CN109313323B - Image pickup optical system, lens member, and image pickup apparatus - Google Patents

Abstract

The imaging optical system includes, in order from an object side: a 1 st lens group (Gr1) substantially composed of a 1 st lens (L1) having a negative refractive power, a 2 nd lens (L2) having a negative refractive power, a 3 rd lens (L3) having a positive refractive power, and a 4 th lens (L4) having a positive refractive power; an aperture Stop (ST); and a 2 nd lens group (Gr2) substantially composed of a 5 th lens (L5) having a positive refractive power, a 6 th lens (L6) having a negative refractive power, and a 7 th lens (L7) having a positive refractive power, and the 4 th lens (L4) has a meniscus shape with a concave surface toward the object side.

Description

Image pickup optical system, lens member, and image pickup apparatus

Technical Field

The present invention relates to an imaging optical system, a lens unit, and an imaging device for use in, for example, a vehicle or a monitor.

Background

In recent years, there has been a demand for a compact, high-resolution, wide-angle, and high-F-number-light optical system that can be applied to sensing applications such as automatic monitoring, among imaging optical systems, particularly in an in-vehicle optical system. Patent document 1 discloses an optical system in which the number of lens blocks is 7 and the angle of view is about 180 °.

The optical system in patent document 1 has a size and a viewing angle suitable for vehicle mounting, but has insufficient optical performance such as a dark F-number of 2.8 and insufficient contrast around the screen due to chromatic aberration and coma.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-102291

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide an imaging optical system which is small, has an angle of view of 180 ° or more, is bright to the degree of F2, and is well corrected for aberrations.

Another object of the present invention is to provide a lens unit and an imaging device including the imaging optical system.

In order to achieve at least one of the above objects, an imaging optical system according to an aspect of the present invention includes, in order from an object side: a 1 st lens group substantially composed of a 1 st lens having a negative refractive power, a 2 nd lens having a negative refractive power, a 3 rd lens having a positive refractive power, and a 4 th lens having a positive refractive power; an aperture diaphragm; and a 2 nd lens group substantially composed of a 5 th lens having a positive refractive power, a 6 th lens having a negative refractive power, and a 7 th lens having a positive refractive power, the 4 th lens having a meniscus shape with a concave surface toward the object side.

Further, a lens member reflecting one aspect of the present invention includes the above-described imaging optical system and a lens barrel holding the imaging optical system.

An imaging apparatus reflecting an aspect of the present invention includes the imaging optical system and an imaging element that detects an image obtained from the imaging optical system.

Drawings

Fig. 1 is a diagram illustrating a lens unit and an imaging device including an imaging optical system according to an embodiment of the present invention.

Fig. 2A is a sectional view showing an imaging optical system and the like of example 1, and fig. 2B and 2C are aberration diagrams.

Fig. 3A is a sectional view showing an imaging optical system and the like of example 2, and fig. 3B and 3C are aberration diagrams.

Fig. 4A is a sectional view showing an imaging optical system and the like of example 3, and fig. 4B and 4C are aberration diagrams.

Fig. 5A is a sectional view showing an imaging optical system and the like of example 4, and fig. 5B and 5C are aberration diagrams.

Fig. 6A is a sectional view showing an imaging optical system and the like of example 5, and fig. 6B and 6C are aberration diagrams.

Fig. 7A is a sectional view showing an imaging optical system and the like of example 6, and fig. 7B and 7C are aberration diagrams.

Fig. 8A is a sectional view showing an imaging optical system and the like of example 7, and fig. 8B and 8C are aberration diagrams.

Fig. 9A is a sectional view showing an imaging optical system and the like of example 8, and fig. 9B and 9C are aberration diagrams.

Detailed Description

Fig. 1 is a sectional view showing an image pickup apparatus 100 as an embodiment of the present invention. The imaging device 100 includes: a camera module 30 for forming an image signal; and a processing unit 60 that functions as the imaging device 100 by operating the camera module 30.

The camera module 30 includes: a lens component 40 having the imaging optical system 10 built therein; and a sensor unit 50 for converting the subject image formed by the imaging optical system 10 into an image signal.

The lens unit 40 includes an imaging optical system 10 as a wide-angle optical system and a lens barrel 41 in which the imaging optical system 10 is incorporated. The imaging optical system 10 includes the 1 st lens L1 to the 7 th lens L7. The lens barrel 41 is formed of a resin, a metal, a material obtained by mixing glass fibers with a resin, or the like, and accommodates and holds a lens or the like therein. When the lens barrel 41 is formed of a material in which a glass fiber is mixed with a metal or a resin, the thermal expansion is less likely to occur than in the case of a resin, and the imaging optical system 10 can be stably fixed. The lens barrel 41 has an opening OP through which light from the object side is incident.

The imaging optical system 10 has a total angle of view of 180 ° or more. The 1 st lens L1 to the 7 th lens L7 constituting the imaging optical system 10 are directly or indirectly held on the inner surface side of the lens barrel 41 at the flange portions or the outer peripheral portions thereof, and are positioned with respect to the optical axis AX direction and the direction perpendicular to the optical axis AX.

The sensor unit 50 includes: an image pickup element (solid-state image pickup element) 51 that photoelectrically converts an object image formed by the image pickup optical system (wide-angle optical system) 10; and a substrate 52 supporting the imaging element 51. The image pickup device 51 is, for example, a CMOS type image sensor. The substrate 52 includes wiring, a peripheral circuit, and the like for operating the imaging element 51. The image pickup device 51 and the like are positioned and fixed with respect to the optical axis AX by a holder member, not shown. The holder member is fixed in a state of being positioned to be fitted to the lens barrel 41 of the lens member 40.

The image pickup device 51 includes a photoelectric conversion unit 51a provided with an image pickup surface I, and a signal processing circuit, not shown, is formed around the photoelectric conversion unit. The photoelectric conversion unit 51a has two-dimensionally arranged photoelectric conversion elements as pixels. The imaging element 51 is not limited to the CMOS type image sensor, and may be a component in which another imaging element such as a CCD is incorporated.

Further, a filter F or the like may be disposed between the lenses constituting the lens member 40 or between the lens member 40 and the sensor unit 50. In the example of fig. 1, the filter F is disposed between the 7 th lens L7 of the imaging optical system 10 and the imaging element 51. The filter F is a parallel flat plate assuming an optical low-pass filter, an IR cut filter, sheet glass of the image pickup device 51, and the like. The filter F may be disposed as an independent filter member, but may not be disposed independently and may provide its function to an arbitrary lens surface constituting the imaging optical system 10. For example, in the case of an infrared cut filter, an infrared cut coating layer may be added to the surface (optical surface) of 1 or more lenses.

The processing unit 60 includes an element driving unit 61, an input unit 62, a storage unit 63, a display unit 64, and a control unit 68. The device driving unit 61 outputs YUV and other digital pixel signals to an external circuit (specifically, a circuit attached to the image pickup device 51), or receives a voltage for driving the image pickup device 51 and a clock signal from the control unit 68 to operate the image pickup device 51. The input unit 62 is a unit that receives an operation by a user, an instruction from an external device, and the like, the storage unit 63 is a unit that stores information necessary for the operation of the image pickup apparatus 100, image data acquired by the camera module 30, and the like, and the display unit 64 is a unit that displays information to be presented by a user, a captured image, and the like. The control unit 68 collectively controls operations of the element driving unit 61, the input unit 62, the storage unit 63, and the like, and can perform various image processing on image data obtained by the camera module 30, for example.

Although detailed description is omitted, the specific function of the processing unit 60 is appropriately adjusted according to the application of the device in which the present image pickup apparatus 100 is incorporated. The imaging device 100 can be mounted on various devices for use such as an onboard camera and a monitoring camera.

The imaging optical system (wide-angle optical system) 10 and the like according to embodiment 1 will be described below with reference to fig. 1. The imaging optical system 10 illustrated in fig. 1 is configured substantially the same as the imaging optical system 10A of example 1 described later.

The illustrated imaging optical system (wide-angle optical system) 10 includes a 1 ST lens group Gr1, an aperture stop ST, and a 2 nd lens group Gr2 in this order from the object side. The 1 st lens group Gr1 is substantially composed of, in order from the object side, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. The 2 nd lens group Gr2 is substantially composed of, in order from the object side, a 5 th lens L5 having positive refractive power, a 6 th lens L6 having negative refractive power, and a 7 th lens L7 having positive refractive power. In the above, the 4 th lens L4 has a meniscus shape with the concave surface facing the object side.

In addition, the 6 th lens L6 has a biconcave shape. Accordingly, as compared with a case where only one surface has a negative refractive power like a negative meniscus lens, the negative refractive power is not excessively concentrated on one surface, astigmatism and chromatic aberration of magnification generated in the 6 th lens L6 can be suppressed, and sufficient negative refractive power can be obtained on both surfaces of the 6 th lens L6, so that spherical aberration, coma aberration, axial aberration, astigmatism and chromatic aberration of magnification generated in the positive 5 th lens L5 and the positive 7 th lens L7 before and after the positive 5 th lens L5 and the positive 7 th lens L7 can be corrected well.

The object-side surface of the 2 nd lens L2 has a concave shape toward the object side near the optical axis AX, and is located on the image side of the surface vertex at the effective diameter position. In this case, since the region near the optical axis AX is concave on the object-side surface of the 2 nd lens L2, the angle of incidence of the on-axis light beam on the lens surface can be reduced, and spherical aberration generated on the on-axis light beam can be suppressed. Further, since the object-side surface of the 2 nd lens L2 is formed to have a convex shape in a region outside the region near the optical axis AX by positioning the object-side surface to the image side of the surface vertex at the effective diameter position, the incident angle of the off-axis light incident on the region can be suppressed, and coma aberration and the like generated in the 2 nd lens L2 can be reduced.

The imaging optical system (wide-angle optical system) 10 satisfies the following conditional expression (1).

8≤f4/f≤15…(1)

Where the value f4 is the focal length of the 4 th lens L4, and the value f is the focal length of the entire system of lenses.

By setting the value f4/f of the conditional expression (1) to be equal to or greater than the lower limit value, the refractive power of the 4 th lens L4 is not excessively strong, and occurrence of spherical aberration, coma aberration, axial aberration, and error sensitivity can be suppressed. On the other hand, by setting the upper limit value of the conditional expression (1) or less, it is possible to prevent the imaging optical system 10 from being increased in size. That is, miniaturization can be maintained.

The imaging optical system 10 also satisfies the following conditional expression (2).

1.9≤d23/f≤3…(2)

Where the value d23 is the air interval on the optical axis AX of the 2 nd lens L2 and the 3 rd lens L3.

By setting the value d23/f of the conditional expression (2) to be equal to or greater than the lower limit value, the 2 nd lens L2 and the 3 rd lens L3 do not come too close to each other, and it is possible to prevent astigmatism, an amount of chromatic aberration of magnification, an increase in error sensitivity, and lens interference from each other due to mutual reinforcement of refractive powers. On the other hand, by setting the upper limit value of the conditional expression (2) to be equal to or less than the upper limit value, it is possible to prevent the entire length of the imaging optical system 10, the diameter of the front lens, and the like from increasing.

The imaging optical system 10 also satisfies the following conditional expression (3).

0.3≤d34/f≤0.8…(3)

Where the value d34 is the air interval on the optical axis AX of the 3 rd lens L3 and the 4 th lens L4.

By making the value d34/f of the conditional expression (3) the lower limit value or more, the 3 rd lens L3 and the 4 th lens L4 do not come too close, and it is possible to prevent the refractive powers from reinforcing each other and the amount of occurrence of spherical aberration, coma aberration, axial chromatic aberration, error sensitivity from becoming large, and prevent the lenses from interfering with each other. On the other hand, by setting the upper limit value of conditional expression (3) or less, it is possible to prevent the entire length of the imaging optical system 10, the diameter of the front lens, and the like from increasing in size.

The imaging optical system 10 also satisfies the following conditional expression (4).

0.2≤d67/f≤0.4…(4)

Where the value d67 is the air interval on the optical axis AX of the 6 th lens L6 and the 7 th lens L7.

By setting the value d67/f of the conditional expression (4) to be equal to or greater than the lower limit value, the 6 th lens L6 and the 7 th lens L7 do not come too close to each other, and it is possible to prevent astigmatism, an amount of chromatic aberration of magnification, an increase in error sensitivity, and lens interference from each other due to mutual reinforcement of refractive powers. On the other hand, by setting the upper limit value of conditional expression (4) or less, it is possible to prevent the entire length of the imaging optical system 10, the diameter of the front lens, and the like from increasing in size.

The imaging optical system 10 also satisfies the following conditional expression (5).

0.5≤f1/f2≤5…(5)

Where the value f1 is the focal length of the 1 st lens L1, and the value f2 is the focal length of the 2 nd lens L2.

By setting the value f1/f2 of the conditional expression (5) to be equal to or greater than the lower limit value, the refractive power of the 1 st lens L1 is not excessively strong with respect to the refractive power of the 2 nd lens L2, and the burden on the 1 st lens L1 is reduced, whereby astigmatism and chromatic aberration of magnification generated in the 1 st lens L1 can be reduced, and the error sensitivity of the 1 st lens L1 can be suppressed. On the other hand, by setting the upper limit value of the conditional expression (5) or less, the refractive power of the 2 nd lens L2 is not excessively strong with respect to the refractive power of the 1 st lens L1, and the burden on the 2 nd lens L2 is reduced, whereby astigmatism and chromatic aberration of magnification generated in the 2 nd lens L2 can be reduced, and the error sensitivity of the 2 nd lens L2 can be suppressed.

The imaging optical system 10 also satisfies the following conditional expression (6).

-12≤(r4i+r4o)/(r4i-r4o)<-1…(6)

Where the value r4i is the radius of curvature of the image-side surface of the 4 th lens L4, and the value r4o is the radius of curvature of the object-side surface of the 4 th lens L4.

By setting the value (r4i + r4o)/(r4i-r4o) of conditional expression (6) to be equal to or greater than the lower limit value, the front principal point position of the 4 th lens L4 is not too close to the 3 rd lens L3 side, the refractive power of the 4 th lens L4 is not excessively enhanced, and the combined refractive power of the 3 rd lens L3 and the 4 th lens L4 can be maintained strongly, so that the occurrence of aberration in the 4 th lens L4, error sensitivity, and downsizing of the imaging optical system 10 can be achieved. On the other hand, by falling below the upper limit of conditional expression (6), the curvature of the object-side surface of the 4 th lens L4 is not excessively increased, and performance degradation due to spherical aberration, coma aberration, and misalignment error that occur on this surface can be suppressed.

The imaging optical system 10 also satisfies the following conditional expression (7).

-12≤(r4i+r4o)/(r4i-r4o)≤-1.5…(7)

By satisfying the range of conditional expression (7), the effect of suppressing performance deterioration due to spherical aberration, coma aberration, and the like generated on the object-side surface of the 4 th lens L4 and misalignment error is further improved.

The imaging optical system 10 also satisfies the following conditional expression (8).

2≤f7/f≤4…(8)

Wherein the value f7 is the focal length of the 7 th lens L7.

By setting the value f7/f of the conditional expression (8) to be equal to or greater than the lower limit value, the refractive power of the 7 th lens L7 is not excessively strong, and performance variation due to chromatic aberration of magnification and decentering error occurring in the 7 th lens L7 can be suppressed. On the other hand, by setting the upper limit value of the conditional expression (8) or less, the refractive power of the 7 th lens L7 is not excessively weak, and the light incident angle to the image pickup element can be suppressed while maintaining the miniaturization of the image pickup optical system 10.

The imaging optical system 10 also satisfies the following conditional expression (9).

-6≤f6/f≤-2…(9)

Wherein the value f6 is the focal length of the 6 th lens L6.

By setting the value f6/f of the conditional expression (9) to be equal to or greater than the lower limit value, the refractive power of the 6 th lens L6 is not excessively weak, and the refractive powers sufficient to favorably correct spherical aberration, coma aberration, chromatic aberration on axis, astigmatism, and chromatic aberration of magnification generated in the positive 5 th lens L5 and the positive 7 th lens L7 before and after the positive 5 th lens L5 and the positive 7 th lens L7 are obtained. In addition, the miniaturization of the imaging optical system 10 can be maintained. On the other hand, by setting the upper limit value of the conditional expression (9) or less, the refractive power of the 6 th lens L6 is not excessively strong, and performance variations due to astigmatism, chromatic aberration of magnification, and decentering error generated in the 6 th lens L6 can be suppressed.

In addition, 3 lenses out of the 4 lenses of the 1 st lens group Gr1 are formed of plastic (or resin lenses). In the example of fig. 1, the 2 nd lens L2 to the 4 th lens L4 are plastic lenses. In addition, the 2 nd lens group Gr2 has 1 block each of a lens having a positive refractive power formed of plastic (or a resin lens) and a lens having a negative refractive power formed of plastic (or a resin lens). In the example of fig. 1, the 6 th lens L6 and the 7 th lens L7 are plastic lenses. In this case, the imaging optical system 10 also satisfies the following conditional expression (10).

-0.32≤f×Σ(1/fplk)≤0.32…(10)

Where the value fplk is the focal length of the k-th (k is a natural number) plastic lens from the object side.

In the 1 st lens group Gr1, the imaging optical system 10 can be reduced in weight by using plastic lenses as the 3 lenses. Further, by adding an aspherical surface by injection molding or the like, the degree of freedom of shape can be increased compared with that of a spherical surface, and spherical aberration, coma aberration, and the like can be corrected well. Further, a degree of freedom sufficient to cancel out the focus movement and the aberration variation at the time of temperature change can be obtained. Further, by using a plastic lens also for the 2 nd lens group Gr2, it is possible to secure optical performance by an aspherical surface with reduced weight, and it is possible to obtain sufficient freedom to cancel out the focus shift and aberration variation during temperature change, as in the 1 st lens group Gr 1. The conditional expression (10) is an expression that sums up the power (refractive power) of the plastic lens in the imaging optical system 10 and multiplies the focal length of the entire system of the imaging optical system 10. In the case of using a plastic lens, if the refractive power of the plastic lens is not appropriately set, the amount of focus movement and the amount of change in aberration at the time of temperature change become large, the imaging position greatly changes, or the performance greatly deteriorates. Therefore, in order to suppress the focal point shift and aberration variation due to temperature change, it is preferable that the combined powers of the positive and negative plastic lenses be mutually cancelled and the difference be reduced. By setting the value f × Σ (1/fplk) of the conditional expression (10) to the upper limit or less, it is possible to suppress an increase in the back focal length (back focus) due to excessive positive synthetic light focus when the temperature is changed to the high temperature side. Further, by setting the upper limit value of conditional expression (10) or less, it is possible to suppress a decrease in the back focal length due to an excessive positive composite light focus when the temperature is changed to the low temperature side. On the other hand, by setting the lower limit value of conditional expression (10) or more, it is possible to suppress a decrease in the back focal length due to excessive negative combined power when the temperature is changed to the high temperature side. Further, by setting the lower limit value of conditional expression (10) or more, it is possible to suppress an increase in the back focal length due to excessive negative combined power when the temperature is changed to the low temperature side.

The imaging optical system 10 may further include other optical elements (e.g., lenses, filter members, etc.) having substantially no optical power.

In the imaging optical system 10 and the like described above, in regard to the lens structure of the 1 ST lens group Gr1 which is the object side group with respect to the aperture stop ST being negative, positive, negative, and positive, the 1 ST lens L1 and the 2 nd lens L2 are negative, and therefore the entrance pupil can be disposed on the object side, and therefore a wide angle is achieved and the front lens is small in diameter, and the back focal length can be secured even if the focal length is short, and the installation space for filters and the like can be secured. By setting 2 negative lenses as compared with 1 negative lens, the refractive power can be divided, and excellent performance securing and error sensitivity suppression can be achieved. Further, by setting the 3 rd lens L3 and the 4 th lens L4 to positive, it is possible to cancel aberration when the 1 st lens L1 and the 2 nd lens L2 are negative. By setting 2 positive lenses, the refractive power can be divided to ensure good performance and suppress error sensitivity, as compared with 1 positive lens. By setting the lens configuration of the object side group to negative positive compared to the aperture stop ST in this way, a wide angle is achieved and the diameter of the front lens is small, so that the aberration correction in the object side group compared to the aperture stop ST can be performed satisfactorily while securing the back focal length. Further, by setting the lens configuration of the 2 nd lens group Gr2, which is an image side group with respect to the aperture stop ST, to a so-called triple (triplet) configuration in which the positive and negative are positive, it is possible to perform favorable aberration correction. By providing the aperture stop ST between the 4 th lens L4 and the 5 th lens L5 in this way, it is possible to suppress each aberration such as spherical aberration, coma aberration, astigmatism, and chromatic aberration to be smaller in the 1 ST lens group Gr1 on the object side and the 2 nd lens group Gr2 on the image side than the aperture stop ST, and it is possible to obtain excellent optical performance in the entire optical system. Further, since the 4 th lens L4 immediately before the aperture stop ST has a concave surface facing the object side, the front principal point can be disposed on the image side, and the principal point interval with the 3 rd lens L3 can be widened. As a result, the refractive power of the 4 th lens L4 can be reduced and the combined refractive power with the 3 rd lens L3 can be enhanced, so that the 1 st lens group Gr1 can be miniaturized while suppressing the occurrence of aberrations in the 4 th lens L4, and the entire optical system can be miniaturized as well.

The lens unit 40 and the imaging device 10 incorporating the above imaging optical system 10 are small and have an angle of view of 180 ° or more, and can perform imaging in a state where light is emitted to the degree of F2 and aberrations are well corrected.

[ example ]

Hereinafter, embodiments of the imaging optical system and the like of the present invention are described. The symbols used in the embodiments are as follows.

f: focal length of whole system of image pickup optical system

Fno: f number

w: half angle of view

ymax: maximum image height

TL: overall lens length (optical overall length) (distance on optical axis from lens surface closest to object side to image pickup surface)

BF: back focal length

PD Δ + 100: amount of focus shift due to temperature change of plastic lens at room temperature (20 ℃) to 100 ℃ and high temperature

PD delta-65: amount of focus shift due to temperature change of plastic lens at room temperature (20 ℃) to 65 ℃ and low temperature

R: radius of curvature

D: spacing on the shaft

nd: refractive index of lens material for d-line

vd: abbe number of lens material

In each of the embodiments, a surface having an aspherical shape whose origin is the vertex of the surface and whose height in the optical axis direction is h, and which is perpendicular to the optical axis, is represented by "expression 1" below.

[ formula 1]

Wherein the content of the first and second substances,

ai: aspheric coefficient of order i

R: reference radius of curvature

K: constant of cone

(example 1)

The overall specifications of the imaging optical system of example 1 are as follows.

f：0.80(mm)

Fno：2.00

w：100.0(°)

ymax：1.78(mm)

TL：16.72(mm)

BF：1.76(mm)

PDΔ+100：0.010(mm)

PDΔ-65：-0.007(mm)

Data of the lens surface of the imaging optical system of example 1 is shown in table 1 below. In table 1 and the like below, the surface number is denoted by "surf.n", the aperture stop is denoted by "ST", and infinity is denoted by "INF". Further, "image (image)" indicates an imaging surface I of the imaging element (or an imaging surface of the imaging optical system).

[ Table 1]

Image of a person

Practice ofThe aspherical surface coefficients of the lens surface of example 1 are shown in table 2 below. Further, a power multiplier of 10 (e.g., 2.5 × 10) is expressed using E (e.g., 2.5E-02) after that (including lens data of the table)^-02)。

[ Table 2 ]

No. 3 surface

K＝-25.077，A3＝4.1509E-04，A4＝2.6686E-02，A5＝-3.5274E-06，

A6＝-4.1268E-03，A7＝-1.4243E-06，A8＝2.3534E-04，

A9＝-1.5344E-09，

A10＝-3.0521E-06，A11＝3.8578E-09，A12＝-8.8504E-08

No. 4 surface

K＝-0.811，A3＝-3.1773E-03，A4＝2.9340E-02，A5＝3.0006E-04，

A6＝1.0939E-02，A7＝7.0688E-05，A8＝-1.7602E-03，

A9＝1.3531E-07，

A10＝-7.6839E-04，A11＝-2.3277E-06，A12＝1.3366E-04

The 5 th plane

K＝-37.166，A3＝0.0000E+00，A4＝2.4528E-02，A5＝0.0000E+00，

A6＝3.6392E-03，A7＝0.0000E+00，A8＝-7.2690E-04，

A9＝0.0000E+00，

A10＝-1.8210E-05，A11＝0.0000E+00，A12＝0.0000E+00

The 6 th plane

K＝23.563，A3＝0.0000E+00，A4＝1.0997E-03，A5＝0.0000E+00，

A6＝1.4216E-02，A7＝0.0000E+00，A8＝-5.4242E-03，

A9＝0.0000E+00，

A10＝7.1859E-04，A11＝0.0000E+00，A12＝0.0000E+00

The 7 th plane

K＝-0.018，A3＝0.0000E+00，A4＝-1.3978E-02，A5＝0.0000E+00，

A6＝3.5903E-03，A7＝0.0000E+00，A8＝2.5845E-03，

A9＝0.0000E+00，

A10＝-4.8319E-04，A11＝0.0000E+00，A12＝0.0000E+00

The 8 th plane

K＝-0.223，A3＝0.0000E+00，A4＝1.5099E-02，A5＝0.0000E+00，

A6＝2.9600E-03，A7＝0.0000E+00，A8＝8.3464E-04，

A9＝0.0000E+00，

A10＝5.9837E-06，A11＝0.0000E+00，A12＝0.0000E+00

The 12 th surface

K＝3.265，A3＝-5.1410E-03，A4＝-6.7048E-02，A5＝-4.2070E-04，

A6＝9.0069E-02，A7＝-3.1044E-05，A8＝-1.4354E-02，

A9＝3.2311E-04，

A10＝-2.0751E-02，A11＝-3.8932E-05，A12＝1.2127E-02

The 13 th side

K＝-25.945，A3＝3.9543E-03，A4＝-8.8412E-02，A5＝-3.9549E-04，

A6＝5.0067E-02，A7＝-1.6999E-04，A8＝-6.4724E-03，

A9＝-5.7314E-05，

A10＝-5.5126E-03，A11＝5.4156E-05，A12＝1.4799E-03

The 14 th side

K＝0.097，A3＝0.0000E+00，A4＝-3.8507E-02，A5＝0.0000E+00，

A6＝1.3087E-02，A7＝0.0000E+00，A8＝-1.4666E-03，

A9＝0.0000E+00，

A10＝-5.0820E-04，A11＝0.0000E+00，A12＝-2.8403E-04

The 15 th surface

K＝-0.007，A3＝0.0000E+00，A4＝1.1312E-01，A5＝0.0000E+00，

A6＝-8.0008E-03，A7＝0.0000E+00，A8＝-4.5930E-03，

A9＝0.0000E+00，

A10＝1.2483E-03，A11＝0.0000E+00，A12＝-1.7207E-04

Fig. 2A is a sectional view of the imaging optical system 10A and the like of embodiment 1. The imaging optical system 10A includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10A includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51. The filter F is a parallel flat plate assuming an optical low-pass filter, an IR cut filter, sheet glass of the image pickup device 51, and the like. Symbol I denotes an image pickup surface which is a projection surface of the image pickup device 51. Note that the same applies to the symbol F, I in the following embodiments.

Fig. 2B and 2C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10A of example 1.

(example 2)

The overall specifications of the imaging optical system of example 2 are as follows.

f：0.79(mm)

Fno：2.00

w：109.0(°)

ymax：1.93(mm)

TL：17.58(mm)

BF：1.69(mm)

PDΔ+100：0.010(mm)

PDΔ-65：-0.007(mm)

Data of the lens surface of the imaging optical system of example 2 is shown in table 3 below.

[ Table 3 ]

Image of a person

The aspherical surface coefficients of the lens surface of example 2 are shown in table 4 below.

[ Table 4 ]

No. 3 surface

K＝-19.437，A3＝4.9863E-03，A4＝2.5428E-02，A5＝8.9511E-05，

A6＝-4.0374E-03，A7＝2.7811E-05，A8＝2.3840E-04，

A9＝-2.1963E-06，

A10＝-4.3776E-06，A11＝-3.6092E-07，A12＝5.9175E-08

No. 4 surface

K＝-0.382，A3＝-8.8600E-03，A4＝4.0427E-02，A5＝-7.0662E-03，

A6＝1.0877E-02，A7＝8.5756E-04，A8＝-1.4503E-03，

A9＝3.5320E-05，

A10＝-7.7782E-04，A11＝-1.3482E-05，A12＝1.1987E-04

The 5 th plane

K＝-47.864，A3＝0.0000E+00，A4＝1.5994E-02，A5＝0.0000E+00，

A6＝4.5968E-03，A7＝0.0000E+00，A8＝-6.4438E-04，

A9＝0.0000E+00，

A10＝-6.4480E-05，A11＝0.0000E+00，A12＝0.0000E+00

The 6 th plane

K＝8.693，A3＝0.0000E+00，A4＝8.0564E-03，A5＝0.0000E+00，

A6＝1.3186E-02，A7＝0.0000E+00，A8＝-4.6153E-03，

A9＝0.0000E+00，

A10＝5.4267E-04，A11＝0.0000E+00，A12＝0.0000E+00

The 7 th plane

K＝0.453，A3＝0.0000E+00，A4＝1.1615E-02，A5＝0.0000E+00，

A6＝-2.2558E-03，A7＝0.0000E+00，A8＝4.8023E-04，

A9＝0.0000E+00，

A10＝6.6170E-05，A11＝0.0000E+00，A12＝0.0000E+00

The 8 th plane

K＝-0.631，A3＝0.0000E+00，A4＝1.2246E-02，A5＝0.0000E+00，

A6＝-7.4430E-04，A7＝0.0000E+00，A8＝6.3921E-04，

A9＝0.0000E+00，

A10＝-8.6881E-05，A11＝0.0000E+00，A12＝0.0000E+00

The 12 th surface

K＝-3.041，A3＝-2.0645E-02，A4＝-5.2684E-02，A5＝-2.7546E-02，

A6＝9.9184E-02，A7＝-1.8769E-02，A8＝-3.8630E-02，

A9＝-1.4754E-02，

A10＝-2.0615E-02，A11＝6.1857E-02，A12＝-2.3738E-02

The 13 th side

K＝-45.765，A3＝5.6264E-02，A4＝-4.2659E-02，A5＝-4.9907E-03，

A6＝2.6031E-02，A7＝-1.0363E-02，A8＝-2.6244E-03，

A9＝2.2607E-03，

A10＝-2.6797E-03，A11＝1.9979E-04，A12＝7.6732E-04

The 14 th side

K＝-0.903，A3＝0.0000E+00，A4＝-4.9819E-02，A5＝0.0000E+00，

A6＝2.2349E-02，A7＝0.0000E+00，A8＝-2.8134E-03，

A9＝0.0000E+00，

A10＝-2.8972E-04，A11＝0.0000E+00，A12＝1.0945E-04

The 15 th surface

K＝0.108，A3＝0.0000E+00，A4＝5.2170E-02，A5＝0.0000E+00，

A6＝-9.2593E-03，A7＝0.0000E+00，A8＝-1.6750E-04，

A9＝0.0000E+00，

A10＝2.0133E-03，A11＝0.0000E+00，A12＝-3.0057E-04

Fig. 3A is a sectional view of the imaging optical system 10B and the like of embodiment 2. The imaging optical system 10B includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10B includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51.

Fig. 3B and 3C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10B of example 2.

(example 3)

The overall specifications of the imaging optical system of example 3 are as follows.

f：0.80(mm)

Fno：2.00

w：109.0(°)

ymax：1.88(mm)

TL：18.38(mm)

BF：1.76(mm)

PDΔ+100：0.012(mm)

PDΔ-65：-0.008(mm)

Data of the lens surface of the imaging optical system of example 3 is shown in table 5 below. [ Table 5 ]

Image of a person

The aspherical surface coefficients of the lens surface of example 3 are shown in table 6 below.

[ Table 6 ]

No. 3 surface

K＝-43.995，A4＝2.7253E-02，A6＝-4.0502E-03，A8＝2.2958E-04，A10＝-4.1245E-06，A12＝-2.8666E-08，A14＝0.0000E+00

No. 4 surface

K＝-0.514，A4＝3.4588E-02，A6＝1.0951E-02，A8＝-2.0186E-03，

A10＝-8.0314E-04，A12＝1.3334E-04，A14＝0.0000E+00

The 5 th plane

K＝-50.000，A4＝1.6824E-02，A6＝4.4598E-03，A8＝-4.0892E-04，

A10＝-1.0623E-04，A12＝0.0000E+00，A14＝0.0000E+00

The 6 th plane

K＝13.039，A4＝-2.3680E-03，A6＝1.4067E-02，A8＝-4.3421E-03，

A10＝5.2746E-04，A12＝0.0000E+00，A14＝0.0000E+00

The 7 th plane

K＝-1.290，A4＝-1.4352E-02，A6＝2.9914E-03，A8＝-5.5569E-05，

A10＝8.8188E-05，A12＝0.0000E+00，A14＝0.0000E+00

The 8 th plane

K＝-0.447，A4＝1.5161E-02，A6＝-6.6790E-04，A8＝1.6586E-03，

A10＝-4.9605E-04，A12＝0.0000E+00，A14＝0.0000E+00

The 12 th surface

K＝2.102，A4＝-3.2293E-02，A6＝5.7594E-02，A8＝-1.7848E-02，

A10＝-4.3111E-03，A12＝5.8077E-03，A14＝0.0000E+00

The 13 th side

K＝-5.879，A4＝-7.9747E-02，A6＝4.7202E-02，A8＝-8.1966E-03，

A10＝-5.7734E-03，A12＝2.1106E-03，A14＝0.0000E+00

The 14 th side

K＝0.311，A4＝-3.7298E-02，A6＝1.5815E-02，A8＝-5.6439E-04，

A10＝-9.0989E-04，A12＝-2.5118E-04，A14＝2.0159E-05

The 15 th surface

K＝0.307，A4＝7.1796E-02，A6＝1.1905E-04，A8＝2.4355E-04，

A10＝1.2749E-03，A12＝-8.1303E-04，A14＝7.4716E-05

Fig. 4A is a sectional view of an imaging optical system 10C and the like of embodiment 3. The imaging optical system 10C includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10C includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51.

Fig. 4B and 4C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10C according to example 3.

(example 4)

The overall specifications of the imaging optical system of example 4 are as follows.

f：0.89(mm)

Fno：2.00

w：109.0(°)

ymax：1.91(mm)

TL：18.59(mm)

BF：1.90(mm)

PDΔ+100：0.009(mm)

PDΔ-65：-0.010(mm)

Data of the lens surface of the imaging optical system of example 4 is shown in table 7 below.

[ Table 7 ]

Image of a person

The aspherical surface coefficients of the lens surface of example 4 are shown in table 8 below.

[ Table 8 ]

No. 3 surface

K＝-49.998，A3＝-1.0581E-03，A4＝2.7633E-02，A5＝1.8548E-04，

A6＝-3.9424E-03，A7＝6.4290E-06，A8＝2.2756E-04，

A9＝-1.0998E-06，

A10＝-5.1477E-06，A11＝-4.0259E-08，A12＝3.1999E-08，

A13＝0.0000E+00，

A14＝0.0000E+00

No. 4 surface

K＝-0.559，A3＝-1.6913E-02，A4＝3.8109E-02，A5＝2.3290E-04，

A6＝1.0715E-02，A7＝-1.7913E-04，A8＝-1.8609E-03，

A9＝3.5529E-05，

A10＝-7.3099E-04，A11＝7.4857E-06，A12＝1.1418E-04，

A13＝0.0000E+00，

A14＝0.0000E+00

The 5 th plane

K＝-35.725，A3＝0.0000E+00，A4＝1.3648E-02，A5＝0.0000E+00，

A6＝4.3986E-03，A7＝0.0000E+00，A8＝-5.5820E-04，

A9＝0.0000E+00，

A10＝-8.4976E-05，A11＝0.0000E+00，A12＝-7.5787E-07，

A13＝0.0000E+00，

A14＝0.0000E+00

The 6 th plane

K＝13.667，A3＝0.0000E+00，A4＝1.0876E-04，A5＝0.0000E+00，

A6＝1.4886E-02，A7＝0.0000E+00，A8＝-4.3582E-03，

A9＝0.0000E+00，

A10＝5.2028E-04，A11＝0.0000E+00，A12＝-1.7726E-06，

A13＝0.0000E+00，

A14＝0.0000E+00

The 7 th plane

K＝-5.778，A3＝0.0000E+00，A4＝-7.6930E-03，A5＝0.0000E+00，

A6＝3.8230E-03，A7＝0.0000E+00，A8＝-1.1120E-03，

A9＝0.0000E+00，

A10＝1.4666E-04，A11＝0.0000E+00，A12＝2.5484E-05，

A13＝0.0000E+00，

A14＝0.0000E+00

The 8 th plane

K＝-0.152，A3＝0.0000E+00，A4＝1.1415E-02，A5＝0.0000E+00，

A6＝-1.4935E-03，A7＝0.0000E+00，A8＝8.4573E-04，

A9＝0.0000E+00，

A10＝-1.9663E-04，A11＝0.0000E+00，A12＝2.2336E-05，

A13＝0.0000E+00，

A14＝0.0000E+00

The 12 th surface

K＝1.931，A3＝0.0000E+00，A4＝-1.5545E-02，A5＝0.0000E+00，

A6＝4.7387E-02，A7＝0.0000E+00，A8＝-2.0169E-02，

A9＝0.0000E+00，

A10＝2.7025E-03，A11＝0.0000E+00，A12＝5.8141E-03，

A13＝0.0000E+00，

A14＝2.9816E-04

The 13 th side

K＝0.705，A3＝0.0000E+00，A4＝-6.6780E-02，A5＝0.0000E+00，

A6＝3.4333E-02，A7＝0.0000E+00，A8＝-1.3643E-02，

A9＝0.0000E+00，

A10＝-9.0842E-04，A11＝0.0000E+00，A12＝2.0765E-03，

A13＝0.0000E+00，

A14＝-2.9158E-04

The 14 th side

K＝0.986，A3＝7.8709E-03，A4＝-3.0507E-02，A5＝-1.2686E-03，

A6＝1.2926E-02，A7＝-8.1322E-04，A8＝-3.9591E-04，

A9＝1.2353E-04，

A10＝-1.2914E-03，A11＝1.6489E-04，A12＝5.1176E-05，

A13＝3.4655E-05，

A14＝1.9999E-05

The 15 th surface

K＝0.244，A3＝-3.1161E-03，A4＝5.5250E-02，A5＝-2.0293E-03，

A6＝-7.7412E-03，A7＝5.6340E-06，A8＝3.4746E-03，

A9＝1.3149E-04，

A10＝2.1851E-03，A11＝2.2870E-05，A12＝-1.3919E-03，

A13＝1.3934E-05，

A14＝1.9594E-04

Fig. 5A is a sectional view of the imaging optical system 10D and the like of embodiment 4. The imaging optical system 10D includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10D includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51.

Fig. 5B and 5C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10D according to example 4.

(example 5)

The overall specifications of the imaging optical system of example 5 are as follows.

f：0.81(mm)

Fno：2.00

w：109.0(°)

ymax：1.88(mm)

TL：18.04(mm)

BF：1.76(mm)

PDΔ+100：0.011(mm)

PDΔ-65：-0.008(mm)

Data of the lens surface of the imaging optical system of example 5 is shown in table 9 below.

[ Table 9 ]

Image of a person

The aspherical surface coefficients of the lens surface of example 5 are shown in table 10 below.

[ Table 10 ]

No. 3 surface

K＝-43.326，A3＝-1.3463E-03，A4＝2.7568E-02，A5＝1.6996E-04，

A6＝-3.9462E-03，A7＝5.4976E-06，A8＝2.2756E-04，

A9＝-1.1389E-06，

A10＝-5.1485E-06，A11＝-3.5966E-08，A12＝3.5308E-08，

A13＝0.0000E+00，

A14＝0.0000E+00

No. 4 surface

K＝-0.556，A3＝-1.9453E-02，A4＝3.8281E-02，A5＝3.6781E-04，

A6＝1.0732E-02，A7＝-1.9297E-04，A8＝-1.8747E-03，

A9＝2.7190E-05，

A10＝-7.3481E-04，A11＝6.2702E-06，A12＝1.1416E-04，

A13＝0.0000E+00，

A14＝0.0000E+00

The 5 th plane

K＝-50.000，A3＝0.0000E+00，A4＝1.5736E-02，A5＝0.0000E+00，

A6＝4.5509E-03，A7＝0.0000E+00，A8＝-6.0222E-04，

A9＝0.0000E+00，

A10＝-9.7002E-05，A11＝0.0000E+00，A12＝3.0655E-08，

A13＝0.0000E+00，

A14＝0.0000E+00

The 6 th plane

K＝14.606，A3＝0.0000E+00，A4＝-1.4220E-03，A5＝0.0000E+00，

A6＝1.4574E-02，A7＝0.0000E+00，A8＝-4.4709E-03，

A9＝0.0000E+00，

A10＝4.8044E-04，A11＝0.0000E+00，A12＝-1.4399E-06，

A13＝0.0000E+00，

A14＝0.0000E+00

The 7 th plane

K＝-2.153，A3＝0.0000E+00，A4＝-1.1274E-02，A5＝0.0000E+00，

A6＝4.3360E-03，A7＝0.0000E+00，A8＝-7.0573E-04，

A9＝0.0000E+00，

A10＝1.6174E-04，A11＝0.0000E+00，A12＝-1.9886E-06，

A13＝0.0000E+00，

A14＝0.0000E+00

The 8 th plane

K＝-0.504，A3＝0.0000E+00，A4＝1.4891E-02，A5＝0.0000E+00，

A6＝-7.3587E-04，A7＝0.0000E+00，A8＝6.0145E-04，

A9＝0.0000E+00，

A10＝-1.3697E-04，A11＝0.0000E+00，A12＝1.3287E-07，

A13＝0.0000E+00，

A14＝0.0000E+00

The 12 th surface

K＝2.019，A3＝0.0000E+00，A4＝-1.2223E-02，A5＝0.0000E+00，

A6＝4.3372E-02，A7＝0.0000E+00，A8＝-2.0768E-02，

A9＝0.0000E+00，

A10＝2.0672E-03，A11＝0.0000E+00，A12＝4.9736E-03，

A13＝0.0000E+00，

A14＝-1.6863E-04

The 13 th side

K＝1.091，A3＝0.0000E+00，A4＝-6.6179E-02，A5＝0.0000E+00，

A6＝3.7370E-02，A7＝0.0000E+00，A8＝-1.2891E-02，

A9＝0.0000E+00，

A10＝-1.8344E-03，A11＝0.0000E+00，A12＝1.5207E-03，

A13＝0.0000E+00，

A14＝-1.5548E-05

The 14 th side

K＝0.756，A3＝-6.5893E-04，A4＝-3.2252E-02，A5＝-1.4431E-04，

A6＝1.4249E-02，A7＝-5.9184E-05，A8＝-1.6694E-04，

A9＝6.1069E-05，

A10＝-1.4542E-03，A11＝9.2060E-06，A12＝-5.2478E-05，

A13＝-8.5175E-06，

A14＝2.9261E-05

The 15 th surface

K＝0.226，A3＝5.2029E-04，A4＝5.9132E-02，A5＝-1.4943E-04，

A6＝-7.0942E-03，A7＝8.1693E-05，A8＝3.3660E-03，

A9＝1.7558E-05，

A10＝2.1182E-03，A11＝-5.1723E-06，A12＝-1.4048E-03，

A13＝-1.4693E-06，

A14＝1.7112E-04

Fig. 6A is a sectional view of an imaging optical system 10E and the like of embodiment 5. The imaging optical system 10E includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10E includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51.

Fig. 6B and 6C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10E of example 5.

(example 6)

The overall specifications of the imaging optical system of example 6 are as follows.

f：0.73(mm)

Fno：2.00

w：109.0(°)

ymax：2.03(mm)

TL：19.56(mm)

BF：1.64(mm)

PDΔ+100：0.006(mm)

PDΔ-65：-0.004(mm)

Data of the lens surface of the imaging optical system of example 6 is shown in table 11 below.

[ Table 11 ]

Image of a person

The aspherical surface coefficients of the lens surface of example 6 are shown in table 12 below.

[ Table 12 ]

No. 3 surface

K＝-50.000，A3＝-9.1548E-04，A4＝2.7579E-02，A5＝1.6370E-04，

A6＝-3.9497E-03，A7＝4.2265E-06，A8＝2.2727E-04，

A9＝-1.2283E-06，

A10＝-5.1621E-06，A11＝-3.5802E-08，A12＝3.6978E-08，

A13＝0.0000E+00，

A14＝0.0000E+00

No. 4 surface

K＝-0.564，A3＝-1.7505E-02，A4＝3.8270E-02，A5＝4.4551E-06，

A6＝1.0609E-02，A7＝-2.0844E-04，A8＝-1.8642E-03，

A9＝3.8521E-05，

A10＝-7.2849E-04，A11＝8.5372E-06，A12＝1.1428E-04，

A13＝0.0000E+00，

A14＝0.0000E+00

The 5 th plane

K＝-30.526，A3＝0.0000E+00，A4＝1.2311E-02，A5＝0.0000E+00，

A6＝4.5118E-03，A7＝0.0000E+00，A8＝-4.9406E-04，

A9＝0.0000E+00，

A10＝-6.9409E-05，A11＝0.0000E+00，A12＝2.9296E-06，

A13＝0.0000E+00，

A14＝0.0000E+00

The 6 th plane

K＝-3.752，A3＝0.0000E+00，A4＝3.5615E-03，A5＝0.0000E+00，

A6＝1.5732E-02，A7＝0.0000E+00，A8＝-4.3476E-03，

A9＝0.0000E+00，

A10＝5.3509E-04，A11＝0.0000E+00，A12＝9.3207E-06，

A13＝0.0000E+00，

A14＝0.0000E+00

The 7 th plane

K＝-10.730，A3＝0.0000E+00，A4＝-3.0091E-03，A5＝0.0000E+00，

A6＝4.7784E-03，A7＝0.0000E+00，A8＝-1.0003E-03，

A9＝0.0000E+00，

A10＝1.6854E-04，A11＝0.0000E+00，A12＝5.1899E-05，

A13＝0.0000E+00，

A14＝0.0000E+00

The 8 th plane

K＝-0.505，A3＝0.0000E+00，A4＝1.5424E-02，A5＝0.0000E+00，

A6＝-4.0302E-03，A7＝0.0000E+00，A8＝2.7348E-03，

A9＝0.0000E+00，

A10＝-9.6336E-04，A11＝0.0000E+00，A12＝1.6312E-04，

A13＝0.0000E+00，

A14＝0.0000E+00

The 12 th surface

K＝2.458，A3＝0.0000E+00，A4＝-1.7669E-02，A5＝0.0000E+00，

A6＝5.8714E-02，A7＝0.0000E+00，A8＝-5.6091E-02，

A9＝0.0000E+00，

A10＝7.3150E-03，A11＝0.0000E+00，A12＝5.3075E-02，

A13＝0.0000E+00，

A14＝-2.5266E-02

The 13 th side

K＝2.224，A3＝0.0000E+00，A4＝-6.0265E-02，A5＝0.0000E+00，

A6＝2.4575E-02，A7＝0.0000E+00，A8＝-1.8429E-02，

A9＝0.0000E+00，

A10＝1.0305E-03，A11＝0.0000E+00，A12＝4.4917E-03，

A13＝0.0000E+00，

A14＝-1.0437E-03

The 14 th side

K＝2.728，A3＝1.6170E-02，A4＝-2.3219E-02，A5＝2.6594E-03，

A6＝1.4892E-02，A7＝1.7039E-05，A8＝-3.2703E-04，

A9＝-2.5749E-04，

A10＝-1.8105E-03，A11＝-2.5470E-04，A12＝-1.4293E-04，

A13＝9.6073E-05，

A14＝3.0211E-04

The 15 th surface

K＝0.140，A3＝1.3489E-02，A4＝5.9266E-02，A5＝-9.3661E-04，

A6＝-6.6899E-03，A7＝1.3560E-03，A8＝4.8167E-03，

A9＝1.1933E-03，

A10＝2.8629E-03，A11＝3.4374E-04，A12＝-1.3350E-03，

A13＝-8.7402E-05，

A14＝2.3891E-05

Fig. 7A is a sectional view of an imaging optical system 10F and the like of embodiment 6. The imaging optical system 10F includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10F includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51.

Fig. 7B and 7C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10F of example 6.

(example 7)

The overall specifications of the imaging optical system of example 7 are as follows.

f：0.84(mm)

Fno：1.99

w：100.0(°)

ymax：1.84(mm)

TL：19.57(mm)

BF：1.59(mm)

PDΔ+100：0.000(mm)

PDΔ-65：-0.001(mm)

Data of the lens surface of the imaging optical system of example 7 is shown in table 13 below.

[ Table 13 ]

Image of a person

The aspherical surface coefficients of the lens surface of example 7 are shown in table 14 below.

[ Table 14 ]

No. 3 surface

K＝-50.000，A3＝1.8697E-02，A4＝1.9301E-02，A5＝1.2271E-04，

A6＝-3.7715E-03，A7＝3.9243E-05，A8＝2.2534E-04，

A9＝-2.2663E-06，

A10＝-4.8304E-06，A11＝-7.2830E-08，A12＝2.6580E-08，

A13＝0.0000E+00，

A14＝0.0000E+00

No. 4 surface

K＝-0.659，A3＝-3.3934E-02，A4＝3.9438E-02，A5＝2.4686E-03，

A6＝9.3074E-03，A7＝-9.8364E-04，A8＝-2.1815E-03，

A9＝5.5271E-05，

A10＝-6.7812E-04，A11＝3.1759E-05，A12＝1.0921E-04，

A13＝0.0000E+00，

A14＝0.0000E+00

The 5 th plane

K＝-59.852，A3＝0.0000E+00，A4＝3.5244E-03，A5＝0.0000E+00，

A6＝4.6005E-03，A7＝0.0000E+00，A8＝-3.7101E-04，

A9＝0.0000E+00，

A10＝-8.6812E-05，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 6 th plane

K＝25.756，A3＝0.0000E+00，A4＝8.9415E-03，A5＝0.0000E+00，

A6＝1.6607E-02，A7＝0.0000E+00，A8＝-4.3929E-03，

A9＝0.0000E+00，

A10＝5.2797E-04，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 7 th plane

K＝-10.285，A3＝0.0000E+00，A4＝6.0512E-03，A5＝0.0000E+00，

A6＝2.3644E-03，A7＝0.0000E+00，A8＝-1.9557E-03，

A9＝0.0000E+00，

A10＝3.9852E-04，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 8 th plane

K＝0.047，A3＝0.0000E+00，A4＝1.7068E-03，A5＝0.0000E+00，

A6＝-7.3218E-04，A7＝0.0000E+00，A8＝3.7586E-04，

A9＝0.0000E+00，

A10＝-5.2854E-05，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 12 th surface

K＝1.658，A3＝0.0000E+00，A4＝-2.8576E-02，A5＝0.0000E+00，

A6＝5.7440E-02，A7＝0.0000E+00，A8＝-2.1242E-02，

A9＝0.0000E+00，

A10＝-3.6782E-03，A11＝0.0000E+00，A12＝1.6001E-02，

A13＝0.0000E+00，

A14＝0.0000E+00

The 13 th side

K＝1.123，A3＝0.0000E+00，A4＝-8.4925E-02，A5＝0.0000E+00，

A6＝5.0238E-02，A7＝0.0000E+00，A8＝-2.5685E-02，

A9＝0.0000E+00，

A10＝2.6685E-03，A11＝0.0000E+00，A12＝1.0534E-03，

A13＝0.0000E+00，

A14＝0.0000E+00

The 14 th side

K＝0.444，A3＝0.0000E+00，A4＝-3.6392E-02，A5＝0.0000E+00，

A6＝-1.9949E-03，A7＝0.0000E+00，A8＝5.1362E-03，

A9＝0.0000E+00，

A10＝-1.0195E-03，A11＝0.0000E+00，A12＝-5.7271E-04，

A13＝0.0000E+00，

A14＝5.3799E-05

The 15 th surface

K＝0.632，A3＝0.0000E+00，A4＝3.3360E-02，A5＝0.0000E+00，

A6＝-1.5096E-02，A7＝0.0000E+00，A8＝-3.3330E-05，

A9＝0.0000E+00，

A10＝3.3871E-03，A11＝0.0000E+00，A12＝-6.5761E-04，

A13＝0.0000E+00，

A14＝-7.7693E-05

Fig. 8A is a sectional view of an imaging optical system 10G and the like of embodiment 7. The imaging optical system 10G includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10G includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51.

Fig. 8B and 8C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10G of example 7.

(example 8)

The overall specifications of the imaging optical system of example 8 are as follows.

f：0.72(mm)

Fno：1.99

w：100.0(°)

ymax：1.84(mm)

TL：17.68(mm)

BF：1.28(mm)

PDΔ+100：0.013(mm)

PDΔ-65：-0.009(mm)

Data of the lens surface of the imaging optical system of example 8 is shown in table 15 below.

[ Table 15 ]

Image of a person

The aspherical surface coefficients of the lens surface of example 8 are shown in table 16 below.

[ Table 16 ]

No. 3 surface

K＝4.215，A3＝-5.4339E-04，A4＝3.2110E-02，A5＝4.2523E-03，

A6＝-5.2070E-03，A7＝-1.6994E-04，A8＝5.2299E-04，

A9＝-5.9794E-06，

A10＝-4.4408E-05，A11＝7.4808E-06，A12＝-2.8997E-07，

A13＝0.0000E+00，

A14＝0.0000E+00

No. 4 surface

K＝-13.696，A3＝-2.8757E-02，A4＝7.0697E-02，A5＝-2.1760E-02，

A6＝7.9989E-03，A7＝6.6484E-04，A8＝-6.5989E-04，

A9＝9.5381E-04，

A10＝-6.2938E-04，A11＝-1.3947E-05，A12＝3.8557E-05，

A13＝0.0000E+00，

A14＝0.0000E+00

The 5 th plane

K＝0.542，A3＝0.0000E+00，A4＝7.2782E-04，A5＝0.0000E+00，

A6＝2.7095E-03，A7＝0.0000E+00，A8＝-1.1735E-03，

A9＝0.0000E+00，

A10＝8.8907E-05，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 6 th plane

K＝-5.780，A3＝0.0000E+00，A4＝4.4477E-03，A5＝0.0000E+00，

A6＝7.3008E-03，A7＝0.0000E+00，A8＝-3.4235E-03，

A9＝0.0000E+00，

A10＝3.7816E-04，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 7 th plane

K＝-23.012，A3＝0.0000E+00，A4＝3.0402E-02，A5＝0.0000E+00，

A6＝7.3484E-03，A7＝0.0000E+00，A8＝-3.1278E-03，

A9＝0.0000E+00，

A10＝3.4053E-04，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 8 th plane

K＝-0.884，A3＝0.0000E+00，A4＝4.4666E-02，A5＝0.0000E+00，

A6＝-1.4394E-02，A7＝0.0000E+00，A8＝4.7762E-03，

A9＝0.0000E+00，

A10＝-5.4736E-04，A11＝0.0000E+00，A12＝0.0000E+00，

A13＝0.0000E+00，

A14＝0.0000E+00

The 12 th surface

K＝-42.497，A3＝0.0000E+00，A4＝-2.9253E-01，A5＝0.0000E+00，

A6＝1.3887E-01，A7＝0.0000E+00，A8＝-1.1445E-01，

A9＝0.0000E+00，

A10＝9.8885E-02，A11＝0.0000E+00，A12＝-3.3092E-02，

A13＝0.0000E+00，

A14＝0.0000E+00

The 13 th side

K＝-17.046，A3＝0.0000E+00，A4＝-1.0270E-01，A5＝0.0000E+00，

A6＝4.4604E-02，A7＝0.0000E+00，A8＝-6.9698E-03，

A9＝0.0000E+00，

A10＝-2.5803E-03，A11＝0.0000E+00，A12＝3.6186E-04，

A13＝0.0000E+00，

A14＝0.0000E+00

The 14 th side

K＝-10.267，A3＝0.0000E+00，A4＝8.5878E-02，A5＝0.0000E+00，

A6＝-4.4656E-03，A7＝0.0000E+00，A8＝-4.1451E-03，

A9＝0.0000E+00，

A10＝1.1863E-03，A11＝0.0000E+00，A12＝2.6443E-06，

A13＝0.0000E+00，

A14＝-4.2861E-06

The 15 th surface

K＝-0.810，A3＝0.0000E+00，A4＝2.4853E-01，A5＝0.0000E+00，

A6＝-9.2429E-02，A7＝0.0000E+00，A8＝3.7925E-02，

A9＝0.0000E+00，

A10＝3.3610E-03，A11＝0.0000E+00，A12＝-3.7038E-03，

A13＝0.0000E+00，

A14＝6.8361E-04

Fig. 9A is a sectional view of an imaging optical system 10H and the like of embodiment 8. The imaging optical system 10H includes, as the 1 st lens group Gr1, a 1 st lens L1 having a negative refractive power, a 2 nd lens L2 having a negative refractive power, a 3 rd lens L3 having a positive refractive power, and a 4 th lens L4 having a positive refractive power. In addition, the imaging optical system 10H includes, as the 2 nd lens group Gr2, a 5 th lens L5 having a positive refractive power, a 6 th lens L6 having a negative refractive power, and a 7 th lens L7 having a positive refractive power. The 1 st lens L1 and the 5 th lens L5 are formed of glass. The 2 nd lens L2, the 3 rd lens L3, the 4 th lens L4, the 6 th lens L6, and the 7 th lens L7 are formed of plastic. An aperture stop ST is disposed between the 4 th lens L4 and the 5 th lens L5. A filter F having an appropriate thickness is disposed between the 7 th lens L7 and the image pickup device 51.

Fig. 9B and 9C show aberration diagrams (spherical aberration and astigmatism) of the imaging optical system 10H of example 8.

The following table 17 is a table summarizing the values of examples 1 to 8 corresponding to conditional expressions (1) to (10) for reference.

[ Table 17 ]

As described above, in the case of actual lens measurement, the radius of curvature of the lens surface referred to in the present application is an approximate radius of curvature when a shape measurement value in the vicinity of the center of the lens (specifically, a central region within 10% of the outer diameter of the lens) is fitted by the least square method. For example, when 2-order aspherical surface coefficients are used, the reference curvature radius of the aspherical surface definitional expression also includes a curvature radius considering 2-order aspherical surface coefficients.

While the imaging optical system and the like have been described above in accordance with the embodiments, the imaging optical system of the present invention is not limited to the above-described embodiments or examples, and various modifications are possible.

In the above-described embodiment, the filter F may be configured to be switchable when imaging with visible light or near-infrared light is performed in an application such as an in-vehicle camera or a monitoring camera.

In the above embodiment, the lenses L1 to L7 are fixed to the lens barrel 41, but can be moved appropriately to perform focusing and the like.

Claims (15)

1. An imaging optical system includes, in order from an object side:

a 1 st lens group substantially composed of a 1 st lens having a negative refractive power, a 2 nd lens having a negative refractive power, a 3 rd lens having a positive refractive power, and a 4 th lens having a positive refractive power in this order from the object side;

an aperture diaphragm; and

a 2 nd lens group substantially composed of, in order from the object side, a 5 th lens having a positive refractive power, a 6 th lens having a negative refractive power, and a 7 th lens having a positive refractive power,

the 4 th lens has a meniscus shape with a concave surface toward the object side,

the imaging optical system satisfies the following conditional expression,

8≤f4/f≤15 …(1)

wherein the content of the first and second substances,

f 4: a focal length of the 4 th lens;

f: focal length of the entire system of the lens.

2. The imaging optical system according to claim 1,

the imaging optical system satisfies the following conditional expression,

1.9≤d23/f≤3 …(2)

wherein the content of the first and second substances,

d 23: an air space between the 2 nd lens and the 3 rd lens on an optical axis;

f: focal length of the entire system of the lens.

3. The imaging optical system according to claim 1 or 2,

the imaging optical system satisfies the following conditional expression,

0.3≤d34/f≤0.8 …(3)

wherein the content of the first and second substances,

d 34: an air space between the 3 rd lens and the 4 th lens on an optical axis;

f: focal length of the entire system of the lens.

4. The imaging optical system according to claim 1 or 2,

the imaging optical system satisfies the following conditional expression,

0.2≤d67/f≤0.4 …(4)

wherein the content of the first and second substances,

d 67: an air space between the 6 th lens and the 7 th lens on an optical axis;

f: focal length of the entire system of the lens.

5. The imaging optical system according to claim 1 or 2,

the imaging optical system satisfies the following conditional expression,

0.5≤f1/f2≤5 …(5)

wherein the content of the first and second substances,

f 1: a focal length of the 1 st lens;

f 2: focal length of the 2 nd lens.

6. The imaging optical system according to claim 1 or 2,

the imaging optical system satisfies the following conditional expression,

-12≤(r4i+r4o)/(r4i-r4o)<-1 …(6)

wherein the content of the first and second substances,

r4 i: a radius of curvature of an image-side surface of the 4 th lens;

r4 o: a radius of curvature of an object side surface of the 4 th lens.

7. The imaging optical system according to claim 1 or 2,

the imaging optical system satisfies the following conditional expression,

-12≤(r4i+r4o)/(r4i-r4o)≤-1.5 …(7)

wherein the content of the first and second substances,

r4 i: a radius of curvature of an image-side surface of the 4 th lens;

r4 o: a radius of curvature of an object side surface of the 4 th lens.

8. The imaging optical system according to claim 1 or 2,

the imaging optical system satisfies the following conditional expression,

2≤f7/f≤4 …(8)

wherein the content of the first and second substances,

f 7: a focal length of the 7 th lens;

f: focal length of the entire system of the lens.

9. The imaging optical system according to claim 1 or 2,

the 6 th lens has a biconcave shape.

10. The imaging optical system according to claim 1 or 2,

the imaging optical system satisfies the following conditional expression,

-6≤f6/f≤-2 …(9)

wherein the content of the first and second substances,

f 6: a focal length of the 6 th lens;

f: focal length of the entire system of the lens.

11. The imaging optical system according to claim 1 or 2,

3 lenses out of the 4 lenses of the 1 st lens group are formed of plastic,

the 2 nd lens group has 1 lens having a positive refractive power formed of plastic and 1 lens having a negative refractive power formed of plastic,

the imaging optical system satisfies the following conditional expression,

-0.32≤f×Σ(1/fplk)≤0.32 …(10)

wherein the content of the first and second substances,

f: focal length of the entire system of the lens;

fplk: a focal length of the k-th plastic lens from the object side.

12. The imaging optical system according to claim 1 or 2,

the object side surface of the 2 nd lens element has a concave shape toward the object side in the vicinity of the optical axis, and is positioned on the image side of the surface vertex at the effective diameter position.

13. A lens member, comprising:

the image pickup optical system according to any one of claims 1 to 12; and

a lens barrel holding the image pickup optical system.

14. An imaging device is provided with:

the image pickup optical system according to any one of claims 1 to 12; and

and an imaging element for detecting an image obtained from the imaging optical system.

15. The image pickup apparatus according to claim 14,

the imaging device includes a lens barrel that holds the imaging optical system.

Images