JP3428209B2 - Short distance correction lens with anti-shake function - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short-distance correction lens having a vibration-proof function, and more particularly to a vibration-proof method for a short-distance correction lens (so-called microlens or macrolens).

[0002]

2. Description of the Related Art Conventionally, as disclosed in JP-A-1-189621, JP-A-1-191112, and JP-A-1-191113, the shooting distance is infinity or a distance close to infinity (shooting magnification). (It is close to 0)
In some cases, the entire lens group or a part of the lens group is moved in a direction substantially orthogonal to the optical axis to correct a change in image position due to camera shake or the like. In this specification, moving the lens group in a direction substantially orthogonal to the optical axis to correct a change in image position due to camera shake or the like is referred to as “anti-vibration”.

[0003]

However, with the conventional technique as described above, image stabilization cannot be performed in a sufficiently large photographing magnification (for example, -1/2 times), and even if the photographing magnification is equal to (-). There is an inconvenience that the image stabilization cannot be performed near the (1 ×) state. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a short-distance correction lens having a vibration-proof function, small size, and high performance, which is suitable for photography, video, and the like. .

[0004]

In order to solve the above problems, in the present invention, a first lens group G1 having a positive refractive power is provided on the most object side, and an image of the first lens group G1 is formed. Has a second lens group G2 having negative refractive power on the side,
A final lens group GL having a positive refractive power is provided on the most image side, and the distance between the first lens group G1 and the second lens group G2 increases when focusing on an object at infinity from a short distance.
In a short-distance correction lens in which the photographing magnification βM at the shortest photographing distance satisfies 0.25 <| βM |, a partial lens group GLP having a negative refractive power in the final lens group GL is almost aligned with the optical axis. Displacement means for moving in a direction orthogonal to each other for vibration isolation is provided, and the focal length of the final lens group GL.
Is fL, and the partial lens in the final lens group GL is
The focal length of the group GLP is fLP, and the infinity shooting state
The focal length of the entire lens system is f, and the partial lens group G
Provide a short-distance correction lens characterized by satisfying the condition of 0.2 <-fLP / fL <10.0 L / f <0.25 , where L is the thickness of the LP along the optical axis. To do.

According to a preferred embodiment of the present invention, the focal length of the final lens group GL is fL, the focal length of the partial lens group GLP in the final lens group GL is fLP, and the entire lens system in the infinity photographing state is used. Let f be the focal length of
When the magnitude of the maximum displacement amount of the partial lens group GLP in the direction orthogonal to the optical axis at the time of image stabilization is ΔSLP, 0.2 <fL / f <5.0 ΔSLP / | fLP | <0 The condition of 1 is satisfied.

[0006]

In the present invention, the first lens group G1 having a positive refracting power and the image of the first lens group G1 are suitable for a short-distance correction lens having a relatively long focal length for photography, video, etc. Side second lens group G2 having negative refractive power
And a final lens group GL having a positive refracting power disposed closest to the image side, and at the time of focusing from an infinite object to a short-distance object, the distance between the first lens group G1 and the second lens group G2. Is adopted. As a reason for adopting this configuration in the present invention, the features and advantages of this type of short-distance correction lens will be briefly described.

First, with the short-distance correction lens having the above-mentioned configuration, not only in the infinity photographing state, but -1 /
Good imaging performance can be obtained even at each photographing magnification including 2 times or 1 × (-1). Further, since the second lens group G2 has a negative refractive power and the combined principal point of the first lens group G1 and the second lens group G2 can be located closer to the object side than the first lens group G1, it is made compact. Is advantageous to. Furthermore, the amount of movement of the second lens group G2 when focusing on an object at infinity to a short-distance object can be made smaller than that of the conventionally used front lens paying-out method. This is advantageous.

In addition, the action of the negative refracting power of the second lens group G2 allows the entire Petzval sum to be well balanced, which is advantageous for aberration correction. The present invention has found optimum conditions for image stabilization in such a short-distance correction lens suitable for photography and video.

The conditions of the present invention will be described in detail below. In the short-distance correction lens of the type described above, the first lens group G
1 is the largest. Therefore, if the first lens group G1 is an anti-vibration correction optical system that is displaced in a direction orthogonal to the optical axis for anti-vibration, the holding mechanism and the drive mechanism become complicated and large in size, which is not preferable. Further, when performing short-distance correction, that is, focusing on an object at a short distance from infinity, the second lens group G2 moves along the optical axis. Therefore, it is not preferable to use the image stabilization optical system in which the second lens group G2 is displaced in the direction orthogonal to the optical axis, because the holding mechanism and the driving mechanism become complicated and large.

Therefore, in the present invention, the lens group closest to the image side, that is, the final lens group GL, is used because of the simplification of the mechanism of the entire lens system and the excellent aberration characteristics during image stabilization.
Among them, a construction is adopted in which a displacement means is provided in a partial lens group GLP having a negative refracting power to perform image stabilization. Less than,
The partial lens group GLP is called an "anti-vibration lens group". If a fixed flare diaphragm is provided on the optical axis in addition to the aperture diaphragm,
For image stabilization, unnecessary light rays can be blocked when the image stabilization lens group GLP is displaced across the optical axis, and ghost occurrence and unnecessary exposure can be avoided.

The short-distance correction lens of the present invention satisfies the following conditional expression (1) in addition to the above configuration. 0.25 <| βM | (1) where βM: shooting magnification at the shortest shooting distance

Conditional expression (1) shows the short-distance focusing ability of the optical system according to the present invention as a short-distance correction lens, and at the same time, an appropriate range () for the magnitude of the photographing magnification at the shortest photographing distance for practical use. The lower limit) is specified. If the lower limit of conditional expression (1) is not reached, the shooting magnification at the shortest shooting distance becomes too small, and the short-distance focusing ability becomes insufficient, making it unsuitable for practical use.

Further, in order to obtain better imaging performance, it is preferable that the following conditional expressions (2) and (3) are satisfied. 0.2 <fL / f <5.0 (2) ΔSLP / | fLP | <0.1 (3)

Here, fL: focal length of the final lens group GL f: focal length of the entire lens system in the infinity photographing state fLP: focal length of the image stabilizing lens group GLP in the final lens group GL ΔSLP: during image stabilization Of the maximum displacement of the image stabilization lens group GLP in the direction orthogonal to the optical axis

Conditional expression (2) defines an appropriate range for the ratio between the focal length of the final lens group GL and the focal length of the entire short-distance correction lens in the infinity photographing state.
If the upper limit of conditional expression (2) is exceeded, not only does the overall length increase, which is against compactness, but spherical aberration tends to become excessive on the negative side, which is inconvenient.

On the contrary, when the value goes below the lower limit of the conditional expression (2), the focal length of the final lens group GL becomes too small, and spherical aberration tends to become excessive on the positive side in the infinity photographing state, so that the short distance. The fluctuation of the field curvature at the time of focusing becomes great. In addition, the Petzval sum tends to be greatly displaced to the positive side,
As a result, the curvature of the image surface is likely to occur in the negative direction, which is inconvenient. By setting the lower limit value of conditional expression (2) to 0.4 and the upper limit value to 3.0, it is possible to obtain better imaging performance.

Conditional expression (3) is defined by the magnitude ΔSLP of the maximum displacement amount of the image stabilizing lens group GLP during image stabilization.
An appropriate range is defined by the ratio of the focal length fLP of LP.
If the upper limit of conditional expression (3) is exceeded, the maximum displacement amount of the image stabilization lens group GLP in the final lens group GL during image stabilization becomes too large, and as a result, the amount of aberration fluctuation during image stabilization will become large. Since it becomes large, it is inconvenient. In particular, at the peripheral position on the image plane, the difference in the optical axis direction between the best image plane in the meridional direction and the best image plane in the sagittal direction widens, which is inconvenient. If the upper limit of conditional expression (3) is set to 0.03, even better imaging performance can be obtained.

In the present invention, the following conditional expression (4)
It is preferable that both and (5) are satisfied. WD / f <5.0 (4) 0 <Δ / f <0.5 (5) where WD: axial distance between the subject and the lens surface closest to the object at the shortest shooting distance Δ: infinity shooting state From the first to the shortest shooting distance
Amount of change in axial air gap between the lens G1 and the second lens group G2 (when increasing, it is positive)

Conditional expression (4) expresses the short-distance focusing ability of the short-distance correction lens, and the axial distance (W between the object surface and the lens surface closest to the object at the shortest shooting distance).
With regard to D), a practically applicable range is specified. If the upper limit of conditional expression (4) is exceeded, the distance WD to the subject at the shortest shooting distance becomes too large, and the short-distance focusing ability becomes insufficient, making it unsuitable for practical use.

Conditional expression (5) expresses the amount of change in the axial air gap between the first lens G1 and the second lens group G2 that occurs when focusing from the infinity shooting state to the shortest shooting distance. It defines the appropriate range. If the upper limit of conditional expression (5) is exceeded, the amount of movement of the second lens group G2 becomes too large. As a result, the amount of aberration variation at the time of focusing at a short distance becomes large, which is inconvenient. In particular, spherical aberration, and image plane bending and astigmatism at peripheral positions on the image plane are extremely large, which is inconvenient. Moreover, the structure is mechanically complicated, which is not preferable.

Further, in the present invention, it is desirable that the following conditional expressions (6) and (7) are satisfied. 0.2 <| fLP | / fL <10.0 (6) L / f <0.25 (7) where, L is the axial thickness of the antivibration lens group GLP.

When the value goes below the lower limit of conditional expression (6), the focal length of the image stabilizing lens unit GLP becomes too small, the spherical aberration becomes negatively excessive, and the curvature of the image surface becomes negative. It tends to occur in the direction, which is inconvenient. In addition, the fluctuations of various aberrations during image stabilization become excessive, and it becomes difficult to obtain good imaging performance during image stabilization.

On the contrary, when the upper limit of conditional expression (6) is exceeded,
In both the infinity shooting state and the short distance shooting state, spherical aberration is likely to be positively excessive and distortion aberration is increased to the positive side, which is inconvenient. By setting the upper limit value of conditional expression (6) to 5.0 and the lower limit value to 0.6, it is possible to obtain better imaging performance.

If the upper limit of conditional expression (7) is exceeded, the axial thickness of the image stabilizing lens group GLP (along the optical axes of the most object side surface and the most image side surface of the image stabilizing lens group GLP) is satisfied. This is inconvenient because the distance) becomes too large and the mechanism for vibration isolation becomes large and complicated.

When actually constructing the final lens group GLP, it is desirable that the following conditional expressions (8) and (9) are satisfied. 1.5 <N- (8) 35 <ν- (9) where N-: maximum value of the refractive index of the negative lens component in the image stabilizing lens group GLP ν-: in the image stabilizing lens group GLP Maximum value of Abbe number of negative lens component Note that N- and ν- are d-line (λ = 587.6 nm)
Shows the refractive index and the Abbe number with respect to.

When the value goes below the lower limit of the conditional expression (8), the spherical aberration tends to be excessive on the positive side and the distortion aberration increases on the positive side in both the infinity photographing state and the short distance photographing state. It is inconvenient. In addition, the Petzval sum also tends to shift to the negative side, so that the curvature of the image surface tends to increase in the positive direction, which is inconvenient.

When the value goes below the lower limit of the conditional expression (9), the axial chromatic aberration of short wavelength tends to be excessive on the positive side in both the infinity photographing state and the short-distance photographing state, resulting in good image formation. It becomes difficult to obtain performance.

Further, the following conditions are also important for obtaining good image forming performance and image stabilizing performance. First, in order to simplify the configurations of the holding mechanism and the drive mechanism, it is desirable that the vibration-proof lens group GLP be fixed along the optical axis when focusing on a short distance. When the image stabilizing lens group GLP is composed of a single lens, it is desirable to dispose the image stabilizing lens group GLP on the image side of the aperture stop.

Further, in order to construct the entire short-distance correction lens, the distribution of the refractive power between the first lens group G1 and the second lens group G2 is important, and it is desirable to satisfy the following conditional expression (10). 1.2 <f1 / | f2 | <2.0 (10) where, f1: focal length of the first lens group G1 in the infinity shooting state f2: focal length of the second lens group G2 in the infinity shooting state

In order to obtain even better imaging performance, it is desirable to provide an aperture stop near the second lens group G2 or near the third lens group G3, and the vibration-proof lens group GLP is better than the aperture stop. It is desirable to be placed on the image side. When the optical system of the present invention is configured by three lens groups, that is, the first lens group G1 having a positive refractive power, the second lens group G2 having a negative refractive power, and the final lens group GL having a positive refractive power, the second lens It is desirable to configure a substantially parallel system between the group G2 and the final lens group GL.

Further, if the first lens group G1 is divided into a plurality of partial lens groups and the air distance of each partial lens group is changed so as to perform short-distance focusing, further excellent imaging performance can be obtained. (See the second embodiment described later). Second
When actually forming the lens group G2, it is preferable that the lens group G2 includes two or more lens components having negative refracting power.

When the image stabilizing lens group GLP is located on the image side of the center of the final lens group GL on the optical axis,
This is preferable because the fluctuation of spherical aberration during vibration reduction becomes small. When actually constructing the final lens group GL, it is desirable to dispose a cemented lens composed of a negative lens and a positive lens on the most object side.

Further, as the focal length and the photographing magnification become larger, the depth on the side of the field becomes shallower, so that there is a disadvantage that the focus tends to be out of focus. In this case, by combining the autofocus system and the short distance correction lens of the present invention, it is possible to avoid the defocus.

[0034]

EXAMPLES In each of the examples, the short-distance correction lens having the image stabilizing function according to the present invention has a first lens group G1 having a positive refractive power on the most object side, and the first lens group G1 is provided.
Has a second lens group G2 having a negative refractive power on the image side, and a final lens group GL having a positive refractive power on the most image side.
When focusing from infinity to a short-distance object, the distance between the first lens group G1 and the second lens group G2 increases. Further, there is provided a displacement means 1 for moving a part of the partial lens group GLP having a negative refracting power in the final lens group GL in a direction substantially orthogonal to the optical axis for vibration isolation.

Each embodiment of the present invention will be described below with reference to the accompanying drawings. [Embodiment 1] FIG. 1 is a diagram showing the structure of a short-distance correction lens according to the first embodiment of the present invention. The illustrated short-distance correction lens includes a biconvex lens, a biconvex lens, and
And a first lens group G1 composed of a biconcave lens, a cemented lens of a negative meniscus lens having a concave surface facing the object side and a biconcave lens, and a cemented lens of a negative meniscus lens having a concave surface facing the object side and a biconcave lens The second consisting of
And a third lens group GL including a cemented lens of a biconcave lens and a biconvex lens, a positive meniscus lens having a convex surface facing the object side, and a negative meniscus lens having a convex surface facing the object side. There is. Incidentally, the negative meniscus lens having the convex surface facing the object side in the third lens group GL constitutes the image stabilizing lens group GLP. An aperture stop S is provided in the third lens group G3 as shown in the figure.

FIG. 1 shows the positional relationship between the lens groups in the infinity shooting state. When focusing on a short-distance object, the second lens group G2 moves along the optical axis along the trajectory shown by the arrow in the figure. Moving. However, the first lens group G1 and the third lens group GL are fixed in the optical axis direction during focusing. A part of the third lens group GL, that is, the anti-vibration lens group GLP is appropriately moved in a direction substantially orthogonal to the optical axis by the anti-vibration mechanism 1 which is a displacement means, and image shake caused by camera shake or the like is corrected. It has become so. Example 1 is an application of the present invention to a photographic lens having a relatively long focal length.

The following table (1) lists the values of specifications of the first embodiment of the present invention. In Table (1), f is the focal length in the infinity shooting state, β is the shooting magnification in the close-up shooting state, FNO is the F number in the infinity shooting state,
2ω represents the angle of view in the infinity shooting state, and Bf represents the back focus. Furthermore, the leftmost number is the order of the lens surfaces from the object side, r is the radius of curvature of each lens surface, d is the distance between the lens surfaces, and n (D) and ν are d lines (λ = 587. 6 nm) and the Abbe number, and n (G) shows the refractive index for the g-line (λ = 435.8 nm).

[0038]

[Table 1] f = 200 FNO = 4.03 2ω = 12.2 ° rd ν n (D) n (G) 1 106.1200 8.1000 70.08 1.52000 1.52908 2 -244.4800 0.5000 3 97.6400 8.5000 70.08 1.52000 1.52908 4 -107.2300 0.7000 5 -103.7400 2.4000 30.05 1.69895 1.72942 6 1192.6898 (d6 = variable) 7 -110.5700 4.0000 28.34 1.72825 1.76206 8 -55.6700 2.0000 64.20 1.51680 1.52667 9 210.7400 2.5000 10 -211.9600 2.0000 28.34 1.72825 1.76206 11 -97.7000 2.0000 64.12 53.1680 1.5667 (variable) ) 13 -140.6472 1.5000 35.59 1.59507 1.61681 14 84.3489 5.0000 58.54 1.61272 1.62571 15 -58.5014 45.2000 16 99.1934 6.0000 60.14 1.62041 1.63317 17 57107.6970 10.0000 18 172.1229 2.5000 49.45 1.77279 1.79232 19 79.4832 (Bf) (variable interval at focusing) 200. -0.50000 d6 22.29075 47.29075 d12 29.58233 4.58233 Bf 65.4727 65.4727 (Vibration stabilization data) Infinity shooting magnification -1/2 Movement amount of the vibration reduction lens group in the direction orthogonal to the optical axis (mm) 1.501 50 Image movement amount (mm) −0.498 −0.498 (The negative sign of the image movement amount indicates that it is the opposite direction to the lens movement direction) (Condition corresponding value) βM = −0.5 f = 200.0 fL = 120.0 fLP = -474.9 f1 = 100.0 f2 = -60.0 WD = 499.076 Δ = 25.0 L = 6.0 (1) | βM | = 0. 5 (2) fL / f = 0.6 (3) ΔSLP / | fLP | = 0.0032 (4) WD / f = 2.4954 (5) Δ / f = 0.1250 (6) -fLP / fL = 3.958 (7) L / f = 0.03 (8) N- = 1.77279 (9) ν- = 49.5 (10) f1 / | f2 | = 1.667

FIGS. 2 and 3 are graphs showing various aberrations in the infinity photographing condition and those in the photographing magnification of -1/2. In each aberration diagram, FNO is F
No., Y is the image height, NA is the numerical aperture, D is the d-line (λ = 587.6 nm), and G is the g-line (λ = 435.8).
nm) respectively. Further, in the aberration diagram showing astigmatism, the solid line shows the sagittal image plane and the broken line shows the meridional image plane. As is clear from each aberration diagram, in the present embodiment, it is understood that various aberrations are well corrected in each shooting distance state, including during image stabilization.

[Embodiment 2] FIG. 4 is a diagram showing the structure of a short-distance correction lens according to a second embodiment of the present invention. The illustrated short-distance correction lens includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex lens, a positive meniscus lens having a convex surface facing the object side, and a convex surface facing the object side. A first lens group G1 including a cemented lens of a negative meniscus lens and a positive meniscus lens having a convex surface facing the object side, a negative meniscus lens having a convex surface facing the object side, and a positive meniscus lens having a convex surface facing the object side And a second lens group G2 including a cemented lens of a positive meniscus lens having a concave surface facing the object side and a biconcave lens, and a negative meniscus lens having a convex surface facing the object side and a biconvex lens. From a third lens group GL including a compound lens, a negative meniscus lens having a concave surface facing the object side, and a positive meniscus lens having a convex surface facing the object side. It has been made. The third lens group GL
Among them, the negative meniscus lens having a concave surface facing the object side constitutes the antivibration lens group GLP. Further, as shown in the figure, an aperture stop S is provided between the second lens group G2 and the third lens group G3, and a flare stop FS is provided in the third lens group G3.

FIG. 4 shows the positional relationship between the lens groups in the infinity photographing state. When focusing on a short-distance object, the front group of the first lens group G1 and the second lens group G2 are indicated by arrows in the figure. It moves on the optical axis along the orbit shown. However, the rear group of the first lens group G1 and the third lens group GL are fixed in the optical axis direction during focusing. A part of the third lens group GL, that is, the anti-vibration lens group GLP is appropriately moved in a direction substantially orthogonal to the optical axis by the anti-vibration mechanism 1 which is a displacement means, and image shake caused by camera shake or the like is corrected. It has become so. Example 2 also applies the present invention to a photographic lens having a relatively long focal length.

The following table (2) lists the values of specifications of the second embodiment of the present invention. In Table (2), f is the focal length in the infinity shooting state, β is the shooting magnification in the close-up shooting state, FNO is the F number in the infinity shooting state,
2ω represents the angle of view in the infinity shooting state, and Bf represents the back focus. Further, the leftmost number is the order of the lens surfaces from the object side, r is the radius of curvature of each lens surface, d is the distance between the lens surfaces, and n (D) and ν are d lines (λ = 587. 6 nm) and the Abbe number, and n (G) shows the refractive index for the g-line (λ = 435.8 nm).

[0043]

[Table 2] f = 200 FNO = 4.07 2ω = 12.23 ° rd ν n (D) n (G) 1 197.73830 2.50000 33.89 1.80384 1.83464 2 85.60980 7.00000 82.52 1.49782 1.50527 3 -206.28280 0.30000 4 71.60670 6.00000 82.52 1.49782 1.50527 5 431.05366 (d5 = variable) 6 79.01680 2.50000 40.90 1.79631 1.82107 7 39.95540 8.80000 60.64 1.60311 1.61540 8 478.74200 (d8 = variable) 9 196.43220 2.00000 57.03 1.62280 1.63639 1061.3901.105. -58.94500 2.00000 60.14 1.62041 1.63317 14 49.16280 (d14 = variable) 15 1206.18340 2.00000 31.08 1.68893 1.71783 16 69.60550 6.00000 60.14 1.62041 1.63317 17 -59.17280 46.50000 18 -72.76840 2.50000 49.45 1.77279.79232 19 -436.14210 6.0000 4586.793279 1.79232 19 -436.14210 0.40000 45. ) (Variable interval when focusing) f, β 199.99680 -0.50000 -1.00000 d5 6.64330 14.20990 6.64330 d8 5.14048 17.75138 37.14078 d14 45.12496 32.514 06 13.12466 Bf 58.809 58.809 58.809 (Vibration stabilization data) Infinity shooting magnification Shooting magnification −1/2 −1 Moving amount of anti-vibration lens group in the direction orthogonal to the optical axis (mm) 0.70 0.70 0.70 Image movement Amount (mm) -0.396 -0.396 -0.396 (The negative sign of the amount of movement of the image indicates that it is the direction opposite to the moving direction of the lens) (Condition corresponding value) βM = -1.0 f = 200.0 fL = 120.0 fLP = −113.36 f1 = 80.0 f2 = −48.0 WD = 272.364 Δ = 32.0 L = 6.0 (1) | βM | = 1. 0 (2) fL / f = 0.600 (3) ΔSLP / | fLP | = 0.0062 (4) WD / f = 1.3618 (5) Δ / f = 0.16 (6) -fLP / fL = 0.945 (7) L / f = 0.03 (8) N- = 1.77279 (9) ν- = 9.5 (10) f1 / | f2 | = 1.667

FIGS. 5 to 7 are graphs showing various aberrations in the infinity photographing state, various kinds of aberrations in the state where the photographing magnification is −1/2, and various aberrations in the state where the photographing magnification is −1. . In each aberration diagram, FNO is the F number, Y is the image height, NA is the numerical aperture, and D is the d-line (λ = 58).
7.6 nm) and G indicates the g-line (λ = 435.8 nm). Further, in the aberration diagram showing astigmatism, the solid line shows the sagittal image plane and the broken line shows the meridional image plane. As is clear from each aberration diagram, in the present embodiment, it is understood that various aberrations are well corrected in each shooting distance state, including during image stabilization.

[0045]

As described above, according to the present invention, it is possible to provide a small-sized, high-performance short-distance correction lens suitable for photography and video, which is provided with a vibration-proof function. For this reason, hand-held photography becomes possible, which is extremely convenient at the time of actual photography, and photography can also be performed with good imaging performance under vibration conditions caused by camera shake or the like.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a short-distance correction lens according to Example 1 of the present invention.

FIG. 2 is a diagram of various types of aberration in the first embodiment at infinity imaging.

FIG. 3 is a diagram of various types of aberration in the state where the imaging magnification of the first example is −1/2.

FIG. 4 is a diagram showing a configuration of a short-distance correction lens according to Example 2 of the present invention.

FIG. 5 is a diagram of various types of aberration of the second example in the infinity shooting state.

FIG. 6 is a diagram of various types of aberration in a state where the imaging magnification of the second example is −1/2.

FIG. 7 is a diagram of various types of aberration when the imaging magnification of the second example is −1 ×.

[Explanation of symbols]

G1 first lens group G2 Second lens group GL final lens group GLP anti-vibration lens group 1 Displacement means (anti-vibration mechanism) S aperture stop

Claims (6)

(57) [Claims] 1. A first object having a positive refractive power on the most object side.
It has a lens group G1, a second lens group G2 having a negative refractive power on the image side of the first lens group G1, and a final lens group GL having a positive refractive power on the most image side. However, when focusing on an object at a short distance from infinity, the first lens group G
In the short-distance correction lens in which the distance between the first lens group G2 and the second lens group G2 increases and the shooting magnification βM at the shortest shooting distance satisfies 0.25 <| βM | Displacement means is provided for moving part of the partial lens group GLP having power in a direction substantially orthogonal to the optical axis for vibration isolation. The focal length of the final lens group GL is fL, and the final lens group GL is the final lens group GL.
The focal length of the partial lens group GLP in the lens group GL is f
LP, the focal length of the entire lens system when shooting at infinity
The distance is f, and the thickness of the partial lens group GLP along the optical axis
When a is L, the short-range correction lens satisfies the 0.2 <-fLP / fL <10.0 L / f <0.25 condition. 2. The short-distance correction lens according to claim 1, wherein the partial lens group GLP in the final lens group GL is fixed along the optical axis when focusing on a short distance. 3. The focal length of the final lens group GL is fL
And then, the partial lens group GLP in the last lens group GL
And f is the focal length of the entire lens system in the infinity shooting state, and ΔSLP is the maximum displacement amount in the direction orthogonal to the optical axis of the partial lens group GLP during image stabilization. The short-distance correction lens according to claim 1 or 2, wherein the condition: 0.2 <fL / f <5.0 ΔSLP / | fLP | <0.1 is satisfied. 4. The shortest distance from the infinity shooting state is defined as WD, where WD is the distance between the subject and the lens surface closest to the object at the shortest shooting distance along the optical axis, and f is the focal length of the entire lens system in the infinity shooting state. When the amount of change in the axial air gap between the first lens G1 and the second lens group G2 when focusing on the shooting distance is Δ (when increasing, is positive), WD / f <5. The short-distance correction lens according to any one of claims 1 to 3, wherein the condition 0 0 <Δ / f <0.5 is satisfied. 5. A negative lens component in the partial lens group GLP.
The maximum value of the refractive index of
The maximum value of the Abbe number of the negative lens component in GLP is ν-
In this case, the short-distance correction lens according to any one of claims 1 to 4, wherein the condition of 1.5 <N- 35 <ν- is satisfied. 6. The partial lens in the final lens group GL.
Group GLP moves in a direction almost orthogonal to the optical axis for vibration isolation
Fixed flare diaphragm to block unwanted rays when
Are provided on the optical axis.
The short-distance correction lens according to any one of 1.