JP2007164157A - Zoom lens system, imaging device, and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom lens system that is thin and compact and has a short overall length high resolution and a blur compensation function of optically compensating blur caused in an image by hand shake, vibration, etc., an imaging device including this zoom lens system, and a camera provided with this imaging device. <P>SOLUTION: The zoom lens system comprises a plurality of lens units each of which is composed of at least one lens element, wherein a gap between at least two lens units among these lens unit is changed so that an optical image of an object is formed with a continuously variable magnification, and a first lens unit arranged on the most object side among the lens units includes a lens element having a reflecting surface for bending a light beam from the object, and one of the lens units, one of lens elements, or a plurality of adjacent lens elements constituting one lens unit move in a direction perpendicular to an optical axis. The imaging device includes this zoom lens system, and the camera employs this imaging device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a zoom lens system, an imaging apparatus, and a camera. In particular, the present invention is suitable for a camera such as a small and high-quality digital still camera or digital video camera, has a high resolution, and has a blur correction function for optically correcting image blur due to camera shake, vibration, and the like. The present invention relates to a zoom lens system having an image pickup apparatus, an image pickup apparatus including the zoom lens system, and a thin and compact camera including the image pickup apparatus.

  In recent years, solid-state imaging devices such as high-pixel CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor) have been developed, and an imaging optical system having high optical performance corresponding to these high-pixel solid-state imaging devices has been developed. Digital still cameras and digital video cameras equipped with an image pickup apparatus including them are rapidly spreading.

  Among these, particularly in digital still cameras, recently, a thin configuration with the highest priority on storage and portability has been proposed. As one of means for realizing such a thin digital still camera, a zoom lens system for bending a light beam, and a lens barrel and an image pickup apparatus including the zoom lens system have been proposed.

  For example, Patent Document 1 discloses a fixed first-stage photographing lens, a plurality of movable photographing lens groups following the photographing lens, an optical axis changing means intermediate between the plurality of movable photographing lens groups, and the optical axis changing. There is disclosed a lens barrel provided with driving means for moving a movable photographing lens before and after the means in the direction of the photographing optical axis. In the lens barrel described in Patent Document 1, since the optical axis changing unit is arranged between the plurality of movable photographing lens groups, the first-stage photographing lens and the rear-stage movable photographing lens group are arranged. The interval can be reduced, the diameter of the first-stage photographing lens can be reduced, and the volume of the entire lens barrel can be reduced.

  Patent document 2 includes a plurality of lenses and an optical axis changing unit between the lenses, and includes a photographic lens unit disposed on the subject-side front surface of the image display unit provided on the back surface of the apparatus body. An electronic imaging device that records subject light that has passed through a unit by performing photoelectric conversion with an imaging device is disclosed. In the electronic imaging apparatus described in Patent Document 2, the photographing lens unit includes an optical axis changing unit between the lenses, so that the light beam is bent halfway, and an image display unit is disposed on the back surface thereof. Therefore, it is possible to realize a well-balanced shape in which the apparatus main body is not thick and the lateral dimension is shortened.

In Patent Document 3, zooming is performed by moving the second lens group and the fourth lens group in order of positive, negative, positive, and negative five groups in order from the object side, and the first lens group is negative in order from the object side. A zoom lens system is disclosed that includes an optical member that bends the optical path and a positive rear lens group, and the imaging magnification of the fifth lens group is in a specific range. In the zoom lens system described in Patent Document 3, the first lens group includes a negative front lens group, an optical member that bends the optical path, and a positive rear lens group. Therefore, the second lens when zooming is performed. The moving direction of the group and the fourth lens group is the optical axis direction of the rear lens group of the first lens group, and the lens system is thinned. Further, since the imaging magnification of the fifth lens group is larger than a specific value, the focal length of the lens arranged on the object side can be shortened, the total length of the lens system is shortened, and the first lens is shortened. The effective diameters of the front lens group and the rear lens group of the group can be further reduced.
JP 11-258678 A JP 11-196303 A JP 2004-354869 A

  However, since the lens barrel described in Patent Document 1 includes a photographing lens group that moves in the optical axis direction during zooming, between the first-stage photographing lens positioned closest to the object side and the optical axis exchanging means. It cannot be said that the entire lens barrel is sufficiently downsized. In addition, there is no specificity of the zoom lens system itself held by the lens barrel, and it is difficult to consider that the zoom lens system is compatible with blur correction.

  In addition, the electronic imaging device described in Patent Document 2 is not specific to the photographing lens unit itself, and it is difficult to think that the camera shake correction function is sufficiently provided. In addition, the distance between the lens eyepiece and the release switch is small. They are separated from each other, and image blur due to camera shake is likely to occur.

  The zoom lens system described in Patent Document 3 is a lens system having a specific five-group configuration. Although it is certainly a lens system that is thin and has a reduced overall length, its blur correction function can still be satisfied. In addition, there is a problem that sufficient optical performance cannot be maintained when blur correction is performed.

  An object of the present invention includes a zoom lens system having a blur correction function for optically correcting image blur due to camera shake, vibration, and the like, as well as having a short overall length, thin and compact, and high resolution, and the zoom lens system An imaging device and a camera including the imaging device are provided.

One of the above objects is achieved by the following zoom lens system. That is, the present invention
A zoom lens system having a plurality of lens groups each including at least one lens element,
An optical image of the object is formed so as to be continuously variable by changing the interval between at least any two of the lens groups,
Among the lens groups, the first lens group disposed on the most object side includes a lens element having a reflecting surface that bends light rays from the object,
The present invention relates to a zoom lens system in which any one of the lens groups, any one of the lens elements, or a plurality of adjacent lens elements constituting one lens group move in a direction perpendicular to the optical axis.

One of the above objects is achieved by the following imaging device. That is, the present invention
An imaging apparatus capable of outputting an optical image of an object as an electrical image signal,
A zoom lens system that forms an optical image of the object;
An image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
A plurality of lens groups each including at least one lens element;
An optical image of the object is formed so as to be continuously variable by changing the interval between at least any two of the lens groups,
Among the lens groups, the first lens group disposed on the most object side includes a lens element having a reflecting surface that bends light rays from the object,
An imaging apparatus in which any one of the lens groups, any one of the lens elements, or a plurality of adjacent lens elements constituting one lens group moves in a direction perpendicular to the optical axis. About.

One of the above objects is achieved by the following camera. That is, the present invention
A camera that converts an optical image of an object into an electrical image signal, and displays and stores the converted image signal;
An image pickup apparatus including a zoom lens system that forms an optical image of an object, and an image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
A plurality of lens groups each including at least one lens element;
An optical image of the object is formed so as to be continuously variable by changing the interval between at least any two of the lens groups,
Among the lens groups, the first lens group disposed on the most object side includes a lens element having a reflecting surface that bends light rays from the object,
The present invention relates to a camera in which any one of the lens groups, any one of the lens elements, or a plurality of adjacent lens elements constituting one lens group move in a direction perpendicular to the optical axis. .

  According to the present invention, it is possible to provide a zoom lens system that has not only a short overall length, a thin compact size, and a high resolution, but also a blur correction function that optically corrects image blur due to camera shake and vibration. Further, according to the present invention, a thin imaging device including the zoom lens system and having a high-resolution blur correction function, and the imaging device, and having a short start-up time, a dustproof / waterproof effect, and particularly a depth Can provide a small camera.

(Embodiment 1)
First, in the first embodiment, an imaging including a zoom lens system that forms an optical image of an object and an image sensor that converts an optical image formed by the zoom lens system into an electrical image signal. A schematic configuration of a camera to which the apparatus is applied will be described.

  FIG. 1 is a transparent perspective view illustrating a schematic configuration of an imaging state of a camera to which the imaging apparatus according to Embodiment 1 is applied. FIG. 1 is a diagram schematically illustrating the imaging apparatus according to the first embodiment, and the scale and relative relationship are different from actual ones.

  In FIG. 1, a camera to which the imaging apparatus according to Embodiment 1 is applied includes a housing 1, an imaging element 2, a shutter button 3, and a lens element 5 having a reflecting surface, and is disposed closest to the object side. A first lens group 4 and an image side lens group 6 disposed on the image side of the first lens group 4 are provided. Among these, the first lens group 4 and the image side lens group 6 constitute a zoom lens system, and form an optical image of an object on the light receiving surface of the image sensor 2. Among these, the zoom lens system is held by a lens holding cylinder in the lens barrel, and the zoom lens system held by the lens holding cylinder and the imaging device 2 constitute an imaging device. Therefore, the camera includes a housing 1 and an imaging device including a zoom lens system and an imaging device 2.

  In the imaging state of the camera according to Embodiment 1, the imaging element 2 is an imaging sensor such as a CCD or a CMOS, and generates an electrical image signal based on an optical image formed on the light receiving surface by the zoom lens system. Output. The shutter button 3 is disposed on the upper side surface of the housing 1 and determines the acquisition timing of the image signal of the image sensor 2 when operated by an operator. The lens element 5 has a reflecting surface that bends light rays from the object, in particular, a reflecting surface 5a that bends the optical axis AX1 (axial principal ray from the object) of the first lens group 4 by approximately 90 °. Is deflected to the image side lens group 6. The image side lens group 6 is disposed on the optical axis AX2, and transmits the object light deflected by the reflecting surface 5a to the image sensor 2.

  In the zoom lens system provided in the camera according to Embodiment 1, the first lens group 4 includes the lens element 5 having the reflective surface 5a, and the light from the object is bent by the reflective surface 5a. The zoom lens system can be made thin in the optical axis direction of the axial light beam from the object. Therefore, for example, in the case of a zoom lens system having a variable total length, the first lens group including the lens element having a reflecting surface and the at least one image side lens group are moved from the position of the imaging state and retracted without being retracted. In the image pickup state, the storage state can be generally achieved. Further, for example, in the case of a zoom lens system with a fixed full length, the retracted state can be achieved in a state close to the imaging state at the wide-angle end.

  The lens barrel including the zoom lens system according to Embodiment 1 includes a normal main body, a first lens group holding cylinder, a holding cylinder holding each of at least one image side lens group, and a guide shaft. In the imaging state, all the components of the imaging device are disposed and held in the holding cylinders inside the main body, and in the storage state, all the configurations of the imaging device are stored in the main body as they are.

  When the zoom lens system according to Embodiment 1 is in the imaging state at the telephoto end, the first lens group holding cylinder and the holding cylinder that holds at least one image-side lens group are bent at the reflecting surface at the telephoto end. Are arranged at predetermined positions on the optical axis of light rays from the object (hereinafter referred to as reflected object light).

  When the zoom lens system according to Embodiment 1 shifts from the telephoto end imaging state to the wide-angle end imaging state, the holding cylinder that holds each image-side lens group is guided by the guide shaft while the optical axis of the reflected object light Are respectively stopped at predetermined positions on the optical axis of the reflected object light at the wide-angle end. During this period, the first lens group holding cylinder is preferably fixed. As described above, for example, in the case of a zoom lens system having a variable total length, the imaging state at the wide-angle end, that is, the first lens group and the second lens group disposed immediately on the image side of the first lens group. The storage state can be set when the interval is stopped at a position where the interval is substantially minimized. Further, for example, in the case of a zoom lens system having a fixed full length, the distance between the first lens group and the second lens group disposed immediately on the image side of the first lens group is close to the imaging state at the wide-angle end. When the vehicle stops at a position close to the minimum, the storage state can be set.

  Conversely, when the zoom lens system according to Embodiment 1 shifts from the wide-angle end imaging state to the telephoto end imaging state, the holding cylinder that holds each of the image side lens groups is guided by the guide shaft while reflecting the reflected object light. It moves along the optical axis and stops at a predetermined position on the optical axis of the reflected object light at the telephoto end. During this time, it is preferable that the first lens group holding cylinder is also fixed. Then, the first lens group is stopped at a position where the distance between the first lens group and the second lens group disposed immediately on the image side is maximized, and the telephoto end imaging state is obtained.

  As described above, the zoom lens system according to Embodiment 1 includes a lens element having a reflecting surface that can bend a light beam from an object, in particular, can bend an axial principal ray from the object by approximately 90 °. Since it is included in the first lens group arranged closest to the object side, the zoom lens system can be made thin in the optical axis direction of the axial light beam from the object in the imaging state, and the imaging device and the camera are thin. Is realized.

  In addition, the aspect of the lens element which has the said reflective surface is not specifically limited. The lens element having a reflecting surface may be any of, for example, a surface reflecting prism, a parallel plate-shaped internal reflecting mirror, a parallel plate-shaped surface reflecting mirror, and a prism or mirror having optical power is particularly preferable. The reflective surface may be formed by any known method such as vapor deposition of a metal such as aluminum or formation of a dielectric multilayer film. Furthermore, the reflecting surface does not need to have a reflectivity of 100%, and the light for measuring light and the light for the optical viewfinder optical system are branched from the light from the object, or the autofocus auxiliary light is passed through the reflecting surface. The reflectance may be set as appropriate, for example, by using it as part of an optical path for projecting light.

  Further, the configuration of the first lens group is not particularly limited as long as the lens element having the reflection surface is included, but in order from the object side to the image side, for example, a lens element having negative optical power, and a reflection surface are provided. Preferably, it comprises a lens element comprising and a subsequent lens element comprising at least one lens element and having a positive optical power.

(Embodiment 2)
The image pickup apparatus according to the second embodiment is the same as the image pickup apparatus according to the first embodiment, but the arrangement direction layout of the optical axis of the reflected object light is different when arranged on the camera. That is, the camera to which the imaging apparatus according to Embodiment 1 is applied adopts a layout in which the optical axis of the reflected object light is arranged perpendicular to the stroke direction of the shutter button and the imaging apparatus is placed horizontally. In contrast, a camera to which the imaging apparatus according to Embodiment 2 is applied employs a layout in which the optical axis of the reflected object light is arranged in parallel with the stroke direction of the shutter button and the imaging apparatus is placed vertically. ing.

  As described above, the imaging apparatus according to Embodiment 2 can increase the degree of freedom in arrangement when applied to a camera, and can improve the degree of freedom in creating a camera design.

  Note that the lens barrel applied to the imaging apparatus according to the second embodiment is similar to the lens barrel applied to the imaging apparatus according to the first embodiment, for example, in the case of a zoom lens system having a variable overall length. Shifts from the telephoto end imaging state to the wide-angle end imaging state, and the wide-angle end imaging state, that is, the first lens group and the second lens group disposed immediately on the image side of the first lens group. The storage state can be set when the interval is stopped at a position where the interval is substantially minimized. Further, for example, in the case of a zoom lens system having a fixed full length, the distance between the first lens group and the second lens group disposed immediately on the image side of the first lens group is close to the imaging state at the wide-angle end. When the vehicle stops at a position close to the minimum, the storage state can be set.

(Embodiments 3 to 7)
Hereinafter, a zoom lens system applicable to the imaging apparatuses of Embodiments 1 and 2 will be described in more detail with reference to the drawings. FIG. 2 is a lens arrangement diagram of the zoom lens system according to Embodiment 3. FIG. 5 is a lens arrangement diagram of the zoom lens system according to Embodiment 4. FIG. 8 is a lens arrangement diagram of the zoom lens system according to Embodiment 5. FIG. 11 is a lens arrangement diagram of the zoom lens system according to Embodiment 6. FIG. 14 is a lens layout diagram of the zoom lens system according to Embodiment 7. 2, 5, 8, 11, and 14, (a) is a lens configuration at the wide angle end (shortest focal length state: focal length f _W ), and (b) is an intermediate position (intermediate focal length state: focal length f _M =). √ (f _W * f _T )), and (c) shows the lens configuration at the telephoto end (longest focal length state: focal length f _T ).

  In each of the zoom lens systems according to Embodiments 3 to 6, the first lens group G1 having a positive optical power and the second lens group G2 having a negative optical power are sequentially arranged from the object side to the image side. And a stop A, a third lens group G3 having positive optical power, and a fourth lens group G4 having positive optical power. The zoom lens system according to Embodiment 7 includes, in order from the object side to the image side, a first lens group G1 having a negative optical power, a diaphragm A, and a second lens group having a positive optical power. G2 and a third lens group G3 having positive optical power.

  Note that the second lens element L2 in each embodiment has a configuration corresponding to a lens element having a reflective surface, and the position of the reflective surface is omitted. In FIGS. 2, 5, 8, 11 and 14, the straight line shown on the rightmost side in the drawing represents the position of the image plane S. On the object side, an optical low-pass filter or A parallel plate P equivalent to the face plate or the like of the image sensor is provided. In the zoom lens systems according to Embodiments 3 to 7, these lens groups are arranged in a desired power arrangement, whereby the entire lens system can be reduced in size while maintaining high optical performance.

  As shown in FIG. 2, in the zoom lens system according to Embodiment 3, the first lens group G1 is a negative meniscus first lens element L1 having a convex surface directed toward the object side in order from the object side to the image side. And a lens element L2 having both a plane of incidence and a plane of incidence and having a reflecting surface, and a biconvex third lens element L3.

  In the zoom lens system according to Embodiment 3, the second lens group G2 includes, in order from the object side to the image side, a biconcave fourth lens element L4 and a positive meniscus second lens element having a convex surface directed toward the object side. 5 lens elements L5.

  In the zoom lens system according to Embodiment 3, the third lens unit G3 includes, in order from the object side to the image side, a positive meniscus sixth lens element L6 having a convex surface directed toward the object side, and a biconvex shape. It consists of a seventh lens element L7 and a biconcave eighth lens element L8. Among these, the seventh lens element L7 and the eighth lens element L8 are cemented.

  In the zoom lens system according to Embodiment 3, the fourth lens unit G4 comprises solely a positive meniscus ninth lens element L9 with the convex surface facing the object side.

  In the zoom lens system according to Embodiment 3, when zooming from the wide-angle end to the telephoto end, the second lens group G2 moves toward the image side, the third lens group G3 moves toward the object side, The lens group G4 moves along a locus convex toward the object side while changing the distance from the third lens group G3, and the first lens group G1 is fixed with respect to the image plane S.

  As shown in FIG. 5, in the zoom lens system according to Embodiment 4, the first lens unit G1 includes a negative meniscus first lens element L1 having a convex surface directed toward the object side in order from the object side to the image side. And a lens element L2 having a flat incident surface and a reflecting surface and having a reflecting surface, and a positive meniscus third lens element L3 having a convex surface facing the object side.

  In the zoom lens system according to Embodiment 4, the second lens group G2 includes, in order from the object side to the image side, a negative meniscus fourth lens element L4 with a convex surface directed toward the object side, and a biconcave second lens element L4. It consists of five lens elements L5 and a biconvex sixth lens element L6.

  In the zoom lens system according to Embodiment 4, the third lens unit G3 includes, in order from the object side to the image side, a positive meniscus seventh lens element L7 having a convex surface directed toward the object side, and a biconvex shape. It consists of an eighth lens element L8 and a biconcave ninth lens element L9. Among these, the eighth lens element L8 and the ninth lens element L9 are cemented.

  In the zoom lens system according to Embodiment 4, the fourth lens unit G4 comprises solely a positive meniscus tenth lens element L10 with the convex surface facing the object side.

  In the zoom lens system according to Embodiment 4, when zooming from the wide-angle end to the telephoto end, the second lens group G2 moves to the image side, and the third lens group G3 and the fourth lens group G4 are on the object side. The first lens group G1 is fixed with respect to the image plane S.

  As shown in FIG. 8, in the zoom lens system according to Embodiment 5, the first lens unit G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface directed toward the object side. And a lens element L2 having both a plane of incidence and a plane of incidence and having a reflecting surface, and a biconvex third lens element L3.

  In the zoom lens system according to Embodiment 5, the second lens unit G2 includes, in order from the object side to the image side, a negative meniscus fourth lens element L4 with a convex surface directed toward the object side, and a biconcave second lens element L4. 5 lens elements L5 and a positive meniscus sixth lens element L6 having a convex surface facing the object side.

  In the zoom lens system according to Embodiment 5, the third lens unit G3 includes, in order from the object side to the image side, a positive meniscus seventh lens element L7 with a convex surface facing the object side, and a convex surface facing the object side And a negative meniscus ninth lens element L9 having a convex surface facing the object side. Among these, the eighth lens element L8 and the ninth lens element L9 are cemented.

  In the zoom lens system according to Embodiment 5, the fourth lens unit G4 comprises solely a positive meniscus tenth lens element L10 with the convex surface facing the object side.

  In the zoom lens system according to Embodiment 5, when zooming from the wide-angle end to the telephoto end, the second lens group G2 moves to the image side, and the third lens group G3 and the fourth lens group G4 are on the object side. The first lens group G1 is fixed with respect to the image plane S.

  As shown in FIG. 11, in the zoom lens system according to Embodiment 6, the first lens unit G1 includes, in order from the object side to the image side, a negative meniscus first lens element L1 having a convex surface directed toward the object side. And a lens element L2 having both a plane of incidence and a plane of incidence and having a reflecting surface, and a biconvex third lens element L3.

  In the zoom lens system according to Embodiment 6, the second lens unit G2 includes, in order from the object side to the image side, a negative meniscus fourth lens element L4 with a convex surface directed toward the object side, and a biconcave second lens element L4. It consists of five lens elements L5 and a biconvex sixth lens element L6.

  In the zoom lens system according to Embodiment 6, the third lens unit G3 includes, in order from the object side to the image side, a biconvex seventh lens element L7, a biconvex eighth lens element L8, It comprises a biconcave ninth lens element L9. Among these, the eighth lens element L8 and the ninth lens element L9 are cemented.

  In the zoom lens system according to Embodiment 6, the fourth lens unit G4 comprises solely a positive meniscus tenth lens element L10 with the convex surface facing the object side.

  In the zoom lens system according to Embodiment 6, when zooming from the wide-angle end to the telephoto end, the second lens group G2 and the fourth lens group G4 move toward the image side, and the third lens group G3 moves toward the object side. The first lens group G1 is fixed with respect to the image plane S.

  As shown in FIG. 14, in the zoom lens system according to Embodiment 7, the first lens group G1 includes a biconcave first lens element L1, an entrance surface, and an exit surface in order from the object side to the image side. Both lens elements L2 are flat and have a reflecting surface, and a biconvex third lens element L3.

  In the zoom lens system according to Embodiment 7, the second lens unit G2 includes, in order from the object side to the image side, a positive meniscus fourth lens element L4 with a convex surface facing the object side, and a convex surface facing the object side. And a negative meniscus sixth lens element L6 with a convex surface facing the object side. Among these, the fifth lens element L5 and the sixth lens element L6 are cemented.

  In the zoom lens system according to Embodiment 7, the third lens unit G3 comprises solely a bi-convex seventh lens element L7.

  In the zoom lens system according to Embodiment 7, when zooming from the wide-angle end to the telephoto end, the second lens group G2 moves toward the object side, the third lens group G3 moves toward the image side, The lens group G1 is fixed with respect to the image plane S.

  As described above, the zoom lens systems according to Embodiments 3 to 7 have a plurality of lens groups each including at least one lens element, and the first lens group G1 has a reflective surface for bending light rays from an object. However, the number of lens groups constituting the zoom lens system is not particularly limited, and may be a four-group configuration or a three-group configuration as in the third to seventh embodiments. It may be.

  In the case of a four-group zoom lens system having four lens groups, a first lens group having positive optical power and a second lens having negative optical power in order from the object side to the image side. And a subsequent lens group including at least one lens group having a positive optical power. For example, as in the third to sixth embodiments, the subsequent lens group moves from the object side to the image side. In particular, it is particularly preferable to include a third lens group having a positive optical power and a fourth lens group having a positive optical power.

  In the case of a zoom lens system having a three-group configuration having three lens groups, a first lens group having negative optical power and a lens group having positive optical power are sequentially arranged from the object side to the image side. It is preferable to include at least one subsequent lens group. For example, as in the seventh embodiment, the subsequent lens group includes a second lens group having a positive optical power in order from the object side to the image side. And a third lens group having positive optical power is particularly preferable.

  Further, as in the third to seventh embodiments, in a zoom lens system having a four-group configuration having four lens groups and a zoom lens system having a three-group configuration having three lens groups, from the wide-angle end to the telephoto end during imaging. In the zooming, it is preferable that the first lens group including the lens element having the reflecting surface is fixed with respect to the image plane S without moving in the optical axis direction.

  In the zoom lens systems according to Embodiments 3 to 7, zooming is performed by changing the interval between at least any two of the plurality of lens groups. When one or any of the plurality of adjacent lens elements constituting one lens group moves in the direction perpendicular to the optical axis, image blur due to camera shake, vibration, or the like is optically corrected.

  In each embodiment, the movement in the direction perpendicular to the optical axis is any one of a plurality of lens groups constituting a zoom lens system, any one of lens elements constituting a lens group, or A plurality of adjacent lens elements constituting one lens group. As described above, when any one of the lens groups, any one of the lens elements, or a plurality of adjacent lens elements constituting one lens group move in the direction perpendicular to the optical axis, the zoom lens system Image blur correction can be performed while maintaining excellent imaging characteristics with small decentration coma and decentering astigmatism while suppressing an increase in overall size.

  In each embodiment, any one of the lens groups not including the lens element having the reflecting surface, that is, any one of the lens groups other than the first lens group, or any one of the lens elements other than the lens element having the reflecting surface is used. Alternatively, when a plurality of adjacent lens elements other than the lens elements having a reflecting surface constituting one lens group move in a direction perpendicular to the optical axis, the entire zoom lens system is configured more compactly. It is preferable from the viewpoint that image blur can be corrected while maintaining excellent imaging characteristics, and in particular, any one of the lens groups other than the first lens group is perpendicular to the optical axis. It is preferable to move in the direction.

  Further, in each embodiment, the adjacent lens elements that constitute any one of the lens groups or one lens group that move in the direction perpendicular to the optical axis are configured by three lens elements. It is preferable from the viewpoint that image blur can be corrected more sufficiently while maintaining excellent imaging characteristics.

  Further, in the case of a four-group zoom lens system having four lens groups as in the third to sixth embodiments, the entire third lens group or a part of the lens elements constituting the third lens group is on the optical axis. However, in the case of a zoom lens system having a three-group configuration having three lens groups as in the seventh embodiment, the entire second lens group or the second lens group is configured. It is preferable that the lens element of the part moves in a direction perpendicular to the optical axis.

  Hereinafter, for example, as in the zoom lens systems according to Embodiments 3 to 7, a plurality of lens groups each including at least one lens element are provided, and at least two of these lens groups are spaced from each other. Zooming is performed by changing, and among these lens groups, the first lens group includes a lens element having a reflective surface, and any one of these lens groups, any one of the lens elements, or one The following description is given for a preferable condition that a zoom lens system in which a plurality of adjacent lens elements constituting a lens group move in a direction perpendicular to the optical axis is satisfied. A plurality of preferable conditions are defined for the zoom lens system according to each embodiment, but a zoom lens system configuration that satisfies all of the plurality of conditions is most desirable. However, by satisfying individual conditions, it is possible to obtain a zoom lens system that exhibits the corresponding effects.

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (1).
0.2 <P _W / Y _W × 10 ⁻³ <1.7 (1)
(However, Z = f _T / f _W > 2.5)
here,
P _W : Distance on the optical axis between the reflecting surface and the object side principal point of the lens group or lens element moving in the direction perpendicular to the optical axis at the wide angle end,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (1) is a condition for defining a distance on the optical axis from a lens element having a reflecting surface to a lens group or a lens element that moves in a direction perpendicular to the optical axis. When the upper limit of condition (1) is exceeded, the distance on the optical axis from the lens element having the reflecting surface to the lens group or lens element that moves in the direction perpendicular to the optical axis becomes longer, and accordingly the zoom lens Since the total length of the system also becomes long, it becomes difficult to provide a compact zoom lens system. On the other hand, if the lower limit of the condition (1) is not reached, the lens correction amount becomes large, so that the correction becomes excessive and there is a possibility that the optical performance is greatly deteriorated.

In addition, the above effect can be further achieved by satisfying at least one of the following conditions (1) ′ and (1) ″.
0.2 <P _W / Y _W × 10 ⁻³ <0.4 (1) ′
1.0 <P _W / Y _W × 10 ⁻³ <1.7 (1) ″
(However, Z = f _T / f _W > 2.5)

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (2).
0.4 <f ₁ / Y _W × 10 ⁻³ <1.5 (2)
(However, Z = f _T / f _W > 2.5)
here,
f ₁ : Composite focal length of the first lens group,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (2) is a condition regarding aberration performance at the time of blur correction. Exceeding the upper limit of the condition (2) is not preferable because the aberration variation of the entire zoom lens system becomes large, and particularly coma aberration may occur greatly. On the other hand, below the lower limit of the condition (2), the diameter of the first lens group including the lens element having the reflecting surface becomes large, and it becomes difficult to provide a compact zoom lens system.

In addition, the above effect can be further achieved by further satisfying at least one of the following conditions (2) ′ and (2) ″.
0.4 <f ₁ / Y _W × 10 ⁻³ <0.6 (2) ′
1.0 <f ₁ / Y _W × 10 ⁻³ <1.5 (2) ″
(However, Z = f _T / f _W > 2.5)

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (3).
0.1 <PF / Y _W × 10 ⁻³ <1.0 (3)
(However, Z = f _T / f _W > 2.5)
here,
PF: Distance on the optical axis from the most object side position on the optical axis of the lens element located closest to the object side to the most image side position on the optical axis of the lens element having a reflecting surface,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (3) is a condition related to the thickness in the depth direction of the zoom lens system. If the upper limit of condition (3) is exceeded, the thickness of the zoom lens system in the depth direction increases, making it difficult to provide a compact imaging device or camera. On the other hand, if the lower limit of condition (3) is not reached, it will be difficult to sufficiently secure the prescribed distance including the lens element having the reflecting surface.

The above effect can be further achieved by further satisfying at least one of the following conditions (3) ′ and (3) ″.
0.1 <PF / Y _W × 10 ⁻³ <0.3 (3) ′
0.6 <PF / Y _W × 10 ⁻³ <1.0 (3) ″
(However, Z = f _T / f _W > 2.5)

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (4).
1.0 <H _P / H _Y <6.0 (4)
here,
H _P : the thickness of the lens element having the reflecting surface in the optical axis direction,
H _Y : the thickness of the lens group or lens element moving in the direction perpendicular to the optical axis in the optical axis direction.

  The condition (4) is a condition relating to the size of the lens element having a reflecting surface. If the upper limit of the condition (4) is exceeded, the lens element having the reflecting surface becomes large, and it becomes difficult to provide a compact zoom lens system. On the other hand, below the lower limit of the condition (4), the thickness of the lens group or lens element moving in the direction perpendicular to the optical axis increases in the optical axis direction, making it difficult to correct blur.

In addition, the above effect can be further achieved by satisfying at least one of the following conditions (4) ′ and (4) ″.
1.0 <H _P / H _Y <3.0 (4) ′
4.5 <H _P / H _Y <6.0 (4) ''

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (5).
0.3 <M _Y / H _P <0.6 (5)
here,
M _Y : The amount of movement in the optical axis direction of the lens group or lens element that moves in the direction perpendicular to the optical axis in zooming from the wide-angle end to the telephoto end,
H _P : Thickness in the optical axis direction of a lens element having a reflecting surface.

  The condition (5) is a condition that defines the amount of movement in the optical axis direction of the lens group or lens element that moves in the direction perpendicular to the optical axis with respect to the thickness in the optical axis direction of the lens element having the reflecting surface. . If the upper limit of condition (5) is exceeded, the amount of movement in the optical axis direction of the lens group or lens element that moves in the direction perpendicular to the optical axis will increase, and accordingly the overall length of the zoom lens system will also increase. Therefore, it becomes difficult to provide a compact zoom lens system. On the other hand, if the lower limit of the condition (5) is not reached, the thickness of the lens element having the reflecting surface in the optical axis direction becomes large, and it becomes difficult to provide a compact zoom lens system.

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (6).
0.1 <M _Y / Y _W × 10 ⁻³ <0.4 (6)
(However, Z = f _T / f _W > 2.5)
here,
M _Y : The amount of movement in the optical axis direction of the lens group or lens element that moves in the direction perpendicular to the optical axis in zooming from the wide-angle end to the telephoto end,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (6) is that the light of the lens group or lens element moving in the direction perpendicular to the optical axis with respect to the movement amount at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis. This is a condition that defines the amount of movement in the axial direction. If the upper limit of condition (6) is exceeded, the amount of movement of the lens group or lens element moving in the direction perpendicular to the optical axis in the direction of the optical axis increases, and accordingly the overall length of the zoom lens system also increases. Therefore, it becomes difficult to provide a compact zoom lens system. On the other hand, if the lower limit of the condition (6) is not reached, the lens correction amount becomes large, so that the correction becomes excessive and there is a risk of deteriorating the optical performance.

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (7).
6.0 <Y _W / I _V × 10 ³ <9.5 (7)
(However, Z = f _T / f _W > 2.5)
here,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
I _V : Length of the image sensor in the short side direction I _V = 2 × f _W × tan ω _W × 0.60,
f _W : focal length of the entire system at the wide-angle end,
ω _W is the incident half angle of view at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (7) is a condition that defines the amount of movement at the time of maximum blur correction of the lens group or lens element that moves in the direction perpendicular to the optical axis. If the upper limit of the condition (7) is exceeded, the lens correction amount increases, so that the correction becomes excessive and there is a risk of deteriorating the optical performance. On the other hand, if the lower limit of the condition (7) is not reached, it will be difficult to sufficiently correct blur such as camera shake.

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (8).
3.0 <P _W / I _V <11.0 (8)
(However, Z = f _T / f _W > 2.5)
here,
P _W : Distance on the optical axis between the reflecting surface and the object side principal point of the lens group or lens element moving in the direction perpendicular to the optical axis at the wide angle end,
I _V : Length of the image sensor in the short side direction I _V = 2 × f _W × tan ω _W × 0.60,
f _W : focal length of the entire system at the wide-angle end,
ω _W is the incident half angle of view at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (8) is a condition for defining a distance on the optical axis from a lens element having a reflecting surface to a lens group or a lens element that moves in a direction perpendicular to the optical axis. If the upper limit of the condition (8) is exceeded, the distance on the optical axis from the lens element having the reflecting surface to the lens group or lens element moving in the direction perpendicular to the optical axis becomes longer, and accordingly, the zoom lens Since the total length of the system also becomes long, it becomes difficult to provide a compact zoom lens system. On the other hand, below the lower limit of the condition (8), it is difficult to satisfy sufficient aberration performance.

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (9).
0.2 <f _W / H _P <0.9 (9)
(However, Z = f _T / f _W > 2.5)
here,
H _P : the thickness of the lens element having the reflecting surface in the optical axis direction,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (9) is a condition related to the size of the lens element having the reflecting surface. If the upper limit of condition (9) is exceeded, it will be difficult to satisfy sufficient aberration performance. On the other hand, if the lower limit of the condition (9) is not reached, the lens element having the reflecting surface becomes large, and it becomes difficult to provide a compact zoom lens system.

For example, a zoom lens system like the zoom lens system according to Embodiments 3 to 7 desirably satisfies the following condition (10).
2.5 <H _P / I _V <5.0 (10)
(However, Z = f _T / f _W > 2.5)
here,
H _P : the thickness of the lens element having the reflecting surface in the optical axis direction,
I _V : Length of the image sensor in the short side direction I _V = 2 × f _W × tan ω _W × 0.60,
f _W : focal length of the entire system at the wide-angle end,
ω _W is the incident half angle of view at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (10) is a condition relating to the thickness of the lens element having the reflecting surface. If the upper limit of the condition (10) is exceeded, the thickness of the lens element having the reflective surface tends to be large, and the imaging device tends to be large. On the other hand, if the lower limit of the condition (10) is not reached, it is difficult to ensure a sufficient thickness of the lens element having the reflecting surface.

Furthermore, the above effect can be further achieved by further satisfying at least one of the following conditions (10) ′ and (10) ″.
2.5 <H _P / I _V <3.0 (10) ′
4.0 <H _P / I _V <5.0 (10) ''
(However, Z = f _T / f _W > 2.5)

Further, for example, as in the zoom lens systems according to Embodiments 3 to 6, the first lens group including a lens element having a reflecting surface in order from the object side to the image side and having positive optical power; A zoom lens system having four lens groups, including a second lens group having optical power, a third lens group having positive optical power, and a fourth lens group having positive optical power, It is desirable that the following condition (11) is satisfied.
0.5 <− (1-m _2T ) × m _3T × m _4T <2.0 (11)
(However, Z = f _T / f _W > 2.5)
here,
m _2T : magnification of the second lens unit at the telephoto end when the shooting distance is ∞,
m _3T : magnification of the third lens unit at the telephoto end when the shooting distance is ∞,
m _4T : Magnification of the fourth lens unit at the telephoto end when the shooting distance is ∞,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (11) is a condition for improving the imaging characteristics at the time of blur correction. If the upper limit of the condition (11) is exceeded, the amount of decentering of the lens group or lens element that moves in the direction perpendicular to the optical axis, which is necessary to decenter the image by a predetermined amount, becomes too small, and the translation is accurately performed. It becomes difficult. On the other hand, if the lower limit of condition (11) is not reached, the amount of decentration of the lens group or lens element that moves in the direction perpendicular to the optical axis, which is necessary to decenter the image by a predetermined amount, becomes excessive. Change tends to be large, and the imaging characteristics of the peripheral portion of the image tend to deteriorate.

In addition, the above effect can be further achieved by satisfying at least one of the following conditions (11) ′ and (11) ″.
1.0 <-(1-m _2T ) × m _3T × m _4T (11) ′
-(1-m _2T ) × m _3T × m _4T <1.5 (11) ''
(However, Z = f _T / f _W > 2.5)

Further, for example, as in the zoom lens systems according to Embodiments 3 to 6, the first lens group including a lens element having a reflecting surface in order from the object side to the image side and having positive optical power; A zoom lens system having four lens groups, including a second lens group having optical power, a third lens group having positive optical power, and a fourth lens group having positive optical power, It is desirable to satisfy the following condition (12).
1.5 <f ₁ / f ₃ <3.5 (12)
(However, Z = f _T / f _W > 2.5)
here,
f ₁ : Composite focal length of the first lens group,
f ₃ : composite focal length of the third lens group,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (12) is a condition that defines a ratio between the combined focal length of the first lens group and the combined focal length of the third lens group. Exceeding the upper limit of the condition (12) tends to increase coma aberration, which is not preferable. On the other hand, if the lower limit of condition (12) is not reached, the thickness of the first lens group in the optical axis direction becomes large, and it becomes difficult to provide a compact zoom lens system.

In addition, the above effect can be further achieved by satisfying at least one of the following conditions (12) ′ and (12) ″.
2.0 <f ₁ / f ₃ (12) ′
f ₁ / f ₃ <3.0 (12) ''
(However, Z = f _T / f _W > 2.5)

Further, for example, as in the zoom lens systems according to Embodiments 3 to 6, the first lens group including a lens element having a reflecting surface in order from the object side to the image side and having positive optical power; A zoom lens system having four lens groups, including a second lens group having optical power, a third lens group having positive optical power, and a fourth lens group having positive optical power, It is desirable that the following condition (13) is satisfied.
1.0 <−f ₁ / f ₂ <4.0 (13)
(However, Z = f _T / f _W > 2.5)
here,
f ₁ : Composite focal length of the first lens group,
f ₂ : composite focal length of the second lens group,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  The condition (13) is a condition that defines a ratio between the combined focal length of the first lens group and the combined focal length of the second lens group. Exceeding the upper limit of the condition (13) is not preferable because aberration variation of the entire zoom lens system increases. On the other hand, if the lower limit of condition (13) is not reached, the thickness of the first lens group in the optical axis direction becomes large, and it becomes difficult to provide a compact zoom lens system.

Furthermore, the above effect can be further achieved by further satisfying at least one of the following conditions (13) ′ and (13) ″.
1.0 <−f ₁ / f ₂ <1.5 (13) ′
2.5 <−f ₁ / f ₂ <4.0 (13) ″
(However, Z = f _T / f _W > 2.5)

Further, for example, as in the zoom lens systems according to Embodiments 3 to 6, in order from the object side to the image side, a first lens group having a positive power, a second lens group having a negative power, and a positive lens A zoom lens system including a third lens group having power and a fourth lens group having positive power preferably satisfies the following condition (14).
2.5 <f ₄ / f _W <4.5 (14)
(However, Z = f _T / f _W > 2.5)
here,
f ₄ : composite focal length of the fourth lens group,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  Condition (14) is a condition that defines the focal length of the fourth lens group. If the upper limit of condition (14) is exceeded, it will be difficult to correct spherical aberration and field curvature in the entire zoom lens system in a balanced manner. On the other hand, if the lower limit of the condition (14) is not reached, the amount of movement when performing focusing tends to increase.

In addition, the above effect can be further achieved by satisfying at least one of the following conditions (14) ′ and (14) ″.
3.0 <f ₄ / f _W (14) ′
f ₄ / f _W <3.5 (14) ''
(However, Z = f _T / f _W > 2.5)

Further, for example, as in the zoom lens systems according to Embodiments 3 to 6, in order from the object side to the image side, a first lens group having a positive power, a second lens group having a negative power, and a positive lens A zoom lens system including a third lens group having power and a fourth lens group having positive power desirably satisfies the following condition (15).
0.9 <β _T4 / β _W4 <1.2 (15)
(However, Z = f _T / f _W > 2.5, β _T4 / β _W4 ≠ 0)
here,
β _T4 : magnification of the fourth lens group in the infinite focus state at the telephoto end,
β _W4 : magnification of the fourth lens group in the infinite focus state at the wide angle end,
f _T : focal length of the entire system at the telephoto end,
f _W : the focal length of the entire system at the wide angle end.

  Condition (15) is a condition that regulates the magnification change of the fourth lens group and regulates the zoom contribution of the fourth lens group. If the upper limit of condition (15) is exceeded, it will be difficult to correct aberrations in the entire zoom lens system in a balanced manner. On the other hand, below the lower limit of the condition (15), it becomes difficult to obtain a desired zoom ratio.

In addition, when the following condition (15) ′ is further satisfied, the above effect can be further achieved.
1.0 <β _T4 / β _W4 (15) ′
(However, Z = f _T / f _W > 2.5, β _T4 / β _W4 ≠ 0)

Further, for example, as in the zoom lens systems according to Embodiments 3 to 6, in order from the object side to the image side, a first lens group having a positive power, a second lens group having a negative power, and a positive lens A zoom lens system including a third lens group having power and a fourth lens group having positive power desirably satisfies the following condition (16).
0.5 <f ₃ / f ₄ <1.2 (16)
(However, Z = f _T / f _W > 2.5)
here,
f ₃ : composite focal length of the third lens group,
f ₄ : composite focal length of the fourth lens group,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.

  Condition (16) defines the ratio of the focal lengths of the third lens group and the fourth lens group and defines the function of each lens group during zooming. If the upper limit of condition (16) is exceeded, the zooming action of the third lens group will decrease, making it difficult to obtain the desired zoom ratio. On the other hand, when the value goes below the lower limit of the condition (16), it is difficult to correct astigmatism in the entire zoom lens system.

Furthermore, the above effect can be further achieved by further satisfying at least one of the following conditions (16) ′ and (16) ″.
0.5 <f ₃ / f ₄ <0.8 (16) ′
1.0 <f ₃ / f ₄ <1.2 (16) ''
(However, Z = f _T / f _W > 2.5)

  In each of the zoom lens systems according to Embodiments 3 to 6, the first lens group G1 having a positive optical power and the second lens group G2 having a negative optical power are sequentially arranged from the object side to the image side. A positive, negative and positive four-component zoom lens system including a stop A, a third lens group G3 having positive optical power, and a fourth lens group G4 having positive optical power. The zoom lens system according to Embodiment 7 includes, in order from the object side to the image side, a first lens group G1 having negative optical power, a diaphragm A, and a second lens group G2 having positive optical power. The zoom lens system has a negative-positive-positive three-component configuration including the third lens group G3 having positive optical power, but is not limited thereto. For example, various configurations such as a negative / positive / negative three-component configuration, a positive / negative / positive / three-component configuration, a positive / negative / positive / four-component configuration, and a positive / negative / positive / positive five-component configuration are possible. It can be suitably used for the imaging device shown in Embodiments 1 and 2.

  Each lens group constituting the zoom lens system according to Embodiments 3 to 7 includes a refractive lens element that deflects incident light by refraction (that is, a type in which deflection is performed at an interface between media having different refractive indexes) However, the present invention is not limited to this. For example, a diffractive lens element that deflects incident light by diffraction, a refractive / diffractive hybrid lens element that deflects incident light by a combination of diffractive action and refractive action, and a refractive index that deflects incident light according to the refractive index distribution in the medium Each lens group may be composed of a distributed lens element or the like.

  An imaging apparatus including the zoom lens system according to Embodiments 3 to 7 described above and an imaging element such as a CCD or a CMOS is used as a mobile phone device, a PDA (Personal Digital Assistance), a surveillance camera in a surveillance system, a Web It can be applied to cameras, in-vehicle cameras, and the like.

  In addition, the zoom lens system and the digital still camera according to Embodiments 3 to 7 described above can be used for a digital video camera for moving images. In this case, not only a still image but also a high-resolution moving image can be taken.

ここで、κは円錐定数、Ｄ、Ｅ、Ｆ及びＧは、それぞれ４次、６次、８次及び１０次の非球面係数である。 Hereinafter, numerical examples in which the zoom lens systems according to Embodiments 3 to 7 are specifically implemented will be described. In each numerical example, the unit of length in the table is mm. In each numerical example, r is a radius of curvature, d is a surface interval, nd is a refractive index in the d line, and νd is an Abbe number in the d line. In each numerical example, the surface marked with * is an aspherical surface, and the aspherical shape is defined by the following equation.

Here, κ is a conic constant, and D, E, F, and G are fourth-order, sixth-order, eighth-order, and tenth-order aspheric coefficients, respectively.

  FIG. 3 is a longitudinal aberration diagram of the zoom lens system according to Example 1. FIG. FIG. 6 is a longitudinal aberration diagram of the zoom lens system according to Example 2. FIG. FIG. 9 is a longitudinal aberration diagram of the zoom lens system according to Example 3. 12 is a longitudinal aberration diagram of a zoom lens system according to Example 4. FIG. FIG. 15 is a longitudinal aberration diagram of the zoom lens system according to Example 5;

  In each longitudinal aberration diagram, (a) represents each aberration at the wide-angle end, (b) represents an intermediate position, and (c) represents each aberration at the telephoto end. Each longitudinal aberration diagram shows spherical aberration, astigmatism, and distortion aberration in order from the left side. In the spherical aberration diagram, the vertical axis represents the F number, the solid line is the d line, the short broken line is the F line, and the long broken line is the C line characteristic. In the graph showing astigmatism, the vertical axis represents the half field angle, the solid line represents the sagittal plane (indicated by s in the figure), and the broken line represents the meridional plane (indicated by m in the figure). In the distortion diagram, the vertical axis represents the half angle of view.

  FIG. 4 is a lateral aberration diagram at the telephoto end of the zoom lens system according to Example 1. FIG. 7 is a lateral aberration diagram at the telephoto end of the zoom lens system according to Example 2. FIG. FIG. 10 is a lateral aberration diagram at the telephoto end of the zoom lens system according to Example 3. FIG. 13 is a lateral aberration diagram at the telephoto end of the zoom lens system according to Example 4. FIG. 16 is a lateral aberration diagram at the telephoto end of the zoom lens system according to Example 5. FIGS.

  In each lateral aberration diagram, (a) to (c) are basic states in which image blur correction at the telephoto end is not performed. 4, 7, 10, and 13 correspond to the image blur correction state at the telephoto end in which the entire third lens group G <b> 3 is moved by a predetermined amount in the direction perpendicular to the optical axis. 16D to 16F correspond to image blur correction states at the telephoto end in which the entire second lens group G2 is moved by a predetermined amount in a direction perpendicular to the optical axis. Of each lateral aberration diagram in the basic state, (a) is lateral aberration at an image point of 75% of the maximum image height, (b) is lateral aberration at an axial image point, and (c) is -75% of the maximum image height. Respectively corresponding to lateral aberration at the image point. Of each lateral aberration diagram in the image blur correction state, (d) is lateral aberration at an image point of 75% of the maximum image height, (e) is lateral aberration at an axial image point, and (f) is −− of the maximum image height. Each corresponds to a lateral aberration at an image point of 75%. In each lateral aberration diagram, the horizontal axis represents the distance from the principal ray on the pupil plane, the solid line is the d line, the short broken line is the F line, and the long broken line is the C line characteristic. In the lateral aberration diagrams of FIGS. 4, 7, 10 and 13, the meridional plane is a plane including the optical axis of the first lens group G1 and the optical axis of the third lens group G3. In the aberration diagrams, the meridional plane is a plane including the optical axis of the first lens group G1 and the optical axis of the second lens group G2.

  The amount of movement of the third lens group G3 in the direction perpendicular to the optical axis in the image blur correction state is 0.096 mm in Example 1, 0.094 mm in Example 2, 0.140 mm in Example 3, Example 4 is 0.100 mm, and the amount of movement of the second lens group G2 in the direction perpendicular to the optical axis in the image blur correction state in Example 5 is 0.059 mm. Note that the image decentering amount when the shooting distance is ∞ and the zoom lens system is tilted by 0.3 ° at the telephoto end is such that the entire third lens group G3 or the entire second lens group G2 is perpendicular to the optical axis. It is equal to the amount of image decentering when moving in parallel by the above values.

  As can be seen from the respective lateral aberration diagrams, the symmetry of the lateral aberration at the axial image point is good. Further, when the lateral aberration at the + 75% image point and the lateral aberration at the −75% image point are compared in the basic state, the curvature is small and the inclinations of the aberration curves are almost equal. It can be seen that the aberration is small. This means that sufficient imaging performance is obtained even in the image blur correction state. When the image blur correction angle of the zoom lens system is the same, the amount of parallel movement required for image blur correction decreases as the focal length of the entire zoom lens system decreases. Accordingly, at any zoom position, it is possible to perform sufficient image blur correction without deteriorating the imaging characteristics for an image blur correction angle up to 0.3 °.

Example 1
The zoom lens system of Example 1 corresponds to Embodiment 3 shown in FIG. Table 1 shows lens data of the zoom lens system of Example 1, Table 2 shows focal length, F-number, half angle of view, and variable surface interval data when the shooting distance is ∞, and Table 3 shows aspheric data. .

(Example 2)
The zoom lens system of Example 2 corresponds to Embodiment 4 shown in FIG. Table 4 shows lens data of the zoom lens system of Example 2, Table 5 shows focal length, F number, half angle of view, and variable surface interval data when the shooting distance is ∞, and Table 6 shows aspherical data. .

(Example 3)
The zoom lens system of Example 3 corresponds to Embodiment 5 shown in FIG. Table 7 shows lens data of the zoom lens system of Example 3, Table 8 shows focal length, F number, half angle of view, and variable surface interval data when the shooting distance is ∞, and Table 9 shows aspherical data. .

Example 4
The zoom lens system of Example 4 corresponds to Embodiment 6 shown in FIG. Table 10 shows lens data of the zoom lens system of Example 4, Table 11 shows focal length, F number, half angle of view, and variable surface interval data when the shooting distance is ∞, and Table 12 shows aspheric data. .

(Example 5)
The zoom lens system of Example 5 corresponds to the seventh embodiment shown in FIG. Table 13 shows lens data of the zoom lens system of Example 5, Table 14 shows focal length, F number, half angle of view, and variable surface interval data when the shooting distance is ∞, and Table 15 shows aspherical data. .

Table 16 below shows corresponding values for the above-described conditions.

  The zoom lens system according to the present invention is applicable to digital input devices such as a digital still camera, a digital video camera, a mobile phone device, a PDA (Personal Digital Assistance), a surveillance camera in a surveillance system, a web camera, an in-vehicle camera, It is particularly suitable for cameras that require high image quality, such as digital still cameras and digital video cameras.

FIG. 7 is a transparent perspective view showing a schematic configuration of an imaging state of a camera to which the imaging apparatus according to Embodiment 1 is applied. (A) is a lens arrangement diagram showing an infinitely focused state at the wide-angle end of the zoom lens system according to Embodiment 3 (Example 1), and (b) is related to Embodiment 3 (Example 1). Lens arrangement diagram showing an infinitely focused state at an intermediate position (intermediate focal length state) of the zoom lens system, (c) is an infinite point at the telephoto end of the zoom lens system according to Embodiment 3 (Example 1). Lens layout showing the focus state (A) is a longitudinal aberration diagram in the infinitely focused state at the wide angle end of the zoom lens system according to Example 1, and (b) is an intermediate position (intermediate focal length state) of the zoom lens system according to Example 1. Longitudinal aberration diagram in the infinite focus state, (c) is a vertical aberration diagram in the infinite focus state at the telephoto end of the zoom lens system according to Example 1. FIG. (A) is a lateral aberration diagram at an image point of 75% of the maximum image height in a basic state where image blur correction is not performed at the telephoto end of the zoom lens system according to Example 1, and (b) is a lateral aberration diagram at Example 1. FIG. 4C is a lateral aberration diagram at an on-axis image point in a basic state where image blur correction at the telephoto end of the zoom lens system according to FIG. 6 is not performed; FIG. FIG. 4D is a transverse aberration diagram at an image point of −75% of the maximum image height in the basic state where the zoom is not performed, and FIG. The lateral aberration diagram at% image point, (e) is the lateral aberration diagram at the axial image point in the image blur correction state at the telephoto end of the zoom lens system according to Example 1, and (f) is in Example 1. Maximum image with image blur correction at the telephoto end of such a zoom lens system Lateral aberration diagram at an image point of -75% of (A) is a lens arrangement diagram showing an infinitely focused state at the wide-angle end of the zoom lens system according to Embodiment 4 (Example 2), and (b) is according to Embodiment 4 (Example 2). Lens arrangement diagram showing an infinitely focused state at an intermediate position (intermediate focal length state) of the zoom lens system, (c) is an infinite distance at the telephoto end of the zoom lens system according to Embodiment 4 (Example 2). Lens layout showing the focus state (A) is a longitudinal aberration diagram in the infinitely focused state at the wide angle end of the zoom lens system according to Example 2, and (b) is an intermediate position (intermediate focal length state) of the zoom lens system according to Example 2. Longitudinal aberration diagram in the infinite focus state, (c) is a longitudinal aberration diagram in the infinite focus state at the telephoto end of the zoom lens system according to Example 2. FIG. FIG. 6A is a lateral aberration diagram at an image point of 75% of the maximum image height in a basic state where image blur correction at the telephoto end of the zoom lens system according to Example 2 is not performed; FIG. FIG. 4C is a lateral aberration diagram at an on-axis image point in a basic state where no image blur correction is performed at the telephoto end of the zoom lens system according to FIG. 9C, and FIG. 9C illustrates image blur correction at the telephoto end of the zoom lens system according to Example 2; FIG. 6D is a lateral aberration diagram at an image point of −75% of the maximum image height in the basic state where the zoom is not performed, and FIG. The lateral aberration diagram at% image point, (e) is the lateral aberration diagram at the axial image point in the image blur correction state at the telephoto end of the zoom lens system according to Example 2, and (f) is in Example 2. Maximum image with image blur correction at the telephoto end of such a zoom lens system Lateral aberration diagram at an image point of -75% of (A) is a lens arrangement diagram showing an infinitely focused state at the wide-angle end of a zoom lens system according to Embodiment 5 (Example 3), and (b) is related to Embodiment 5 (Example 3). Lens arrangement diagram showing an infinitely focused state at an intermediate position (intermediate focal length state) of the zoom lens system, (c) is an infinite distance at the telephoto end of the zoom lens system according to Embodiment 5 (Example 3). Lens layout showing the focus state (A) is a longitudinal aberration diagram in the infinitely focused state at the wide angle end of the zoom lens system according to Example 3, and (b) is an intermediate position (intermediate focal length state) of the zoom lens system according to Example 3. Longitudinal aberration diagram in the infinite focus state, (c) is a vertical aberration diagram in the infinite focus state at the telephoto end of the zoom lens system according to Example 3. FIG. 10A is a lateral aberration diagram at an image point of 75% of the maximum image height in a basic state where image blur correction at the telephoto end of the zoom lens system according to Example 3 is not performed; FIG. FIG. 4C is a lateral aberration diagram at an on-axis image point in a basic state where no image blur correction is performed at the telephoto end of the zoom lens system according to FIG. 9C, and FIG. 9C illustrates image blur correction at the telephoto end of the zoom lens system according to Example 3; FIG. 6D is a lateral aberration diagram at an image point of −75% of the maximum image height in the basic state where the zoom is not performed, and FIG. The lateral aberration diagram at% image point, (e) is the lateral aberration diagram at the axial image point in the image blur correction state at the telephoto end of the zoom lens system according to Example 3, and (f) is in Example 3. Maximum image with image blur correction at the telephoto end of such a zoom lens system Lateral aberration diagram at an image point of -75% of (A) is a lens arrangement | positioning figure which shows the infinity in-focus state of the wide-angle end of the zoom lens system which concerns on Embodiment 6 (Example 4), (b) concerns on Embodiment 6 (Example 4). A lens arrangement diagram showing an infinitely focused state at an intermediate position (intermediate focal length state) of the zoom lens system, (c) is an infinite distance at the telephoto end of the zoom lens system according to Embodiment 6 (Example 4). Lens layout showing the focus state (A) is a longitudinal aberration diagram in the infinitely focused state at the wide angle end of the zoom lens system according to Example 4, and (b) is an intermediate position (intermediate focal length state) of the zoom lens system according to Example 4. Longitudinal aberration diagram in the infinite focus state, (c) is a vertical aberration diagram in the infinite focus state at the telephoto end of the zoom lens system according to Example 4. FIG. (A) is a lateral aberration diagram at an image point of 75% of the maximum image height in a basic state where image blur correction at the telephoto end of the zoom lens system according to Example 4 is not performed; FIG. 6C is a lateral aberration diagram at an on-axis image point in a basic state where no image blur correction is performed at the telephoto end of the zoom lens system according to FIG. 9C, and FIG. 9C illustrates image blur correction at the telephoto end of the zoom lens system according to Example 4; FIG. 4D is a lateral aberration diagram at an image point of −75% of the maximum image height in the basic state where the zoom is not performed; FIG. The lateral aberration diagram at% image point, (e) is the lateral aberration diagram at the on-axis image point in the image blur correction state at the telephoto end of the zoom lens system according to Example 4, and (f) is in Example 4. Maximum image with image blur correction at the telephoto end of such a zoom lens system Lateral aberration diagram at an image point of -75% of (A) is a lens arrangement | positioning figure which shows the infinity in-focus state of the wide-angle end of the zoom lens system concerning Embodiment 7 (Example 5), (b) concerns on Embodiment 7 (Example 5). Lens arrangement diagram showing an infinitely focused state at an intermediate position (intermediate focal length state) of the zoom lens system, (c) is an infinite distance at the telephoto end of the zoom lens system according to Embodiment 7 (Example 5). Lens layout showing the focus state (A) is a longitudinal aberration diagram in the infinitely focused state at the wide angle end of the zoom lens system according to Example 5, and (b) is an intermediate position (intermediate focal length state) of the zoom lens system according to Example 5. Longitudinal aberration diagram in the infinite focus state, (c) is a longitudinal aberration diagram in the infinite focus state at the telephoto end of the zoom lens system according to Example 5. FIG. (A) is a lateral aberration diagram at an image point of 75% of the maximum image height in a basic state where image blur correction at the telephoto end of the zoom lens system according to Example 5 is not performed; (b) FIG. 6C is a lateral aberration diagram at an on-axis image point in a basic state where no image blur correction is performed at the telephoto end of the zoom lens system according to FIG. 10C, and FIG. 10C illustrates image blur correction at the telephoto end of the zoom lens system according to Example 5; FIG. 6D is a lateral aberration diagram at an image point of −75% of the maximum image height in the basic state where the zoom is not performed, and FIG. 7D is a graph showing 75 of the maximum image height in the image blur correction state at the telephoto end of the zoom lens system according to Example 5. The lateral aberration diagram at% image point, (e) is the lateral aberration diagram at the axial image point in the image blur correction state at the telephoto end of the zoom lens system according to Example 5, and (f) is in Example 5. Maximum image with image blur correction at the telephoto end of such a zoom lens system Lateral aberration diagram at an image point of -75% of

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Image pick-up element 3 Shutter button 4 1st lens group 5 Lens element 5a which has a reflective surface Reflective surface 6 Image side lens group AX1 Optical axis AX2 Optical axis G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group L1 1st lens element L2 2nd lens element L3 3rd lens element L4 4th lens element L5 Lens element L6 which has a reflective surface 6th lens element L7 7th lens element L8 8th lens element L9 9th Lens element L10 Tenth lens element A Aperture P Parallel plate S Image plane

Claims (35)

A zoom lens system having a plurality of lens groups each including at least one lens element,
An optical image of the object is formed so as to be continuously variable by changing the interval between at least any two of the lens groups,
Among the lens groups, the first lens group disposed on the most object side includes a lens element having a reflecting surface that bends light rays from the object,
A zoom lens system in which any one of the lens groups, any one of the lens elements, or a plurality of adjacent lens elements constituting one lens group move in a direction perpendicular to the optical axis.   Any one of the lens groups other than the first lens group, any one of the lens elements other than the lens element having a reflecting surface, or a plurality of adjacent lenses other than the lens elements having a reflecting surface constituting one lens group. The zoom lens system according to claim 1, wherein the lens element moves in a direction perpendicular to the optical axis.   2. The adjacent lens elements that constitute one of the lens groups or one lens group that moves in a direction perpendicular to the optical axis are configured by three lens elements. Zoom lens system.   The zoom lens system according to claim 1, wherein the reflecting surface bends the axial principal ray from the object by approximately 90 °.   The zoom lens system according to claim 1, wherein the lens element having a reflecting surface is a prism.   The zoom lens system according to claim 5, wherein the prism has optical power.   The zoom lens system according to claim 1, wherein the lens element having a reflecting surface is a mirror.   The first lens group includes, in order from the object side to the image side, a lens element having negative optical power, a lens element having a reflection surface, and at least one lens element, and having positive optical power. The zoom lens system according to claim 1, comprising a lens element. The zoom lens system according to claim 1, wherein the zoom lens system satisfies the following condition (1):
0.2 <P _W / Y _W × 10 ⁻³ <1.7 (1)
(However, Z = f _T / f _W > 2.5)
here,
P _W : Distance on the optical axis between the reflecting surface and the object side principal point of the lens group or lens element moving in the direction perpendicular to the optical axis at the wide angle end,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 1, satisfying the following condition (2):
0.4 <f ₁ / Y _W × 10 ⁻³ <1.5 (2)
(However, Z = f _T / f _W > 2.5)
here,
f ₁ : Composite focal length of the first lens group,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 1, wherein the zoom lens system satisfies the following condition (3):
0.1 <PF / Y _W × 10 ⁻³ <1.0 (3)
(However, Z = f _T / f _W > 2.5)
here,
PF: Distance on the optical axis from the most object side position on the optical axis of the lens element located closest to the object side to the most image side position on the optical axis of the lens element having a reflecting surface,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 1, satisfying the following condition (4):
1.0 <H _P / H _Y <6.0 (4)
here,
H _P : the thickness of the lens element having the reflecting surface in the optical axis direction,
H _Y : the thickness of the lens group or lens element moving in the direction perpendicular to the optical axis in the optical axis direction. The zoom lens system according to claim 1, satisfying the following condition (5):
0.3 <M _Y / H _P <0.6 (5)
here,
M _Y : The amount of movement in the optical axis direction of the lens group or lens element that moves in the direction perpendicular to the optical axis in zooming from the wide-angle end to the telephoto end,
H _P : Thickness in the optical axis direction of a lens element having a reflecting surface. The zoom lens system according to claim 1, satisfying the following condition (6):
0.1 <M _Y / Y _W × 10 ⁻³ <0.4 (6)
(However, Z = f _T / f _W > 2.5)
here,
M _Y : The amount of movement in the optical axis direction of the lens group or lens element that moves in the direction perpendicular to the optical axis in zooming from the wide-angle end to the telephoto end,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 1, satisfying the following condition (7):
6.0 <Y _W / I _V × 10 ³ <9.5 (7)
(However, Z = f _T / f _W > 2.5)
here,
Y _W : the amount of movement at the time of maximum blur correction of the lens group or lens element moving in the direction perpendicular to the optical axis at the focal length f _W of the entire system at the wide angle end,
I _V : Length of the image sensor in the short side direction I _V = 2 × f _W × tan ω _W × 0.60,
f _W : focal length of the entire system at the wide-angle end,
ω _W is the incident half angle of view at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 1, satisfying the following condition (8):
3.0 <P _W / I _V <11.0 (8)
(However, Z = f _T / f _W > 2.5)
here,
P _W : Distance on the optical axis between the reflecting surface and the object side principal point of the lens group or lens element moving in the direction perpendicular to the optical axis at the wide angle end,
I _V : Length of the image sensor in the short side direction I _V = 2 × f _W × tan ω _W × 0.60,
f _W : focal length of the entire system at the wide-angle end,
ω _W is the incident half angle of view at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 1, satisfying the following condition (9):
0.2 <f _W / H _P <0.9 (9)
(However, Z = f _T / f _W > 2.5)
here,
H _P : the thickness of the lens element having the reflecting surface in the optical axis direction,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 1, wherein the zoom lens system satisfies the following condition (10):
2.5 <H _P / I _V <5.0 (10)
(However, Z = f _T / f _W > 2.5)
here,
H _P : the thickness of the lens element having the reflecting surface in the optical axis direction,
I _V : Length of the image sensor in the short side direction I _V = 2 × f _W × tan ω _W × 0.60,
f _W : focal length of the entire system at the wide-angle end,
ω _W is the incident half angle of view at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.   The zoom lens system according to claim 1, comprising four lens groups.   The zoom lens system according to claim 19, wherein the first lens unit does not move in the optical axis direction during zooming from the wide-angle end to the telephoto end during imaging.   The zoom lens system according to claim 19, wherein the entire third lens group moves in a direction perpendicular to the optical axis.   The zoom lens system according to claim 19, wherein some lens elements constituting the third lens group move in a direction perpendicular to the optical axis.   20. A first lens group having positive optical power, a second lens group having negative optical power, and a subsequent lens group including at least one lens group having positive optical power. The zoom lens system described in 1.   The zoom lens according to claim 23, wherein the subsequent lens group includes a third lens group having a positive optical power and a fourth lens group having a positive optical power in order from the object side to the image side. system. The zoom lens system according to claim 24, wherein the following condition (11) is satisfied:
0.5 <− (1-m _2T ) × m _3T × m _4T <2.0 (11)
(However, Z = f _T / f _W > 2.5)
here,
m _2T : magnification of the second lens unit at the telephoto end when the shooting distance is ∞,
m _3T : magnification of the third lens unit at the telephoto end when the shooting distance is ∞,
m _4T : Magnification of the fourth lens unit at the telephoto end when the shooting distance is ∞,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 24, wherein the following condition (12) is satisfied:
1.5 <f ₁ / f ₃ <3.5 (12)
(However, Z = f _T / f _W > 2.5)
here,
f ₁ : Composite focal length of the first lens group,
f ₃ : composite focal length of the third lens group,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end. The zoom lens system according to claim 24, wherein the following condition (13) is satisfied:
1.0 <−f ₁ / f ₂ <4.0 (13)
(However, Z = f _T / f _W > 2.5)
here,
f ₁ : Composite focal length of the first lens group,
f ₂ : composite focal length of the second lens group,
f _W : focal length of the entire system at the wide-angle end,
f _T is the focal length of the entire system at the telephoto end.   The zoom lens system according to claim 1, comprising three lens groups.   The zoom lens system according to claim 28, wherein the first lens unit does not move in the optical axis direction during zooming from the wide-angle end to the telephoto end during imaging.   The zoom lens system according to claim 28, wherein the entire second lens group moves in a direction perpendicular to the optical axis.   The zoom lens system according to claim 28, wherein some of the lens elements constituting the second lens group move in a direction perpendicular to the optical axis.   The zoom lens system according to claim 28, comprising a first lens group having negative optical power and a subsequent lens group including at least one lens group having positive optical power.   The zoom lens according to claim 32, wherein the succeeding lens group includes a second lens group having a positive optical power and a third lens group having a positive optical power in order from the object side to the image side. system. An imaging apparatus capable of outputting an optical image of an object as an electrical image signal,
A zoom lens system that forms an optical image of the object;
An image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
A plurality of lens groups each including at least one lens element;
An optical image of the object is formed so as to be continuously variable by changing the interval between at least any two of the lens groups,
Among the lens groups, the first lens group disposed on the most object side includes a lens element having a reflecting surface that bends light rays from the object,
Any one of the lens groups, any one of the lens elements, or a plurality of adjacent lens elements constituting one lens group move in a direction perpendicular to the optical axis.
Imaging device. A camera that converts an optical image of an object into an electrical image signal, and displays and stores the converted image signal;
An image pickup apparatus including a zoom lens system that forms an optical image of an object, and an image sensor that converts an optical image formed by the zoom lens system into an electrical image signal;
The zoom lens system is
A plurality of lens groups each including at least one lens element;
An optical image of the object is formed so as to be continuously variable by changing the interval between at least any two of the lens groups,
Among the lens groups, the first lens group disposed on the most object side includes a lens element having a reflecting surface that bends light rays from the object,
Any one of the lens groups, any one of the lens elements, or a plurality of adjacent lens elements constituting one lens group move in a direction perpendicular to the optical axis.
camera.

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