Telephoto zoom lens system and electronic apparatus including the same

Provided are a telephoto zoom lens system and an electronic apparatus including the telephoto zoom lens system. The telephoto zoom lens system includes a first lens group having a positive refractive power and is fixed when zooming and focusing, a second lens group having a negative refractive power, a third lens group having a negative refractive power and performs focusing, a fourth lens group having a positive refractive power, and a rear lens group comprising one or more lens groups located between the fourth lens group and an image side. At least one lens group of the rear lens group is fixed while zooming, and a focal length thereof is unchanged while zooming.

RELATED APPLICATIONS

This application claims the priority benefit of Korean Patent Application No. 10-2013-0026308, filed on Mar. 12, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

One or more embodiments of the invention relate to a telephoto zoom lens system capable of quickly focusing by reducing the weight of a focusing lens group and an electronic apparatus including the zoom lens system.

2. Description of the Related Art

In the case of photographing apparatuses using solid state imaging devices, such as digital cameras, interchangeable lens systems, and video cameras, there is user demand for high resolution and high magnification. Also, since photographing apparatuses using solid imaging devices are suitable for being miniaturized, they have recently been applied to small information terminals as well as to cellular phones. Also, users now possess more specialized knowledge with respect to photographing apparatuses, and large-aperture telephoto zoom lens systems have been increasingly developed based on such market demands. Large-aperture telephoto zoom lens systems generally use a lens group located immediately after a first lens group as a focusing lens group. However, since an aperture of a first lens is large, a rear lens group of the first lens group also has a large aperture, such that a weight of the focusing lens group increases. When the weight of the focusing lens group is heavy, rapid movement of the focusing lens may be impeded.

SUMMARY

One or more embodiments of the invention include a telephoto zoom lens system capable of quickly focusing by reducing the weight of a focusing lens group.

One or more embodiments of the invention include an electronic apparatus including a telephoto zoom lens system capable of quickly focusing by reducing the weight of a focusing lens group.

Additional aspects will be set forth in the description which follows and, will become apparent from the description, or may be learned by practice of the presented embodiments.

According to one or more embodiments, a telephoto zoom lens system includes a first lens group having a positive refractive power and is fixed while zooming and focusing, a second lens group having a negative refractive power, a third lens group having a negative refractive power and performs focusing, a fourth lens group having a positive refractive power, and a rear lens group including one or more lens groups located between the fourth lens group and an image side. At least one lens group of the rear lens group is fixed while zooming, and a focal length thereof is unchanged while zooming.

One of the lens groups included in the rear lens group may include an aperture stop.

A size of an aperture of the aperture stop may be maintained to be uniform while zooming.

A distance between the second lens group and the third lens group may be unchanged while zooming.

The third lens group may include a lens that satisfies the following Equation:

-5.0≤RrearRfront≤0.0,
wherein Rfrontdenotes the radius of curvature of an object side surface of the lens of the third lens group, Rreardenotes the radius of curvature of an image side surface of the lens of the third lens group.

The third lens group may satisfy the following Equation:
1.4≦(1−mfocus,W2)·mrear,W2≦2.5,
wherein mfocus,W2denotes a magnification of the third lens group at a wide-angle position, and rear mrear,W2denotes a total magnification of lens groups located at the image side of the third lens group at the wide-angle position.

The third lens group may satisfy the following Equation:

0.7≤(1-mfocus,T2)·mrear,T2(1-mfocus,W2)·mrear,W2≤1.2,
wherein mfocus,W2denotes a magnification of the third lens group at the wide-angle position, mrear,W2denotes a total magnification of the lens groups located at the image side of the third lens group at the wide-angle position, mfocus,T2denotes a magnification of the third lens group at a telephoto position, and mrear,T2denotes a total magnification of the lens groups located at the image side of the third lens group at the telephoto position.

The rear lens group may include a lens group for image stabilization.

The lens group for image stabilization may have a negative refractive power.

The rear lens group may have a positive refractive power and may include a fifth lens group that is fixed while zooming.

The second lens group, the third lens group, and the fourth lens group may move while zooming.

While zooming, the second lens group, the third lens group, and the fourth lens group may move from an object side to the image side with no inflection point.

The rear lens group may include a fifth lens group having a positive refractive power and moves while zooming, and a sixth lens group provided between the fifth lens group and the image side and includes a first sub lens group having a negative refractive power and a second sub lens group having a positive refractive power.

The second lens group, the third lens group, the fourth lens group, and the fifth lens group may move while zooming.

While zooming, the second lens group, the third lens group, the fourth lens group, and the fifth lens group may move from the object side to the image side with no inflection point.

The first sub lens group may perform image stabilization.

The third lens group may include one lens.

The third lens group may include a lens selected from the group consisting of a biconcave lens or a plano-concave lens.

According to one or more embodiments, an electronic apparatus includes a telephoto zoom lens system and an imaging device that receives light from the telephoto zoom lens system. In this case, the telephoto zoom lens system includes a first lens group having a positive refractive power and is fixed while zooming and focusing, a second lens group having a negative refractive power, a third lens group having a negative refractive power and performs focusing, a fourth lens group having a positive refractive power, and a rear lens group including one or more lens groups located between the fourth lens group and an image side. At least one lens group of the rear lens group is fixed while zooming, and a focal length thereof is unchanged while zooming.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the invention will now be described in detail with reference to the attached drawings.

FIG. 1is a diagram illustrating a telephoto zoom lens system100-1, according to an embodiment. The telephoto zoom lens system100-1may include a first lens group G1having a positive refractive power, a second lens group G2having a negative refractive power, a third lens group G3having a negative refractive power, a fourth lens group G4having a positive refractive power, and a rear lens group including one or more lens groups located at an image side I of the fourth lens group G4, which are sequentially arranged from an object side O to the image side I.

The first lens group G1may be fixed while zooming and focusing. Accordingly, in the case of the telephoto zoom lens system100-1, while zooming, a distance between an object side surface of a lens closest to the object side O of the first lens group G1and an image plane (in other words, a full length thereof), is not changed. In this case, the image plane may designate an imaging device or a photographing plane.

The third lens group G3may perform focusing. The third lens group G3may include, for example, two lenses or less so as to be more light-weight. As described above, the third lens group for focusing is lightened, thereby facilitating quick focusing. Also, a focusing lens group may be arranged at a location where a lens aperture is small. When the first lens group G1has a positive refractive power, a lens group near the second lens group G2would have a relatively small aperture, e.g., the third lens group G3as a focusing lens group. Since an aperture of the third lens group G3is small, it is possible to lighten a weight of the focusing lens group. The third lens group G3, which is the focusing lens group, is lightened, thereby reducing a weight of a driving unit driving the third lens group G3. For example, the third lens group G3may include, for example, one lens so as to be more light-weight. The third lens group G3may include one of a biconcave lens and a plano-concave lens.

One or more lens groups of the rear lens group may be fixed while zooming. Also, since performance of the telephoto zoom lens system100-1greatly varies with hand shake, the telephoto zoom lens system100-1may include an image stabilization lens group. For example, the rear lens group may include a lens group for image stabilization. The lens group for image stabilization may be fixed and not move while zooming and/or focusing. Accordingly, a configuration of a driver for moving the lens group for image stabilization may be simplified, and an electronic apparatus having capability for capturing images and photographing (e.g., a photographing apparatus) may be miniaturized due to the simplified configuration of the driver. Also, a driving load on an image stabilization lens group is reduced in such a way that power consumption may be reduced, and a degree of freedom may increase when employing a driving source.

On the other hand, when zooming, the first lens group G1is fixed and the second lens group G2, the third lens group G3, and the fourth lens group G4may move. For example, while zooming, a distance between the second lens group G2and the third lens group G3may be uniform. When the distance between the third lens group G3and the second lens group G2is maintained to be uniform while zooming, this condition may be favorable when configuring a driving unit for zooming.

On the other hand, some groups of the rear lens group may move while zooming. However, the image stabilization lens group included in the rear lens group may be fixed while zooming.

The fourth lens group G4may correct field curvature.

An example of a configuration of the rear lens group will now be described. Referring toFIGS. 1, 5, 9, and 13, the rear lens group may include a fifth lens group G5having a positive refractive power. The fifth lens group G5may be fixed while zooming. The fifth lens group G5may include a first sub lens group G5-1, a second sub lens group G5-2for image stabilization, and a third sub lens group G5-3. For example, the first sub lens group G5-1may have a positive refractive power, the second sub lens group G5-2may have a negative refractive power, and the third sub lens group G5-3may have a positive refractive power. The fifth lens group G5may include an aperture stop ST at its object side O.

Referring toFIG. 17, the rear lens group may include the fifth lens group G5, and a sixth lens group G6including a first sub lens group G6-1and a second sub lens group G6-2. The first sub lens group G6-1may perform image stabilization. The fifth lens group G5may move while zooming, and the sixth lens group G6may be fixed while zooming. The fifth lens group G5may include an aperture stop ST at its object side O.

To lighten the weight of the image stabilization lens group, an aperture of the image stabilization lens group may be reduced in size. To reduce the size of the aperture of the image stabilization lens group, for example, a focal length of a lens group located just before the image stabilization lens group may be reduced. When the lens group located just before the image stabilization lens group has a positive refractive power, the aperture becomes smaller, thereby lightening the weight of the image stabilization lens group. For example, inFIGS. 1, 5, 9, and 13, the first sub lens group G5-1, which is located just before the second sub lens group G5-2(the image stabilization lens group), may have a positive refractive power. InFIG. 17, the fifth lens group G5, which is located just before the first sub lens group G6-1(the image stabilization lens group), may have a positive refractive power.

The telephoto zoom lens system according to the present embodiment may not change the aperture while zooming. That is, the telephoto zoom lens system is a bright zoom lens whose F number Fno is fixed while zooming.

On the other hand, in the case of the telephoto zoom lens system according to the present embodiment, while zooming from the wide-angle position to the telephoto position, the second lens group G2and the third lens group G3may monotonically move from the object side O to the image side I. That is, the second group G2and the third lens group G3may simply move with no inflection point while zooming. The fourth lens group G4may simply move from the object side O to the image side I while zooming. Otherwise, the fourth lens group G4may move from the object side O toward the image side I while zooming from the wide-angle position to a random middle position, and may move further toward the image side I while zooming to the telephoto position. That is, the fourth lens group G4may have an inflection point while zooming. When a lens group, which moves while zooming, has a trajectory that simply increases or simply decreases with no inflection point, it is convenient to control zooming. When there is an inflection point, it is convenient to correct optical performance. For example, all lens groups that move while zooming move from the object side O to the image side I, and since zooming is easily performed, it is possible to increase added values of the products.

The third lens group G3may satisfy the following equation.

-5.0≤RrearRfront≤0.0Equation⁢⁢(1)
In this case, Rfrontdenotes the radius of curvature of a lens surface in the third lens group G3closest to the object side O, and Rreardenotes the radius of curvature of a lens surface in the third lens group G3closest to the image side I.

Equation 1 defines shapes of lenses included in the third lens group G3. For example, the third lens group G3may include one of a biconcave lens and a plano-concave lens. Since the second lens group G2has a negative refractive power, a light ray diverges from the second lens group G2. When the third lens group G3includes a biconcave lens or a plano-concave lens, it is easy to correct aberrations and it is possible to properly arrange refractive powers of lenses included in the second lens group G2.

Also, the third lens group G3may satisfy the following equation.
1.4≦(1−mfocus,W2)·mrear,W2≦2.5  Equation (2)
In this case, mfocus,Wdenotes a magnification of the third lens group G3at the wide-angle position, and mrear,Wdenotes a total magnification of lens groups located after the third lens group G3(i.e., located on the image side of the third lens group G3) at the wide-angle position.

Equation 2 defines a change of a back focal length according to a unit movement of the third lens group G3in a longitudinal direction, which may show longitudinal sensitivity of the third lens group G3. When the longitudinal sensitivity is excessively high, since the back focal length is greatly changed according to a position of the third lens group G3, a variance of optical performances according thereto also increases. On the contrary, when the longitudinal sensitivity is excessively low, it is difficult to provide the shortest photographic distance. When satisfying Equation 2, it is possible to provide the appropriate shortest photographic distance and to reduce a variance in performance according to the position of the third lens group G3, which is the focusing lens group.

The third lens group G3may satisfy the following equation.

0.7≤(1-mfocus,T2)·mrear,T2(1-mfocus,W2)·mrear,W2≤1.2Equation⁢⁢(3)
In this case, mfocus,Wdenotes a magnification of the third lens group G3at the wide-angle position, mrear,Wdenotes a total magnification of the lens groups located after the third lens group G3(i.e., located on the image side of the third lens group 3) at the wide-angle position, mfocus,Tdenotes a magnification of the third lens group G3at the telephoto position, and mrear,Tdenotes a total magnification of the lens groups located after the third lens group G3at the telephoto position.

Equation 3 shows a longitudinal sensitivity ratio of the third lens group G3at the wide-angle position and the telephoto position. When the longitudinal sensitivity ratio of the third lens group G3satisfies Equation 3, a variance amount of the back focal length according to the movement of the third lens group G3decreases regardless of zooming, and thus it is possible to easily control auto focusing.

Hereinafter, design data of the telephoto zoom lens system according to the present embodiment will be described. Hereinafter, f is an overall focal length of the zoom lens system and uses mm as a unit, Fno denotes an F number, 2ω is an angle of view and uses degree as a unit, R denotes the radius of curvature, Dn denotes a distance between lenses or a thickness of a lens, Nd denotes a refractive index, vd denotes an Abbe number, ST denotes an aperture stop, obj denotes an object plane, and img denotes an image plane or an imaging plane, respectively. In the drawings illustrating the respective embodiments, one or more filters OF may be provided at the position closest to the image side I.

FIG. 1illustrates the telephoto zoom lens system100-1at the wide-angle position, the middle position, and the telephoto position, respectively, according to an embodiment. Design data thereof will now be described as follows. InFIG. 1, reference numerals of respective lenses are partially shown. In the drawings hereafter, only some reference numerals of lenses are shown.

In the present embodiment, when zooming, variable distances Dn, focal lengths, angles of view, F numbers, and overall lengths with respect to infinite object distances (infinity) and object distances of 821 mm at the wide-angle position, the middle position, and the telephoto position are shown, respectively, as follows.

FIGS. 2A to 2Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-1at the wide-angle position.FIG. 2Aillustrates a case in which second sub lens group G5-2, which is an image stabilization lens group, moves vertically upward by 0.24 mm with respect to an optical axis.FIG. 2Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 2Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.24 mm with respect to the optical axis.

FIGS. 3A to 3Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-1at the middle position.FIG. 3Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.34 mm with respect to the optical axis.FIG. 3Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 3Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.34 mm with respect to the optical axis.

FIGS. 4A to 4Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-1at the telephoto position.FIG. 4Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.66 mm with respect to the optical axis.FIG. 4Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 4Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.66 mm with respect to the optical axis, respectively.

FIG. 5illustrates a telephoto zoom lens system100-2at a wide-angle position, a middle position, and a telephoto position, respectively, according to another embodiment. Design data thereof will now be described as follows.

In the present embodiment, when zooming, variable distances Dn, focal lengths, angles of view, F numbers, and overall lengths with respect to infinite object distances (infinity) and object distances of 820 mm at the wide-angle position, the middle position, and the telephoto position are shown, respectively, as follows.

FIGS. 6A to 6Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-2at the wide-angle position.FIG. 6Aillustrates a case in which a second sub lens group G5-2, which is an image stabilization lens group, moves vertically upward by 0.21 mm with respect to an optical axis.FIG. 6Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 6Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.21 mm with respect to the optical axis.

FIGS. 7A to 7Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-2at the middle position.FIG. 7Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.31 mm with respect to the optical axis.FIG. 7Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 7Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.31 mm with respect to the optical axis.

FIGS. 8A to 8Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-2at the telephoto position.FIG. 8Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.59 mm with respect to the optical axis.FIG. 8Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 8Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.59 mm with respect to the optical axis.

FIG. 9illustrates a telephoto zoom lens system100-3at a wide-angle position, a middle position, and a telephoto position, respectively, according to another embodiment. Design data thereof will now be described as follows.

In the present embodiment, when zooming, variable distances Dn, focal lengths, angles of view, F numbers, and overall lengths with respect to infinite object distances (infinity) and object distances of 820 mm at the wide-angle position, the middle position, and the telephoto position are shown, respectively, as follows.

FIGS. 10A to 10Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-3at the wide-angle position.FIG. 10Aillustrates a case in which a second sub lens group G5-2, which is an image stabilization lens group, moves vertically upward by 0.23 mm with respect to an optical axis.FIG. 10Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 10Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.23 mm with respect to the optical axis.

FIGS. 11A to 11Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-3at the middle position.FIG. 11Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.33 mm with respect to the optical axis.FIG. 11Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 11Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.33 mm with respect to the optical axis.

FIGS. 12A to 12Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-3at the telephoto position.FIG. 12Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.63 mm with respect to the optical axis.FIG. 12Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 12Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.63 mm with respect to the optical axis.

FIG. 13illustrates a telephoto zoom lens system100-4at a wide-angle position, a middle position, and a telephoto position, respectively, according to another embodiment. Design data thereof will now be described as follows.

In the present embodiment, when zooming, variable distances Dn, focal lengths, angles of view, F numbers, and overall lengths with respect to infinite object distances (infinity) and object distances of 822 mm at the wide-angle position, the middle position, and the telephoto position are shown, respectively, as follows.

FIGS. 14A to 14Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-4at the wide-angle position.FIG. 14Aillustrates a case in which a second sub lens group G5-2, which is an image stabilization lens group, moves vertically upward by 0.24 mm with respect to an optical axis.FIG. 14Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 14Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.24 mm with respect to the optical axis.

FIGS. 15A to 15Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-4at the middle position.FIG. 15Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.35 mm with respect to the optical axis.FIG. 15Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 15Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.35 mm with respect to the optical axis.

FIGS. 16A to 16Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-4at the telephoto position.FIG. 16Aillustrates a case in which the second sub lens group G5-2moves vertically upward by 0.66 mm with respect to the optical axis.FIG. 16Billustrates a case in which the second sub lens group G5-2is located on the optical axis.FIG. 16Cillustrates a case in which the second sub lens group G5-2moves vertically downward by 0.66 mm with respect to the optical axis.

FIG. 17illustrates a telephoto zoom lens system100-5at a wide-angle position, a middle position, and a telephoto position, respectively, according to another embodiment. Design data thereof will now be described as follows.

In the present embodiment, when zooming, variable distances Dn, focal lengths, angles of view, F numbers, and overall lengths with respect to an infinite object distance and an object distance of 823 mm at the wide-angle position, the middle position, and the telephoto position are shown, respectively, as follows.

FIGS. 18A to 18Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-5at the wide-angle position.FIG. 18Aillustrates a case in which a first sub lens group G6-1, which is an image stabilization lens group, moves vertically upward by 0.23 mm with respect to the optical axis.FIG. 18Billustrates a case in which the first sub lens group G6-1is located on the optical axis.FIG. 18Cillustrates a case in which the first sub lens group G6-1moves vertically downward by 0.23 mm with respect to the optical axis.

FIGS. 19A to 19Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-5at the middle position.FIG. 19Aillustrates a case in which the first sub lens group G6-1moves vertically upward by 0.33 mm with respect to the optical axis.FIG. 19Billustrates a case in which the first sub lens group G6-1is located on the optical axis.FIG. 19Cillustrates a case in which the first sub lens group G6-1moves vertically downward by 0.33 mm with respect to the optical axis.

FIGS. 20A to 20Care diagrams illustrating lateral aberration of the telephoto zoom lens system100-5at the telephoto position.FIG. 20Aillustrates a case in which the first sub lens group G6-1moves vertically upward by 0.63 mm with respect to the optical axis.FIG. 20Billustrates a case in which the first sub lens group G6-1is located on the optical axis.FIG. 20Cillustrates a case in which the first sub lens group G6-1moves vertically downward by 0.63 mm with respect to the optical axis.

Movement amounts of the image stabilization lens groups according to the angles of view in the respective embodiments are shown as follows.

On the other hand, apertures of the aperture stops ST in the telephoto zoom lens systems100-1,100-2,100-3,100-4, and100-5are uniform regardless of focal lengths. Radii of the aperture stops ST are 13.4 mm, 14.4 mm, 13.5 mm, 13.5 mm, and 13.9 mm in the telephoto zoom lens systems100-1,100-2,100-3,100-4, and100-5, respectively, and the sizes of the apertures of the aperture stops of the telephoto zoom lens systems100-1,100-2,100-3,100-4, and100-5are not changed while zooming.

The telephoto zoom lens systems according to the embodiments of the invention may be applied to electronic apparatuses using imaging devices such as photographing apparatuses, interchangeable lens cameras, digital cameras, and camcorders.

FIG. 21is a view illustrating a photographing apparatus including a telephoto zoom lens system100, according to an embodiment. The telephoto zoom lens system100may include the telephoto zoom lens systems100-1,100-2,100-3,100-4, and100-5, which are described above. Also, the photographing apparatus includes a housing110, and an imaging device112disposed in the housing110and receives light from the telephoto zoom lens system100. The photographing apparatus may include a recording unit113(e.g., memory) disposed in the housing110and in which information corresponding to an image of an object photo-electrically converted by the imaging device112is recorded. The photographing apparatus may include a view finder114for observing the image of the object. Also, a display unit115displaying the image of the object may be included. In this case, the view finder114and the display unit115are provided separately, but in other embodiments, only a display unit may be included with no additional view finder. The photographing apparatus shown inFIG. 21is just an example and not limited thereto and may be applied to various optical and electronic devices in addition to cameras. As described above, it is possible to create optical and electronic devices capable of performing automatically focusing quickly by applying the telephoto zoom lens systems according to the embodiments of the invention to electronic apparatuses such as digital cameras.

The telephoto zoom lens systems according to the embodiments of the invention may be miniaturized by using an inner zoom method. Also, since the telephoto zoom lens system has a long focal length and a smaller angle of view, there are more effects due to hand shake. However, it is possible to prevent deterioration of performance due to the hand shake by including an image stabilization lens group. Also, the image stabilization lens group does not move while zooming, thereby simplifying a configuration of a driver for moving the image stabilization lens group.

The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. Numerous modifications and adaptations will be readily apparent to those of ordinary skill in this art without departing from the spirit and scope of the invention as defined by the following claims. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the following claims, and all differences within the scope will be construed as being included in the invention.

No item or component is essential to the practice of the invention unless the element is specifically described as “essential” or “critical”. It will also be recognized that the terms “comprises,” “comprising,” “includes,” “including,” “has,” and “having,” as used herein, are specifically intended to be read as open-ended terms of art. The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless the context clearly indicates otherwise. In addition, it should be understood that although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms, which are only used to distinguish one element from another. Furthermore, recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.