown according to specific numerical values of the imaging lens 100. In the numerical examples of Examples 1 to 4 and Reference Examples 1 to 2, the focal length, the F value, the image height, and the total lens length are as described in Table 1 below. Similarly, in the numerical examples of Examples 1 to 4 and Reference Examples 1 and 2, numerical data of the conditional expressions (1) to (4) have values described in Table 2 below.

Example 1
The basic configuration of the imaging lens 100A in the first embodiment is shown in FIG. 2, each numerical data (setting value) is shown in Table 3, and an aberration chart showing spherical aberration, distortion and astigmatism is shown in FIG. Be

As shown in FIG. 2, the first lens 110 has a meniscus shape with a convex surface facing the object side, the second lens 120 has a biconvex shape, the third lens 140 disposed on the image side of the aperture stop 130 has a biconcave shape, The fourth lens 150 has a biconvex shape, the fifth lens 160 has a biconvex shape, and the fifth lens 170 has a meniscus shape with a concave surface facing the object side.

Further, as shown in FIG. 2, the distance between the R1 surface 1 and the R2 surface 2 which is the thickness of the first lens 110 is D1, and the distance between the R2 surface 2 of the first lens 110 and the R3 surface 3 of the second lens 120. The distance between the R3 surface 3 and the R4 surface 4 which is the thickness of the second lens 120 is D3, the distance between the R4 surface 4 of the second lens 120 and the surface 5 of the aperture stop 130 is D4, the surface of the aperture stop 130 The distance between the fifth lens 5 and the R5 surface 6 of the third lens 140 is D5, and the distance between the R5 surface 6 and the R6 surface 7 which is the thickness of the third lens 140 is D6. The R6 surface 7 of the third lens 140 and the fourth lens 150 The distance between the R7 surface 8 and the R8 surface 9 which is the thickness of the fourth lens 150 is D7. The distance between the R8 surface 9 of the fourth lens 150 and the R9 surface 10 of the fifth lens 160 is D8. R9 surface 10 and R1 that have a distance of D9 and the thickness of the fifth lens 160 The distance between the 0 surface 11 is D10, the distance between the R10 surface 11 and the R11 surface 12 is the thickness of the fifth lens 170 is D11, and the distance between the R11 surface 12 of the fifth lens 170 and the surface 13 of the flat plate 180 is D12, The distance between the surface 13 and the surface 14 which is the thickness of the flat plate 180 is D13, the distance between the surface 14 of the flat plate 180 and the surface 15 of the flat plate 190 is D14, and the distance between the surface 15 and the plane 16 which is the thickness of the flat plate 190 is D15. The distance between the surface 16 of the flat plate 190 and the imaging surface 200 is D16. In Examples 2 to 4 and Reference Examples 1 to 2 below, R1 surface 1 to surface 16 and D1 to D16 mean the same distance.

Table 3 shows the stop corresponding to each surface number of the imaging lens 100A in Example 1, the curvature radius R of each lens, the distance D, the refractive index Nd, and the dispersion value dd.
Numerical embodiment 1

3 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) and FIG. 3B shows astigmatic aberration (solid line: from left: 435.8 nm, 486.1 nm) in Example 1; , 546.1 nm, 587.6 nm, 656.3 nm sagittal ray, dotted line: left from 435.8 nm, 486.1 nm, 546.1 nm, 546.1 nm, 587.6 nm, 656.3 nm tangential ray), and FIG. 3C shows distortion aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm and 656.3 nm are shown respectively). The vertical axes in FIGS. 3B and 3C represent the half angle of view ω, and in FIG. 3B, the solid line S represents the value of the sagittal image plane, and the broken line T represents the value of the tangential image plane (FIGS. The same applies to 11). As can be seen from FIG. 3, according to Example 1, various aberrations such as spherical surface, distortion and astigmatism are corrected well, and an imaging lens 100A having excellent imaging performance can be obtained.

Example 2
The basic configuration of the imaging lens 100B according to Embodiment 2 is shown in FIG. 4, each numerical data (setting value) is shown in Table 4, and an aberration diagram showing spherical aberration, distortion and astigmatism is shown in FIG. Be

As shown in FIG. 4, the first lens 110 has a meniscus shape with a convex surface facing the object side, the second lens 120 has a biconvex shape, the third lens 140 disposed on the image side of the aperture stop 130 has a biconcave shape, The fourth lens 150 has a biconvex shape, the fifth lens 160 has a biconvex shape, and the fifth lens 170 has a meniscus shape with a concave surface facing the object side.

Table 4 shows the stop corresponding to each surface number of the imaging lens 100B in Example 2, the radius of curvature R of each lens, the interval D, the refractive index Nd, and the dispersion value dd.
Numerical embodiment 2

FIG. 5 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) in FIG. 5A and astigmatism in FIG. 5B (solid line: from left: 435.8 nm, 486.1 nm) , 546.1 nm, 587.6 nm, 656.3 nm sagittal ray, dotted line: left from 435.8 nm, 486.1 nm, 546.1 nm, 546.1 nm, 587.6 nm, 656.3 nm tangential ray), and FIG. 5C shows distortion aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm and 656.3 nm are shown respectively). As can be seen from FIG. 5, according to the second embodiment, various aberrations such as spherical surface, distortion and astigmatism are corrected well, and an imaging lens 100B excellent in imaging performance is obtained.

Example 3
Numerical data (setting values) in the third embodiment are shown in Table 5, and aberration diagrams showing spherical aberration, distortion and astigmatism are shown in FIG. 6, respectively.

Table 5 shows the stop corresponding to each surface number of the imaging lens in Example 3, the curvature radius R of each lens, the interval D, the refractive index Nd, and the dispersion value dd.
Numerical embodiment 3

6 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) and FIG. 6B shows astigmatic aberration (solid line: from left: 435.8 nm, 486.1). nm, 546.1 nm, 587.6 nm, 656.3 nm, sagittal light beam, dotted line: left from 435.8 nm, 486.1 nm, 546.1 nm, 547.6 nm, 587.6 nm, 656.3 nm tangential light), and FIG. 6C shows distortion aberration (435.8 nm, 486.1 nm) , 546.1 nm, 587.6 nm, and 656.3 nm), respectively. As can be seen from FIG. 6, according to the third embodiment, various aberrations such as spherical surface, distortion and astigmatism are corrected well, and an imaging lens having excellent imaging performance can be obtained.

Example 4
Numerical data (setting values) in the fourth embodiment are shown in Table 6, and aberration diagrams showing spherical aberration, distortion and astigmatism are shown in FIG. 7, respectively.

Table 6 shows the stop corresponding to each surface number of the imaging lens in Example 4, the curvature radius R of each lens, the distance D, the refractive index Nd, and the dispersion value dd.
Numerical embodiment 4

FIG. 7 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) in FIG. 7A and astigmatism in FIG. 7B (solid line from left: 435.8 nm, 486.1). nm, 546.1 nm, 587.6 nm, 656.3 nm sagittal ray, dotted line: left from 435.8 nm, 486.1 nm, 546.1 nm, 546.1 nm, 587.6 nm, 656.3 nm tangential ray), distortion is shown in FIG. 7C (435.8 nm, 486.1 nm) , 546.1 nm, 587.6 nm, and 656.3 nm), respectively. As can be seen from FIG. 7, according to Example 4, various aberrations such as spherical surface, distortion and astigmatism are corrected well, and an imaging lens having excellent imaging performance can be obtained.

Reference Example 1
Numerical data (setting values) in the fifth embodiment are shown in Table 7, and aberration diagrams showing spherical aberration, distortion and astigmatism are shown in FIG. 8, respectively.

Table 7 shows the stop corresponding to each surface number of the imaging lens in the reference example 1, the curvature radius R of each lens, the interval D, the refractive index Nd, and the dispersion value dd.
Numerical reference example 1

FIG. 8 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) and astigmatic aberration (solid line: from left: 435.8 nm, 486.1 nm). Sagittal light beam, 546.1 nm, 587.6 nm, 656.3 nm, dotted line: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm tangential light beam from the left, and FIG. 8C shows distortion aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm and 656.3 nm are shown respectively).

Reference Example 2
Numerical data (setting values) in the sixth embodiment are shown in Table 8, and aberration diagrams showing spherical aberration, distortion and astigmatism are shown in FIG. 9, respectively.

Table 8 shows the stop corresponding to each surface number of the imaging lens in the reference example 2, the curvature radius R of each lens, the distance D, the refractive index Nd, and the dispersion value dd.
Numerical reference example 2

9 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) in FIG. 9A, and FIG. 9B shows astigmatism (solid line: 435.8 nm from left, 486.1 nm). , 546.1 nm, 587.6 nm, 656.3 nm, sagittal light beam, dotted line: left from 435.8 nm, 486.1 nm, 546.1 nm, 547.6 nm, 587.6 nm, 656.3 nm tangential light), distortion aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm and 656.3 nm are shown respectively).

FIG. 10 shows the relationship between axial chromatic aberration and the Abbe's number difference of the fifth lens in each of the first to fourth embodiments and the first and second embodiments. As can be seen from FIG. 10, by setting the difference in Abbe number within a specific range, it is possible to suppress axial chromatic aberration to a small value. In order to correct axial chromatic aberration well, it is necessary to make it 0.05 or less, and the difference in Abbe number is 30 となる va−vbν17.

As mentioned above, although the imaging lens concerning this embodiment was demonstrated, this invention is not limited to the imaging lens of these Examples, A various deformation | transformation is possible in the range which does not deviate from the summary of invention. For example, the specifications of the imaging lens 100 of Examples 1 to 4 are exemplification, and various parameter changes are possible within the scope of the present invention. In the above embodiment, the cover glass (flat plate) 190 may be provided with an infrared ray removing filter, or an infrared cut coat may be applied to the surface of the cover glass (flat plate) 190. Also, infrared coating may be applied to other lens surfaces or filters such as low pass filters.

According to this embodiment, a wide-angle imaging lens can be provided which can be mounted in various places such as a monitoring camera or a car-mounted camera, has a wide field of view, has good imaging performance over the entire screen, and has high optical performance. .

FIG. 11 shows a cross-sectional view of an embodiment of an imaging device 210 using the imaging lens 100 according to an embodiment of the present invention. The imaging lens 100 and an imaging element 210 such as a CCD or CMOS are defined and held in a positional relationship by a housing 220. At this time, the imaging surface 200 of the imaging lens 100 is disposed to coincide with the light receiving surface of the imaging element 210.

An object image captured by the imaging lens 100 and formed on the light receiving surface of the imaging element 210 is converted into an electrical signal by the photoelectric conversion function of the imaging element 210 and output from the imaging element 210 as an image signal.

FIG. 12 is a view for explaining an example of an on-vehicle camera system in which the imaging device 300 using the imaging lens 100 according to an embodiment of the present invention is applied to an on-vehicle camera 410 mounted on a vehicle 400. The on-vehicle camera system includes an on-vehicle camera 410 and an image processing device 420. The on-vehicle camera 410 can be attached to the interior or the exterior of the vehicle 400 and can image a predetermined direction, but in the example of FIG. An image shall be taken.

The on-vehicle camera 410 outputs the acquired image to the image processing apparatus 420 via the communication unit in the vehicle 400. The image processing device 420 includes an image processing ASIC (Application Specific Integrated Circuit), a processor dedicated to image processing such as a DSP (Digital Signal Processor), and a memory for storing various information, and is output from the on-vehicle camera 410 and other on-vehicle cameras Processing such as white balance adjustment, exposure adjustment processing, color interpolation, brightness correction, and gamma correction is performed on the captured image. Furthermore, the image processing device 420 performs processing such as switching of images, combining of images from a plurality of in-vehicle cameras, clipping of a part of images, superimposing on images such as symbols, characters or expected trajectory lines, etc. It outputs an image signal according to the specifications of the device 430. The on-vehicle camera 410 may have some or all of the functions of the image processing apparatus 420.

The display device 430 is disposed on a dashboard or the like of the vehicle 400, and displays the image information processed by the image processing device 420 to the driver of the vehicle 400.

As described above, although the imaging lens 100 is a wide-angle imaging lens, the occurrence of distortion can be reduced, an object image with high optical performance can be formed on the light receiving surface of the imaging element 210, and the visibility is excellent. It is possible to output an image signal of an image. Furthermore, axial chromatic aberration can be suppressed even if the wavelength band is extended to near infrared light in order to be used in an environment where light intensity is low such as nighttime. It is suitable for the camera 410. Furthermore, since the device can be made compact and lightweight, the mounting space can be made compact, which is suitable for the imaging device 210 for various applications.

Hereinafter, another embodiment of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and dimensional ratios and the like in the drawings do not necessarily coincide with actual ones.

The lens configuration of the embodiment is shown in an optical cross section in FIG. In this embodiment, a first lens 1110, a second lens 1120, an aperture stop 1130, a third lens 1140, a fourth lens 1150, a

fifth lens

1160 and 1170, a flat plate 1180, a flat plate 1190, and a CCD (Charge Coupled) from the object side. The imaging lens 1100 is a five-lens single-focus imaging lens 1100 in which an imaging surface 1200 serving as a light receiving surface of an imaging element 1210 such as a device (Device) or a complementary metal-oxide semiconductor device (CMOS) is disposed.

In the imaging lens according to the present invention, the five lenses include, in order from the object side, a first lens 1110 having negative refractive power, a second lens 1120 having positive refractive power, an aperture stop 1130, and negative refractive power. The third lens 1140, the fourth lens 1150 having a positive refractive power, and the

fifth lens

1160 or 1170 having a positive refractive power are arranged. Further, 1 (R1) to 12 (R11) shown in FIG. 13 are surface numbers of respective constituent requirements.

The aperture stop 1130 is disposed between the second lens 1120 and the third lens 1140. Disposing the aperture stop 1130 closer to the image than the fifth lens 1160-1170 is not preferable because the lens system becomes larger, and placing it between the first lens 1110 and the second lens 1120 increases the back focus. It is not preferable because it is disadvantageous. Therefore, by disposing between the second lens 1120 and the third lens 1140 described above, satisfactory correction of various aberrations and downsizing of the lens system become possible.

The fifth lens 1160-1170 is a cement of a lens having a positive refractive power and a lens having a negative refractive power, so that correction of axial chromatic aberration is facilitated.

The imaging lens 1100 embodying the present invention has an average value of the temperature coefficient of the relative refractive index at the d-line of the lens having negative refractive power, dn / dt_n, and the distance between the fourth lens 1150 and the fifth lens 1160 · 1170. When L 45 is L 45, the following conditional expressions (5) and (6) are satisfied.

dn / dt_n ≧ 3.0 (5)
L45 ≧ 0.2 (6)
Conditional expression (5) is an expression relating to the average value of the temperature coefficients of the relative refractive index at the d-line of the first lens 1110 having a negative refractive power, the third lens 1130, and the fifth lens 1170. When the temperature is high, the glass lens usually changes in the direction in which the refractive power increases. However, when the lower limit value of the conditional expression (5) is exceeded, it is difficult to change in the direction in which the refractive power of the lens having negative refractive power increases. The focus shifts to the object side. Conditional expression (6) is an expression related to the distance between the fourth lens 1150 and the fifth lens 1160-1170. If the lower limit value of the conditional expression (6) is exceeded, a general manufacturing tolerance of 20 μm occupies 10% or more of the design value, which makes manufacturing difficult.

The imaging lens 1100 is preferably configured to satisfy the conditional expression (7).

2W ≧ 50 ° (7)
Here, 2W is the total angle of view of the light beam incident on the maximum image height position on the imaging plane.

Conditional expression (7) is an expression regarding the angle of view of the imaging lens 1100. If the lower limit value of the conditional expression (7) is exceeded, it will be difficult to secure a photographing range to be satisfied as an on-vehicle sensing camera.

Further, it is preferable that the first lens 1110 has a concave surface on the image side, the second lens 1120 has a convex surface on the object side, and the fifth lens 1160 has a convex surface on the object side.

As a result, with the first lens 1110, light from the object side can be incident at a wide angle of view by directing the concave surface toward the image side. By directing the convex surface to the object side in the second lens 1120, the ghost generated on the image side surface of the first lens 1110 is not collected. The fifth lens 1160 focuses light incident at a wide angle of view by directing the convex surface toward the object side.

In addition, it is preferable that all the lenses from the first lens 1110 to the fifth lens 1170 be formed of a glass material.

Thereby, the transmittance | permeability fall by yellowing can be suppressed.

The imaging lens 1100 is preferably configured to satisfy the conditional expression (8).

dn / dt_p ≦ 4.0 (8)
However, dn / dt_p shows the average value of the temperature coefficient of the relative refractive index at the d-line of the lens having positive refractive power.

Conditional expression (8) relates to the average value of the temperature coefficient of the relative refractive index at the d-line of the second lens 1120 having a positive refractive power, the fourth lens 1150, and the fifth lens 1170. If the upper limit value of the conditional expression (8) is exceeded, the refractive power of the lens having positive refractive power becomes too large at high temperature, and the focus shifts to the object side.

The fourth lens 1150 preferably has an aspheric shape on one side or both sides.

As a result, aberration correction becomes easy, and it becomes possible to obtain good resolution performance while being compact.

In addition, when the focal length of the first lens 1110 is f1, the focal length of the third lens 1140 is f3, and the focal length of the imaging lens 1100 is f, the following conditional expressions (9) to (10) are satisfied. Be done.

-1.8 <f1 / f <-1.3 (9)
-1.4 <f3 / f <-1.0 (10)
Conditional expression (9) relates the focal length of the first lens 1110 to the focal length of the imaging lens 1100. When the lower limit value of the conditional expression (9) is exceeded, it becomes difficult to enter light from the object side at a wide angle of view, and when the upper limit value is exceeded, the curvature radius of the L1R2 surface becomes too small, which makes manufacturing difficult It becomes. Conditional expression (10) relates the focal length of the third lens 1140 to the focal length of the imaging lens 1100. If the lower limit value of the conditional expression (10) is exceeded, the power of the third lens 1140 is too small to correct axial chromatic aberration. If the upper limit is exceeded, the power of the third lens 1140 is too large. Correction will be excessive.

As for the shape of the aspheric surface of the lens described in the following numerical examples, the direction from the object side to the image plane side is positive, k is a conical coefficient, A is a fourth-order aspheric coefficient, B Is a sixth order aspheric coefficient, C is an eighth order aspheric coefficient, and D is a tenth order aspheric coefficient. h is the height of the ray, c is the reciprocal of the central radius of curvature, and Z is the depth from the tangent to the surface vertex.

Examples 5 to 10 and reference examples 3 to 5 will be shown below by using specific numerical values of the imaging lens 100. In the numerical examples of Examples 5 to 10 and Reference Examples 3 to 5, the focal length, the f-number, the image height, and the total lens length are as described in Table 9 below. Similarly, in the numerical examples of the embodiments 5 to 10 and the reference examples 3 to 5, the numerical data of the conditional expressions (5) to (10) have the values described in Table 10 below.

Example 5
The basic configuration of the imaging lens 1100A in the seventh embodiment is shown in FIG. 14, each numerical data (setting value) is shown in Table 11, and an aberration diagram showing spherical aberration, distortion and astigmatism is shown in FIG. Be

As shown in FIG. 14, the first lens 1110 has a meniscus shape with a convex surface facing the object side, the second lens 1120 has a biconvex shape, and the third lens 1140 disposed on the image side of the aperture stop 1130 has a biconcave shape, The fourth lens 1150 has a biconvex shape, the fifth lens 1160 has a biconvex shape, and the fifth lens 1170 has a meniscus shape with a concave surface facing the object side.

Further, as shown in FIG. 14, the distance between the R1 surface 1 and the R2 surface 2 which is the thickness of the first lens 1110 is D1, and the distance between the R2 surface 2 of the first lens 1110 and the R3 surface 3 of the second lens 1120 The distance between the R3 surface 3 and the R4 surface 4 which is the thickness of the second lens 1120 is D3, the distance between the R4 surface 4 of the second lens 1120 and the surface 5 of the aperture stop 1130 is D4, the surface of the aperture stop 1130 The distance between the fifth lens 513 and the R5 6 of the third lens 1140 is D5, the distance between the R5 6 and the R6 7 is the thickness of the third lens 1140 D6, the R6 7 of the third lens 1140 and the fourth lens 1150 The distance between the R7 surface 8 and the R8 surface 9 which is the thickness of the fourth lens 1150 is D7. The distance between the R8 surface 9 of the fourth lens 1150 and the R9 surface 10 of the fifth lens 1160 is D8. Distance D9, fifth lens 1 The distance between the R9 surface 10 and the R10 surface 11 with a thickness of 60 is D10, the distance between the R10 surface 11 and the R11 surface 12 with a thickness of the fifth lens 1170 is D11, the R11 surface 12 of the fifth lens 1170 and the flat plate 1180 The distance between the surface 13 and the surface 14 which is the thickness of the flat plate 1180 is D13, the distance between the surface 14 of the flat plate 1180 and the surface 15 of the flat plate 1190 is D14, the surface which is the thickness of the flat plate 1190 The distance between the surface 15 and the surface 16 is D15, and the distance between the surface 16 of the flat plate 1190 and the imaging surface 1200 is D16. Also in the following Examples 6 to 10 and Reference Examples 3 to 4, R1 surface 1 to surface 16 and D1 to D16 mean the same distance.

Table 11 shows the diaphragms corresponding to the surface numbers of the imaging lens 1100A in Example 5, curvature radius R (mm) of each lens, distance D (mm), refractive index Nd, dispersion value 分散 d, relative refractive index at d-line Temperature coefficient dn / dt and linear expansion coefficient α. Surfaces with * in Table 11 indicate that they have an aspherical shape. Table 12 shows the aspheric coefficients of the predetermined surface.
Numerical embodiment 5

FIG. 15 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) in FIG. 15A and astigmatism in FIG. 15B (solid line: from 43.58 nm, 486.1 nm from left) Sagittal light beam, 546.1 nm, 587.6 nm, 656.3 nm, dotted line: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm tangential light beam from the left, distortion aberration in FIG. 15C (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm and 656.3 nm are shown respectively). The vertical axes in FIGS. 15B and 15C represent the half angle of view ω, and in FIG. 15B, the solid line S represents the value of the sagittal image plane, and the broken line T represents the value of the tangential image plane (FIGS. 17, 19 and 21). The same applies to (23). As can be seen from FIG. 15, according to the fifth embodiment, various aberrations such as spherical surface, distortion and astigmatism are corrected well, and an imaging lens 1100A excellent in imaging performance is obtained.

Example 6
The basic configuration of the imaging lens and the aberration diagram showing spherical aberration, distortion, and astigmatism in the eighth embodiment are the same as in the fifth embodiment. Each numerical data (setting value) is shown in Table 13.

Table 13 shows the stop corresponding to each surface number of the imaging lens in Example 6, curvature radius R (mm) of each lens, distance D (mm), refractive index Nd, dispersion value dd, relative refractive index at d-line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. Surfaces with * in Table 13 indicate that they have an aspheric shape. Table 14 shows the aspheric coefficients of the predetermined surface.
Numerical embodiment 6

Example 7
The basic configuration of the imaging lens 1100B in the ninth embodiment is shown in FIG. 16, each numerical data (setting value) is shown in Table 15, and aberration diagrams showing spherical aberration, distortion and astigmatism are shown in FIG. Be

As shown in FIG. 16, the first lens 1110 has a meniscus shape with a convex surface facing the object side, the second lens 1120 has a double convex shape, the third lens 1140 disposed on the image side of the aperture stop 1130 has a double concave shape, The fourth lens 1150 has a biconvex shape, the fifth lens 1160 has a biconvex shape, and the fifth lens 1170 has a biconvex shape.

Table 15 shows the stop corresponding to each surface number of the imaging lens in Example 7, curvature radius R (mm) of each lens, distance D (mm), refractive index Nd, dispersion value dd, relative refractive index at d-line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. The surface indicated by * in Table 15 indicates that the surface has an aspherical shape. Table 16 shows the aspheric coefficients of the predetermined surface.
Numerical embodiment 7

FIG. 17 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) in FIG. 17A and astigmatism in FIG. 17B (solid line from left: 435.8 nm, 486.1). nm, 546.1 nm, 587.6 nm, 656.3 nm, sagittal ray, dotted line: left from 435.8 nm, 486.1 nm, 546.1 nm, 546.1 nm, 587.6 nm, 656.3 nm, tangential ray), and FIG. 17C shows distortion aberration (435.8 nm, 486.1 nm) , 546.1 nm, 587.6 nm, and 656.3 nm), respectively. As can be seen from FIG. 17, according to the seventh embodiment, various aberrations of spherical surface, distortion and astigmatism are corrected well, and an imaging lens excellent in imaging performance can be obtained.

Example 8
The basic configuration of the imaging lens and the aberration diagram showing spherical aberration, distortion, and astigmatism in the tenth embodiment are the same as in the seventh embodiment. Each numerical data (setting value) is shown in Table 17.

Table 17 shows the stop corresponding to each surface number of the imaging lens in Example 7, curvature radius R (mm) of each lens, distance D (mm), refractive index Nd, dispersion value dd, relative refractive index at d-line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. Surfaces with * in Table 17 indicate that they have an aspheric shape. Table 18 shows the aspheric coefficients of the predetermined surface.
Numerical embodiment 8

Example 9
The basic configuration of the imaging lens 1100C according to Embodiment 11 is shown in FIG. 18, each numerical data (setting value) is shown in Table 19, and an aberration diagram showing spherical aberration, distortion and astigmatism is shown in FIG. Be

As shown in FIG. 18, the first lens 1110 has a meniscus shape with a convex surface facing the object side, the second lens 1120 has a double convex shape, the third lens 1140 disposed on the image side of the aperture stop 1130 has a double concave shape, The fourth lens 1150 has a biconvex shape, the fifth lens 1160 has a biconvex shape, and the fifth lens 1170 has a biconvex shape.

Table 19 shows the diaphragms corresponding to the surface numbers of the imaging lens in Example 9, curvature radius R (mm) of each lens, distance D (mm), refractive index Nd, dispersion value 分散 d, and relative refractive index at d-line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. Surfaces with * in Table 19 indicate that they have an aspherical shape. Table 20 shows the aspheric coefficients of the predetermined surface.
Numerical embodiment 9

19 shows spherical aberration (from left: 435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm) and FIG. 19B shows astigmatism (solid line: from left: 435.8 nm, 486.1) in Example 9; nm, 546.1 nm, 587.6 nm, 656.3 nm, sagittal light beam, dotted line: left from 435.8 nm, 486.1 nm, 546.1 nm, 547.6 nm, 587.6 nm, 656.3 nm tangential light), and FIG. 19C shows distortion aberration (435.8 nm, 486.1 nm) , 546.1 nm, 587.6 nm, and 656.3 nm), respectively. As can be seen from FIG. 19, according to Example 9, various aberrations such as spherical surface, distortion and astigmatism are corrected well, and an imaging lens having excellent imaging performance can be obtained.

Example 10
The basic configuration of the imaging lens and the aberration diagram showing spherical aberration, distortion, and astigmatism in Embodiment 12 are the same as in Embodiment 9. Each numerical data (set value) is shown in Table 21. Table 21 shows the stop corresponding to each surface number of the imaging lens in Example 9, curvature radius R (mm) of each lens, distance D (mm), refractive index Nd, dispersion value dd, relative refractive index at d-line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. Surfaces with * in Table 21 indicate that they have an aspheric shape. Table 22 shows the aspheric coefficients of the predetermined surface.
Numerical embodiment 10

Reference Example 3
Numerical data (setting values) in the thirteenth embodiment are shown in Table 17.

Table 23 shows the stop corresponding to each surface number of the imaging lens in the reference example 3, the curvature radius R (mm) of each lens, the distance D (mm), the refractive index Nd, the dispersion value dd, and the relative refractive index at the d line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. Surfaces with * in Table 23 indicate that they have an aspherical shape. Table 24 shows the aspheric coefficients of the predetermined surface.
Numerical reference example 3

Reference Example 4
Numerical data (setting values) in the fourteenth embodiment are shown in Table 25.

Table 25 shows the stop corresponding to each surface number of the imaging lens in the reference example 4, the curvature radius R (mm) of each lens, the distance D (mm), the refractive index Nd, the dispersion value νd, and the relative refractive index at the d line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. The surface indicated by * in Table 25 indicates that the surface has an aspheric shape. Table 26 shows the aspheric coefficients of the predetermined surface.
Numerical reference example 4

Reference Example 5
Numerical data (setting values) in the fifteenth embodiment are shown in Table 27.

Table 27 shows the stop corresponding to each surface number of the imaging lens in the reference example 5, the curvature radius R (mm) of each lens, the distance D (mm), the refractive index Nd, the dispersion value dd, and the relative refractive index at the d line The temperature coefficient dn / dt and the linear expansion coefficient α are shown. Surfaces with * in Table 27 indicate that they have an aspherical shape. Table 28 shows the aspheric coefficients of the predetermined surface.
Numerical reference example 5

20, 21 and 22 show the d-line of the first lens 1110, the third lens 1130, and the fifth lens 1170 having negative refractive power in Example 5 to Example 10 and Reference Example 3 to Reference Example 5, respectively. The relationship between the average value of the temperature coefficient of the relative refractive index and the focus shift amount at 105 ° C. is shown. The focus shift amount is calculated from the temperature coefficient of the relative refractive index at the d-line and the linear expansion coefficient.
As can be seen from FIGS. 20, 21, and 22, by setting the average value of the temperature coefficients of relative refractive indices to a specific value or more, the amount of focus shift can be suppressed to a small value. The focus shift amount needs to be 10 μm or less due to manufacturing tolerances, and the average value of the temperature coefficient of the relative refractive index at the d-line of a lens having negative refractive power is dn / dt_n ≧ 3.0.

As mentioned above, although the imaging lens concerning this embodiment was demonstrated, this invention is not limited to the imaging lens of these Examples, A various deformation | transformation is possible in the range which does not deviate from the summary of invention. For example, the specifications of the imaging lens 1100 of Examples 5 to 8 are exemplification, and various parameter changes are possible within the scope of the present invention. Further, in the above embodiment, an infrared ray removing filter may be provided on the cover glass (flat plate) 1190, or an infrared cut coat may be applied to the surface of the cover glass (flat plate) 1190. Also, infrared coating may be applied to other lens surfaces or filters such as low pass filters.

FIG. 23 shows a cross-sectional view of an embodiment of an imaging device 1300 using an imaging lens 1100 according to an embodiment of the present invention. An imaging lens 1100 and an imaging element 1210 such as a CCD or CMOS are defined and held in a positional relationship by a housing 1220. At this time, the imaging surface 1200 of the imaging lens 1100 is disposed to coincide with the light receiving surface of the imaging element 1210.

An object image captured by the imaging lens 1100 and formed on the light receiving surface of the imaging element 1210 is converted into an electrical signal by the photoelectric conversion function of the imaging element 1210 and output from the imaging element 1210 as an image signal.

FIG. 24 is a view for explaining an example of an on-vehicle camera system in which an imaging device 1300 using an imaging lens 1100 according to an embodiment of the present invention is applied to an on-vehicle camera 1410 mounted on a vehicle 1400. The on-vehicle camera system includes an on-vehicle camera 1410 and an image processing device 1420. The on-vehicle camera 1410 is attached to the interior or the exterior of the vehicle 1400 and can capture a predetermined direction, but in the example of FIG. An image shall be taken.

The on-vehicle camera 1410 outputs the acquired image to the image processing apparatus 1420 via the communication unit in the vehicle 1400. The image processing apparatus 1420 includes an image processing ASIC (Application Specific Integrated Circuit), a processor dedicated to image processing such as a DSP (Digital Signal Processor), and a memory for storing various information, and is output from the onboard camera 1410 and other onboard cameras Processing such as white balance adjustment, exposure adjustment processing, color interpolation, brightness correction, and gamma correction is performed on the captured image. Furthermore, the image processing device 1420 performs processing such as switching of images, combining of images from a plurality of in-vehicle cameras, cutting out of some images, superimposing on images such as symbols, characters or expected trajectory lines, etc. An image signal according to the specifications of the device 1430 is output. The on-vehicle camera 1410 may have some or all of the functions of the image processing apparatus 1420.

The display device 1430 is disposed on a dashboard or the like of the vehicle 1400, and displays the image information processed by the image processing device 1420 to the driver of the vehicle 1400.

As described above, although the imaging lens 1100 is a wide-angle imaging lens, the occurrence of distortion can be reduced, and an object image with high optical performance can be formed on the light receiving surface of the imaging element 1210, and the visibility is excellent. It is possible to output an image signal of an image. Furthermore, axial chromatic aberration can be suppressed even if the wavelength band is extended to near infrared light in order to be used in an environment where the amount of light is low, such as at night, and in particular, an on-vehicle using an imaging element 1210 without an infrared cut filter It is suitable for the camera 1410. Furthermore, since the device can be made compact and lightweight, the mounting space can be made compact, which is suitable for the imaging device 1210 for various applications.

100, 100A to 100B imaging lens 110 first lens 120 second lens 130 aperture stop 140 third lens 150 fourth lens 160 fifth lens 170 fifth lens 180 flat plate 190 flat plate 200 imaging surface 210 imaging element 220 frame 300 imaging device 400 vehicle 410 vehicle-mounted camera 420 image processing device 430

display device

1100, 1100A to 1100C imaging lens 1110 first lens 1120 second lens 1130 aperture stop 1140 third lens 1150 fourth lens 1160 fifth lens 1170 fifth lens 1180 flat plate 1190 flat plate 1200 image forming plane 1210 imaging device 1220 housing 1300 imaging device 1400 vehicle 1410 in-vehicle camera 1420 image processing device 1430 display device

Claims

From the object side, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, a third lens having negative refractive power, and a fourth lens having positive refractive power An imaging lens comprising: a lens; a lens having a positive refracting power; and a fifth lens formed by cementing a lens having a negative refracting power, wherein all the lenses are formed by a spherical surface.
When the Abbe number of the lens having positive refractive power of the fifth lens is aa and the Abbe number of the lens having negative refractive power is νb, the following conditional expression (1) is satisfied: The imaging lens according to 1.
30 ν a a-b b 17 17 (1)
The imaging lens according to any one of claims 1 to 2, wherein the following conditional expression (2) is satisfied.
2 W 50 50 ° (2)
Here, 2W is the total angle of view of the light beam incident on the maximum image height position on the imaging plane.
The Abbe number to the d-line of the material forming the third lens is set to 30 or less, and the Abbe number to the d-line of the material forming the fourth lens to 30 or more. 3. The imaging lens according to any one of to 3.
The first lens according to any one of claims 1 to 4, wherein the first lens has a concave surface on the image side, the second lens has a convex surface on the object side, and the fifth lens has a convex surface on the object side. Imaging lens.
The imaging lens according to any one of claims 1 to 5, wherein all the lenses from the first lens to the fifth lens are formed of a glass material.
When the focal length of the first lens is f1, the focal length of the third lens is f3, and the focal length of the entire imaging lens system is f, the following conditional expressions (3) to (4) are satisfied: The imaging lens according to any one of claims 1 to 6.
-1.95 <f1 / f <-1.55 (3)
-1.3 <f3 / f <-0.9 (4)
From the object side, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, a third lens having negative refractive power, and a fourth lens having positive refractive power An imaging lens characterized by comprising a lens, a lens having a positive refractive power, and a fifth lens formed by cementing a lens having a negative refractive power, all the lenses being formed by spherical surfaces;
An imaging device for converting an optical image formed through the imaging lens into an electrical signal;
An imaging apparatus comprising:
A first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and a third lens having negative refractive power, which are provided in a vehicle and are arranged in order from the object side An imaging lens characterized by comprising a fourth lens having a power, a lens having a positive refractive power, and a fifth lens formed by cementing a lens having a negative refractive power, all the lenses being formed by spherical surfaces. An on-vehicle camera system comprising: an imaging device including: an imaging device configured to convert an optical image formed through the imaging lens into an electrical signal.
From the object side, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, a third lens having negative refractive power, and a fourth lens having positive refractive power What is claimed is: 1. An imaging lens comprising: a lens; a lens having a positive refractive power; and a fifth lens formed by cementing a lens having a negative refractive power, and satisfying the following conditional expressions (1) and (2).
dn / dt_n ≧ 3.0 (1)
L45 ≧ 0.2 (2)
However, dn / dt_n shows the average value of the temperature coefficient of the relative refractive index at the d-line of the lens having negative refractive power, and L45 shows the distance between the fourth lens and the fifth lens.
The imaging lens according to claim 10, which satisfies the following conditional expression (3).
2W ≧ 50 ° (3)
Here, 2W is the total angle of view of the light beam incident on the maximum image height position on the imaging plane.
12. The lens according to any one of claims 10 to 11, wherein the first lens has a concave surface on the image side, the second lens has a convex surface on the object side, and the fifth lens has a convex surface on the object side. Imaging lens.
The imaging lens according to any one of claims 10 to 12, wherein all the lenses from the first lens to the fifth lens are formed of a glass material.
The imaging lens according to any one of claims 10 to 13, wherein the following conditional expression (4) is satisfied.
dn / dt_p ≦ 4.0 (4)
However, dn / dt_p shows the average value of the temperature coefficient of the relative refractive index at the d-line of the lens having positive refractive power.
The imaging lens according to any one of claims 10 to 14, wherein one surface or both surfaces of the fourth lens has an aspheric shape.
When the focal length of the first lens is f1, the focal length of the third lens is f3, and the focal length of the entire imaging lens system is f, the following conditional expressions (5) to (6) are satisfied: The imaging lens according to any one of claims 1 to 6.
-1.8 <f1 / f <-1.3 (5)
-1.4 <f3 / f <-1.0 (6)
From the object side, in order from the object side, a first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, a third lens having negative refractive power, and a fourth lens having positive refractive power An imaging lens characterized by comprising a lens, a lens having a positive refractive power, and a fifth lens formed by cementing a lens having a negative refractive power, and satisfying the following conditional expressions (1) and (2): ,
An imaging device for converting an optical image formed through the imaging lens into an electrical signal;
An imaging apparatus comprising:
dn / dt_n ≧ 3.0 (1)
L45 ≧ 0.2 (2)
However, dn / dt_n shows the average value of the temperature coefficient of the relative refractive index at the d-line of the lens having negative refractive power, and L45 shows the distance between the fourth lens and the fifth lens.
A first lens having negative refractive power, a second lens having positive refractive power, an aperture stop, and a third lens having negative refractive power, which are provided in a vehicle and are arranged in order from the object side It consists of the 4th lens which has power, the lens which has positive refracting power, and the 5th lens which consists of junction of the lens which has negative refracting power, and is characterized by satisfying the following conditional expressions (1) and (2) An on-vehicle camera system comprising: an imaging device for imaging; and an imaging device for converting an optical image formed through the imaging lens into an electrical signal.
dn / dt_n ≧ 3.0 (1)
L45 ≧ 0.2 (2)
However, dn / dt_n shows the average value of the temperature coefficient of the relative refractive index at the d-line of the lens having negative refractive power, and L45 shows the distance between the fourth lens and the fifth lens.