JP2006220795A - Zoom lens device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a zoom lens device achieving high zoom magnification and miniaturization in an optical axis direction. <P>SOLUTION: A cam barrel 16 is rotated around a fixed barrel 17, and a middle barrel 13 is extended while rotating by the rotation of the cam barrel 16. A front barrel 11 holding a first lens group 18 is extended to the most separate position from an image forming surface by making the middle barrel 13 advance to/retreat from the fixed barrel 17 and making the front barrel 11 advance to/retreat from the middle barrel 13. A second lens frame 12 is extended by the cam of the middle barrel 13. A fourth lens frame 15 is made to advance/retreat by a motor 35 provided in a third lens frame 14. The rotation of the third and the fourth lens frames 14 and 15 is stopped by a guide means provided in the fixed barrel 17. The third lens frame 14 stops the rotation of the second lens frame 12 on its periphery, and the second lens frame 12 stops the rotation of the front barrel 11 on its periphery. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention supports four lens groups movably in the optical axis direction between a retracted position housed in a fixed cylinder and a photographing position extended toward the subject side, and the second lens group at the photographing position. The zoom lens apparatus performs zooming by moving the zoom lens and moving the fourth lens group to adjust the focus.

  Conventionally, the first to fourth lens groups arranged in order from the subject side are supported so as to be movable in the optical axis direction, and focus adjustment is performed by moving the second lens group in the optical axis direction. A zoom lens device is known in which focus adjustment is performed by moving the lens in the optical axis direction (Patent Document 1).

  This zoom lens device includes a fixed cylinder, a cam cylinder, a movable cylinder, second to fourth lens frames, and the like. The first lens group is fixed to the movable cylinder. The cam cylinder is rotatably supported on the outer periphery of the fixed cylinder in a state in which movement in the optical axis direction is prevented, and by rotating, the cam provided on the inner periphery and the linear guide provided on the fixed cylinder are cooperated. By movement, the movable cylinder, the second lens frame, and the third lens frame are moved in the optical axis direction.

  In addition, a plurality of guide bars are attached to the fixed cylinder in parallel with the optical axis direction by L-shaped brackets. Each guide rod supports the third to fourth lens frames so as to be able to advance and retreat in a state where rotation is stopped. The third lens frame is guided by a guide rod, and is advanced and retracted in the optical axis direction by a cam mechanism provided between the third lens frame and the intermediate cylinder. The fixed cylinder is provided with a lead screw parallel to the optical axis direction and a focusing motor attached to the bracket. A female screw portion provided on the fourth lens frame is engaged with the lead screw, and the fourth lens frame moves in the optical axis direction when the driving of the focusing motor is transmitted to the lead screw.

  In such a zoom lens configuration, the first lens group acts as a fixed lens, the second lens group acts as a variable power lens, the third lens group acts as a relay lens, and the fourth lens group focuses. It functions as a lens, and only the second lens group moves during zooming. Then, when the camera is turned off, the camera is moved to the retracted position. At this retracted position, the third and fourth lens groups are brought close to the imaging plane inside the fixed cylinder, and the first and second lens groups are placed in the internal space of the fixed cylinder between the tip of the fixed cylinder and the third lens group. The first to fourth lens frames are housed inside the fixed cylinder so that the lens enters.

For this reason, each cam provided on the cam cylinder is provided with a displacement for moving the movable cylinder, the second lens frame, and the third lens frame to the retracted position, and the lead lens is provided with the fourth lens group. In addition to the length for moving to the in-focus position for each zoom position, the length for moving the fourth lens group to the retracted position is provided.
JP 2003-295031 A

  However, the lead screw becomes longer in order to move the fourth lens group to the retracted position. In addition, when the zoom magnification is set to a high magnification, it is necessary to take a long movement amount for adjusting the focus. For this reason, a fixed cylinder having a length that covers the lead screw at the retracted position is required, and as a result, the camera body is thick.

  In order to increase the zoom magnification, the first lens group needs to be separated from the image plane as much as possible. Since the moving cylinder is advanced and retracted by a cam provided on the cam cylinder and a linear guide provided on the fixed cylinder, it is necessary to increase the displacement of the cam in the optical axis direction and lengthen the linear guide in the optical axis direction. There is. If comprised in this way, the length of the optical axis direction of a cam cylinder will become long, and, thereby, the compactization in the optical axis direction of the zoom lens apparatus was inhibited.

  In the present invention, in view of the above circumstances, a zoom that moves the second lens group of the first to fourth lens groups in the optical axis direction at the time of zooming and moves the fourth lens group in the optical axis direction at the time of focusing. An object of the present invention is to provide a zoom lens device that can shorten the length in the optical axis direction at the retracted position.

  In order to achieve the above object, in the present invention, the first to fourth lens holding members that respectively hold the first to fourth lens groups arranged in order from the subject side are fixed to the retracted position in which the first to fourth lens holding members are housed in the fixed cylinder. The second lens holding member is moved in the optical axis direction to change the magnification at the shooting position, and the fourth lens holding member is moved to the optical axis at the time of focusing. In the zoom lens apparatus that moves in the direction, moving means that moves the fourth lens holding member forward and backward together with the third lens holding member and moves the fourth lens holding member so that the distance from the third lens holding member changes. The third lens holding member is provided.

  The moving means includes a focusing motor and a screw shaft that engages with a female screw provided on the fourth lens holding member and rotates by driving the motor to move the fourth lens holding member. Is desirable.

  The third and fourth lens holding members are preferably supported so as to be able to advance and retreat in the optical axis direction in a state in which the fourth lens holding member is prevented from rotating by guide means provided inside the fixed cylinder.

  In another invention, the cam mechanism provided in the cam cylinder and the fixed cylinder moves forward and backward in the optical axis direction while rotating with respect to the fixed cylinder as the cam cylinder rotates. An intermediate cylinder for moving the first and second lens holding members forward and backward in the optical axis direction by engaging with each cam between the two lens holding members; and the cam cylinder and the third lens holding frame. A cam member provided to move the third lens holding member forward and backward in the direction of the optical axis as the cam barrel rotates; provided on the third lens holding member; and the fourth lens holding member as the third lens holding member. And a moving means for moving the fourth lens holding member forward and backward so that the distance from the third lens holding member changes; and provided between the second lens holding member and the third lens holding member. The third lens holder A first rotation preventing means for allowing movement of the member in the optical axis direction and for preventing rotation; provided between the first lens holding member and the second lens holding member; Second rotation stopping means for allowing movement in the optical axis direction and stopping rotation.

  According to the present invention, since the focusing means for moving the fourth lens holding member is provided in the third lens holding member, the fourth lens holding member can be moved together with the third lens holding member. it can. Thereby, the length for moving the fourth lens holding member to the retracted position in the length of the screw shaft can be omitted, so that the length of the fixed tube in the optical axis direction can be shortened.

  According to another invention, the intermediate lens is provided to increase the moving distance of the first lens holding member, and the second lens holding member is rotated by the third lens holding member that is rotationally stopped by the guide means of the fixed cylinder. Since the second lens holding member is configured to stop the rotation of the first lens holding member, the moving distance of the first lens holding member is lengthened to increase the zoom magnification, The length in the optical axis direction can be shortened.

  As shown in FIG. 1, the zoom lens apparatus 10 according to an embodiment of the present invention includes a front cylinder 11, a second lens frame 12, an intermediate cylinder 13, a third lens frame 14, a fourth lens frame 15, and a cam cylinder 16. And the fixed cylinder 17. The front tube 11 has a first lens group 18, the second lens frame 12 has a second lens group 19, the third lens frame 14 has a third lens group 20, and the fourth lens frame 15 has The fourth lens group 21 is held. Further, the third lens frame 20 incorporates a shutter unit 22 serving as an aperture that opens and closes shutter blades between the second lens group 19 and the third lens group 20. The front cylinder 11 constitutes a first lens holding member, and the second to fourth lens frames 12 to 15 constitute second to fourth lens holding members, respectively.

  The fixed cylinder 17 includes a cylinder portion 23 and a substrate 24 fixed to the base end portion of the cylinder portion 23, and is attached within the outline of the camera body. This lens device 10 is incorporated in an electronic camera. An imaging element 25 is attached on the axis of the imaging optical axis (hereinafter referred to as “optical axis”) 10 a of the substrate 24.

  In the lens apparatus 10, the cam cylinder 16 reverses on the outer periphery of the cylinder portion 23 in synchronization with the operation of turning off the power of the electronic camera, and the lens apparatus 10 is in the retracted position state shown in FIG. At the retracted position, the front cylinder 11, the second lens frame 12, the intermediate cylinder 13, the third lens frame 14, the fourth lens frame 15, and the cam cylinder 16 are all within the fixed cylinder 17, that is, within the contour of the camera body. Stored. When the power is turned on, the cam cylinder 16 is rotated forward from the retracted position to the wide position shown in FIG. 4 through the tele position shown in FIG.

  Photographing is performed at any zoom position between the wide position and the tele position by operating the zoom button. The electronic camera drives the shutter unit 22 in synchronization with the full pressing operation of the shutter button. Subject light transmitted through the first to fourth lens groups 18 to 21 forms an image on the light receiving surface of the image sensor 25, and the image sensor 25 generates an image signal corresponding to the imaged subject image. As shown in FIG. 5, the first to fourth lens groups 18 to 21 are arranged side by side from the subject side, and the second lens group 19 is moved in the direction of the optical axis 10a to change the magnification. The focus is adjusted by moving the fourth lens group 21 in the direction of the optical axis 10a at each zoom position. The first lens group 18 is a movement amount obtained by combining the movement amount of the intermediate cylinder 13 with respect to the fixed cylinder 17 and the movement amount of the front cylinder 11 with respect to the intermediate cylinder 13, and therefore is more than the remaining three lens groups 19 to 21. The amount of movement in the optical axis direction with respect to the rotation of the cam cylinder 16 is the largest.

  The fixed cylinder 17 supports the third and fourth lens frames 14 and 15 so as to be movable in the direction of the optical axis 10a while preventing rotation inside the cylinder portion 23. As shown in FIG. 6, two guide bars 27 and 28 are attached to the substrate 24. Each guide rod 27, 28 is supported by L-shaped support plates 29, 30 attached at one end to the substrate 24 and the other end extending from the substrate 24 in the direction of the optical axis 10a, with the optical axis 10a as the center. Are fixed at different positions in the circumferential direction and parallel to the optical axis 10a. The third and fourth lens frames 14 and 15 are provided with bearing portions 31 and 32 that engage with the guide rods 27 and 28 and fork portions 33 and 34 for rotation prevention, respectively. The guide rods 27 and 28 constitute guide means.

  A focusing motor 35 is fixed to the outer periphery of the third lens frame 14. The output shaft of the motor 35 is a screw shaft 36 extending from the third lens frame 14 toward the image plane. The screw shaft 36 engages with a female screw portion 37 provided on the fourth lens frame 15. ing. The motor 35 is driven to move the fourth lens frame 15 relative to the third lens frame 14 in the direction of the optical axis 10a. The screw shaft 36 is necessary for adjusting the focus at each zooming position, that is, the length by which the fourth lens group is moved 15 times between the approach position approaching the third lens group 14 and the separation position away from the third lens group 14. The length depends on the amount of movement. Since the screw shaft 36 is engaged with the female screw portion 37 of the fourth lens frame 15, the fourth lens frame 15 moves together with the third lens frame 14. For this reason, as described in the prior art, the length of the fourth lens frame 15 of the screw shaft 36 that is moved from the retracted position to the photographing position, compared to the case where the focusing motor is provided in the fixed cylinder. Therefore, the length of the lens device 10 in the direction of the optical axis 10a can be shortened. The motor 35, the screw shaft 36, and the female screw portion 37 constitute moving means. And as a moving means, it is not restricted to these structures, For example, you may use the moving means driven linearly.

  The third lens frame 14 is provided with a fourth cam follower 38 and rectilinear guide ribs 39 to 41 protruding from the outer periphery. The fourth cam follower 38 protrudes at one circumferential position centered on the optical axis 10a. The rectilinear guide ribs 39 to 41 extend in the direction of the optical axis 10a at three positions in the circumferential direction.

  In the second lens frame 12, as shown in FIG. 7, guide grooves 42 to 44 are formed at three positions on the inner periphery. The straight guide ribs 39 to 41 engage with the guide grooves 42 to 44, respectively. Thus, the third lens frame 14 supports the second lens frame 12 so as to be movable in the direction of the optical axis 10a while stopping rotation. The guide grooves 42 to 44 and the rectilinear guide ribs 39 to 41 constitute first rotation stopping means. These guide means may be configured with the concavities and convexities reversed.

  The second lens frame 12 is provided with rectilinear guide protrusions 45 to 47 at three positions on the outer periphery of the front end, and second cam followers 48 to 50 at three positions on the rear end. As shown in FIG. 8, the three rectilinear guide protrusions 45 to 47 are respectively engaged with rectilinear guide grooves 51 to 53 provided on the inner periphery of the front cylinder 11, and the second lens frame 12 rotates the front cylinder 11. While being stopped, it is supported so as to be movable in the direction of the optical axis 10a. The front tube 11 holds the first lens group 18 on the subject side, and has a U-shaped cross section with the open side facing the image plane. The second lens frame 12 enters the inside from the imaging plane side of the front tube 11. Inside the front tube 11, a space for moving the second lens frame 12 is provided after the first lens group 18. Note that the rectilinear guide protrusions 45 to 47 and the rectilinear guide grooves 51 to 53 constitute second rotation stopping means. As these guide means, it is good also as a structure which reversed the unevenness | corrugation.

  The three second cam followers 48 to 50 are respectively engaged with the three second cam grooves 57 to 59 provided on the inner periphery of the intermediate cylinder 13 through the notches 54 to 56 provided in the front cylinder 11. Further, the first cam followers 60 to 62 provided at three positions on the outer periphery of the front cylinder 11 are engaged with three first cam grooves 63 to 65 provided on the inner periphery of the intermediate cylinder 13. As shown in FIG. 9, the intermediate cylinder 13 rotates on the outer periphery of the front cylinder 11 and moves the front cylinder 11 toward the subject side in accordance with the displacement of the first cam grooves 63 to 65 in the direction of the optical axis 10 a. A position where the second lens frame 12 is moved closer to the front tube 11 in accordance with the displacement in the direction of the optical axis 10a of the second cam grooves 57 to 59 while being moved between the position where it is extended and the position where it is retracted. And move away from the position.

  As shown in FIG. 10, a cylinder portion 23 constituting the fixed cylinder 17 is disposed on the outer periphery of the intermediate cylinder 13, and a cam cylinder 16 is rotatably disposed on the outer periphery of the cylinder portion 23. The intermediate cylinder 13 is provided with third cam followers 66 to 68 at three positions on the outer periphery, and the three third cam followers 66 to 68 are third cam openings provided at three positions on the outer periphery of the cylinder portion 23. 69 to 71 are engaged with linear grooves 72 to 74 provided at three positions on the inner circumference of the cam cylinder 16. The fourth cam follower 38 provided in the third lens frame 14 passes through the rear end of the intermediate cylinder 13 and the cutout portion 75 of the cylinder portion 23, and a fourth cam groove provided in the inner periphery of the cam cylinder 16. 76 is engaged. The fourth cam follower 38 and the fourth cam groove 76 constitute a cam member. The third cam followers 66 to 68, the third cam openings 69 to 71, and the straight grooves 72 to 74 constitute a cam mechanism.

  The cam cylinder 16 is sandwiched between the flange 77 provided at the front end of the cylinder portion 23 and the substrate 24 so as not to move in the direction of the optical axis 10a. It is rotated when the drive of is input. When the cam cylinder 16 rotates, the intermediate cylinder 13 moves in the direction of the optical axis 10a by the cooperation of the third cam openings 69 to 71 and the rectilinear grooves 72 to 74, and the third lens frame 14 also has the guide rods 27 and 28. Therefore, the fourth cam groove 76 moves in accordance with the displacement in the direction of the optical axis 10a.

  As shown in FIG. 11, the third cam openings 69 to 71 are cam surfaces 69 a for moving the third cam followers 66 to 68, that is, the intermediate cylinder 13 in the optical axis direction in cooperation with the rectilinear grooves 72 to 74. ~ 71a. These cam surfaces 69a to 71a have a shape that extends the intermediate tube 13 from the retracted position to the tele position and does not move the intermediate tube 13 in the direction of the optical axis 10a between the tele position and the wide position. ing. The fourth cam follower 38 is inserted through the notch 75.

  As shown in FIG. 12, the fourth cam groove 76 has a cam surface 76a for moving the fourth cam follower 38, that is, the third lens frame 14 in the direction of the optical axis 10a. The cam surface 76a extends the third lens frame 14 from the retracted position to the tele position, and keeps the third lens frame 14 at the extended position between the tele position and the wide position. The shape does not move in the direction of. The three rectilinear grooves 72 to 74 are formed to extend in the direction of the optical axis 10a in order to allow movement of the third cam followers 66 to 68 in the direction of the optical axis 10a. In order to make the cam groove 76, it is formed in the unequal position of the circumferential direction centering on the optical axis 10a.

  As shown in FIG. 13, the three first cam grooves 63 to 65 have three first cam followers 60 to 62, that is, cam surfaces 63a to 65a for moving the front cylinder 11 in the direction of the optical axis 10a. is doing. The cam surfaces 63a to 65a extend the front cylinder 11 from the retracted position to the tele position, and keep the front cylinder 11 of the optical axis 10a between the tele position and the wide position. The shape does not move in the direction.

  The second cam grooves 57 to 59 have three second cam followers 48 to 50, that is, cam surfaces 57a to 59a for moving the second lens frame 12 in the direction of the optical axis 10a. These cam surfaces 57a to 59a retract the second lens frame 12 to the intermediate tube 13 from the retracted position to the tele position, and to the intermediate tube 13 between the tele position and the wide position. The second lens frame 12 is shaped to move in the direction of the optical axis 10a.

  The operation of the above configuration will be briefly described. As shown in FIG. 2, the initial state of the lens apparatus 10 is a retracted state in which the front cylinder 11, the intermediate cylinder 13, and the second to fourth lens frames 12, 14, and 15 are housed in the fixed cylinder 17. It has become. When the power of the camera is turned on, the zooming motor is driven by a predetermined amount, and this drive is input to the gear portion 79, whereby the cam cylinder 16 is rotated forward by a predetermined amount. When the cam cylinder 16 rotates, the intermediate cylinder 13 is rotated with respect to the fixed cylinder 17 by the cooperation of the rectilinear grooves 72 to 74 and the third cam openings 69 to 71 of the fixed cylinder 17. Since the front cylinder 11 is prevented from rotating by the second lens frame 12, the front cylinder 11 is extended relative to the intermediate cylinder 13 by the displacement of the first cam grooves 63 to 65 according to the rotation of the intermediate cylinder 13. Further, since the second lens frame 12 is prevented from rotating by the third lens frame 14, the second lens frame 12 is extended with respect to the intermediate cylinder 13 in accordance with the displacement of the second cam grooves 57 to 59 according to the rotation of the intermediate cylinder 13. It is.

  Further, since the third lens frame 14 is prevented from rotating by the two guide rods 27 and 28, the third lens frame 14 is extended inside the fixed cylinder 17 by the displacement of the fourth cam groove 76 according to the rotation of the cam cylinder 16. . Since the third lens frame 14 is engaged with the screw shaft 36 of the focusing motor 35 and the female screw portion 37 of the fourth lens frame 15, the fourth lens frame 15 is connected to the third lens frame 14. It is paid out together. Then, the focusing motor 35 is driven between the retracted position and the telephoto position, and the fourth lens frame 15 is moved to the origin position separated from the third lens frame 14.

  As a result, when the camera is turned on, the lens device 10 passes through the tele position and enters the wide position shown in FIG. When the zoom operation is performed with the zoom button toward the tele position, the camera reverses the zooming motor, and the lens device 10 is in the tele position. The first lens group 18 is a fixed lens group that does not move during zooming, and the third lens group 20 functions as a relay lens and the fourth lens group 21 functions as a focus lens. At the time of zooming between positions, only the second lens group 19 acting as a zoom lens moves. As a shooting position used for shooting, any zooming position between the wide position and the tele position can be used.

  Distance measurement is performed in response to the half-pressing operation of the shutter button, and the focus motor 35 is driven in accordance with the subject distance information obtained from the distance measurement. As a result, the fourth lens frame 15 moves to a position approaching the third lens frame 14, and the fourth lens group 21 is set at the in-focus position corresponding to the zoom position and subject distance at that time. The fourth lens frame 15 is returned to the original position by driving the motor 35 when the half-pressing operation is stopped or after completion of imaging.

  When the power of the camera is turned off, the zooming motor is rotated in the reverse direction, and the cam cylinder 16 is rotated in the reverse direction so that the lens apparatus 10 is in the retracted position. Then, between the tele position and the retracted position, the focusing motor 35 is driven to move the fourth lens frame 15 to a position approaching the third lens frame 14. As a result, the first to fourth lens groups 18 to 21 are housed in the fixed cylinder 17 in a state in which they are close to each other.

  The first lens group 18 moves in the direction of the optical axis 10 a by combining the advance and retreat of the intermediate cylinder 13 with respect to the fixed cylinder 17 and the displacement of the first cam grooves 63 to 65 according to the rotation of the intermediate cylinder 13. The second lens group 19 moves in the direction of the optical axis 10a by combining the advance and retreat of the intermediate tube 13 and the displacement of the second cam grooves 57 to 59 according to the rotation of the intermediate tube. The third lens group 20 is configured to move within the fixed cylinder 17 by the displacement of the fourth cam groove 76 provided in the fixed cylinder 17, and the fourth lens group 21 is moved together with the third lens group 20. It is configured to move to. The fourth lens group 21 is configured to move in the direction of the optical axis 10 a with respect to the third lens group 20 by driving the focusing motor 35.

  Then, the rotation of the second lens frame 12 is stopped at the outer periphery of the third lens frame 20 stopped by the guide rods 27 and 28, and the rotation of the front tube 11 is stopped at the outer periphery of the second lens frame 12. Thereby, even if the movement amount of the first lens group 18 is increased in order to increase the zoom magnification, the length along the direction of the optical axis 10a of the cam cylinder 16 can be shortened. The apparatus 10 can be made compact in the direction of the optical axis 10a.

  In the above-described embodiment, the example applied to the electronic camera has been described. However, the present invention is not limited to this and can be applied to a video camera and a photographic camera.

It is a disassembled perspective view which shows the outline of the zoom lens apparatus of this invention. It is sectional drawing which shows the retracted state of a zoom lens apparatus. It is sectional drawing which shows the tele state of a zoom lens apparatus. It is sectional drawing which shows the wide state of a zoom lens apparatus. It is a graph which shows the movement locus | trajectory of the 1st thru | or 4th lens group which advances / retreats to a wide position through a tele position from a retracted position. It is a disassembled perspective view which shows the principal part of a structure of the guide means which guides the 3rd and 4th lens frame. It is a disassembled perspective view which shows the principal part of the structure which a 3rd lens frame stops rotation of a 2nd lens frame. It is a disassembled perspective view which shows the principal part of the structure which a 2nd lens frame stops rotation of a front cylinder. It is a disassembled perspective view which shows the principal part of the structure of each cam engagement with a front cylinder and a 2nd lens frame, and an intermediate | middle cylinder. It is a disassembled perspective view which shows the principal part of the structure of a cam engagement with an intermediate | middle cylinder and a 4th lens frame, and a cam cylinder. It is an expanded view which shows the inner surface of a fixed cylinder. It is an expanded view which shows the inner surface of a cam cylinder. It is an expanded view which shows the inner surface of an intermediate | middle cylinder.

Explanation of symbols

11 Front cylinder 12 Second lens frame 13 Intermediate cylinder 14 Third lens frame 15 Fourth lens frame 16 Cam cylinder 27, 28 Guide rod 35 Focusing motor 36 Screw shaft

Claims (5)

With respect to the retracted position and the fixed cylinder, the first to fourth lens holding members that respectively hold the first to fourth lens groups arranged in order from the subject side are stored inside the fixed cylinder and close to the imaging surface side. The second lens holding member is moved in the direction of the optical axis to change the magnification at the shooting position, and the fourth lens holding member is lighted at the time of focusing. In a zoom lens device that moves in the axial direction,
The third lens holding member is provided with moving means for moving the fourth lens holding member so that the fourth lens holding member is moved forward and backward together with the third lens holding member and the distance from the third lens holding member is changed. A zoom lens device characterized by that. The moving means includes a focusing motor and a screw shaft that engages with a female screw provided on the fourth lens holding member and rotates by driving the motor to move the fourth lens holding member. 2. The zoom lens apparatus according to claim 1, wherein the zoom lens apparatus is provided.   3. The zoom according to claim 2, further comprising guide means provided inside the fixed cylinder and supporting the third and fourth lens holding members so as to be able to advance and retreat in the optical axis direction in a state where the third and fourth lens holding members are prevented from rotating. Lens device. First to fourth lens holding members that respectively hold first to fourth lens groups arranged in order from the subject side;
A fixed cylinder that houses the first to fourth lens holding members when retracted, and a cam cylinder that is supported only rotatably relative to the fixed cylinder;
The guide means provided inside the fixed cylinder supports the third and fourth lens holding members so as to be able to advance and retreat in the optical axis direction in a state in which the rotation is stopped.
In the zoom lens device that rotates the cam cylinder to extend the first to fourth lens holding members from the retracted position toward the shooting position used for shooting,
The cam mechanism provided in the cam cylinder and the fixed cylinder advances and retreats in the optical axis direction while rotating with respect to the fixed cylinder as the cam cylinder rotates, and between the first and second lens holding members. An intermediate cylinder for advancing and retracting the first and second lens holding members in the optical axis direction by engaging with each of the cams;
A cam member that is provided on the cam cylinder and the third lens holding member and moves the third lens holding member forward and backward in the optical axis direction as the cam cylinder rotates;
Provided on the third lens holding member, the fourth lens holding member is moved forward and backward together with the third lens holding member, and the fourth lens holding member is moved so that the distance from the third lens holding member is changed. Transportation means;
First rotation stopping means provided between the second lens holding member and the third lens holding member, allowing movement of the third lens holding member in the optical axis direction and stopping rotation;
Second rotation stopping means provided between the first lens holding member and the second lens holding member, allowing the movement of the first lens holding member in the optical axis direction and stopping rotation. A zoom lens device characterized by that. The moving means includes a focusing motor and a screw shaft that engages with a female screw provided on the fourth lens holding member and rotates by driving the motor to move the fourth lens holding member. 5. The zoom lens apparatus according to claim 4, wherein the zoom lens apparatus is provided.

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