JP2016139125A - Zoom lens system, interchangeable lens device, and camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact zoom lens system, an interchangeable lens device, and a camera system, while maintaining optical performance.SOLUTION: A zoom lens system includes, in order from an object side to an image side, a first focus lens group having negative power and a second focus lens group having positive power. The first focus lens group and the second focus lens group move along an optical axis when zooming from a wide angle end to a telephoto end. The first focus lens group and the second focus lens group move to perform focusing, during focusing from an infinity focusing state to a proximity object focusing state, to satisfy a predetermined condition.SELECTED DRAWING: Figure 1A

Description

  The present disclosure relates to a zoom lens system, an interchangeable lens apparatus, and a camera system.

  Patent Document 1 discloses a zoom lens system that is composed of positive, negative, positive and rear groups, and focuses with two focusing groups having negative and positive powers in the rear group.

  Patent Document 2 discloses a zoom lens system that is composed of positive and negative + rear groups, and focuses on two focusing groups having negative and positive powers in the rear group.

  Patent Document 3 discloses a zoom lens system that includes a positive / negative + rear group, and the rear group includes a focusing group.

JP 2013-105131 A JP 2014-157225 A JP 2014-186306 A

  It is an object to provide a compact zoom lens system, an interchangeable lens device including a zoom lens system, and a camera system while maintaining optical performance.

  The zoom lens system according to the present disclosure is a zoom lens system including a plurality of lens groups each including at least one lens element, and the first focus lens group having negative power in order from the object side to the image plane side. And a second focus lens group having positive power, and the first focus lens group and the second focus lens group move along the optical axis at the time of zooming from the wide-angle end to the telephoto end. During focusing from the in-focus state to the close-in-object in-focus state, the first focus lens group and the second focus lens group move to perform focusing, and the following conditional expressions (1) and (2) are satisfied.

−20 <β1t / β1w × β2t / β2w <20 (1)
0.25 <| f1 / f2 | <1.30 (2)
here,
β1t: lateral magnification at the telephoto end of the first focus lens group β1w: lateral magnification at the wide-angle end of the first focus lens group β2t: lateral magnification at the telephoto end of the second focus lens group β2w: of the second focus lens group Horizontal magnification f1 at the wide-angle end: focal length f2 of the first focus lens group: focal length of the second focus lens group.

  An interchangeable lens device according to the present disclosure is a zoom lens system including a plurality of lens groups each including at least one lens element, and includes a first focus lens group having negative power in order from the object side to the image plane side. And a second focus lens group having a positive power, and the first focus lens group and the second focus lens group move along the optical axis at the time of zooming from the wide angle end to the telephoto end, and focusing at infinity Zoom lens system satisfying the following conditional expressions (1) and (2) by performing focusing by moving the first focus lens group and the second focus lens group during focusing from the state to the in-focus state of the close object And a lens mount that can be connected to a camera body including an image sensor that receives an optical image formed by the zoom lens system and converts it into an electrical image signal.

−20 <β1t / β1w × β2t / β2w <20 (1)
0.25 <| f1 / f2 | <1.30 (2)
A camera system according to the present disclosure is a zoom lens system including a plurality of lens groups each including at least one lens element, and includes a first focus lens group having negative power in order from the object side to the image plane side; A second focus lens group having a positive power, and the first focus lens group and the second focus lens group move along the optical axis at the time of zooming from the wide-angle end to the telephoto end, and are in focus at infinity A zoom lens system that satisfies the following conditional expressions (1) and (2) by performing focusing by moving the first focus lens group and the second focus lens group during focusing from 1 to An interchangeable lens apparatus including the interchangeable lens apparatus and a camera mount that is detachably connected to the interchangeable lens apparatus to receive an optical image formed by the zoom lens system and convert it into an electrical image signal. And a camera body including an element.

−20 <β1t / β1w × β2t / β2w <20 (1)
0.25 <| f1 / f2 | <1.30 (2)

  The present disclosure can realize a small zoom lens system, an interchangeable lens apparatus including the zoom lens system, and a camera system while maintaining optical performance.

Lens arrangement diagram showing an infinitely focused state of the zoom lens system according to Embodiment 1 (Numerical Example 1) In FIG. 1A, the lens arrangement in the state of B In FIG. 1A, the lens arrangement in the state of C Longitudinal aberration diagram of the zoom lens system according to Numerical Example 1 in an infinitely focused state Longitudinal aberration diagram of the zoom lens system according to Numerical Example 1 in the close object focusing state Lateral aberration diagrams in the basic state where image blur correction is not performed and in the image blur correction state at the telephoto end of the zoom lens system according to Numerical Example 1 Lens arrangement diagram showing an infinitely focused state of the zoom lens system according to Embodiment 2 (Numerical Example 2) In FIG. 5A, the lens arrangement in the state of B In FIG. 5A, the lens arrangement in the state of C Longitudinal aberration diagram of the zoom lens system according to Numerical Example 2 in a focused state at infinity Longitudinal aberration diagram of a zoom lens system according to Numerical Example 2 in a close object focusing state Lateral aberration diagrams in the basic state where image blur correction is not performed and in the image blur correction state at the telephoto end of the zoom lens system according to Numerical Example 2 Lens arrangement diagram showing an infinitely focused state of a zoom lens system according to Embodiment 3 (Numerical Example 3) In FIG. 9A, the lens arrangement in the state of B In FIG. 9A, the lens arrangement in the state of C Longitudinal aberration diagram of the zoom lens system according to Numerical Example 3 in an infinitely focused state Longitudinal aberration diagram of a zoom lens system according to Numerical Example 3 in a close object focusing state Lateral aberration diagrams in the basic state where image blur correction is not performed and in the image blur correction state at the telephoto end of the zoom lens system according to Numerical Example 3 Lens arrangement diagram showing an infinitely focused state of a zoom lens system according to Embodiment 4 (Numerical Example 4) In FIG. 13A, the lens arrangement in the state of B In FIG. 13A, the lens arrangement in the state of C Longitudinal aberration diagram of the zoom lens system according to Numerical Example 4 in a focused state at infinity Longitudinal aberration diagram of close-up object focusing state of zoom lens system according to Numerical Example 4 Horizontal aberration diagram in the basic state where image blur correction is not performed and in the image blur correction state at the telephoto end of the zoom lens system according to Numerical Example 4 Lens arrangement diagram showing an infinitely focused state of a zoom lens system according to Embodiment 5 (Numerical Example 5) In FIG. 17A, the lens arrangement in the state of B In FIG. 17A, the lens arrangement in the state of C Longitudinal aberration diagram of the zoom lens system according to Numerical Example 5 in an infinitely focused state Longitudinal aberration diagram of close-up object focusing state of zoom lens system according to Numerical Example 5 Lens arrangement diagram showing an infinitely focused state of a zoom lens system according to Embodiment 6 (Numerical Example 6) In FIG. 20A, the lens arrangement in the state of B In FIG. 20A, the lens arrangement in the state of C Longitudinal aberration diagram of the zoom lens system according to Numerical Example 6 in a focused state at infinity Longitudinal aberration diagram of a zoom lens system according to Numerical Example 6 in a close object focusing state Lens arrangement diagram showing an infinitely focused state of a zoom lens system according to Embodiment 7 (Numerical Example 7) In FIG. 23A, the lens arrangement in the state of B In FIG. 23A, the lens arrangement in the state of C Longitudinal aberration diagram of the zoom lens system according to Embodiment 7 in an infinitely focused state Longitudinal aberration diagram of close-up object focusing state of zoom lens system according to Embodiment 7 Lateral aberration diagrams in the basic state where image blur correction is not performed and in the image blur correction state at the telephoto end of the zoom lens system according to Embodiment 7 Schematic configuration diagram of an interchangeable lens digital camera system according to Embodiment 8

(Embodiments 1 to 7)
[1. Constitution]
1A to 1C, FIGS. 5A to 5C, FIGS. 9A to 9C, FIGS. 13A to 13C, FIGS. 17A to 17C, FIGS. 20A to 20C, and FIGS. FIG. 8 is a lens arrangement diagram illustrating an infinitely focused state of the zoom lens system according to ˜7. In each lens arrangement diagram, FIGS. 1A, 5A, 9A, 13A, 17A, 20A, and 23A are lens arrangement diagrams at the wide-angle end. FIGS. 1B, 5B, 9B, 13B, 17B, 20B, and 23B are lens arrangement diagrams at intermediate positions. 1C, 5C, 9C, 13C, 17C, 20C, and 23C are lens arrangement diagrams at the telephoto end.

  The wide-angle end indicates the shortest focal length state. The focal length in the shortest focal length state is fW. The intermediate position refers to an intermediate focal length state. The focal length fm in the intermediate focal length state is defined by the following formula [Equation 1].

  The telephoto end refers to the longest focal length state. The focal length in the longest focal length state is fT. In each lens layout shown in FIGS. 1A, 5A, 9A, 13A, 17A, 20A, and 23A, the broken line arrows shown in the drawings are the wide-angle end and the intermediate position in order from the top. , And obtained by connecting the positions of the lens groups in each state at the telephoto end. The wide-angle end and the intermediate position, and the intermediate position and the telephoto end are simply connected by a straight line, which is different from the actual movement of each lens group.

  Furthermore, in each figure, the arrow attached to the lens group represents the focusing from the infinite focus state to the close object focus state. 1A, FIG. 5A, FIG. 9A, FIG. 13A, FIG. 17A, FIG. 20A, and FIG. 23A, reference numerals are described for each lens group, and for convenience, an arrow indicating focusing is provided below the reference numerals of each lens group. It is attached. In each zooming state, the direction in which each lens group moves during focusing will be described in detail later for each embodiment.

  In FIG. 13A, FIG. 17A, and FIG. 20A, an asterisk (*) attached by drawing a line from a circle on a specific surface indicates that the surface with the circle is an aspherical surface. Yes. In each figure, a symbol (+) and a symbol (−) attached to a symbol of each lens group correspond to a power symbol of each lens group. In each figure, the straight line described on the rightmost side represents the position of the image plane S.

<Embodiment 1>
As shown in FIGS. 1A, 1B, and 1C, in the zoom lens system according to Embodiment 1, the first lens group G1 includes a negative meniscus having a convex surface directed toward the object side in order from the object side to the image surface side. A first lens element L1 having a shape, a second lens element L2 having a biconvex shape, and a third lens element L3 having a biconvex shape.

  The second lens group G2 includes, in order from the object side to the image surface side, a biconvex fourth lens element L4, a negative meniscus fifth lens element L5 with a convex surface facing the object side, and a convex surface facing the object side. A positive meniscus sixth lens element L6 with a convex surface, a negative meniscus seventh lens element L7 with a convex surface facing the object side, a biconcave eighth lens element L8, and a convex surface facing the object side A positive meniscus ninth lens element L9. Among these, the fifth lens element L5 and the sixth lens element L6, and the eighth lens element L8 and the ninth lens element L9 are joined.

  The third lens group G3 comprises solely a biconvex tenth lens element L10.

  The fourth lens group G4 includes, in order from the object side to the image surface side, a positive meniscus eleventh lens element L11 having a convex surface directed toward the object side, a biconvex twelfth lens element L12, and a biconcave shape. A thirteenth lens element L13, a negative meniscus fourteenth lens element L14 having a convex surface facing the object side, a biconvex fifteenth lens element L15, a biconvex sixteenth lens element L16, and a biconcave shape The seventeenth lens element L17 and the biconvex eighteenth lens element L18. Among these, the twelfth lens element L12 and the thirteenth lens element L13, the fourteenth lens element L14 and the fifteenth lens element L15, and the seventeenth lens element L17 and the eighteenth lens element L18 are cemented. Further, an aperture stop A is provided on the image plane side of the eleventh lens element L11, and a variable beam stop VA is provided on the image plane side of the sixteenth lens element L16.

  The fifth lens group G5 includes, in order from the object side surface to the image surface side, a positive meniscus nineteenth lens element L19 having a convex surface directed toward the image surface side, and a biconcave twentieth lens element L20. Among these, the 19th lens element L19 and the 20th lens element are cemented.

  The sixth lens group G6 comprises solely a bi-convex twenty-first lens element L21.

  The seventh lens group G7 includes, in order from the object side surface to the image surface side, a biconcave 22nd lens element L22 and a positive planoconvex 23rd lens element L23 having a convex surface directed toward the object side. . The fourteenth lens element L14, the fifteenth lens element L15, and the sixteenth lens element L16, which are lens elements constituting the fourth lens group G4, are arranged on the optical axis in order to optically correct image blur, which will be described later. This corresponds to an image blur correction lens group that moves in the vertical direction.

  During zooming from the wide-angle end to the telephoto end during imaging, the third lens group G3 monotonously moves to the object side, and the second lens group G2 and the sixth lens group G6 monotonously move to the image plane side. The fifth lens group G5 moves along a locus convex toward the image plane side. That is, during zooming, the distance between the first lens group G1 and the second lens group G2, the distance between the third lens group G3 and the fourth lens group G4, and the distance between the fifth lens group G5 and the sixth lens group G6. Increases, the distance between the second lens group G2 and the third lens group G3 and the distance between the sixth lens group G6 and the seventh lens group G7 decrease, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Each lens group moves along the optical axis so that the interval changes.

  The fourth lens group G4 includes, in order from the object side to the image side, a first sub lens group G4A (11th lens element L11) having a positive power and a second sub lens group G4B (12th lens) having a negative power. The lens element L12, the thirteenth lens element L13), the third sub-lens group G4C having positive power (the fourteenth lens element L14, the fifteenth lens element L15, the sixteenth lens element L16), and the first lens having positive power. 4 sub lens group G4D (17th lens element L17, 18th lens element L18). The third sub lens group G4C moves in the direction perpendicular to the optical axis in order to optically correct image blur. Further, an aperture stop A is disposed between the first sub lens group G4A and the second sub lens group G4B. Also. Between the third sub lens group G4C and the fourth sub lens group G4D, there is disposed a variable beam stop VA whose diameter changes upon zooming from the wide angle end to the telephoto end. During zooming from the wide-angle end to the telephoto end, the distance between the first sub lens group G4A and the second sub lens group G4B, the distance between the second sub lens group G4B and the third sub lens group G4C, and the third sub lens The distance between the lens group G4C and the fourth sub lens group G4D does not change. During focusing from the infinitely focused state to the close object focused state, the fifth lens group G5 moves to the image plane side along the optical axis in any zooming state, and the sixth lens group G6 It moves to the object side along the optical axis even in the zooming state.

<Embodiment 2>
As shown in FIGS. 5A, 5B, and 5C, in the zoom lens system according to Embodiment 2, the first lens group G1 includes a negative meniscus having a convex surface directed toward the object side in order from the object side to the image surface side. The first lens element L1 having a shape, the second lens element L2 having a positive meniscus shape having a convex surface facing the object side, and the third lens element L3 having a positive meniscus shape having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented.

  The second lens group G2 includes, in order from the object side to the image surface side, a negative meniscus fourth lens element L4 having a convex surface facing the object side, and a positive meniscus fifth lens having a convex surface facing the image surface side. It comprises an element L5, a biconcave sixth lens element L6, and a positive meniscus seventh lens element L7 with a convex surface facing the object side.

  The third lens group G3 comprises solely a biconvex eighth lens element L8.

  The fourth lens group G4 includes, in order from the object side to the image surface side, a positive meniscus ninth lens element L9 having a convex surface directed toward the object side, a biconcave tenth lens element L10, and a convex surface facing the object side. Negative meniscus eleventh lens element L11 facing the lens, biconvex twelfth lens element L12, biconvex thirteenth lens element L13, biconcave fourteenth lens element L14, and biconvex shape The fifteenth lens element L15. Among these, the eleventh lens element L11 and the twelfth lens element L12, and the fourteenth lens element L14 and the fifteenth lens element L15 are joined. Further, an aperture stop A is provided on the image plane side of the ninth lens element L9.

  The fifth lens group G5 includes, in order from the object side surface to the image surface side, a biconvex sixteenth lens element L16 and a biconcave seventeenth lens element L17. Among these, the 16th lens element L16 and the 17th lens element are cemented.

  The sixth lens group G6 comprises solely a biconvex eighteenth lens element L18.

  The seventh lens group G7 includes, in order from the object side surface to the image surface side, a biconcave nineteenth lens element L19 and a biconvex twentieth lens element L20.

  The eleventh lens element L11, the twelfth lens element L12, and the thirteenth lens element L13, which are lens elements constituting the fourth lens group G4, are described later with respect to the optical axis in order to optically correct image blurring. This corresponds to an image blur correction lens group that moves in the vertical direction.

  During zooming from the wide-angle end to the telephoto end during imaging, the third lens group G3 monotonously moves to the object side, and the second lens group G2 and the sixth lens group G6 monotonously move to the image plane side. The fifth lens group G5 moves along a locus convex toward the image plane side. That is, during zooming, the distance between the first lens group G1 and the second lens group G2, the distance between the third lens group G3 and the fourth lens group G4, and the distance between the fifth lens group G5 and the sixth lens group G6. Increases, the distance between the second lens group G2 and the third lens group G3 and the distance between the sixth lens group G6 and the seventh lens group G7 decrease, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Each lens group moves along the optical axis so that the interval changes.

  The fourth lens group G4 includes, in order from the object side to the image side, a first sub lens group G4A (ninth lens element L9) having a positive power and a second sub lens group G4B (tenth lens) having a negative power. A lens element L10), a third sub-lens group G4C having positive power (an eleventh lens element L11, a twelfth lens element L12, a thirteenth lens element L13), and a fourth sub-lens group G4D having positive power (G4D). 14th lens element L14, 15th lens element L15). The third sub lens group G4C moves in the direction perpendicular to the optical axis in order to optically correct image blur. Further, an aperture stop A is disposed between the first sub lens group G4A and the second sub lens group G4B. During zooming from the wide-angle end to the telephoto end, the distance between the first sub lens group G4A and the second sub lens group G4B, the distance between the second sub lens group G4B and the third sub lens group G4C, and the third sub lens The distance between the lens group G4C and the fourth sub lens group G4D does not change.

  During focusing from the infinitely focused state to the close object focused state, the fifth lens group G5 moves to the image plane side along the optical axis in any zooming state, and the sixth lens group G6 It moves to the object side along the optical axis even in the zooming state.

<Embodiment 3>
As shown in FIGS. 9A, 9B, and 9C, in the zoom lens system according to Embodiment 3, the first lens unit G1 includes a negative meniscus having a convex surface directed toward the object side in order from the object side to the image surface side. The first lens element L1 having a shape, the second lens element L2 having a positive meniscus shape having a convex surface facing the object side, and the third lens element L3 having a positive meniscus shape having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented.

  The second lens group G2 includes, in order from the object side to the image surface side, a negative meniscus fourth lens element L4 having a convex surface facing the object side, and a positive meniscus fifth lens having a convex surface facing the image surface side. It comprises an element L5, a biconcave sixth lens element L6, and a positive meniscus seventh lens element L7 with a convex surface facing the object side.

  The third lens group G3 comprises solely a biconvex eighth lens element L8.

  The fourth lens group G4 includes, in order from the object side to the image surface side, a positive meniscus ninth lens element L9 having a convex surface directed toward the object side, a biconcave tenth lens element L10, and a convex surface facing the object side. Negative meniscus eleventh lens element L11 facing the lens, biconvex twelfth lens element L12, biconvex thirteenth lens element L13, biconcave fourteenth lens element L14, and biconvex shape The fifteenth lens element L15. Among these, the eleventh lens element L11 and the twelfth lens element L12, and the fourteenth lens element L14 and the fifteenth lens element L15 are joined. Further, an aperture stop A is provided on the image plane side of the ninth lens element L9.

  The fifth lens group G5 includes, in order from the object side surface to the image surface side, a biconvex sixteenth lens element L16 and a biconcave seventeenth lens element L17. Among these, the 16th lens element L16 and the 17th lens element are cemented.

  The sixth lens group G6 comprises solely a positive meniscus eighteenth lens element L18 with the convex surface facing the image surface side.

  The seventh lens group G7 comprises solely a biconvex nineteenth lens element L19.

  The eighth lens group G8 includes, in order from the object side surface to the image surface side, a biconcave twentieth lens element L20 and a biconvex twenty-first lens element L21.

  The eleventh lens element L11, the twelfth lens element L12, and the thirteenth lens element L13, which are lens elements constituting the fourth lens group G4, are described later with respect to the optical axis in order to optically correct image blurring. This corresponds to an image blur correction lens group that moves in the vertical direction.

  During zooming from the wide-angle end to the telephoto end during imaging, the third lens group G3 moves monotonously to the object side, and the second lens group G2, the sixth lens group G6, and the seventh lens group The fifth lens group G5 moves with a convex locus on the image plane side. That is, during zooming, the distance between the first lens group G1 and the second lens group G2, the distance between the third lens group G3 and the fourth lens group G4, and the distance between the fifth lens group G5 and the sixth lens group G6. Increases, the distance between the second lens group G2 and the third lens group G3 and the distance between the seventh lens group G7 and the eighth lens group G8 decrease, and the distance between the fourth lens group G4 and the fifth lens group G5 increases. Each lens group moves along the optical axis so that the distance and the distance between the sixth lens group G6 and the seventh lens group G7 change.

  The fourth lens group G4 includes, in order from the object side to the image side, a first sub lens group G4A (ninth lens element L9) having a positive power and a second sub lens group G4B (tenth lens) having a negative power. A lens element L10), a third sub-lens group G4C having positive power (an eleventh lens element L11, a twelfth lens element L12, a thirteenth lens element L13), and a fourth sub-lens group G4D having positive power (G4D). 14th lens element L14, 15th lens element L15). The third sub lens group G4C moves in the direction perpendicular to the optical axis in order to optically correct image blur. Further, an aperture stop A is disposed between the first sub lens group G4A and the second sub lens group G4B. During zooming from the wide-angle end to the telephoto end, the distance between the first sub lens group G4A and the second sub lens group G4B, the distance between the second sub lens group G4B and the third sub lens group G4C, and the third sub lens The distance between the lens group G4C and the fourth sub lens group G4D does not change.

  During focusing from the infinitely focused state to the close object focused state, the fifth lens group G5 moves to the image plane side along the optical axis in any zooming state, and the seventh lens group G7 It moves to the object side along the optical axis even in the zooming state.

<Embodiment 4>
As shown in FIGS. 13A, 13B, and 13C, in the zoom lens system according to Embodiment 4, the first lens unit G1 includes a negative meniscus having a convex surface directed toward the object side in order from the object side to the image surface side. The first lens element L1 having a shape, the second lens element L2 having a positive meniscus shape having a convex surface facing the object side, and the third lens element L3 having a positive meniscus shape having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are cemented.

  The second lens group G2 includes, in order from the object side to the image surface side, a negative meniscus fourth lens element L4 having a convex surface directed toward the object side, a biconcave fifth lens element L5, and a biconvex shape. A sixth lens element L6 and a negative meniscus seventh lens element L7 having a convex surface facing the image surface side. Further, the object side surface and the image side surface of the fifth lens element L5 are aspherical surfaces.

  The third lens group G3 includes, in order from the object side to the image surface side, a positive meniscus eighth lens element L8 with a convex surface facing the object side, and a positive meniscus ninth lens element with a convex surface facing the object side L9, a positive meniscus tenth lens element L10 with a convex surface facing the object side, a negative meniscus eleventh lens element L11 with a convex surface facing the object side, and a negative meniscus shape with a convex surface facing the object side It comprises a twelfth lens element L12, a biconvex thirteenth lens element L13, a negative meniscus fourteenth lens element L14 having a convex surface facing the object side, and a biconvex fifteenth lens element. Among them, the tenth lens element L10 and the eleventh lens element L11, and the twelfth lens element L12 and the thirteenth lens element L13 are cemented. Further, the image plane side surface of the ninth lens element L9 and the image plane side surface of the thirteenth lens element L13 are aspherical surfaces. Further, an aperture stop A is provided on the image plane side of the eighth lens element L8.

  The fourth lens group G4 includes, in order from the object side surface to the image surface side, a biconvex sixteenth lens element L16 and a biconcave seventeenth lens element L17. Among these, the 16th lens element L16 and the 17th lens element L17 are cemented.

  In the zoom lens system according to Embodiment 4, the fifth lens unit G5 comprises solely a bi-convex eighteenth lens element L18. The object side surface of the eighteenth lens element L18 is aspheric.

  The sixth lens group G6 comprises solely a bi-concave nineteenth lens element L19. The image surface side surface of the nineteenth lens element L19 is aspheric.

  An image in which a twelfth lens element L12 and a thirteenth lens element L13, which are lens elements constituting the third lens group G3, move in a direction perpendicular to the optical axis to optically correct image blur, which will be described later. This corresponds to the image stabilization lens group.

  During zooming from the wide-angle end to the telephoto end during imaging, the first lens group G1, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 are monotonous toward the object side. The second lens group G2 moves along a locus convex toward the image plane side. That is, during zooming, the distance between the first lens group G1 and the second lens group G2, the distance between the fourth lens group G4 and the fifth lens group G5, and the distance between the sixth lens group and the image plane S are increased. The distance between the second lens group G2 and the third lens group G3 and the distance between the fifth lens group G5 and the sixth lens group G6 are decreased, and the distance between the third lens group G3 and the fourth lens group G4 is changed. As described above, each lens group moves along the optical axis.

  During focusing from the infinitely focused state to the close object focused state, the fourth lens group G4 moves to the image plane side along the optical axis in any zooming state, and the fifth lens group G5 It moves to the object side along the optical axis even in the zooming state.

<Embodiment 5>
As shown in FIGS. 17A, 17B, and 17C, in the zoom lens system according to Embodiment 5, the first lens unit G1 includes a negative meniscus having a convex surface directed toward the object side in order from the object side to the image surface side. The first lens element L1 having a shape, the second lens element L2 having a biconcave shape, and the third lens element L3 having a positive meniscus shape having a convex surface facing the object side.

  The second lens group G2 includes, in order from the object side to the image surface side, a biconvex fourth lens element L4, a biconcave fifth lens element L5, and a negative meniscus shape having a convex surface facing the object side. It comprises a sixth lens element L6, a biconvex seventh lens element L7, and a positive meniscus eighth lens element L8 with the convex surface facing the object side. The object side surface and the image surface side surface of the fourth lens element L4 are aspherical surfaces. Further, an aperture stop A is provided on the image plane side of the fifth lens element L5.

  The third lens group G3 comprises solely a negative meniscus ninth lens element L9 with the convex surface facing the object side.

  The fourth lens group G4 comprises solely a positive meniscus tenth lens element L10 with the convex surface facing the object side. The object-side surface of the tenth lens element L10 is aspheric.

  The fifth lens group G5 comprises solely a bi-concave eleventh lens element L11.

  The sixth lens group G6 comprises solely a positive meniscus twelfth lens element L12 with the convex surface facing the image side.

  During zooming from the wide-angle end to the telephoto end during imaging, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 move monotonously to the object side, and The lens group G1 moves along a locus convex toward the image plane side. That is, during zooming, the distance between the second lens group G2 and the third lens group G3 and the distance between the fifth lens group G5 and the sixth lens group G6 increase, and the first lens group G1 and the second lens group G2 Each lens group along the optical axis so that the distance between the third lens group G3 and the fourth lens group G4 and the distance between the fourth lens group G4 and the fifth lens group G5 change. Move each one.

  At the time of focusing from the infinite focus state to the close object focus state, the third lens group G3 moves to the image plane side along the optical axis in any zooming state, and the fourth lens group G4 has a wide angle. It moves to the object side along the optical axis in a zooming state at an intermediate position from the end.

<Embodiment 6>
As shown in FIGS. 20A, 20B, and 20C, in the zoom lens system according to Embodiment 6, the first lens unit G1 includes a negative meniscus having a convex surface directed toward the object side in order from the object side to the image surface side. The first lens element L1 having a shape, the second lens element L2 having a biconcave shape, and the third lens element L3 having a positive meniscus shape having a convex surface facing the object side.

  The second lens group G2 includes, in order from the object side to the image surface side, a biconvex fourth lens element L4, a biconcave fifth lens element L5, and a negative meniscus shape having a convex surface facing the object side. It comprises a sixth lens element L6, a biconvex seventh lens element L7, and a positive meniscus eighth lens element L8 with the convex surface facing the object side. The object side surface and the image surface side surface of the fourth lens element L4 are aspherical surfaces. Further, an aperture stop A is provided on the image plane side of the fifth lens element L5.

  The third lens group G3 comprises solely a negative meniscus ninth lens element L9 with the convex surface facing the object side.

  The fourth lens group G4 comprises solely a biconvex tenth lens element L10. The object-side surface of the tenth lens element L10 is aspheric.

  The fifth lens group G5 comprises solely a bi-concave eleventh lens element L11.

  The sixth lens group G6 comprises solely a positive meniscus twelfth lens element L12 with the convex surface facing the image side.

  During zooming from the wide-angle end to the telephoto end during imaging, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 move monotonously to the object side, and The lens group G1 and the sixth lens group G6 move along a locus convex toward the image plane side. That is, during zooming, the distance between the second lens group G2 and the third lens group G3 and the distance between the fifth lens group G5 and the sixth lens group G6 increase, and the first lens group G1 and the second lens group G2 , The distance between the third lens group G3 and the fourth lens group G4, the distance between the fourth lens group G4 and the fifth lens group G5, and the distance between the sixth lens group G6 and the image plane S are changed. Thus, each lens group moves along the optical axis.

  At the time of focusing from the infinite focus state to the close object focus state, the third lens group G3 moves to the image plane side along the optical axis in any zooming state, and the fourth lens group G4 has a wide angle. It moves to the object side along the optical axis in a zooming state at an intermediate position from the end.

<Embodiment 7>
As shown in FIGS. 23A, 23B, and 23C, in the zoom lens system according to Embodiment 7, the first lens unit G1 includes a negative meniscus having a convex surface directed toward the object side in this order from the object side to the image surface side. The first lens element L1 having a shape, the second lens element L2 having a biconvex shape, and the third lens element L3 having a positive meniscus shape having a convex surface facing the object side. Among these, the first lens element L1 and the second lens element L2 are respectively joined.

  The second lens group G2 includes, in order from the object side to the image surface side, a biconvex fourth lens element L4, a biconcave fifth lens element L5, and a positive meniscus shape with the convex surface facing the object side. It comprises a sixth lens element L6, a negative meniscus seventh lens element L7 having a convex surface facing the object side, and a negative meniscus eighth lens element L8 convex on the image side. Among these, the fourth lens element L4 and the fifth lens element L5, and the sixth lens element L6 and the seventh lens element L7 are joined.

  The third lens group G3 includes, in order from the object side to the image surface side, a positive meniscus ninth lens element L9 having a convex surface directed toward the object side, a biconvex tenth lens element L10, and a biconcave shape. An eleventh lens element L11, a negative meniscus twelfth lens element L12 with a convex surface facing the object side, a biconvex thirteenth lens element L13, a biconvex fourteenth lens element L14, and a biconcave shape The fifteenth lens element L15 and a biconvex sixteenth lens element L16. Among these, the tenth lens element L10 and the eleventh lens element L11, the twelfth lens element L12 and the thirteenth lens element L13, and the fifteenth lens element L15 and the sixteenth lens element L16 are cemented. Further, an aperture stop A is provided on the image plane side of the eleventh lens element L11.

  The fourth lens group G4 includes, in order from the object side surface to the image surface side, a biconvex seventeenth lens element L17 and a biconcave eighteenth lens element L18. Among these, the seventeenth lens element L17 and the eighteenth lens element L18 are cemented.

  The fifth lens group G6 comprises solely a bi-convex nineteenth lens element L19.

  The sixth lens group G6 comprises solely a bi-concave twentieth lens element L20. Note that the twelfth lens element L12, the thirteenth lens element L13, and the fourteenth lens element L14, which are lens elements constituting the third lens group G3, are arranged on the optical axis in order to optically correct image blur, which will be described later. This corresponds to an image blur correction lens group that moves in the vertical direction.

  During zooming from the wide-angle end to the telephoto end during imaging, the second lens group G2 moves monotonously to the image plane side, and the fourth lens group G4 moves along a locus locus convex to the image plane side. The fifth lens group G5 moves along a locus convex toward the object side, and the first lens group, the third lens group, and the sixth lens group are fixed with respect to the image plane. That is, during zooming, the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the third lens group G3 and the fourth lens. Each lens group follows the optical axis so that the distance between the group G4, the distance between the fourth lens group G4 and the fifth lens group G5, and the distance between the fifth lens group G5 and the sixth lens group G6 change. Move each.

  During focusing from the infinitely focused state to the close object focused state, the fourth lens group G4 moves to the image plane side along the optical axis in any zooming state, and the fifth lens group G5 It moves to the object side along the optical axis even in the zooming state.

[2. effect]
In the zoom lens systems according to Embodiments 1 to 7, the zoom lens system includes a plurality of lens groups each including at least one lens element, and has a negative power in order from the object side to the image side. A front group including one focus lens group, and a rear group including a second focus lens group having a positive power. At the time of zooming from the wide angle end to the telephoto end, the first focus lens group and the second focus lens group move along the optical axis, and the first focus lens is focused on from the infinite focus state to the close object focus state. Since the focus lens group and the second focus lens group move, the amount of movement of the focus lens group can be reduced and the lens system can be downsized. In addition, the focus lens group is composed of a focus lens group having negative power and a focus lens group having positive power in order from the object side to the image side, so that the focus shift due to the movement of the two focus lens groups is not canceled. There is an advantage that the field curvature generated by the focus movement of the two focus lens groups can be canceled each other, and the field curvature can be corrected well in each zoom range from the infinite focus state to the close object focus state. .

  In the zoom lens systems according to Embodiments 1 to 7, the aperture stop A is disposed, and the first focus lens group and the second focus lens group are disposed on the image side from the aperture stop A. It can be made smaller and lighter.

  In the zoom lens systems according to Embodiments 1 to 7, the first focus lens group is configured so that the imaging position approaches the imaging surface side when focusing from the infinite focus state to the close object focus state. Since the second focus lens group moves toward the object side and performs focusing, the amount of movement of each focus lens can be reduced, and the lens can be miniaturized.

  In the zoom lens system according to Embodiments 1 to 7, the first focus lens group changes in a convex manner toward the image plane side when zooming from the wide-angle end to the telephoto end, and therefore moves from the wide-angle end to the telephoto end. The spherical aberration can be reduced.

  In the zoom lens system according to Embodiments 1 to 7, the second focus lens group moves in a direction approaching the group adjacent to the image side when zooming from the wide-angle end to the telephoto end. The coma aberration can be reduced.

  In the zoom lens systems according to Embodiments 1 to 7, since the second focus lens group is composed of a single lens element having positive power, the second focus lens group can be reduced in weight and the focus lens group is driven. It is possible to reduce the size of the actuator and the like so that the lens barrel can be made smaller.

  In the zoom lens systems according to Embodiments 1 to 4 and 7, the first focus lens group is composed of a cemented lens of a single lens element having a positive power and a single lens element having a negative power in order from the object. The first focus lens group can be reduced in weight, the actuator and the like can be reduced in size, and the lens barrel can be reduced in size.

  In the zoom lens systems according to Embodiments 1 to 4 and 7, since the first lens group located closest to the object side has positive power, the diameter of the diaphragm A can be reduced, and the lens barrel diameter can be reduced. Can be small.

  In the zoom lens systems according to Embodiments 1 to 3 and 7, when zooming from the wide-angle end to the telephoto end, the first lens unit is fixed with respect to the image plane, so that the first lens unit is movable. This eliminates the need for a gap in the lens barrel that needs to be provided, and prevents dust from entering.

  In the zoom lens system according to Embodiments 1 to 3, at least two lens groups that move when zooming from the wide-angle end to the telephoto end are located between the first lens unit positioned closest to the object side and the aperture stop A. Therefore, various aberrations, particularly spherical aberration, can be favorably corrected at the zoom position from the wide-angle end to the telephoto end.

  In the zoom lens systems according to Embodiments 1 to 4, in the front group, the first lens group G1 having positive power in order from the object side to the image side on the object side of the first focus lens group, negative power Since the second lens group G2 and the third lens group G3 having positive power are included, various aberrations at each zoom position from the wide-angle end to the telephoto end can be favorably corrected. Further, the focus lens group can be reduced in weight, the actuator for driving the focus lens group can be reduced in size, and the lens barrel diameter can be reduced.

  In the zoom lens systems according to Embodiments 1 to 3, since the third lens group G3 is composed of one positive single lens element, the weight of the third lens group can be reduced, and the third lens group at the time of manufacture can be reduced. Fixing can be done easily.

  In the zoom lens systems according to Embodiments 1 to 3, in the front group, the lens group immediately on the object side of the first focus lens group is a first sub lens group having a positive power in order from the object side to the image side. An aperture stop A, a second sub-lens group having negative power, a third sub-lens group having positive power that is moved in a direction perpendicular to the optical axis to correct image blur, and a fourth sub-lens Have a group. The first sub-lens group can reduce the occurrence of various aberrations during image blur correction, and can also reduce the amount of movement necessary for image blur correction, thereby reducing the lens barrel diameter.

  In the zoom lens system according to Embodiment 1, the diameter of the first focus lens unit changes its diameter at the time of zooming from the wide angle end to the telephoto end on the immediate image plane side of the image blur correction sub lens unit in the lens unit on the object side. And a variable beam stop VA. As a result, the upper ray of the off-axis light beam can be cut at each zoom position from the wide-angle end to the telephoto end, so that the upper ray of each zoom position can be cut, and various aberrations of the intermediate image height at each zoom position can be reduced. it can.

  In the zoom lens systems according to Embodiments 1 to 3 and 7, the image blur correction sub-lens group includes a cemented lens of a lens having negative power, a lens having positive power, and a single lens having positive power in order from the object. Therefore, the occurrence of various aberrations during image blur correction can be reduced.

  In the zoom lens systems according to Embodiments 1 to 7, each lens group moves in a direction along the optical axis so that the distance between the lens groups changes during zooming. The zoom lens system according to each embodiment has a high optical performance from an infinite focus state to a close object focus state by setting each lens group to a desired power arrangement, and has a short overall length and an outer diameter. Makes it possible to be small.

  As described above, Embodiments 1 to 6 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed.

  Hereinafter, conditions that can be satisfied by a lens system such as the lens systems according to Embodiments 1 to 6 will be described. A plurality of possible conditions are defined for the lens system according to each embodiment, but a lens system configuration that satisfies all of the plurality of conditions is most effective. However, by satisfying individual conditions, it is also possible to obtain lens systems that exhibit corresponding effects.

  For example, in the zoom lens systems according to Embodiments 1 to 7, the zoom lens system includes a plurality of lens groups each including at least one lens element, and the negative power is sequentially applied from the object side to the image plane side. A first focus lens group and a rear group including a second focus lens group having a positive power, and the first focus lens group and the second focus lens at the time of zooming from the wide-angle end to the telephoto end The group moves along the optical axis, and when focusing from the infinitely focused state to the close object focused state, the first focus lens group and the second focus lens group move to perform focusing (hereinafter referred to as this It is preferable that the lens configuration is referred to as a basic configuration of the embodiment) and the following conditional expression (1) is satisfied.

−20 <β1t / β1w × β2t / β2w <20 (1)
here,
β1t: lateral magnification at the telephoto end of the first focus lens group β1w: lateral magnification at the wide-angle end of the first focus lens group β2t: lateral magnification at the telephoto end of the second focus lens group β2w: of the second focus lens group The horizontal magnification at the wide-angle end.

  Conditional expression (1) is a condition that defines the contribution of the first focus lens group and the second focus lens group to zooming. By satisfying conditional expression (1), it is possible to reduce the amount of aberrations while shortening the overall length. If the lower limit of conditional expression (1) is not reached, the burden of zooming on the focus lens group will be reduced, and zooming will have to be performed in other groups, and the total length will be increased. Conversely, the upper limit of conditional expression (1) If the value exceeds the above, the burden on the zoom lens of the focus lens group will be too great, the amount of spherical aberration generated in the focus lens group will increase, and the performance will deteriorate. The above-described effect can be further achieved by satisfying at least one of the following conditional expressions (1) ′ and (1) ″.

1.05 <β1t / β1w × β2t / β2w (1) ′
β1t / β1w × β2t / β2w <2.00 (1) ''
For example, it is preferable that the zoom lens system according to Embodiments 1 to 7 has a basic configuration and satisfies the following conditional expression (2).

0.25 <| f1 / f2 | <1.30 (2)
here,
f1: Focal length of the first focus lens group f2: Focal length of the second focus lens group.

  Conditional expression (2) defines the power ratio between the first focus lens group and the second focus lens group. By satisfying conditional expression (2), it is possible to reduce the amount of field curvature while realizing downsizing of the lens barrel. If the lower limit of conditional expression (2) is not reached, the power of the first focus lens group becomes too strong, the diameter of the second focus lens group becomes larger, and the second focus lens group becomes heavier, so that the actuator becomes larger and the mirror becomes larger. The cylinder diameter increases. On the other hand, if the upper limit of conditional expression (2) is exceeded, the field curvature that has been canceled by the movement of the first focus lens group and the second focus lens group cannot be corrected, and the field curvature deteriorates during close-up photography. To do. The above effect can be further achieved by further satisfying at least one of the following conditional expressions (2) ′ and (2) ″.

0.50 <| f1 / f2 | (2) ′
| f1 / f2 | <1.20 (2) ''
For example, as in the zoom lens systems according to Embodiments 1, 2, 3, 5, and 6, the lens having the basic configuration and having the strongest positive power among the lens elements constituting the second focus lens group is shown. It is preferable that the following conditional expression is satisfied.

νp2 <30 (3)
Where νp2 is the Abbe number of the lens having the strongest positive power among the lens elements constituting the second focus lens group.

  Conditional expression (3) defines the Abbe number of the lens having the strongest positive power among the lens elements constituting the second focus lens group. By satisfying conditional expression (3), it is possible to correct chromatic aberration satisfactorily at each zoom position. If the upper limit of conditional expression (3) is exceeded, chromatic aberration from the wide-angle end to the telephoto end cannot be corrected well.

  For example, like the zoom lens systems according to Embodiments 1 to 4 and 7, the first focus lens group includes at least a single lens element having a positive power and a single lens element having a negative power. It is preferable that the following conditional expression (4) is satisfied.

νp1 <30 (4)
here,
νp1: Abbe number of the lens having the strongest positive power among the lenses constituting the first focus lens group.

  Conditional expression (4) defines the Abbe number of the lens having the strongest positive power among the lenses constituting the first focus lens group. By satisfying conditional expression (4), it is possible to satisfactorily correct chromatic aberration from an infinitely focused state to a close object focused state. If the upper limit is exceeded, chromatic aberration from infinity to proximity cannot be corrected satisfactorily.

  For example, it is preferable that the zoom lens system according to Embodiments 1 to 6 has a basic configuration and satisfies the following conditional expression (5).

mf2w / mf1w> mf2t / mf1t (5)
Here, mf2w: the amount of movement of the second focus lens group when focusing on an object at an arbitrary distance from infinity at the wide angle end mf1w: movement of the first focus lens group when focusing on an object at an arbitrary distance from infinity at the wide angle end Movement amount mf2t: Movement amount of the second focus lens group when focusing on an object at an arbitrary distance from infinity at the telephoto end mf1t: Movement of the first focus lens group when focusing on an object at an arbitrary distance from infinity at the telephoto end The amount of movement.

  Conditional expression (5) defines the movement amount ratio between the wide-angle end and the telephoto end of the first focus lens group and the second focus lens group. By satisfying conditional expression (5), it is possible to satisfactorily correct aberrations at each zoom position. In particular, the spherical aberration can be favorably corrected. If the conditional expression (5) is not satisfied, aberration correction from infinity to the close cannot be performed at each zoom position.

  Each lens group constituting the zoom lens system according to Embodiments 1 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. In particular, in a refractive / diffractive hybrid lens element, it is preferable to form a diffractive structure at the interface of media having different refractive indexes, since the wavelength dependency of diffraction efficiency is improved.

(Embodiment 8)
FIG. 27 is a schematic configuration diagram of a lens interchangeable digital camera system according to the eighth embodiment.

  The interchangeable lens digital camera system 100 according to the present embodiment includes a camera body 101 and an interchangeable lens apparatus 201 that is detachably connected to the camera body 101.

  The camera body 101 receives an optical image formed by the zoom lens system 202 of the interchangeable lens apparatus 201, and displays an image sensor 102 that converts the optical image into an electrical image signal, and an image signal converted by the image sensor 102. A liquid crystal monitor 103 and a camera mount unit 104 are included. On the other hand, the interchangeable lens apparatus 201 includes a zoom lens system 202 according to any one of Embodiments 1 to 6, a lens barrel 203 that holds the zoom lens system 202, and a lens mount unit connected to the camera mount unit 104 of the camera body. 204. The camera mount unit 104 and the lens mount unit 204 electrically connect not only a physical connection but also a controller (not shown) in the camera body 101 and a controller (not shown) in the interchangeable lens device 201. It also functions as an interface that enables mutual signal exchange. Note that FIG. 23 illustrates a case where the zoom lens system according to Embodiment 1 is used as the zoom lens system 202.

  In this embodiment, since the zoom lens system 202 according to any one of Embodiments 1 to 7 is used, an interchangeable lens apparatus that is compact and excellent in imaging performance can be realized at low cost. In addition, the entire interchangeable lens digital camera system 100 according to the present embodiment can be reduced in size and performance. In the zoom lens systems according to Embodiments 1 to 6, it is not necessary to use the entire zooming area. That is, a range in which optical performance is ensured according to a desired zooming area may be cut out and used as a zoom lens system having a lower magnification than the zoom lens system described in the corresponding numerical examples 1 to 6 below. Good.

  Hereinafter, numerical examples in which the zoom lens systems according to Embodiments 1 to 6 are specifically implemented will be described. In each numerical example, the unit of length in the table is “mm”, and the unit of angle of view is “°”. In each numerical example, r is a radius of curvature, d is a surface interval, nd is a refractive index with respect to the d line, and νd is an Abbe number with respect to 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 [Equation 2].

here,
Z: distance from a point on the aspheric surface having a height h from the optical axis to the tangent plane of the aspheric vertex,
h: height from the optical axis,
r: vertex radius of curvature,
κ: conic constant,
An: n-order aspherical coefficient.

  2, 6, 10, 14, 18, 21, and 24 are longitudinal aberration diagrams of the zoom lens system according to Numerical Examples 1 to 7 in an infinitely focused state, respectively.

  FIGS. 3, 7, 11, 15, 19, 22, and 25 are longitudinal aberration diagrams of the zoom lens system according to Numerical Examples 1 to 7 in the close object in-focus state. The object distance in each numerical example is as shown below.

Numerical example 1 1200 mm
Numerical example 2 800 mm
Numerical example 3 800 mm
Numerical example 4 550 mm
Numerical example 5 300 mm
Numerical example 6 300 mm
Numerical example 7 1000 mm
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 (SA (mm)), astigmatism (AST (mm)), and distortion (DIS (%)) in order from the left side. In the spherical aberration diagram, the vertical axis represents the F number (indicated by F in the figure), the solid line is the d line (d-line), the short broken line is the F line (F-line), and the long broken line is the C line (C- line). In the astigmatism diagram, the vertical axis represents the image height (indicated by H in the figure), the solid line represents the sagittal plane (indicated by s), and the broken line represents the meridional plane (indicated by m in the figure). is there. In the distortion diagram, the vertical axis represents the image height (indicated by H in the figure).

  4, 8, 12, 16, and 26 are lateral aberration diagrams at the telephoto end of the zoom lens systems according to Numerical Examples 1 to 4 and 7, respectively.

  In each lateral aberration diagram, the upper three aberration diagrams show a basic state in which image blur correction at the telephoto end is not performed, and the lower three aberration diagrams show an image blur correction lens group (Numerical Example 1: Fourth lens group G4). Fourteenth lens element L14, Fifteenth lens element L15 and Sixteenth lens element L16, Numerical examples 2 and 3: The eleventh lens element L11, the twelfth lens element L12 and the thirteenth lens element L13 of the fourth lens group G4, the numerical values Example 4 This corresponds to the image blur correction state at the telephoto end where the twelfth lens element L12 and the thirteenth lens element L13) of the third lens group G3 are moved by a predetermined amount in the direction perpendicular to the optical axis. Of the lateral aberration diagrams in the basic state, the upper row shows the lateral aberration at the image point of 70% of the maximum image height, the middle row shows the lateral aberration at the axial image point, and the lower row shows the lateral aberration at the image point of -70% of the maximum image height. Respectively. In each lateral aberration diagram in the image blur correction state, the upper row shows the lateral aberration at the image point of 70% of the maximum image height, the middle row shows the lateral aberration at the axial image point, and the lower row shows the image point at −70% of the maximum image height. Each corresponds to lateral aberration. 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 (d-line), the short broken line is the F line (F-line), and the long broken line is the C line ( C-line) characteristics. In each lateral aberration diagram, the meridional plane is a plane including the optical axis of the first lens group G1 and the optical axis of the image blur correction lens group.

  In the zoom lens system of each numerical example, the amount of movement in the direction perpendicular to the optical axis of the image blur correction lens group in the image blur correction state at the telephoto end is as follows.

Numerical example 1 0.9000 mm
Numerical example 2 0.7486 mm
Numerical example 3 0.8102 mm
Numerical example 4 0.6081 mm
Numerical example 7 0.8829 mm
When the shooting distance is ∞ and the zoom lens system is tilted by a predetermined angle at the telephoto end, the image decentering amount is the image when the image blur correction lens group translates by the above values in the direction perpendicular to the optical axis. Equal to eccentricity.

  As can be seen from the respective lateral aberration diagrams, the symmetry of the lateral aberration at the axial image point is good. In addition, when the lateral aberration at the + 70% image point and the lateral aberration at the -70% image point are compared between the basic state and the image blur correction state, the curvature is small and the inclination of the aberration curve is almost equal. It can be seen that the aberration and decentration astigmatism are 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. Therefore, at any zoom position, it is possible to perform sufficient image blur correction without deteriorating the imaging characteristics with respect to the image blur correction angle up to a predetermined angle.

(Numerical example 1)
The zoom lens system of Numerical Example 1 corresponds to Embodiment 1 shown in FIGS. 1A to 1C. The surface data of the zoom lens system of Numerical Example 1 is shown as data 1, the various data in the infinite focus state is shown in data 2, and the various data in the close object focus state is shown in data 3.

Data 1 (surface data)
Surface number rd nd vd
Object ∞
1 178.66790 2.40000 1.90366 31.3
2 88.73070 1.02470
3 88.73070 9.67830 1.43700 95.1
4 -590.40040 0.20000
5 88.40080 8.28890 1.43700 95.1
6 -1630.19590 Variable
7 293.10870 4.05020 1.84666 23.8
8 -307.24960 2.21160
9 246.30560 1.80000 1.59349 67.0
10 55.02840 3.03610 1.69895 30.0
11 90.90590 2.88380
12 2761.15140 1.60000 1.59349 67.0
13 106.44040 5.78450
14 -70.13620 1.50000 1.72916 54.7
15 76.00610 2.23850 1.78472 25.7
16 158.63790 Variable
17 70.89880 6.45930 1.83481 42.7
18 -183.85220 Variable
19 44.71190 4.32610 1.43700 95.1
20 108.24170 5.49810
21 (Aperture) ∞ 2.50000
22 346.10340 3.74600 1.49700 81.6
23 -68.32480 1.30000 2.00100 29.1
24 40.83250 2.58620
25 69.59730 1.30000 1.80610 33.3
26 42.15810 6.59070 1.48749 70.4
27 -83.40530 0.20000
28 77.87690 3.57650 1.71300 53.9
29 -257.08570 1.35690
30 ∞ 5.04720
31 -49.64730 1.30000 1.51823 59.0
32 36.36000 7.92230 1.62041 60.3
33 -48.73690 Variable
34 -149.83270 2.73050 1.80518 25.5
35 -41.70390 0.80000 1.58144 40.9
36 38.56360 Variable
37 143.61370 4.64160 1.84666 23.8
38 -81.00210 Variable
39 -65.44990 1.50000 1.72342 38.0
40 48.76690 3.09120
41 45.26650 8.21380 1.62041 60.3
42 ∞ 31.01840
Image plane ∞

Data 2 (Various data in focus at infinity)
Zoom ratio 2.95713
Wide angle Medium telephoto Focal length 92.2864 158.6671 272.9028
F number 2.90761 3.28448 4.10547
Angle of view 13.1946 7.6150 4.4177
Image height 21.6300 21.6300 21.6300
d6 1.1675 29.0997 53.3278
d16 61.1833 29.6605 1.0000
d18 1.0000 4.5905 9.0230
d33 2.5391 6.8311 2.5000
d36 23.6362 24.1859 34.8950
d38 14.0722 9.2305 2.8526

Zoom lens group data Group Start surface Focal length
1 1 172.45338
2 7 -59.93162
3 17 62.00739
4 19 148.56478
5 34 -65.94136
6 37 61.75545
7 39 -90.17525

Data 3 (Various data in the proximity object in-focus state)
Wide angle Medium telephoto Object distance 1200.0000 1200.0000 1200.0000
d6 1.1675 29.0997 53.3278
d16 61.1833 29.6605 1.0000
d18 1.0000 4.5905 9.0230
d33 4.3347 12.5970 19.5673
d36 20.6573 15.6675 12.2099
d38 15.2555 11.9830 8.4703

(Numerical example 2)
The zoom lens system of Numerical Example 2 corresponds to Embodiment 2 shown in FIGS. 5A to 5C. The surface data of the zoom lens system of the numerical value example 2 is shown as data 4, the various data in the infinite focus state is shown in data 5, and the various data in the close object focus state is shown in data 6.

Data 4 (surface data)
Surface number rd nd vd
Object ∞
1 127.28940 2.00000 1.84666 23.8
2 75.68600 9.84220 1.49700 81.6
3 591.32420 0.20000
4 95.83010 7.80840 1.49700 81.6
5 4810.63100 Variable
6 406.78590 2.00000 1.61800 63.4
7 40.71820 10.19880
8 -89.70220 3.09740 1.84666 23.8
9 -53.56930 1.47370
10 -49.30490 1.50000 1.69680 55.5
11 1219.95860 0.10000
12 86.20020 3.89380 1.84666 23.8
13 426.99000 Variable
14 82.42500 6.74770 1.72916 54.7
15 -216.68920 Variable
16 51.93320 3.03920 1.72916 54.7
17 100.28070 5.23110
18 (Aperture) ∞ 3.18540
19 -195.70310 1.30000 1.80610 33.3
20 37.44250 3.41120
21 97.22280 1.30000 1.80518 25.5
22 45.62660 5.58430 1.59349 67.0
23 -139.81330 0.20000
24 77.07170 3.64640 1.72916 54.7
25 -269.26660 3.06900
26 -70.29040 1.30000 1.60342 38.0
27 28.51900 9.61420 1.69680 55.5
28 -64.57000 Variable
29 608.64200 3.08720 1.84666 23.8
30 -47.31810 0.80000 1.74400 44.7
31 39.18120 Variable
32 86.52460 5.55610 1.84666 23.8
33 -83.27500 Variable
34 -85.44620 1.50000 1.84666 23.8
35 44.34060 4.05900
36 43.61300 8.89190 1.54814 45.8
37 -925.26930 31.01840
Image plane ∞

Data 5 (Various data in focus at infinity)
Zoom ratio 2.71571
Wide angle Medium telephoto Focal length 71.7986 118.2340 194.9840
F number 2.90439 2.90288 2.89938
Angle of View 16.9789 10.1987 6.1666
Image height 21.6300 21.6300 21.6300
d5 1.0000 24.6664 46.3969
d13 65.3746 31.3898 1.0000
d15 1.0000 11.3183 19.9777
d28 3.7844 5.4532 2.5000
d31 18.8647 21.3479 29.4698
d33 11.3206 7.1685 2.0000

Zoom lens group data Group Start surface Focal length
1 1 160.73980
2 6 -72.60365
3 14 82.67750
4 16 105.47904
5 29 -65.11249
6 32 50.88285
7 34 -70.01931

Data 6 (Various data in the near-in-focus state)
Wide angle Medium telephoto Object distance 800.0000 800.0000 800.0000
d5 1.0000 24.6664 46.3969
d13 65.3746 31.3898 1.0000
d15 1.0000 11.3183 19.9777
d28 5.6109 10.2722 14.5214
d31 16.2374 14.6449 13.2963
d33 12.1214 9.0526 6.1520

(Numerical Example 3)
The zoom lens system of Numerical Example 3 corresponds to Embodiment 3 shown in FIGS. 9A to 9C. The surface data of the zoom lens system of the numerical value example 3 is shown in data 7, the various data in the infinite focus state is shown in data 8, and the various data in the close object focus state are shown in data 9.

Data 7 (surface data)
Surface number rd nd vd
Object ∞
1 111.97000 2.00000 1.84666 23.8
2 71.81730 9.84930 1.49700 81.6
3 501.86860 0.20000
4 96.80530 6.95640 1.49700 81.6
5 1171.36130 Variable
6 659.28830 2.00000 1.61800 63.4
7 41.70630 9.40220
8 -98.44380 3.07960 1.84666 23.8
9 -55.59200 1.43920
10 -51.10510 1.50000 1.69680 55.5
11 554.35890 0.10000
12 84.15800 3.66770 1.84666 23.8
13 383.96290 Variable
14 80.66220 6.71970 1.72916 54.7
15 -178.85550 Variable
16 60.05650 2.35990 1.72916 54.7
17 100.84750 5.16620
18 (Aperture) ∞ 3.43330
19 -141.16450 1.30000 1.80610 33.3
20 41.82640 3.12720
21 105.49950 1.30000 1.80518 25.5
22 50.15440 5.16410 1.59349 67.0
23 -158.64980 0.20000
24 88.67910 3.46330 1.72916 54.7
25 -236.97680 2.87510
26 -77.26210 1.30000 1.60342 38.0
27 30.61410 8.89320 1.71300 53.9
28 -78.39990 Variable
29 470.93840 3.14990 1.84666 23.8
30 -50.28260 0.80000 1.80610 40.7
31 49.74860 Variable
32 -1778.25360 2.56250 1.80420 46.5
33 -114.71500 Variable
34 100.64850 5.03180 1.84666 23.8
35 -106.66260 Variable
36 -111.75280 1.50000 1.80518 25.5
37 38.86220 4.83610
38 38.81250 7.79020 1.51742 52.1
39 156.01700 32.43440
Image plane ∞

Data 8 (various data in infinite focus state)
Zoom ratio 2.71599
Wide angle Medium telephoto Focal length 71.7938 118.2294 194.9913
F number 2.90481 2.90305 2.89965
Angle of View 17.0090 10.2122 6.1786
Image height 21.6300 21.6300 21.6300
d5 1.0784 25.2663 47.9595
d13 62.0544 30.1422 1.0000
d15 1.0000 8.7242 15.1733
d28 5.5198 7.5463 2.5000
d31 19.3999 21.1006 27.7661
d33 3.0000 2.7565 6.0000
d35 10.3463 6.8625 2.0000

Zoom lens group data Group Start focal length
1 1 157.07678
2 6 -71.61874
3 14 77.08155
4 16 160.81442
5 29 -73.89214
6 32 152.37686
7 34 61.85090
8 36 -59.40669

Data 9 (Various data when in close proximity to the object)
Wide angle Medium telephoto Object distance 800.0000 800.0000 800.0000
Focal length 68.7470 105.2069 145.9848
d5 1.0784 25.2663 47.9595
d13 62.0544 30.1422 1.0000
d15 1.0000 8.7242 15.1733
d28 8.0529 14.1701 19.0413
d31 16.8669 14.4768 11.2248
d33 2.1829 0.9077 2.3130
d35 11.1633 8.7114 5.6869

(Numerical example 4)
The zoom lens system of Numerical Example 4 corresponds to Embodiment 4 shown in FIGS. 13A to 13C. The surface data of the zoom lens system of Numerical Example 4 is the data 10, the aspherical data is the data 11, the various data in the infinite focus state is the data 12, and the various data in the close object in-focus state is the data 13. Shown in

Data 10 (surface data)
Surface number rd nd vd
Object ∞
1 114.84260 2.40000 1.90366 31.3
2 71.00500 8.94010 1.49700 81.6
3 496.79980 0.20000
4 73.51540 6.10740 1.59282 68.6
5 415.79190 Variable
6 152.98880 2.00000 1.80420 46.5
7 21.04540 9.52770
8 * -57.67750 1.80000 1.77200 50.0
9 * 65.78610 0.20000
10 50.42170 5.72530 1.84666 23.8
11 -67.41920 1.23260
12 -40.99750 1.50000 1.80420 46.5
13 -102.46900 Variable
14 26.13320 2.93750 1.70154 41.1
15 74.73680 2.21140
16 (Aperture) ∞ 1.50350
17 41.72730 1.67660 1.69350 53.2
18 * 116.24750 0.94210
19 40.10190 1.96610 1.43700 95.1
20 137.37950 0.90000 1.95375 32.3
21 25.47980 1.34360
22 26.86700 0.90000 1.80610 33.3
23 18.99230 5.55500 1.49710 81.6
24 * -57.70970 1.00000
25 226.16630 0.90000 1.67270 32.2
26 30.91200 5.28050
27 41.53290 4.72610 1.56883 56.0
28 -30.30710 Variable
29 79.30570 1.42770 1.84666 23.8
30 -543.85120 0.80000 1.62041 60.3
31 20.70410 Variable
32 * 58.90380 2.98090 1.52500 70.3
33 -76.87520 Variable
34 -76.39650 1.20000 1.77200 50.0
35 * 74.00130 Variable
Image plane ∞

Data 11 (Aspherical data)
8th page
K = 0.00000E + 00, A4 = -6.37742E-07, A6 = 0.00000E + 00
9th page
K = 0.00000E + 00, A4 = -2.84099E-06, A6 = 7.71332E-10
18th page
K = 0.00000E + 00, A4 = 1.58588E-05, A6 = 0.00000E + 00
24th page
K = 0.00000E + 00, A4 = 6.72611E-06, A6 = 0.00000E + 00
32nd page
K = 0.00000E + 00, A4 = -1.16999E-05, A6 = 0.00000E + 00
35th page
K = 0.00000E + 00, A4 = -1.50000E-05, A6 = 0.00000E + 00

Data 12 (various data in infinite focus state)
Zoom ratio 9.39938
Wide angle Medium telephoto Focal length 24.7429 75.7728 232.5679
F number 3.60647 5.14760 6.47988
Angle of View 41.9623 15.7395 5.2593
Image height 20.0000 21.6300 21.6300
d5 1.0000 25.5409 65.3966
d13 39.9392 11.1637 1.0000
d28 2.5000 6.6465 2.7390
d31 7.4731 10.8194 14.6240
d33 7.1636 3.7533 2.0000
d35 20.7449 45.4178 73.4381

Zoom lens group data Group Start focal length
1 1 128.96217
2 6 -23.84464
3 14 31.77283
4 29 -54.15475
5 32 64.00714
6 34 -48.52312

Data 13 (various data in the state of focusing on a close object)
Wide-angle Medium Tele-object distance 550.0000 550.0000 550.0000
d5 1.0000 25.5409 65.3966
d13 39.9392 11.1637 1.0000
d28 2.8336 8.6605 11.8718
d31 6.8167 8.5191 5.3920
d33 7.4863 4.0396 2.0991
d35 20.7449 45.4178 73.4381

(Numerical example 5)
The zoom lens system of Numerical Example 5 corresponds to Embodiment 5 shown in FIGS. 17A to 17C. The surface data of the zoom lens system of Numerical Example 5 is data 14, the aspherical data is data 15, the various data in the infinite focus state is data 16, and the various data in the close object focus state is data 17. Show.

Data 14 (surface data)
Surface number rd nd vd
Object ∞
1 63.71310 1.50000 1.83400 37.3
2 22.42690 9.55270
3 -102.09940 1.20000 1.71300 53.9
4 65.32570 3.29240
5 43.37070 4.30000 1.84666 23.8
6 172.99030 Variable
7 * 22.88250 5.92740 1.77200 50.0
8 * -93.87200 0.50000
9 -104.95110 0.90000 1.80518 25.5
10 153.87360 5.70320
11 (Aperture) ∞ 1.00000
12 31.67630 0.80000 1.80610 33.3
13 11.84300 6.35700 1.49700 81.6
14 -78.92360 0.20000
15 39.67010 0.93460 1.84666 23.8
16 76.08570 Variable
17 55.21500 0.60000 1.54072 47.2
18 15.90340 Variable
19 * 56.55450 1.50000 1.82115 24.1
20 106.35400 Variable
21 -60.31570 0.80000 1.70154 41.1
22 346.99950 Variable
23 -84.49040 4.51080 1.48749 70.4
24 -34.10000 20.26820
Image plane ∞

Data 15 (Aspherical data)
7th page
K = 0.00000E + 00, A4 = -4.78437E-06, A6 = 0.00000E + 00
8th page
K = 0.00000E + 00, A4 = 5.37820E-06, A6 = 0.00000E + 00
19th page
K = 0.00000E + 00, A4 = -8.02483E-07, A6 = 7.68586E-08

Data 16 (various data in infinite focus state)
Zoom ratio 2.94297
Wide angle Medium telephoto Focal length 24.7198 44.9999 72.7498
F number 3.60527 4.99559 5.76846
Angle of view 44.4804 25.5043 16.5655
Image height 21.6300 21.6300 21.6300
d6 36.9765 11.9226 1.0000
d16 2.2167 4.6245 6.5836
d18 5.5129 6.2149 5.1436
d20 2.2618 2.4880 2.2446
d22 1.6856 13.4482 33.6818

Zoom lens group data Group Start surface Focal length
1 1 -39.05840
2 7 25.97546
3 17 -41.53234
4 19 145.11658
5 21 -73.18515
6 23 113.94388

Data 17 (various data in the state of focusing on a close object)
Wide angle Medium telephoto Object distance 300.0000 300.0000 300.0000
d6 36.9765 11.9226 1.0000
d16 2.8832 6.4117 9.7273
d18 4.0675 3.8086 2.0000
d20 3.0407 3.1072 2.2446
d22 1.6856 13.4482 33.6818

(Numerical example 6)
The zoom lens system of Numerical Example 6 corresponds to Embodiment 6 shown in FIGS. 20A to 20C. The surface data of the zoom lens system of Numerical Example 6 is the data 18, the aspherical data is the data 19, the various data in the infinite focus state is the data 20, and the various data in the close object in-focus state is the data 21. Shown in

Data 18 (surface data)
Surface number rd nd vd
Object ∞
1 67.46590 1.50000 1.83400 37.3
2 22.72740 9.61610
3 -97.75550 1.20000 1.69680 55.5
4 67.09320 2.89810
5 43.39390 4.36810 1.84666 23.8
6 176.13480 Variable
7 * 23.12150 6.67260 1.77200 50.0
8 * -80.46600 0.50000
9 -87.40760 0.90000 1.80518 25.5
10 149.99030 5.56250
11 (Aperture) ∞ 1.00000
12 27.74710 0.80000 1.80610 33.3
13 11.64230 5.63930 1.49700 81.6
14 -96.39190 0.20000
15 39.07800 0.99430 1.84666 23.8
16 73.58310 Variable
17 82.84870 0.60000 1.54814 45.8
18 15.87980 Variable
19 * 89.43000 1.50000 1.64000 19.0
20 -142.89130 Variable
21 -46.22180 0.80000 1.75520 27.5
22 886.81000 Variable
23 -80.39220 4.13680 1.59349 67.0
24 -35.50930 Variable
Image plane ∞

Data 19 (Aspherical data)
7th page
K = 0.00000E + 00, A4 = -4.70300E-06, A6 = 0.00000E + 00
8th page
K = 0.00000E + 00, A4 = 5.36511E-06, A6 = 0.00000E + 00
19th page
K = 0.00000E + 00, A4 = -5.42857E-07, A6 = 1.15640E-07

Data 20 (Various data in infinite focus state)
Wide angle Medium telephoto Focal length 24.72000 44.99970 72.7493
F number 3.60503 4.99576 5.76829
Angle of view 44.47590 25.51220 16.5454
Image height 21.63000 21.63000 21.6300
d6 37.21570 12.24740 1.0000
d16 2.22120 4.47210 6.5258
d18 5.32620 6.01780 4.8002
d20 2.04590 2.60420 2.1000
d22 1.62080 13.78240 33.2078
d24 21.18210 20.68180 21.9756

Zoom lens group data Group Start surface Focal length
1 1 -39.11980
2 7 25.30783
3 17 -35.95389
4 19 86.16198
5 21 -58.15122
6 23 103.60989

Data 21 (various data when in close proximity to the object)
Wide-angle Medium Tele-object distance 300.0000 300.0000 300.0000
d6 37.2157 12.2474 1.0000
d16 2.7701 5.9969 9.2987
d18 4.1984 4.0492 2.0273
d20 2.6249 3.0479 2.1000
d22 1.6208 13.7824 33.2078
d24 21.1821 20.6818 21.9756
(Numerical example 7)
Data 22 (surface data)
Surface number rd nd vd
Object ∞
1 151.47430 2.40000 1.90366 31.3
2 94.77890 8.97120 1.49700 81.6
3 -1538.85890 0.20000
4 95.54070 6.99620 1.43700 95.1
5 1408.22310 Variable
6 188.36590 4.94190 2.00100 29.1
7 -124.52190 1.80000 1.63854 55.4
8 32.65720 6.62800
9 34.39310 4.26250 1.67270 32.2
10 88.69360 1.50000 1.80420 46.5
11 47.88720 5.85180
12 -53.88190 1.50000 1.90366 31.3
13 -170.40170 Variable
14 58.97580 3.42830 1.80420 46.5
15 1228.74110 0.10000
16 34.41080 7.80050 1.49700 81.6
17 -112.43160 6.00000 1.80420 46.5
18 25.75760 4.77550
19 (Aperture) ∞ 2.55860
20 86.08400 1.20000 1.84666 23.8
21 40.47930 5.00620 1.51680 64.2
22 -104.27990 0.20000
23 75.91980 3.04010 1.77250 49.6
24 -228.76060 3.09380
25 -38.78290 1.20000 1.51823 59.0
26 31.40730 8.17840 1.59282 68.6
27 -35.54840 Variable
28 116.99200 2.83470 1.92119 24.0
29 -57.27040 0.70000 1.72342 38.0
30 29.75650 Variable
31 47.66610 3.98820 1.49700 81.6
32 -137.76780 Variable
33 -114.86890 1.30000 1.65844 50.9
34 127.37720 BF
Image plane ∞

Data 23 (various data)
Zoom ratio 3.13642
Wide angle Medium telephoto Focal length 61.8233 105.7396 193.9039
F number 2.91649 2.91649 2.91520
Angle of View 9.9118 5.7838 3.1597
Image height 10.8150 10.8150 10.8150
d5 0.6000 32.4503 62.7047
d13 62.7047 30.8544 0.6000
d27 7.9288 7.6226 2.0000
d30 17.3141 15.7117 27.7502
d32 12.0312 13.9398 7.5240

Zoom lens group data Group Start surface Focal length
1 1 160.75342
2 6 -55.86637
3 14 53.11418
4 28 -79.17536
5 31 71.76726
6 33 -91.53762

Data 24 (various data when in close proximity with object)
Zoom ratio 3.13642
Wide angle Medium Telephoto object distance 1000.0000 1000.0000 1000.0000
d5 0.6000 32.4503 62.7047
d13 62.7047 30.8544 0.6000
d27 9.1620 11.2958 12.1220
d30 14.7987 8.8362 6.7701
d32 13.3133 17.1420 18.3820
Table 1 below shows corresponding values for each condition in the zoom lens system of each numerical example.

  (Corresponding value of condition)

  The zoom lens system according to the present disclosure is applicable to a digital still camera, a digital video camera, a mobile phone device camera, a PDA (Personal Digital Assistance) camera, a surveillance camera in a surveillance system, a Web camera, an in-vehicle camera, etc. It is particularly suitable for a photographing optical system that requires high image quality, such as a digital still camera system and a digital video camera system.

  The zoom lens system according to the present disclosure can be applied to an interchangeable lens apparatus equipped with an electric zoom function for driving a zoom lens system with a motor, which is provided in a digital video camera system, among the interchangeable lens apparatuses according to the present disclosure. Is possible.

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group G6 6th lens group G7 7th lens group G8 8th lens group L1 1st lens element L2 2nd lens element L3 3rd lens element L4 4th lens element L5 5th lens element L6 6th lens element L7 7th lens element L8 8th lens element L9 9th lens element L10 10th lens element L11 11th lens element L12 12th lens element L13 13th lens element L14 14th lens element L15 15th lens element L16 16th lens element L17 17th lens element L18 18th lens element L19 19th lens element L20 20th lens element L21 21st lens element L22 22nd lens element L23 23rd lens element A Aperture stop VA Variable beam stop S image surface 100 lens-interchangeable digital camera system 101 camera body 102 image sensor 103 monitor 104 camera mount section 201 interchangeable lens apparatus 202 a zoom lens system 203 barrel 204 lens mount

Claims (20)

A zoom lens system having a plurality of lens groups each composed of at least one lens element,
In order from the object side to the image side, a front group including a first focus lens group having a negative power and a rear group including a second focus lens group having a positive power are provided.
The first focus lens group and the second focus lens group move along the optical axis during zooming from the wide-angle end to the telephoto end;
When focusing from an infinitely focused state to a close object focused state, the first focus lens group and the second focus lens group move to perform focusing, and the following conditional expressions (1) and (2) Zoom lens system that satisfies the requirements.
−20 <β1t / β1w × β2t / β2w <20 (1)
0.25 <| f1 / f2 | <1.30 (2)
here,
β1t: lateral magnification at the telephoto end of the first focus lens group β1w: lateral magnification at the wide-angle end of the first focus lens group β2t: lateral magnification at the telephoto end of the second focus lens group β2w: of the second focus lens group Horizontal magnification at wide angle end f1: Focal length of first focus lens group f2: Focal length of second focus lens group An aperture stop,
The first focus lens group and the second focus lens group are disposed on the image side of the aperture stop.
The zoom lens system according to claim 1. When focusing from an infinitely focused state to a close object focused state, the first focus lens group moves along the optical axis toward the image side, and the second focus lens group moves toward the object side along the optical axis.
The zoom lens system according to claim 1 or 2. The first focus lens group moves in a convex manner toward the image side at the time of zooming from the wide-angle end to the telephoto end.
The zoom lens system according to claim 1. The second focus lens group moves closer to the group adjacent to the image side at the time of zooming from the wide-angle end to the telephoto end.
The zoom lens system according to claim 1. Among the lens elements constituting the second focus lens group, the lens element satisfying conditional expression (3) is included.
The zoom lens system according to claim 1.
νp2 <30 (3)
here,
νp2: Abbe number of the lens element having the strongest positive power among the lens elements constituting the second focus lens group The second focus lens group is composed of one lens element having positive power.
The zoom lens system according to claim 1. The first focus lens group includes a single lens element having a positive power and a single lens element having a negative power, and satisfies the conditional expression (4).
The zoom lens system according to claim 1.
νp1 <30 (4)
here,
νp1: Abbe number of the lens element having the strongest positive power among the lens elements constituting the first focus lens group The first focus lens group includes, in order from the object side to the image side, a cemented lens of a single lens element having a positive power and a single lens element having a negative power.
The zoom lens system according to claim 1. The zoom lens system according to claim 1, wherein the zoom lens system satisfies the conditional expression (5).
mf2w / mf1w> mf2t / mf1t (5)
here,
mf2w: the amount of movement of the second focus lens group when focusing on an object at an arbitrary distance from the infinite focus state at the wide angle end mf1w: focusing on an object at an arbitrary distance from the infinite focus state at the wide angle end The amount of movement of the first focus lens group at the time mf2t: At the telephoto end, the amount of movement of the second focus lens group when focusing on the object at an arbitrary distance from the infinitely focused state mf1t: Infinite focus at the telephoto end The amount of movement of the first focus lens group when focusing on an object at an arbitrary distance from the state The front group includes a first lens group positioned closest to the object side,
The first lens group has a positive power;
The zoom lens system according to claim 1. The first lens group is fixed with respect to the image plane when zooming from the wide-angle end to the telephoto end.
The zoom lens system according to claim 11. Between the first lens group and the aperture stop, there are two lens groups that move along the optical axis when zooming from the wide-angle end to the telephoto end.
The zoom lens system according to claim 11. The front group includes a first lens group having a positive power, a second lens group having a negative power, and a third lens group having a positive power in order from the object side to the image side on the object side of the first focus lens group. ,
The zoom lens system according to claim 1. The third lens group includes a single lens element having a positive power.
The zoom lens system according to claim 14. The lens group immediately on the object side of the first focus lens group includes, in order from the object side to the image side, a first sub lens group having a positive power, an aperture stop, and a second sub lens group having a negative power. A third sub-lens group having a positive power for performing image blur correction by moving in a direction perpendicular to the optical axis, and a fourth sub-lens group.
The zoom lens system according to claim 14 or 15. A variable beam stop having a diameter that changes during zooming from the wide-angle end to the telephoto end between the third sub-lens group and the fourth sub-lens group;
The zoom lens system according to claim 16. The third sub-lens group includes a cemented lens of a lens element having negative power, a lens element having positive power, and a positive single lens element in order from the object side to the image side.
The zoom lens system according to claim 16.   The zoom lens system according to claim 1, and a lens mount that can be connected to a camera body including an image sensor that receives an optical image formed by the zoom lens system and converts the optical image into an electrical image signal. Interchangeable lens device.   An interchangeable lens device according to claim 19, and an image sensor that is detachably connected to the interchangeable lens device via a camera mount and receives an optical image formed by the zoom lens system and converts it into an electrical image signal. A camera system comprising: a camera body including:

Images