JP5562552B2 - Inner focus type anti-vibration lens - Google Patents

Description

The present invention relates to a zoom lens used for a digital camera, a silver salt camera, a video camera, and the like.

The following documents are known as zoom lenses having an anti-vibration function and a zoom ratio of about 4 times.
JP 2006-337648 A JP 2007-206542 A JP 2008-122775 A

The zoom lens in Patent Document 1 is a zoom lens having a five-group configuration, but the movement of each lens group on the optical axis during zooming is to fix the second lens group and the fourth lens group, which are anti-vibration groups. This simplifies the mechanical structure. However, since the entire length of the wide-angle end is longer than the focal length at the wide-angle end, the entire lens system is large. In addition, there is a problem that the operability at the time of focusing is impaired due to the focus system feeding out the front lens.

In the zoom lens in Patent Document 2, the focus method is an inner focus, and the entire length is short and the lens diameter is reduced. In addition, there are three operating groups during zooming, which is a simple configuration. However, since the third lens group is divided into three auxiliary lens groups, and the second auxiliary lens group is used as an anti-vibration group, the third lens group is divided into three and the zoom operation group is three groups. Nevertheless, the number of components has increased, which has been a factor in increasing costs. Further, since the center divided into three operates as a vibration isolation group, the optical axis alignment of the front and rear groups of the vibration isolation group becomes a burden on the mechanical structure.

The zoom lens in Patent Document 3 is a four-group zoom lens, and the second lens group, which is an anti-vibration group, is fixed during zooming, so there are few parts and the mechanical structure is simplified. However, since the entire length of the wide-angle end is longer than the focal length of the wide-angle end as in Patent Document 1, the entire lens system is large. Further, there is a problem that the operability at the time of focusing is impaired due to the focus system feeding out the front lens.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inner focus type vibration-proof lens having a small number of component parts, low cost, and good optical performance.

In order to solve the above-described problems, the present invention provides an optical system in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens having a positive refractive power. a lens group, is composed of a fourth lens group having positive refractive power, by changing the distances between the lens groups have rows zooming, the first lens group on the object side with the zooming telephoto end from the wide-angle end a inner focus type of anti-vibration lens which moves the first lens group includes a first 1a lens group which is fixed not to move during focusing, infinity object side on the optical axis upon focusing on a close object The second lens group is moved in a substantially vertical direction with respect to the optical axis to move the image in a substantially vertical direction with respect to the optical axis. Satisfying the following conditions: It is characterized in.
0.30 <| f2 / fw | <0.45 (1)
Where f2 is the focal length of the second lens group, and fw is the focal length of the entire system at the wide angle end.

  According to the present invention, it is possible to achieve an inner focus type anti-vibration lens with few constituent parts, low cost, and good optical performance.

In the anti-vibration lens according to the present invention, the optical system is arranged in order from the object side, the first lens group Gr1 having positive refractive power, the second lens group Gr2 having negative refractive power, and the third lens group having positive refractive power. and Gr3, is composed of a fourth lens unit Gr4 having a positive refractive power, by changing the distances between the lens groups have rows zooming, the first lens group on the object side with the zooming telephoto end from the wide-angle end Move to .

The first lens group Gr1 includes a first-a lens group Gr1a and a first-b lens group Gr1b from the object side. The first-a lens group Gr1a is fixed without moving during focusing, and the first-b lens group Gr1b is moved to the object side on the optical axis when focusing from infinity to a short-distance object.

By moving the second lens group Gr2 in a direction substantially perpendicular to the optical axis, it becomes possible to move the image in a direction substantially perpendicular to the optical axis, and image blurring on the image plane when camera shake occurs. Make corrections.

  The amount of zooming from the wide-angle end of the second lens group Gr2 to the telephoto side is made small, and the overall mechanical structure is simplified.

  In order to reduce the size of the second lens group Gr2, which is an anti-vibration lens group, first, the refractive power of the first lens group Gr1 was increased, and the height of light rays reaching the second lens group Gr2 was decreased. Then, the refractive power of the second lens group Gr2, which is also a variable power lens group, is made relatively large, the movement amount between the lens groups is reduced, the overall length during zooming is shortened, and the mechanical structure is simplified.

In order to gently refract the light beam bounced up by the second lens group Gr2, at least one positive lens after the stop of the third lens group Gr3 is refracted, and the incident angle of the light beam toward the cemented lens thereafter Is reduced to reduce spherical aberration.

  The configuration of the fourth lens group Gr4 is a lens configuration having positive and negative refractive powers. The first lens is a lens having a positive refractive power, and the height of light rays in the subsequent lenses is lowered by refracting off-axis rays toward the optical axis. In addition, by placing a flare cut near the lens with this positive refractive power, it is possible to cut the light flare component above the intermediate angle of view without cutting the light reaching the maximum angle of view, ensuring a sufficient amount of peripheral light. In addition, the performance of the intermediate angle of view can be improved. In addition, the arrangement of the second lens with positive refractive power and the lens with negative refractive power corrects the tangential astigmatism generated so far, and the negative refractive power behind it. The distortion remaining by the lens is corrected in the positive direction.

The fourth lens group Gr4 has a negative refracting power lens that is a cemented lens of a negative refracting power lens and a positive refracting power lens. The radius of curvature of the concave surface can be increased, thereby reducing coma aberration and spherical aberration at the telephoto end, and reducing excessive distortion in the positive direction caused by downsizing. .

By making the final surface of the fourth lens group Gr4 convex toward the image surface side, the light reflected by the image surface is prevented from being reflected by the final lens surface and heading again to the image surface.

It is desirable to satisfy the following formula (1), where f2 is the focal length of the second lens group Gr2, and fw is the focal length of the entire system at the wide-angle end.
0.30 <| f2 / fw | <0.45 (1)

Conditional expression (1) defines the refractive power for the second lens group Gr2 to function as an anti-vibration lens group. When the lower limit of (1) is exceeded, the refractive power of the second lens group Gr2 increases, and the lateral magnification of the image stabilizing lens group increases. As a result, the amount of movement of the second lens group Gr2 for correcting blur is reduced, and the range of the drive error is narrowed, making it difficult to control the image stabilizing lens group. In addition, it becomes difficult to correct aberrations such as coma during image stabilization. Further, when the upper limit of (1) is exceeded, the refractive power of the second lens group Gr2 becomes small, and the movement amount of the second lens group Gr2 for correcting the shake increases, whereby the radial direction mechanism of the vibration-proof lens group. The configuration becomes large.

It is desirable to satisfy the following formula (2), where f1 is the focal length of the first lens group Gr1, and R2 is the radius of curvature of the most object-side surface of the second lens group Gr2.
-1.20 <f1 / R2 <-0.30 (2)

Conditional expression (2) defines an appropriate ratio between the focal length of the first lens group Gr1 and the radius of curvature of the most object-side surface of the second lens group Gr2. When the lower limit of (2) is exceeded, the ratio of the radius of curvature of the surface closest to the object side of the second lens group Gr2 becomes small, so that coma aberration is increased and correction of aberrations becomes difficult particularly at the wide-angle end. Further, the occurrence of tangential astigmatism when the second lens group Gr2 is moved perpendicularly to the optical axis is increased. When the upper limit of (2) is exceeded, the refractive power of the first lens group Gr1 becomes strong, and it becomes difficult to correct spherical aberration and coma aberration in the subsequent lens groups.

It is desirable to satisfy the following formula (3), where f1 is the focal length of the first lens group Gr1, and f2 is the focal length of the second lens group Gr2.
3.00 <| f1 / f2 | <4.50 (3)

Conditional expression (3) defines an appropriate range of the focal length of the first lens group Gr1 and the focal length of the second lens group Gr2. If the lower limit of (3) is exceeded, the refractive power of the second lens group Gr2 becomes small, the amount of movement of each lens group for zooming to the focal length at the telephoto end becomes large, and it becomes difficult to downsize the entire system. If the upper limit of (3) is exceeded, the refractive power of the second lens group Gr2 becomes strong, and correction of aberrations such as coma becomes difficult in the entire system.

It is desirable that the following expression (4) is satisfied, where ν1b is the Abbe number of the positive lens in the d-line in the first lens group Gr1b.
ν1b> 70.00 (4)

In order to reduce the aberration of the entire system, particularly chromatic aberration, the Abbe number of the positive refractive power lens in the 1b lens group Gr1b needs to be larger than the lower limit of (4). Further, in order to reduce aberration when the first-b lens group Gr1b, which is the focus group, moves to the short distance side, it is desirable to use a low dispersion glass with ν1b of 80.00 or more.

Example 1
FIG. 1 is a lens configuration diagram of an inner focus type vibration-proof lens according to Example 1 of the present invention.

In FIG. 1, the inner focus type vibration-proof lens includes, in order from the object side, a first lens group Gr1 having a positive refractive power, a second lens group Gr2 having a negative refractive power, and a third lens having a positive refractive power. a lens group Gr3, is composed of a fourth lens unit Gr4 having a positive refractive power, by changing the distances between the lens groups have rows zooming, the first lens group along with the zooming telephoto end from the wide-angle end It is the structure which moves to the object side .

The first lens group Gr1 includes a fixed 1a lens group Gr1a that does not move during focusing, and a 1b lens group that performs focusing by moving the optical axis toward the object side when focusing from infinity to a short distance object. Gr1b. The first-a lens group Gr1a includes a biconvex lens group having a positive refractive power, and the first-b lens group Gr1b includes a meniscus lens having a negative refractive power with a convex surface facing the object direction and a biconvex positive lens element. It is composed of a cemented lens with a lens having refractive power.

The second lens group Gr2 moves in the direction substantially perpendicular to the optical axis, thereby moving the image on the image plane I in the direction perpendicular to the optical axis to enable image blur correction. The second lens group Gr2 includes a cemented lens composed of a biconcave lens having negative refractive power and a meniscus lens having positive refractive power with the convex surface facing the object, and a biconcave negative lens. It is comprised from the lens which has the refractive power of.

The third lens group Gr3 includes a biconvex lens having a positive refractive power, a meniscus lens having a positive refractive power with a convex surface facing the object direction, a biconvex lens having a positive refractive power and a biconcave lens. And a cemented lens with a lens having negative refractive power.

The fourth lens group Gr4 includes a biconvex lens having a positive refractive power, a meniscus lens having a positive refractive power with a convex surface facing the object direction, a biconcave lens having a negative refractive power and a biconvex lens. And a cemented lens with a lens having a positive refractive power.

The aperture stop is disposed on the object side of the third lens group Gr3, and moves together with the third lens group Gr3 during zooming.

When camera shake occurs, the anti-vibration lens group has only to be moved by (f · tan θ) / K, where image blur is rotational blur of angle θ, the focal length of the entire system is f, and the anti-shake coefficient is K. . The image stabilization coefficient is the ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction.

In the wide-angle end state in the first embodiment, the image stabilization coefficient K is 1.87, and the focal length f is 51.59. When the second lens group Gr2 is moved by 3.00 mm, a rotational blur of 0.62 ° can be corrected. In the telephoto end state, the image stabilization coefficient K is 4.44 and the focal length f is 194.18. When the second lens group Gr2 is moved by 3.00 mm, rotational blur of 0.39 ° can be corrected.

Table 1 below lists values of specifications of the inner focus type vibration-proof lens according to the first example.
In [Overall Specifications], f represents a focal length, Fno represents an F number, and 2ω represents an angle of view (unit: °). In [Lens Specifications], the first column number is the lens surface number from the object side, the second column r is the radius of curvature of the lens surface, the third column d is the lens surface interval, and the fourth column n is d line ( The refractive index for the wavelength λ = 587.56 mm), the fifth column ν is the Abbe number for the d-line. “Aperture” in the second row represents the stop surface, and FB in the third row represents the back focus. [Variable interval at zooming at infinity] indicates the focal length f and the value of the variable interval. [Variable interval at the time of focusing] indicates a value of a focusing movement amount with reference to a feeding amount at a shooting distance of 1100 mm at the telephoto end. [Condition value] represents the value of each conditional expression. These symbols are the same in the other embodiments below, and the description thereof is omitted.

  In all the following values of specifications, “mm” is used as the focal length f, radius of curvature r, lens surface interval d, and other length units unless otherwise specified. However, since the same optical performance can be obtained in proportional enlargement and proportional reduction, it is not limited to this. Fno is the F number, 2ω is the angle of view, n is the refractive index of the d-line, ν is the Abbe number of the d-line, the aperture is the stop surface, and FB is the back focus. These symbols are the same in the other embodiments below, and the description thereof is omitted.

(Example 2)
FIG. 7 is a lens configuration diagram of an inner focus type anti-vibration lens according to Example 2 of the present invention.

In FIG. 7, the inner focus type anti-vibration lens includes, in order from the object side, a first lens group Gr1 having a positive refractive power, a second lens group Gr2 having a negative refractive power, and a third lens having a positive refractive power. a lens group Gr3, is composed of a fourth lens unit Gr4 having a positive refractive power, by changing the distances between the lens groups have rows zooming, the first lens group along with the zooming telephoto end from the wide-angle end It is the structure which moves to the object side .

The first lens group Gr1 includes a fixed 1a lens group Gr1a that does not move during focusing, and a 1b lens group that performs focusing by moving the optical axis toward the object side when focusing from infinity to a short distance object. Gr1b. The first-a lens group Gr1a includes a biconvex lens group having a positive refractive power, and the first-b lens group Gr1b includes a meniscus lens having a negative refractive power with a convex surface facing the object direction and a biconvex positive lens element. It is composed of a cemented lens with a lens having refractive power.

The second lens group Gr2 moves in the direction substantially perpendicular to the optical axis, thereby moving the image on the image plane I in the direction perpendicular to the optical axis to enable image blur correction. The second lens group Gr2 includes, in order from the object side, a cemented lens of a biconcave lens having negative refractive power and a meniscus lens having positive refractive power with the convex surface facing the object, and a concave surface on the object side. And a meniscus lens having negative refractive power with a convex surface facing the image surface I side.

The third lens group Gr3 includes a biconvex lens having a positive refractive power, a meniscus lens having a positive refractive power with a convex surface facing the object direction, a biconvex lens having a positive refractive power and a biconcave lens. And a cemented lens with a lens having negative refractive power.

The fourth lens group Gr4 includes a biconvex lens having a positive refractive power, a meniscus lens having a positive refractive power with a convex surface facing the object direction, a biconcave lens having a negative refractive power and a biconvex lens. And a cemented lens with a lens having a positive refractive power.

The aperture stop is disposed on the object side of the third lens group Gr3, and moves together with the third lens group Gr3 during zooming.

When camera shake occurs, the anti-vibration lens group has only to be moved by (f · tan θ) / K, where image blur is rotational blur of angle θ, the focal length of the entire system is f, and the anti-shake coefficient is K. . The image stabilization coefficient is the ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction.

In the wide-angle end state in the second embodiment, the image stabilization coefficient K is 1.89, and the focal length f is 51.78. When the second lens group Gr2 is moved by 3.00 mm, a rotational blur of 0.63 ° can be corrected. In the telephoto end state, the image stabilization coefficient K is 4.47, and the focal length f is 193. 33 . When the second lens group Gr2 is moved by 3.00 mm, a rotational blur of 0.40 ° can be corrected.

  Table 2 below lists values of specifications of the inner focus type vibration-proof lens according to the second example.

(Example 3)
FIG. 13 is a lens configuration diagram of an inner focus type vibration-proof lens according to Example 3 of the present invention.

In FIG. 13, the inner focus type anti-vibration lens includes, in order from the object side, a first lens group Gr1 having a positive refractive power, a second lens group Gr2 having a negative refractive power, and a third lens having a positive refractive power. a lens group Gr3, is composed of a fourth lens unit Gr4 having a positive refractive power, by changing the distances between the lens groups have rows zooming, the first lens group along with the zooming telephoto end from the wide-angle end It is the structure which moves to the object side .

The first lens group Gr1 includes a fixed 1a lens group Gr1a that does not move during focusing, and a 1b lens group that performs focusing by moving the optical axis toward the object side when focusing from infinity to a short distance object. Gr1b. The first-a lens group Gr1a includes a biconvex lens group having a positive refractive power, and the first-b lens group Gr1b includes a meniscus lens having a negative refractive power with a convex surface facing the object direction and a biconvex positive lens element. It is composed of a cemented lens with a lens having refractive power.

The second lens group Gr2 moves in the direction substantially perpendicular to the optical axis, thereby moving the image on the image plane I in the direction perpendicular to the optical axis to enable image blur correction. The second lens group Gr2 includes a cemented lens composed of a biconcave lens having negative refractive power and a meniscus lens having positive refractive power with the convex surface facing the object, and a biconcave negative lens. It is comprised from the lens which has the refractive power of.

The third lens group Gr3 includes a biconvex lens having a positive refractive power, a meniscus lens having a positive refractive power with a convex surface facing the object direction, a biconvex lens having a positive refractive power and a biconcave lens. And a cemented lens with a lens having negative refractive power.

The fourth lens group Gr4 has a meniscus lens having a positive refractive power with a concave surface facing the object direction, a meniscus lens having a positive refractive power with a convex surface facing the object direction, and a negative refractive power having a biconcave shape. It is composed of a lens and a cemented lens of a biconvex lens having positive refractive power.

The aperture stop is disposed on the object side of the third lens group Gr3, and moves together with the third lens group Gr3 during zooming.

When camera shake occurs, the anti-vibration lens group has only to be moved by (f · tan θ) / K, where image blur is rotational blur of angle θ, the focal length of the entire system is f, and the anti-shake coefficient is K. . The image stabilization coefficient is the ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction.

In the wide-angle end state in the third embodiment, the image stabilization coefficient K is 1.99, and the focal length f is 51.40. When the second lens group Gr2 is moved by 3.00 mm, a rotational blur of 0.67 ° can be corrected. In the telephoto end state, the image stabilization coefficient K is 4.84, and the focal length f is 193. 91 . When the second lens group Gr2 is moved by 3.00 mm, 0.43 ° rotational blur can be corrected.

  Table 3 below lists values of specifications of the inner focus type vibration-proof lens according to the third example.

(Example 4)
FIG. 19 is a lens configuration diagram of an inner focus type image stabilization lens according to Example 4 of the present invention.

In FIG. 19, the inner focus type anti-vibration lens includes, in order from the object side, a first lens group Gr1 having a positive refractive power, a second lens group Gr2 having a negative refractive power, and a third lens having a positive refractive power. a lens group Gr3, is composed of a fourth lens unit Gr4 having a positive refractive power, by changing the distances between the lens groups have rows zooming, the first lens group along with the zooming telephoto end from the wide-angle end It is the structure which moves to the object side .

The first lens group Gr1 includes a fixed 1a lens group Gr1a that does not move during focusing, and a 1b lens group that performs focusing by moving the optical axis toward the object side when focusing from infinity to a short distance object. Gr1b. The first-a lens group Gr1a is composed of a biconvex lens group having positive refractive power, and the first-b lens group Gr1b is a meniscus lens having negative refractive power with a convex surface facing the object direction, and a biconvex positive lens element. The lens is composed of a cemented lens with a lens having a refractive power of 2.

The second lens group Gr2 moves in the direction substantially perpendicular to the optical axis, thereby moving the image on the image plane I in the direction perpendicular to the optical axis to enable image blur correction. The second lens group Gr2 includes a cemented lens composed of a biconcave lens having negative refractive power and a meniscus lens having positive refractive power with the convex surface facing the object, and a biconcave negative lens. It is comprised from the lens which has the refractive power of.

The third lens group Gr3 includes a biconvex lens having a positive refractive power and a cemented lens of a biconvex lens having a positive refractive power and a biconcave lens having a negative refractive power. Is done.

The fourth lens group Gr4 includes a biconvex lens having a positive refractive power, a meniscus lens having a positive refractive power with a convex surface facing the object direction, a biconcave lens having a negative refractive power and a biconvex lens. It is composed of a cemented lens with a lens having a positive refractive power.

The aperture stop is disposed on the object side of the third lens group Gr3, and moves together with the third lens group Gr3 during zooming.

When camera shake occurs, the anti-vibration lens group has only to be moved by (f · tan θ) / K, where image blur is rotational blur of angle θ, the focal length of the entire system is f, and the anti-shake coefficient is K. . The image stabilization coefficient is the ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction.

In the wide-angle end state in the fourth embodiment, the image stabilization coefficient K is 1.87, and the focal length f is 51.47. When the second lens group Gr2 is moved by 3.00 mm, a rotational blur of 0.62 ° can be corrected. In the telephoto end state, the image stabilization coefficient K is 4.45, and the focal length f is 193.95 . When the second lens group Gr2 is moved by 3.00 mm, rotational blur of 0.39 ° can be corrected.

  Table 4 below lists values of specifications of the inner focus type vibration-proof lens according to the fourth example.

(Example 5)
FIG. 25 is a lens configuration diagram of an inner focus type vibration-proof lens according to Example 5 of the present invention.

In FIG. 25, the inner focus type anti-vibration lens includes, in order from the object side, a first lens group Gr1 having a positive refractive power, a second lens group Gr2 having a negative refractive power, and a third lens having a positive refractive power. a lens group Gr3, is composed of a fourth lens unit Gr4 having a positive refractive power, by changing the distances between the lens groups have rows zooming, the first lens group along with the zooming telephoto end from the wide-angle end It is the structure which moves to the object side .

The first lens group Gr1 includes a fixed 1a lens group Gr1a that does not move during focusing, and a 1b lens group that performs focusing by moving the optical axis toward the object side when focusing from infinity to a short distance object. Gr1b. The first-a lens group Gr1a includes a biconvex lens group having a positive refractive power, and the first-b lens group Gr1b includes a meniscus lens having a negative refractive power with a convex surface facing the object direction and a biconvex positive lens element. It is composed of a cemented lens with a lens having refractive power.

The second lens group Gr2 moves in the direction substantially perpendicular to the optical axis, thereby moving the image on the image plane I in the direction perpendicular to the optical axis to enable image blur correction. The second lens group Gr2 includes a cemented lens composed of a biconcave lens having negative refractive power and a meniscus lens having positive refractive power with the convex surface facing the object, and a biconcave negative lens. It is comprised from the lens which has the refractive power of.

The third lens group Gr3 includes a biconvex lens having a positive refractive power, a biconvex lens having a positive refractive power and a biconcave lens having a negative refractive power, and an object direction. And a meniscus lens having a positive refractive power with a convex surface directed .

The fourth lens group Gr4 includes a biconvex lens having a positive refractive power, a meniscus lens having a positive refractive power with a convex surface facing the object direction, a biconcave lens having a negative refractive power and a biconvex lens. And a cemented lens with a lens having a positive refractive power.

The aperture stop is disposed on the object side of the third lens group Gr3, and moves together with the third lens group Gr3 during zooming.

When camera shake occurs, the anti-vibration lens group has only to be moved by (f · tan θ) / K, where image blur is rotational blur of angle θ, the focal length of the entire system is f, and the anti-shake coefficient is K. .
The image stabilization coefficient is the ratio of the amount of image movement on the imaging surface to the amount of movement of the moving lens group in shake correction.

In the wide-angle end state in the fifth embodiment, the image stabilization coefficient K is 1.88, and the focal length f is 51.57. When the second lens group Gr2 is moved by 3.00 mm, a rotational blur of 0.63 ° can be corrected. In the telephoto end state, the vibration reduction coefficient K is 4.45, the focal length f is 193.9 2. When the second lens group Gr2 is moved by 3.00 mm, rotational blur of 0.39 ° can be corrected.

  Table 5 below provides values of specifications of the inner focus type vibration-proof lens according to Example 5.

1 is a lens configuration diagram of a zoom lens according to Example 1 of the present invention. FIG. These are various aberrations when focusing on infinity at the wide angle end (f = 51.59 mm) of the zoom lens according to Example 1 of the present invention. These are various aberrations when focusing at infinity at the intermediate focal length (f = 99.94 mm) of the zoom lens according to Example 1 of the present invention. These are various aberrations when focusing on infinity at the telephoto end (f = 194.18 mm) of the zoom lens according to Example 1 of the present invention. FIG. 9 is a lateral aberration diagram at normal time at infinite focus at the wide-angle end of the zoom lens according to Example 1 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens group is moved by +0.3 mm along the optical axis; It is a lateral aberration diagram at the time of anti-vibration in which the anti-vibration lens group is moved by -0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram at normal time at infinity focusing at the telephoto end of the zoom lens according to Example 1 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 6 is a lens configuration diagram of a zoom lens according to Example 2 of the present invention. These are various aberrations when focusing on infinity at the wide-angle end (f = 51.78 mm) of the zoom lens according to Example 2 of the present invention. These are various aberrations when focusing at infinity at the intermediate focal length (f = 99.53 mm) of the zoom lens according to Example 2 of the present invention. These are various aberrations when focusing on infinity at the telephoto end (f = 193.33 mm) of the zoom lens according to Example 2 of the present invention. FIG. 7 is a lateral aberration diagram at normal time with infinite focus at the wide angle end of the zoom lens according to Example 2 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm about the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 7 is a lateral aberration diagram at normal time at infinite focus at the telephoto end of the zoom lens according to Example 2 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 6 is a lens configuration diagram of a zoom lens according to Example 3 of the present invention. These are various aberrations when focusing on infinity at the wide angle end (f = 51.40 mm) of the zoom lens according to Example 3 of the present invention. These are various aberrations when focusing at infinity at the intermediate focal length (f = 99.90 mm) of the zoom lens according to Example 3 of the present invention. These are various aberrations when focusing on infinity at the telephoto end (f = 193.91 mm) of the zoom lens according to Example 3 of the present invention. FIG. 9 is a lateral aberration diagram at normal time at infinite focus at the wide angle end of the zoom lens according to Example 3 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 9 is a lateral aberration diagram at normal time when focusing at infinity at the telephoto end of the zoom lens according to Example 3 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 6 is a lens configuration diagram of a zoom lens according to Example 4 of the present invention. These are various aberrations when focusing on infinity at the wide angle end (f = 51.47 mm) of the zoom lens according to Example 4 of the present invention. These are various aberrations when focusing at infinity at the intermediate focal length (f = 100.00 mm) of the zoom lens according to Example 4 of the present invention. These are various aberrations when focusing on infinity at the telephoto end (f = 193.95 mm) of the zoom lens according to Example 4 of the present invention. FIG. 9 is a lateral aberration diagram at normal time at infinite focus at the wide angle end of the zoom lens according to Example 4 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm about the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram at normal time at infinite focus at the telephoto end of the zoom lens according to Example 4 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm about the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 6 is a lens configuration diagram of a zoom lens according to Example 5 of the present invention. These are various aberrations when focusing on infinity at the wide angle end (f = 51.57 mm) of the zoom lens according to Example 5 of the present invention. These are various aberrations when focusing at infinity at the intermediate focal length (f = 99.97 mm) of the zoom lens according to Example 5 of the present invention. These are various aberrations when focusing on infinity at the telephoto end (f = 193.92 mm) of the zoom lens according to Example 5 of the present invention. FIG. 9 is a lateral aberration diagram at normal time with infinite focus at the wide-angle end of a zoom lens according to Example 5 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis. FIG. 9 is a lateral aberration diagram at normal time with infinite focus at the telephoto end of the zoom lens according to Example 5 of the present invention, and a lateral aberration diagram at the time of image stabilization in which the image stabilization lens unit is moved by +0.3 mm along the optical axis. FIG. 6 is a lateral aberration diagram during vibration isolation when the vibration isolation lens group is moved by −0.3 mm along the optical axis.

Explanation of symbols

S Aperture stop I Image plane Gr1 First lens group Gr1a 1a lens group Gr1b 1b lens group Gr2 Second lens group Gr3 Third lens group Gr4 Fourth lens group cc line (wavelength λ = 656.3 nm)
dd line (wavelength λ = 587.6 nm)
g g line (wavelength λ = 435.8 nm)
Y image height ΔS sagittal image plane ΔM main Li Jionaru image plane

Claims (5)

From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having a positive refractive power;
By changing the distances between the lens groups have rows zooming, the first lens group is a inner focus type of anti-vibration lens which moves to the object side along with the zooming telephoto end from the wide-angle end,
The first lens group includes a fixed first a lens group that does not move during focusing, and a first b lens group that performs focusing by moving the optical axis toward the object side when focusing from infinity to a close object. Consisting of
The second lens group can move in a direction substantially perpendicular to the optical axis, thereby moving the image in a direction substantially perpendicular to the optical axis,
An inner focus type vibration-proof lens that satisfies the following conditional expression:
0.30 <| f2 / fw | <0.45 (1)
f2 represents the focal length fw of the second lens group, and the focal length of the entire system at the wide-angle end. From the object side,
A first lens group having a positive refractive power;
A second lens group having negative refractive power;
A third lens group having positive refractive power;
A fourth lens group having a positive refractive power;
By changing the distances between the lens groups have rows zooming, the first lens group is a inner focus type of anti-vibration lens which moves to the object side along with the zooming telephoto end from the wide-angle end,
The first lens group includes a fixed first a lens group that does not move during focusing, and a first b lens group that performs focusing by moving the optical axis toward the object side when focusing from infinity to a close object. Consisting of
The second lens group can move in a direction substantially perpendicular to the optical axis, thereby moving the image in a direction substantially perpendicular to the optical axis,
The fourth lens group includes, in order from the object side, a lens having a positive refractive power, a lens having a positive refractive power, and a lens having a negative refractive power. The lens having a negative refractive power is a cemented lens. An inner focus type anti-vibration lens characterized by The inner focus type vibration-proof lens according to claim 1, wherein the following conditional expression is satisfied.
−1.20 <f1 / R2 <−0.30 (2)
f1 is the focal length of the first lens group R2 is the radius of curvature of the most object-side surface of the second group The inner focus type vibration-proof lens according to any one of claims 1 to 3, wherein the following conditional expression is satisfied.
3.00 <| f1 / f2 | <4.50 (3)
f1 is the focal length of the first lens group f2 is the focal length of the second lens group The first b lens group includes at least one lens having a positive refractive power, wherein the Abbe number of the positive refractive power lens at the d-line is ν1b, and the following conditional expression is satisfied. Item 5. The inner focus type vibration-proof lens according to any one of Items 1 to 4.
ν1b> 70.00 (4)

Images