JPWO2019107153A1 - Imaging lens and imaging device and in-vehicle camera system - Google Patents

Abstract

An image pickup lens having high optical performance can be obtained by appropriately setting the shape of the lens while being compact, lightweight and inexpensive. From the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, a third lens having a negative refractive power, and a fourth lens having a positive refractive power. It is composed of a lens, a fifth lens composed of a junction of a lens having a positive refractive power and a lens having a negative refractive power, and all the lenses are formed by a spherical surface.

Description

Cross-reference of related applications

This application claims the priority of Japanese Patent Application No. 2017-227714 (filed on November 28, 2017) and Japanese Patent Application No. 2017-228099 (filed on November 28, 2017). The entire disclosure of the application is incorporated here for reference.

The present invention relates to an image pickup lens, an image pickup device, and an in-vehicle camera system.

Imaging lenses used in surveillance cameras or in-vehicle cameras are required to be resistant to changes in the environment and to have good imaging performance over the entire screen. In addition, since the mounting space is often limited, it is required to be small and lightweight. For example, imaging lenses used in surveillance cameras or in-vehicle cameras are expected to be used in various regions from cold to tropical regions, and in-vehicle sensing cameras, which have become widespread in recent years, have a longer usage time than rear cameras. Therefore, there is a demand for an optical system that can be used in a wider temperature range. In addition, sensing applications for detecting objects have been added from conventional visual applications, and further improvement in performance is required. With the increase in the number of pixels of the image sensor, good optical performance is required over the entire screen to match it. Furthermore, since the mounting space is limited, it is required to be small and lightweight.

The following Patent Documents 1 and 2 have been proposed as single-focus imaging lenses that may be able to meet these demands.

Japanese Patent Application Laid-Open No. 2008-8960 JP 2013-47753

In recent years, in-vehicle cameras have been added to sensing applications for detecting objects from conventional visual applications, and further improvement in performance is required. Further, as the number of pixels of the image sensor is increased, good optical performance commensurate with it is required.

The present invention has been made in view of the above points, and an object of the present invention is to provide an image pickup lens having high optical performance while being compact, lightweight and inexpensive. Furthermore, an object of the present invention is to provide an image pickup lens, an image pickup device, and an in-vehicle camera system which are compact, lightweight, inexpensive, have optical performance, and have high weather resistance.

The imaging lenses that achieve the above objectives are, in order from the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, and a third lens having a negative refractive power. It is composed of a fourth lens having a positive refractive power, a fifth lens composed of a junction of a lens having a positive refractive power and a lens having a negative refractive power, and all the lenses are formed by a spherical surface. And.

Further, the image pickup apparatus that achieves the above object is, in order from the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, and a third lens having a negative refractive power. It is composed of a lens, a fourth lens having a positive refractive force, a fifth lens formed by joining a lens having a positive refractive force and a lens having a negative refractive force, and all the lenses are formed by a spherical surface. It is provided with an image pickup lens characterized by the above, and an image pickup element that converts an optical image formed through the image pickup lens into an electric signal.

Further, an in-vehicle camera system that achieves the above object is provided in the vehicle, and in order from the object side, a first lens having a negative refractive force, a second lens having a positive refractive force, an aperture aperture, and a negative lens. It is composed of a third lens having a refractive power, a fourth lens having a positive refractive power, a fifth lens consisting of a junction of a lens having a positive refractive power and a lens having a negative refractive power, and all the lenses are formed. The present invention includes an image pickup lens characterized by being formed of a spherical surface, and an image pickup device including an image pickup element that converts an optical image formed through the image pickup lens into an electric signal.

The imaging lenses that achieve the above objectives are, in order from the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, and a third lens having a 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 formed by joining a lens having a positive refractive power and a lens having a negative refractive power. When the average value of the temperature coefficient of the relative refractive index in the above is dn / dt_n and the distance between the fourth lens and the fifth lens is L45, the following conditional equations (1) and (2) are satisfied. Imaging lens.

dn / dt_n ≧ 3.0 ・ ・ ・ (1)
L45 ≧ 0.2 ・ ・ ・ (2)
Further, the imaging apparatus that achieves the above object is, in order from the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, and a third lens having a negative refractive power. The d-line of a lens having a negative power, which is composed of a lens, a fourth lens having a positive power, a fifth lens formed by joining a lens having a positive power and a lens having a negative power. When the average value of the temperature coefficient of the relative optical power in the above is dn / dt_n and the distance between the fourth lens and the fifth lens is L45, the following conditional equations (1) and (2) are satisfied. It includes an image pickup lens and an image pickup element that converts an optical image formed through the image pickup lens into an electric signal.

dn / dt_n ≧ 3.0 ・ ・ ・ (1)
L45 ≧ 0.2 ・ ・ ・ (2)
Further, an in-vehicle camera system that achieves the above object is provided in the vehicle, and in order from the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, and a negative are negative. It is composed of a third lens having a refractive power, a fourth lens having a positive refractive power, a fifth lens formed by joining a lens having a positive refractive power and a lens having a negative refractive power, and having a negative refractive power. When the average value of the temperature coefficient of the relative optical power in the d line of the lens having The present invention includes an image pickup lens comprising an image pickup lens for converting an optical image formed through the image pickup 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 that can be mounted in various places such as an automobile, having good imaging performance over the entire screen while ensuring a wide field of view, and having high optical performance. .. As a result, it is possible to realize a compact wide-angle image pickup lens that can be mounted on a surveillance camera or an in-vehicle camera, and an image pickup device using the same.

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

It is a figure which shows the basic structure of an image pickup lens. It is a figure which shows the structure of an image pickup lens. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is a figure which shows the structure of an image pickup lens. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is a figure which shows the relationship between the axial chromatic aberration and the difference of the Abbe number of the 5th lens. It is a figure which shows the structure of the image pickup apparatus. It is a figure which shows the arrangement in the vehicle of an in-vehicle camera system. It is a figure which shows the basic structure of an image pickup lens. It is a figure which shows the structure of an image pickup lens. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is a figure which shows the structure of an image pickup lens. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is a figure which shows the structure of an image pickup lens. It is an aberration diagram which shows spherical aberration. It is an aberration diagram which shows astigmatism. It is an aberration diagram which shows distortion. It is a figure which shows the relationship between the average value of the temperature coefficient of the relative refractive index in the d line of the lens which has a negative refractive power, and the focus shift amount at 105 degreeC. It is a figure which shows the relationship between the average value of the temperature coefficient of the relative refractive index in the d line of the lens which has a negative refractive power, and the focus shift amount at 105 degreeC. It is a figure which shows the relationship between the average value of the temperature coefficient of the relative refractive index in the d line of the lens which has a negative refractive power, and the focus shift amount at 105 degreeC. It is a figure which shows the structure of the image pickup apparatus. It is a figure which shows the arrangement in the vehicle of an in-vehicle camera system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The figures used in the following description are schematic, and the dimensional ratios and the like on the drawings do not always match the actual ones.

FIG. 1 shows the lens configurations of the embodiments in optical cross sections. 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 160/170, the flat plate filter, the flat plate 190, and the CCD (Charge Coupled) are arranged in this order from the object side. This is a five-element single-focus imaging lens 100 on which an imaging surface 200 serving as a light receiving surface of an imaging element 210 such as a Device) or a CMOS (Complementary Metal-Oxide Semiconductor device) is arranged.

The flat plate 180 may be a filter such as an infrared cut-coated filter or a low-pass filter. The flat plate 190 may be a cover glass of the image sensor 210.

In the imaging lens according to the present invention, the five lenses are, in order from the object side, the first lens 110 having a negative refractive power, the second lens 120 having a positive refractive power, the aperture aperture 130, and the negative refractive power. It is arranged like a third lens 140 having a positive refractive power, a fourth lens 150 having a positive refractive power, and a fifth lens 160/170 having a positive refractive power. Further, 1 (R1) to 12 (R11) shown in FIG. 1 are surface numbers of each constituent requirement.

The aperture diaphragm 130 is arranged between the second lens 120 and the third lens 140. Placing the aperture diaphragm 130 closer to the image than the fifth lenses 160 and 170 is not preferable because the lens system becomes larger, and placing it between the first lens 110 and the second lens 120 increases the back focus. On the other hand, it is disadvantageous and not preferable. Therefore, by arranging it between the second lens 120 and the third lens 140 described above, it is possible to satisfactorily correct various aberrations and make the lens system compact.

By joining the fifth lenses 160 and 170 with a lens having a positive refractive power and a lens having a negative refractive power, it becomes easy to correct axial chromatic aberration.

All lenses are formed by a spherical surface, which makes the lens easy to manufacture. Further, by not using an aspherical surface, deterioration of optical performance due to tolerance can be reduced.

In the imaging lens 100 in which the present invention is carried out, when the Abbe number of the lens 160 having a positive refractive power of the fifth lens is νa and the Abbe number of the lens 170 having a negative refractive power is νb, the following conditional equation (1) ) Satisfy.

30 ≧ νa−νb ≧ 17 ・ ・ ・ (1)
The conditional equation (1) correlates the difference between the Abbe numbers of the lens 160 having a positive refractive power and the lens 170 having a negative refractive power of the fifth lens. If the lower limit of the conditional expression (1) is exceeded, the difference in Abbe numbers is too small, and it becomes difficult to correct axial chromatic aberration due to negative refraction. On the other hand, if the upper limit is exceeded, axial chromatic aberration due to negative refraction is generated too much, resulting in excessive correction.

Further, the image pickup lens 100 is preferably configured so as to satisfy the conditional expression (2).

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

The conditional expression (2) is an expression relating to the angle of view of the entire imaging lens system. If the lower limit of the conditional expression (2) is exceeded, it becomes difficult to secure a shooting range that should be satisfied as an in-vehicle camera.

Further, in the image pickup lens 100, preferably, the Abbe number of the material constituting the third lens 140 with respect to the d-line is set to 30 or less, and the Abbe number of the material constituting the fourth lens 150 with respect to the d-line is set to 30 or more. The lens.

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

Further, it is preferable that the first lens 110 has a concave surface facing the image side, the second lens 120 has a convex surface facing the object side, and the fifth lens 160 has a convex surface facing the object side.

As a result, in the first lens 110, the light from the object side can be incident at a wide angle of view by turning the concave surface toward the image side. By directing the convex surface toward the object side in the second lens 120, the ghost generated on the image side surface of the first lens 110 is not focused. In the fifth lens 160, the incident light is imaged at a wide angle of view by directing the convex surface toward the object side.

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

As a result, changes in optical characteristics due to temperature changes can be suppressed.

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 equations (3) to (4) are satisfied. Will be done.

-1.95 <f1 / f <-1.55 ... (3)
-1.3 <f3 / f <-0.9 ... (4)
The conditional expression (3) associates the focal length of the first lens 110 with the focal length of the imaging lens 100. If the lower limit of the conditional expression (3) is exceeded, it becomes difficult to inject light from the object side at a wide angle of view, and if the upper limit is exceeded, the radius of curvature of the L1R2 surface becomes too small, making manufacturing difficult. It becomes. The conditional expression (4) associates the focal length of the third lens 140 with the focal length of the imaging lens 100. If the lower limit of the conditional expression (4) is exceeded, the power of the third lens 140 is too small and it becomes difficult to correct the axial chromatic aberration. If the upper limit is exceeded, the power of the third lens 140 is too large and the axial chromatic aberration is excessive. The correction of is excessive.

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

<Example 1>
The basic configuration of the image pickup lens 100A in the first embodiment is shown in FIG. 2, each numerical data (set value) is shown in Table 3, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. Is done.

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, and the third lens 140 arranged on the image side of the aperture diaphragm 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. D2, the distance between R3 surface 3 and R4 surface 4, which is the thickness of the second lens 120, is D3, the distance between R4 surface 4 of the second lens 120 and surface 5 of the aperture aperture 130 is D4, and the surface of the aperture aperture 130. The distance between 5 and R5 surface 6 of the 3rd lens 140 is D5, the distance between R5 surface 6 and R6 surface 7 which is the thickness of the 3rd lens 140 is D6, and the distance between R6 surface 7 and 4th lens 150 of the 3rd lens 140. The distance to the R7 surface 8 is D7, the distance between the R7 surface 8 and the R8 surface 9 which is the thickness of the fourth lens 150 is D8, and the distance between the R8 surface 9 of the fourth lens 150 and the R9 surface 10 of the fifth lens 160. The distance is D9, the distance between R9 surface 10 and R10 surface 11 which is the thickness of the fifth lens 160 is D10, the distance between R10 surface 11 and R11 surface 12 which is the thickness of the fifth lens 170 is D11, and the fifth lens 170. The distance between the R11 surface 12 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, and the distance between the surface 14 of the flat plate 180 and the surface 15 of the flat plate 190 is D14. The distance between the surface 15 and the surface 16 which is the thickness of the flat plate 190 is D15, and the distance between the surface 16 of the flat plate 190 and the imaging surface 200 is D16. In the following Examples 2 to 4 and Reference Examples 1 to 2, R1 surface 1 to surface 16 and D1 to D16 mean the same distance.

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

In Example 1, FIG. 3A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 3B shows astigmatism (solid line: 435.8 nm, 486.1 nm from the left). , 546.1nm, 587.6nm, 656.3nm sagittal rays, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm tangential rays from the left), Fig. 3C shows distortion (435.8nm, 486.1nm, 546.1nm, 587.6nm, and 656.3nm overlap), respectively. The vertical axis of FIGS. 3B and C represents the half angle of view ω, and in FIG. 3B, the solid line S indicates the value of the sagittal image plane and the broken line T indicates the value of the tangier image plane (FIGS. 5, 7, 9, and FIG. The same applies to 11). As can be seen from FIG. 3, according to the first embodiment, various aberrations of spherical surface, distortion, and non-points are satisfactorily corrected, and an image pickup lens 100A having excellent imaging performance can be obtained.

<Example 2>
The basic configuration of the imaging lens 100B according to the second embodiment is shown in FIG. 4, each numerical data (set value) is shown in Table 4, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. 5, respectively. Is done.

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, and the third lens 140 arranged on the image side of the aperture diaphragm 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 aperture corresponding to each surface number of the image pickup lens 100B in Example 2, the radius of curvature R, the interval D, the refractive index Nd, and the dispersion value νd of each lens.
Numerical Example 2

In FIG. 5, in Example 2, FIG. 5A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 5B shows astigmatism (solid line: 435.8 nm, 486.1 nm from the left). , 546.1nm, 587.6nm, 656.3nm sagittal rays, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm tangential rays from the left), Fig. 5C shows distortion (435.8nm, 486.1nm, 546.1nm, 587.6nm, and 656.3nm overlap), respectively. As can be seen from FIG. 5, according to the second embodiment, various aberrations of spherical surface, distortion, and non-points are satisfactorily corrected, and an image pickup lens 100B having excellent imaging performance can be obtained.

<Example 3>
Each numerical data (set value) in the third embodiment is shown in Table 5, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. 6, respectively.

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

In Example 3, FIG. 6A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 6B shows astigmatism (solid line: 435.8 nm, 486.1 from the left). Sagittal rays of nm, 546.1nm, 587.6nm, 656.3nm, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm astigmatism from the left, Fig. 6C shows distortion (435.8nm, 486.1nm) , 546.1nm, 587.6nm, 656.3nm overlap), respectively. As can be seen from FIG. 6, according to the third embodiment, various aberrations of spherical surface, distortion, and non-point are satisfactorily corrected, and an image pickup lens having excellent imaging performance can be obtained.

<Example 4>
Each numerical data (set value) in the fourth embodiment is shown in Table 6, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. 7, respectively.

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

In Example 4, FIG. 7A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 7B shows astigmatism (solid line: 435.8 nm, 486.1 from the left). Sagittal rays of nm, 546.1nm, 587.6nm, 656.3nm, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm astigmatism from the left, Fig. 7C shows distortion (435.8nm, 486.1nm) , 546.1nm, 587.6nm, 656.3nm overlap), respectively. As can be seen from FIG. 7, according to the fourth embodiment, various aberrations of spherical surface, distortion, and non-point are satisfactorily corrected, and an image pickup lens having excellent imaging performance can be obtained.

<Reference example 1>
Each numerical data (set value) in the fifth embodiment is shown in Table 7, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. 8, respectively.

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

In Reference Example 1, FIG. 8A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 8B shows astigmatism (solid line: 435.8 nm, 486.1 nm from the left). , 546.1nm, 587.6nm, 656.3nm sagittal rays, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm tangential rays from the left), Fig. 8C shows distortion (435.8nm, 486.1nm, 546.1nm, 587.6nm, and 656.3nm overlap), respectively.

<Reference example 2>
Each numerical data (set value) in the sixth embodiment is shown in Table 8, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. 9, respectively.

Table 8 shows the aperture corresponding to each surface number of the imaging lens in Reference Example 2, the radius of curvature R, the interval D, the refractive index Nd, and the dispersion value νd of each lens.
Numerical reference example 2

In Reference Example 2, FIG. 9A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 9B shows astigmatism (solid line: 435.8 nm, 486.1 nm from the left). , 546.1nm, 587.6nm, 656.3nm sagittal rays, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm tangential rays from the left), Fig. 9C shows distortion (435.8nm, 486.1nm, 546.1nm, 587.6nm, and 656.3nm overlap), respectively.

FIG. 10 shows the relationship between the axial chromatic aberration and the difference in the Abbe number of the fifth lens in Examples 1 to 4, Reference Examples 1 and 2. As can be seen from FIG. 10, the axial chromatic aberration can be suppressed to be small by setting the difference in Abbe number within a specific range. In order to satisfactorily correct the axial chromatic aberration, it is necessary to make it 0.05 or less, and the difference in Abbe number is 30 ≧ νa−νb ≧ 17.

Although the image pickup lens according to the present embodiment has been described above, the present invention is not limited to the image pickup lenses of these examples, and various modifications can be made without departing from the gist of the invention. For example, the specifications of the imaging lenses 100 of Examples 1 to 4 are examples, and various parameters can be changed within the scope of the present invention. Further, 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. Infrared coating may be applied to another lens surface or a filter such as a low-pass filter.

According to the present embodiment, it is possible to provide a wide-angle imaging lens that can be mounted in various places such as a surveillance camera or an in-vehicle camera, has good imaging performance over the entire screen while ensuring a wide field of view, and has high optical performance. ..

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

The subject image captured by the image pickup lens 100 and imaged on the light receiving surface of the image pickup element 210 is converted into an electric signal by the photoelectric conversion function of the image pickup element 210 and output from the image pickup element 210 as an image signal.

FIG. 12 is a diagram illustrating an example of an in-vehicle camera system in which an image pickup device 300 using an image pickup lens 100 according to an embodiment of the present invention is applied to an in-vehicle camera 410 mounted on a vehicle 400. The in-vehicle camera system includes an in-vehicle camera 410 and an image processing device 420. The in-vehicle camera 410 is attached to the inside or outside of the vehicle interior to capture a predetermined direction, but in the example of FIG. 12, it is fixed to the front part of the vehicle interior and around the front view of the vehicle 400. An image shall be taken.

The in-vehicle camera 410 outputs the acquired image to the image processing device 420 via the communication means in the vehicle 400. The image processing device 420 includes a processor dedicated to image processing such as an ASIC (Application Specific Integrated Circuit) for image processing and a DSP (Digital Signal Processor) and a memory for storing various information, and is output from the in-vehicle camera 410 and other in-vehicle cameras. White balance adjustment, exposure adjustment processing, color interpolation, brightness correction, gamma correction, and the like are performed on the image. Further, the image processing device 420 performs processing such as switching images, combining images from a plurality of in-vehicle cameras, cutting out a part of images, superimposing symbols, characters, expected locus lines, etc. on images, and displaying the images. An image signal conforming to the specifications of the device 430 is output. The in-vehicle camera 410 may have some or all the functions of the image processing device 420.

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

As described above, although the image pickup lens 100 is a wide-angle image pickup lens, the occurrence of distortion is reduced, and a subject image having high optical performance can be imaged on the light receiving surface of the image pickup element 210, and the visibility is excellent. The image signal of the image can be output. Further, even if the wavelength band is extended to near-infrared light for use in an environment with a low amount of light such as at night, axial chromatic aberration can be suppressed. Therefore, in particular, an in-vehicle image sensor 210 without an infrared cut filter is used. Suitable for camera 410. Further, since it can be made compact and lightweight, the mounting space can be made compact, and it is suitable for the image sensor 210 for various purposes.

Hereinafter, another embodiment of the present invention will be described with reference to the drawings. The figures used in the following description are schematic, and the dimensional ratios and the like on the drawings do not always match the actual ones.

FIG. 13 shows the lens configurations of the embodiments in optical cross sections. In this embodiment, the first lens 1110, the second lens 1120, the aperture diaphragm 1130, the third lens 1140, the fourth lens 1150, the fifth lens 1160/1170, the flat plate 1180, the flat plate 1190, and the CCD (Charge Coupled) are arranged in this order from the object side. This is a five-element single-focus imaging lens 1100 on which an imaging surface 1200 serving as a light receiving surface of an imaging element 1210 such as a Device) or a CMOS (Complementary Metal-Oxide Semiconductor device) is arranged.

In the imaging lens according to the present invention, the five lenses are, in order from the object side, the first lens 1110 having a negative refractive power, the second lens 1120 having a positive refractive power, the aperture aperture 1130, and the negative refractive power. The third lens 1140 has a positive refractive power, the fourth lens 1150 has a positive refractive power, and the fifth lens 1160/1170 has a positive refractive power. Further, 1 (R1) to 12 (R11) shown in FIG. 13 are surface numbers of each constituent requirement.

The aperture diaphragm 1130 is arranged between the second lens 1120 and the third lens 1140. Placing the aperture diaphragm 1130 on the image side of the fifth lens 1160 and 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. On the other hand, it is disadvantageous and not preferable. Therefore, by arranging the lens between the second lens 1120 and the third lens 1140 described above, it is possible to satisfactorily correct various aberrations and make the lens system compact.

By joining the fifth lens 1160 and 1170 with a lens having a positive refractive power and a lens having a negative refractive power, it becomes easy to correct axial chromatic aberration.

In the imaging lens 1100 in which the present invention is carried out, the average value of the temperature coefficient of the relative refractive index in the d line of the lens having a negative refractive power is dn / dt_n, and the distance between the fourth lens 1150 and the fifth lens 1160/1170. Is L45, it is configured to satisfy the following conditional equations (5) and (6).

dn / dt_n ≧ 3.0 ・ ・ ・ (5)
L45 ≧ 0.2 ・ ・ ・ (6)
The conditional equation (5) is an equation relating to the average value of the temperature coefficients of the relative refractive indexes on the d-line of the first lens 1110, the third lens 1130, and the fifth lens 1170 having a negative refractive power. At high temperatures, glass lenses usually change in the direction of increasing refractive power, but when the lower limit of conditional expression (5) is exceeded, the refractive power of lenses with negative refractive power does not change easily in the direction of increasing. The focus shifts to the object side. The conditional expression (6) is an expression relating to the distance between the fourth lens 1150 and the fifth lens 1160/1170. If the lower limit of the conditional expression (6) is exceeded, the general manufacturing tolerance of 20 μm occupies 10% or more of the design value, which makes manufacturing difficult.

Further, the image pickup lens 1100 is preferably configured so as to satisfy the conditional expression (7).

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

The conditional expression (7) is an expression relating to the angle of view of the image pickup lens 1100. If the lower limit of the conditional expression (7) is exceeded, it becomes difficult to secure a shooting range that should be satisfied as an in-vehicle sensing camera.

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

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

Further, it is preferable that all the lenses from the first lens 1110 to the fifth lens 1170 are made of a glass material.

As a result, it is possible to suppress a decrease in transmittance due to yellowing.

Further, the image pickup lens 1100 is preferably configured so as to satisfy the conditional expression (8).

dn / dt_p ≦ 4.0 ・ ・ ・ (8)
However, dn / dt_p indicates the average value of the temperature coefficient of the relative refractive index on the d line of the lens having a positive refractive power.

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

Further, it is preferable that the fourth lens 1150 has an aspherical shape on one side or both sides.

This facilitates aberration correction and makes it possible to obtain good resolution performance in spite of its small size.

Further, 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 equations (9) to (10) are satisfied. Will be done.

-1.8 <f1 / f <-1.3 ... (9)
-1.4 <f3 / f <-1.0 ... (10)
The conditional expression (9) associates the focal length of the first lens 1110 with the focal length of the imaging lens 1100. If the lower limit of the conditional expression (9) is exceeded, it becomes difficult to inject light from the object side at a wide angle of view, and if the upper limit is exceeded, the radius of curvature of the L1R2 surface becomes too small, making manufacturing difficult. It becomes. The conditional expression (10) associates the focal length of the third lens 1140 with the focal length of the imaging lens 1100. If the lower limit of the conditional expression (10) is exceeded, the power of the third lens 1140 is too small to correct the axial chromatic aberration, and if it exceeds the upper limit, the power of the third lens 1140 is too large to correct the axial chromatic aberration. The correction of is excessive.

In the shape of the aspherical lens of the lens described in the following numerical examples, the direction from the object side to the image plane side is positive, k is the conical coefficient, A is the fourth-order aspherical coefficient, and B is. Is expressed by the following equation, where C is the 6th-order aspherical coefficient, C is the 8th-order aspherical coefficient, and D is the 10th-order aspherical coefficient. h represents the height of the light ray, c represents the reciprocal of the radius of curvature of the center, and Z represents the depth from the tangent plane to the surface apex.

Examples 5 to 10 and Reference Examples 3 to 5 based on specific numerical values of the image pickup lens 100 are shown below. In the numerical examples of Examples 5 to 10 and Reference Examples 3 to 5, the focal length, F value, image height, and total lens length are as shown in Table 9 below. Similarly, in the numerical examples of Examples 5 to 10 and Reference Examples 3 to 5, the numerical data of the conditional expressions (5) to (10) have the values shown in Table 10 below.

<Example 5>
The basic configuration of the imaging lens 1100A according to the seventh embodiment is shown in FIG. 14, each numerical data (set value) is shown in Table 11, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. 15, respectively. Is done.

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 arranged on the image side of the aperture diaphragm 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. D2, the distance between R3 surface 3 and R4 surface 4 which is the thickness of the second lens 1120 is D3, the distance between R4 surface 4 of the second lens 1120 and surface 5 of the aperture aperture 1130 is D4, and the surface of the aperture aperture 1130. The distance between 5 and R5 surface 6 of the 3rd lens 1140 is D5, the distance between R5 surface 6 and R6 surface 7 which is the thickness of the 3rd lens 1140 is D6, and the distance between R6 surface 7 and 4th lens 1150 of the 3rd lens 1140. The distance to R7 surface 8 is D7, the distance between R7 surface 8 and R8 surface 9 which is the thickness of the 4th lens 1150 is D8, and the distance to R8 surface 9 of the 4th lens 1150 and R9 surface 10 of the 5th lens 1160. The distance is D9, the distance between R9 surface 10 and R10 surface 11 which is the thickness of the fifth lens 1160 is D10, the distance between R10 surface 11 and R11 surface 12 which is the thickness of the fifth lens 1170 is D11, and the fifth lens 1170. The distance between the R11 surface 12 and the surface 13 of the flat plate 1180 is D12, the distance between the surface 13 and the surface 14 having the thickness of the flat plate 1180 is D13, and the distance between the surface 14 of the flat plate 1180 and the surface 15 of the flat plate 1190 is D14. The distance between the surface 15 and the surface 16 which is the thickness of the flat plate 1190 is D15, and the distance between the surface 16 of the flat plate 1190 and the imaging surface 1200 is D16. In the following Examples 6 to 10 and Reference Examples 3 to 4, R1 planes 1 to 16 and D1 to D16 mean the same distances.

Table 11 shows the apertures corresponding to the surface numbers of the imaging lens 1100A in Example 5, the radius of curvature R (mm), the interval D (mm), the refractive index Nd, the dispersion value νd, and the relative refractive index on the d line of each lens. The temperature coefficient dn / dt and the linear expansion coefficient α of are shown. The surfaces marked with * in the surface numbers in Table 11 indicate that they have an aspherical shape. Table 12 shows the aspherical coefficients of the predetermined surface.
Numerical Example 5

In FIG. 15, in Example 5, FIG. 15A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 15B shows astigmatism (solid line: 435.8 nm, 486.1 nm from the left). , 546.1nm, 587.6nm, 656.3nm sagittal rays, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm tangential rays from the left), Fig. 15C shows distortion (435.8nm, 486.1nm, 546.1nm, 587.6nm, and 656.3nm overlap), respectively. The vertical axis of FIGS. 15B and C represents the half angle of view ω, in FIG. 15B, the solid line S indicates the value of the sagittal image plane, and the broken line T indicates the value of the tangier image plane (FIGS. 17, 19, 21, The same applies to 23). As can be seen from FIG. 15, according to the fifth embodiment, various aberrations of spherical surface, distortion, and non-points are satisfactorily corrected, and an imaging lens 1100A having excellent imaging performance can be 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 those in the fifth embodiment. Each numerical data (set value) is shown in Table 13.

Table 13 shows the apertures corresponding to the surface numbers of the imaging lenses in Example 6, the radius of curvature R (mm), the interval D (mm), the refractive index Nd, the dispersion value νd, and the relative refractive index in the d line of each lens. The temperature coefficient dn / dt and the linear expansion coefficient α are shown. The surfaces marked with * in the surface numbers in Table 13 indicate that they have an aspherical shape. Table 14 shows the aspherical coefficients of the predetermined surface.
Numerical Example 6

<Example 7>
The basic configuration of the imaging lens 1100B according to the ninth embodiment is shown in FIG. 16, each numerical data (set value) is shown in Table 15, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. Is done.

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 biconvex shape, and the third lens 1140 arranged on the image side of the aperture diaphragm 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 biconvex shape.

Table 15 shows the apertures corresponding to the surface numbers of the imaging lenses in Example 7, the radius of curvature R (mm), the interval D (mm), the refractive index Nd, the dispersion value νd, and the relative refractive index in the d line of each lens. The temperature coefficient dn / dt and the linear expansion coefficient α are shown. The surfaces marked with * in the surface numbers in Table 15 indicate that they have an aspherical shape. Table 16 shows the aspherical coefficients of the predetermined surface.
Numerical Example 7

In Example 7, FIG. 17A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 17B shows astigmatism (solid line: 435.8 nm, 486.1 from the left). Sagittal rays of nm, 546.1nm, 587.6nm, 656.3nm, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm astigmatism from the left, Fig. 17C shows distortion (435.8nm, 486.1nm) , 546.1nm, 587.6nm, 656.3nm overlap), respectively. As can be seen from FIG. 17, according to the seventh embodiment, various aberrations of spherical surface, distortion, and non-points are satisfactorily corrected, and an image pickup lens having excellent 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 those in the seventh embodiment. Each numerical data (set value) is shown in Table 17.

Table 17 shows the apertures corresponding to the surface numbers of the imaging lenses in Example 7, the radius of curvature R (mm), the interval D (mm), the refractive index Nd, the dispersion value νd, and the relative refractive index in the d line of each lens. The temperature coefficient dn / dt and the linear expansion coefficient α are shown. The surfaces marked with * in the surface numbers in Table 17 indicate that they have an aspherical shape. Table 18 shows the aspherical coefficients of the predetermined surface.
Numerical Example 8

<Example 9>
The basic configuration of the imaging lens 1100C according to the eleventh embodiment is shown in FIG. 18, each numerical data (set value) is shown in Table 19, and an aberration diagram showing spherical aberration, distortion, and astigmatism is shown in FIG. Is done.

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 biconvex shape, and the third lens 1140 arranged on the image side of the aperture diaphragm 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 biconvex shape.

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

In FIG. 19, in Example 9, FIG. 19A shows spherical aberration (435.8 nm, 486.1 nm, 546.1 nm, 587.6 nm, 656.3 nm from the left), and FIG. 19B shows astigmatism (solid line: 435.8 nm, 486.1 from the left). Sagittal rays of nm, 546.1nm, 587.6nm, 656.3nm, dotted lines: 435.8nm, 486.1nm, 546.1nm, 587.6nm, 656.3nm tangential rays from the left), Fig. 19C shows distortion (435.8nm, 486.1nm) , 546.1nm, 587.6nm, 656.3nm overlap), respectively. As can be seen from FIG. 19, according to the ninth embodiment, various aberrations of spherical surface, distortion, and non-point are satisfactorily corrected, 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 the twelfth embodiment are the same as those in the ninth embodiment. Each numerical data (set value) is shown in Table 21. Table 21 shows the aperture corresponding to each surface number of the imaging lens in Example 9, the radius of curvature R (mm), the interval D (mm), the refractive index Nd, the dispersion value νd, and the relative refractive index in the d line of each lens. The temperature coefficient dn / dt and the linear expansion coefficient α are shown. The surfaces marked with * in the surface numbers in Table 21 indicate that they have an aspherical shape. Table 22 shows the aspherical coefficients of the predetermined surface.
Numerical Example 10

<Reference example 3>
Each numerical data (set value) in the thirteenth embodiment is shown in Table 17.

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

<Reference example 4>
Each numerical data (set value) in the 14th embodiment is shown in Table 25.

Table 25 shows the apertures corresponding to the surface numbers of the imaging lenses in Reference Example 4, the radius of curvature R (mm), the interval D (mm), the refractive index Nd, the dispersion value νd, and the relative refractive index in the d line of each lens. The temperature coefficient dn / dt and the linear expansion coefficient α are shown. The surfaces marked with * in the surface numbers in Table 25 indicate that they have an aspherical shape. Table 26 shows the aspherical coefficients of the predetermined surface.
Numerical reference example 4

<Reference example 5>
Each numerical data (set value) in the 15th embodiment is shown in Table 27.

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

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

Although the image pickup lens according to the present embodiment has been described above, the present invention is not limited to the image pickup lenses of these examples, and various modifications can be made without departing from the gist of the invention. For example, the specifications of the image pickup lens 1100 of Examples 5 to 8 are examples, and various parameters can be changed within the scope of the present invention. Further, in the above embodiment, the cover glass (flat plate) 1190 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) 1190. Infrared coating may be applied to another lens surface or a filter such as a low-pass filter.

According to the present embodiment, it is possible to provide a wide-angle imaging lens that can be mounted in various places such as a surveillance camera or an in-vehicle camera, has good imaging performance over the entire screen while ensuring a wide field of view, and has high optical performance. ..

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

The subject image captured by the image pickup lens 1100 and imaged on the light receiving surface of the image pickup element 1210 is converted into an electric signal by the photoelectric conversion function of the image pickup element 1210 and output from the image pickup element 1210 as an image signal.

FIG. 24 is a diagram illustrating an example of an in-vehicle camera system in which an image pickup device 1300 using an image pickup lens 1100 according to an embodiment of the present invention is applied to an in-vehicle camera 1410 mounted on a vehicle 1400. The in-vehicle camera system includes an in-vehicle camera 1410 and an image processing device 1420. The in-vehicle camera 1410 can be attached to the inside or outside of the vehicle interior of the vehicle 1400 to take an image of a predetermined direction. However, in the example of FIG. 24, the in-vehicle camera 1410 is fixed to the front part of the vehicle interior and around the front view of the vehicle 1400. An image shall be taken.

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

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

As described above, although the image pickup lens 1100 is a wide-angle image pickup lens, it can reduce the occurrence of distortion and can form a subject image with high optical performance on the light receiving surface of the image pickup element 1210, and has excellent visibility. The image signal of the image can be output. Furthermore, even if the wavelength band is extended to near-infrared light for use in an environment with a low amount of light such as at night, axial chromatic aberration can be suppressed. Therefore, in particular, an in-vehicle image sensor 1210 using an image sensor 1210 without an infrared cut filter is used. Suitable for camera 1410. Further, since it can be made compact and lightweight, the mounting space can be made compact, and it is suitable for the image sensor 1210 for various purposes.

100, 100A-100B Imaging lens 110 1st lens 120 2nd lens 130 Aperture aperture 140 3rd lens 150 4th lens 160 5th lens 170 5th lens 180 Flat plate 190 Flat plate 200 Imaging surface 210 Imaging element 220 Housing 300 Imaging device 400 Vehicle 410 In-vehicle camera 420 Image processing device 430 Display device 1100, 1100A to 1100C Imaging lens 1110 1st lens 1120 2nd lens 1130 Aperture aperture 1140 3rd lens 1150 4th lens 1160 5th lens 1170 5th lens 1180 Flat plate 1190 Flat plate 1200 Imaging surface 1210 Imaging element 1220 Housing 1300 Imaging device 1400 Vehicle 1410 In-vehicle camera 1420 Image processing device 1430 Display device

Claims (18)

From the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, a third lens having a negative refractive power, and a fourth lens having a positive refractive power. An imaging lens comprising a lens, a fifth lens formed by joining a lens having a positive refractive power and a lens having a negative refractive power, and all lenses are formed of a spherical surface. The present invention is characterized in that the following conditional expression (1) is satisfied when the Abbe number of the lens having a positive refractive power of the fifth lens is νa and the Abbe number of the lens having a negative refractive power is νb. The imaging lens according to 1.
30 ≧ νa−νb ≧ 17 ・ ・ ・ (1) The imaging lens according to any one of claims 1 and 2, wherein the image pickup lens satisfies the following conditional expression (2).
2W ≧ 50 ° ・ ・ ・ (2)
However, 2W is the total angle of view of the light beam incident on the maximum image height position on the image plane. Claim 1 is characterized in that the Abbe number of the material constituting the third lens with respect to the d-line is set to 30 or less, and the Abbe number of the material constituting the fourth lens with respect to the d-line is set to 30 or more. The imaging lens according to any one of 3 to 3. The invention according to any one of claims 1 to 4, wherein the first lens has a concave surface facing the image side, the second lens has a convex surface facing the object side, and the fifth lens has a convex surface facing 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 made 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 equations (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, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, a third lens having a negative refractive power, and a fourth lens having a positive refractive power. An imaging lens composed of a lens, a fifth lens formed by joining a lens having a positive refractive power and a lens having a negative refractive power, and all lenses being formed by a spherical surface.
An image sensor that converts an optical image formed through the image pickup lens into an electrical signal,
An imaging device characterized by comprising. A first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, a third lens having a negative refractive power, and positive refraction, which are provided in a vehicle and have a negative refractive power in this order from the object side. An imaging lens composed of a fourth lens having a force, a fifth lens formed by joining a lens having a positive refractive force and a lens having a negative refractive force, and all lenses are formed by a spherical surface. An in-vehicle camera system including an imaging device that converts an optical image formed through the imaging lens into an electric signal. From the object side, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, a third lens having a negative refractive power, and a fourth lens having a positive refractive power. An imaging lens comprising a lens, a fifth lens formed by joining a lens having a positive refractive power and a lens having a negative refractive power, and satisfying the following conditional equations (1) and (2).
dn / dt_n ≧ 3.0 ・ ・ ・ (1)
L45 ≧ 0.2 ・ ・ ・ (2)
However, dn / dt_n indicates the average value of the temperature coefficient of the relative refractive index on the d line of the lens having a negative refractive power, and L45 indicates the distance between the fourth lens and the fifth lens. The imaging lens according to claim 10, wherein the imaging lens satisfies the following conditional expression (3).
2W ≧ 50 ° ・ ・ ・ (3)
However, 2W is the total angle of view of the light beam incident on the maximum image height position on the image plane. The method according to any one of claims 10 to 11, wherein the first lens has a concave surface facing the image side, the second lens has a convex surface facing the object side, and the fifth lens has a convex surface facing 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 made of a glass material. The imaging lens according to any one of claims 10 to 13, wherein the image pickup lens satisfies the following conditional expression (4).
dn / dt_p ≦ 4.0 ・ ・ ・ (4)
However, dn / dt_p indicates the average value of the temperature coefficient of the relative refractive index on the d line of the lens having a positive refractive power. The imaging lens according to any one of claims 10 to 14, wherein the fourth lens has an aspherical shape on one side or both sides. 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 equations (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, a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, a third lens having a negative refractive power, and a fourth lens having a positive refractive power. An image pickup lens composed of a lens, a fifth lens formed by joining a lens having a positive refractive power and a lens having a negative refractive power, and satisfying the following conditional equations (1) and (2). ,
An image sensor that converts an optical image formed through the image pickup lens into an electrical signal,
An imaging device characterized by comprising.
dn / dt_n ≧ 3.0 ・ ・ ・ (1)
L45 ≧ 0.2 ・ ・ ・ (2)
However, dn / dt_n indicates the average value of the temperature coefficient of the relative refractive index on the d line of the lens having a negative refractive power, and L45 indicates the distance between the fourth lens and the fifth lens. A first lens having a negative refractive power, a second lens having a positive refractive power, an aperture aperture, a third lens having a negative refractive power, and positive refraction, which are provided in a vehicle and have a negative refractive power in this order It is composed of a fourth lens having a force, a fifth lens formed by joining a lens having a positive refractive force and a lens having a negative refractive force, and is characterized by satisfying the following conditional equations (1) and (2). An in-vehicle camera system including an image pickup lens, and an image pickup element that converts an optical image formed through the image pickup lens into an electric signal.
dn / dt_n ≧ 3.0 ・ ・ ・ (1)
L45 ≧ 0.2 ・ ・ ・ (2)
However, dn / dt_n indicates the average value of the temperature coefficient of the relative refractive index on the d line of the lens having a negative refractive power, and L45 indicates the distance between the fourth lens and the fifth lens.

Images