JPWO2019044934A1 - Single focus imaging optics, lens unit, and imaging device - Google Patents

Abstract

Provided is a single focus imaging optical system having a wide angle of view, a small size, and high optical performance. The single-focus imaging optical system 10 includes a first lens L1 having a negative refractive power, a biconcave second lens L2, a biconvex third lens L3, an aperture ST, and positive in order from the object side. The fourth lens L4 having the refractive power of the above, the negative fifth lens L5 having the convex surface on the side surface of the object in the near-axis region, and the sixth lens L6 having the positive refractive power are substantially formed.

Description

The present invention relates to a wide-angle single-focus imaging optical system, a lens unit, and an imaging device, and more particularly to a single-focus imaging optical system having an angle of view of 180 ° or more.

In recent years, there has been a demand for an in-vehicle imaging optical system having an angle of view of 180 ° or more, which is compact and has high resolution. As this type of imaging optical system, a six-lens configuration in which a negative lens, a negative lens, a positive lens, a positive lens, a negative lens, and a positive lens are arranged in order from the object side, and the surface on the image side of the third lens is flat or A concave surface is known (see, for example, Patent Document 1).

However, although the imaging optical system of Patent Document 1 can secure a wide angle of view, it has a long optical total length, a large curvature of field, a low peripheral illumination ratio, and the like from the viewpoint of the size and optical performance of the optical system. It could not be said that the above requirements were fully satisfied.

Japanese Unexamined Patent Publication No. 2013-73141

The present invention has been made in view of the above background technology, and an object of the present invention is to provide a single-focus imaging optical system having a wide angle of view, a small size, and high optical performance.

Another object of the present invention is to provide a lens unit and an imaging device provided with the above-mentioned single focus imaging optical system.

In order to achieve at least one of the above-mentioned objects, the single-focus imaging optical system reflecting one aspect of the present invention includes a first lens having a negative refractive power and a biconcave first lens in order from the object side. It has two lenses, a biconvex third lens, an aperture, a fourth lens having a positive refractive power, a negative fifth lens having a convex surface on the side of the object in the near axis region, and a positive refractive power. Substantially from the sixth lens.

In order to achieve at least one of the above-mentioned objects, a lens unit reflecting one aspect of the present invention includes the above-mentioned single focus imaging optical system and a lens barrel holding the single focus imaging optical system.

In order to realize at least one of the above-mentioned objects, an image pickup device reflecting one aspect of the present invention includes the above-mentioned single focus imaging optical system and an image pickup device that detects an image obtained from the single focus imaging optical system. To be equipped with.

It is a figure explaining the image pickup apparatus provided with the single focus image pickup optical system which is one Embodiment of this invention. FIG. 2A is a cross-sectional view of the single focus imaging optical system of Example 1, and FIGS. 2B and 2C are longitudinal aberration diagrams of Example 1. FIG. 3A is a cross-sectional view of the single focus imaging optical system of the second embodiment, and FIGS. 3B and 3C are longitudinal aberration diagrams of the second embodiment. 4A is a cross-sectional view of the single focus imaging optical system of Example 3, and FIGS. 4B and 4C are longitudinal aberration diagrams of Example 3. 5A is a cross-sectional view of the single focus imaging optical system of Example 4, and FIGS. 5B and 5C are longitudinal aberration diagrams of Example 4. 6A is a cross-sectional view of the single focus imaging optical system of Example 5, and FIGS. 6B and 6C are longitudinal aberration diagrams of Example 5. FIG. 7A is a cross-sectional view of the single focus imaging optical system of Example 6, and FIGS. 7B and 7C are longitudinal aberration diagrams of Example 6. 8A is a cross-sectional view of the single focus imaging optical system of Example 7, and FIGS. 8B and 8C are longitudinal aberration diagrams of Example 7. 9A is a cross-sectional view of the single focus imaging optical system of Example 8, and FIGS. 9B and 9C are longitudinal aberration diagrams of Example 8. 10A is a cross-sectional view of the single focus imaging optical system of Example 9, and FIGS. 10B and 10C are longitudinal aberration diagrams of Example 9.

FIG. 1 is a diagram showing an image pickup apparatus 100 according to an embodiment of the present invention. The image pickup device 100 includes a camera module 30 for forming an image signal, and a processing unit 60 that exerts a function as the image pickup device 100 by operating the camera module 30.

The camera module 30 includes a lens unit 40 including a single focus imaging optical system 10 and a sensor unit 50 that converts a subject image formed by the single focus imaging optical system 10 into an image signal. The camera module 30 incorporates the single focus imaging optical system 10 described in detail below, and can provide an imaging device 100 that secures a wide angle of view, is compact, and has high optical performance.

The lens unit 40 includes a single-focus imaging optical system 10 which is a wide-angle optical system, and a lens barrel 41 to which the single-focus imaging optical system 10 is assembled.

As will be described in detail later, the single focus imaging optical system 10 includes first to sixth lenses L1 to L6, and first to third lenses L1 to L3 forming a front group on the object side with the aperture ST interposed therebetween. It has 4th to 6th lenses L4 to L6 which form a rear group on the image side.

The lens barrel 41 is made of metal, resin, a mixture of resin and glass fiber, or the like, and houses and holds the single focus imaging optical system 10. When the lens barrel 41 is formed of a mixture of metal, resin and glass fiber, it is less likely to expand than resin, and the single focus imaging optical system 10 can be stably fixed. The lens barrel 41 has an opening OP1 for incident a bundle of light rays from the object side.

The first to sixth lenses L1 to L6 constituting the single focus imaging optical system 10 are directly or indirectly held on the inner surface side of the lens barrel 41 at their flanges or outer peripheral portions, and are directly or indirectly held in the optical axis AX direction. And positioning is done in the direction perpendicular to the optical axis AX.

The sensor unit 50 includes a solid-state image sensor 51 that photoelectrically converts a subject image formed by the single-focus image pickup optical system 10, and a substrate 52 that supports the solid-state image sensor 51 from behind and is provided with wiring, peripheral circuits, and the like. It includes a sensor holder 53 that holds the solid-state image sensor 51 via the substrate 52. The solid-state image sensor 51 is, for example, a CMOS type image sensor. The substrate 52 includes wiring, peripheral circuits, and the like for operating the solid-state image sensor 51. The sensor holder 53 is made of resin or other material, and not only positions the solid-state image sensor 51 with respect to the optical axis AX, but also supports the parallel flat plate F so as to face the solid-state image sensor 51. The lens barrel 41 of the lens unit 40 is fixed in a positioned state so as to fit into the sensor holder 53.

The solid-state image sensor (image sensor) 51 includes a photoelectric conversion unit 51a having an image pickup surface I, and a signal processing circuit (not shown) is formed around the photoelectric conversion unit 51a. The solid-state image sensor 51 is not limited to the above-mentioned CMOS type image sensor, and may be a CCD or the like.

The parallel plate F arranged between the single focus image pickup optical system 10 and the solid-state image pickup element 51 is an optical low-pass filter, a seal glass of the solid-state image pickup element, an IR cut filter, a wavelength selection filter, and the like.

The processing unit 60 includes a drive unit 61, an input unit 62, a storage unit 63, a display unit 64, and a control unit 68. The drive unit 61 operates the solid-state image sensor 51 by receiving a supply of a digital control signal or the like from the control unit 68. The drive unit 61 receives YUV or other digital pixel signals as image data from the solid-state image sensor 51 and transfers them to the control unit 68. The input unit 62 is a part that receives a user's operation or a command from an external device, and the storage unit 63 is a part that stores information necessary for the operation of the image pickup device 100, image data acquired by the camera module 30, and the like. The display unit 64 is a portion that displays information to be presented to the user, a captured image, and the like. The control unit 68 comprehensively controls the operations of the drive unit 61, the input unit 62, the storage unit 63, and the like, and can perform various image processing on the image data obtained by, for example, the camera module 30. Such image data can be output to an external circuit.

Hereinafter, the details of the single focus imaging optical system 10 of the embodiment will be described with reference to FIG. The single focus imaging optical system 10 illustrated in FIG. 1 has the same configuration as the single focus imaging optical system 10A of the first embodiment described later.

The illustrated single-focus imaging optical system 10 is a wide-angle lens that forms a subject image on the imaging surface I of the solid-state imaging element 51, and is a first lens L1 having a negative refractive power in order from the object side. Concave second lens L2, biconvex third lens L3, aperture ST, fourth lens L4 with positive refractive power, negative fifth lens L5 with convex object side surface in near-axis region, and positive It is composed of a sixth lens L6 having a refractive power of. Here, the first lens L1 is a spherical type lens formed of glass and formed of a spherical surface, and the fourth lens L4 is an aspherical type lens formed of glass and formed of an aspherical surface. .. The second, third, fifth, and sixth lenses L2, L3, L5, and L6 are each made of plastic and have at least one aspherical shape.

This single focus image pickup optical system 10 is a wide-angle lens having an angle of view of 180 ° or more, and by adopting a retrofocus type that precedes a negative lens, the front lens diameter can be reduced, and a parallel flat plate F that functions as various filters, a solid Sufficient back focus can be secured for installing the sealing glass or the like of the image sensor 51. Further, by forming the negative lens into two lenses, the first lens and the second lens L1 and L2, the negative power can be divided, and the performance can be improved and the error sensitivity can be reduced as compared with the case where the negative lens is one lens. .. Further, by making the third lens L3 a biconvex shape, sufficient positive power is secured, and aberrations generated by the negative lenses of the first lens L1 and the second lens L2 are canceled in the lens group before the aperture ST. Good optical performance can be ensured. Further, by arranging the 4th lens L4, the 5th lens L5, and the 6th lens L6 in a positive / negative / positive power arrangement, a so-called triplet is formed, and aberration correction in the lens group behind the aperture ST becomes good. Further, when the object side surface S51 of the fifth lens L5 is convex in the near axis region, the distance between the principal points of the fourth lens L4 and the fifth lens L5 is widened, and the fourth and fifth lenses L4 and L5 have the same power, respectively. However, since the combined power of the 4th lens L4 and the 5th lens L5 can be strengthened as compared with the case where the principal point spacing is narrow, the aberration and error sensitivity generated in each of the 4th and 5th lenses L4 and L5 are suppressed. At the same time, the single focus imaging optical system 10 can be miniaturized. The fourth and fifth lenses L4 and L5, the fifth and sixth lenses L5 and L6, and the like may be joined to each other in order to suppress chromatic aberration, spherical aberration, and error sensitivity.

The single focus imaging optical system 10 satisfies the following conditional expression (1).
0.1 <(d34 / f) / (tan (w / 2)) <0.8 ... (1)
Here, the value d34 is the distance between the third lens L3 and the fourth lens L4, the value f is the focal length of the entire system, and the value w is the maximum half angle of view.

When the value (d34 / f) / (tan (w / 2)) of the above conditional expression (1) exceeds the lower limit, the distance between the third lens L3 and the fourth lens L4 does not become too narrow, and interference can be prevented. Or, the error sensitivity of both lenses can be suppressed. On the other hand, when the value (d34 / f) / (tan (w / 2)) of the above conditional expression is less than the upper limit, it is possible to prevent the optical system from becoming large.

The single focus imaging optical system 10 satisfies the following conditional expression (2).
-3 ≤ f2 / f ≤ -1 ... (2)
Here, the value f2 is the focal length of the second lens L2.

By setting the value f2 / f of the above conditional expression (2) to the upper limit or less, the refractive power of the second lens L2 does not become too strong, and astigmatism generated here and performance fluctuation due to manufacturing error can be suppressed. it can. On the other hand, by setting the value f2 / f of the conditional expression (2) to the lower limit or more, the refractive power of the second lens L2 does not become too weak, and the optical system can be kept compact.

The single focus imaging optical system 10 satisfies the following conditional expression (3).
3 ≦ f3 / f ≦ 6… (3)
Here, the value f3 is the focal length of the third lens L3.

By setting the value f3 / f of the above conditional expression (3) to the lower limit or higher, the refractive power of the third lens L3 does not become too strong, and the spherical aberration and coma aberration generated here and the performance fluctuation due to the manufacturing error are suppressed. be able to. On the other hand, by setting the value f3 / f of the conditional expression (3) to the upper limit or less, the refractive power of the third lens L3 does not become too weak, and the optical system can be kept compact.

The single focus imaging optical system 10 satisfies the following conditional expression (4).
-3 ≤ f5 / f ≤ -1 ... (4)
Here, the value f5 is the focal length of the fifth lens.

By setting the value f5 / f of the above conditional expression (4) to the upper limit or less, the refractive power of the fifth lens L5 does not become too strong, and astigmatism generated here and performance fluctuation due to manufacturing error can be suppressed. it can. On the other hand, by setting the value f5 / f of the conditional expression (4) to the lower limit or more, the refractive power of the fifth lens L5 does not become too weak, and the optical system can be kept compact.

The single focus imaging optical system 10 satisfies the following conditional expression (5).
2 ≦ f1 / f2 ≦ 5.5… (5)

By setting the value f1 / f2 of the above conditional expression (5) to the lower limit or higher, the refractive power of the first lens L1 does not become too strong with respect to the second lens L2, and the burden on the first lens L1 can be relatively reduced. , Astigmatism and error sensitivity generated by the first lens L1 can be suppressed. On the other hand, by setting the value f1 / f2 of the above conditional expression (5) to the upper limit or less, the refractive power of the second lens L2 does not become too strong with respect to the first lens L1, and the burden on the second lens L2 is relatively reduced. Therefore, astigmatism and error sensitivity generated by the second lens L2 can be suppressed.

The single focus imaging optical system 10 satisfies the following conditional expression (6).
-8 ≤ f1 / f ≤ -5 ... (6)

By setting the value f1 / f of the above conditional expression (6) to the upper limit or less, the refractive power of the first lens L1 does not become too strong, and astigmatism generated here and performance fluctuation due to manufacturing error can be suppressed. it can. On the other hand, by setting the value f1 / f of the above conditional expression (6) to the lower limit or higher, the refractive power of the first lens L1 does not become too weak, the front lens diameter does not become too large, and the optical system is kept small. can do.

The single focus imaging optical system 10 satisfies the following conditional expression (7).
1.5 ≤ f4 / f ≤ 3 ... (7)
Here, the value f4 is the focal length of the fourth lens L4.

By setting the value f4 / f of the above conditional equation (7) to the lower limit or higher, the refractive power of the fourth lens L4 does not become too strong, and the spherical aberration and coma aberration generated here and the performance fluctuation due to the manufacturing error are suppressed. be able to. On the other hand, by setting the value f4 / f of the conditional expression (7) to the upper limit or less, the refractive power of the fourth lens L4 does not become too weak, and the optical system can be kept compact.

The single focus imaging optical system 10 satisfies the following conditional expression (8).
−0.4 ≦ f × Σ (1 / fplk) ≦ −0.2… (8)
Here, the value fplk is the focal length of the kth plastic lens from the object side.

As described above, by using the second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6 as plastic lenses, one set of positive and negative power plastic lenses is arranged before and after the aperture. It is possible to suppress focus movement and aberration fluctuation when the temperature changes. Here, the second lens L2 has k = 1, the third lens L3 has k = 2, the fifth lens L5 has k = 3, and the sixth lens L6 has k = 4. Further, by setting the value f × Σ (1 / fplk) of the above conditional expression (8) to be equal to or higher than the lower limit, the sum of the focal lengths of the plastic lenses does not become too large on the negative value side, so that the temperature becomes higher on the high temperature side. The distance from the lens to the focal point does not have to be too short when the temperature changes, and the distance from the lens to the focal point does not have to be too long when the temperature changes to the low temperature side. On the other hand, by setting the value f × Σ (1 / fplk) of the above conditional expression (8) to the upper limit or less, the sum of the focal lengths of the plastic lenses does not become too small on the negative value side, so that the temperature becomes higher on the high temperature side. The distance from the lens to the focal point does not have to be too long when the temperature changes, and the distance from the lens to the focal point does not have to be too short when the temperature changes to the low temperature side. In addition, the lenses L2, L3, L5, and L6 are made of plastic to reduce the weight of the optical system, and by adding an aspherical surface by injection molding or the like, the degree of freedom in shape is increased as compared with the spherical surface, and aberrations are corrected well. Can be done.

The single focus imaging optical system 10 satisfies the following conditional expression (9).
νL4 ≧ 65… (9)
Here, the value νL4 is the Abbe number of the fourth lens L4.

By satisfying the above conditional expression (9), the chromatic aberration generated by the fourth lens L4 can be suppressed to a small value. Regarding the value νL4,
νL4 ≧ 70
If you set it to, the effect will increase.
νL4 ≧ 75
If set to, the effect will be further enhanced.

The single focus imaging optical system 10 satisfies the following conditional expression (10).
1.8 ≤ nL1 ... (10)
Here, the value nL1 is the refractive index of the first lens L1.

By satisfying the above conditional expression (10), the radius of curvature can be loosened even if the first lens L1 has the same power, and astigmatism and the like generated on this surface can be suppressed to a small value. Further, even if the power of the first lens L1 is increased to reduce the diameter of the front lens, aberrations are relatively unlikely to occur, and it is possible to achieve both miniaturization and high performance of the optical system.

The single focus imaging optical system 10 may further have other optical elements (for example, a lens, a filter member, etc.) having substantially no refractive power.

The single focus imaging optical system 10 of the present embodiment is premised on being used for a fixed focus camera module 30 or an imaging device 100 having no focus function. That is, the lens barrel 41 is not provided with a movable lens mechanism.

The parallel flat plate F is not indispensable. For example, it is desirable that the filter for wavelength selection is not arranged as a separate body but is provided with the function thereof. For example, in the case of an infrared cut filter, an infrared cut coat may be applied on the surface of one or a plurality of lenses.

Applications of the single-focus imaging optical system 10 or the imaging device 100 include security cameras such as surveillance cameras, doorphone cameras, and authentication cameras, lenses for marketing cameras, lenses for in-vehicle cameras mounted on automobiles and other moving objects, and medical cameras. Examples include endoscopes, healthcare measurements, industrial endoscopes and other medical or industrial optical lenses. Of course, the single focus imaging optical system 10 or the imaging device 100 may be applied to applications in which a wide angle is required in addition to these.

〔Example〕
Hereinafter, examples of the single focus imaging optical system according to the present invention will be shown. The symbols used in each embodiment are as follows. The unit of the length is mm unless otherwise specified, and the unit of the angle is ° (degree).
Fno: F value w: Maximum half angle of view R: Radius of curvature d: Axis top surface interval nd: Refractive index of lens material with respect to d line νd: Abbe number of lens material ymax: Maximum image height TL: Optical total length BF: From the final surface Distance to posterior focus

ただし、
Ａｉ：ｉ次の非球面係数
Ｒ ：曲率半径
Ｋ ：円錐定数In each embodiment, the surface in which "*" is described after each surface number is a surface having an aspherical shape, and the aspherical shape has the aspherical surface as the origin and the X axis in the optical axis direction. , The height in the direction perpendicular to the optical axis is represented by the following "Equation 1" as h.

However,
Ai: i-order aspherical coefficient R: radius of curvature K: conical constant

(Example 1)
The overall specifications of the single focus imaging optical system of Example 1 are shown in Table 1 below.
[Table 1]
f (mm) 1.28
Fno 2.0
w (°) 110.0
ymax (mm) 2.64
TL (mm) 17.28
BF (mm) 2.41

The data of the lens surface of the single focus imaging optical system of Example 1 is shown in Table 2 below. In Table 1 and the like below, the surface number is represented by "Surf. N", the aperture stop is represented by "ST", and infinity is represented by "INF". Further, "image" represents the image pickup surface I (or the image plane of the single focus image pickup optical system) of the image pickup device.
[Table 2]
Surf.NR (mm) d (mm) nd νd
1 14.948 1.95 1.80422 46.5
2 4.478 2.84
3 * -15.768 0.80 1.54537 56.1
4 * 1.522 1.86
5 * 3.579 2.70 1.63414 23.8
6 * -91.690 0.10
7 (ST) INF 0.19
8 * 3.991 1.56 1.49707 81.5
9 * -1.771 0.10
10 * 83.435 0.50 1.63414 23.8
11 * 1.661 0.21
12 * 4.703 1.83 1.54537 56.1
13 * -2.402 1.75
14 INF 0.70 1.51680 64.2
15 INF 0.19
image INF

The aspherical coefficients of the lens surface of the single focus imaging optical system of Example 1 are shown in Table 3 below. In the following it (including lens data in Tables), and represents an exponent of 10 (for example, 2.5 × ^{10 -02)} with E (e.g. 2.5E-02).
[Table 3]
Third side
K = 8.177, A3 = 2.9122E-03, A4 = 6.8859E-03, A5 = 1.2882E-04,
A6 = -1.4675E-03, A7 = 5.4797E-06, A8 = 3.7579E-04, A10 = -1.1690E-04,
A12 = 2.5813E-05, A14 = -3.5407E-06, A16 = 2.9886E-07, A18 = -1.3003E-08,
A20 = 2.4619E-10
4th side
K = -0.618, A3 = -1.8403E-02, A4 = 2.7319E-02, A5 = -1.7877E-02,
A6 = 6.8163E-02, A7 = 1.4196E-03, A8 = -1.4395E-01, A10 = 1.7561E-01,
A12 = -1.2736E-01, A14 = 5.6561E-02, A16 = -1.5128E-02, A18 = 2.2408E-03,
A20 = -1.4118E-04
Side 5
K = -1.339, A3 = 5.6058E-03, A4 = -8.3782E-03, A5 = 7.4303E-03,
A6 = 5.0572E-03, A7 = -4.3043E-03, A8 = -6.8056E-04, A10 = 1.1515E-03,
A12 = -2.6825E-04, A14 = 2.4781E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.1601E-02, A4 = -4.2851E-02, A5 = 3.9594E-02,
A6 = 9.3009E-03, A7 = -3.0137E-02, A8 = 1.5370E-02, A10 = 4.0880E-03,
A12 = -3.7404E-03, A14 = 1.9481E-03, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = 1.566, A3 = 0.000E + 00, A4 = -2.5562E-02, A5 = 0.000E + 00,
A6 = 5.1635E-03, A7 = 0.000E + 00, A8 = 1.8542E-03, A10 = 6.4855E-04,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -1.279, A3 = 0.000E + 00, A4 = -3.5301E-02, A5 = 0.000E + 00,
A6 = 4.7025E-02, A7 = 0.000E + 00, A8 = -2.9033E-02, A10 = 7.2750E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = -50.000, A3 = 8.2491E-03, A4 = -1.7870E-01, A5 = -3.1470E-02,
A6 = 1.4931E-01, A7 = 4.5245E-03, A8 = -7.4142E-02, A10 = 2.1139E-02,
A12 = -2.4474E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -5.043, A3 = 5.7907E-03, A4 = -3.5754E-02, A5 = -7.1703E-03,
A6 = 2.3103E-02, A7 = 9.6540E-04, A8 = -5.9669E-03, A10 = 1.3702E-04,
A12 = 2.4155E-04, A14 = -3.7281E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.031, A3 = -1.4788E-03, A4 = 2.6926E-02, A5 = 8.8579E-04,
A6 = -2.7672E-02, A7 = -1.7193E-04, A8 = 1.2452E-02, A10 = -3.0937E-03,
A12 = 4.0798E-04, A14 = -2.1747E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.597, A3 = 1.2010E-02, A4 = -1.8975E-02, A5 = 3.3317E-03,
A6 = 1.8603E-03, A7 = -7.8071E-04, A8 = 1.4932E-03, A10 = -8.8219E-04,
A12 = 2.4340E-04, A14 = -2.1285E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 2A is a cross-sectional view of the single focus imaging optical system 10A and the like according to the first embodiment. Specifically, in the single focus imaging optical system 10A, the negative first lens L1, the negative second lens L2, the positive third lens L3, the aperture (or aperture aperture) ST, and the positive first lens are arranged in this order from the object side. It consists substantially of four lenses L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate (filter) F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51. The parallel flat plate (filter) F is a parallel flat plate assuming an optical low-pass filter, an IR cut filter, a seal glass of the solid-state image sensor 51, and the like. Reference numeral I numeral I indicates an image pickup surface which is a projection plane of the solid-state image sensor 51. The same applies to the reference numerals F and I in the following examples.

2B and 2C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10A of the first embodiment. In the spherical aberration diagram, "F2.0" represents an F value. In the above astigmatism diagram, the solid line represents the sagittal image plane and the dotted line represents the meridional image plane.

In the single focus imaging optical system 10A of Example 1, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is −0.012 mm.

(Example 2)
The overall specifications of the single focus imaging optical system of Example 2 are shown in Table 4 below.
[Table 4]
f (mm) 1.29
Fno 2.0
w (°) 110.0
ymax (mm) 2.63
TL (mm) 17.08
BF (mm) 2.41

The data of the lens surface of the single focus imaging optical system of Example 2 is shown in Table 5 below.
[Table 5]
Surf.NR (mm) d (mm) nd νd
1 13.676 1.52 1.80422 46.5
2 4.215 3.15
3 * -14.962 0.72 1.54537 56.1
4 * 1.562 1.52
5 * 4.199 1.83 1.63414 23.8
6 * -14.009 1.07
7 (ST) INF 0.31
8 * 3.425 1.49 1.49707 81.5
9 * -2.071 0.10
10 * 14.034 0.50 1.63414 23.8
11 * 1.532 0.22
12 * 4.648 1.99 1.54537 56.1
13 * -2.386 1.80
14 INF 0.70 1.51680 64.2
15 INF 0.16
image INF

The aspherical coefficients of the lens surface of the single focus imaging optical system of Example 2 are shown in Table 6 below.
[Table 6]
Third side
K = 7.566, A3 = 2.4059E-03, A4 = 6.7886E-03, A5 = 1.5876E-04,
A6 = -1.4531E-03, A7 = 1.0861E-05, A8 = 3.7756E-04, A10 = -1.1694E-04,
A12 = 2.5800E-05, A14 = -3.5419E-06, A16 = 2.8990E-07, A18 = -1.3000E-08,
A20 = 2.4614E-10
4th side
K = -0.636, A3 = -1.7963E-02, A4 = 2.6297E-02, A5 = -2.2119E-02,
A6 = 6.7525E-02, A7 = 2.3796E-03, A8 = -1.4308E-01, A10 = 1.7545E-01,
A12 = -1.2752E-01, A14 = 5.6559E-02, A16 = -1.5110E-02, A18 = 2.2467E-03,
A20 = -1.4344E-04
Side 5
K = -6.071, A3 = 1.1727E-02, A4 = -1.7362E-02, A5 = 8.1756E-03,
A6 = 6.3251E-03, A7 = -5.2786E-03, A8 = -1.8255E-03, A10 = 1.1291E-03,
A12 = -7.9217E-05, A14 = -1.6051E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.4495E-02, A4 = -3.7973E-02, A5 = 2.0198E-02,
A6 = 6.2818E-03, A7 = -2.4038E-02, A8 = 1.6241E-02, A10 = -3.5043E-03,
A12 = 7.4491E-04, A14 = -7.9312E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = 2.735, A3 = 0.000E + 00, A4 = -1.6443E-02, A5 = 0.000E + 00,
A6 = -3.5398E-03, A7 = 0.000E + 00, A8 = 1.9832E-04, A10 = -5.3842E-05,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -2.435, A3 = 0.000E + 00, A4 = -2.7758E-02, A5 = 0.000E + 00,
A6 = 4.2115E-02, A7 = 0.000E + 00, A8 = -2.6062E-02, A10 = 5.9446E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = 46.757, A3 = 3.2300E-03, A4 = -1.7990E-01, A5 = -2.7138E-02,
A6 = 1.4965E-01, A7 = 3.2825E-03, A8 = -7.5182E-02, A10 = 2.1153E-02,
A12 = -2.2887E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -5.011, A3 = 5.2164E-03, A4 = -3.5735E-02, A5 = -6.9588E-03,
A6 = 2.3178E-02, A7 = 9.2811E-04, A8 = -6.0244E-03, A10 = 1.3699E-04,
A12 = 2.5233E-04, A14 = -3.8502E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.133, A3 = -1.7423E-03, A4 = 2.6953E-02, A5 = 1.0065E-03,
A6 = -2.7602E-02, A7 = -1.4967E-04, A8 = 1.2445E-02, A10 = -3.1059E-03,
A12 = 4.0522E-04, A14-2.1178E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.436, A3 = 1.6256E-02, A4 = -1.9462E-02, A5 = 3.3046E-03,
A6 = 1.8950E-03, A7 = -7.8831E-04, A8 = 1.4717E-03, A10 = -8.9090E-04,
A12 = 2.4211E-04, A14 = -2.1108E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 3A is a cross-sectional view of the single focus imaging optical system 10B and the like according to the second embodiment. Specifically, in the single focus imaging optical system 10B, the negative first lens L1, the negative second lens L2, the positive third lens L3, the aperture (or aperture aperture) ST, and the positive first lens are arranged in this order from the object side. It consists substantially of four lenses L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

3B and 3C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10B of the second embodiment.

In the single focus imaging optical system 10B of Example 2, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is −0.012 mm.

(Example 3)
The overall specifications of the single focus imaging optical system of Example 3 are shown in Table 7 below.
[Table 7]
f (mm) 1.29
Fno 2.0
w (°) 110.0
ymax (mm) 2.64
TL (mm) 16.86
BF (mm) 2.30

The data of the lens surface of the single focus imaging optical system of Example 3 is shown in Table 8 below.
[Table 8]
Surf.NR (mm) d (mm) nd νd
1 14.663 1.89 1.80422 46.5
2 4.505 2.87
3 * -14.840 0.72 1.54537 56.1
4 * 1.486 1.43
5 * 3.585 2.70 1.63414 23.8
6 * -18.621 0.32
7 (ST) INF 0.19
8 * 4.679 1.54 1.49707 81.5
9 * -1.915 0.10
10 * 64.813 0.50 1.63414 23.8
11 * 1.658 0.20
12 * 4.717 1.86 1.54537 56.1
13 * -2.290 1.66
14 INF 0.70 1.51680 64.2
15 INF 0.18
image INF

The aspherical coefficients of the lens surface of the single focus imaging optical system of Example 3 are shown in Table 9 below.
[Table 9]
Third side
K = 7.594, A3 = 2.1971E-03, A4 = 6.8202E-03, A5 = 1.5609E-04,
A6 = -1.4519E-03, A7 = 1.1047E-05, A8 = 3.7732E-04, A10 = -1.1694E-04,
A12 = 2.5796E-05, A14 = -3.5415E-06, A16 = 2.8988E-07, A18 = -1.2996E-08,
A20 = 2.4596E-10
4th side
K = -0.633, A3 = -1.6093E-02, A4 = 2.5740E-02, A5 = -2.1820E-02,
A6 = 6.7827E-02, A7 = 2.3139E-03, A8 = -1.4322E-01, A10 = 1.7541E-01,
A12 = -1.2750E-01, A14 = 5.6569E-02, A16 = -1.5110E-02, A18 = 2.2451E-03,
A20 = -1.4329E-04
Side 5
K = -3.180, A3 = 9.88086E-03, A4 = -1.3714E-02, A5 = 9.1916E-03,
A6 = 5.9973E-03, A7 = -5.1223E-03, A8 = -1.5073E-03, A10 = 1.1719E-03,
A12 = -1.2353E-04, A14 = -9.5201E-06, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.2089E-02, A4 = -4.5584E-02, A5 = 2.8040E-02,
A6 = 7.3616E-03, A7 = -2.6162E-02, A8 = 1.5622E-02, A10 = -3.3147E-03,
A12 = 1.7671E-03, A14 = -5.5140E-04, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = -0.869, A3 = 0.000E + 00, A4 = -2.4364E-02, A5 = 0.000E + 00,
A6 = 1.1239E-03, A7 = 0.000E + 00, A8 = -5.2247E-03, A10 = 1.8589E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -1.459, A3 = 0.000E + 00, A4 = -3.9516E-02, A5 = 0.000E + 00,
A6 = 4.1884E-02, A7 = 0.000E + 00, A8 = -2.6548E-02, A10 = 5.8226E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = 50.000, A3 = 4.5611E-03, A4 = -1.8509E-01, A5 = -2.8912E-02,
A6 = 1.4998E-01, A7 = 3.8652E-03, A8 = -7.4621E-02, A10 = 2.1403E-02,
A12 = -2.3352E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -5.031, A3 = 2.0367E-03, A4 = -3.6268E-02, A5 = -7.1188E-03,
A6 = 2.3226E-02, A7 = 1.0057E-03, A8 = -5.9646E-03, A10 = 1.4466E-04,
A12 = 2.4795E-04, A14 = -3.9311E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.124, A3 = -2.6877E-03, A4 = 2.6488E-02, A5 = 9.5379E-04,
A6 = -2.7549E-02, A7 = -9.8604E-05, A8 = 1.2480E-02, A10 = -3.0961E-03,
A12 = 4.0643E-04, A14 = -2.1539E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.458, A3 = 1.2938E-02, A4 = -1.9467E-02, A5 = 3.2776E-03,
A6 = 1.9054E-03, A7 = -7.5042E-04, A8 = 1.5131E-03, A10 = -8.7550E-04,
A12 = 2.4485E-04, A14 = -2.1154E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 4A is a cross-sectional view of the single focus imaging optical system 10C and the like according to the third embodiment. Specifically, in the single focus imaging optical system 10C, the negative first lens L1, the negative second lens L2, the positive third lens L3, the aperture (or aperture aperture) ST, and the positive first lens are arranged in this order from the object side. It consists substantially of four lenses L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

4B and 4C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10C of Example 3.

In the single focus imaging optical system 10C of Example 3, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is −0.012 mm.

(Example 4)
The overall specifications of the single focus imaging optical system of Example 4 are shown in Table 10 below.
[Table 10]
f (mm) 1.29
Fno 2.0
w (°) 110.0
ymax (mm) 2.64
TL (mm) 16.83
BF (mm) 2.26

The data of the lens surface of the single focus imaging optical system of Example 4 is shown in Table 11 below.
[Table 11]
Surf.NR (mm) d (mm) nd νd
1 14.657 1.89 1.80422 46.5
2 4.507 2.87
3 * -14.852 0.72 1.54537 56.1
4 * 1.486 1.43
5 * 3.553 2.69 1.63414 23.8
6 * -19.085 0.31
7 (ST) INF 0.19
8 * 4.755 1.56 1.49707 81.5
9 * -2.075 0.10
10 * 74.903 0.50 1.63414 23.8
11 * 1.660 0.20
12 * 4.719 1.85 1.54537 56.1
13 * -2.276 1.63
14 INF 0.70 1.51680 64.2
15 INF 0.16
image INF

The aspherical coefficients of the lens surface of the single focus imaging optical system of Example 4 are shown in Table 12 below.
[Table 12]
Third side
K = 7.569, A3 = 2.2076E-03, A4 = 6.8225E-03, A5 = 1.5660E-04,
A6 = -1.4518E-03, A7 = 1.1071E-05, A8 = 3.7732E-04, A10 = -1.1694E-04,
A12 = 2.5796E-05, A14 = -3.5415E-06, A16 = 2.8988E-07, A18 = -1.2996E-08,
A20 = 2.4597E-10
4th side
K = -0.632, A3 = -1.5977E-02, A4 = 2.5841E-02, A5 = -2.1768E-02,
A6 = 6.7851E-02, A7 = 2.3251E-03, A8 = -1.4322E-01, A10 = 1.7541E-01,
A12 = -1.2750E-01, A14 = 5.6569E-02, A16 = -1.5110E-02, A18 = 2.2451E-03,
A20 = -1.4330E-04
Side 5
K = -3.192, A3 = 9.7628E-03, A4 = -1.3750E-02, A5 = 9.1553E-03,
A6 = 5.9684E-03, A7 = -5.1419E-03, A8 = -1.5193E-03, A10 = 1.1679E-03,
A12 = -1.2491E-04, A14 = -1.0061E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.2670E-02, A4 = -4.6119E-02, A5 = 2.7324E-02,
A6 = 6.8200E-03, A7 = -2.6430E-02, A8 = 1.5607E-02, A10 = -3.0660E-03,
A12 = 1.9365E-03, A14 = -6.5841E-04, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = -0.324, A3 = 0.000E + 00, A4 = -2.3699E-02, A5 = 0.000E + 00,
A6 = 1.8906E-03, A7 = 0.000E + 00, A8 = -4.9243E-03, A10 = 1.6463E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -1.487, A3 = 0.000E + 00, A4 = -3.9228E-02, A5 = 0.000E + 00,
A6 = 4.1926E-02, A7 = 0.000E + 00, A8 = -2.6513E-02, A10 = 5.8457E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = -0.272, A3 = 3.5746E-03, A4 = -1.8542E-01, A5 = -2.9014E-02,
A6 = 1.4994E-01, A7 = 3.8404E-03, A8 = -7.4640E-02, A10 = 2.1391E-02,
A12 = -2.3400E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -4.999, A3 = 2.1857E-03, A4 = -3.6230E-02, A5 = -7.1083E-03,
A6 = 2.3230E-02, A7 = 1.0081E-03, A8 = -5.9632E-03, A10 = 1.4502E-04,
A12 = 2.4795E-04, A14 = -3.9367E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.124, A3 = -2.7572E-03, A4 = 2.6476E-02, A5 = 9.5377E-04,
A6 = -2.7547E-02, A7 = -9.7711E-05, A8 = 1.2480E-02, A10 = -3.0960E-03,
A12 = 4.0649E-04, A14 = -2.1514E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.470, A3 = 1.3169E-02, A4 = -1.9395E-02, A5 = 3.3022E-03,
A6 = 1.9137E-03, A7 = -7.4771E-04, A8 = 1.5139E-03, A10 = -8.7547E-04,
A12 = 2.4483E-04, A14 = -2.1162E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 5A is a cross-sectional view of the single focus imaging optical system 10D and the like according to the fourth embodiment. Specifically, the single focus imaging optical system 10D has a negative first lens L1, a negative second lens L2, a positive third lens L3, an aperture (or aperture aperture) ST, and a positive first lens in order from the object side. It is substantially composed of a 4-lens L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

5B and 5C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10D of Example 4.

In the single focus imaging optical system 10D of Example 4, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when changing from (25 ° C.) to 105 ° C.) is −0.012 mm.

(Example 5)
The overall specifications of the single focus imaging optical system of Example 5 are shown in Table 13 below.
[Table 13]
f (mm) 1.36
Fno 2.0
w (°) 110.0
ymax (mm) 2.64
TL (mm) 19.93
BF (mm) 2.59

The data of the lens surface of the single focus imaging optical system of Example 5 is shown in Table 14 below.
[Table 14]
Surf.NR (mm) d (mm) nd νd
1 13.641 1.27 2.00100 29.1
2 4.441 3.23
3 * -12.988 1.08 1.54438 55.9
4 * 1.795 1.36
5 * 3.018 4.70 1.63469 23.9
6 * -14.499 0.17
7 (ST) INF 0.33
8 * 33.773 1.60 1.49710 81.6
9 * -1.826 0.20
10 * 17.013 0.59 1.63469 23.9
11 * 1.718 0.22
12 * 4.624 2.34 1.54438 55.9
13 * -2.431 2.01
14 INF 0.70 1.51680 64.2
15 INF 0.12
image INF

The aspherical coefficients of the lens surface of the single focus imaging optical system of Example 5 are shown in Table 15 below.
[Table 15]
Third side
K = 9.411, A3 = 0.000E + 00, A4 = -2.0521E-02, A5 = 0.000E + 00,
A6 = 1.2479E-02, A7 = 0.000E + 00, A8 = -3.7741E-03, A10 = 7.2014E-04,
A12 = -9.0731E-05, A14 = 7.5339E-06, A16 = -3.9609E-07, A18 = 1.1935E-08,
A20 = -1.5674E-10
4th side
K = -1.485, A3 = 0.000E + 00, A4 = -2.3021E-02, A5 = 0.000E + 00,
A6 = 1.9503E-02, A7 = 0.000E + 00, A8 = 8.3480E-04, A10 = -4.9068E-03,
A12 = 2.4011E-03, A14 = -6.1203E-04, A16 = 9.0950E-05, A18 = -7.4581E-06,
A20 = 2.6142E-07
Side 5
K = -1.450, A3 = 0.000E + 00, A4 = -1.0160E-03, A5 = 0.000E + 00,
A6 = 4.0835E-03, A7 = 0.000E + 00, A8 = -1.2125E-03, A10 = 2.0421E-04,
A12 = -1.6490E-05, A14 = 5.0560E-07, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = -19.954, A3 = 0.000E + 00, A4 = 1.7114E-02, A5 = 0.000E + 00,
A6 = -6.2859E-03, A7 = 0.000E + 00, A8 = 1.6752E-02, A10 = -1.3667E-02,
A12 = 5.8355E-03, A14 = -5.4258E-04, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = 35.954, A3 = 0.000E + 00, A4 = 8.4661E-04, A5 = 0.000E + 00,
A6 = -3.2797E-03, A7 = 0.000E + 00, A8 = 4.6050E-03, A10 = -6.5564E-04,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -0.485, A3 = 0.000E + 00, A4 = -1.3434E-02, A5 = 0.000E + 00,
A6 = 3.4944E-02, A7 = 0.000E + 00, A8 = -1.6539E-02, A10 = 2.9138E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = -1.579, A3 = 0.000E + 00, A4 = -1.3202E-01, A5 = 0.000E + 00,
A6 = 8.0986E-02, A7 = 0.000E + 00, A8 = -2.8289E-02, A10 = 4.2125E-03,
A12 = -1.6899E-04, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -3.272, A3 = 0.000E + 00, A4 = -4.2411E-02, A5 = 0.000E + 00,
A6 = 1.7833E-02, A7 = 0.000E + 00, A8 = -2.5238E-03, A10 = -6.2600E-04,
A12 = 2.2990E-04, A14 = -2.1021E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 1.767, A3 = 0.000E + 00, A4 = 3.2863E-02, A5 = 0.000E + 00,
A6 = -3.2693E-02, A7 = 0.000E + 00, A8 = 1.4089E-02, A10 = -3.3373E-03,
A12 = 4.2143E-04, A14 = -2.2024E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -7.853, 0A3 = .0000E + 00, A4 = -5.0370E-02, A5 = 0.000E + 00,
A6 = 1.9921E-02, A7 = 0.000E + 00, A8 = -6.0639E-03, A10 = 1.2533E-03,
A12 = -1.6018E-04, A14 = 1.1544E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 6A is a cross-sectional view of the single focus imaging optical system 10E and the like according to the fifth embodiment. Specifically, the single focus imaging optical system 10E has a negative first lens L1, a negative second lens L2, a positive third lens L3, an aperture (or aperture aperture) ST, and a positive first lens in order from the object side. It consists substantially of four lenses L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

6B and 6C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10E of Example 5.

In the single focus imaging optical system 10E of Example 5, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is 0.009 mm.

(Example 6)
The overall specifications of the single focus imaging optical system of Example 6 are shown in Table 16 below.
[Table 16]
f (mm) 1.27
Fno 2.0
w (°) 110.0
ymax (mm) 2.64
TL (mm) 16.00
BF (mm) 2.07

The data of the lens surface of the single focus imaging optical system of Example 6 is shown in Table 17 below.
[Table 17]
Surf.NR (mm) d (mm) nd νd
1 14.150 1.40 1.80422 46.5
2 4.102 2.65
3 * -13.284 0.82 1.54537 56.1
4 * 1.482 1.28
5 * 3.410 2.70 1.63414 23.8
6 * -11.084 0.29
7 (ST) INF 0.25
8 * 4.230 1.53 1.49707 81.5
9 * -1.750 0.10
10 * 11.666 0.53 1.63414 23.8
11 * 1.445 0.22
12 * 4.636 1.92 1.54537 56.1
13 * -2.257 1.43
14 INF 0.70 1.51680 64.2
15 INF 0.18
image INF

The aspherical coefficients of the lens surface of the single focus imaging optical system of Example 6 are shown in Table 18 below.
[Table 18]
Third side
K = 6.579, A3 = 6.4975E-04, A4 = 6.7423E-03, A5 = 2.2214E-04,
A6 = -1.4220E-03, A7 = 1.9470E-05, A8 = 3.7876E-04, A10 = -1.1713E-04,
A12 = 2.5771E-05, A14 = -3.5424E-06, A16 = 2.9004E-07, A18 = -1.2980E-08,
A20 = 2.4437E-10
4th side
K = -0.670, A3 = -1.5731E-02, A4 = 1.9560E-02, A5 = -2.0805E-02,
A6 = 6.9759E-02, A7 = 3.1993E-03, A8 = -1.4333E-01, A10 = 1.7498E-01,
A12 = -1.2757E-01, A14 = 5.6619E-02, A16 = -1.5082E-02, A18 = 2.2492E-03,
A20 = -1.4727E-04
Side 5
K = -6.494, A3 = 1.6669E-02, A4 = -1.2493E-02, A5 = 1.2528E-02,
A6 = 7.5195E-03, A7 = -6.1190E-03, A8 = -2.7179E-03, A10 = 1.2896E-03,
A12 = 1.6865E-04, A14 = -8.2402E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.0915E-02, A4 = -3.5326E-02, A5 = 3.2086E-02,
A6 = 9.0935E-03, A7 = -3.0279E-02, A8 = 1.0125E-02, A10 = 7.9541E-03,
A12 = -4.9947E-03, A14 = 9.3447E-04, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = 2.858, A3 = 0.000E + 00, A4 = -1.6199E-02, A5 = 0.000E + 00,
A6 = -6.5537E-03, A7 = 0.000E + 00, A8 = 2.8076E-03, A10 = -6.5350E-04,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -2.419, A3 = 0.000E + 00, A4 = -3.5022E-02, A5 = 0.000E + 00,
A6 = 3.9984E-02, A7 = 0.000E + 00, A8 = -2.4908E-02, A10 = 5.6758E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = 45.051, A3 = -6.6149E-03, A4 = -1.8398E-01, A5 = -2.6159E-02,
A6 = 1.5133E-01, A7 = 4.4296E-03, A8 = -7.4396E-02, A10 = 2.1255E-02,
A12 = -2.5019E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -5.266, A3 = 1.1979E-03, A4 = -3.641E-02, A5 = -6.7638E-03,
A6 = 2.3594E-02, A7 = 1.2222E-03, A8 = -5.8581E-03, A10 = 1.7421E-04,
A12 = 2.5236E-04, A14 = -4.4786E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.195, A3 = -3.7655E-03, A4 = 2.6364E-02, A5 = 1.0950E-03,
A6 = -2.7424E-02, A7 = -3.7578E-05, A8 = 1.2497E-02, A10 = -3.1019E-03,
A12 = 4.0391E-04, A14 = -2.1616E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.594, A3 = 1.8128E-02, A4 = -1.8119E-02, A5 = 3.9880E-03,
A6 = 2.1913E-03, A7 = -6.9970E-04, A8 = 1.4922E-03, A10 = -8.9053E-04,
A12 = 2.4217E-04, A14 = -2.1167E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 7A is a cross-sectional view of the single focus imaging optical system 10F and the like according to the sixth embodiment. Specifically, the single focus imaging optical system 10F has a negative first lens L1, a negative second lens L2, a positive third lens L3, an aperture (or aperture aperture) ST, and a positive first lens in order from the object side. It consists substantially of four lenses L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

7B and 7C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10F of Example 6.

In the single focus imaging optical system 10F of Example 6, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is −0.009 mm.

(Example 7)
The overall specifications of the single focus imaging optical system of Example 7 are shown in Table 19 below.
[Table 19]
f (mm) 1.07
Fno 2.0
w (°) 110.0
ymax (mm) 2.64
TL (mm) 16.13
BF (mm) 2.06

The data of the lens surface of the single focus imaging optical system of Example 7 is shown in Table 20 below.
[Table 20]
Surf.NR (mm) d (mm) nd νd
1 14.125 1.42 1.80422 46.5
2 4.144 2.69
3 * -13.595 1.01 1.54537 56.1
4 * 1.640 1.31
5 * 4.216 2.70 1.63414 23.8
6 * -27.384 0.16
7 (ST) INF 0.19
8 * 4.608 1.61 1.49707 81.5
9 * -1.583 0.10
10 * 11.574 0.51 1.63414 23.8
11 * 1.456 0.22
12 * 4.561 1.92 1.54537 56.1
13 * -1.771 1.45
14 INF 0.70 1.51680 64.2
15 INF 0.15
image INF

The data of the lens surface of the single focus imaging optical system of Example 7 is shown in Table 21 below.
[Table 21]
Third side
K = 7.158, A3 = 7.3834E-04, A4 = 6.7154E-03, A5 = 2.0825E-04,
A6 = -1.4309E-03, A7 = 1.6688E-05, A8 = 3.7828E-04, A10 = -1.1705E-04,
A12 = 2.5776E-05, A14 = -3.5417E-06, A16 = 2.9006E-07, A18 = -1.2982E-08,
A20 = 2.4376E-10
4th side
K = -0.698, A3 = -2.456E-02, A4 = 1.7165E-02, A5 = -2.1175E-02,
A6 = 6.9920E-02, A7 = 3.4129E-03, A8 = -1.4319E-01, A10 = 1.7501E-01,
A12 = -1.2757E-01, A14 = 5.6617E-02, A16 = -1.5083E-02, A18 = 2.2492E-03,
A20 = -1.4706E-04
Side 5
K = -7.053, A3 = 1.6840E-02, A4 = -1.2165E-02, A5 = 1.3055E-02,
A6 = 8.1724E-03, A7 = -5.5198E-03, A8 = -2.2639E-03, A10 = 1.4295E-03,
A12 = 1.7306E-04, A14 = -1.0871E-04, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.5247E-02, A4 = -2.9329E-02, A5 = 3.8947E-02,
A6 = 1.4564E-02, A7 = -2.5513E-02, A8 = 2.8903E-03, A10 = 6.4435E-03,
A12 = 6.7087E-03, A14 = -1.3860E-02, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = 6.087, A3 = 0.000E + 00, A4 = -1.5232E-02, A5 = 0.000E + 00,
A6 = -9.0436E-03, A7 = 0.000E + 00, A8 = 9.5526E-03, A10 = -2.4041E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -1.982, A3 = 0.000E + 00, A4 = -3.9632E-02, A5 = 0.000E + 00,
A6 = 3.2304E-02, A7 = 0.000E + 00, A8 = -2.4628E-02, A10 = 6.7747E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = 49.657, A3 = -8.2791E-03, A4 = -1.8283E-01, A5 = -2.5925E-02,
A6 = 1.5079E-01, A7 = 5.0445E-03, A8 = -7.4581E-02, A10 = 2.0868E-02,
A12 = -2.3734E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -5.465, A3 = 3.3463E-03, A4 = -3.5408E-02, A5 = -6.0857E-03,
A6 = 2.3687E-02, A7 = 1.0441E-03, A8 = -5.9928E-03, A10 = 1.6147E-04,
A12 = 2.6892E-04, A14 = -4.3189E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.539, A3 = -1.9652E-03, A4 = 2.7659E-02, A5 = 1.4953E-03,
A6 = -2.7396E-02, A7 = -3.1694E-04, A8 = 1.2428E-02, A10 = -3.1115E-03,
A12 = 4.0456E-04, A14 = -2.0988E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.702, A3 = 2.4906E-02, A4 = -1.7199E-02, A5 = 4.5703E-03,
A6 = 2.5241E-03, A7 = -5.3121E-04, A8 = 1.5726E-03, A10 = -8.7597E-04,
A12 = 2.4187E-04, A14 = -2.3913E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 8A is a cross-sectional view of the single focus imaging optical system 10G and the like according to the seventh embodiment. Specifically, in the single focus imaging optical system 10G, the negative first lens L1, the negative second lens L2, the positive third lens L3, the aperture (or aperture aperture) ST, and the positive first lens are arranged in this order from the object side. It is substantially composed of a 4-lens L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

8B and 8C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10G of Example 7.

In the single focus imaging optical system 10G of Example 7, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is −0.009 mm.

(Example 8)
The overall specifications of the single focus imaging optical system of Example 8 are shown in Table 22 below.
[Table 22]
f (mm) 1.24
Fno 2.0
w (°) 110.0
ymax (mm) 2.65
TL (mm) 16.56
BF (mm) 2.13

The data of the lens surface of the single focus imaging optical system of Example 8 is shown in Table 23 below.
[Table 23]
Surf.NR (mm) d (mm) nd νd
1 13.418 1.32 1.80422 46.5
2 4.702 3.19
3 * -12.487 0.72 1.54537 56.1
4 * 1.162 1.32
5 * 2.749 2.70 1.63414 23.8
6 * -100.000 0.17
7 (ST) INF 0.19
8 * 3.798 1.65 1.49707 81.5
9 * -1.816 0.10
10 * 20.577 0.50 1.63414 23.8
11 * 1.784 0.19
12 * 4.634 2.15 1.54537 56.1
13 * -2.444 1.44
14 INF 0.70 1.51680 64.2
15 INF 0.23
image INF

The data of the lens surface of the single focus imaging optical system of Example 8 is shown in Table 24 below.
[Table 24]
Third side
K = 7.017, A3 = 5.7919E-04, A4 = 6.7082E-03, A5 = 2.1047E-04,
A6 = -1.4269E-03, A7 = 1.7778E-05, A8 = 3.7834E-04, A10 = -1.1698E-04,
A12 = 2.5788E-05, A14 = -3.5416E-06, A16 = 2.8993E-07, A18 = -1.3000E-08,
A20 = 2.4611E-10
4th side
K = -0.713, A3 = -3.5889E-02, A4 = 1.4728E-02, A5 = -2.3360E-02,
A6 = 6.8572E-02, A7 = 2.6735E-03, A8 = -1.4350E-01, A10 = 1.7502E-01,
A12 = -1.2755E-01, A14 = 5.6620E-02, A16 = -1.5084E-02, A18 = 2.2485E-03,
A20 = -1.4695E-04
Side 5
K = -3.774, A3 = 1.0295E-02, A4 = -9.7277E-03, A5 = 1.3521E-02,
A6 = 7.2958E-03, A7 = -6.0377E-03, A8 = -2.4540E-03, A10 = 1.3919E-03,
A12 = 1.3304E-04, A14 = -7.5736E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.1510E-02, A4 = -3.4966E-02, A5 = 3.6406E-02,
A6 = 1.3446E-02, A7 = -2.9067E-02, A8 = 6.3956E-03, A10 = 3.6388E-03,
A12 = 8.2252E-03, A14 = -5.5157E-03, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = 3.959, A3 = 0.000E + 00, A4 = -1.4884E-02, A5 = 0.000E + 00,
A6 = 1.8110E-03, A7 = 0.000E + 00, A8 = 2.3045E-03, A10 = -1.1241E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -1.398, A3 = 0.000E + 00, A4 = -4.2153E-02, A5 = 0.000E + 00,
A6 = 4.4877E-02, A7 = 0.000E + 00, A8 = -2.5818E-02, A10 = 6.2878E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = 7.820, A3 = 1.2785E-02, A4 = -1.8787E-01, A5 = -3.2084E-02,
A6 = 1.4737E-01, A7 = 1.9645E-03, A8 = -7.5871E-02, A10 = 2.1014E-02,
A12 = -2.0402E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -4.916, A3 = 8.4659E-05, A4 = -3.6431E-02, A5 = -7.2906E-03,
A6 = 2.3027E-02, A7 = 9.030E-04, A8 = -5.9835E-03, A10 = 1.4559E-04,
A12 = 2.4641E-04, A14 = -3.8138E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.018, A3 = -2.3330E-03, A4 = 2.6362E-02, A5 = 9.9768E-04,
A6 = -2.7589E-02, A7 = -1.7034E-04, A8 = 1.2436E-02, A10 = -3.0927E-03,
A12 = 4.1095E-04, A14 = -2.2867E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.594, A3 = 1.2997E-02, A4 = -1.8900E-02, A5 = 3.1613E-03,
A6 = 1.7400E-03, A7 = -8.7963E-04, A8 = 1.4297E-03, A10 = -8.9773E-04,
A12 = 2.4196E-04, A14 = -2.0355E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 9A is a cross-sectional view of the single focus imaging optical system 10H and the like according to the eighth embodiment. Specifically, the single focus imaging optical system 10H has a negative first lens L1, a negative second lens L2, a positive third lens L3, an aperture (or aperture aperture) ST, and a positive first lens in order from the object side. It consists substantially of four lenses L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

9B and 9C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10H of Example 8.

In the single focus imaging optical system 10H of Example 8, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is −0.010 mm.

(Example 9)
The overall specifications of the single focus imaging optical system of Example 9 are shown in Table 25 below.
[Table 25]
f (mm) 1.33
Fno 2.0
w (°) 110.0
ymax (mm) 2.65
TL (mm) 15.98
BF (mm) 2.16

The data of the lens surface of the single focus imaging optical system of Example 9 is shown in Table 26 below.
[Table 26]
Surf.NR (mm) d (mm) nd νd
1 14.041 1.40 1.80422 46.5
2 4.133 2.68
3 * -13.451 0.72 1.54537 56.1
4 * 1.563 1.36
5 * 3.498 2.70 1.63414 23.8
6 * -9.793 0.24
7 (ST) INF 0.19
8 * 4.602 1.51 1.49707 81.5
9 * -1.611 0.10
10 * 18.420 0.50 1.63414 23.8
11 * 1.358 0.23
12 * 4.622 1.94 1.54537 56.1
13 * -2.200 1.49
14 INF 0.70 1.51680 64.2
15 INF 0.21
image INF

The data of the lens surface of the single focus imaging optical system of Example 9 is shown in Table 27 below.
[Table 27]
Third side
K = 6.221, A3 = 7.3013E-04, A4 = 6.7925E-03, A5 = 2.3405E-04,
A6 = -1.4211E-03, A7 = 1.9111E-05, A8 = 3.7838E-04, A10 = -1.1718E-04,
A12 = 2.5769E-05, A14 = -3.5421E-06, A16 = 2.9008E-07, A18 = -1.2979E-08,
A20 = 2.4388E-10
4th side
K = -0.658, A3 = -5.2209E-03, A4 = 2.0854E-02, A5 = -2.0642E-02,
A6 = 6.9791E-02, A7 = 3.1455E-03, A8 = -1.4333E-01, A10 = 1.7499E-01,
A12 = -1.2758E-01, A14 = 5.6613E-02, A16 = -1.5085E-02, A18 = 2.2487E-03,
A20 = -1.4685E-04
Side 5
K = -5.620, A3 = 1.5442E-02, A4 = -1.2406E-02, A5 = 1.1971E-02,
A6 = 7.0014E-03, A7 = -6.3827E-03, A8 = -2.7543E-03, A10 = 1.3501E-03,
A12 = 1.7973E-04, A14 = -9.3478E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 6
K = 50.000, A3 = 1.0652E-02, A4 = -3.4728E-02, A5 = 3.2590E-02,
A6 = 9.5929E-03, A7 = -2.9992E-02, A8 = 1.0113E-02, A10 = 7.6351E-03,
A12 = -4.7981E-03, A14 = 1.2353E-03, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
8th page
K = 3.488, A3 = 0.000E + 00, A4 = -1.5265E-02, A5 = 0.000E + 00,
A6 = -4.9879E-03, A7 = 0.000E + 00, A8 = 1.5319E-03, A10 = -5.6578E-04,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 9
K = -2.914, A3 = 0.000E + 00, A4 = -3.3676E-02, A5 = 0.000E + 00,
A6 = 3.7133E-02, A7 = 0.000E + 00, A8 = -2.5632E-02, A10 = 6.2236E-03,
A12 = 0.000E + 00, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Side 10
K = 19.602, A3 = -5.9653E-03, A4 = -1.8697E-01, A5 = -2.6983E-02,
A6 = 1.5132E-01, A7 = 4.5507E-03, A8 = -7.4239E-02, A10 = 2.1448E-02,
A12 = -2.4878E-03, A14 = 0.000E + 00, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 11
K = -5.322, A3 = -2.0360E-04, A4 = -3.7114E-02, A5 = -6.9115E-03,
A6 = 2.3592E-02, A7 = 1.2559E-03, A8 = -5.8416E-03, A10 = 1.6498E-04,
A12 = 2.4463E-04, A14 = -4.1757E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
12th page
K = 2.101, A3 = -4.1546E-03, A4 = 2.6090E-02, A5 = 1.0482E-03,
A6 = -2.7428E-02, A7 = -4.9701E-05, A8 = 1.2484E-02, A10 = -3.1061E-03,
A12 = 4.0373E-04, A14 = -2.1326E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00
Page 13
K = -1.415, A3 = 1.2862E-02, A4 = -1.9037E-02, A5 = 3.7960E-03,
A6 = 2.1670E-03, A7 = -6.8386E-04, A8 = 1.5108E-03, A10 = -8.8421E-04,
A12 = 2.4270E-04, A14 = -2.1598E-05, A16 = 0.000E + 00, A18 = 0.000E + 00,
A20 = 0.000E + 00

FIG. 10A is a cross-sectional view of the single focus imaging optical system 10I and the like according to the ninth embodiment. Specifically, the single focus imaging optical system 10I has a negative first lens L1, a negative second lens L2, a positive third lens L3, an aperture (or aperture aperture) ST, and a positive first lens in order from the object side. It consists substantially of four lenses L4, a negative fifth lens L5, and a positive sixth lens L6. Here, the first and fourth lenses L1 and L4 are made of glass, and the second, third, fifth, and sixth lenses L2, L3, L5, and L6 are made of plastic. A parallel flat plate F having an appropriate thickness is arranged between the sixth lens L6 and the solid-state image sensor 51.

10B and 10C show longitudinal aberration diagrams (spherical aberration and astigmatism) of the single focus imaging optical system 10I of Example 9.

In the single focus imaging optical system 10I of Example 9, the amount of focus movement (normal temperature) due to a temperature change of the plastic lenses (specifically, the second, third, fifth, and sixth lenses L2, L3, L5, L6). The amount of movement when the temperature changes from (25 ° C.) to 105 ° C.) is −0.012 mm.

Table 28 below summarizes the values of Examples 1 to 9 corresponding to the conditional expressions (1) to (10) for reference.
[Table 28]

Although the single focus imaging optical system according to the embodiment has been described above, the single focus imaging optical system according to the present invention is not limited to the above-exemplified one. For example, in the above embodiment, a lens or the like having substantially no refractive power can be added between the first to sixth lenses L1 to L6, or on the image side or the object side thereof.

Further, in the above-described embodiment, regarding the parallel plate F, the filter which is a parallel plate is divided into two and separated when imaging with visible light or near-infrared light in applications such as in-vehicle cameras and surveillance cameras. It can also be configured to have the role of.

Claims (14)

From the object side,
The first lens with negative refractive power and
The second lens with both concave shapes and
With a biconvex third lens
Aperture and
A fourth lens with positive refractive power,
A negative fifth lens whose side surface is convex in the paraxial region,
A sixth lens with positive refractive power,
A single focus imaging optical system that becomes practical from. The single focus imaging optical system according to claim 1, which satisfies the following conditional expression.
0.1 <(d34 / f) / (tan (w / 2)) <0.8 ... (1)
d34: Distance between the third lens and the fourth lens f: Focal length w of the entire system: Maximum half angle of view The single focus imaging optical system according to any one of claims 1 and 2, which satisfies the following conditional expression.
-3 ≤ f2 / f ≤ -1 ... (2)
f2: Focal length of the second lens f: Focal length of the whole system The single focus imaging optical system according to any one of claims 1 to 3, which satisfies the following conditional expression.
3 ≦ f3 / f ≦ 6… (3)
f3: Focal length of the third lens f: Focal length of the whole system The single focus imaging optical system according to any one of claims 1 to 4, which satisfies the following conditional expression.
-3 ≤ f5 / f ≤ -1 ... (4)
f5: Focal length of the fifth lens f: Focal length of the whole system The single focus imaging optical system according to any one of claims 1 to 5, which satisfies the following conditional expression.
2 ≦ f1 / f2 ≦ 5.5… (5)
f1: Focal length of the first lens f2: Focal length of the second lens The single focus imaging optical system according to any one of claims 1 to 6, which satisfies the following conditional expression.
-8 ≤ f1 / f ≤ -5 ... (6)
f1: Focal length of the first lens f: Focal length of the whole system The single focus imaging optical system according to any one of claims 1 to 7, which satisfies the following conditional expression.
1.5 ≤ f4 / f ≤ 3 ... (7)
f4: Focal length of the fourth lens f: Focal length of the whole system The single focus imaging optical system according to any one of claims 1 to 8, wherein the second, third, fifth, and sixth lenses are made of plastic and satisfy the following conditional expression.
−0.4 ≦ f × Σ (1 / fplk) ≦ −0.2… (8)
fplk: Focal length of the kth plastic lens from the object side f: Focal length of the whole system The single focus imaging optical system according to any one of claims 1 to 9, which satisfies the following conditional expression.
νL4 ≧ 65… (9)
νL4: Abbe number of the fourth lens The single focus imaging optical system according to any one of claims 1 to 10, which satisfies the following conditional expression.
1.8 ≤ nL1 ... (10)
nL1: Refractive index of the first lens The single focus imaging optical system according to any one of claims 1 to 11.
A lens barrel that holds the single focus imaging optical system and
Lens unit equipped with. The single focus imaging optical system according to any one of claims 1 to 11.
An image sensor that detects an image obtained from the single focus image pickup optical system,
An imaging device comprising. The imaging device according to claim 13, further comprising a lens barrel that holds the single focus imaging optical system.

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