JP3486541B2 - Inner focus optical system having vibration proof function and camera having the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of correcting blur of a photographed image due to vibration of an optical system using an inner focus at the time of focusing, that is, a so-called anti-vibration function. An inner focus type optical system having an anti-vibration function suitable for a photographic camera, a video camera, etc., which prevents deterioration of optical performance when the anti-vibration effect is exerted by moving in a direction orthogonal to the optical axis, and It relates to a camera having it.

[0002]

2. Description of the Related Art In recent years, many video cameras for consumer use have been proposed which have an image blur correction function for the purpose of preventing deterioration of image quality due to camera shake (vibration) during telephoto shooting by hand.

Generally, when a photographing system having a long focal length is used, it is difficult to suppress the vibration of the photographing system. When the photographing system tilts due to vibration, the photographed image is displaced according to the tilt angle and the focal length of the photographing system. Therefore, in the still image capturing device, there is a problem that the capturing time must be sufficiently short in order to prevent deterioration of image quality, and in the moving image capturing device, it becomes difficult to maintain the composition setting. There is a problem. Therefore, in such photographing, it is necessary to perform correction so that displacement of the photographed image, that is, blurring of the photographed image does not occur even when the photographing system tilts due to vibration.

Conventionally, as a method of correcting the blur of a photographed image, for example, in a video camera or the like, an electric correction method is widely adopted in which an effective area of an image pickup device is larger than a necessary screen range to electrically correct an image blur. Has been done.

According to Japanese Patent Laid-Open No. 61-223819, in a photographing system in which a refracting variable apex angle prism is arranged closest to the subject, the apex angle of the refracting variable apex prism is changed in response to the vibration of the photographing system. The image is deflected to stabilize the image.

[0006] Further, a lens group (moving lens group) in the optical system is moved in a direction orthogonal to the optical axis to correct the blur of a photographed image, as disclosed in, for example, JP-A-50-80147. JP-A-56-223819 and JP-A-7-
No. 270724, and Japanese Patent Laid-Open No. 8-201691.

On the other hand, there are various types of focusing in the taking lens, such as moving the entire taking lens,
Alternatively, a part of the photographing lens is moved. If the taking lens is a telephoto lens having a long focal length, the taking lens becomes large and heavy, and it is mechanically difficult to move the taking lens as a whole to perform focusing.

For this reason, in many telephoto lenses, some of the lens groups are moved for focusing. Among them, there are various ones that use the inner focus type in which a part of the central lens group in the relatively small and lightweight lens system other than the front lens group of the taking lens is moved to perform focusing. Proposed.

For example, in JP-A-55-147606, an inner focus type telephoto lens having a focal length of 300 mm and an F number of 2.8 is disclosed in JP-A-59-65820.
In JP-A-59-65821 and JP-A-59-65821, the focal length is 1
An inner focus type telephoto lens of 35 mm and an F number of about 2.8 is proposed.

In each of the inner focus type telephoto lenses proposed by these, the first group having a positive refractive power, the second group having a negative refractive power, and the third group having a positive refractive power are arranged in this order from the object side. It has three lens groups, and the second group is moved on the optical axis for focusing.

[0011]

However, there is a problem in that the above-mentioned electrical method as a method for correcting the blur of a photographed image cannot be applied to a silver halide photography camera. In addition, a prism with a variable prism apex angle is arranged on the object side of the optical system, the prism apex angle is changed according to the blur, and the method of correcting it is because the prism on the object side of the optical system is mounted. For a large-diameter optical system, the correction optical system and the driving device become large. Also, in terms of optical performance, there is a problem that chromatic aberration due to the prism action occurs at the time of correction, which makes it difficult to obtain a high-quality image required for silver halide photography.

Further, a method of displacing an image position by decentering a moving lens group of a part of an optical system to correct blurring is a method of appropriately selecting and arranging the moving lens group and Can be small.

However, in this method, it is necessary that the moving lens group is small and lightweight, and the displacement of a large image position is performed with a small amount of movement while correcting the eccentric aberration to prevent the deterioration of the image quality as much as possible. There was a problem that it was very difficult to satisfy

On the other hand, in the inner focus type, since the focusing lens group is small and lightweight, the operability is easy and the high speed operation is possible, and the entire lens system when focusing on an object at infinity and a near object is provided. There are advantages that the position of the center of gravity does not change and holding is easy.

On the other hand, when the inner focus type is adopted in the telephoto lens having a bright F number, the aberration variation at the time of focusing becomes large, and it is difficult to satisfactorily correct the aberration variation at this time, which causes the deterioration of the optical performance. Has become.

According to the present invention, some lens groups of the optical system are eccentrically driven in a direction perpendicular to the optical axis to displace (blurr) a photographed image.
When correcting the above, various eccentric aberrations are satisfactorily corrected by appropriately disposing each lens element, and a sufficiently large displacement correction (shake correction) is realized with a sufficiently small eccentric drive amount. The inner focus type, which can be downsized and has an anti-vibration function that satisfactorily corrects aberration fluctuations during focusing, over a wide range of object distances from infinity objects to short-distance objects while adopting the inner focus method An optical system and a camera having the same are provided.

[0017]

An inner focus type optical system having a vibration isolation function according to the present invention is arranged in order from the object side.
Inner focus having a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power, and moving the second lens group on the optical axis for focusing. In the optical system of the expression, the combined refracting power of the first lens group and the second lens group is positive, and the third lens group is, in order from the object side, the 31st group of positive refracting power and the negative refracting power. 32nd of power
Group, three lens groups of the 33rd group having a positive refractive power, and the 32nd group is moved in the direction orthogonal to the optical axis to displace the image forming position of the photographed image . Focal length of group
Fi, the focal length of the entire system is f, the 31st group, the 32nd group
The focal lengths of the lens group and the 33rd lens group are f31, f32, and f33 in order.
Then 0.3 <f1 / f <0.75 (3) 0.2 <| f2 / f | <0.7 (4) 0.1 <f / f3 <1.5 (5) 0.12 <f31 / f <0.5 (6) 0.05 <| f32 / f | <0.15 (7) 0.08 <f33 / f < 0.25 (8) is satisfied.

[0018]

1 to 16 are lens sectional views of Numerical Examples 1 to 16 to be described later of the present invention. L1 in the figure
Is the first group of positive refractive power, L2 is the second group of negative refractive power, L
The third group 3 has a positive refractive power.

The third lens unit L3 is the 31st lens unit L3 having a positive refractive power.
It has three lens groups, namely, a first lens unit L32 having a negative refractive power, and a third lens unit L33 having a positive refractive power. SP is an aperture stop, FL is an optical filter, and IP is an image plane.

In the present embodiment, focusing from an object at infinity to a close object is performed by moving the second lens unit to the image plane side as indicated by an arrow LF. Further, the correction (vibration compensation) of the captured image when the optical system vibrates is performed by making the 32nd lens unit L32 a movable lens unit (image displacement correction unit) and moving it in the direction orthogonal to the optical axis as indicated by the arrow LT. Is going.

In the optical system according to the present invention, focusing is performed by moving the second lens group, which has a small lens diameter and is lightweight and has a negative refractive power, with respect to the first lens group, on the optical axis, and the driving device thereof has a low torque. We have made available small things. Further, the combined refractive power of the first group and the second group is made positive. Then, the convergent light beam that has passed through the second lens unit is further converged by the 31st lens unit having a positive refractive power.
It is easy to reduce the lens diameter of the second group (image displacement correction group). Further, by arranging the 33rd lens unit having a positive refractive power, the refractive power of the 32nd lens unit having a negative refractive power is increased while maintaining a constant focal length of the entire lens system, and the eccentric movement of the 32nd lens unit causes less decentering movement. This facilitates a large displacement of the image position on the image plane (hereinafter, the relationship between the eccentricity amount and the image position displacement is referred to as image displacement sensitivity).

In the present embodiment, by setting each element as described above, for hand-held shooting of a video camera or a still camera having a telescopic optical system, or for shooting with an unstable tripod or monopod fixed. Image blurring that occurs is well corrected. Next, the technical meanings of the conditional expressions (3) to (8) are described.
And explain. Conditional expression (3) is defined by the bending of the first group with positive refractive power.
This is a condition for properly setting the folding force. Of conditional expression (3)
If the upper limit is exceeded and the refractive power of the first group becomes too small,
Since the action of the photo reflex system becomes weak, the total lens length
It's not good to be long. Also, the astringent effect is reduced
Since it is too large, the luminous flux entering the second lens group becomes thick.
However, the lens diameter of the second lens group becomes large. Also, a certain
In order to maintain the shooting angle of view, the refracting power of the second lens group becomes weak.
Therefore, the amount of focus movement increases. On the other hand, the lower limit
Beyond the value, the positive refractive power becomes too large and the spherical surface of higher order
Aberration occurs and it is difficult to correct it with other lens groups.
It will be difficult. Conditional expression (4) is a negative focus group.
With the condition for setting the refracting power of the second group of refracting power of
is there. Infinite to constant if the upper limit of conditional expression (4) is exceeded
The focus amount for the limited distance becomes large,
This will hinder the miniaturization of the system. Also, positive refractive power
Aberrations that occur in the first lens group, especially spherical aberration,
If it becomes impossible to correct in the second group of, and if the lower limit is exceeded,
Spherical aberration is overcorrected in the second lens group with negative refractive power.
As a result, good optical performance is maintained in the entire optical system.
It becomes difficult to carry. Conditional expression (5) is positive refractive power
This is a condition for properly setting the refractive power of the third lens group. Article
If the upper limit of condition (5) is exceeded, the back focus will become long.
It became difficult to downsize the whole optical system because it became too difficult
Therefore, it is difficult to correct the positive distortion that occurs in the first lens unit.
It On the other hand, if the lower limit is exceeded, spherical aberration and coma flare will occur.
The number of lenses in the third group increases to correct
As a result, it becomes difficult to downsize the entire optical system,
It is not good because the transmittance of the entire optical system deteriorates. Conditional expression
(6) to (8) properly adjust the refractive power of each lens unit of the third group.
Set and move the 32nd lens group in a direction substantially perpendicular to the optical axis to form an image.
Image displacement sensitivity is high,
This conditional expression is for ensuring good image performance.
If the value is out of the range of (6) to (8), the balance will be maintained.
Becomes difficult.

In this embodiment, the inner focus and the blurring of the photographed image are corrected in this way, and the optical constants of each lens group are appropriately set. As a result, the optical system as a whole is downsized, while the blurring of the captured image is corrected well, and the aberrations associated with the movement of the 32nd lens group in the direction orthogonal to the optical axis, that is, the eccentric coma aberration and the eccentric astigmatism. aberration,
The occurrence of eccentric aberrations such as eccentric field curvature is reduced, and good optical performance is obtained over the entire object distance.

In the present invention, it is preferable to satisfy at least one of the following conditions in order to further reduce the fluctuation of the eccentric aberration during image stabilization and obtain good optical performance over the entire object distance.

(A-1) The thirty-second lens group has a biconvex air lens. When the focal lengths of the air lens and the thirty-second lens group are fair and f32, respectively, 0.6 <fair / f32 <1.4 (1) is satisfied.

Conditional expression (1) is for forming an appropriately shaped air lens in the thirty-second lens group to obtain good image quality in both the reference state (image-less displacement state) and the image displacement state. When the value exceeds the numerical range of the conditional expression (1), it becomes difficult to balance the image quality in the reference state and the image displacement state.

(A-2) The 32nd group has a biconvex air lens, and the radius of curvature of the lens surface of the air lens on the object side and the radius of curvature of the lens surface on the image plane side are Rair1 and Rair2, respectively.

[0028]

[Equation 2] Is to be satisfied.

Conditional expression (2) is for appropriately setting the radii of curvature of the object-side lens surface and the image-side lens surface of the air lens to obtain better optical performance. When the range of the conditional expression (2) is exceeded, it becomes difficult to balance the image quality in the reference state and the image displacement state as in the conditional expression (1).

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

(A-3) Conditional Expression (3)
It is not necessary for (8) to satisfy all at the same time.
Even if an arbitrary number of conditional expressions are satisfied, the desired effect can be obtained.
To be

(A-4) The second group has a positive lens and a negative lens, and 7.5 <νn-νp, where the Abbe numbers of the materials of the positive lens and the negative lens are respectively νp and νn. <30 ... (9) is to be satisfied.

In the present invention, the second lens group is a positive lens having a strong convex surface facing the image side from the object side in order to reduce the weight of the lens group for reducing the focus driving torque and to reduce the aberration variation due to focusing. It is preferable to use a negative lens with a strong concave surface facing the surface side. Conditional expression (9) properly corrects the chromatic aberration variation in focus by appropriately setting the Abbe number of the material of the positive lens and the negative lens at this time. It is for doing.

If the refractive power of the second lens unit is increased in order to reduce the focus movement amount of the second lens unit, a plurality of negative lenses may be used.

(A-5) The thirty-second lens group is composed of, in order from the object side, a positive lens having two convex lens surfaces and a negative lens having two concave lens surfaces. This maintains good optical performance during image blur correction.

(A-6) The thirty-second lens group has, in order from the object side, a negative meniscus lens having a convex surface directed toward the object side, a positive meniscus lens having a convex surface directed toward the object side, and both lens surfaces having a concave surface. It consists of a negative lens. This maintains good optical performance during image blur correction.

(A-7) The second group is composed of two lenses, a positive lens and a negative lens. Thereby, the chromatic aberration variation at the time of focusing is well corrected.

(A-8) The 33rd group has a plurality of positive lenses. In order to achieve high image displacement sensitivity, it is preferable that the 33rd lens group has a certain degree of positive refractive power. If a lens system having a particularly large aperture is to be achieved, the 33rd lens group should have a plurality of positive lenses, which is particularly effective for correcting spherical aberrations of higher orders. Further, by further including at least one negative lens and a positive lens cemented with a positive lens, or a positive lens and a negative lens whose facing lens surfaces have similar radiuses of curvature, further improvement in chromatic aberration can be expected.

(A-9) The thirty-first lens unit has at least one positive lens and at least one negative lens in order to make it easy to correct the residual aberration generated by the first and second lens units by the lens unit closer to the image plane. It is desirable to have. Further, it is desirable that the 32nd lens group has a plurality of negative lenses and one or more positive lenses, and this makes it possible to suppress variation in chromatic aberration during image displacement.

(A-10) The first lens group is preferably composed of a plurality of positive lenses and one or more negative lenses. To obtain high image quality, the positive lens having both convex lens surfaces from the object side. It is preferable to have a positive lens having a strong convex surface on the object side, a biconcave lens, and a positive lens having a strong convex surface on the object side. More preferably, a meniscus-shaped negative lens having a convex surface directed toward the object side is preferably arranged behind these lenses.

(A-11) A flat plate glass or a transparent member or a lens having a weak refracting power on the object side of the lens system for protection of the lens surface and prevention of a change in image forming position due to lens expansion and contraction due to temperature change (protection (Members) should be arranged.

(A-12) The iris diaphragm (aperture diaphragm) may be arranged at any position of the lens system as long as the peripheral light flux in the used image range is not vignetted when the diaphragm is small, but the focus drive mechanism and the image displacement lens group movement Considering the arrangement space efficiency of mounting the mechanism and the electric circuit on the substrate, it is preferable to arrange the mechanism in the air between the second group and the third group or in the third group.

(A-13) It is desirable to arrange the optical filter in the air space between the image forming surface and the lens surface closest to the image surface in view of downsizing of the filter diameter and space efficiency.

(A-14) It is preferable to dispose the fixed diaphragm in the air space between the image forming surface and the lens surface closest to the image surface. According to this, it is possible to reduce the asymmetry of the peripheral light amount when the image is displaced.

(A-15) The above conditional expressions (1) to (9)
In the above, it is more preferable to set the numerical range as follows.

[0052]       0.7 <fair / f32 <1.2 (1a)

[0053]

[Equation 3] 0.4 <f1 / f <0.7 ... (3a) 0.25 <| f2 / f | <0.6 ... (4a) 0.1 <f / f3 <1.2 ... (5a) 0.15 <f31 / f <0.45 (6a) 0.06 <| f32 / f | <0.14 (7a) 0.11 <f33 / f <0.23 (8a) 8.0 <νn-νp <27 (9a) Next, numerical examples of the present invention will be shown. R in numerical examples
i is the radius of curvature of the i-th lens surface in order from the object side, D
i is the i-th lens thickness from the object side and the air gap, Ni
And νi are the refractive index and Abbe number of the glass of the i-th lens in order from the object side. In the numerical examples, the last two lens surfaces are glass blocks such as face plates and filters. Table 1 shows the relationship between the above-mentioned conditional expressions and various numerical values in the numerical examples.

[0054]

[Outer 1]

[0055]

[Outside 2]

[0056]

[Outside 3]

[0057]

[Outside 4]

[0058]

[Outside 5]

[0059]

[Outside 6]

[0060]

[Outside 7]

[0061]

[Outside 8]

[0062]

[Outside 9]

[0063]

[Outside 10]

[0064]

[Outside 11]

[0065]

[Outside 12]

[0066]

[Outside 13]

[0067]

[Outside 14]

[0068]

[Outside 15]

[0069]

[Outside 16]

[0070]

[Table 1]

[0071]

As described above, according to the present invention, when a lens group of a part of the optical system is eccentrically driven in the direction perpendicular to the optical axis to correct the displacement (blurring) of a photographed image, each lens element By properly disposing various types of eccentric aberrations, it is possible to satisfactorily correct various eccentric aberrations, and by realizing a sufficiently large displacement correction (shake correction) with a sufficiently small eccentric drive amount, it is possible to downsize the entire device, and An inner focus type optical system having an anti-vibration function that satisfactorily corrects aberration fluctuations during focusing over a wide range of object distances from an infinitely distant object to a short range object while adopting the focus type, and a camera having the same Can be achieved.

[Brief description of drawings]

FIG. 1 is a lens cross-sectional view of Numerical Example 1 of the present invention.

FIG. 2 is a lens cross-sectional view of Numerical Example 2 of the present invention.

FIG. 3 is a lens sectional view of Numerical Example 3 of the present invention.

FIG. 4 is a lens cross-sectional view of Numerical Example 4 of the present invention.

FIG. 5 is a lens cross-sectional view of Numerical Example 5 of the present invention.

FIG. 6 is a lens cross-sectional view of Numerical Example 6 of the present invention.

FIG. 7 is a lens cross-sectional view of Numerical Example 7 of the present invention.

FIG. 8 is a lens cross-sectional view of Numerical Example 8 of the present invention.

FIG. 9 is a lens cross-sectional view of Numerical Example 9 of the present invention.

FIG. 10 is a lens cross-sectional view of Numerical Example 10 of the present invention.

FIG. 11 is a lens cross-sectional view of Numerical Example 11 of the present invention.

FIG. 12 is a lens cross-sectional view of Numerical Example 12 of the present invention.

FIG. 13 is a lens cross-sectional view of Numerical Example 13 of the present invention.

FIG. 14 is a lens cross-sectional view of Numerical Example 14 of the present invention.

FIG. 15 is a lens cross-sectional view of Numerical Example 15 of the present invention.

FIG. 16 is a lens cross-sectional view of Numerical Example 16 of the present invention.

FIG. 17 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 1 of the present invention.

FIG. 18 is a lateral aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 1 of the present invention.

FIG. 19 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 1 of the present invention.

FIG. 20 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 2 of the present invention.

FIG. 21 is a lateral aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 2 of the present invention.

FIG. 22 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 2 of the present invention.

FIG. 23 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 3 of the present invention.

FIG. 24 is a lateral aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 3 of the present invention.

FIG. 25 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 3 of the present invention.

FIG. 26 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 4 of the present invention.

FIG. 27 is a lateral aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 4 of the present invention.

FIG. 28 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 4 of the present invention.

FIG. 29 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 5 of the present invention.

FIG. 30 is a lateral aberration diagram of the numerical example 5 of the present invention in a reference state (image-formation position undisplaced).

FIG. 31 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 5 of the present invention.

FIG. 32 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 6 of the present invention.

FIG. 33 is a lateral aberration diagram in a reference state (imaging position non-displacement) according to Numerical Example 6 of the present invention.

FIG. 34 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 6 of the present invention.

FIG. 35 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 7 of the present invention.

FIG. 36 is a lateral aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 7 of the present invention.

FIG. 37 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 7 of the present invention.

FIG. 38 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 8 of the present invention.

FIG. 39 is a lateral aberration diagram of the numerical example 8 of the present invention in the reference state (image-formation position undisplaced).

FIG. 40 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 8 of the present invention.

FIG. 41 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 9 of the present invention.

42 is a lateral aberration diagram in a reference state (image-formation position non-displacement) of Numerical Example 9 of the present invention. FIG.

FIG. 43 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 9 of the present invention.

FIG. 44 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 10 of the present invention.

FIG. 45 is a lateral aberration diagram of the numerical example 10 of the present invention in a reference state (image-formation position undisplaced).

46 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 10 of the present invention. FIG.

FIG. 47 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 11 of the present invention.

FIG. 48 is a lateral aberration diagram of the numerical example 11 of the present invention in a reference state (imaging position is not displaced).

FIG. 49 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 11 of the present invention.

FIG. 50 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 12 of the present invention.

FIG. 51 is a lateral aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 12 of the present invention.

52 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 12 of the present invention. FIG.

FIG. 53 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 13 of the present invention.

FIG. 54 is a lateral aberration diagram in a reference state (image-forming position non-displacement) of Numerical Example 13 of the present invention.

FIG. 55 is a lateral aberration diagram when an object at infinity is displaced in image position corresponding to an angle of view of 0.3 ° in Numerical Example 13 of the present invention.

FIG. 56 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 14 of the present invention.

FIG. 57 is a lateral aberration diagram of a numerical example 14 of the present invention in a reference state (image-formation position undisplaced).

FIG. 58 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 14 of the present invention.

FIG. 59 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 15 of the present invention.

FIG. 60 is a transverse aberration diagram of Numerical Example 15 of the present invention in a reference state (image-formation position undisplaced).

FIG. 61 is a lateral aberration diagram when an object at infinity is subjected to image position displacement corresponding to an angle of view of 0.3 ° in Numerical Example 15 of the present invention.

FIG. 62 is a longitudinal aberration diagram in a reference state (imaging position non-displacement) of Numerical Example 16 of the present invention.

FIG. 63 is a lateral aberration diagram of the numerical example 16 of the present invention in a reference state (image-formation position undisplaced).

FIG. 64 is a lateral aberration diagram when an object at infinity is displaced in image position corresponding to an angle of view of 0.3 ° in Numerical Example 16 of the present invention.

[Explanation of symbols]

L1 first group L2 second group L3 third group L31 31st group L32 32nd group L33 33rd group SP aperture stop IP image plane ΔS sagittal image plane ΔM meridional image plane d d line g g line

Continuation of the front page (56) Reference JP-A-9-218346 (JP, A) JP-A-9-197265 (JP, A) JP-A-7-261126 (JP, A) JP-A-8-122711 (JP , A) JP-A-8-122712 (JP, A) JP-A-8-122713 (JP, A) JP-A-8-304698 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G02B 13/00 G02B 9/00 G02B 27/64

Claims (10)

(57) [Claims] 1. A first lens group having a positive refracting power, a second lens group having a negative refracting power, and a third lens group having a positive refracting power are provided in this order from the object side, and the second lens group is used as a light source. In an inner focus type optical system that moves on-axis for focusing,
The combined refractive power of the first lens group and the second lens group is positive, and the third lens group includes, in order from the object side, the 31st group of positive refractive power, the 32nd group of negative refractive power, 33rd of positive refractive power
It has three lens groups, and the 32nd group is moved in the direction orthogonal to the optical axis to displace the image forming position of the photographed image .
, The focal length of the i-th lens group is fi, and the focal length of the entire system is
f, the focal lengths of the 31st lens group, the 32nd lens group, and the 33rd lens group in order
When f31, f32, and f33 are set to 0.3 <f1 / f <0.75 0.2 <| f2 / f | <0.7 0.1 <f / f3 <1.5 0.12 <f31 / f <0.5 0.05 <| f32 / f | <0.15 0.08 <f33 / f <0.25 An inner focus type optical system having a vibration-proof function, characterized in that: 2. The thirty-second lens group has a biconvex air lens, and 0.6 <fair / f32 <1 when the focal lengths of the air lens and the thirty-second lens group are fair and f32, respectively. 4. The inner focus type optical system having a vibration isolation function according to claim 1, wherein 3. The thirty-second lens group has a biconvex air lens, and the radiuses of curvature of the object-side and image-side lens surfaces of the air lens are Rair1 and Rair2, respectively. The inner focus type optical system having the image stabilizing function according to claim 1 or 2, characterized in that: Wherein said second lens group has a positive lens and a negative lens, vp respectively the Abbe number of the material of the positive lens and the negative lens, 7.5 when the νn <νn-νp <30 The inner focus type optical system having a vibration-proof function according to any one of claims 1 to 3 , wherein 5. Any of the claims 1 to 4, characterized in that the positive lens and the both lens surfaces of the first 32 group both lens surfaces is a convex surface in order from the object side is made from two negative lens concave An inner focus type optical system having a vibration isolation function according to item 1. Wherein said second 32 group of a meniscus-like positive lens having a negative lens, the object side convex surface of the meniscus form convex toward the object side in order from the object side, and a negative lens of which both surfaces are concave Claim 1 characterized by being formed.
4. An inner focus type optical system having a vibration isolation function according to any one of items 4 to 4 . Wherein said second lens group claim, characterized in that it consists of two positive lens and a negative lens
An inner focus type optical system having the image stabilizing function according to any one of 1 to 4 . Wherein said second 33 group of a plurality of internal focusing optical system of having any one of claims stabilization function of claims 1 to 4, characterized in that it has a positive lens. Wherein said displacement of the imaging position of the captured image of any one of claims 1 to 8, characterized in that to correct the blur of the photographed image caused when the optical system is vibrated Inner focus optical system with anti-vibration function. 10. A camera comprising an inner focus type optical system having a vibration isolation function according to any one of claims 1 to 9. Description: