JPH11231220A - Optical magnification system having vibration proofing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical magnification system having vibration proofing function so as to provide a still image by optically correcting the blur of a photographed image in the case of vibrating the optical magnification system by satisfying specified conditions between the wide angle end and telescopic end of adjacent lens groups. SOLUTION: This system has a first group L1 having negative refracting power, a second group L2 having positive refracting power, a third group L3 having negative refracting power and a fourth group L4 having positive refracting power and performs a magnification while changing the intervals of the respective lens groups. Then, the third lens group L3 is composed of plural lens groups (third (a) group L3a and third (b) group L3b, for example,) and one part of lens groups is moved vertically with an optical axis so that the blur of the photographed image in the case of vibrating the optical magnification system can be corrected. In this case, when an interval between the wide angle end and telescopic end of (i)th and (i+1)th groups is defined as Di, the conditions of D1W>D1T, D2W<D2T and D3W>DST are satisfied. At such a time, a diaphragm SP is arranged just before the third group L3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable power optical system having an image stabilizing function, and more particularly to a variable power optical system by moving a part of a lens group of the variable power optical system in a direction perpendicular to an optical axis. A camera suitable for a photographic camera, an electronic still camera, a video camera, or the like that stabilizes the captured image by optically correcting a blur of the captured image when the camera is vibrated (tilted) to obtain a still image. The present invention relates to a variable power optical system having a vibration function.

[0002]

2. Description of the Related Art When an image is taken from a moving object such as a car or an aircraft in progress, vibration is transmitted to an image taking system, resulting in camera shake and blurring of the taken image. Blurred captured images occur particularly frequently in a telephoto lens system having a long focal length of the imaging system.

Conventionally, various variable power optical systems having an image stabilizing function having a function of preventing blurring of a photographed image at this time have been proposed.

For example, in Japanese Patent Laid-Open Publication No. Hei 5-232410, the first to fourth refractive powers of positive, negative, positive, and positive refractive powers are sequentially described from the object side.
In a telephoto zoom lens having four lens groups, the second group is moved in a direction perpendicular to the optical axis to perform image stabilization.

In Japanese Patent Application Laid-Open No. 7-152002, a third lens unit of a zoom lens having four lens units of first to fourth units having negative, positive, negative, and positive refractive powers in order from the object side is disclosed. Is moved in the direction perpendicular to the optical axis to perform vibration isolation.

In Japanese Patent Application Laid-Open No. 7-199124, positive, negative,
In a variable power optical system having a four-unit configuration including four lens units having positive and positive refractive power, the entire third unit is vibrated in a direction perpendicular to the optical axis to perform image stabilization.

[0007]

Generally, in a vibration-proof optical system for performing vibration reduction by decentering some lenses of a photographing system in a direction perpendicular to the optical axis, a special optical system is used for vibration reduction. The advantage is that no system is required.

However, this method requires a space for a lens to be moved and has a problem that the amount of eccentric aberration generated during image stabilization increases.

According to the present invention, a relatively small and light lens group constituting a part of a variable power optical system is moved in a direction perpendicular to the optical axis, and an image obtained when the variable power optical system vibrates (tilts). When correcting blur, when the lens units of each lens unit are decentered while appropriately reducing the load on the driving unit by reducing the size of the entire apparatus, simplifying the mechanism, and reducing the load on the driving unit It is an object of the present invention to provide a variable power optical system having an anti-shake function with a shooting angle of view of about 73 degrees at the wide-angle end and a zoom ratio of about 3, in which the amount of eccentricity is reduced and the eccentric aberration is satisfactorily corrected.

[0010]

According to the present invention, a variable power optical system having an image stabilizing function includes: (1-1) a first unit having a negative refractive power, a second unit having a positive refractive power, The zoom lens has four lens units, a third unit having a negative refractive power and a fourth unit having a positive refractive power, and performs zooming by changing the distance between the lens units. The third unit is composed of a plurality of lens units. Then, by moving some of the lens units SL in the direction perpendicular to the optical axis to correct the blur of the photographed image when the variable power optical system vibrates, the wide-angle end of the i-th unit and the i + 1-th unit and the telephoto end are corrected. D1W> D1T (1) D2W <D2T (2) D3W> D3T (3) When the distance at the end is Di.

[0011]

1 to 7 are sectional views of a lens at a wide angle end according to Numerical Examples 1 to 7 of the present invention which will be described later.

In the figure, L1 is a first lens unit having a negative refractive power, L2 is a second lens unit having a positive refractive power, L3 is a third lens unit having a negative refractive power, and L4 is a negative lens.
Denotes a fourth group having a positive refractive power. The third lens unit L3 has two lens units, a third lens unit L3a having a negative refractive power and a third lens unit L3b having a negative refractive power. SP is an aperture.

Numerical embodiments 1 of FIGS. 1, 4, 5 and 6
At the time of zooming from the wide-angle end to the telephoto end, the first unit L1 is moved so as to have a locus convex on the image surface side as indicated by an arrow in the zoom lens units 4, 5, and 6, and the second unit L2 to the fourth unit L4 is moved to the object side.

In the numerical examples 1 and 5 shown in FIGS. 1 and 5, the distance between the third lens unit and the third lens unit is also changed at the time of zooming, and the aberration fluctuation at the time of zooming is satisfactorily corrected. .

Numerical Examples 2, 3, and 7 in FIGS. 2, 3, and 7
In zooming from the wide-angle end to the telephoto end, the third lens unit is fixed, the first lens unit L1 is moved so as to have a convex locus on the image surface side, and the second lens unit and the fourth lens unit are moved toward the object side. It is moving.
In each numerical example, the second unit and the fourth unit are moved integrally.

During zooming, the stop SP is moved integrally with the third lens unit L3. In the drawing, P represents a dummy plane used for design.

In the present embodiment, the third lens unit L3 is composed of a plurality of lens units (two lens units in the figure, but two or more lens units may be used). The large lens group SL is moved in the direction perpendicular to the optical axis to correct image blurring when the variable power optical system vibrates.

In the numerical embodiments 1 to 4 shown in FIGS.
The group is moved substantially perpendicular to the optical axis direction to perform vibration isolation,
In Numerical Examples 5 to 7 shown in FIGS. 5 to 7, the 3a group is moved substantially perpendicularly to the optical axis direction to perform image stabilization. Numerical embodiments 1 to 7 in FIGS. 1 to 7 are effective screen dimensions (image circles).
φ is 43.27. The diaphragm SP is fixed during vibration isolation.

In the present embodiment, the stop SP is disposed immediately before the third lens unit L3, and is moved together with the third lens unit during zooming, thereby reducing aberration fluctuations caused by the movable lens unit. Further, by reducing the distance between the lens groups in front of the stop toward the telephoto side, the diameter of the front lens can be easily reduced. Focusing is performed by moving the first group, but may be performed using another lens group.

The variable power optical system having the vibration proof function of the present invention comprises:
By setting the respective lens groups during zooming and image stabilization as described above, and satisfying conditional expressions (1) to (3), a predetermined zoom ratio is effectively ensured, and this occurs during image stabilization. Good optical performance is obtained at the standard time (when no image stabilization is performed) and at the time of image stabilization by reducing eccentric aberration.

Next, the technical meaning of each of the above conditional expressions will be described.

Conditional expressions (1) to (3) set the moving conditions of each lens unit having a predetermined refractive power when changing the magnification from the wide-angle end to the telephoto end. The size of the entire lens system is reduced while effectively ensuring

The variable power optical system having the image stabilizing function of the present invention is realized by satisfying the above conditions. However, in order to further reduce the overall length of the lens and achieve good optical performance. Preferably satisfies at least one of the following conditions.

(A-1) A fixed stop is provided on the object side or image plane side of the third lens unit or in the lens system at the time of image stabilization.

Thus, the outer diameters of the first and fourth lens units are reduced, and aberrations are corrected in a well-balanced manner.

(A-2) The third lens unit is a third lens unit having a negative refractive power.
It is composed of two lens groups, a group and a 3b group having a negative refractive power. Of these, the lens group having the larger absolute value of the parallel eccentric sensitivity is used for image stabilization.

This effectively corrects the blur of the photographed image when the variable power optical system vibrates.

(A-3) The second and fourth units are integrally moved during zooming.

With this, while securing a predetermined zoom ratio,
The zoom mechanism is simplified.

(A-4) The third lens unit is a third lens unit having a negative refractive power.
a lens group having a negative refractive power and a third lens group having a negative refractive power;
The parallel eccentricity sensitivities of the groups 3a and 3b are respectively represented by TSa,
When TSb is satisfied, | TSa | <| TSb | (4) is satisfied, and anti-vibration is performed in the third group b.

(A-5) The third lens unit is converted to a third lens having a negative refractive power.
a lens group having a negative refractive power and a third lens group having a negative refractive power;
The parallel eccentricity sensitivities of the groups 3a and 3b are respectively represented by TSa,
When TSb is satisfied, | TSb | <| TSa | (5) is satisfied, and anti-vibration is performed by the third lens unit.

In order to reduce the size of the drive mechanism for the image stabilizing movable lens group (anti-vibration lens group) and to reduce energy consumption, the anti-vibration lens group has a high parallel eccentric sensitivity. It is necessary that the lens weight is light.

Here, the parallel eccentric sensitivity is the ratio of the amount of movement of the image point on the image plane to the amount of movement of the lens group in the direction perpendicular to the optical axis.

Generally, the parallel eccentricity sensitivity TSi of the i-th group
Is calculated as TSi = (1−βi) βi + 1... Βn, where βi is the magnification of each lens group.

In the present invention, a lens group satisfying the conditional expression (4) or (5) is defined as an anti-vibration lens group, that is, a lens group having high parallel decentering sensitivity is defined as an anti-vibration lens group. Have gone to.

(A-6) The third group and the third group have the same spherical aberration coefficient sign.

In the present invention, the third lens unit is divided into a third lens unit having a negative refractive power and a third lens unit having a negative refractive power. When the 3a group or the 3b group was moved in the direction perpendicular to the optical axis to prevent vibration, the entire third group was moved in the direction perpendicular to the optical axis to prevent vibration. The optical performance at the time of anti-vibration is improved as compared with when.

(A-7) In order from the object side, the first lens unit includes a negative meniscus lens having a concave surface facing the image surface, a negative lens having a concave surface facing the image surface, and a convex surface facing the object surface. The second group consists of a meniscus-shaped negative lens with a concave surface facing the image plane side, a positive lens with both lens surfaces convex, and a positive lens with a convex surface facing the object side. The third lens unit includes a third lens unit having a negative refractive power and a third lens unit having a negative refractive power. The third lens unit includes a meniscus negative lens having a concave surface facing the object side, or a positive lens and a negative lens. The third group includes a negative cemented lens in which a positive lens and a negative lens are cemented, and the fourth group includes a positive lens having a convex surface facing the image surface side. The lens surface consists of a convex positive lens and a negative lens. .

An anti-vibration function in which the amount of eccentricity generated when the lens group is decentered is reduced and the eccentric aberration is satisfactorily corrected, while reducing the overall size, simplifying the mechanism, and reducing the load on the driving means. Is achieved.

(A-8) The parallel eccentric sensitivity at the telephoto end of the lens unit SL is TS, the focal length of the i-th unit is fi, and the focal lengths of the entire system at the wide-angle end and the telephoto end are fW and fT, respectively. The F number at the telephoto end of the entire system is FNot, and the distance between the first and second groups and the distance between the second and third groups during zooming from the wide-angle end to the telephoto end are respectively Δ12, Δ23,
When the size of the effective screen is φ 0.5 <φ × | TS | / fT (6)

[0041]

(Equation 2) 1.3 <f2 · FNot / fT <3 (8) 1.2 <| f3 | / f2 <2 (9) 1.1 <f4 / f2 <4 (10) 0 .15 <| Δ23 / Δ12 | <0.55 (11)

Conditional expression (6) defines the magnitude of the absolute value of the parallel eccentric sensitivity described above. If the parallel eccentric sensitivity of the image stabilizing lens unit becomes smaller than the lower limit value, the condition for image stabilization is obtained. Is undesirably large. In order to reduce the weight of the image stabilizing unit, the aperture stop is preferably fixed in a direction perpendicular to the optical axis during image stabilization.

Conditional Expressions (7) and (8) are for a zoom lens having four lens units of negative, positive, negative, and positive refractive powers, while achieving desired specifications and miniaturizing the entire lens system. While satisfying good optical performance.

If the negative refractive power of the first lens unit is increased beyond the lower limit value of the conditional expression (7), it becomes difficult to achieve satisfactory aberration correction.
Also, when the negative refractive power of the first group is weakened beyond the upper limit,
The lens system is undesirably large. If the positive refractive power of the second lens unit is increased beyond the lower limit value of conditional expression (8), it is preferable to shorten the overall length of the lens. Becomes difficult,
On the other hand, if the value exceeds the upper limit, the entire length of the lens is undesirably increased.

Conditional expressions (9) and (10) define the ratios of the focal lengths of the third and fourth lens units to the focal length of the second lens unit, respectively. In the present invention, the first group forms a front group having a negative refractive power, and the second group, the third group, and the fourth group form a rear group having a positive refractive power. By changing the distance at the time of zooming as in (3), the position of the front principal point of the entire rear unit is set so that the telephoto end is closer to the object side than the wide-angle end. It is configured to increase the zooming effect. Therefore, if the refractive powers of the third and fourth units are increased beyond the lower limits of the conditional expressions (9) and (10), it is advantageous for downsizing of the lens system, but various aberrations generated in the lens unit are large. It becomes difficult to correct this with a good balance with other lens groups, and if the refractive power is weakened beyond the upper limit, the lens system becomes large. When the magnification is changed from the wide-angle end to the telephoto end beyond the lower limit value of the conditional expression (11), the distance between the second and third lens groups is smaller than the distance between the first and second lens groups. When the size becomes smaller, the zoom lens becomes closer to a two-group zoom lens having negative and positive refractive powers, and the effect of increasing the number of groups to make the lens system more compact becomes smaller.
When the value exceeds the upper limit, the outer diameter of the lens of the fourth group is undesirably large.

Next, numerical examples of the present invention will be described. In the numerical examples, Ri is the radius of curvature of the i-th lens surface in order from the object side, Di is the i-th lens thickness and air spacing from the object side, and Ni and νi are the i-th lens surfaces in order from the object side. The refractive index and Abbe number of glass.

Table 1 shows the relationship between the above-described conditional expressions and various numerical values in the numerical examples. Numerical example 1 f = 29.7 to 82.0 FNo = 1: 3.8 to 5.9 2ω = 72.1 ° to 29.6 ° r 1 = 49.437 d 1 = 1.70 n 1 = 1.88300 ν 1 = 40.8 r 2 = 24.108 d 2 = 6.12 r 3 = 229.380 d 3 = 1.60 n 2 = 1.77250 ν 2 = 49.6 r 4 = 32.559 d 4 = 2.00 r 5 = 29.291 d 5 = 3.30 n 3 = 1.84666 ν 3 = 23.8 r 6 = 57.493 d 6 = Variable r 7 = 34.744 d 7 = 1.10 n 4 = 1.84666 ν 4 = 23.8 r 8 = 16.751 d 8 = 4.20 n 5 = 1.65844 ν 5 = 50.9 r 9 = -775.560 d 9 = 0.12 r10 = 35.455 d10 = 2.60 n 6 = 1.62230 ν 6 = 53.2 r11 = -131.727 d11 = Variable r12 = Aperture d12 = 1.20 r13 = -68.858 d13 = 1.20 n 7 = 1.69680 ν 7 = 55.5 r14 = -177.646 d14 = Variable r15 = -56.646 d15 = 2.60 n 8 = 1.74077 ν 8 = 27.8 r16 = -14.714 d16 = 1.00 n 9 = 1.67000 ν 9 = 51.6 r17 = 50.310 d17 = Variable r18 = 838.252 d18 = 3.50 n10 = 1.53113 ν10 = 62.5 r19 = -26.182 d19 = 0.15 r20 = 70.444 d20 = 3.20 n11 = 1.81554 ν11 = 44.4 r21 = -50.796 d21 = 2.00 r22 = -26.355 d22 = 1.40 n12 = 1.80518 ν12 = 25.4 r23 = 185.868 d23 = variable r24 = ∞ Focal length 29.73 49.22 81.95 Variable interval d 6 38.05 15.65 2.82 d 11 2.00 4.37 7.93 d 14 4.04 4.63 5.51 d 17 10.47 7.51 3. 07 d 23 0.00 12.16 30.41 Numerical example 2 f = 29.7 to 80.5 FNo = 1: 4.1 to 5.9 2ω = 72.1 ° to 30.1 ° r 1 = 57.062 d 1 = 1.70 n 1 = 1.88300 ν 1 = 40.8 r 2 = 30.101 d 2 = 4.98 r 3 = 347.672 d 3 = 1.60 n 2 = 1.77250 ν 2 = 49.6 r 4 = 31.249 d 4 = 2.00 r 5 = 2 9.480 d 5 = 3.30 n 3 = 1.84666 ν 3 = 23.8 r 6 = 50.850 d 6 = Variable r 7 = 39.842 d 7 = 1.10 n 4 = 1.84666 ν 4 = 23.8 r 8 = 18.412 d 8 = 3.90 n 5 = 1.65844 ν 5 = 50.9 r 9 = -105.529 d 9 = 0.12 r10 = 33.533 d10 = 2.40 n 6 = 1.62230 ν 6 = 53.2 r11 = -1328.094 d11 = Variable r12 = Aperture d12 = 1.20 r13 = -59.951 d13 = 1.20 n 7 = 1.69680 ν 7 = 55.5 r14 = -67.511 d14 = Variable r15 = -59.040 d15 = 2.20 n 8 = 1.74077 ν 8 = 27.8 r16 = -16.515 d16 = 1.00 n 9 = 1.67000 ν 9 = 51.6 r17 = 40.150 d17 = variable r18 = -185.936 d18 = 3.80 n10 = 1.53113 ν10 = 62.5 r19 = -24.705 d19 = 0.12 r20 = 70.440 d20 = 3.60 n11 = 1.81554 ν11 = 44.4 r21 = -60.474 d21 = 2.00 r22 = -29.282 d22 = 1.40 n12 = 1.80518 ν12 = 25.4 r23 = 393.843 d23 = variable r24 = 焦点 Focal length 29.75 48.86 80.51 Variable interval d 6 37.56 14.18 0.84 d 11 2.00 8.01 17.02 d 14 1.42 1.42 1.42 d 17 17.76 11.75 2.74 d 23 0.00 6.01 15.02 Numerical example 3 f = 29.3 to 81.8 FNo = 1: 4.1 to 5.9 2ω = 73.0 ° to 29.6 r 1 = 56.005 d 1 = 1.70 n 1 = 1.88300 ν 1 = 40.8 r 2 = 27.169 d 2 = 5.91 r 3 = 1377.209 d 3 = 1.60 n 2 = 1.77250 ν 2 = 49.6 r 4 = 35.209 d 4 = 0.99 r 5 = 31.032 d 5 = 3.30 n 3 = 1.84666 ν 3 = 23.8 r 6 = 63.597 d 6 = Variable r 7 = 44.337 d 7 = 1.10 n 4 = 1.84666 ν 4 = 23.8 r 8 = 19.495 d 8 = 3.60 n 5 = 1.65844 ν 5 = 50.9 r 9 = -157.570 d 9 = 0.12 r10 = 34.770 d10 = 2.20 n 6 = 1.62230 ν 6 = 53.2 r11 = -178.779 d11 = Variable r12 = Aperture d12 = 1.20 r13 = -52.178 d13 = 1.20 n 7 = 1.69680 ν 7 = 55.5 r14 = -58.774 d14 = Variable r15 = -51.428 d15 = 2.10 n 8 = 1.74077 ν 8 = 27.8 r16 = -15.987 d16 = 1.00 n 9 = 1.67000 ν 9 = 51.6 r17 = 44.862 d17 = Variable r18 = 228.604 d18 = 4.60 n10 = 1.58913 ν10 = 61.2 r19 = -28.140 d19 = 0.12 r20 = 81.167 d20 = 3.40 n11 = 1.81554 ν11 = 44.4 r21 = -74.381 d21 = 2.00 r22 = -30.533 d22 = 1.40 n12 = 1.80518 ν12 = 25.4 r23 = 327.366 d23 = Variable r24 = ∞ Focal length 29.26 49.01 81.75 Variable interval d 6 37.81 14.16 1.13 d 11 2.00 9 .02 19.54 d 14 2.82 2 .82 2.82 d 17 18.22 12.38 3.62 d 23 0.00 5.84 14.60 Numerical example 4 f = 29.3 to 81.9 FNo = 1: 3.8 to 5.9 2ω = 72.8 ° to 29.6 ° r 1 = 49.191 d 1 = 1.70 n 1 = 1.88300 ν 1 = 40.8 r 2 = 23.364 d 2 = 6.39 r 3 = 267.493 d 3 = 1.60 n 2 = 1.77250 ν2 = 49.6 r 4 = 33.209 d 4 = 1.40 r 5 = 28.731 d 5 = 3.50 n 3 = 1.84666 ν 3 = 23.8 r 6 = 58.081 d 6 = Variable r 7 = 34.385 d 7 = 1.10 n 4 = 1.84666 ν 4 = 23.8 r 8 = 16.757 d 8 = 4.20 n 5 = 1.65844 ν 5 = 50.9 r 9 =- 793.698 d 9 = 0.12 r10 = 34.653 d10 = 2.60 n 6 = 1.62230 ν 6 = 53.2 r11 = -166.093 d11 = Variable r12 = Aperture d12 = 1.00 r13 = -75.178 d13 = 1.20 n 7 = 1.69680 ν 7 = 55.5 r14 =- 184.322 d14 = Variable r15 = -58.080 d15 = 2.60 n 8 = 1.74077 ν 8 = 27.8 r16 = -14.553 d16 = 1.00 n 9 = 1.67000 ν 9 = 51.6 r17 = 47.537 d17 = Variable r18 = 929.237 d18 = 3.20 n10 = 1.53113 ν10 = 62.5 r19 = -26.715 d19 = 0.15 r20 = 67.346 d20 = 3.20 n11 = 1.81554 ν11 = 44.4 r21 = -45.599 d21 = 1.70 r22 = -26.081 d22 = 1.20 n12 = 1.80518 ν12 = 25.4 r23 = 161.558 d23 = Variable r24 = ∞ Focal length 29.35 48.93 81.94 Variable spacing d 6 37.49 15.51 3.11 d11 2.00 4.98 9.46 d14 4.72 4.72 4.72 d17 9.75 6.77 2.29 d23 0.00 12.34 30.85 Numerical example 5 f = 29.1 ~ 82.0 FNo = 1: 4.1 ~ 5.9 2ω = 73.3 ° ~ 29.6 ° r 1 = 45.588 d 1 = 1.70 n 1 = 1.88300 ν 1 = 40.8 r 2 = 22.345 d 2 = 7.04 r 3 = -4405.288 d 3 = 1.60 n 2 = 1.69819 ν2 = 55.7 r 4 = 35.358 d 4 = 0.86 r 5 = 28.851 d 5 = 3.28 n 3 = 1.84666 ν 3 = 23.8 r 6 = 56.419 d 6 = Variable r 7 = 31.152 d 7 = 1.10 n 4 = 1.84666 ν 4 = 23.8 r 8 = 17.273 d 8 = 4.50 n 5 = 1.62280 ν 5 = 57.0 r 9 = -74.682 d 9 = 0.12 r10 = 31.080 d10 = 2.30 n 6 = 1.55963 ν 6 = 61.2 r11 = 245.938 d11 = Variable r12 = Aperture d12 = 1.20 r13 = -53.021 d13 = 2.20 n 7 = 1.80610 ν 7 = 40.9 r14 = -15.900 d14 = 1.00 n 8 = 1.71300 ν 8 = 53.9 r15 = 52.574 d15 = Variable r16 = 787.123 d16 = 3.89 n 9 = 1.58267 ν 9 = 46.4 r17 = -10.548 d17 = 0.90 n10 = 1.60311 ν10 = 60.6 r18 = 185.931 d18 = Variable r19 = 697.474 d19 = 3.30 n11 = 1.60311 ν11 = 60.6 r20 = -26.991 d20 = 0.12 r21 = 62.582 d21 = 3.00 n12 = 1.78590 ν12 = 44.2 r22 = -56.600 d22 = 1.70 r23 = -27.251 d23 = 1.20 n13 = 1.72825 ν13 = 28.5 r24 = 69.030 d24 = variable r25 = ∞ focal length 29.08 48.67 81.96 variable distance d 6 36.02 13.84 1.26 d 11 2.00 6.09 12.21 d 15 1.37 1.52 1.75 d 18 12.37 8.13 1.77 d 24 0.00 9.69 24.23 Numerical example 6 f = 29.3 to 81.5 FNo = 1 : 4.1 to 5.9 2ω = 72.9 ° to 29.7 ° r 1 = 46.788 d 1 = 1.70 n 1 = 1.88300 ν 1 = 40.8 r 2 = 22.713 d 2 = 7.07 r 3 = -986.969 d 3 = 1.60 n 2 = 1.69819 ν2 = 55.7 r 4 = 36.350 d 4 = 0.98 r 5 = 29.696 d 5 = 3.18 n 3 = 1.84666 ν 3 = 23.8 r 6 = 57.986 d 6 = Variable r 7 = 32.266 d 7 = 1.10 n 4 = 1.84666 ν 4 = 23.8 r 8 = 17.705 d 8 = 4.50 n 5 = 1.62280 ν 5 = 57.0 r 9 = -67.077 d 9 = 0.12 r10 = 30.777 d10 = 2.30 n 6 = 1.55963 ν 6 = 61.2 r11 = 185.020 d11 = Variable r12 = -52.632 d12 = 2.20 n 7 = 1.80610 ν 7 = 40.9 r13 = -16.371 d13 = 1.00 n 8 = 1.71300 ν 8 = 53.9 r14 = 55.537 d14 = Variable r15 = Aperture d15 = 1.50 r16 = 75.396 d16 = 4.11 n 9 = 1.58267 ν 9 = 46.4 r17 = -11.812 d17 = 0.90 n10 = 1.60311 ν10 = 60.6 r18 = 71.039 d18 = Variable r19 = -867.782 d19 = 3.30 n11 = 1.60311 ν11 = 60.6 r20 = -28.083 d20 = 0.12 r21 = 54.314 d21 = 3.00 n12 = 1.78590 ν12 = 44.2 r22 = -53.588 d22 = 1.70 r23 = -28.017 d23 = 1.20 n13 = 1.72825 ν13 = 28.5 r24 = 53.239 d24 = Variable r25 = 焦点 Focal length 29.32 48.74 81.50 Variable interval d 6 35.40 13.69 1.20 d 11 2.00 6.43 13.08 d 14 0.93 0.93 0.93 d 18 12.73 8.30 1.65 d 24 -0.06 9.26 23.24 Numerical example 7 f = 29.7 to 80.9 FNo = 1: 4.1 to 5.9 2ω = 72.2 ° to 30.0 ° r 1 = 64.981 d 1 = 1.70 n 1 = 1.88300 ν 1 = 40.8 r 2 = 24.248 d 2 = 6.38 r 3 = -328.420 d 3 = 1.60 n 2 = 1.69819 ν2 = 55.7 r 4 = 46.286 d 4 = -0.14 r 5 = 31.889 d 5 = 3.42 n 3 = 1.84666 ν 3 = 23.8 r 6 = 76.947 d 6 = variable r 7 = 39.392 d 7 = 1.10 n 4 = 1.84666 ν 4 = 23.8 r 8 = 19.702 d 8 = 4.00 n 5 = 1.62280 ν 5 = 57.0 r 9 = -67.926 d 9 = 0.12 r10 = 29.275 d10 = 2.20 n 6 = 1.55963 ν 6 = 61.2 r11 = 295.264 d11 = Variable r12 = Aperture d12 = 1.20 r13 = -56.618 d13 = 2.20 n 7 = 1.80610 ν 7 = 40.9 r14 = -17.247 d14 = 1.00 n 8 = 1.71300 ν 8 = 53.9 r15 = 46.076 d15 = Variable r16 = 76.588 d16 = 3.76 n 9 = 1.58267 ν 9 = 46.4 r17 = -11.888 d17 = 0.90 n10 = 1.60311 ν10 = 60.6 r18 = 71.360 d18 = Variable r19 = 141.854 d19 = 4.20 n11 = 1.65160 ν11 = 58.5 r20 = -27. 702 d20 = 0.12 r21 = 57.101 d21 = 3.00 n12 = 1.78590 ν12 = 44.2 r22 = -130.566 d22 = 2.20 r23 = -29.600 d23 = 1.20 n13 = 1.72825 ν13 = 28.5 r24 = 66.685 d24 = Variable r25 = 焦点 Focal length 29.69 48.79 80.87 Variable interval d 6 36.27 13.89 1.01 d 11 2.00 7.93 16.83 d 15 1.61 1.61 1.61 d 18 16.37 10.44 1.54 d 24 2.00 7.93 16.83

[0048]

[Table 1]

[0049]

As described above, according to the present invention, by moving the relatively small and light lens group constituting a part of the variable power optical system in the direction perpendicular to the optical axis, the variable power optical system is vibrated. When correcting image blurring caused by (tilting), by appropriately configuring the lens configuration of each lens group, it is possible to reduce the size of the entire apparatus,
While simplifying the mechanism and reducing the load on the driving means, the amount of eccentricity generated when the lens group is decentered is suppressed to a small value, and the eccentric aberration is satisfactorily corrected. A variable power optical system having an anti-vibration function with a magnification ratio of about 3 can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a lens at a wide-angle end according to Numerical Embodiment 1 of the present invention.

FIG. 2 is a sectional view of a lens at a wide-angle end according to a second numerical embodiment of the present invention.

FIG. 3 is a sectional view of a lens at a wide angle end according to Numerical Embodiment 3 of the present invention.

FIG. 4 is a sectional view of a lens at a wide angle end according to Numerical Example 4 of the present invention.

FIG. 5 is a sectional view of a lens at a wide angle end according to Numerical Example 5 of the present invention.

FIG. 6 is a lens cross-sectional view at a wide angle end according to Numerical Example 6 of the present invention.

FIG. 7 is a sectional view of a lens at a wide-angle end according to a seventh embodiment of the present invention.

FIGS. 8A and 8B are aberration charts of Numerical Embodiments 1 (A) and 1 (B) for an object at infinity at the wide-angle end and for vibration proof when tilted by 0.5 °. FIGS.

FIG. 9 is a diagram illustrating aberrations of a numerical example 1 of the present invention (A) and (B) when the object is at infinity at the telephoto end and at the time of image stabilization when the object is tilted by 0.5 °.

10A and 10B are aberration diagrams of a numerical example 2 (A) and (B) of an object at infinity at the wide-angle end and a standard image at the time of image stabilization at an angle of 0.5 °.

11A and 11B are aberration diagrams of a numerical example 2 of the present invention (A) and (B) for an object at infinity at the telephoto end, and aberrations at the time of tilting by 0.5 °.

12A and 12B are aberration diagrams of a numerical example 3 (A) and (B) when the object is at infinity at the wide angle end and when the image is tilted by 0.5 ° and at the time of image stabilization.

FIG. 13 is a diagram illustrating aberrations of a numerical example 3 of the present invention (A) and (B) when the object is at infinity at the telephoto end and when vibration is reduced by 0.5 °.

FIGS. 14A and 14B are aberration charts of a numerical example 4 (A) and (B) for an object at infinity at the wide-angle end and a vibration compensation when tilted by 0.5 °;

15A and 15B are aberration diagrams of a numerical example 4 of the present invention (A) and (B) for an object at infinity at the telephoto end and for vibration proof when tilted by 0.5 °;

16A and 16B are aberration charts of Numerical Embodiment 5 (A) and (B) for an object at infinity at the wide-angle end and for vibration proof when tilted by 0.5 °;

17A and 17B are aberration diagrams of a numerical example 5 of the present invention (A) and (B) for an object at infinity at the telephoto end, and aberrations at the time of tilting by 0.5 °.

18A and 18B are aberration diagrams of a numerical example 6 (A) and a numerical example 6 (B) of an object at infinity at the wide-angle end and an image of vibration reduction at an angle of 0.5 °.

19A and 19B are aberration diagrams of a numerical example 6 of the present invention (A) and (B) for an object at infinity at the telephoto end, and aberrations at the time of tilting by 0.5 °.

20A and 20B are aberration diagrams of a numerical example 7 (A) and (B) for an object at infinity at the wide-angle end and a standard image at the time of tilting by 0.5 °.

21A and 21B are aberration diagrams of a numerical example 7 of the present invention (A) and (B) for an object at infinity at the telephoto end, and an image at the time of image stabilization at a tilt of 0.5 °.

[Explanation of Signs] L1 First group L2 Second group L3 Third group L3a Third group L3b Third group L4 Fourth group SL Vibration-proof lens group SP diaphragm d d-line g g-line ΔM Meridional image plane ΔS Sagittal image plane

Claims (12)

[Claims] 1. A first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a fourth lens unit having a positive refractive power. The third unit is composed of a plurality of lens units, and some of the lens units SL are moved in a direction perpendicular to the optical axis to perform the magnification change. D1W> D1T D2W <D2T D3W> D3T When the distance between the i-th lens unit and the (i + 1) -th lens unit at the wide-angle end and the telephoto end is Di, the camera shake is corrected when the optical system vibrates. A variable power optical system having an anti-shake function. 2. The image stabilizing function according to claim 1, wherein a fixed stop is provided at the time of image stabilization on the object side, image surface side, or lens system of said third group. Variable power optical system. 3. The third lens unit comprises two lens units, a third lens unit having a negative refractive power and a third lens unit having a negative refractive power, wherein the lens having the larger absolute value of the parallel decentering sensitivity is used. 2. A variable power optical system having an image stabilizing function according to claim 1, wherein image stabilization is performed in groups. 4. The variable power optical system according to claim 1, wherein the lens interval of the plurality of lens units of the third group is constant during zooming. 5. The variable power optical system according to claim 1, wherein the second unit and the fourth unit are moved integrally during zooming. 6. The variable power optical system according to claim 1, wherein the third unit is fixed at the time of zooming. 7. The third lens unit includes two lens units, a third lens unit having a negative refractive power and a third lens unit having a negative refractive power.
2. The anti-vibration method according to claim 1, wherein | TSa | <| TSb | is satisfied when the parallel eccentric sensitivity of the lens group and the third lens group is TSa and TSb, respectively, and the third lens group performs vibration isolation. Variable magnification optical system with functions. 8. The third lens unit includes two lens units, a third lens unit having a negative refractive power and a third lens unit having a negative refractive power.
2. The anti-vibration method according to claim 1, wherein | TSb | <| TSa | is satisfied when the parallel eccentricity sensitivity of the lens group and the third lens group is TSa and TSb, respectively. Variable magnification optical system with functions. 9. A variable-power optical system having a vibration-proof function according to claim 7, wherein the sign of the spherical aberration coefficient of said third lens group is equal to that of said third lens group. 10. The first lens unit includes, in order from the object side, a negative meniscus lens having a concave surface facing the image surface side, a negative lens having a concave surface facing the image surface side, and a meniscus shape having a concave surface facing the object side. The second group includes a meniscus negative lens having a concave surface facing the image surface side, a positive lens having both lens surfaces convex, and a positive lens having a convex surface facing the object side. The group includes a third lens unit having a negative refractive power and a third lens unit having a negative refractive power. The third lens unit is a meniscus negative lens having a concave surface facing the object side, or a negative lens having a positive lens and a negative lens cemented. The third group includes a negative cemented lens in which a positive lens and a negative lens are joined, and the fourth lens group includes a positive lens having a convex surface facing the image surface side and both lens surfaces. It consists of a convex positive lens and a negative lens A variable power optical system having the image stabilizing function according to claim 1. 11. The parallel eccentric sensitivity at the telephoto end of the lens unit SL is TS, the focal length of the i-th unit is fi, and the focal lengths at the wide-angle end and the telephoto end of the entire system are fW and fT, respectively. The F-number at the telephoto end is FNot, the amount of change in the distance between the first and second units during zooming from the wide-angle end to the telephoto end and the second
When the distance between the group and the third group is Δ12 and Δ23, respectively, and the dimension of the effective screen is φ: 0.5 <φ × | TS | / fT 1.3 <f2 · FNot / fT <3 1.2 <| f3 | / f2 <2 1.1 <f4 / f2 <4 0.15 <| Δ23 / Δ12 | <0.55 2. The variable power optical system according to claim 1, wherein the variable power optical system has an image stabilizing function. 12. The device according to claim 1, wherein the first group forms a front group having a negative refractive power, and the second, third, and fourth groups form a rear group having a positive refractive power. Item 12. A variable power optical system having the image stabilizing function according to any one of Items 1 to 11.