JP2013054269A - Optical system and imaging apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical system that can easily obtain a high quality image in the entire image area despite a wide angle of view and can maintain satisfactory optical performance even in preventing vibration.SOLUTION: In an optical system in which a focal distance is shorter than a back focus and lens groups are arranged on an object side and an image side with respect to an aperture stop SP, a vibration-proof lens group Gis is arranged at a position adjacent to the image side of the aperture stop, the vibration-proof lens group Gis moving in a direction including a component in a vertical direction with respect to an optical axis, thereby moving an image position. The optical system appropriately sets the focal distance f of the entire system, the focal distance fis of the vibration-proof lens group, a distance Dis on the optical axis from the aperture stop to the aperture stop side lens face of the vibration-proof lens group, a distance DL on the optical axis from a first lens face on the object side in the infinity of the distance of the object, and Don the optical axis from the aperture stop to a final lens face.

Description

  The present invention relates to an optical system, and is suitable for, for example, a photographing optical system used in an imaging apparatus such as a silver salt film camera, a digital still camera, a video camera, a digital video camera, and a TV camera.

  In recent years, image pickup elements used in image pickup apparatuses such as digital cameras and video cameras have been increased in the number of pixels (higher density). The photographic lens used in an image pickup apparatus having such a high-pixel image pickup device has various aberrations corrected well, high optical performance, little shading (insufficient light quantity), and good telecentric characteristics. It is requested. In addition, it is required to be a retrofocus type wide-angle shooting lens that allows easy shooting with a wide field of view.

  In addition, in order to obtain a higher-definition image, it is required to have a function of suppressing image degradation due to the influence of vibration such as camera shake during photographing, a so-called vibration-proof mechanism. As an anti-vibration mechanism, there is known a method of correcting a change in image position caused by camera shake or the like by moving a part of a lens group of an optical system in a direction including a component perpendicular to the optical axis. . This anti-vibration mechanism is often used especially for a photographing lens including a telephoto range in which image deterioration due to camera shake or the like appears remarkably.

  On the other hand, a so-called retrofocus type wide-angle lens whose focal length is shorter than the back focus is known as a wide-angle lens that corrects image position fluctuations caused by camera shake or the like by using an anti-vibration mechanism. (Patent Document 1). Patent Document 1 discloses a wide-angle lens including a lens group GF having a negative refractive power and a lens group GL having a positive refractive power in order from the object side. It discloses that the two image-side positive lenses constituting the lens group GL are rotationally moved around a point on the optical axis to perform image stabilization.

JP-A-8-220427

  In a retrofocus imaging optical system, a lens unit with negative refractive power is arranged in front of the aperture stop, and a lens group with positive refractive power is arranged behind the aperture stop, ensuring a long back focus. It facilitates wide-angle shooting. Even in a wide-angle shooting optical system, image blurring occurs when the shooting optical system vibrates. For this reason, it is effective to use the image stabilization function in order to obtain a good image even with a wide-angle imaging optical system.

  In order to correct image blur when the optical system (shooting optical system) vibrates with an anti-vibration function, it is not simply provided with an anti-vibration function in the optical path, but is placed at an appropriate position in the photographic optical system. Is important for obtaining good optical performance in image stabilization. In Patent Document 1, two lenses arranged at a position closest to the image plane side are used as an anti-vibration lens group. For this reason, the incident position of the principal ray of the off-axis light beam incident on the vibration proof lens is increased, the lens diameter is increased, and aberration correction at the time of vibration proof tends to be difficult.

  On the other hand, if a lens arranged closer to the object side than the aperture stop is used as an anti-vibration lens group, the distance between the position of the exit pupil and the image plane tends to be narrowed, and the light incident angle on the image plane is increased. When the angle of incidence of light on the image plane is large, the effect of the microlens array placed immediately before each light receiving element is affected, so that the light flux that should reach the periphery of the screen is less likely to reach the light receiving element and shading occurs. Come on.

  To correct image blurring when the optical system vibrates using the image stabilization function while maintaining good optical performance, the lens configuration of the image stabilization lens group and the optical system in which the image stabilization lens group is arranged can be corrected. It is important to set the position etc. appropriately. This is particularly important in a wide-angle shooting optical system for obtaining high optical performance over the entire screen while widening the angle of view. If these elements are inappropriate, a large amount of decentration aberration occurs during image stabilization, and the optical performance is greatly deteriorated.

  An object of the present invention is to provide an optical system that can easily obtain a high-quality image over the entire screen while having a wide angle of view and that can easily maintain good optical performance even during image stabilization.

The optical system of the present invention has a focal length shorter than the back focus, and in the optical system in which the lens groups are respectively arranged on the object side and the image side with respect to the aperture stop, the light is placed at a position adjacent to the image side of the aperture stop. An anti-vibration lens group that moves the image position by moving in a direction including a component perpendicular to the axis is disposed, and the focal length of the entire system is f, the focal length of the anti-vibration lens group is fis, The distance on the optical axis from the aperture stop to the lens surface on the aperture stop side of the anti-vibration lens group is Dis, and the distance on the optical axis from the first lens surface on the object side to the final lens surface at infinity of the object distance. DL, when the distance on the optical axis from the aperture stop to the final lens surface is _DFS ,
0.1 <f / fis <1.0
0.00 <Dis / DL <0.25
0.3 _<D FS /f<2.0
It is characterized by satisfying the following conditions.

  According to the present invention, it is easy to obtain a high-quality image over the entire screen while having a wide angle of view, and an optical system that can easily maintain good optical performance even during image stabilization is obtained.

Lens sectional view of Example 1 Longitudinal aberration diagram of Example 1 (A), (B) Lateral aberration diagrams when the reference state of Example 1 of the present invention and 0.5 ° image stabilization are corrected Lens sectional view of Example 2 Longitudinal aberration diagram of Example 2 (A), (B) Lateral aberration diagrams when the reference state of Example 2 of the present invention and 0.5 ° image stabilization correction are performed Lens sectional view of Example 3 Longitudinal aberration diagram of Example 3 (A), (B) Lateral aberration diagram when the reference state of Example 3 of the present invention and the image stabilization correction of 0.5 ° are performed Lens sectional view of Example 4 Longitudinal aberration diagram of Example 4 (A), (B) Lateral aberration diagram when the reference state of Example 4 of the present invention and the image stabilization correction of 0.5 ° are performed Schematic diagram of main parts of an imaging apparatus of the present invention

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The optical system of the present invention is a retrofocus type optical system in which the focal length is shorter than the back focus and the lens groups are respectively arranged on the object side and the image side with respect to the aperture stop.

  For example, the combined refractive power of the front lens unit LF closer to the object side than the aperture stop is negative, and the combined refractive power of the rear lens unit LR closer to the image side than the aperture stop is positive. An anti-vibration lens group is arranged at a position adjacent to the image side of the aperture stop and is made of a single lens or a cemented lens and moves in a direction including a component perpendicular to the optical axis to move the image position. .

  FIG. 1 is a lens cross-sectional view of a first embodiment of the present invention, and FIG. 2 is a longitudinal aberration diagram of the first embodiment. FIGS. 3A and 3B are lateral aberration diagrams when the reference state and the image stabilization correction of 0.5 ° are performed in Example 1 of the present invention. 4 is a lens cross-sectional view of the second embodiment of the present invention, and FIG. 5 is a longitudinal aberration diagram of the second embodiment. 6A and 6B are lateral aberration diagrams when the reference state and the image stabilization correction of 0.5 ° in Example 2 of the present invention are performed.

  7 is a lens cross-sectional view of Example 3 of the present invention, and FIG. 8 is a longitudinal aberration diagram of Example 3. As shown in FIG. FIGS. 9A and 9B are lateral aberration diagrams when the reference state and the image stabilization correction of 0.5 ° are performed in Example 3 of the present invention. 10 is a lens sectional view of Example 4 of the present invention, and FIG. 11 is a longitudinal aberration diagram of Example 4. As shown in FIG. FIGS. 12A and 12B are lateral aberration diagrams when the reference state and the image stabilization correction of 0.5 ° are performed in Example 4 of the present invention. FIG. 13 is a schematic diagram of a main part of a single-lens reflex camera (imaging device) including the optical system of the present invention.

  The optical system of each embodiment is a photographing optical system used for an imaging apparatus (optical apparatus) such as a digital still camera, a video camera, and a silver salt film camera. In the lens cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). In addition, you may use the optical system of each Example as projection lenses, such as a projector. At this time, the left side is the screen and the right side is the projected image.

  In the lens cross-sectional view, LA is an optical system. The optical system LA has a front lens unit LF having a negative refractive power on the object side and a rear lens unit LR having a positive refractive power on the image side with the aperture stop SP interposed therebetween. L1 is a first lens unit having a negative refractive power that does not move during focusing, and L2 is a second lens unit that moves during focusing.

  The second lens unit L2 includes lens units L2a and L2b on the object side and the image side of the aperture stop (stop) SP, respectively. A vibration-proof lens group Gis made of a single lens or a cemented lens is provided at a position adjacent to the image side of the aperture stop SP. FS is a fixed aperture whose aperture diameter does not change. IP is an image plane. When the imaging optical system of a video camera or digital still camera is used, the imaging surface of a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor is a silver salt film camera. Corresponds to the film surface.

  Each longitudinal aberration diagram shows spherical aberration, astigmatism, distortion, and lateral chromatic aberration in order from the left. In the diagrams showing spherical aberration and lateral chromatic aberration, the solid line represents the d line (587.6 nm), and the broken line represents the g line (435.8 nm). In the diagram showing astigmatism, the solid line represents the sagittal direction ΔS of the d line, and the broken line represents the meridional direction ΔM of the d line. Moreover, the figure which shows distortion represents the distortion in d line | wire. In the lateral aberration diagram, the solid line represents the meridional direction ΔM of the d line, and the broken line represents the sagittal direction ΔS of the d line. Fno is the F number, ω is the half angle of view (degrees) of the shooting angle of view, and hgt is the image height.

  The optical system LA of the present invention is a so-called retro lens in which a front lens group LF having a negative refractive power is disposed on the object side of the aperture stop SP, and a rear lens group LR having a positive refractive power is disposed on the image side of the aperture stop SP. Focus type (retro focus type).

  In a retrofocus type optical system, it is easy to position the image side principal point on the image side from the final lens surface of the optical system, and the focal length of the entire system is the distance from the final lens surface of the optical system to the image surface (back Smaller than the focus). This optical system can easily widen the angle of view. In addition, this optical system is suitable for a photographic lens that requires a long back focus, such as a single-lens reflex camera in which a quick return mirror is disposed on the image plane side of the final lens.

  In the retrofocus type optical system, the effective diameter of the lens near the aperture stop is relatively small. In general, the height from the optical axis of the off-axis light beam that reaches the maximum image height on the image plane increases as the distance from the aperture stop increases (increases). In particular, the tendency becomes more remarkable in an optical system with a wide angle of view.

  In order to ensure a sufficient amount of light for off-axis rays (periphery of the screen) in such an optical system with a wide angle of view, it is desirable to avoid cutting off-axis rays as much as possible with an aperture stop that determines the open F number light flux. . For this reason, it is desirable that the aperture stop be disposed near the center in the optical axis direction of the optical system, not near the first lens surface closest to the object or the final lens surface closest to the image side in the optical system. According to this, it can be configured such that the principal ray of off-axis rays intersects the optical axis in the vicinity of the aperture stop. As a result, the lens arranged in the vicinity of the aperture stop has a relatively small effective diameter.

  In the optical system of the present invention, the lens group disposed at a position adjacent to the image side of the aperture stop is a vibration-proof lens group that moves so as to have a component in a direction perpendicular to the optical axis. This facilitates the lens holding mechanism and the drive mechanism while reducing the size of the vibration-proof lens group. Furthermore, by arranging the anti-vibration lens group in the vicinity of the stop, the height of the off-axis light beam passing through the anti-vibration lens group can be reduced. This reduces the fluctuation of the aberration around the screen during image stabilization.

  Specifically, in each embodiment, the anti-vibration lens group Gis is disposed at a position adjacent to the image side of the aperture stop SP, and the anti-vibration lens group Gis is moved so as to have a component in a direction perpendicular to the optical axis. As a result, fluctuations in the image position caused by camera shake or the like of the optical system LA are corrected (anti-vibration).

In each embodiment, the focal length of the entire system is f, and the focal length of the image stabilizing lens group Gis is fis. The distance on the optical axis from the aperture stop SP to the lens surface on the aperture stop SP side of the anti-vibration lens group Gis is Dis, and the distance on the optical axis from the first lens surface on the object side to the final lens surface at the object distance infinity. Is DL. The distance on the optical axis from the aperture stop SP to the final lens surface is _DFS .

At this time,
0.1 <f / fis <1.0 (1)
0.00 <Dis / DL <0.25 (2)
0.3 <D _FS /f<2.0 (3)
Is satisfied.

  Conditional expression (1) is for making the refractive power (reciprocal of the focal length) of the anti-vibration lens group Gis with respect to the focal length of the entire system appropriate. If the upper limit of conditional expression (1) is exceeded and the refractive power of the anti-vibration lens group Gis becomes strong, a large amount of decentration aberrations occur during anti-vibration, and the optical performance deteriorates. In addition, the amount of image position correction (anti-vibration sensitivity) with respect to the amount of movement of the anti-vibration lens group Gis increases. For this reason, the amount of movement of the image stabilizing lens group Gis for obtaining a certain image stabilizing effect becomes too small, and it becomes difficult to drive the amount of movement electrically or mechanically with high accuracy.

  Also, if the refractive power of the image stabilizing lens group Gis becomes weaker than the lower limit of the conditional expression (1), the image stabilization sensitivity becomes too low, and the amount of driving to have a vertical component with respect to the optical axis during image stabilization. Becomes larger and the drive mechanism becomes larger.

  Conditional expression (2) is for making the distance on the optical axis from the aperture stop SP to the lens surface closest to the aperture stop SP in the image stabilizing lens group Gis appropriate.

  When the image stabilizing lens group Gis is separated from the aperture stop SP and approaches the image plane side beyond the upper limit of the conditional expression (2), the image stabilizing lens group Gis becomes larger. Further, the height from the optical axis of the off-axis light beam passing through the anti-vibration lens group Gis becomes high, and it becomes difficult to correct the aberration of the off-axis light beam at the time of image stabilization. When the vibration-proof lens group Gis approaches the aperture stop SP nearing the lower limit of the conditional expression (2), the aperture stop and the vibration-proof lens group Gis are likely to interfere with each other, and it becomes difficult to control the F-number light beam.

  Conditional expression (3) defines the distance from the aperture stop SP to the final lens surface of the optical system LA. If the upper limit of conditional expression (3) is exceeded and the position of the aperture stop SP moves away from the image plane, the total lens length becomes long, and it becomes difficult to reduce the size of the optical system LA. When the lower limit of conditional expression (3) is exceeded and the position of the aperture stop SP approaches the image plane, the exit pupil position becomes close to the image plane, so that the light incident angle on the image plane increases. As a result, when a solid-state image sensor such as a CCD or CMOS is used, the amount of light on the periphery of the screen decreases. Further, since it becomes difficult to secure a telecentric optical system, a lot of shading occurs.

  In each embodiment, it is more preferable to set the numerical ranges of the conditional expressions (1) to (3) as follows.

0.11 <f / fis <0.90 (1a)
0.00 <Dis / DL <0.08 (2a)
0.4 <D _FS /f<1.8 (3a)
According to each embodiment, by specifying the lens configuration as described above, the anti-vibration lens group can be easily miniaturized and a good image can be obtained even during the image stabilization while having high optical performance. A wide field angle optical system having a vibration function can be obtained.

  In each embodiment, it is more preferable to satisfy one or more of the following conditions. Let βis be the lateral magnification of the vibration-proof lens group Gis. Let βr be the lateral magnification of the optical system arranged on the image side of the image stabilizing lens group Gis. The length of the anti-vibration lens group Gis on the optical axis is Lis. Let DL be the distance on the optical axis from the first lens surface to the last lens surface at an infinite object distance. Let TL be the distance on the optical axis from the first lens surface to the image plane (lens total length). At this time, it is preferable to satisfy one or more of the following conditional expressions.

0.1 <| (1-βis) βr | <1.3 (4)
0.01 <Lis / DL <0.15 (5)
1.0 <TL / f <4.5 (6)
Conditional expression (4) is for obtaining high optical performance while maintaining good optical performance during vibration isolation. Here, the lateral magnifications βis and βr are values in a state where the entire system is focused to an infinite object distance.

  Conditional expression (4) relates to the ratio (vibration sensitivity) between the amount of movement of the component in the direction perpendicular to the optical axis of the image stabilizing lens group Gis and the amount of image point movement on the image plane that occurs in association therewith. The larger the value of the image stabilization sensitivity, the easier the image point can be moved with a smaller amount of movement.

  If the anti-vibration sensitivity is too high exceeding the upper limit of the conditional expression (4), the moving amount of the anti-vibration lens group Gis for obtaining a certain anti-shake effect becomes too small, and the moving amount is electrically or mechanically Therefore, it becomes difficult to drive with high accuracy. In addition, when the vibration proof sensitivity is too low exceeding the lower limit value of the conditional expression (4), the amount of driving to have a component perpendicular to the optical axis at the time of vibration proof becomes large and the drive mechanism becomes large. Come.

  Conditional expression (5) is for reducing the size of the image stabilizing lens group Gis. Conditional expression (5) is an appropriate ratio of the length Lis on the optical axis of the image stabilizing lens group Gis to the distance DL on the optical axis from the first lens surface to the final lens surface of the optical system LA at an infinite object distance. Stipulated in the scope. If the length on the optical axis of the vibration-proof lens group Gis exceeds the upper limit of the conditional expression (5), the vibration-proof mechanism becomes large. If the length on the optical axis of the image stabilizing lens group Gis becomes shorter than the lower limit of the conditional expression (4), the lens shape that makes it difficult to process each lens constituting the image stabilizing lens group Gis will be obtained.

  Conditional expression (6) is for reducing the size of the entire system while maintaining good optical performance. Conditional expression (6) prescribes the ratio of a preferable total lens length (length from the first lens surface to the image plane) with respect to the focal length of the optical system LA, and the tele ratio (telephoto ratio) of the optical system. It corresponds to the degree. If the upper limit of conditional expression (6) is exceeded, it will be difficult to downsize the entire system. Conversely, if the lower limit of conditional expression (6) is exceeded, it will be difficult to achieve good optical performance while ensuring sufficient back focus. More preferably, the numerical ranges of conditional expressions (4), (5) and (6) are set as follows.

0.11 <| (1-βis) βr | <1.20 (4a)
0.015 <Lis / DL <0.100 (5a)
2.5 <TL / f <4.1 (6a)
In the first embodiment, focusing from an infinite object to a close object is performed by moving the second lens unit L2 including seven lenses including the image stabilizing lens unit Gis and the aperture stop SP to the object side. As is apparent from the respective aberration diagrams, in the first embodiment, various aberrations are well corrected including during image stabilization. The anti-vibration lens group Gis is one positive lens having a biconvex shape. The first lens unit L1 includes a negative lens and a positive lens.

  In the second embodiment, focusing from an object at infinity to an object at a close distance is performed by moving a second lens unit L2 including nine lenses including an anti-vibration lens unit Gis and an aperture stop SP to the object side. . As is apparent from the respective aberration diagrams, in the second embodiment, various aberrations are well corrected including during image stabilization.

  In the third embodiment, focusing from an object at infinity to an object at a close distance is performed by moving a second lens unit L2 including eight lenses including the anti-vibration lens unit Gis and the aperture stop SP to the object side. . As is apparent from each aberration diagram, in Example 3, various aberrations are well corrected including during image stabilization. The anti-vibration lens group Gis is a cemented lens in which a biconvex positive lens and a negative lens are cemented. The first lens unit L1 includes a negative lens and a positive lens.

  In Example 4, focusing from an object at infinity to an object at a close distance is performed by moving the second lens unit L2 including eight lenses including the image stabilizing lens unit Gis and the aperture stop SP to the object side. . As is apparent from each aberration diagram, in Example 4, various aberrations are well corrected including during image stabilization. The anti-vibration lens group Gis is a cemented lens obtained by cementing a meniscus negative lens having a convex object side surface and a biconvex positive lens. The first lens unit L1 includes a negative lens and a positive lens.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  Next, an embodiment in which the optical system of the present invention is used as an imaging optical system in a single-lens reflex camera system (imaging apparatus) (optical apparatus) will be described with reference to FIG.

  In FIG. 13, 10 is a single-lens reflex camera body, and 11 is an interchangeable lens equipped with the optical system of the present invention. Reference numeral 12 denotes a recording unit such as a film or an image sensor for recording a subject image obtained through the interchangeable lens 11. Reference numeral 13 denotes a finder optical system for observing a subject image from the interchangeable lens 11, and reference numeral 14 denotes a rotating quick return mirror for switching the subject image formed by the interchangeable lens 11 to the recording means 12 and the finder optical system 13 for transmission. is there.

  When observing the subject image with the finder optical system 13, the subject image formed on the focus plate 15 via the quick return mirror 14 is converted into an erect image with the pentaprism 16 and then magnified with the eyepiece optical system 17. . At the time of shooting, the quick return mirror 14 rotates in the direction of the arrow, and the subject image is formed and recorded on the recording means 12. Reference numeral 18 denotes a submirror, and 19 denotes a focus detection device.

  In this way, by applying the optical system of the present invention to an imaging apparatus such as an interchangeable lens such as a single-lens reflex camera, an imaging apparatus having high optical performance can be realized. The optical system of the present invention can be similarly applied to a mirrorless single-lens reflex camera without a quick return mirror.

The numerical examples 1 to 4 corresponding to the first to fourth examples are shown below. In each numerical example, i indicates the order of the surfaces from the object side, and ri is the i-th (i-th surface) radius of curvature. di is an interval between the i-th surface and the i + 1-th surface. ndi and νdi denote a refractive index and an Abbe number based on the d line, respectively. BF is a back focus. * Indicates that the surface is aspherical. Surface number 1 is a dummy surface used in the design and does not constitute a lens group.
(Aspheric data) shows the aspheric coefficient when the aspheric surface is expressed by the following equation.

x = (h ² / R) / [1+ {1− (1 + k) (h / R) ² } ^1/2 + B · h ⁴ + C · h ⁶ + D · h ⁸ + E · h ¹⁰ + F · h ¹²
However,
x: A displacement amount from the reference plane in the optical axis direction.
h: Height in the direction perpendicular to the optical axis.
R: radius of a quadric surface as a base.
B, C, D, E, and F are fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order aspheric coefficients, respectively.
In addition, the display of “e-Z” means “10 ^−Z ”. Table 1 shows the relationship between the above-described conditional expressions and numerical values in the numerical examples.

[Numerical Example 1]
Unit mm
Surface data surface number rd nd νd Effective diameter
1 ∞ 1.70 51.00
2 62.223 1.53 1.60311 60.6 42.00
3 26.747 6.75 36.15
4 277.138 2.79 1.77250 49.6 35.89
5 -158.852 7.05 35.24
6 72.398 1.13 1.48749 70.2 23.44
7 19.530 10.06 20.54
8 22.447 3.40 1.91082 35.3 13.99
9 -42.595 0.72 1.73800 32.3 13.69
10 29.265 3.28 13.24
11 (Aperture) ∞ 4.09 13.11
12 105.862 1.59 1.72916 54.7 13.50
13 -105.862 3.57 13.50
14 -13.728 1.45 1.74000 28.3 12.82
15 -251.595 4.39 1.69680 55.5 15.18
16 -18.429 0.80 17.50
17 * -64.983 3.21 1.58313 59.4 19.47
18 -19.807 0.00 20.50
19 (Flare cut diaphragm) 23.78
Image plane ∞

Aspheric data 17th surface
B = -2.52195e-005 C = 4.30341e-008 D = -6.12181e-010 E = 1.94445e-012
F = 0.00000e + 000

Various data focal length 28.60
Gis focal length 72.82
F number 2.86
Angle of view 37.11
Statue height 21.64
Total lens length 95.79
BF 38.28

[Numerical Example 2]
Unit mm
Surface data surface number rd nd νd
1 ∞ 1.70
2 60.045 1.60 1.71300 53.9
3 24.527 6.80
4 210.703 3.00 1.80610 33.3
5 -149.670 7.01
6 36.681 1.00 1.77250 49.6
7 14.802 3.43
8 -534.728 3.65 1.56732 42.8
9 -35.638 1.63
10 -26.187 0.80 1.77250 49.6
11 137.833 0.42
12 24.165 4.25 1.91082 35.3
13 -20.084 4.38 1.84666 23.9
14 -63.845 2.70
15 (Aperture) ∞ 3.01
16 106.389 1.50 1.72916 54.7
17 -152.064 5.06
18 -11.257 1.35 1.75520 27.5
19 -42.148 3.65 1.59522 67.7
20 -14.866 0.56
21 * -61.679 3.98 1.58313 59.4
22 -17.579 0.00
23 (Flare cut diaphragm)
Image plane ∞

Aspheric data 21st surface
B = -3.22021e-005 C = -2.92301e-008 D = 4.16067e-010 E = -5.09494e-012
F = 1.35149e-014

Focal length 24.60
Gis Focal Length 86.06
F number 2.91
Angle of View 41.33
Statue height 21.64
Total lens length 99.76
BF 38.28

[Numerical Example 3]
Unit mm
Surface data surface number rd nd νd
1 ∞ 1.50
2 63.920 1.80 1.60311 60.6
3 29.247 5.41
4 136.457 3.25 1.77250 49.6
5 -462.325 5.83
6 37.049 1.30 1.48749 70.2
7 13.091 11.42
8 24.977 7.57 1.91082 35.3
9 -14.684 0.80 1.83400 37.2
10 29.879 1.56
11 (Aperture) ∞ 1.20
12 75.785 3.40 1.72916 54.7
13 -12.701 0.80 1.85026 32.3
14 -31.939 0.76
15 -17.094 0.80 1.67270 32.1
16 306.563 0.76
17 -43.846 2.46 1.77250 49.6
18 -17.774 0.80
19 * -54.483 2.51 1.58313 59.4
20 -20.711 0.00
21 (Flare cut diaphragm)
Image plane ∞


Aspheric data 19th surface
B = -1.66198e-005 C = 3.23707e-008 D = -4.23969e-010 E = 0.00000e + 000
F = 0.00000e + 000

Focal length 28.61
Gis focal length 37.91
F number 2.86
Angle of view 37.10
Statue height 21.64
Total lens length 93.63
BF 37.73

[Numerical Example 4]
Unit mm
Surface data surface number rd nd νd
1 ∞ 1.50
2 69.324 2.00 1.51633 64.1
3 28.413 4.78
4 84.432 3.29 1.74 100 52.6
5 9159.727 5.53
6 42.985 1.30 1.58913 61.1
7 15.781 12.47
8 21.537 4.95 1.83400 37.2
9 -26.310 0.85 1.72342 38.0
10 27.885 2.38
11 (Aperture) ∞ 1.21
12 72.560 0.80 1.72000 46.0
13 14.632 2.77 1.69 100 54.8
14 -97.123 3.88
15 -12.936 0.80 1.74077 27.8
16 -138.758 0.16
17 -117.843 3.47 1.77250 49.6
18 -15.935 0.20
19 * -48.747 2.72 1.58313 59.4
20 -20.245 0.00
21 (Flare cut diaphragm)
Image plane ∞

Aspheric data 19th surface
B = -2.85508e-005 C = 9.53495e-009 D = -4.04896e-010 E = 0.00000e + 000
F = 0.00000e + 000

Focal length 28.60
Gis Focal Length 66.00
F number 2.91
Angle of view 37.10
Statue height 21.64
Total lens length 92.78
BF 37.73

LA optical system Gis Anti-vibration lens group SP Aperture stop FS Fixed stop

Claims (5)

In an optical system in which the focal length is shorter than the back focus and the lens groups are respectively disposed on the object side and the image side with respect to the aperture stop, a position adjacent to the image side of the aperture stop is perpendicular to the optical axis. An anti-vibration lens group that moves in the direction including the component and moves the image position is disposed, the focal length of the entire system is f, the focal length of the anti-vibration lens group is fis, and the anti-vibration lens from the aperture stop The distance on the optical axis to the lens surface on the aperture stop side of the group is Dis, the distance on the optical axis from the first lens surface on the object side to the final lens surface at the infinite object distance is DL, and the distance from the aperture stop to the final When the distance on the optical axis to the lens surface is _DFS ,
0.1 <f / fis <1.0
0.00 <Dis / DL <0.25
0.3 _<D FS /f<2.0
An optical system characterized by satisfying the following conditions. When the lateral magnification of the anti-vibration lens group is βis, and the lateral magnification of the optical system arranged on the image side of the anti-vibration lens group is βr,
0.1 <| (1-βis) βr | <1.3
The optical system according to claim 1, wherein the following condition is satisfied. When the length on the optical axis of the anti-vibration lens group is Lis,
0.01 <Lis / DL <0.15
The optical system according to claim 1, wherein the following condition is satisfied. When the distance on the optical axis from the first lens surface to the image plane is TL,
1.0 <TL / f <4.5
The optical system according to claim 1, wherein the following condition is satisfied.   An image pickup apparatus comprising the optical system according to claim 1.