JP3493975B2 - Imaging equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing device. More specifically, the present invention relates to a photographing device that is suitable for a camera including a solid-state image sensor and that includes a compact photographing optical system.

[0002]

2. Description of the Related Art A solid-state image sensor (eg CCD (Ch
A camera (for example, a video camera or a television camera) that receives light by using a large coupled device) and shoots a subject has a micro-focusing device on the incident surface side of each light-receiving element in order to increase the light-receiving efficiency of each light-receiving element. A lens is provided. In order to improve the light condensing property by the microlens, the conventional photographing optical system is configured so that the exit pupil is located at approximately infinity (that is, substantially telecentric on the image side). When the exit pupil is located at approximately infinity, the off-axis light flux enters the microlens from a direction substantially perpendicular to the incident surface of each light receiving element, so that the light converging property by the microlens is improved. .

[0003]

Recently, a photographic optical system having a short total length has been demanded in order to miniaturize a camera. However, when the total length of the photographic optical system is shortened, the position of the exit pupil of the photographic optical system becomes an image. It approaches the face. When the exit pupil position of the photographing optical system approaches the image plane, the off-axis light beam enters the microlenses located in the peripheral portion of the image from the oblique direction with respect to the incident surface of the light receiving element. As a result, the light condensing property of the microlenses is reduced in the peripheral portion of the image, and the brightness of the image differs between the central portion and the peripheral portion of the image captured by the solid-state image sensor. As described above, in the conventional photographing optical system, there is a problem that it is impossible to achieve both the positioning of the exit pupil of the photographing optical system at approximately infinity and the reduction of the total length of the photographing optical system. is there.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a photographing apparatus provided with a photographing optical system whose exit pupil is located at substantially infinity and whose total length is short. To do.

[0005]

To achieve the above object, according to the Invention The photographing apparatus of the first invention includes an imaging optical system, a light beam emitted from the imaging optical system a plurality of light receiving elements are arranged A solid-state image pickup device is an image pickup apparatus that receives an image of an object as electrical image data, and the image pickup optical system includes, in order from the object side, a first lens group having negative power and a first lens group having positive power. Two lens groups, a third lens group having negative power, a fourth lens group having positive power,
A capacitor over a lens having a positive power, consists of five components, each lens group interval and the fourth lens unit capacitor
Line zooming by changing the distance between the over lens
It is characterized by satisfying the following conditions . 1.0 <φ 4 / φ C < 5.0 , where φ 4 is the power of the fourth lens group, and φ C is the power of the condenser lens . A photographing apparatus according to a second invention is the same as that according to the first invention.
The main optical system is composed of the four components of the first to fourth lens groups.
It is characterized by satisfying the following conditions. 0.5 < LBW / Y'max < 2.0 where LBW is the back focus of the main optical system at the wide-angle end, and Y'max is the maximum image height . According to a third aspect of the present invention, there is provided an image pickup apparatus,
In the invention, the photographing optical system is a low-pass filter in the optical path.
It is characterized in that a filter is arranged.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A video taking optical system embodying the present invention will be described below with reference to the drawings. 1 to 4
[Fig. 6] is a lens configuration diagram corresponding to each of the image pickup optical systems according to the first to fourth embodiments, showing a lens arrangement at a wide-angle end [W]. The arrows mi (i = 1,
2, 3, ...) schematically show the movement of the i-th lens group (Gri) during zooming from the wide-angle end [W] to the telephoto end [T]. Also, in each lens configuration diagram, ri (i = 1,2,
The surface marked with (3, ...) is the i-th surface counted from the object side, and the surface marked with * in ri is an aspherical surface. di (i = 1,2,
The axial upper surface spacing between the lens groups denoted by (3, ...) Is a variable spacing that changes during zooming among the i-th axial upper surface spacing counted from the object side.

The first to fourth embodiments are video taking optical systems used for forming an image of an object on a solid-state image pickup device (not shown). Main optical system ML with power and low-pass filter LP
And a condenser lens CL having a positive power. The main optical system ML comprises, in order from the object side, a first lens group Gr1 having negative power, a second lens group Gr2 having positive power, and a third lens group having negative power.
The lens group Gr3 and the fourth lens group G having a positive power
r4 and four zoom groups, and the low-pass filter LP and the condenser lens CL form a fifth lens group Gr5 having a positive power.

The main optical system ML has a four-component zoom (negative / positive / negative).
Although it has a single optical performance (negative / positive), it has a fixed low-pass filter LP and a condenser lens CL in the final lens group (the fifth lens group Gr5) in zooming.
As a whole, the taking optical system is the main part of the 5-component zoom (negative / positive / negative / positive / positive). Further, the condenser lens CL arranged near the image plane between the main optical system ML and the solid-state image sensor acts so that the positive pupil of the condenser lens CL positions the exit pupil of the photographing optical system at approximately infinity.

Zooming is performed by changing the distance between the lens groups. Since the fifth lens group Gr5 is a fixed group, the fourth lens group Gr4 and the condenser lens CL
The interval between and also changes naturally. In the first and second embodiments, the zoom movement is performed together with the second lens group Gr2 between the most object side surface of the second lens group Gr2 and the most image side surface of the first lens group Gr1. A light-shielding plate (flare cutter) S is provided to prevent the surface of the second lens group Gr2 closest to the image side and the surface of the third lens group Gr3 closest to the object side from each other in the first to fourth embodiments. In between, the third lens group G
A diaphragm A that zooms with r3 is arranged.

In the first embodiment, the main optical system ML
The respective lens groups constituting the above are sequentially configured from the object side as follows. The first lens group Gr1 includes a biconvex positive lens, a negative meniscus lens having a concave surface facing the image side, and
A positive meniscus lens with a convex surface facing the image side, a biconcave negative lens, and a positive meniscus lens with a convex surface facing the object side,
It is composed of. The second lens group Gr2 is composed of a biconvex positive cemented lens, a positive cemented meniscus lens having a convex surface facing the object side, and a positive meniscus lens having a convex surface facing the object side. The third lens group Gr3 is composed of a biconcave cemented lens and a negative meniscus lens having a concave surface facing the object side. The fourth lens group Gr4 includes a negative meniscus lens having a concave surface facing the image side, a biconvex positive lens, and a positive cemented meniscus lens having a convex surface facing the object side. Also, condenser lens CL
Is a plano-convex lens with a convex surface facing the image side.

In the second embodiment, the main optical system ML
The respective lens groups constituting the above are sequentially configured from the object side as follows. The first lens group Gr1 includes a biconcave negative lens, a negative meniscus lens having a concave surface facing the image side, and
A positive meniscus lens with a convex surface facing the image side, a biconcave negative lens, and a positive meniscus lens with a convex surface facing the object side,
It is composed of. The second lens group Gr2 is composed of a biconvex positive cemented lens, a positive cemented meniscus lens having a convex surface facing the object side, and a positive meniscus lens having a convex surface facing the object side. The third lens group Gr3 is composed of a negative cemented meniscus lens having a concave surface facing the image side and a negative meniscus lens having a concave surface facing the object side.
The fourth lens group Gr4 includes a negative meniscus lens having a concave surface facing the image side, a biconvex positive lens, and a positive cemented meniscus lens having a convex surface facing the object side. The condenser lens CL is a plano-convex lens with a convex surface facing the image side.

In the third embodiment, the main optical system ML
The respective lens groups constituting the above are sequentially configured from the object side as follows. The first lens group Gr1 includes three negative meniscus lenses having a concave surface facing the image side and a positive meniscus lens having a convex surface facing the object side. Second
The lens group Gr2 is composed of a biconvex positive cemented lens and a positive meniscus lens having a convex surface directed toward the object side. The third lens group Gr3 is composed of a biconcave negative cemented lens. The fourth lens group Gr4 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and a biconcave negative lens. The condenser lens CL is a plano-convex lens with a convex surface facing the image side.

In the fourth embodiment, the main optical system ML
The respective lens groups constituting the above are sequentially configured from the object side as follows. The first lens group Gr1 is composed of two negative meniscus lenses having a concave surface facing the image side and a positive meniscus lens having a convex surface facing the object side. Second
The lens group Gr2 is composed of a biconvex positive cemented lens and a negative meniscus lens having a concave surface facing the image side.
The third lens group Gr3 is composed of a biconcave negative cemented lens. The fourth lens group Gr4 includes two biconvex positive lenses and a biconcave negative lens. The condenser lens CL is a plano-convex lens with a convex surface facing the image side.

As described above, in a camera equipped with a solid-state image sensor, it is desirable that a light ray be incident vertically on the incident surface of the solid-state image sensor. For that purpose, the exit pupil position of the photographing optical system is set to the image plane. It is desirable to keep it away from In each of the above embodiments, the condenser lens CL arranged near the image plane between the main optical system ML and the solid-state image sensor.
As described above, the positive power acts so that the exit pupil of the photographing optical system is located at approximately infinity. By the action of the condenser lens CL, the exit pupil position of the photographing optical system can be moved away from the image plane, so that the total length of the photographing optical system can be shortened. In addition, as compared with the case where the condenser lens CL is not arranged, the exit pupil position of the photographing optical system can be moved away from the image plane with almost no loss in the image forming performance of the main optical system ML.

In the negative / positive / negative / positive four-component zoom, the exit pupil position of the photographing optical system is determined mainly by the power strength of the first lens group Gr1. Therefore, the power of the condenser lens CL may be appropriately set according to the exit pupil position of the main optical system ML. For example, the stronger the power of the condenser lens CL is, the stronger the action of moving the exit pupil position of the photographing optical system away is. Therefore, the closer the exit pupil position of the main optical system ML is to the image plane, the stronger the power of the condenser lens CL is. Good. Conversely, condenser lens C
Since the weaker the power of L is, the weaker the action of moving the exit pupil position of the photographing optical system is, the power of the condenser lens CL may be weaker as the exit pupil position of the main optical system ML is farther from the image plane.

Since the main optical system ML is a zoom lens, the exit pupil position moves in the optical axis AX direction with zooming. Therefore, it is desirable to balance the exit pupil position at the wide-angle end [W] and the exit pupil position at the telephoto end [T]. If this balance is not achieved, the exit pupil position is the solid-state image sensor on either side. No match. In order to achieve this balance, at least one of the following conditional expressions (1) to (4) that defines the relationship between the exit pupil position of the main optical system ML and the power of the condenser lens CL must be satisfied. desirable.

As in each of the embodiments, in the five-component zoom lens formed by adding the condenser lens CL to the rear of the main optical system ML consisting of four components of negative, positive, negative and positive,
It is desirable to satisfy the following conditional expression (1). -5.5 <φ1 / φC <-0.4 (1) where φ1 is the power of the first lens group (Gr1) and φC is the power of the condenser lens (CL).

If the lower limit of conditional expression (1) is exceeded, the first lens group G
When the negative power of r1 becomes strong, the back focus becomes long and the exit pupil position of the main optical system ML moves away from the image plane, but at the same time, the height of the incident light on the lenses after the second lens group Gr2 becomes high, It becomes difficult to correct the aberration of the main optical system ML. In particular, excessive positive distortion and spherical aberration will occur. On the contrary, when the negative power of the first lens group Gr1 becomes weaker than the upper limit of the conditional expression (1), the height of incident light on the lenses after the second lens group Gr2 becomes low, so that distortion and spherical aberration However, since the exit pupil position approaches the image plane, it becomes necessary to increase the power of the condenser lens CL. When the power of the condenser lens CL is increased, the condenser lens C
Aberration occurs at L, and in particular, the Petzval sum increases, so that the difference in the image plane increases and correction becomes impossible.

As in each of the embodiments, in the five-component zoom lens formed by adding the condenser lens CL to the rear of the main optical system ML consisting of four components of negative, positive, negative and positive,
It is desirable to satisfy the following conditional expression (2). 0.5 <φ2 / φC <7.0 (2) where φ2 is the power of the second lens group (Gr2) and φC is the power of the condenser lens (CL).

If the upper limit of conditional expression (2) is exceeded, the second lens group G
When the positive power of r2 becomes strong, the distance from the negative first lens group Gr1 on the wide-angle side increases, so that the proportion of the negative-positive retrofocus type becomes strong as a whole, and the back focus can be obtained. Therefore, although it is advantageous in moving the exit pupil position away from the image plane, there is a problem that the photographing optical system becomes large. On the contrary, when the positive power of the second lens group Gr2 becomes weaker than the lower limit of the conditional expression (2), the retro focus type cannot be obtained.
The back focus becomes shorter. Therefore, it is necessary to increase the power of the condenser lens CL in order to move the exit pupil position away from the image plane.
If the power of L is too strong, the positive power of the entire shooting optical system will be strong, and the Petzval sum will be large, making it impossible to maintain the image plane property.

As in each of the embodiments, in the five-component zoom lens formed by adding the condenser lens CL to the rear of the main optical system ML consisting of four components of negative, positive, negative and positive,
It is desirable to satisfy the following conditional expression (3). -7.0 <φ3 / φC <-0.5 (3) where φ3 is the power of the third lens group (Gr3) and φC is the power of the condenser lens (CL).

If the lower limit of conditional expression (3) is exceeded, the third lens group G
When the negative power of r3 becomes strong, the entire photographic optical system becomes a telephoto type and becomes compact, but the back focus becomes short and the exit pupil position approaches the image plane. Therefore, it becomes necessary to increase the power of the condenser lens CL, but if the power of the condenser lens CL is too strong, aberration will occur in the condenser lens CL.
In particular, an excessive positive distortion aberration occurs and the Petzval sum increases, so that the difference in the image plane increases, which makes it difficult to correct the aberration. On the contrary, when the negative power of the third lens group Gr3 becomes weaker than the upper limit of the conditional expression (3), the back focus becomes long and the exit pupil position of the main optical system ML moves away from the image plane. Although it is advantageous for the image pickup device, the merit of compactness is lost because the entire photographing optical system becomes large.

As in each of the embodiments, in the five-component zoom lens formed by adding the condenser lens CL to the rear of the main optical system ML composed of four components of negative, positive, negative and positive,
It is desirable to satisfy the following conditional expression (4). 1.0 <φ4 / φC <5.0 (4) where φ4 is the power of the fourth lens group (Gr4) and φC is the power of the condenser lens (CL).

Conditional expression (4) defines the ratio of the power of the fourth lens group Gr4 to the power of the condenser lens CL. When the value goes below the lower limit of conditional expression (4), the positive power of the fourth lens group Gr4 becomes too weak as compared with the condenser lens CL, so that the back focus becomes larger than necessary and a compact zoom lens is achieved. Can't do it. On the contrary, when the upper limit of the conditional expression (4) is exceeded, the positive power of the fourth lens group Gr4 becomes too strong as compared with the condenser lens CL, and the back focus becomes too short. In this case, the telecentricity cannot be maintained unless the power of the condenser lens CL is relatively increased. Therefore, the power of the condenser lens CL must be increased, and as a result, the aberration generated in the condenser lens CL becomes large.

Further, other desirable conditions will be described. As in each embodiment, in the five-component zoom lens in which the condenser lens CL is added to the rear of the main optical system ML including four components of negative, positive, negative and positive, the following conditional expression (5)
It is desirable to satisfy. 0.5 <LBW / Y'max <2.0 (5) However, LBW: Back focus of the main optical system (ML) at the wide-angle end [W], Y'max: Maximum image height.

The conditional expression (5) is the wide-angle end [W] of the main optical system ML.
It defines the relationship between the back focus at the position where the image side surface of the main optical system ML is closest to the image surface and the size of the solid-state image sensor. If the back focus becomes longer than the upper limit of conditional expression (5), the total length of the photographing optical system becomes large, which is not practical. Conversely, if the back focus becomes shorter than the lower limit of conditional expression (5), the low-pass filter LP
It becomes difficult to arrange such optical elements.

As in the respective embodiments, in the five-component zoom lens formed by adding the condenser lens CL to the rear of the main optical system ML composed of four components of negative, positive, negative and positive,
It is desirable to satisfy the following conditional expression (6). 1.2 <bw / aw <3.0 (6) where aw: distance from the exit pupil position of the main optical system (ML) to the image plane at the wide-angle end [W], bw: shooting optics at the wide-angle end [W] It is the distance from the exit pupil position of the system to the image plane.

Conditional expression (6) is defined by the exit pupil position of the main optical system ML (not including the condenser lens CL) and the photographing optical system.
The distance ratio of the exit pupil position (that is, the entire system including the condenser lens CL) with respect to the image plane is defined, and the distance ratio represents the degree of action of the condenser lens CL that moves the exit pupil position away. ing. If the lower limit of conditional expression (6) is exceeded, the exit pupil position is relatively far from the image plane without providing the condenser lens CL, so that the effect itself of providing the condenser lens CL is small. Further, the fact that the exit pupil position is away from the image plane is equivalent to the large size of the main optical system ML itself, and is not practical as an optical system. When the exit pupil position of the photographing optical system is far from the image plane beyond the upper limit of conditional expression (6), the aberrational load on the condenser lens CL becomes large, and the optical performance deteriorates to an unsatisfactory level. In particular, the positive distortion and the image quality deteriorate.

As in each of the embodiments, in the five-component zoom lens formed by adding the condenser lens CL to the rear of the main optical system ML consisting of four components of negative, positive, negative and positive,
It is preferable that at least one of the conditional expressions (1) to (4) is satisfied and the following conditional expression (7) is satisfied. 0.600 <φ2 / φW <0.900 (7) where φW is the power of the photographing optical system at the wide-angle end [W].

The conditional expression (7), together with the conditional expressions (1) to (4), indicates a condition for keeping the taking optical system optimal. The upper limit of conditional expression (7) is exceeded and the second lens group Gr2 is exceeded.
When the positive power of becomes strong, the back focus can be secured, but the correction becomes difficult because the flare of the light beam on the upper side becomes large. When the power of the second lens group Gr2 becomes weaker than the lower limit of the conditional expression (7), it becomes advantageous for aberration correction, but it becomes difficult to secure the back focus. Particularly, it becomes difficult to secure the back focus on the wide angle side. Therefore, in a photographic optical system that is premised on the use of a solid-state image sensor such as a CCD, it is necessary to dispose a low-pass filter or the like, which makes the configuration difficult.

When any of the above conditional expressions (1) to (4) is satisfied, it is possible to control the aberration generated in the condenser lens CL to some extent by making the condenser lens CL an aspherical surface. . By introducing an aspherical surface into the condenser lens CL, while increasing the power of the condenser lens CL,
It is possible to correct the distortion aberration generated in the condenser lens CL. In this case, the aspherical surface added to the condenser lens CL is preferably an aspherical surface in the direction of weakening the positive power toward the periphery (that is, the direction of loosening the power of the surface). By adding such an aspherical surface, it is possible to correct the negative distortion aberration generated in the condenser lens CL.

The aspherical surface added to the condenser lens CL preferably satisfies the following conditional expression (8). -0.01 <PW ・ (N'-N) ・ {x (y) -x (0)} <0.0 (8) where PW is the power of the aspherical surface, N ': Refraction of the medium on the image side of the aspherical surface Index, N: refractive index of the medium on the object side of the aspherical surface, x (y): shape of the aspherical surface, x (0): shape of the reference spherical surface of the aspherical surface, and x (y), x (0) are It is expressed by the following equations (AS) and (RE), respectively. x (y) ＝ {C0 ・ y ² } / {1 + √ (1-ε ・ C0 ²・ y ² )} + Σ (Ai ・ y ⁱ )… (AS) x (0) ＝ {C0 ・ y ² } / {1 + √ (1-C0 ² · y ² )} (RE) However, in formulas (AS) and (RE), y: height in the direction perpendicular to the optical axis, ε: quadric surface parameter , Ai: aspherical coefficient of degree i.

When the upper limit of conditional expression (8) is exceeded, the aspherical surface is such that the positive power becomes weaker toward the periphery of the aspherical surface, so that distortion cannot be corrected. On the other hand, if the lower limit of conditional expression (8) is exceeded, the distortion will be overcorrected, which is not desirable.

Each of the lens groups constituting the first to fourth embodiments is composed of only a refraction type lens that deflects an incident light beam by refraction, but the invention is not limited to this.
For example, each lens group may be configured by a diffractive lens that deflects an incident light beam by diffraction, a refraction / diffraction hybrid lens that deflects an incident light beam by a combination of diffractive action and refraction action, and the like.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a video-taking optical system embodying the present invention will be described in more detail below with reference to construction data, aberration diagrams, and the like. Examples 1 to 4 given as examples here correspond to the above-described first to fourth embodiments, respectively, and are lens configuration diagrams showing the first to fourth embodiments (FIGS. 1 to 4). ) Indicates the corresponding lens configurations of Examples 1 to 4, respectively.

In the construction data of each example, ri (i = 1,2,3, ...) is the radius of curvature of the i-th surface counted from the object side, di (i = 1,2,3 ,. ..) is the i-th axial upper surface distance counted from the object side, and the axial upper surface distance (variable distance) that changes due to zooming is the wide-angle end [W] to intermediate focal length state [M].
~ Actual surface spacing between lens groups at the telephoto end [T].
Further, Ni (i = 1,2,3, ...) and νi (i = 1,2,3, ...) are the refractive index (N
d) and the Abbe number (νd). Each focal length state [W],
Focal length f and F number of the whole system corresponding to [M] and [T]
FNO is shown along with construction data.

The surface marked with * on the radius of curvature ri is
The surface is defined as an aspherical surface, and is defined by the above-mentioned formula (AS) that represents the surface shape of the aspherical surface. Corresponding values of the aspherical surface data and conditional expression (8) regarding the aspherical surface are shown together with the construction data of each example, and Table 1 shows the corresponding values of the conditional expressions (1) to (7) of each example.

[0038]

[Aspherical surface data of the fourth surface (r4)] ε = 1.0000 A4 = -0.10011 × 10 ^-3 A6 = 0.31421 × 10 ^-6 A8 = -0.24188 × 10 ^-6 A10 = 0.10941 × 10 ^-7 A12 = -0.27866 x 10 ^-9

[Aspherical surface data of the 25th surface (r25)] ε = 1.0000 A4 = 0.26215 × 10 ^-4 A6 = 0.11503 × 10 ^-4 A8 = 0.29046 × 10 ^-5 A10 = -0.49935 × 10 ^-6 A12 = 0.40222 × 10 ^-7

[Aspherical surface data of the 29th surface (r29)] ε = 1.0000 A4 = 0.11456 × 10 ^-3 A6 = -0.71256 × 10 ^-5 A8 = -0.35526 × 10 ^-6 A10 = 0.91826 × 10 ^-7 A12 = -0.91325 x 10 ^-8

[0042]

[Aspherical surface data of the fourth surface (r4)] ε = 1.0000 A4 = -0.18478 × 10 ^-3 A6 = -0.25479 × 10 ^-5 A8 = -0.30428 × 10 ^-6 A10 = 0.17274 × 10 ^-7 A12 = -0.67789 × 10 ^-9

[Aspherical surface data of 25th surface (r25)] ε = 1.0000 A4 = -0.11317 × 10 ^-3 A6 = 0.79756 × 10 ^-5 A8 = 0.33989 × 10 ^-5 A10 = -0.43611 × 10 ^-6 A12 = 0.34170 x 10 ^-7

[Aspherical surface data of the 29th surface (r29)] ε = 1.0000 A4 = 0.17682 × 10 ^-3 A6 = -0.94586 × 10 ^-6 A8 = -0.65417 × 10 ^-6 A10 = 0.22065 × 10 ^-7 A12 = 0.13614 x 10 ^-8

[Aspherical surface data of the 36th surface (r36)] ε = 1.0000 A4 = 0.96016 × 10 ^-2 A6 = -0.10340 × 10 ^-2 A8 = 0.76919 × 10 ^-5 A10 = 0.10775 × 10 ^-5 A12 = 0.36429 × 10 ^-7

[Value corresponding to conditional expression (8) of the 36th surface (r36, Gr5)] y = 0.3300 PW · (N′-N) · {x (y) -x (0)} = − 0.1575 × 10 ^-4 y = 0.6600… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.1192 × 10 ^-3 y = 0.9900… PW ・ (N'-N) ・ {x (y ) -x (0)} =-0.3650 × 10 ^-3 y = 1.3200… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.7437 × 10 ^-3 y = 1.6500… PW・ (N'-N) ・ {x (y) -x (0)} =-0.1159 × 10 ^-2 y = 1.9800… PW ・ (N'-N) ・ {x (y) -x (0)} = -0.1423 × 10 ^-2 y = 2.3100… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.1295 × 10 ^-2 y = 2.6400… PW ・ (N'-N)・ {X (y) -x (0)} =-0.6058 × 10 ^-3 y = 2.9700… PW ・ (N'-N) ・ {x (y) -x (0)} = 0.4529 × 10 ^-3 y = 3.3000… PW ・ (N'-N) ・ {x (y) -x (0)} = 0.7486 × 10
^-3

[0048]

[Aspherical surface data of the second surface (r2)] ε = 1.0000 A4 = -0.19255 × 10 ^-3 A6 = -0.12851 × 10 ^-4 A8 = 0.26328 × 10 ^-6 A10 = -0.60770 × 10 ^-8 A12 = -0.36334 x 10 ^-9

[Aspherical surface data of the 28th surface (r28)] ε = 1.0000 A4 = 0.15312 × 10 ^-1 A6 = -0.14818 × 10 ^-2 A8 = 0.64907 × 10 ^-4

[Value corresponding to conditional expression (8) of the 28th surface (r28, Gr5)] y = 0.3500 PW · (N′-N) · {x (y) -x (0)} = − 0.1722 × 10 ^-3 y = 0.7000… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.1306 × 10 ^-2 y = 1.0500… PW ・ (N'-N) ・ {x (y ) -x (0)} =-0.4025 × 10 ^-2 y = 1.4000… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.8395 × 10 ^-2 y = 1.7500… PW・ (N'-N) ・ {x (y) -x (0)} =-0.1392 × 10 ^-1 y = 2.1000… PW ・ (N'-N) ・ {x (y) -x (0)} = -0.1987 × 10 ^-1 y = 2.4500… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.2611 × 10 ^-1 y = 2.8000… PW ・ (N'-N)・ {X (y) -x (0)} =-0.3439 × 10 ^-1 y = 3.1500… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.5041 × 10 ^-1 y = 3.5000… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.8662 × 10
^-1

[0052]

[Aspherical surface data of the second surface (r2)] ε = 1.0000 A4 = -0.11744 × 10 ^-3 A6 = -0.11084 × 10 ^-4 A8 = 0.13491 × 10 ^-6 A10 = -0.12471 × 10 ^-8 A12 = -0.36737 x 10 ^-9

[Aspherical surface data of the 26th surface (r26)] ε = 1.0000 A4 = 0.13532 × 10 ^-1 A6 = -0.11449 × 10 ^-2 A8 = 0.49295 × 10 ^-4

[Value corresponding to conditional expression (8) of 26th surface (r26, Gr5)] y = 0.3500 PW · (N′-N) · {x (y) -x (0)} = − 0.1526 × 10 ^-3 y = 0.7000… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.1165 × 10 ^-2 y = 1.0500… PW ・ (N'-N) ・ {x (y ) -x (0)} =-0.3636 × 10 ^-2 y = 1.4000… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.7728 × 10 ^-2 y = 1.7500… PW・ (N'-N) ・ {x (y) -x (0)} =-0.1317 × 10 ^-1 y = 2.1000… PW ・ (N'-N) ・ {x (y) -x (0)} = -0.1948 × 10 ^-1 y = 2.4500… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.2662 × 10 ^-1 y = 2.8000… PW ・ (N'-N)・ {X (y) -x (0)} =-0.3593 × 10 ^-1 y = 3.1500… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.5175 × 10 ^-1 y = 3.5000… PW ・ (N'-N) ・ {x (y) -x (0)} =-0.8348 × 10
^-1

[0056]

[Table 1]

5 to 8 are aberration charts corresponding to Examples 1 to 4, respectively, in which [W] is the wide-angle end,
[M] indicates middle, and [T] indicates various aberrations at the telephoto end (in order from left, spherical aberration, astigmatism, distortion; Y ': image height). In each aberration diagram, the solid line (d) is the aberration for the d line,
The broken line (SC) represents the sine condition, and the broken line (DM) and the solid line
(DS) represents the astigmatism on the d-line on the meridional surface and the sagittal surface, respectively.

[0058]

As described above, according to the present invention, the exit pupil position can be moved away from the image plane even if the photographing optical system is downsized. Therefore, it is possible to realize a photographic optical system in which the exit pupil is located at approximately infinity and the overall length is short. By using this photographing optical system, it is possible to suppress a decrease in illuminance from the central portion to the peripheral portion of the image photographed by the solid-state imaging device, and thus it is possible to obtain an image with uniform brightness.

[Brief description of drawings]

FIG. 1 is a lens configuration diagram of a first embodiment (Example 1).

FIG. 2 is a lens configuration diagram of a second embodiment (Example 2).

FIG. 3 is a lens configuration diagram of a third embodiment (Example 3).

FIG. 4 is a lens configuration diagram of a fourth embodiment (Example 4).

FIG. 5 is an aberration diagram of Example 1.

FIG. 6 is an aberration diagram of Example 2.

FIG. 7 is an aberration diagram of Example 3.

FIG. 8 is an aberration diagram of Example 4.

[Explanation of symbols]

Gr1 ... 1st lens group Gr2 ... Second lens group Gr3 ... Third lens group Gr4 ... 4th lens group Gr5 ... Fifth lens group ML ... Main optical system LP: Low-pass filter CL ... Condenser lens S ... Shading plate (flare cutter) A ... Aperture

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-27175 (JP, A) JP-A-63-241511 (JP, A) JP-A-8-86964 (JP, A) JP-A-7- 287168 (JP, A) JP 5-313065 (JP, A) JP 5-173071 (JP, A) JP 7-261083 (JP, A) JP 5-203873 (JP, A) JP-A-6-94996 (JP, A) JP-A-9-21950 (JP, A) JP-B-49-23912 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 9/00-17/08 G02B 21/02-21/04 G02B 25/00-25/04

Claims (3)

(57) [Claims] 1. An image pickup apparatus comprising an image pickup optical system, wherein a light flux emitted from the image pickup optical system is received by a solid-state image pickup element having a plurality of light receiving elements arranged therein, and an object is photographed as electrical image data. The photographing optical system has, in order from the object side, a first lens group having negative power, a second lens group having positive power, a third lens group having negative power, and positive power. Fourth lens group and condenser having positive power
Consists of five components and over the lens, have rows zooming by changing the distance between each lens group interval and the fourth lens group and the condenser over the lens, imaging device and satisfies the following conditions ; 1.0 <φ 4 / φ C <5.0 However, phi 4: the fourth lens unit of the power, phi C: is the power of the condenser lens. 2. The main light is made up of the four components of the first to fourth lens groups.
Manabu system is configured, the photographing apparatus according to claim 1, characterized by satisfying the following condition; 0.5 <LBW / Y'max <2.0 However, LBW: back focus of the main optical system at the wide-angle end, Y 'max: Maximum image height. Wherein the shooting optical system, according to claim 1, characterized in that Ropasufu <br/> filter over to the optical path is arranged also
Is the photographing device described in 2 .