JP6515480B2 - Variable magnification imaging optical system with anti-vibration function - Google Patents

Description

  The present invention relates to a variable magnification imaging optical system used for a still camera, a video camera and the like, and more particularly to a variable magnification imaging optical system having a narrow angle of view and further having a vibration isolation function.

In recent years, image processing optical systems used in digital still cameras etc. have been equipped with anti-vibration functions, and even with photography using a super telephoto lens, failures due to camera shake are reduced and the super telephoto lens becomes familiar It is coming. For this reason, an imaging optical system having a longer focal length and a narrow angle of view has been desired.

For example, Patent Document also describes an imaging optical system having a half angle of view of 2 degrees to 2.5 degrees at a telephoto end equivalent to a focal length of 500 mm to 600 mm in conversion to 35 mm.

JP, 2011-17912, A JP 2012-208434 A JP, 2011-186095, A JP, 2013-97322, A JP, 2014-126851, A

In an imaging optical system with a narrow angle of view and a long focus, it is first required to reduce the total length of the optical system compared to the focal length. The value obtained by dividing the total length of the optical system by the focal length is called a telephoto ratio, and it is desirable that this value be sufficiently smaller than 1. If the total length becomes longer in proportion to the focal length, it will be difficult to carry around, so in an optical system with a half angle of view of 2 to 2.5 degrees, it is desirable to keep the telephoto ratio below 0.7.

In order to reduce the telephoto ratio, a so-called telephoto type or telephoto type in which a lens unit of positive refracting power is disposed closest to the object side and a lens unit of negative refracting power is disposed closer to the image than the lens unit of positive refracting power It is effective to use a refractive power arrangement that is called, but when a lens unit of positive refractive power and negative refractive power are arranged with the stop from the object side, correction of lateral chromatic aberration is performed as the telephoto ratio is reduced. Have a weakness that makes it difficult.

Further, in the long focus imaging optical system, the diameter of the lens element becomes large as a whole especially on the object side, and the weight of the vibration reduction lens group tends to be heavy. As the weight of the anti-vibration lens unit increases, the actuator needs to be enlarged to increase the driving force of the actuator, which causes the lens barrel to be further enlarged. On the contrary, if the driving force of the actuator is insufficient, a problem occurs in the response, the correction accuracy of the camera shake decreases, and the problem of the practicability as the whole product appears.

Furthermore, in a long focus imaging optical system, the image blurring caused by camera shake also becomes large, and the displacement of the anti-vibration group in the direction orthogonal to the optical axis tends to be large. As the displacement of the antivibration group in the direction orthogonal to the optical axis increases, the size of the antivibration operating portion and the radial direction of the actuator increases, and the diameter of the entire lens barrel increases.

Therefore, it is necessary to reduce the light beam diameter as much as possible and set the weight of the antivibration group as light as possible, and the ratio of the displacement of the image in the orthogonal direction to the displacement of the antivibration group in the orthogonal direction of the optical axis, In order to reduce the amount of displacement of the necessary vibration isolation group, the

As in the case of the anti-vibration group, the weight and the displacement amount of the focus group tend to be large in the long focus lens, and the control of the light beam diameter and the securing of the focus sensitivity are problems.

The optical system described in Patent Document 1 well achieves shortening of the total optical length at the telephoto end, but it is difficult to suppress the diameter of the lens barrel because the diameter of the vibration reduction group is large and the vibration reduction coefficient is small. Further, the correction of the axial chromatic aberration is insufficient and there is a problem in the imaging performance.

The optical system described in Patent Document 2 has a telephoto ratio of about 0.77 at the telephoto end, but we would like to further shorten it. Furthermore, since the beam diameter of the focus group is particularly high at the wide angle end, a problem remains in the focus group weight.

The optical system described in Patent Document 3 corresponds to an image circle having a radius of about 11 mm and has a telephoto ratio of 0.65 and an extremely short total optical length, but no mention is made of vibration reduction.

Although the optical system described in Patent Document 4 has a very short total optical length with a telephoto ratio of about 0.65, the diameter of the vibration isolation group is too large, and even though the vibration isolation group has a single-piece configuration, weight reduction is not possible. It is enough. In addition, the correction of the chromatic aberration of magnification at the telephoto end is also insufficient and there is a problem in the performance.

The optical system described in Patent Document 5 has a very short total optical length with a telephoto ratio of about 0.65 and a reduced diameter of the vibration reduction group, but the vibration reduction coefficient is small and the vibration reduction group movement amount at the telephoto end In particular, the fluctuation of coma due to the shift of the anti-vibration group is large, and the performance at the time of anti-vibration is not sufficient.

The present invention has been made in view of such a situation, and in a variable power imaging optical system having a large image circle at a telephoto end half angle of view of 2 degrees and a long focal length at a telephoto end, the total length is suppressed. It is an object of the present invention to provide a high performance variable magnification imaging optical system having a vibration isolation function, in which the weight of the vibration isolation group is suppressed.

Then, in order to solve the above-mentioned subject, invention of Claim 1 is,
From the object side,
A first lens group of positive refractive power,
A second lens unit of negative refractive power,
It consists of a rear lens group of positive refractive power as a whole throughout the magnification variation,
The rear lens unit is arranged in order from the object side
The third lens group having a positive refractive power, the fourth lens group having a positive refractive power, and the fifth lens group having a negative refractive power
Or a third lens group of positive refractive power, a fourth lens group of positive refractive power, a fifth lens group of negative refractive power, and a sixth lens group of negative refractive power,
The lens groups are separated by an air gap, and the air gap between the lens groups changes during zooming.
The rear lens group consists of at least two lens groups that move in independent trajectories during zooming,
The second lens group is composed of, in order from the object side, a 2a group of negative refractive power and a 2b group of negative refractive power, and performs image stabilization by displacing the 2b group in a direction orthogonal to the optical axis,
The group 2a has a lens component with positive refractive power on the object side,
According to another aspect of the present invention, there is provided a variable magnification imaging optical system having a vibration reduction function, which satisfies the following conditional expressions (1) and (2).
(1) 0.70 <| LT2a / f2a | <0.85
(2)-0.025 <dpp2a / | f2a | <-0.005
However,
LT2a is the distance from the most object side surface of the 2a group to the image side focal point of the 2a group,
f2a is the focal length of the 2a group,
dpp2a is the distance from the object-side principal point of the 2a group to the image-side principal point,
It is.

The invention according to claim 2 is
The variable magnification imaging optical system having an image stabilizing function according to claim 1, wherein the second lens group is fixed to an image plane at the time of magnification variation.

The invention according to claim 3 is
The variable power imaging optical system having a vibration reduction function according to claim 1 or 2, wherein the rear lens group is provided with a third lens group having a positive refractive power on the most object side.

The invention according to claim 4 is
The rear lens unit has a lens unit of negative refractive power on the most image side,
4. The variable power imaging with the image stabilizing function according to claim 3, wherein during focusing, all or part of any lens group except the third lens group in the rear lens group is moved. It is an optical system .

According to the present invention, in the variable magnification imaging optical system having a large image circle at a telephoto end half angle of view of 2 degrees and a long focal length at a telephoto end, the weight of the vibration reduction group is suppressed while suppressing the overall length. It is possible to provide a variable magnification imaging optical system having a vibration isolation function.

It is a lens block diagram which concerns on Example 1 of the imaging optical system of this invention. 5 is a longitudinal aberration diagram of the imaging optical system of Example 1 at the wide-angle end shooting distance infinity. FIG. FIG. 7 is a longitudinal aberration diagram of the imaging optical system of Example 1 at an intermediate telephoto shooting distance at infinity. FIG. 6 is a longitudinal aberration diagram of the imaging optical system of Example 1 at an imaging distance at infinity at an telephoto end. FIG. 7 is a lateral aberration diagram of the imaging optical system of Example 1 at the wide-angle end shooting distance infinity. 5 is a lateral aberration diagram of the imaging optical system of Example 1 at the middle telephoto shooting distance at infinity. FIG. 5 is a lateral aberration diagram of the imaging optical system of Example 1 at an infinite photographing distance at a telephoto end. FIG. FIG. 6 is a lateral aberration diagram at the time of image stabilization of 0.3 ° at an imaging distance of infinity at the wide angle end of the imaging optical system of Example 1; FIG. 7 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at infinity shooting distance of middle telephoto of the imaging optical system of Example 1. 5 is a lateral aberration diagram at the time of image stabilization at 0.3 ° in the case of shooting distance at infinity at the telephoto end of the imaging optical system of Example 1; It is a lens block diagram which concerns on Example 2 of the imaging optical system of this invention. FIG. 7 is a longitudinal aberration diagram of the imaging optical system of Example 2 at the wide-angle end shooting distance infinity. FIG. 7 is a longitudinal aberration diagram of the imaging optical system of the second embodiment at a medium telephoto shooting distance at infinity. FIG. 7 is a longitudinal aberration diagram of the imaging optical system of Example 2 at the shooting distance infinity at the telephoto end. FIG. 7 is a lateral aberration diagram of the imaging optical system of Example 2 at the wide-angle end shooting distance infinity. FIG. 7 is a lateral aberration diagram of the imaging optical system of Example 2 at an intermediate telephoto shooting distance at infinity. FIG. 7 is a lateral aberration diagram of the imaging optical system of Example 2 at the shooting distance infinity at the telephoto end. FIG. 7 is a lateral aberration diagram at the time of image stabilization at 0.3 ° in the infinite imaging distance at the wide angle end of the imaging optical system of Example 2. FIG. 7 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at infinity shooting distance of middle telephoto of the imaging optical system of Example 2. FIG. 7 is a lateral aberration diagram at the time of image stabilization at 0.3 ° in the infinite imaging distance of the telephoto end of the imaging optical system of Example 2; It is a lens block diagram which concerns on Example 3 of the imaging optical system of this invention. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 3 at the wide-angle end shooting distance infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 3 at the middle telephoto shooting distance at infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 3 at an imaging distance at infinity at an telephoto end. FIG. 16 is a lateral aberration diagram of the imaging optical system at the wide-angle end at a shooting distance of infinity of the third embodiment. FIG. 16A is a lateral aberration diagram of the imaging optical system of Example 3 at an intermediate telephoto shooting distance at infinity. FIG. 16 is a lateral aberration diagram at a shooting distance at infinity of a telephoto end of the imaging optical system of Example 3; FIG. 13 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at the shooting distance infinity at the wide angle end of the image forming optical system of Example 3; FIG. 16 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at infinity shooting distance of middle telephoto of the imaging optical system of Example 3. FIG. 16 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at the shooting distance infinity of the telephoto end of the imaging optical system of Example 3; It is a lens block diagram which concerns on Example 4 of the imaging optical system of this invention. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 4 at the wide-angle end shooting distance infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 4 at an intermediate telephoto shooting distance at infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 4 at an imaging distance at infinity at an telephoto end. FIG. 16 is a lateral aberration diagram of the imaging optical system of Example 4 at the wide-angle end shooting distance infinity. FIG. 16A is a lateral aberration diagram of the imaging optical system of Example 4 at an intermediate telephoto shooting distance at infinity. FIG. 16 is a lateral aberration diagram of the imaging optical system of Example 4 at the shooting distance infinity at the telephoto end. FIG. 16 is a lateral aberration diagram at a 0.3 ° image stabilization time at an infinity imaging distance at the wide angle end of the imaging optical system of Example 4. FIG. 18B is a lateral aberration diagram at the time of 0.3 ° anti-vibration at infinity shooting distance of middle telephoto of the imaging optical system of Example 4. FIG. 18B is a lateral aberration diagram at the time of 0.3 ° anti-vibration at the shooting distance infinity of the telephoto end of the imaging optical system of Example 4; It is a lens block diagram which concerns on Example 5 of the imaging optical system of this invention. FIG. 18 is a longitudinal aberration diagram of the imaging optical system of Example 5 at the wide-angle end shooting distance infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 5 at the middle telephoto shooting distance at infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 5 at the shooting distance infinity of the telephoto end. FIG. 16 is a lateral aberration diagram at a shooting distance of infinity at the wide angle end of the imaging optical system of Example 5; FIG. 16A is a lateral aberration diagram of the imaging optical system of Example 5 at an intermediate telephoto shooting distance at infinity. FIG. 16 is a lateral aberration diagram at a shooting distance at infinity of a telephoto end of the imaging optical system of Example 5; FIG. 21 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at the shooting distance infinity at the wide angle end of the image forming optical system of Example 5; FIG. 18E is a lateral aberration diagram at the time of 0.3 ° anti-vibration of the image pickup optical system at the intermediate telephoto shooting distance at infinity when the image forming optical system of Example 5 is used. FIG. 21 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at the shooting distance infinity of the telephoto end of the imaging optical system of Example 5; It is a lens block diagram which concerns on Example 6 of the imaging optical system of this invention. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 6 at the wide-angle end shooting distance infinity. FIG. 21 is a longitudinal aberration diagram of the imaging optical system of Example 6 at the middle telephoto shooting distance at infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 6 at the shooting distance infinity of the telephoto end. FIG. 21 is a lateral aberration diagram at a shooting distance of infinity at the wide angle end of the imaging optical system of Example 6; FIG. 18A is a lateral aberration diagram of the imaging optical system of Example 6 at the intermediate telephoto shooting distance at infinity. FIG. 18 shows lateral aberration diagrams of the imaging optical system at the telephoto end of the imaging optical system of Example 6 at infinity. FIG. 21 is a lateral aberration diagram at the time of image stabilization at 0.3 ° in the infinite imaging distance at the wide angle end of the imaging optical system of Example 6. It is a lateral aberration figure at the time of 0.3-degree anti-vibration in the photography distance at infinity of the middle telephoto of the imaging optical system of Example 6. It is a lateral aberration figure at the time of 0.3-degree anti-vibration of imaging distance at the telephoto end of the image forming optical system of Example 6 at infinity. It is a lens block diagram which concerns on Example 7 of the imaging optical system of this invention. FIG. 18 is a longitudinal aberration diagram of the imaging optical system of Example 7 at the wide-angle end shooting distance infinity. FIG. 16 is a longitudinal aberration diagram of the imaging optical system of Example 7 at the middle telephoto shooting distance at infinity. FIG. 18 is a longitudinal aberration diagram of the imaging optical system of Example 7 at an imaging distance at infinity at an telephoto limit. FIG. 16 is a lateral aberration diagram of the imaging optical system of Example 7 at the wide-angle end shooting distance infinity. FIG. 18 shows lateral aberration diagrams of the imaging optical system of Example 7 at an intermediate telephoto shooting distance at infinity. FIG. 18 shows lateral aberration diagrams of the imaging optical system at the telephoto end of the imaging optical system of Example 7 at infinity. FIG. 21 is a lateral aberration diagram at the time of 0.3 ° anti-vibration at the shooting distance infinity at the wide angle end of the imaging optical system of Example 7; It is a lateral aberration figure at the time of 0.3-degree anti-vibration of the imaging distance at middle telephoto of the imaging optical system of Example 7 at infinity. It is a lateral aberration figure at the time of 0.3-degree anti-vibration of imaging distance at the telephoto end of the imaging optical system of Example 7 at infinity. It is a lens block diagram which concerns on Example 8 of the imaging optical system of this invention. FIG. 18 is a longitudinal aberration diagram of the imaging optical system of Example 8 at the shooting distance infinity at the wide angle end. 60 is a longitudinal aberration diagram of the imaging optical system of Example 8 at an intermediate telephoto shooting distance at infinity. FIG. It is a longitudinal aberration figure in the photography distance infinity of the telephoto end of the imaging optical system of Example 8 infinite. FIG. 20 shows lateral aberration at the shooting distance at infinity at the wide angle end of the imaging optical system of Example 8. 60 is a lateral aberration diagram of the imaging optical system of Example 8 at the intermediate telephoto shooting distance at infinity. FIG. It is a transverse aberration figure in the photography distance infinite distance of the telephoto end of the image forming optical system of Example 8. It is a lateral aberration figure at the time of 0.3 degree anti-vibration of imaging distance at the wide-angle end of an image forming optical system of Example 8 at infinity. It is a lateral aberration figure at the time of 0.3-degree anti-vibration of the imaging distance at middle telephoto of the imaging optical system of Example 8 at infinity. It is a lateral aberration figure at the time of 0.3-degree anti-vibration of imaging distance at the telephoto end of the image forming optical system of Example 8 at infinity.

The variable magnification imaging optical system provided with the image stabilization function of the present invention is an object as shown in each lens configuration diagram shown in FIGS. 1, 11, 21, 31, 31, 41, 51, 61, and 71. It consists of a first lens group of positive refractive index, a second lens group of negative refractive power, and at least two rear lens groups following the second lens group in order from the side, and as a whole is positive over the entire zoom range It consists of a back lens group of refractive power.

The lens units are separated by an air gap, and the distance between the lens units changes during zooming. The second lens unit includes, in order from the object side, a 2a unit having a negative refractive power and a 2b unit having a negative refractive power, and performs image stabilization by displacing the 2b group in a direction orthogonal to the optical axis. The group 2a has a lens component of positive refractive power on the most object side, and is configured to satisfy a predetermined conditional expression.

In order to suppress the total length while increasing the focal length at the telephoto end, the first lens unit of positive refractive power and the second lens unit of negative refractive power are arranged in order from the object side to arrange the telephoto type refractive power Configured.

The zooming from the wide-angle end to the telephoto end is mainly performed by increasing the distance between the first lens unit and the second lens unit.

In addition, the distance between the second lens unit and the rear lens unit decreases with zooming from the wide-angle end to the telephoto end, and the refractive power of the combined system of the second lens unit and the rear lens unit changes in the negative direction. By this action, the telephoto type refractive power arrangement formed by the combined system of the first lens group, the second lens group and the rear lens group becomes stronger from the wide angle end toward the telephoto end. At the wide-angle end, the total length of the optical system is relatively long with respect to the combined focal length of the entire system, and at the telephoto end, the total length of the optical system is relatively short with respect to the combined focal length of the entire system. Can be suppressed.

The second lens unit has a light beam diameter significantly lower than that of the first lens unit, and is suitable for reducing the weight of the vibration control unit by using it as a vibration control unit. Furthermore, the second lens group is divided into 2a and 2b groups in order from the object side, and only the 2b group disposed on the image side and having a smaller beam diameter is used for image stabilization to further reduce the weight of the image stabilizing group. Suitable.

A lens component of positive refractive power is disposed on the most object side of the 2a group. In order to obtain negative refractive power as a whole of the 2a group, a lens component of negative refractive power is inevitably disposed on the image side. With such an arrangement, the 2a group itself is configured to have a telephoto type refractive power arrangement. Since the axial beam diameter emitted from the 2a group can be reduced by the effect of this arrangement while the axial beam diameter emitted from the 2a group can be reduced while shortening the overall length of the entire optical system, the vibration group can be reduced. Is effective in reducing the weight of

The shortening of the total length of the entire optical system can also be achieved by increasing the refracting powers of the portion with positive refractive power at the front and the portion with negative refractive power at the rear, respectively. However, as the refractive power of each group becomes strong, the occurrence of aberration in each group becomes large. In particular, by strengthening the refracting power of the positive group before the stop and the negative group after the stop, it is difficult to correct lateral chromatic aberration or to suppress fluctuations during zooming, making it difficult to maintain the overall system performance. .

It is effective to maintain performance while shortening the overall length by adopting a configuration with a small telephoto ratio in the 2a group in which no aperture is sandwiched between.

The conditional expression (1) defines the telephoto ratio of the 2a group, and shows a desirable range for shortening the entire optical system and reducing the weight of the vibration reduction group.

If the upper limit of conditional expression (1) is exceeded and the telephoto ratio of group 2a is increased, shortening of the total length and suppression of the beam diameter of group 2b are insufficient, and weight reduction of the vibration reduction group is also insufficient.

If the lower limit of conditional expression (1) is exceeded and the telephoto ratio of group 2a decreases, the effects of shortening the total length and suppressing the light beam diameter increase, but the refractive power of the lens component with positive refractive power on the object side becomes strong As a result, astigmatism fluctuation caused by lens tilt tends to be large, and performance degradation due to manufacturing error becomes large.

The effect of the present invention is achieved more reliably by setting the upper limit of conditional expression (1) to 0.83, further to 0.82, and the lower limit of conditional expression (1) to 0.71 and further to 0.72. can do.

The conditional expression (2) defines the distance between the two principal points of the 2a group, and indicates a desirable range for shortening the entire optical system and reducing the weight of the vibration reduction group.

The overall length of the entire optical system can be shortened by positioning the object-side principal point of the group 2a on the image side with respect to the image-side principal point. In addition, since the axial ray diameter can be reduced in a shorter section, the ray diameter of the 2b group can be suppressed while shortening the total length.

When the value exceeds the upper limit of the conditional expression (2), the object-side principal point is positioned on the object side with respect to the image-side principal point, and the total length shortening and the suppression of the beam diameter are insufficient.

If the lower limit of conditional expression (2) is exceeded, the effects of shortening the total length and suppressing the ray diameter become high, but the refractive power of the lens component of positive refractive power on the most object side becomes too strong and non-tilt with lens tilt The variation of the point aberration tends to be large, and the performance deterioration due to the manufacturing error becomes large.

The effect of the present invention can be obtained by setting the upper limit of conditional expression (2) to -0.008, further -0.010, and the lower limit of conditional expression (2) to -0.022 and further -0.020. It can be achieved more reliably.

In the variable magnification imaging optical system having a vibration isolation function of the present invention, it is desirable that the second lens group be fixed to the image plane at the time of zooming. This is because it is necessary to connect control wiring to the second lens group in order to include the anti-vibration group. When the second lens group moves, connection is made by the flexible wiring, and a space for bending the flexible wiring and retreating is required in order to prevent excessive stress from being applied to the flexible wiring as the second lens group moves. In order to secure the space, it is difficult to miniaturize the entire lens barrel.

In the variable magnification imaging optical system provided with the anti-vibration function of the present invention, it is desirable to provide the third lens group of positive refractive power on the most object side of the rear lens group. By bringing the third lens unit of positive refractive power closer to the second lens unit of negative refractive power at the telephoto end, the negative refraction of the combined system of the second lens unit and the third lens unit at the telephoto end The force can be increased, the total optical length at the telephoto end can be shortened, and the movement amount of the first lens unit can be suppressed.

In the variable magnification imaging optical system having a vibration isolation function of the present invention, it is desirable to move all or part of any lens group except the third lens group in the rear lens group in focusing. .

In a long focus lens, the defocus amount for focusing at a short distance becomes large. In view of the improvement in the speed of driving the autofocus, first, two points are achieved: the focusing lens unit is light in weight, and secondly, the moving amount of the image plane with respect to the unit moving amount of the focusing lens unit is large. Is desirable.

In order to use a portion close to the object side in the long focus optical system for focusing, the outer diameter is too large and the weight can not be suppressed at all. In the variable magnification imaging optical system of the present invention, the light beam is converged by the first lens group, diverged by the second lens group, and converged by the third lens group. Therefore, in the case of a lens group further rearward than the third lens group in the rear lens group, the luminous flux is sufficiently converged, and sufficient weight reduction is possible.

Further, in order to shorten the entire optical system, it is desirable that the most image-side lens group of the optical system has a strong negative refractive power. Due to this strong negative refractive power, the imaging magnification of this most image side lens group is increased. Therefore, the image plane movement amount per unit movement amount of the lens group is the whole or a part of the lens group on the most image side, or the whole or a part of the lens group on the object side than the lens group on the most image side. It is easy to get bigger.

From these properties, it is desirable to perform focusing with all or part of any lens group except the third lens group located closest to the object side in the rear lens group.

Next, the lens configuration of an embodiment according to the image forming optical system of the present invention will be described.
In the following description, lens configurations are described in order from the object side to the image side.

FIG. 1 is a lens configuration diagram of an image forming optical system according to a first embodiment of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, and The fifth lens unit G5 has a negative refractive power.

The composite system from the third lens group G3 to the fifth lens group G5 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a negative meniscus lens L1 having a convex surface facing the object side, a biconvex lens L2, and a positive meniscus lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group consists of a doublet lens L7 and a cemented lens consisting of a double concave lens L8 and a double convex lens L9.

The third lens group G3 includes a biconvex lens L10, a cemented lens including a biconvex lens L11 and a biconcave lens L12, a positive meniscus lens L13 having a convex surface on the object side, and a negative meniscus lens L14 having a convex surface on the object side. It consists of

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet including a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a positive meniscus lens L17 having a convex surface facing the object side. The fourth lens group G4 moves toward the object side during focusing from infinity to near distance.

The fifth lens group G5 is composed of a negative meniscus lens L18 with a convex surface facing the object side, and a cemented lens consisting of a biconcave lens L19 and a biconvex lens L20.

FIG. 11 is a lens configuration diagram of an image forming optical system according to a second embodiment of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, and The fifth lens unit G5 has a negative refractive power.

The composite system from the third lens group G3 to the fifth lens group G5 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a cemented lens composed of a negative meniscus lens L1 having a convex surface facing the object side and a biconvex lens L2, and a plano-convex lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group consists of a doublet lens L7 and a cemented lens consisting of a double concave lens L8 and a double convex lens L9.

The third lens group G3 includes a biconvex lens L10, a cemented lens including a biconvex lens L11 and a biconcave lens L12, a positive meniscus lens L13 having a convex surface on the object side, and a negative meniscus lens L14 having a convex surface on the object side. It consists of

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet including a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a positive meniscus lens L17 having a convex surface facing the object side. The fourth lens group G4 moves toward the object side during focusing from infinity to near distance.

The fifth lens group G5 is composed of a negative meniscus lens L18 with a convex surface facing the object side, and a cemented lens consisting of a biconcave lens L19 and a biconvex lens L20.

FIG. 21 is a lens configuration diagram of an image forming optical system according to a third embodiment of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, and The fifth lens unit G5 has a negative refractive power.

The composite system from the third lens group G3 to the fifth lens group G5 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a negative meniscus lens L1 having a convex surface facing the object side, a biconvex lens L2, and a positive meniscus lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group consists of a doublet lens L7 and a cemented lens consisting of a double concave lens L8 and a double convex lens L9.

The third lens group G3 includes a biconvex lens L10, a cemented lens including a biconvex lens L11 and a biconcave lens L12, a positive meniscus lens L13 having a convex surface on the object side, and a negative meniscus lens L14 having a convex surface on the object side. It consists of

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet including a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a positive meniscus lens L17 having a convex surface facing the object side. The fourth lens group G4 moves toward the object side during focusing from infinity to near distance.

The fifth lens group G5 is composed of a negative meniscus lens L18 with a convex surface facing the object side, and a cemented lens consisting of a biconcave lens L19 and a biconvex lens L20.

FIG. 31 is a lens configuration diagram of an image forming optical system according to a fourth embodiment of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, and The fifth lens unit G5 has a negative refractive power.

The composite system from the third lens group G3 to the fifth lens group G5 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a cemented lens composed of a negative meniscus lens L1 having a convex surface facing the object side and a biconvex lens L2, and a plano-convex lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group includes a doublet lens L7, and a cemented lens including a double concave lens L8 and a positive meniscus lens L9 having a convex surface facing the object side.

The third lens group G3 includes a biconvex lens L10, a cemented lens including a biconvex lens L11 and a biconcave lens L12, a positive meniscus lens L13 having a convex surface on the object side, and a negative meniscus lens L14 having a convex surface on the object side. It consists of

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet including a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a positive meniscus lens L17 having a convex surface facing the object side.

The fifth lens group G5 is composed of a cemented lens consisting of a negative meniscus lens L18 having a convex surface facing the object side and a positive meniscus L20 having a biconcave lens L19 and a convex surface facing the object side.
The fifth lens group G5 moves toward the image side during focusing from infinity to near distance.

FIG. 41 is a lens configuration diagram of an image forming optical system according to a fifth embodiment of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, and The fifth lens unit G5 has a negative refractive power.

The composite system from the third lens group G3 to the fifth lens group G5 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a cemented lens composed of a negative meniscus lens L1 having a convex surface facing the object side and a biconvex lens L2, and a plano-convex lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group includes a doublet lens L7, and a cemented lens including a double concave lens L8 and a positive meniscus lens L9 having a convex surface facing the object side.

The third lens group G3 includes a biconvex lens L10, a cemented lens including a biconvex lens L11 and a biconcave lens L12, a positive meniscus lens L13 having a convex surface on the object side, and a negative meniscus lens L14 having a convex surface on the object side. It consists of

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet including a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a positive meniscus lens L17 having a convex surface facing the object side.

The fifth lens group G5 is composed of a cemented lens consisting of a negative meniscus lens L18 having a convex surface facing the object side, and a positive meniscus lens L20 having a biconcave lens L19 and a convex surface facing the object side. The fifth lens group G5 moves toward the image side during focusing from infinity to near distance.

FIG. 51 is a lens configuration diagram of an image forming optical system according to a sixth embodiment of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, and The fifth lens unit G5 has a negative refractive power.

The composite system from the third lens group G3 to the fifth lens group G5 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a cemented lens composed of a negative meniscus lens L1 having a convex surface facing the object side and a biconvex lens L2, and a plano-convex lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group includes a doublet lens L7, and a cemented lens including a double concave lens L8 and a positive meniscus lens L9 having a convex surface facing the object side.

The third lens group G3 includes a biconvex lens L10, a cemented lens including a biconvex lens L11 and a biconcave lens L12, a positive meniscus lens L13 having a convex surface on the object side, and a negative meniscus lens L14 having a convex surface on the object side. It consists of

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet of a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a biconvex lens L17.

The fifth lens group G5 is composed of a 5a group of negative refractive power and a 5b group of negative refractive power. The 5a group includes a negative meniscus lens L18 having a convex surface on the object side and a positive meniscus lens L19 having a convex surface on the object side.

The 5b group includes a cemented lens including a biconcave lens L20 and a positive meniscus lens L21 having a convex surface facing the object side. The group 5b moves to the image side during focusing from infinity to near distance.

FIG. 61 is a lens configuration diagram of the imaging optical system of Example 7 of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, negative And a sixth lens group G6 having a negative refractive power.

The composite system from the third lens group G3 to the sixth lens group G6 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a cemented lens composed of a negative meniscus lens L1 having a convex surface facing the object side and a biconvex lens L2, and a plano-convex lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group includes a doublet lens L7, and a cemented lens including a double concave lens L8 and a positive meniscus lens L9 having a convex surface facing the object side.

The third lens group G3 is a cemented lens consisting of a biconvex lens L10, a biconvex lens L11 and a negative meniscus lens L12 convex on the image side, a positive meniscus lens L13 convex on the object side, and a convex surface on the object side And a negative meniscus lens L14 directed thereto.

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet of a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a biconvex lens L17.

The fifth lens group G5 is composed of a negative meniscus lens L18 with a convex surface facing the object side and a positive meniscus lens L19 with a convex surface facing the object side. The fifth lens group G5 moves toward the image side during focusing from infinity to near distance.

The sixth lens group G6 is composed of a doublet including a biconcave lens L20 and a positive meniscus lens L21 having a convex surface facing the object side.

FIG. 71 is a lens configuration diagram of the imaging optical system of Example 8 of the present invention.

From the object side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power, a fourth lens group G4 of positive refractive power, and The fifth lens unit G5 has a negative refractive power.

The composite system from the third lens group G3 to the fifth lens group G5 corresponds to the rear lens group Gr.

The first lens group G1 is composed of a negative meniscus lens L1 having a convex surface facing the object side, a biconvex lens L2, and a positive meniscus lens L3 having a convex surface facing the object side.

The second lens unit is composed of, in order from the object side, a 2a unit of negative refractive power and a 2b unit of negative refractive power, and performs vibration isolation by displacing only the 2b unit in a direction orthogonal to the optical axis.

The 2a group includes a positive meniscus lens L4 having a convex surface facing the object side, and a cemented lens including a biconvex lens L5 and a biconcave lens L6.

The 2b group consists of a doublet lens L7 and a cemented lens consisting of a double concave lens L8 and a double convex lens L9.

The third lens group G3 includes a biconvex lens L10, a cemented lens including a biconvex lens L11 and a biconcave lens L12, a positive meniscus lens L13 having a convex surface on the object side, and a negative meniscus lens L14 having a convex surface on the object side. It consists of

An aperture stop is provided on the image side of the third lens unit, and moves integrally with the third lens unit as the magnification changes.

The fourth lens group G4 is composed of a doublet including a biconvex lens L15 and a negative meniscus lens L16 having a convex surface facing the image side, and a positive meniscus lens L17 having a convex surface facing the object side. The fourth lens group G4 moves toward the object side during focusing from infinity to near distance.

The fifth lens group G5 is composed of a negative meniscus lens L18 with a convex surface facing the object side, and a cemented lens consisting of a biconcave lens L19 and a biconvex lens L20.

Specific numerical data of each of the embodiments of the image forming optical system of the present invention described above will be shown below.

In [Surface Data], the surface number is the lens surface number or aperture stop number counted from the object side, r is the radius of curvature of each surface, d is the distance between each surface, and nd is the refractive index for d line (wavelength 587.56 nm) , Vd indicate Abbe numbers for d line.

The (diaphragm) attached to the surface number indicates that the aperture stop is located at that position. The radius of curvature for a flat or aperture stop is filled with ∞ (infinity). Also, BF represents back focus.

[Various data] show values such as focal length in each shooting distance state.

[Variable interval data] shows values of the variable interval and the BF in each shooting distance state.

[Lens group data] indicates the surface number closest to the object side constituting each lens group and the combined focal length of the entire group.

In all the following specification values, the unit of focal length f, radius of curvature r, inter-lens surface distance d, and other lengths described is millimeter (mm) unless otherwise specified. The system is not limited to this, as the same optical performance can be obtained in the proportional expansion and the proportional reduction.

  In addition, a list of corresponding values of the conditional expressions in each of these examples is shown.

  Further, in the aberration diagrams corresponding to the respective examples, d, g and C respectively represent d line, g line and C line, and ΔS and ΔM respectively represent a sagittal image plane and a meridional image plane. .

Numerical embodiment 1
Unit: mm
[Plane data]
Face number rd nd vd
1 357.6638 3.0000 1.80611 40.73
2 145.8989 0.1000
3 145.8989 10.7551 1.49700 81.61
4-794.0595 0.1500
5 135.5390 10.1849 1.43700 95.10
6 7136.8093 (d6)
7 137.9806 3.0791 1.72916 54.67
8 758.9464 20.2528
9 299.5544 2.6811 1.56732 42.84
10 -133.6568 1.0000 1.77250 49.62
11 92.0241 6.0917
12 -162.5813 0.8000 1.69680 55.46
13 83.9180 3.0070
14 -56.0081 0.8000 1.69680 55.46
15 74.4381 2.9326 1.80518 25.46
16-271.5499 (d16)
17 297.4981 3.8735 1.69680 55.46
18 -72.3818 0.1500
19 63.0217 5.0039 1.49700 81.61
20-56.2842 1.0000 1.90043 37.37
21 325.1721 0.1500
22 33.0876 4.2056 1.62004 36.30
23 102.9453 2.4546
24 46.7524 1.0000 1.91082 35.25
25 28.9828 5.7612
26 (aperture) ∞ (d26)
27 150.4164 4.1498 1.5891 31 .25
28-35.3902 1.0000 1.95375 32.32
29 -66.3121 0.1500
30 60.0137 2.5699 1.5891 61.25
31 439.8894 (d31)
32 78.1384 1.0000 1.90043 37.37
33 30.9430 8.3296
34-75.9406 1.0000 1.49700 81.61
35 32.0303 4.0594 1.64769 33.84
36 -260.4427 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.75
Wide-angle Mid-telephoto
Focal length 154.54 270.00 578.90
F number 5.20 5.81 6.51
Total angle of view 2 ω 15.63 8.97 4.19
Image height Y 21.63 21.63 21.63
Lens total length 298.6040 342.3965 377.7921

[Variable interval data]
Wide-angle Mid-telephoto
d6 47.8371 91.6295 127.0254
d16 32.3023 26.1575 3.5000
d26 30.1327 15.9882 22.9567
d31 14.6883 8.4186 1.9977
BF 62.9518 89.5109 111.6205

[Lens group data]
Group start focal length
G1 1 255.26
G2 7-46.06
G3 17 72.20
G4 27 60.80
G5 32 -60.88
G2a 7 -357.47
G2b 12 -48.13

Numerical embodiment 2
Unit: mm
[Plane data]
Face number rd nd vd
1 528.6730 3.0000 1.83481 42.72
2 143.5131 10.5261 1.49700 81.61
3-536.1702 0.1500
4 133.2008 9.3074 1.49700 81.61
5 ((d5)
6 148.9229 2.9114 1.71736 29.50
7 700.0000 22.6935
8 165.3603 2.7965 1.51742 52.15
9 -165.3603 1.0000 1.88300 40.80
10 93.6370 6.0627
11-250.0754 0.7000 1.69680 55.46
12 92.3831 2.8270
13 -57.3765 0.7000 1.69680 55.46
14 75.3753 2.7812 1.80518 25.46
15-472.9495 (d15)
16 284.2091 3.3355 1.69680 55.46
17 -67.7648 0.1500
18 70.9155 5.094 1.49700 81.61
19-53.8213 1.0000 1.90043 37.37
20 337.6022 0.1500
21 34.4130 5.7994 1.58184 40.89
22 96.3145 1.3784
23 45.9295 1.9000 1.88100 40.14
24 30.4137 5.5139
25 (F-stop) ∞ (d 25)
26 160.1209 4.1084 1.65844 50.85
27-35.9129 1.0000 1.95375 32.32
28 -80.1123 0.1500
29 67. 7459 2.2114 1.5891 61.25
30 554.6238 (d30)
31 63.9746 1.0000 1.91082 35.25
32 29.1749 8.7771
33 -72.7482 1.0000 1.43700 95.10
34 31.9872 4.5267 1.64769 33.84
35-1000.0000 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.74
Wide-angle Mid-telephoto
Focal length 154.67 270.00 578.86
F number 5.15 5.77 6.50
Total angle of view 2 ω 15.58 8.96 4.19
Image height Y 21.63 21.63 21.63
Lens total length 298.9062 343.6742 379.0453

[Variable interval data]
Wide-angle Mid-telephoto
d5 48.3963 93.1642 128.5354
d15 30.4954 25.6247 3.5000
d25 34.1791 19.6736 24.9615
d30 18.4411 9.9704 1.9974
BF 54.8430 82.6900 107.4997

[Lens group data]
Group start focal length
G1 1 256.25
G2 6 -46.11
G3 16 71.10
G4 26 65.07
G5 31 -65.77
G2a 6 -267.24
G2b 11 -51.20

Example 3
Unit: mm
[Plane data]
Face number rd nd vd
1 373.7120 3.0000 1.80611 40.73
2 148.6143 0.1000
3 148.6143 10.6839 1.49700 81.61
4-731.3819 0.1500
5 137.0582 10.1463 1.43700 95.10
6 14951.7522 (d6)
7 116.0743 4.0892 1.72916 54.67
8 403.7009 20.7778
9 293.4642 3.6165 1.56732 42.84
10 -123.6305 1.6647 1.77250 49.62
11 71.3448 6.3805
12 -145.4433 0.8000 1.69680 55.46
13 104.6635 2.6947
14 -60.2911 0.8000 1.69680 55.46
15 72.6162 2.9409 1.80518 25.46
16 -297.3883 (d16)
17 312.8853 3.8974 1.69680 55.46
18-71. 2933 0.1500
19 62.7609 5.0466 1.49700 81.61
20-56.5939 1.0000 1.90043 37.37
21 324.7258 0.1500
22 33.4685 4.1701 1.62004 36.30
23 101.2724 2.7853
24 46.3806 1.0000 1.91082 35.25
25 29. 1987 5.7625
26 (aperture) ∞ (d26)
27 141.0544 4.1662 1.58913 61.25
28 -36.0830 1.0000 1.95375 32.32
29 -68.3457 0.1500
30 59.9188 2.5555 1.5891 61.25
31 391.7408 (d31)
32 75.5933 1.0000 1.90043 37.37
33 30.9362 9.3376
34 -80.2760 1.0000 1.49700 81.61
35 31.7778 4.0939 1.64769 33.84
36 -337.4440 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.74
Wide-angle Mid-telephoto
Focal length 154.65 269.99 578.93
F number 5.18 5.80 6.48
Total angle of view 2 ω 15.66 8.98 4.19
Image height Y 21.63 21.63 21.63
Lens total length 298.6675 342.4427 378.4134

[Variable interval data]
Wide-angle Mid-telephoto
d6 43.8852 87.6604 123.6307
d16 32. 2743 25.7705 3. 5000
d26 30.3672 16.5059 23.1094
d31 14.2104 8.2370 1.9975
BF 62.8208 89.1593 111.0662

[Lens group data]
Group start focal length
G1 1 255.76
G2 7 -45.76
G3 17 71.22
G4 27 61.27
G5 32-61.45
G2a 7 -213.69
G2b 12-52.85

Example 4
Unit: mm
[Plane data]
Face number rd nd vd
1 378.1538 3.0000 1.83481 42.72
2 129.8799 10.1967 1.49700 81.61
3-1207.9001 0.1500
4 128.8993 9.5152 1.49700 81.61
5 ((d5)
6 136.4357 2.9694 1.71736 29.50
7 520.1053 22.5262
8 157.9367 2.8856 1.51742 52.15
9-157.9367 1.0000 1.88300 40.80
10 96.4016 6.0478
11-343.4654 0.7000 1.69680 55.46
12 84.3415 2.7699
13 -64.5497 0.7000 1.69680 55.46
14 63.5386 2.7771 1.80518 25.46
15 2214.2403 (d15)
16 320.9977 3.3148 1.69680 55.46
17 -66.4937 0.1500
18 72.1850 5.0395 1.49700 81.61
19-54.1974 1.0000 1.90043 37.37
20 347.1276 0.1500
21 34.9884 5.4911 1.58184 40.89
22 100.1616 0.9803
23 46.2672 1.9000 1.88100 40.14
24 30.8087 5.5414
25 (F-stop) ∞ (d 25)
26 184.7128 4.1778 1.65844 50.85
27 -36.1480 1.0000 1.95375 32.32
28 -77.2303 0.1500
29 71.5466 2.3326 1.5891 31.25
30 1830.4119 (d30)
31 77.3392 1.0000 1.91082 35.25
32 32.1806 10.2760
33 -78.1132 1.6681 1.43700 95.10
34 36.1981 4.4142 1.67270 32.17
35 10228.2235 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.74
Wide-angle Mid-telephoto
Focal length 154.65 269.95 578.87
F number 5.07 5.83 6.50
Total angle of view 2 ω 15.71 9.03 4.21
Image height Y 21.63 21.63 21.63
Lens total length 298.9917 341.5260 379.1790

[Variable interval data]
Wide-angle Mid-telephoto
d5 47.3884 89.9225 127.5760
d15 29.5144 24.3542 3.5000
d25 36.9826 19.2524 19.9625
d30 19.1013 10.5429 1.9972
BF 52.1813 83.6303 112.3196

[Lens group data]
Group start focal length
G1 1 257.80
G2 6 -46.22
G3 16 71.96
G4 26 64.13
G5 31 -65.81
G2a 6-299.30
G2b 11-49.93

Example 5
Unit: mm
[Plane data]
Face number rd nd vd
1 3732. 2439 3.0000 1.83481 42.72
2 128.8795 10.2630 1.49700 81.61
3-1288.9145 0.1500
4 128.2438 9.6096 1.49700 81.61
5 ((d5)
6 137.6764 2.9639 1.71736 29.50
7 544.3756 22.6620
8 149.6888 2.9567 1.51742 52.15
9-149.6888 1.0000 1.88300 40.80
10 94.6010 6.0666
11-314.7976 0.7000 1.69680 55.46
12 86.0375 2.7411
13 -64.5500 0.7000 1.69680 55.46
14 64.5618 2.7794 1.80518 25.46
15 5702.1522 (d15)
16 346.2888 3.2611 1.69680 55.46
17 -67.4490 0.1500
18 75.1045 4.9850 1.49700 81.61
19-54.3536 1.0000 1.90043 37.37
20 388.8141 0.1500
21 35.6793 4.7690 1.58144 40.89
22 107.1754 1.0796
23 47.2787 1.9000 1.88100 40.14
24 31.5149 5.5389
25 (F-stop) ∞ (d 25)
26 198.8545 4.1456 1.65844 50.85
27 -36.1922 1.0000 1.95375 32.32
28 -75.7005 0.1500
29 69.5985 2.3143 1.59349 67.00
30 1112.9 818 (d30)
31 75.6091 1.0000 1.90043 37.37
32 32.3743 11.1880
33 -83.0905 1.0000 1.43700 95.10
34 36.5367 4.2928 1.67270 32.17
35 674.4266 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.74
Wide-angle Mid-telephoto
Focal length 154.65 269.99 578.88
F number 5.04 5.86 6.49
Total angle of view 2 ω 15.71 9.03 4.21
Image height Y 21.63 21.63 21.63
Lens total length 299.0765 340.6390 379.3817

[Variable interval data]
Wide-angle Mid-telephoto
d5 46.8751 88.4376 127.1801
d15 28.9404 23.7846 3.5000
d25 38.1845 19.9778 21.7946
d30 19.5085 10.9735 1.9975
BF 52.0514 83.9489 111.3929

[Lens group data]
Group start focal length
G1 1 257.64
G2 6 -46.46
G3 16 73.66
G4 26 63.71
G5 31 -64.70
G2a 6 -292.50
G2b 11-50.41

Example 6
Unit: mm
[Plane data]
Face number rd nd vd
1 365.491 3.0000 1.83481 42.72
2 127.0846 10.3041 1.49700 81.61
3-1427.5505 0.1500
4 127.1046 9.6873 1.49700 81.61
5 ((d5)
6 144.9780 3.0032 1.71736 29.50
7 709.8099 22.5926
8 139.7435 3.0691 1.51742 52.15
9-139.7435 1.0000 1.88300 40.80
10 91.2159 6.1098
11-305.2. 2438 0.7000 1. 69680 55. 46
12 87.7611 2.7308
13 -64.5798 0.7000 1.69680 55.46
14 66.8529 2.7379 1.80518 25.46
15 6415.1292 (d15)
16 917.0159 3.1606 1.62041 60.34
17 -65.4856 0.1500
18 81.4594 5.1676 1.49700 81.61
19-50.2651 1.0000 1.91082 35.25
20 12857.9429 0.1500
21 39.7020 3.7454 1.64769 33.84
22 165.3683 3.3038
23 52.9808 1.9000 1.88100 40.14
24 33.0522 5.4858
25 (F-stop) ∞ (d 25)
26 294.0289 4.2603 1.69680 55.46
27 -35.1097 1.0000 1.95375 32.32
28 -80.1614 0.1500
29 78.1387 2.5322 1.59349 67.00
30 -377.4708 (d30)
31 87.7761 1.0000 1.80420 46.50
32 26.8830 2.2144 1.72825 28.32
33 36.6224 21.2579
34 -101.5049 2.0000 1.43700 95.10
35 37.2848 4.1070 1.60342 38.01
36 203.2256 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.74
Wide-angle Mid-telephoto
Focal length 154.77 270.00 578.86
F number 5.06 5.84 6.49
Total angle of view 2 ω 15.71 9.03 4.21
Image height Y 21.63 21.63 21.63
Lens total length 298.7481 340.7869 379.0428

[Variable interval data]
Wide-angle Mid-telephoto
d5 46.0134 88.0521 126.3078
d15 29.1520 23.7340 3.5000
d25 32.6154 19.6895 25.1890
d30 17.4253 10.1944 1.9975
BF 45.1711 70.7460 93.6776

[Lens group data]
Group start focal length
G1 1 257.14
G2 6-46.18
G3 16 77.20
G4 26 62.34
G5 31 -59.18
G2a 6 -277.76
G2b 11-50.55
G5a 31 -75.35
G5b 34 -357.07

Example 7
Unit: mm
[Plane data]
Face number rd nd vd
1 370.6330 3.0000 1.83481 42.72
2 127.6111 10.3116 1.49700 81.61
3 -1345.5535 0.1500
4 127.2682 9.6767 1.49700 81.61
5 ((d5)
6 145.7558 2.9973 1.71736 29.50
7 723.8084 22.5896
8 140.5816 3.0595 1.51742 52.15
9-140.5816 1.0000 1.88300 40.80
10 91.5361 6.1057
11-300.0543 0.7000 1.69680 55.46
12 88.4743 2.7214
13 -64.5061 0.7000 1.69680 55.46
14 66.6869 2.7410 1.80518 25.46
15 6186.2394 (d15)
16 1220.3717 3.1551 1.6204 1 60.34
17 -64.6325 0.1500
18 82.7645 5.1690 1.49700 81.61
19-49.8333 1.0000 1.91082 35.25
20-4479.2347 0.1500
21 39.6642 3.7281 1.64769 33.84
22 159.7630 3.4204
23 52.6520 1.9000 1.88100 40.14
24 32.9896 5.4905
25 (F-stop) ∞ (d 25)
26 285.4516 4.2383 1.69680 55.46
27-35.2509 1.0000 1.95375 32.32
28 -81.6685 0.1500
29 80.1273 2.5468 1.59349 67.00
30 -304.8572 (d30)
31 88.3160 1.0000 1.80420 46.50
32 27.2454 2.1595 1.75520 27.53
33 36.0764 (d33)
34 -96.6261 1.9935 1.43700 95.10
35 38.1247 4.1376 1.60342 38.01
36 223.3526 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.74
Wide-angle Mid-telephoto
Focal length 154.77 269.96 578.86
F number 5.10 5.84 6.51
Total angle of view 2 ω 15.71 9.03 4.21
Image height Y 21.63 21.63 21.63
Lens total length 298.8477 341.1342 379.1761

[Variable interval data]
Wide-angle Mid-telephoto
d5 46.2834 88.5697 126.6121
d15 29.7073 23.7653 3.5000
d25 31.4942 20.0095 25.3557
d30 16.6915 10.2099 1.9971
d33 22.6552 20.3464 21.2514
BF 44.8745 71.0918 93.3182

[Lens group data]
Group start focal length
G1 1 257.40
G2 6 -46.22
G3 16 77.13
G4 26 62.12
G5 31 -75.06
G6 33-350.93
G2a 6 -278.80
G2b 11-50.58

Example 8
Unit: mm
[Plane data]
Face number rd nd vd
1 550.2301 3.0000 1.83481 42.72
2 144.9435 10.6178 1.49700 81.61
3-508.0778 0.1500
4 133.4833 9.2990 1.49700 81.61
5 ((d5)
6 148.9001 2.9142 1.71736 29.50
7 700.0000 22.4340
8 159.6819 2.8639 1.51742 52.15
9-159.6819 1.0000 1.88300 40.80
10 91. 2597 6.1064
11-214.1812 0.7000 1.69680 55.46
12 94.8167 2.8442
13 -57.6477 0.7000 1.69680 55.46
14 76.1754 2.8444 1.80518 25.46
15 -392.6584 (d15)
16 235.0685 3.5316 1.69680 55.46
17 -66.2550 0.1500
18 70.0938 5.2152 1.49700 81.61
19-53.3381 1.0000 1.90043 37.37
20 296.4532 0.1500
21 34.3415 5.7678 1.58184 40.89
22 89.1967 2.6246
23 46.2929 1.9000 1.88100 40.14
24 30.4491 5.4557
25 (F-stop) ∞ (d 25)
26 154.5168 4.0267 1.65844 50.85
27 -36.8251 1.0000 1.95375 32.32
28-82. 3995 0.1500
29 63.3772 2.2199 1.5891 31.25
30 373.4005 (d30)
31 64.6555 1.0000 1.91082 35.25
32 29.1373 8.8009
33-73.8858 1.0000 1.43700 95.10
34 31.7813 4.5840 1.64769 33.84
35-1000.0000 (BF)
Image plane ∞

[Various data]
Zoom ratio 3.74
Wide-angle Mid-telephoto
Focal length 154.67 270.01 578.85
F number 5.14 5.75 6.50
Total angle of view 2 ω 15.58 8.95 4.19
Image height Y 21.63 21.63 21.63
Lens total length 298.9154 344.1588 379.0824

[Variable interval data]
Wide-angle Mid-telephoto
d5 47.8096 93.0528 127.9769
d15 30.3675 25.8998 3.5000
d25 34.5016 19.2696 25.0138
d30 18.0578 9.2937 1.9973
BF 54.1286 82.5926 106.5441

[Lens group data]
Group start focal length
G1 1 255.82
G2 6-45.90
G3 16 69.85
G4 26 64.59
G5 31 -65.63
G2a 6 -254.33
G2b 11-51.56

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 8
Conditional Expression 1 0.814 0.781 0.732 0.790 0.785 0.778 0.779 0.776
Conditional Expression 2-0.0144-0.0153-0.0190-0.0161-0.0166-0.0170-0.0169-0.0150

Further, in the image forming optical system of the present invention, it is more effective to accompany the following configuration.

It is more desirable that the rear lens unit comprises, in order from the object side, a third lens unit of positive refractive power, a fourth lens unit of positive refractive power, and a fifth lens unit of negative refractive power.

However, the present invention does not exclude configurations other than the above-described five-group configuration. As a matter of course, further behind the fifth lens group, there is also included a configuration in which a single-piece reduced-magnification optical system with various aberrations sufficiently corrected or a multiplication optical system is added. Of course, the system in which the reduction optical system or the multiplication optical system is added to the optical system of the present invention having the first to fifth lens groups has the first to fifth lens groups. Is a system having the features of the optical system of The optical system is not essentially changed before and after addition of the demagnification optical system or the multiplication optical system.

More desirably, the 2a group includes a positive lens and a cemented lens including a positive lens and a negative lens in this order from the object side.

It is more desirable that the 2b group be composed of three or less lenses including one positive lens. When the number of sheets is four or more, it is difficult to suppress the weight of the vibration reduction group.

Further, in order to correct the chromatic aberration of the 2b group to suppress the generation of the lateral chromatic aberration at the time of image stabilization, it is desirable to have at least one positive lens in the 2b group.

Further, it is desirable to have two negative lenses in the 2b group in order to suppress the occurrence of spherical aberration, coma aberration, etc. while maintaining the negative refracting power of the 2b group sufficiently.

G1 First lens group G2 Second lens group G2a 2a group (second lens group front group)
G2b 2b group (second lens group rear group)
Gr Rear lens group G3 third lens group G4 fourth lens group G5 fifth lens group G5a 5a group (fifth lens group front group)
G5b 5b group (5th lens group rear group)
G6 sixth lens group S aperture stop I image plane

Claims (4)

From the object side,
A first lens group of positive refractive power,
A second lens unit of negative refractive power,
It consists of a rear lens group of positive refractive power as a whole throughout the magnification variation,
The rear lens unit is arranged in order from the object side
The third lens group having a positive refractive power, the fourth lens group having a positive refractive power, and the fifth lens group having a negative refractive power
Or a third lens group of positive refractive power, a fourth lens group of positive refractive power, a fifth lens group of negative refractive power, and a sixth lens group of negative refractive power,
The lens groups are separated by an air gap, and the air gap between the lens groups changes during zooming.
The rear lens group consists of at least two lens groups that move in independent trajectories during zooming,
The second lens group is composed of, in order from the object side, a 2a group of negative refractive power and a 2b group of negative refractive power, and performs image stabilization by displacing the 2b group in a direction orthogonal to the optical axis,
The group 2a has a lens component with positive refractive power on the object side,
A variable magnification imaging optical system having a vibration reduction function characterized by satisfying the following conditional expression.
(1) 0.70 <| LT2a / f2a | <0.85
(2)-0.025 <dpp2a / | f2a | <-0.005
However,
LT2a is the distance from the most object side surface of the 2a group to the image side focal point of the 2a group,
f2a is the focal length of the 2a group,
dpp2a is the distance from the object-side principal point of the 2a group to the image-side principal point,
It is.   The variable magnification imaging optical system having an anti-vibration function according to claim 1, wherein the second lens group is fixed to an image plane at the time of zooming. The variable magnification imaging optical system having a vibration reduction function according to claim 1 or 2, wherein the rear lens group is provided with a third lens group of positive refractive power on the object side most.   The rear lens group has a lens group of negative refractive power closest to the image side, and moves all or part of any lens group excluding the third lens group in the rear lens group during focusing. A variable magnification imaging optical system having a vibration isolation function according to claim 3, characterized in that

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