JP2012141600A - Optical system, imaging apparatus, and manufacturing method of optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical system that has an appropriate vibration-proofing function, an imaging apparatus with the optical system, and a manufacturing method of the optical system.SOLUTION: An optical system includes a first lens element A and a second lens element B that can shift so as to include vertical components with respect to an optical axis, respectively, and the second lens element comprises the first lens element and other lens elements, and the first lens element or second lens element is made shift so as to include vertical components with respect to an optical axis to perform image plane correction.

Description

  The present invention relates to an optical system having an anti-vibration function, an imaging device including the optical system, and a method for manufacturing the optical system.

  2. Description of the Related Art Conventionally, an optical system that has an anti-vibration function and is used in an imaging device such as a camera has been proposed (see, for example, Patent Document 1).

JP 2001-249276 A

  However, the conventional optical system having the image stabilization function has a problem that when the image plane correction amount is increased, the lens shift amount is increased and control becomes difficult.

  The present invention has been made in view of such a problem, and an object thereof is to provide an optical system having a suitable anti-vibration function, an imaging apparatus including the optical system, and a method for manufacturing the optical system.

  In order to achieve the above object, an optical system according to the present invention includes a first lens element and a second lens element that can be shifted so as to include a component in a direction perpendicular to the optical axis, respectively. The lens element includes the first lens element and another lens element, and the first lens element or the second lens element is shifted so as to include a component in a direction perpendicular to the optical axis. Correction is performed.

  In addition, an imaging apparatus according to the present invention includes the above optical system.

  An optical system manufacturing method according to the present invention is an optical system manufacturing method having a first lens element and a second lens element, wherein the second lens element is replaced with the first lens element and another lens element. The first lens element and the second lens element are arranged so as to be shiftable so as to include a component in a direction perpendicular to the optical axis, and the image plane correction is performed by the first lens element or the first lens element. One of the two lens elements is configured to be shifted so as to include a component in a direction perpendicular to the optical axis.

  ADVANTAGE OF THE INVENTION According to this invention, the optical system which has a suitable anti-vibration function, the imaging device provided with the said optical system, and the manufacturing method of the said optical system can be provided.

It is a figure which shows the structure of the optical system which concerns on 1st Example of this invention. (A) is an aberration diagram in the wide-angle end state at the time of focusing on infinity of the optical system according to Example 1, and (b), (c), and (d) are respectively in the wide-angle end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A, the lens element B, and the lens element C. (A) is an aberration diagram in the intermediate focal length state at the time of focusing on infinity of the optical system according to the first example. (B), (c), (d) are the intermediate focal lengths, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed by the lens element A, the lens element B, and the lens element C in a state. (A) is an aberration diagram in the telephoto end state at the time of focusing on infinity of the optical system according to Example 1, and (b), (c), and (d) are respectively in the telephoto end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A, the lens element B, and the lens element C. It is a figure which shows the structure of the optical system which concerns on 2nd Example of this invention. (A) is an aberration diagram in the wide-angle end state at the time of focusing on infinity of the optical system according to Example 2, and (b) and (c) are respectively the lens element A and the lens element A in the wide-angle end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. (A) is an aberration diagram in the intermediate focal length state at the time of focusing on infinity of the optical system according to Example 2, and (b) and (c) are lens elements in the intermediate focal length state, respectively. FIG. 6A is a meridional lateral aberration diagram when image blur correction is performed by A and a lens element B; (A) is an aberration diagram in the telephoto end state at the time of focusing on infinity of the optical system according to Example 2, and (b) and (c) are respectively the lens element A and the telephoto end state in the telephoto end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. It is a figure which shows the structure of the optical system which concerns on 3rd Example of this invention. (A) is an aberration diagram in the wide-angle end state at the time of focusing on infinity of the optical system according to Example 3, and (b) and (c) are respectively the lens element A and the lens element A in the wide-angle end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. (A) is an aberration diagram in the intermediate focal length state at the time of focusing on infinity of the optical system according to Example 3, and (b) and (c) are lens elements in the intermediate focal length state, respectively. FIG. 6A is a meridional lateral aberration diagram when image blur correction is performed by A and a lens element B; (A) is an aberration diagram in the telephoto end state at the time of focusing on infinity of the optical system according to Example 3, and (b) and (c) are respectively the lens element A in the telephoto end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. It is a figure which shows the structure of the optical system which concerns on 4th Example of this invention. (A) is an aberration diagram in the wide-angle end state at the time of focusing on infinity of the optical system according to Example 4, and (b), (c), and (d) are respectively in the wide-angle end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A, the lens element B, and the lens element C. (A) is an aberration diagram in the intermediate focal length state at the time of focusing on infinity of the optical system according to Example 4, and (b), (c) and (d) are the intermediate focal lengths, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed by the lens element A, the lens element B, and the lens element C in a state. (A) is an aberration diagram in the telephoto end state at the time of focusing on infinity of the optical system according to Example 4, and (b), (c), and (d) are respectively in the telephoto end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A, the lens element B, and the lens element C. It is a figure which shows the structure of the optical system which concerns on 5th Example of this invention. (A) is an aberration diagram in the wide-angle end state at the time of focusing on infinity of the optical system according to Example 5, and (b) and (c) are respectively the lens element A and the lens element A in the wide-angle end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. (A) is an aberration diagram in the intermediate focal length state at the time of focusing on infinity of the optical system according to Example 5, and (b) and (c) are lens elements in the intermediate focal length state, respectively. FIG. 6A is a meridional lateral aberration diagram when image blur correction is performed by A and a lens element B; (A) is various aberration diagrams in the telephoto end state at the time of focusing on infinity of the optical system according to Example 5, and (b) and (c) are lens elements A, FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. It is a figure which shows the structure of the optical system which concerns on 6th Example of this invention. (A) is an aberration diagram in the wide-angle end state of the optical system according to Example 6 at the time of focusing on infinity, and (b) and (c) are respectively the lens element A in the wide-angle end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. (A) is an aberration diagram in the intermediate focal length state at the time of focusing on infinity of the optical system according to Example 6, and (b) and (c) are lens elements in the intermediate focal length state, respectively. FIG. 6A is a meridional lateral aberration diagram when image blur correction is performed by A and a lens element B; (A) is an aberration diagram in the telephoto end state at the time of focusing on infinity of the optical system according to Example 6, and (b) and (c) are respectively the lens element A in the telephoto end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element B. It is sectional drawing which shows the outline of the digital single-lens reflex camera provided with the optical system of this invention. It is a figure which shows the outline of the manufacturing method of the optical system which concerns on this invention. It is a figure which shows the outline of the manufacturing method of the optical system which concerns on this invention. It is the schematic which shows the example of a structure of the image stabilization function in the optical system which concerns on this invention.

  Hereinafter, an optical system and an imaging apparatus according to the present invention will be described.

  First, the optical system according to the present invention will be described. The optical system according to the present invention is an optical system having an anti-vibration function.

  The optical system according to the present invention includes a first lens element and a second lens element that can be shifted to include a component in a direction perpendicular to the optical axis, and the second lens element includes the first lens element and the second lens element. It consists of other lens elements. Image blur correction is performed by shifting the first lens element or the second lens element so as to include a component in a direction perpendicular to the optical axis, thereby performing image plane correction.

  Here, in this specification, a lens element refers to one unit composed of a single lens or a plurality of lenses.

  The control unit determines which of the first lens element and the second lens element is shifted based on the amount of image blur detected by an angular velocity sensor or the like provided in the imaging apparatus. FIG. 28 is a schematic diagram showing an example of the configuration of the image stabilization function in the optical system according to the present invention. The control unit 21 calculates an image blur correction amount from the angular velocities detected by the plurality of angular velocity sensors 23, 23, that is, the inclination and orientation of the imaging apparatus main body 31, and the lens element according to the correction amount. Decide which of 25a and 25b to shift. Then, the control unit 21 drives the determined lens element (for example, the lens element 25a) via a driving device 27 such as a motor in a direction that cancels the inclination of the imaging device main body 31. The control unit 21 may be provided in the imaging apparatus main body 31 or may be incorporated in the lens barrel 29 in which the optical system is disposed.

  By adopting such a configuration, the optical system of the present invention has an effect of having a plurality of image plane correction functions, and an optical system having a suitable image stabilization function can be realized.

  In the present invention, an optical system having a more suitable image stabilization function can be realized under such a configuration.

  In addition, the optical system according to the present invention includes a first lens element and a second lens element that can be shifted so as to include a component in a direction perpendicular to the optical axis. The lens element and the other lens element have the same refractive power, and the image blur correction is performed by shifting the first lens element or the second lens element so as to include a component perpendicular to the optical axis. Surface correction is performed.

Under such a configuration, an optical system having a more suitable image stabilization function can be realized.
Further, by satisfying the following conditional expression (1), it is possible to realize an optical system having a more suitable vibration-proof function.

(1) | fA |> | fB |
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element However, fA and fB have the same sign as satisfying the conditional expression (1). When the focal length fA of the lens element and the focal length fB of the second lens element have the same sign, the absolute value of the focal length fB of the second lens element is greater than the absolute value of the focal length fA of the first lens element. Therefore, even if the movement amount of the second lens element is the same as that of the first lens element, the image plane movement amount can be increased by shifting the second lens element. As a result, when the second lens element is shifted and image blur is corrected, more images can be obtained without increasing the amount of lens movement than when the first lens element is shifted and image blur is corrected. Blur correction is possible, and large field curvature aberration can be corrected well.

  The optical system according to the present invention preferably satisfies the following conditional expression (2).

(2) 0.24 <| fB | / | fA | <1.00
However,
| FA |: absolute value of the focal length of the first lens element | fB |: absolute value of the focal length of the second lens element where fA and fB have the same sign Conditional Expression (2) It is a conditional expression which prescribes | regulates the focal distance of 1 lens element and 2nd lens element. By satisfying conditional expression (2), when the focal length fA of the first lens element and the focal length fB of the second lens element have the same sign, good optical performance can be realized even during image plane correction. Can do.

  If the corresponding value of the conditional expression (2) is less than the lower limit value, it is not preferable because it becomes difficult to correct coma at the time of image plane correction. In order to secure the effect of the present invention, it is preferable to set the lower limit of conditional expression (2) to 0.30.

  When the corresponding value of the conditional expression (2) exceeds the upper limit value, the focal length of the first lens element that performs image plane correction and the focal length of the second lens element become close, and as a result, a plurality of image plane correction functions are provided. The effect it has is not obtained, which is not preferable. In order to secure the effect of the present invention, it is preferable to set the upper limit of conditional expression (2) to 0.96.

The optical system according to the present invention further includes a third lens element that can be shifted to include a component in a direction perpendicular to the optical axis. The third lens element includes the second lens element and the second lens. The lens element is composed of another lens element having a refracting power having the same sign as the refracting power of the element, and any one of the first lens element, the second lens element, and the third lens element is a component perpendicular to the optical axis. The image is corrected so as to include the image blur. Under such a configuration, an optical system having a more suitable image stabilization function can be realized.
Moreover, it is preferable that the following conditional expression (3) is satisfied.

(3) | fA |> | fB |> | fC |
However,
| FA |: absolute value of the focal length of the first lens element | fB |: absolute value of the focal length of the second lens element | fC |: absolute value of the focal length of the third lens element where fA, fB, and fC The optical system which concerns on this invention can implement | achieve the optical system which has a further more suitable anti-vibration function by such a structure. The control unit determines which of the first lens element, the second lens element, and the third lens element is to be shifted based on the image blur amount detected by the angular velocity sensor or the like, as described with reference to FIG. To do.

  In the present invention, by satisfying the conditional expression (3) under such a configuration, it is possible to realize an optical system having a more suitable anti-vibration function.

  By satisfying conditional expression (3), when the focal length fA of the first lens element, the focal length fB of the second lens element, and the focal length fC of the third lens element have the same sign, Since the absolute value of the focal length fC of the third lens element is smaller than the absolute value of the focal length fB, even if the movement amount of the third lens element is the same as that of the second lens element, the third lens The amount of image plane movement can be increased by shifting the element. As a result, when correcting the image blur by shifting the third lens element, more image blur correction is performed without increasing the amount of movement of the lens than when correcting the image blur by shifting the second lens element. Thus, large curvature of field aberration can be corrected satisfactorily.

  The optical system of the present invention preferably satisfies the following conditional expression (4).

(4) 0.24 <| fC | / | fA | <1.00
However,
| FA |: Absolute value of the focal length of the first lens element | fC |: Absolute value of the focal length of the third lens element where fA and fC have the same sign Conditional expression (4) It is a conditional expression which prescribes | regulates the focal distance of 1 lens element and 3rd lens element. Satisfying conditional expression (4) makes it possible to achieve good optical performance even during image plane correction.

  If the corresponding value of the conditional expression (4) is less than the lower limit value, it is not preferable because it becomes difficult to correct coma at the time of image plane correction. In order to secure the effect of the present invention, it is preferable to set the lower limit of conditional expression (4) to 0.30.

  When the corresponding value of the conditional expression (4) exceeds the upper limit value, the focal lengths of the first lens element, the second lens element, and the third lens element that perform image plane correction become close, and as a result, a plurality of image planes are obtained. An effect having a correction function cannot be obtained, which is not preferable. In order to secure the effect of the present invention, it is preferable to set the upper limit of conditional expression (4) to 0.96.

  In the optical system of the present invention, it is preferable that the first and second lens elements have cemented lenses. With such a configuration, it is possible to maintain good lateral chromatic aberration during image plane correction.

  In the optical system of the present invention, it is preferable that the third lens element has a cemented lens. With such a configuration, it is possible to maintain good lateral chromatic aberration during image plane correction.

  The optical system of the present invention preferably includes at least four lens groups, and at least the first and second lens elements are included in any one of the four lens groups. By adopting such a configuration, coma aberration at the time of image plane correction can be reduced.

  The optical system of the present invention includes a first lens group, a second lens group, a third lens group, and a fourth lens group in order from the object side, and the first lens group and the second lens at the time of zooming. It is preferable that the distance between the groups, the distance between the second lens group and the third lens group, and the distance between the third lens group and the fourth lens group change. By adopting such a configuration, it is possible to realize high zoom ratio and correct spherical aberration satisfactorily.

In addition, the optical system according to the present invention includes a first lens element and a second lens element that can be shifted so as to include a component in a direction perpendicular to the optical axis. The lens element and the other lens element have refracting powers of different signs, and the first lens element or the second lens element is shifted so as to include a component in the direction perpendicular to the optical axis to perform image plane correction. . Under such a configuration, an optical system having a more suitable image stabilization function can be realized.
Moreover, the following conditional expression (5) is satisfied.

(5) | fA | <| fB |
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element However, fA and fB are different from each other. Either the first lens element or the second lens element is shifted. As described with reference to FIG. 28, the control unit determines whether or not to perform this based on the image blur amount detected by the angular velocity sensor or the like.

  With the above-described configuration, the optical system of the present invention has an effect of having a plurality of image plane correction functions, and an optical system having a suitable image stabilization function can be realized.

  In the present invention, a more suitable optical system can be realized by satisfying conditional expression (5) under such a configuration.

  By satisfying conditional expression (5), when fA and fB have different signs, the absolute value of the focal length fA of the first lens element is greater than the absolute value of the focal length fB of the second lens element. Therefore, even if the movement amount of the first lens element is the same as that of the second lens element, the image plane movement amount can be increased by shifting the first lens element. As a result, when correcting the image blur by shifting the first lens element, more image blur correction is performed without increasing the amount of movement of the lens compared to correcting the image blur by shifting the second lens element. Thus, large curvature of field aberration can be corrected satisfactorily.

  The optical system of the present invention preferably satisfies the following conditional expression (6).

(6) 0.24 <| fA | / | fB | <1.00
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element However, fA and fB have different signs. Conditional expression (6) is the first to perform image plane correction. It is a conditional expression that defines the focal length of one lens element and the focal length of a second lens element. By satisfying conditional expression (6), when fA and fB have different signs, good optical performance can be realized even during image plane correction.

  If the corresponding value of conditional expression (6) is less than the lower limit, it is not preferable because it becomes difficult to correct coma during image plane correction. In order to secure the effect of the present invention, it is preferable to set the lower limit of conditional expression (6) to 0.30.

  When the corresponding value of the conditional expression (6) exceeds the upper limit value, the focal length of the first lens element that performs image plane correction and the focal length of the second lens element become close, and as a result, a plurality of image plane correction functions are provided. The effect cannot be obtained, which is not preferable. In order to secure the effect of the present invention, it is preferable to set the upper limit of conditional expression (6) to 0.96.

  In the optical system of the present invention, it is preferable that the first and second lens elements have cemented lenses. With such a configuration, it is possible to maintain good lateral chromatic aberration during image plane correction.

  The optical system of the present invention preferably includes at least four lens groups, and the first and second lens elements are included in any one of the four lens groups. By adopting such a configuration, coma aberration at the time of image plane correction can be reduced.

  The optical system of the present invention includes a first lens group, a second lens group, a third lens group, and a fourth lens group in order from the object side, and the first lens group and the second lens at the time of zooming. It is preferable that the distance between the groups, the distance between the second lens group and the third lens group, and the distance between the third lens group and the fourth lens group change. By adopting such a configuration, it is possible to realize high zoom ratio and correct spherical aberration satisfactorily.

  In addition, an imaging apparatus according to the present invention includes the optical system configured as described above. Thereby, a suitable imaging device can be realized.

  The optical system manufacturing method of the present invention is an optical system manufacturing method having a first lens element and a second lens element, wherein the second lens element is the first lens element and the first lens element. The first lens element and the second lens element can be shifted so as to include a component in the direction perpendicular to the optical axis, respectively. The image plane correction is performed by shifting either the first lens element or the second lens element so as to include a component in a direction perpendicular to the optical axis, and the following conditional expression ( It is characterized by satisfying 1).

(1) | fA |> | fB |
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element where fA and fB have the same sign. A method of manufacturing an optical system having one lens element and a second lens element, wherein the second lens element has a refractive power different from that of the first lens element and the first lens element. The first lens element and the second lens element are arranged so as to be shiftable so as to include a component in a direction perpendicular to the optical axis, and the image plane correction is performed using the first lens element or the second lens element. Any one of the second lens elements is shifted so as to include a component in a direction perpendicular to the optical axis, and the following conditional expression (5) is satisfied. Characterized in that so as to.

(5) | fA | <| fB |
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element However, fA and fB are different from each other. It is preferable depending on the manufacturing method of the optical system of the present invention. It is possible to realize an optical system having a proper vibration isolation function.

(Numerical example)
Hereinafter, an optical system according to numerical examples of the present invention will be described with reference to the accompanying drawings. 1, 5, 9, 13, 17, and 21 are cross-sectional views illustrating the configurations of the optical systems S <b> 1 to S <b> 6 according to each example, and focusing on infinity of these optical systems S <b> 1 to S <b> 6. A change in focus state from the wide-angle end state to the telephoto end state at the time, that is, the movement of each lens group is indicated by an arrow.

(First embodiment)
FIG. 1 is a diagram showing a configuration of an optical system S1 according to the first embodiment of the present invention.

  As shown in FIG. 1, the optical system S1 according to the present embodiment includes, in order from an object side (not shown), a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, The lens unit includes a third lens group G3 having a negative refractive power, an aperture stop SP, and a fourth lens group G4 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a cemented lens L11 of a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side, and a positive meniscus lens having a convex surface facing the object side. L12.

  The second lens group G2, in order from the object side, is a cemented lens L21 of a positive meniscus lens having a convex surface facing the object side and a negative meniscus lens having a convex surface facing the object side, and a positive meniscus lens having a concave surface facing the object side. And a cemented lens L22 of a biconcave negative lens.

  The third lens group G3 includes, in order from the object side, a cemented lens L31 including a positive meniscus lens having a concave surface facing the object side and a negative meniscus lens having a concave surface facing the object side.

  The fourth lens group G4 includes, in order from the object side, a positive meniscus lens L41 having a concave surface directed toward the object side, and a cemented lens L42 of a biconvex positive lens and a negative meniscus lens having a convex surface directed toward the image plane I. , A biconvex positive lens L43, a cemented lens L44 of a positive meniscus lens having a concave surface facing the object side and a biconcave negative lens, a negative meniscus lens L45 having a concave surface facing the object side, and an object side It is composed of a negative meniscus lens L46 having a concave surface and a biconvex positive lens L47.

  On the image plane I, an image sensor (not shown) made up of a CCD, a CMOS, or the like is disposed. The aperture stop SP is disposed between the third lens group G3 and the fourth lens group G4. The configurations of the image sensor and the aperture stop SP are the same in each embodiment described later.

  In the optical system S1 according to the present example, when zooming from the wide-angle end state to the telephoto end state, the first lens group G1 is fixed with respect to the image plane I, and the second lens group G2 is on the image plane I side. The third lens group G3 moves with a substantially concave locus toward the image plane I side, and the fourth lens group is fixed with respect to the image plane I.

  In addition, as shown in FIG. 1, the optical system S1 according to the present embodiment uses the cemented lens L44 in the fourth lens group G4 as a lens element A, and has a refraction having the same sign as the refractive power of the lens element A and the lens element A. The lens element B is composed of the negative meniscus lens L45 having power, and the lens element C is composed of the lens element B and the negative meniscus lens L46 having the same refractive power as that of the lens element B. A, the lens element B, and the lens element C are each set as an anti-vibration lens group. Any one of these anti-vibration lens groups is shifted in a direction perpendicular to the optical axis, thereby preventing blurring of the captured image.

  In the optical system S1 according to the present embodiment, f is the focal length of the entire optical system S1, and K is the ratio of the moving amount of the image on the image plane I to the moving amount of the image stabilizing lens group at the time of blur correction. Sometimes (hereinafter, this ratio is referred to as an anti-vibration coefficient K), in order to correct rotational shake at an angle θ, the lens group for shake correction is set in a direction orthogonal to the optical axis by (f · tan θ) / K. Just shift it.

  The focal lengths f of the entire system in the wide-angle end state, the intermediate focal length, and the telephoto end state of the optical system S1 according to the present embodiment are 95.0 (mm), 163.1 (mm), and 226.6 (mm), respectively. (See Table 1 below). The blur correction amounts by the lens elements A, B, and C and the movement amounts of the lens elements A, B, and C at each focal length are as follows, for example.

  In the optical system S1 according to the present example, in the wide-angle end state, the image stabilization coefficient K when correcting the image blur by the lens element A is 1.26, and the focal length is 95.0 (mm). Therefore, the moving amount of the lens element A for correcting the rotation blur of 0.324 ° is 0.428 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.37 and the focal length is 95.0 (mm), it is necessary to correct the rotational blur of 0.354 °. The moving amount of the lens element B is 0.428 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element C is 1.69 and the focal length is 95.0 (mm), it is necessary to correct the rotation blur of 0.435 °. The moving amount of the lens element C is 0.428 (mm).

  Further, in the intermediate focal length of the optical system S1 according to the present embodiment, the image stabilization coefficient K when the image blur is corrected by the lens element A is 1.26, and the focal length is 163.1 (mm). Therefore, the movement amount of the lens element A for correcting the rotational shake of 0.301 ° is 0.680 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.37 and the focal length is 163.1 (mm), it is necessary to correct the rotation blur of 0.326 °. The moving amount of the lens element B is 0.680 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element C is 1.69 and the focal length is 163.1 (mm), it is necessary to correct the rotation blur of 0.403 °. The moving amount of the lens element C is 0.680 (mm).

  In the telephoto end state of the optical system S1 according to the present embodiment, the image stabilization coefficient K when correcting the image blur by the lens element A is 1.26, and the focal length is 226.6 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 0.210 ° is 0.944 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.37 and the focal length is 226.6 (mm), it is necessary to correct the rotation blur of 0.326 °. The moving amount of the lens element B is 0.944 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element C is 1.69 and the focal length is 226.6 (mm), it is necessary to correct the rotation blur of 0.403 °. The moving amount of the lens element C is 0.944 (mm).

  In this way, at each focal length, the image stabilization coefficient K increases in the order of the lens element A, the lens element B, and the lens element C, so that more corrections can be made. That is, if the focal length is the same and the movement amounts of the lens elements A, B, and C are the same as described above, the lens element B can correct a larger amount than the lens element A. The lens element C can correct a larger amount than the element B. Therefore, when the correction amount is small, the lens element A is driven, and when the correction amount increases and reaches a predetermined amount, the lens element B is driven, and the correction amount further increases and is set to a value larger than the predetermined amount. If the lens element C is controlled to be driven when the other predetermined amount is reached, even if the correction amount increases, more correction can be made without increasing the movement amount of the image stabilizing lens. As a result, from the wide-angle end state to the telephoto end state, the shift amount can be controlled to an appropriate amount without largely shifting the image stabilizing lens group.

  Table 1 below lists specifications of the optical system S1 according to the first example of the present invention.

  In [Overall specifications] in Table 1, f indicates a focal length, FNO indicates an F number, TL indicates a full length, W indicates a wide angle end state, M indicates an intermediate focal length state, and T indicates a telephoto end state. In [Surface Data], the surface number is the order of the lens surfaces counted from the object side, r is the radius of curvature of the lens surfaces, d is the distance between the lens surfaces, nd is the refractive index with respect to the d-line (wavelength λ = 587.6 nm), νd represents the Abbe number for the d-line (wavelength λ = 587.6 nm). The object plane indicates the object plane, (aperture) indicates the aperture stop SP, and the image plane indicates the image plane I. Note that the radius of curvature r = ∞ indicates a plane, and the description of the refractive index of air d = 1.00000 is omitted. When the lens surface is an aspheric surface, the surface number is marked with * and the paraxial radius of curvature is shown in the column of the radius of curvature r.

  [Aspherical data] shows the paraxial radius of curvature r, conic constant κ, and aspherical coefficients A4 to A12 when the shape of the aspherical surface shown in [Surface data] is expressed by the following equation.

x = (h ² / r) / [1+ {1-κ (h / r) ² } ^1/2 ] + A4h ⁴ + A6h ⁶ + A8y ⁸ + A10h ¹⁰ + A12h ¹²
Here, x is the displacement in the optical axis direction at the position of the height h from the optical axis when the vertex of the surface is used as a reference. In addition, “E−n” indicates “× 10 ⁻ⁿ ”, for example, “1.234E-05” indicates “1.234 × 10 ⁻⁵ ”.

  [Variable interval data] indicates the focal length f and the value of the variable interval. [Conditional Expression Corresponding Value] indicates the corresponding value of each conditional expression.

  Here, “mm” is generally used as the unit of the focal length f, the radius of curvature r, and other lengths described in Table 1. However, the optical system is not limited to this because an equivalent optical performance can be obtained even when proportionally enlarged or proportionally reduced.

  In addition, the code | symbol of Table 1 described above shall be similarly used also in the table | surface of each Example mentioned later.

(Table 1) First Example [Overall Specifications]
W M T
f 95.0 163.1 226.6
FNO 4.68 4.68 4.70
TL 259.3 259.3 259.3

[Surface data]
Surface number r d νd nd
Object ∞
1) 134.560 1.8 25.43 1.80518
2) 101.277 7.0 82.51 1.49782
3) 546.812 1.0
4) 77.194 4.0 82.51 1.49782
5) 124.044 D5
6) 40.981 5.0 25.68 1.78472
7) 59.996 1.5 40.77 1.88300
8) 36.961 6.7
9) −131.117 3.4 25.43 1.80518
10) −53.784 1.5 40.77 1.88300
11) 197.416 D11
12) −172.226 3.0 27.51 1.75520
13) −80.000 2.0 43.69 1.72000
14) −364.448 D14
15> Aperture 3.0
16) −636.174 4.0 82.51 1.49782
17) −57.515 0.3
18) 84.998 6.0 70.45 1.48749
19) −47.705 2.0 35.04 1.74950
20) −289.998 25.9
21) 70.499 4.6 82.56 1.49782
22) −117.909 25.9
23) −188.780 3.5 28.46 1.72825
24) −111.267 1.5 47.38 1.78800
25) 46.602 5.0
26) −119.084 2.0 58.89 1.51823
27) -220.000 5.0
28) −30.419 3.0 64.12 1.51680
29) −48.713 0.2
30) 228.879 5.0 44.79 1.74400
31) −64.531 BF
Image plane ∞

[Variable interval data]
W M T
D5 1.6 46.7 68.9
D11 61.4 2.5 3.4
D14 11.8 25.7 2.7
BF 50.6 50.6 50.6

[Values for each conditional expression]
fA = -46.5
fB = -42.3
fC = -32.5
(1) | fA |> | fB |: 46.5> 42.3
(2) | fB | / | fA | = 0.91
(3) | fA |> | fB |> | fC |: 46.5>42.3> 32.5
(4) | fC | / | fA | = 0.70

  FIG. 2A is a diagram illustrating various aberrations of the optical system S1 according to the first example in the wide-angle end state at the time of focusing on infinity. FIGS. 2B, 2C, and 2D are respectively related to the drawings. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed by the lens element A, the lens element B, and the lens element C in the wide-angle end state.

  FIG. 3A is a diagram of various aberrations in the intermediate focal length state at the time of focusing on infinity of the optical system S1 according to the first example, and FIGS. 3B, 3C, and 3D are respectively shown in FIG. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed by the lens element A, the lens element B, and the lens element C in the intermediate focal length state.

  FIG. 4A is a diagram illustrating various aberrations in the telephoto end state of the optical system S1 according to the first example when focusing on infinity, and FIGS. 4B, 4C, and 4D are respectively related to the drawing. FIG. 7 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A, the lens element B, and the lens element C in the telephoto end state.

  In each aberration diagram, FNO indicates an F number, and Y indicates an image height. Further, d in the figure indicates an aberration curve at the d-line (wavelength λ = 587.6 nm), and g indicates an aberration curve at the g-line (wavelength λ = 435.8 nm). In the aberration diagram showing astigmatism, the solid line indicates the sagittal image plane, and the broken line indicates the meridional image plane. In addition, in the various aberration diagrams of the following examples, the same reference numerals as those of the present example are used.

  As is apparent from each aberration diagram, it can be seen that the first example has excellent imaging performance from the wide-angle end state to the telephoto end state.

(Second embodiment)
FIG. 5 is a diagram showing the configuration of the optical system S2 according to the second embodiment of the present invention.

  As shown in FIG. 5, the optical system S2 according to the present example includes a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, in order from an object side (not shown), It comprises an aperture stop SP, a third lens group G3 having a negative refractive power, and a fourth lens group G4 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, a biconcave negative lens L12, and a positive meniscus lens L13 having a convex surface facing the object side. The most object-side negative meniscus lens L11 is an aspheric lens in which a resin layer is provided on the glass lens surface on the image plane I side to form an aspheric surface.

  The second lens group G2 includes, in order from the object side, a cemented lens L21 of a concave meniscus lens having a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens L22 having a convex surface facing the object side. Has been.

  The third lens group G3 includes, in order from the object side, a cemented lens L31 of a positive meniscus lens having a concave surface facing the object side and a biconcave negative lens, and a plano-concave lens L32 having a concave surface facing the object side. ing.

  The fourth lens group G4 includes, in order from the object side, a planoconvex lens L41 having a flat object side, and a cemented lens L42 including a biconvex positive lens and a negative meniscus lens having a convex surface facing the image plane I side. Yes.

  On the image plane I, an image sensor (not shown) made up of a CCD, a CMOS, or the like is disposed. The aperture stop SP is disposed between the second lens group G2 and the third lens group G3, and moves together with the third lens group G3 when zooming from the wide-angle end state to the telephoto end state.

  In the optical system S2 according to the present example, when zooming from the wide-angle end state to the telephoto end state, the first lens group G1 moves toward the image plane I, and the second lens group G2 and the fourth lens group G4. Moves together to the object side, and the third lens group G3 moves to the object side.

  The optical system S2 according to the present embodiment uses the cemented lens L31 in the third lens group G3 as the lens element A, and the plano-concave lens L32 having the same refractive power as the lens element A and the refractive power of the lens element A. The lens element B is configured with the lens element A and the lens element B as an anti-vibration lens group. By shifting any one of these anti-vibration lens groups in a direction orthogonal to the optical axis, blurring of the captured image is prevented.

  In the optical system S2 according to the present embodiment, when the focal length of the entire optical system S2 is f and the image stabilization coefficient at the time of blur correction is K, the lens for blur correction is used to correct the rotational blur at the angle θ. The group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.

  The focal length f of the entire system in the wide-angle end state, the intermediate focal length, and the telephoto end state of the optical system S2 according to the present embodiment is 18.5 (mm), 35.0 (mm), and 53.5 (mm), respectively. (See Table 2 below). The blur correction amount by the lens elements A and B and the movement amount of the lens elements A and B at each focal length are, for example, as follows.

  In the optical system S2 according to the present embodiment, in the wide-angle end state, the image stabilization coefficient K when the image blur is corrected by the lens element A is 1.04, and the focal length is 18.5 (mm). Therefore, the moving amount of the lens element A for correcting the rotation blur of 0.735 ° is 0.227 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.39 and the focal length is 18.5 (mm), it is necessary to correct the rotation blur of 0.927 °. The moving amount of the lens element B is 0.216 (mm).

  Further, in the intermediate focal length of the optical system S2 according to the present embodiment, the image stabilization coefficient K when correcting the image blur by the lens element A is 1.29, and the focal length is 35.0 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 0.534 ° is 0.252 (mm). In addition, the image stabilization coefficient K when correcting the image blur by the lens element B is 1.71, and the focal length is 35.0 (mm), so that the rotational blur of 0.681 ° is corrected. The moving amount of the lens element B is 0.243 (mm).

  In the telephoto end state of the optical system S2 according to the present example, the image stabilization coefficient K when correcting the image blur by the lens element A is 1.66, and the focal length is 53.5 (mm). Therefore, the moving amount of the lens element A for correcting the rotation blur of 0.432 ° is 0.243 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 2.18 and the focal length is 53.5 (mm), it is necessary to correct the rotational blur of 0.553 °. The moving amount of the lens element B is 0.236 (mm).

  As described above, since the image stabilization coefficient K increases in the order of the lens element A and the lens element B, more correction can be performed. That is, when the focal length is the same as described above, the lens element B can be corrected by a larger amount than the lens element A, although the movement amount is smaller than that of the lens element A. Accordingly, if the correction amount is small, the lens element A is driven, and if the correction amount increases and reaches the predetermined amount, the lens element B is controlled so that the vibration-proof lens group moves even if the correction amount increases. More corrections are possible without increasing the amount. As a result, from the wide-angle end state to the telephoto end state, the shift amount can be controlled to an appropriate amount without largely shifting the image stabilizing lens group.

  Table 2 below lists specifications of the optical system S2 according to the second example of the present invention.

(Table 2) Second embodiment [Overall specifications]
W M T
f 18.5 35.0 53.5
FNO 3.6 4.1 5.3
TL 130.2 122.3 131.5

[Surface data]
Surface number r d νd nd
Object ∞
1) 115.556 1.9 64.12 1.51680
2) 15.601 0.2 38.09 1.55389
* 3) 13.300 10.0
4) -159.479 1.5 58.22 1.62299
5) 35.685 1.1
6) 28.207 3.1 25.68 1.78472
7) 77.398 D7
8) 32.321 0.9 23.78 1.84666
9) 17.691 4.3 58.89 1.51823
10) −32.688 0.1
11) 23.144 1.8 64.10 1.5168
12) 59.408 D12
13> Aperture 2.9
14) −40.000 2.75 32.40 1.85026
15) −12.280 0.8 46.60 1.804
16) 114.994 3.0
17) −90.000 1.4 70.50 1.48749
18) 0.000 D18
19) 0.000 3.2 52.30 1.51742
20) -21.120 0.1
21) 128.036 5.3 70.50 1.48749
22) −15.933 1.3 32.40 1.85026
23) −44.265 BF
Image plane ∞

[Aspherical data]
Surface number: 3
κ = 1
A4 = 2.63599E−05
A6 = 7.76960E−08
A8 = -1.94524E-10
A10 = 1.27950E-12

[Variable interval data]
W M T
D7 32.3 20.8 9.7
D12 2.6 4.3 8.0
D18 9.6 7.8 4.2
BF 38.1 43.4 52.8

[Values for each conditional expression]
fA = −40.6
fB = -32.6
(1) | fA |> | fB |: 40.6> 32.6
(2) | fB | / | fA | = 0.80

  FIG. 6A is a diagram illustrating various aberrations in the wide-angle end state when the optical system S2 according to Example 2 is focused at infinity, and FIGS. 6B and 6C are graphs in the wide-angle end state, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  FIG. 7A is a diagram of various aberrations in the intermediate focal length state at the time of focusing on infinity of the optical system S2 according to the second example. FIGS. 7B and 7C are respectively the intermediate focal lengths. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A and the lens element B in a state.

  FIG. 8A is a diagram illustrating various aberrations in the telephoto end state when the optical system S2 according to Example 2 is focused at infinity, and FIGS. 8B and 8C are graphs in the telephoto end state, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  As is apparent from each aberration diagram, it can be seen that the second embodiment has excellent imaging performance from the wide-angle end state to the telephoto end state.

(Third embodiment)
FIG. 9 is a diagram showing the configuration of the optical system S3 according to the third embodiment of the present invention.

  As shown in FIG. 9, the optical system S3 according to the present embodiment includes, in order from the object side (not shown), a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, It comprises an aperture stop SP, a third lens group G3 having a negative refractive power, and a fourth lens group G4 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a negative meniscus lens L11 having a convex surface facing the object side, a biconcave negative lens L12, and a positive meniscus lens L13 having a convex surface facing the object side. The most object-side negative meniscus lens L11 is an aspheric lens in which a resin layer is provided on the glass lens surface on the image plane I side to form an aspheric surface.

  The second lens group G2 includes, in order from the object side, a cemented lens L21 of a concave meniscus lens having a convex surface facing the object side and a biconvex positive lens, and a positive meniscus lens L22 having a convex surface facing the object side. Has been.

  The third lens group G3 includes, in order from the object side, a cemented lens L31 of a positive meniscus lens having a concave surface facing the object side and a biconcave negative lens, and a plano-concave lens L32 having a concave surface facing the object side. ing.

  The fourth lens group G4 includes, in order from the object side, a planoconvex lens L41 having a flat object side, and a cemented lens L42 including a biconvex positive lens and a negative meniscus lens having a convex surface facing the image plane I side. Yes.

  On the image plane I, an image sensor (not shown) made up of a CCD, a CMOS, or the like is disposed. The aperture stop SP is disposed between the second lens group G2 and the third lens group G3, and moves together with the third lens group G3 when zooming from the wide-angle end state to the telephoto end state.

  In the optical system S3 according to the present example, when zooming from the wide-angle end state to the telephoto end state, the first lens group G1 moves along a convex locus toward the image plane I, and the second lens group G2, The four lens group G4 moves integrally to the object side, and the third lens group G3 moves to the object side.

  In the optical system S3 according to the present embodiment, the cemented lens L21 in the second lens group G2 is the lens element A, and a positive meniscus lens L22 having the same refractive power as that of the lens element A and the lens element A is used. The lens element B is composed of the lens element A and the lens element B as a vibration-proof lens group. By shifting any one of these anti-vibration lens groups in a direction orthogonal to the optical axis, blurring of the captured image is prevented.

  In the optical system S3 according to the present embodiment, when the focal length of the entire optical system S3 is f and the image stabilization coefficient at the time of blur correction is K, the lens for blur correction is used to correct the rotational blur at the angle θ. The group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.

  The focal length f of the entire system in the wide-angle end state, the intermediate focal length, and the telephoto end state of the optical system S3 according to the present embodiment is 18.5 (mm), 35.0 (mm), and 53.5 (mm), respectively. (See Table 3 below). The blur correction amount by the lens elements A and B and the movement amount of the lens elements A and B at each focal length are, for example, as follows.

  In the optical system S3 according to the present example, in the wide-angle end state, the image stabilization coefficient K when the image blur is corrected by the lens element A is 1.39, and the focal length is 18.5 (mm). Therefore, the moving amount of the lens element A for correcting the rotation blur of 0.735 ° is 0.170 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.92 and the focal length is 18.5 (mm), it is necessary to correct the rotational blur of 1.014 °. The moving amount of the lens element B is 0.170 (mm).

  In the intermediate focal length of the optical system S3 according to the present embodiment, the image stabilization coefficient K when correcting the image blur by the lens element A is 1.80, and the focal length is 35.0 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 0.534 ° is 0.181 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.92 and the focal length is 35.0 (mm), it is necessary to correct the rotation blur of 0.742 °. The moving amount of the lens element B is 0.181 (mm).

  In the telephoto end state of the optical system S3 according to the present example, the image stabilization coefficient K when correcting the image blur by the lens element A is 2.31, and the focal length is 53.5 (mm). Therefore, the moving amount of the lens element A for correcting the rotation blur of 0.432 ° is 0.174 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 3.21 and the focal length is 53.5 (mm), it is necessary to correct the rotation blur of 0.600 °. The moving amount of the lens element B is 0.174 (mm).

  As described above, since the image stabilization coefficient K increases in the order of the lens element A and the lens element B, more correction can be performed. That is, if the focal length is the same and the movement amounts of the lens elements A and B are the same as described above, the lens element B can correct a larger amount than the lens element A. Therefore, when the correction amount is small, the lens element A is driven, and when the correction amount increases and reaches a predetermined amount, the lens element B is driven. More corrections can be made without increasing the amount of movement. As a result, from the wide-angle end state to the telephoto end state, the shift amount can be controlled to an appropriate amount without largely shifting the image stabilizing lens group.

  Table 3 below lists specifications of the optical system S3 according to the third example of the present invention.

(Table 3) Third Example [Overall Specifications]
W M T
f 18.5 35.0 53.5
FNO 3.6 4.0 5.2
TL 130.8 121.9 130.2

[Surface data]
Surface number r d νd nd
Object ∞
1) 115.450 1.9 64.12 1.51680
2) 15.601 0.2 38.09 1.55389
* 3) 13.300 10.0
4) −145.545 1.5 58.22 1.62299
5) 39.812 1.1
6) 28.306 3.1 25.68 1.78472
7) 67.883 D7
8) 29.022 0.9 23.78 1.84666
9) 16.347 4.3 58.89 1.51823
10) −31.176 0.1
11) 23.440 1.8 64.12 1.51680
12) 59.408 D12
13> Aperture 2.9
14) −36.200 2.8 32.35 1.85026
15) −11.078 0.8 46.58 1.80 400
16) 114.994 3.0
17) −68.000 1.4 70.45 1.48749
18) 0.000 D18
19) −125.598 3.2 52.32 1.51742
20) −20.199 0.1
21) 72.314 5.3 70.45 1.48749
22) −16.608 1.3 32.35 1.85026
23) −44.265 BF
Image plane ∞

[Aspherical data]
Surface number: 3
κ = 1
A4 = 2.71636E−05
A6 = 7.76960E−08
A8 = -1.73581E-10
A10 = 1.27950E-12

[Variable interval data]
W M T
D7 32.3 9.7 2.2
D12 2.6 8.0 12.2
D18 12.1 6.7 2.5
BF 38.1 54.0 67.7

[Values for each conditional expression]
fA = + 39.5
fB = + 25.9
(1) | fA |> | fB |: 39.5> 25.9
(2) | fB | / | fA | = 0.66

  FIG. 10A is a diagram illustrating various aberrations in the wide-angle end state when the optical system S3 according to Example 3 is in focus at infinity, and FIGS. 10B and 10C are respectively the wide-angle end state. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  FIG. 11A is a diagram of various aberrations in the intermediate focal length state at the time of focusing on infinity of the optical system S3 according to the third example. FIGS. 11B and 11C are respectively the intermediate focal lengths. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A and the lens element B in a state.

  FIG. 12A is a diagram illustrating various aberrations in the telephoto end state of the optical system S3 according to the third example when focusing on infinity. FIGS. 12B and 12C are graphs in the telephoto end state, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  As is apparent from each aberration diagram, it can be seen that the third example has excellent imaging performance from the wide-angle end state to the telephoto end state.

(Fourth embodiment)
FIG. 13 is a diagram showing a configuration of an optical system S4 according to the fourth example of the present invention.

  As shown in FIG. 13, the optical system S4 according to the present example includes, in order from an object side (not shown), a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, The aperture stop SP, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a cemented lens L11 of a negative meniscus lens having a convex surface facing the object side and a biconvex lens, and a positive meniscus lens L12 having a convex surface facing the object side.

  The second lens group G2, in order from the object side, has an aspheric shape on the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave lens L22, a biconvex lens L23, and a concave surface on the object side. And a negative meniscus lens L24 directed to it.

  The third lens group G3 includes, in order from the object side, a biconvex lens L31 and a cemented lens L32 of a biconvex lens and a negative meniscus lens having a concave surface facing the object side.

  The fourth lens group G4 includes, in order from the object side, a cemented lens L41 of a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side, a biconcave lens L42, and a biconcave lens L43. It is configured.

  The fifth lens group G5 includes, in order from the object side, a biconvex lens L51 having an aspheric shape on the image plane I side, a biconvex lens L52, and a negative meniscus lens L53 having a concave surface facing the object side. .

  On the image plane I, an image sensor (not shown) made up of a CCD, a CMOS, or the like is disposed. The aperture stop SP is disposed between the second lens group G2 and the third lens group G3, and moves together with the third lens group G3 when zooming from the wide-angle end state to the telephoto end state.

  The optical system S4 according to the present embodiment has a first lens group G1, a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens when zooming from the wide-angle end state to the telephoto end state. The lens group G5 moves to the object side.

  The optical system S4 according to the present embodiment uses the cemented lens L41 in the fourth lens group G4 as the lens element A, and the lens element A and the biconcave lens L42 having the same sign as the refractive power of the lens element A. The lens element B is composed of the lens element B, and the lens element C is composed of the lens element B and the biconcave lens L43 having the same sign as that of the lens element B. The lens element A, the lens element B, and the lens element C Are set as anti-vibration lens groups. By shifting any one of these anti-vibration lens groups in a direction orthogonal to the optical axis, blurring of the captured image is prevented.

  In the optical system S4 according to the present embodiment, when the focal length of the entire optical system S4 is f and the image stabilization coefficient at the time of blur correction is K, in order to correct the rotational blur at the angle θ, the lens for blur correction is used. The group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.

  The focal lengths f of the entire system in the wide-angle end state, the intermediate focal length, and the telephoto end state of the optical system S4 according to the present embodiment are 18.7 (mm), 70.6 (mm), and 188.0 (mm), respectively. (See Table 4 below). The blur correction amounts by the lens elements A, B, and C and the movement amounts of the lens elements A, B, and C at each focal length are as follows, for example.

  In the optical system S4 according to the present example, in the wide-angle end state, the image stabilization coefficient K when the image blur is corrected by the lens element A is 0.51, and the focal length is 18.7 (mm). Therefore, the moving amount of the lens element A for correcting the rotational shake of 0.623 ° is 0.400 (mm). Further, the image stabilization coefficient K when correcting the image blur by the lens element B is 0.61, and the focal length is 18.7 (mm), so that the rotational blur of 0.746 ° is corrected. The moving amount of the lens element B is 0.400 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element C is 1.69 and the focal length is 18.7 (mm), it is necessary to correct the rotational blur of 1.461 °. The moving amount of the lens element C is 0.400 (mm).

  In the intermediate focal length of the optical system S4 according to the present embodiment, the image stabilization coefficient K when the image blur is corrected by the lens element A is 0.82, and the focal length is 70.6 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 0.267 ° is 0.399 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 0.99 and the focal length is 70.6 (mm), it is necessary to correct the rotational blur of 0.321 °. The moving amount of the lens element B is 0.399 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element C is 1.95 and the focal length is 70.6 (mm), it is necessary to correct the rotation blur of 0.630 °. The moving amount of the lens element C is 0.399 (mm).

  In the telephoto end state of the optical system S4 according to the present embodiment, the image stabilization coefficient K when correcting the image blur by the lens element A is 1.04, and the focal length is 188.0 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 0.126 ° is 0.400 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.25 and the focal length is 188.0 (mm), it is necessary to correct the rotational blur of 0.152 °. The moving amount of the lens element B is 0.400 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element C is 2.46 and the focal length is 188.0 (mm), it is necessary to correct the rotation blur of 0.197 °. The moving amount of the lens element C is 0.400 (mm).

  As described above, since the image stabilization coefficient K increases in the order of the lens element A, the lens element B, and the lens element C, more correction can be performed. That is, if the focal length is the same and the movement amounts of the lens elements A, B, and C are the same as described above, the lens element B can correct a larger amount than the lens element A. The lens element C can correct a larger amount than the element B. Therefore, when the correction amount is small, the lens element A is driven, and when the correction amount increases and reaches a predetermined amount, the lens element B is driven, and the correction amount further increases and is set to a value larger than the predetermined amount. If the lens element C is controlled to be driven when the other predetermined amount is reached, even if the correction amount increases, more correction can be performed without increasing the movement amount of the image stabilizing lens group. As a result, from the wide-angle end state to the telephoto end state, the shift amount can be controlled to an appropriate amount without largely shifting the image stabilizing lens group.

  Table 4 below lists specifications of the optical system S4 according to the fourth example of the present invention.

(Table 4) Fourth Example [Overall Specifications]
W M T
f 18.7 70.0 188.0
FNO 3.64 5.44 6.60
TL 128.6 180.3 216.7

[Surface data]
Surface number r d νd nd
Object ∞
1) 128.56287 1.8 37.18 1.834
2) 61.71903 9.4 82.57 1.49782
3) −368.67603 0.12
4) 55.98016 6.8 82.57 1.49782
5) 389.22661 D5
* 6) 43.51896 1.2 47.25 1.77377
7) 11.20367 6.4
8) −27.87211 1.0 40.66 1.88300
9) 45.04115 0.15
10) 26.85149 4.22 23.8 1.84666
11) −30.94189 1.05
12) −19.31231 1.0 46.6 1.80 400
13) −58.68682 D13
14> Aperture 1.63
15) 31.09309 3.18 82.57 1.49782
16) −66.2335 0.12
17) 24.20499 4.26 82.57 1.49782
18) −22.11253 0.9 25.45 1.80518
19) −90.15429 D19
20) 90.00000 0.8 52.77 1.74100
21) 15.29423 2.5 25.45 1.80518
22) 33.33188 1.4
23) −450.00000 0.8 63.88 1.51680
24) 459.94923 1.2
25) −80.00000 1.2 54.61 1.72916
26) 183.82631 D26
27) 275.95449 4.0 82.47 1.49697
* 28) -21.43596 0.08
29) 55.21481 4.25 70.31 1.48749
30) −30.00000 1.4
31) −15.80000 1.63 37.18 1.83400
32) −31.79204 BF
Image plane ∞

[Aspherical data]
Surface number: 6
κ = −45.4463
A4 = 6.97E−05
A6 = −5.50E−07
A8 = 3.61E−09
A10 = −1.46E−11
A12 = 2.48E-14

Surface number: 28
κ = −5.3904
A4 = −9.11E−05
A6 = 3.36E-07
A8 = -2.85E-09
A10 = 1.17E-11
A12 = −3.50E-14

[Variable interval data]
W M T
D5 1.0 36.0 56.8
D13 23.1 8.3 1.0
D19 0.9 1.1 2.3
D26 2.9 2.3 2.3
BF 38.7 70.6 92.2

[Values for each conditional expression]
fA = −89.0
fB = −74.1
fC = -37.2
(1) | fA |> | fB |: 89.0> 74.1
(2) | fB | / | fA | = 0.83
(3) | fA |> | fB |> | fC |: 89.0>74.1> 37.2
(4) | fC | / | fA | = 0.42

  FIG. 14A is a diagram illustrating various aberrations of the optical system S4 according to Example 4 in the wide-angle end state at the time of focusing on infinity. FIGS. 14B, 14C, and 14D are respectively the same. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed by the lens element A, the lens element B, and the lens element C in the wide-angle end state.

  FIG. 15A is a diagram of various aberrations in the intermediate focal length state at the time of focusing on infinity of the optical system S4 according to the fourth example, and FIGS. 15B, C, and D are respectively FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed by the lens element A, the lens element B, and the lens element C in the intermediate focal length state.

  FIG. 16A is a diagram of various aberrations of the optical system S4 according to Example 4 in the telephoto end state when focused on infinity. FIGS. 16B and 16C are graphs showing the aberrations, respectively. FIG. 7 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A, the lens element B, and the lens element C in the telephoto end state.

  As is apparent from each aberration diagram, it can be seen that the fourth example has excellent imaging performance from the wide-angle end state to the telephoto end state.

(5th Example)
FIG. 17 is a diagram showing a configuration of an optical system S5 according to the fifth example of the present invention.

  As shown in FIG. 17, the optical system S5 according to the present example includes, in order from an object side (not shown), a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, It comprises an aperture stop SP, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power.

  The first lens group G1 includes, in order from the object side, a cemented lens L11 of a negative meniscus lens having a convex surface facing the object side and a biconvex lens, and a positive meniscus lens L12 having a convex surface facing the object side.

  The second lens group G2, in order from the object side, has an aspheric shape on the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave lens L22, a biconvex lens L23, and a concave surface on the object side. And a negative meniscus lens L24 directed to it.

  The third lens group G3 includes, in order from the object side, a biconvex lens L31 and a cemented lens L32 of a biconvex lens and a negative meniscus lens having a concave surface facing the object side.

  The fourth lens group G4 includes, in order from the object side, a cemented lens L41 of a biconcave lens and a positive meniscus lens having a convex surface directed toward the object side, a biconcave lens L42, a biconvex lens L43, and an image surface I side having an aspheric shape. It is composed of a convex meniscus lens L44 having a concave surface facing the object side, a biconvex lens L45, and a negative meniscus lens L46 having a concave surface facing the object side.

  On the image plane I, an image sensor (not shown) made up of a CCD, a CMOS, or the like is disposed. The aperture stop SP is disposed between the second lens group G2 and the third lens group G3, and moves together with the third lens group G3 when zooming from the wide-angle end state to the telephoto end state.

  In the optical system S5 according to the present embodiment, the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 are on the object side during zooming from the wide-angle end state to the telephoto end state. Move to.

  In the optical system S5 according to the present embodiment, the cemented lens L41 and the biconcave lens L42 in the fourth lens group G4 constitute a lens element A. The lens element B is composed of the biconvex lens L43 having power, and each of the lens element A and the lens element B is used as an anti-vibration lens group. By shifting any one of these anti-vibration lens groups in a direction orthogonal to the optical axis, blurring of the captured image is prevented.

  In the optical system S5 according to the present embodiment, when the focal length of the entire optical system S5 is f and the image stabilization coefficient at the time of blur correction is K, a lens for blur correction is used to correct the rotational blur at the angle θ. The group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.

  The focal lengths f of the entire system in the wide-angle end state, the intermediate focal length, and the telephoto end state of the optical system S5 according to the present embodiment are 18.7 (mm), 70.1 (mm), and 188.0 (mm), respectively. (See Table 5 below). For example, the blur correction amount by the lens elements A and B and the movement amount of each lens element at each focal length are as follows.

  In the optical system S5 according to the present example, in the wide-angle end state, the image stabilization coefficient K when the image blur is corrected by the lens element A is 1.14, and the focal length is 18.7 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 1.466 ° is 0.421 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 0.60 and the focal length is 18.7 (mm), it is necessary to correct the rotation blur of 0.772 °. The moving amount of the lens element B is 0.421 (mm).

  Further, in the intermediate focal length of the optical system S5 according to the present embodiment, the image stabilization coefficient K when the image blur is corrected by the lens element A is 1.83, and the focal length is 70.1 (mm). Therefore, the moving amount of the lens element A for correcting the rotational shake of 0.630 ° is 0.421 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 0.94 and the focal length is 70.1 (mm), it is necessary to correct the rotation blur of 0.322 °. The moving amount of the lens element B is 0.421 (mm).

  In the telephoto end state of the optical system S5 according to the present embodiment, the image stabilization coefficient K when correcting the image blur by the lens element A is 2.31, and the focal length is 188.0 (mm). Therefore, the moving amount of the lens element A for correcting the rotational shake of 0.296 ° is 0.421 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.17 and the focal length is 188.0 (mm), it is necessary to correct the rotation blur of 0.150 °. The moving amount of the lens element B is 0.421 (mm).

  Thus, in this embodiment, the image stabilization coefficient K increases in the order of the lens element B and the lens element A. That is, more correction is possible when the image blur is corrected by the lens element A than by the lens element B. As described above, if the focal length is the same and the movement amounts of the lens elements A and B are the same, the lens element A can correct a larger amount than the lens element B. Therefore, when the correction amount is small, the lens element B is driven, and when the correction amount increases and reaches a predetermined amount, the lens element A is driven. More corrections can be made without increasing the amount of movement. As a result, from the wide-angle end state to the telephoto end state, the shift amount can be controlled to an appropriate amount without largely shifting the image stabilizing lens group.

  Table 5 below lists specifications of the optical system S5 according to the fifth example of the present invention.

(Table 5) Fifth embodiment [Overall specifications]
W M T
f 18.7 70.1 188.0
FNO 3.64 5.60 6.97
TL 130.1 182.0 219.2

[Surface data]
Surface number r d νd nd
Object ∞
1) 133.26500 1.4 37.18 1.83400
2) 63.25833 9.2 82.57 1.49782
3) −305.56559 0.12
4) 58.40597 6.4 82.57 1.49782
5) 444.97253 D5
* 6) 45.03974 1.2 47.25 1.77377
7) 11.11015 6.4
8) −24.09331 1.0 40.66 1.88300
9) 68.33997 0.15
10) 31.75544 4.22 23.78 1.84666
11) −28.74651 1.05
12) -17.39728 1.0 46.6 1.80 400
13) −38.14366 D13
14> Aperture 1.63
15) 26.85327 3.18 82.57 1.49782
16) −48.92537 0.12
17) 28.73946 4.26 82.57 1.49782
18) −24.20835 0.9 25.4 1.80518
19) −150.19371 D19
20) −200.00000 0.8 52.77 1.74100
21) 19.52804 2.5 25.44 1.80518
22) 66.76603 2.0
23) −500.00000 0.8 54.61 1.72916
24) 68.99538 1.2
25) 184.90012 1.9 63.88 1.51680
26) −57.41433 2.3
27) -29.69333 3.0 82.47 1.49697
* 28) -23.59223 0.08
29) 52.67285 4.25 70.31 1.48749
30) −20.13027 1.4
31) −15.95804 1.63 37.18 1.83400
32) −35.63406 BF
Image plane ∞

[Aspherical data]
Surface number: 6
κ = −42.8927
A4 = 6.52E−05
A6 = -4.25E-07
A8 = 2.51E−09
A10 = −9.91E−12
A12 = 1.83E-14

Surface number: 28
κ = -7.2004
A4 = -7.79E-05
A6 = 4.39E-07
A8 = −4.25E−09
A10 = 3.18E-11
A12 = −1.36E−13

[Variable interval data]
W M T
D5 1.0 36.0 56.8
D13 24.8 8.7 1.0
D19 1.5 1.9 3.7
BF 38.7 71.3 93.5

[Values for each conditional expression]
fA = -40.1
fB = -82.5
(5) | fA | <| fB |: 40.1 <82.5
(6) | fA | / | fB | = 0.486

  FIG. 18A is a diagram illustrating various aberrations of the optical system S5 according to Example 5 in the wide-angle end state at the time of focusing on infinity, and FIGS. 18B and 18C are graphs in the wide-angle end state, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  FIG. 19A is a diagram illustrating various aberrations in the intermediate focal length state at the time of focusing on infinity of the optical system S5 according to the fifth example. FIGS. 19B and 19C are respectively the intermediate focal lengths. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A and the lens element B in a state.

  FIG. 20A is a diagram of various aberrations of the optical system S5 according to Example 5 in the telephoto end state at the time of focusing on infinity. FIGS. 20B and 20C are graphs in the telephoto end state, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  As is apparent from each aberration diagram, it can be seen that the fifth example has excellent imaging performance from the wide-angle end state to the telephoto end state.

(Sixth embodiment)
FIG. 21 is a diagram showing a configuration of an optical system S6 according to the sixth example of the present invention.

  As shown in FIG. 21, the optical system S6 according to the present example includes, in order from the object side (not shown), a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, The aperture stop SP, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a cemented lens L11 of a negative meniscus lens having a convex surface facing the object side and a convex meniscus lens having a convex surface facing the object side, and a biconvex lens L12.

  The second lens group G2, in order from the object side, has an aspheric shape on the object side, a negative meniscus lens L21 having a convex surface facing the object side, a biconcave lens L22, a biconvex lens L23, and a concave surface on the object side. And a negative meniscus lens L24 directed to it.

  The third lens group G3 includes, in order from the object side, a biconvex lens L31 and a cemented lens L32 of a biconvex lens and a negative meniscus lens having a concave surface facing the object side.

  The fourth lens group G4 includes, in order from the object side, a cemented lens L41 of a negative meniscus lens having a convex surface directed toward the object side and a positive meniscus lens having a convex surface directed toward the object side, and a concave meniscus lens having a concave surface directed toward the object side L42 and a convex meniscus lens L43 having a concave surface facing the object side.

  The fifth lens group G5 has, in order from the object side, an aspheric shape on the image plane I side, a convex meniscus lens L51 having a concave surface directed toward the object side, a biconvex lens L52, and a negative surface having a concave surface directed toward the object side. And a meniscus lens L53.

  On the image plane I, an image sensor (not shown) made up of a CCD, a CMOS, or the like is disposed. The aperture stop SP is disposed between the second lens group G2 and the third lens group G3, and moves together with the third lens group G3 when zooming from the wide-angle end state to the telephoto end state.

  The optical system S6 according to the present example has a first lens group G1, a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens when zooming from the wide-angle end state to the telephoto end state. The lens group G5 moves to the object side.

  In the optical system S6 according to the present embodiment, the cemented lens L41 and the concave meniscus lens L42 in the fourth lens group G4 constitute a lens element A, and the refractive powers of the lens element A and the lens element A are different in sign. The convex meniscus lens L43 having refractive power constitutes a lens element B, and each of the lens element A and the lens element B is used as an anti-vibration lens group. By shifting any one of these anti-vibration lens groups in a direction orthogonal to the optical axis, blurring of the captured image is prevented.

  In the optical system S6 according to the present embodiment, when the focal length of the entire optical system S6 is f and the image stabilization coefficient at the time of blur correction is K, a lens for blur correction is used to correct the rotational blur at the angle θ. The group may be shifted in a direction orthogonal to the optical axis by (f · tan θ) / K.

  The focal lengths f of the entire system in the wide-angle end state, the intermediate focal length, and the telephoto end state of the optical system S6 according to the present embodiment are 18.7 (mm), 70.6 (mm), and 188.0 (mm), respectively. (See Table 6 below). For example, the blur correction amount by the lens elements A and B and the movement amount of each lens element at each focal length are as follows.

  In the optical system S6 according to the present example, in the wide-angle end state, the image stabilization coefficient K when correcting the image blur by the lens element A is 1.06, and the focal length is 18.7 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 1.446 ° is 0.446 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 0.62 and the focal length is 18.7 (mm), it is necessary to correct the rotation blur of 0.848 °. The moving amount of the lens element B is 0.446 (mm).

  Further, in the intermediate focal length of the optical system S6 according to the present embodiment, the image stabilization coefficient K when the image blur is corrected by the lens element A is 1.73, and the focal length is 70.6 (mm). Therefore, the moving amount of the lens element A for correcting the rotational blur of 0.631 ° is 0.446 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 0.99 and the focal length is 70.6 (mm), it is necessary to correct the rotation blur of 0.360 °. The moving amount of the lens element B is 0.446 (mm).

  In the telephoto end state of the optical system S6 according to the present embodiment, the image stabilization coefficient K when correcting the image blur by the lens element A is 2.21, and the focal length is 188.0 (mm). Therefore, the moving amount of the lens element A for correcting the rotation blur of 0.300 ° is 0.446 (mm). Further, since the image stabilization coefficient K when correcting the image blur by the lens element B is 1.25 and the focal length is 188.0 (mm), it is necessary to correct the rotational blur of 0.169 °. The moving amount of the lens element B is 0.446 (mm).

  Thus, in this embodiment, the image stabilization coefficient K increases in the order of the lens element B and the lens element A. That is, more correction is possible when the image blur is corrected by the lens element A than by the lens element B. As described above, if the focal length is the same and the movement amounts of the lens elements A and B are the same, the lens element A can correct a larger amount than the lens element B. Therefore, when the correction amount is small, the lens element B is driven, and when the correction amount increases and reaches a predetermined amount, the lens element A is driven. More corrections can be made without increasing the amount of movement. As a result, from the wide-angle end state to the telephoto end state, the shift amount can be controlled to an appropriate amount without largely shifting the image stabilizing lens group.

  Table 6 below lists specifications of the optical system S6 according to the sixth example of the present invention.

(Table 6) Sixth Example [Overall specifications]
W M T
f 18.7 70.0 188.0
FNO 3.55 5.39 6.91
TL 129.7 182.7 222.5

[Surface data]
Surface number r d νd nd
Object ∞
1) 88.3686 1.4 37.18 1.834
2) 51.2341 9.8 82.57 1.49782
3) 588.9823 0.12
4) 65.0932 6.4 82.57 1.49782
5) −3559.6410 D5
* 6) 37.4711 1.2 47.25 1.77377
7) 10.8979 6.4
8) -29.5092 1.0 40.66 1.88300
9) 58.3390 0.15
10) 26.3202 4.22 23.8 1.84666
11) −34.7037 1.05
12) −18.6 800 1.0 46.6 1.80 400
13) −67.5427 D13
14> Aperture 1.63
15) 23.9912 3.18 82.57 1.49782
16) −62.5375 0.12
17) 33.2119 4.26 82.57 1.49782
18) −21.0524 0.9 25.45 1.80518
19) −74.2470 D19
20) 358.8111 0.8 52.77 1.74100
21) 18.2134 2.5 25.45 1.80518
22) 45.8626 2.0
23) −50.0000 0.8 54.61 1.72916
24) −254.5612 1.2
25) −248.3650 1.9 65.44 1.60300
26) −49.5474 D26
27) −30.0000 4.0 82.47 1.49697
* 28) -20.4714 0.08
29) 43.8397 4.25 70.31 1.48749
30) −31.5343 1.4
31) −16.1983 1.63 37.18 1.83400
32) −30.0990 BF
Image plane ∞

[Aspherical data]
Surface number: 6
κ = −30.2672
A4 = 7.83E−05
A6 = −5.54E−07
A8 = 3.32E−09
A10 = −1.18E−11
A12 = 1.88E-14

Surface number: 28
κ = −4.9613
A4 = −9.15E−05
A6 = 3.67E-07
A8 = −3.27E−09
A10 = 1.76E-11
A12 = −6.39E−14

[Variable interval data]
W M T
D5 1.0 36.0 56.8
D13 23.9 8.3 1.0
D19 0.9 0.9 1.9
D26 1.8 1.8 2.3
BF 38.7 72.4 96.6

[Values for each conditional expression]
fA = -42.2
fB = -76.8
(5) | fA | <| fB |: 42.2 <76.8
(6) | fA | / | fB | = 0.55

  FIG. 22A is a diagram illustrating various aberrations of the optical system S6 according to Example 6 in the wide-angle end state at the time of focusing on infinity. FIGS. 22B and 22C are diagrams illustrating the aberration in the wide-angle end state, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  FIG. 23A is a diagram of various aberrations in the intermediate focal length state at the time of focusing on infinity of the optical system S6 according to the sixth example, and FIGS. 23B and C are the intermediate focal lengths, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with the lens element A and the lens element B in a state.

  FIG. 24A is a diagram of various aberrations of the optical system S6 according to Example 6 in the telephoto end state when focusing on infinity. FIGS. 24B and 24C are graphs in the telephoto end state, respectively. FIG. 6 is a meridional lateral aberration diagram when image blur correction is performed with lens element A and lens element B.

  As is apparent from each aberration diagram, it can be seen that the sixth example has excellent imaging performance from the wide-angle end state to the telephoto end state.

  As described above, according to each of the above embodiments, an optical system having a suitable image stabilization function can be realized.

  Here, each said Example has shown one specific example of this invention, and this invention is not limited to these. The contents described below can be appropriately adopted as long as the optical performance is not impaired.

  The numerical examples of the optical system according to the present invention are shown as having a four-group or five-group configuration, but the present invention is not limited to this, and an optical system of another group configuration (for example, six groups) can be configured. It is. Specifically, a configuration in which a lens or a lens group is added to the most object side of the optical system of the present invention, or a configuration in which a lens or a lens group is added to the most image side may be used. The lens group indicates a portion having at least one lens separated by an air interval.

  In addition, the optical system of the present invention uses a part of a lens group, an entire lens group, or a plurality of lens groups as a focusing lens group to focus on an object from infinity to a close object. It is good also as a structure moved to a direction. The focusing lens group can also be applied to autofocus, and is also suitable for driving by an autofocus motor, such as an ultrasonic motor. In particular, it is preferable that at least a part of the first or second lens group is a focusing lens group.

  The lens surface of the lens constituting the optical system of the present invention may be a spherical surface, a flat surface, or an aspheric surface. It is preferable that the lens surface is a spherical surface or a flat surface because lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to errors in lens processing and assembly adjustment can be prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. When the lens surface is aspheric, any of aspherical surfaces by grinding, a glass mold aspherical surface formed by molding glass into an aspherical surface, or a composite aspherical surface formed by forming resin on the glass surface into an aspherical surface An aspherical surface may be used. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

  In addition, the aperture stop SP of the optical system of the present invention is preferably disposed in the vicinity of the anti-vibration lens group, but the role may be substituted by a lens frame without providing a member as the aperture stop.

  Further, an antireflection film having a high transmittance in a wide wavelength range may be provided on the lens surface of the lens constituting the optical system of the present invention. Thereby, flare and ghost can be reduced and high contrast optical performance can be achieved.

  In the optical system of the present invention, the zoom ratio is about 3 to 20 times.

  Next, an optical apparatus provided with the optical system of the present invention will be described.

  FIG. 25 is a sectional view schematically showing a digital single-lens reflex camera provided with the optical system S of the present invention. In the digital single-lens reflex camera 1 shown in FIG. 25, light from an object (subject) (not shown) is collected by the optical system S and focused on the focusing plate 5 via the quick return mirror 3. The light imaged on the collecting plate 5 is reflected a plurality of times in the pentaprism 7 and guided to the eyepiece lens 9. Thus, the photographer can observe the object (subject) image as an erect image through the eyepiece 9.

  When a release button (not shown) is pressed by the photographer, the quick return mirror 3 is retracted out of the optical path, and the light of the object (subject) collected by the optical system S forms a subject image on the image sensor 11. . Thereby, the light from the object is picked up by the image pickup device 11 and stored in a memory (not shown) as an object image. In this way, the photographer can photograph an object with the camera 1.

  With the above configuration, the digital single-lens reflex camera 1 including the optical system S according to the present invention has a suitable anti-vibration function, can satisfactorily correct various aberrations, and can realize high optical performance. The camera 1 in FIG. 25 may be one that holds the photographic lens in a detachable manner or may be molded integrally with the photographic lens. The camera may be a single-lens reflex camera or a camera that does not have a quick return mirror or the like.

  Next, a method for manufacturing the optical system of the present invention will be described.

  26 and 27 are diagrams each schematically showing a method for manufacturing an optical system according to the present invention.

  The optical system manufacturing method of the present invention is a method for manufacturing an optical system having a first lens element and a second lens element, as shown in FIG. 26, and includes the following steps ST1 to ST4.

  Step ST1: The second lens element is composed of the first lens element and another lens element having a refractive power having the same sign as the refractive power of the first lens element.

  Step ST2: The first lens element and the second lens element are arranged so as to be shiftable so as to include a component in a direction perpendicular to the optical axis.

  Step ST3: The image plane correction is performed by shifting either the first lens element or the second lens element so as to include a component in a direction perpendicular to the optical axis.

  Step ST4: The following conditional expression (1) is satisfied.

(1) | fA |> | fB |
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element where fA and fB have the same reference numerals. As shown in FIG. 27, the method for manufacturing an optical system having a first lens element and a second lens element includes the following steps ST1 to ST4.

  Step ST1: The second lens element is composed of the first lens element and another lens element having a refractive power different from that of the first lens element.

  Step ST2: The first lens element and the second lens element are arranged so as to be shiftable so as to include a component in a direction perpendicular to the optical axis.

  Step ST3: The image plane correction is performed by shifting either the first lens element or the second lens element so as to include a component in a direction perpendicular to the optical axis.

  Step ST4: The following conditional expression (5) is satisfied.

(5) | fA | <| fB |
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element However, fA and fB are different from each other. According to the method of manufacturing an optical system of the present invention, An optical system having a suitable anti-vibration function can be manufactured.

S1 to S6 Optical system G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group G5 Fifth lens group SP Aperture stop I Image surface 1 Optical device 3 Quick return mirror 5 Concentration plate 7 Penta prism DESCRIPTION OF SYMBOLS 9 Eyepiece 11 Image pick-up element 21 Control part 23 Angular velocity sensor 25a, b Lens element 27 Driving device 29 Lens barrel 31 Imaging device

Claims (19)

Each having a first lens element and a second lens element that can be shifted to include a component perpendicular to the optical axis;
The second lens element is composed of the first lens element and another lens element,
An optical system that performs image plane correction by shifting the first lens element or the second lens element so as to include a component in a direction perpendicular to the optical axis. Each having a first lens element and a second lens element that can be shifted to include a component perpendicular to the optical axis;
2. The optical system according to claim 1, wherein in the second lens element, the first lens element and the other lens element have the same refractive power. The optical system according to claim 2, wherein the condition of the following formula is satisfied.
| FA |> | fB |
However,
| FA |: absolute value of the focal length of the first lens element | fB |: absolute value of the focal length of the second lens element where fA and fB have the same sign The optical system according to claim 2, wherein the condition of the following formula is satisfied.
0.24 <| fB | / | fA | <1.00
However,
| FA |: absolute value of the focal length of the first lens element | fB |: absolute value of the focal length of the second lens element where fA and fB have the same sign   A third lens element that can be shifted to include a component in a direction perpendicular to the optical axis is further included, and the third lens element has the same sign as the refractive power of the second lens element and the second lens element. A lens element having a refractive power, and shifting any one of the first lens element, the second lens element, or the third lens element so as to include a component perpendicular to the optical axis. 5. The optical system according to claim 1, wherein image plane correction is performed. The optical system according to claim 5, wherein the condition of the following formula is satisfied.
| FA |> | fB |> | fC |
However,
| FA |: absolute value of the focal length of the first lens element | fB |: absolute value of the focal length of the second lens element | fC |: absolute value of the focal length of the third lens element where fA, fB, and fC Is the same sign The optical system according to claim 5, wherein the condition of the following formula is satisfied.
0.24 <| fC | / | fA | <1.00
However,
| FA |: absolute value of the focal length of the first lens element | fC |: absolute value of the focal length of the second lens element where fA and fC have the same sign   The optical system according to claim 1, wherein the first and second lens elements have cemented lenses.   The optical system according to claim 5, wherein the third lens element has a cemented lens.   10. The apparatus according to claim 1, comprising at least four lens groups, wherein at least the first and second lens elements are included in any one of the four lens groups. The optical system described in 1.   In order from the object side, the zoom lens has a first lens group, a second lens group, a third lens group, and a fourth lens group, and at the time of zooming, the distance between the first lens group and the second lens group, The optical system according to claim 10, wherein an interval between the second lens group and the third lens group and an interval between the third lens group and the fourth lens group are changed. Each having a first lens element and a second lens element that can be shifted to include a component perpendicular to the optical axis;
2. The optical system according to claim 1, wherein in the second lens element, the first lens element and the other lens element have different signs of refractive power. The optical system according to claim 12, wherein the condition of the following formula is satisfied.
| FA | <| fB |
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element However, fA and fB have different signs The optical system according to claim 12, wherein the condition of the following formula is satisfied.
0.24 <| fA | / | fB | <1.00
However,
| FA |: Absolute value of the focal length of the first lens element | fB |: Absolute value of the focal length of the second lens element However, fA and fB have different signs   The optical system according to claim 12, wherein the first and second lens elements have cemented lenses.   16. The apparatus according to claim 12, comprising at least four lens groups, wherein the first and second lens elements are included in any one of the four lens groups. The optical system described.   In order from the object side, the zoom lens has a first lens group, a second lens group, a third lens group, and a fourth lens group, and at the time of zooming, the distance between the first lens group and the second lens group, The optical system according to claim 16, wherein an interval between the second lens group and the third lens group and an interval between the third lens group and the fourth lens group are changed.   An imaging apparatus comprising the optical system according to claim 1. A method of manufacturing an optical system having a first lens element and a second lens element,
The second lens element is composed of the first lens element and another lens element,
The first lens element and the second lens element are each arranged so as to be shiftable so as to include a component perpendicular to the optical axis,
The image plane correction is performed by shifting either the first lens element or the second lens element so as to include a component in a direction perpendicular to the optical axis. Method.

Images