JP2010271524A - Lens barrel and optical apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel in which a plurality of spherical cam followers provided in the moving cam ring side are easily incorporated in cam grooves in a cam ring and which moves the moving cam rings in the optical axis direction. <P>SOLUTION: In a lens barrel having one or more cam rings which move in the optical axis direction, a plurality of cam grooves for moving holding frames that hold moving lens groups to move, are provided inside of one cam ring of the one or more cam rings. In the moving holding frames, a plurality of spherical cam followers, each of which is engaged with each of the plurality of cam grooves of the cam ring, are held via energizing members which energize the cam followers to the direction to engage with the cam grooves. In the cam ring, the parts where the plurality of cam followers are incorporated in the plurality of cam grooves are comprised of a shape having level difference in the optical axis direction, so that when the other cam follower is incorporated in the cam groove, the cam follower previously incorporated in the cam groove has been already engaged and held with the cam groove and the moving holding flame. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens barrel and an optical apparatus having the same, and is suitable for a still camera, a digital still camera, a video camera, and the like.

  Conventionally, in an optical apparatus such as a digital camera, when taking a picture, a part of a lens barrel is extended from the camera body (shooting apparatus body) to take a picture. When carrying without taking a picture (when not taking a picture), a so-called collapsible lens barrel is used in which a part of the lens barrel is housed in the camera body to shorten the overall length and improve portability. . Among these, a lens barrel (imaging device) having a zoom function is known (Patent Document 1). In the lens barrel of Patent Document 1, a cam groove for moving a lens is provided in the movable cam ring, and a cam groove for collapsing is provided in the fixed cylinder. The movable cam ring is driven to rotate and rotated along the retracting cam groove of the fixed cylinder to move in the optical axis direction. A configuration is disclosed in which zooming is performed by moving a moving holding frame that holds a movable lens in the optical axis direction along a lens moving cam groove by rotation of a moving cam ring.

  In the above conventional example, each moving cam ring is generally moved in the optical axis direction by fitting with a conical cam follower with respect to each cam groove. At this time, a lens barrel having a configuration in which a spherical cam follower is used for fitting with a cam groove for the purpose of smooth operation of the movable cam ring is known (Patent Document 2).

JP 2001-324663 A JP 2002-236247 A

  In a lens barrel that uses a spherical cam follower as a cam follower that fits in the cam groove to move the moving cam ring, biasing means such as a spring property of the barrel (moving cam ring) or a spring provided separately is provided. It is used to prevent looseness of the moving cam ring. In this configuration, it is difficult to fix the cam follower to the cam groove of the moving cam ring like a conical cam follower, and it is difficult to incorporate the cam follower.

  The present invention can easily incorporate a plurality of spherical cam followers provided on the moving cam ring side into the cam groove of the cam ring, and a lens barrel suitable for moving the moving cam ring in the optical axis direction. It is an object to provide an optical apparatus having

  The lens barrel of the present invention is a lens barrel having one or more cam rings that shift in the optical axis direction, and one cam ring of the one or more cam rings holds a moving lens group inside thereof. A plurality of cam grooves for moving the movable holding frame are provided, and a plurality of spherical cam followers that respectively fit in the plurality of cam grooves of the cam ring engage with the cam groove. The cam ring has a portion that incorporates the plurality of cam followers into the plurality of cam grooves. When the other cam follower is incorporated into the cam groove, the cam ring is preceded by the cam groove. The incorporated cam follower has a step shape in the optical axis direction so as to be already fitted and held by the cam groove and the movable holding frame.

  In addition, the lens barrel of the present invention is a lens barrel having a plurality of cam rings. Among the plurality of cam rings, the fixed fixed cam ring has a movable cam ring that can move in the optical axis direction inside thereof. The moving cam ring is provided with a biasing member that biases the moving cam ring in a direction in which a plurality of spherical cam followers that fit into the cam groove of the fixed cam ring engage with the cam groove. The fixed cam ring includes a portion that incorporates the plurality of cam followers into the plurality of cam grooves, and a cam follower that is incorporated into the cam groove in advance when the other cam follower is incorporated into the cam groove. It is characterized by having a step shape in the optical axis direction so as to be already fitted and held by the cam groove and the moving cam ring.

  According to the present invention, there is provided a lens barrel capable of easily incorporating a plurality of spherical cam followers provided on the moving cam ring side into the cam groove of the cam ring and moving the moving cam ring in the optical axis direction. can get.

The exploded perspective view of Example 1 of the present invention. Sectional drawing of Example 1 of this invention 1 is a developed view of the moving cam ring of FIG. 1 is a development view of the fixed cam ring of FIG. The figure which shows embodiment from which the biasing form which biases and positions the cam follower of the spherical body of FIG. 1 differs. Fig. 3 is a development view of a fixed cam ring in the second embodiment of the present invention

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The lens barrel of the present invention is a zoom lens barrel having a variable overall length having one or more cam rings that shift in the optical axis direction. Of the one or more cam rings, one cam ring is rotatable, and a plurality of cam grooves for moving a moving holding frame for holding the moving lens group are provided inside thereof. The movable holding frame holds a plurality of spherical (spherical) cam followers, which are respectively fitted in the plurality of cam grooves of the cam ring, via a biasing member such as a spring that biases the cam follower in a direction to engage with the cam groove. Yes. The cam ring has the following shape in which a plurality of cam followers are assembled into a plurality of cam grooves. That is, among the plurality of cam followers, when the other cam follower is incorporated into the cam groove, the cam follower previously incorporated into the cam groove is fitted and held by the cam groove and the movable holding frame in the optical axis direction or the rotation direction. It consists of a step shape. In addition, the lens barrel of the present invention is a zoom lens barrel with a variable overall length having a plurality of cam rings. Among the plurality of cam rings, the fixed fixed cam ring is provided with a cam groove for moving a movable cam ring movable in the optical axis direction. The moving cam ring is held via a biasing member such as a spring that biases a plurality of spherical cam followers that fit into the cam groove of the fixed cam ring in a direction to engage with the cam groove. And the shape of the part which incorporates a some cam follower in a some cam groove is as follows. That is, among the plurality of cam followers, when the other cam follower is incorporated into the cam groove, the cam follower previously incorporated into the cam groove is fitted in the cam groove and the moving cam ring in the optical axis direction or the rotation direction so as to be already fitted and held. It consists of a step shape.

[Example 1]
FIG. 1 is an exploded perspective view of Embodiment 1 when the lens barrel of the present invention is applied to a zoom lens barrel of a photographing apparatus (optical apparatus) such as a digital camera or a video camera. FIG. 2 is a cross-sectional view of a main part of the zoom lens barrel of FIG. In these drawings, the zoom optical system in the lens barrel of the first embodiment of the present invention has a rear focus composed of first, second, and third groups having negative, positive, and positive refractive powers in order from the object side to the image side. 3 group zoom lens (zoom lens).

  In the zoom lens of this embodiment, zooming is performed by moving the first group (moving lens group) and the second group (moving lens group) in the optical axis direction. Then, focusing is performed by moving the third group (moving lens group) in the optical axis direction. Reference numeral 1 denotes a movable holding frame (first group lens barrel) that holds the first group (moving lens group). Three boss portions 1b and a follower moving hole portion 1a are provided on the outer peripheral side surface toward the center of the optical axis. Is provided. The hole 1a for moving the follower is not a through hole, but a bottomed hole that accommodates the spherical cam follower 30 and the coil spring 31. These three hole portions 1a are arranged at equal intervals on the outer peripheral portion of the movable holding frame 1. Reference numeral 2 denotes a moving holding frame (second group lens barrel) for holding the second group (moving lens group). Three boss portions 2b and a follower moving hole portion 2a are provided on the outer peripheral side surface toward the center of the optical axis. Is provided. The follower moving hole 2a is not a through hole but a bottomed hole that accommodates the spherical cam follower 32 and the coil spring 33. These three hole portions 2a are arranged at equal intervals on the outer peripheral portion of the movable holding frame 2.

  Reference numeral 3 denotes an aperture unit fixedly held on the movable holding frame 2, and has an aperture drive unit 3a and a shutter drive unit 3b separately. The diaphragm drive unit 3a drives a plurality of diaphragm blades to change the diaphragm aperture shape (diaphragm aperture diameter). The shutter driving unit 3b drives two swirl blades to perform a shutter operation from opening the aperture to fully closing. Reference numeral 4 denotes a movable holding frame (third group barrel) that holds the third group (moving lens group), and is guided by a guide shaft that is provided integrally with the guide bar 8 and the cover 9. The position of the movable holding frame 4 in the optical axis direction is regulated by a rack member 5 that is positioned in the optical axis direction on the arm portion 4a of the movable holding frame 4 and is rotatably attached. Reference numeral 7 denotes a stepping motor that rotationally drives the output screw 7a. The stepping motor 7 is fixed to the cover 9 with screws. The distal end of the output screw 7 a is rotatably held by a bearing portion formed integrally with the cover 9.

  The rack member 5 is pressed against the output screw 7 a of the stepping motor 7 by the force (biasing force) of the spring 6, and is driven in the optical axis direction by the rotation of the stepping motor 7. Reference numeral 10 denotes a CCD holder serving as a base part of the lens barrel unit, and forms a structure of the lens barrel unit together with a fixed lens barrel (fixed cam ring) 11 fixed to the front end portion thereof by screws. The cover 9 is fixed to the CCD holder 10 with screws. Reference numeral 12 denotes a photo interrupter fixed to the CCD holder 10, and a slit plate portion 4 b formed integrally with the movable holding frame 4 for the third group is disposed at a position where it can be retracted into the slit portion of the photo interrupter 12. ing. An image sensor (CCD) 24 and a low-pass filter are fixedly held in the CCD holder 10. Reference numeral 13 denotes a moving cam ring, and three bosses 13b and follower moving holes 13a are provided on the outer peripheral side surface toward the center of the optical axis.

  The hole 13a for moving the follower is not a through hole but a bottomed hole that accommodates a spherical cam follower 34 and a coil spring (biasing member) 35. These three holes 13a are arranged at equal intervals on the outer periphery of the movable cam ring 13. A cam groove 11 a is formed in the inner diameter portion of the fixed barrel 11, and a spherical cam follower 34 accommodated in the hole 13 a for moving the follower of the movable cam ring 13 is urged by the coil spring 35 in the cam groove 11 a. ing. Thereby, the movable cam ring 13 is extended in the optical axis direction by rotating the movable cam ring 13 along the cam groove 11a of the fixed barrel 11. The hole 13a for moving the follower is formed with a size that fits with the outer diameter of the spherical cam follower 34 without any play, and the coiled spring 35 supports the moving cam ring 13 at three points without play in the radial direction. This prevents tilting with respect to the optical axis and displacement in the optical axis direction.

  The fixed barrel 11 incorporates a zoom motor 14, a gear 17 attached to the output shaft thereof, a gear train 15 and an output gear 16 for reducing the output. By transmitting the rotational force of the zoom motor 14 to the gear teeth 13f formed on the outer periphery of the moving cam ring 13, the moving cam ring 13 is driven to rotate and controlled to move in the optical axis direction. The gear 17 is provided with three blades 17a for detecting the rotation of the zoom motor 14, and the photo interrupters 18 and 19 are arranged at an angle of 150 degrees so that the blade 17a blocks the slit portion. ing. A finder cam plate 20 has tapered cam grooves 20a and 20b for zoom driving the finder lens in the finder unit 21 on the surface. The finder cam plate 20 is rotatable along the outer peripheral portion of the fixed barrel 11, and the finder lens moves in conjunction with the movable cam ring 13 to zoom the finder optical system.

  A rectilinear guide tube 22 is rotatably fitted inside the movable cam ring 13, and a protrusion 22 a provided on the outer peripheral portion of the rectilinear guide tube 22 is provided on the inner peripheral surface of the fixed barrel 11. It is fitted in the groove 11b. As a result, the rectilinear guide tube 22 does not rotate with respect to the fixed barrel 11 and moves straight. Further, the two protrusions 22 b provided on the outer peripheral portion of the rectilinear guide tube 22 are fitted in a groove portion 13 c provided on the inner surface of the movable cam ring 13. For this reason, the rectilinear guide tube 22 and the movable cam ring 13 move together in the optical axis direction while being rotatable. The spherical cam follower 30 accommodated in the hole 1a for moving the follower of the group 1 moving holding frame 1 is urged and fitted into the cam groove 13d of the moving cam ring 13 by a coil spring (biasing means) 31. .

  The linear motion groove 22c provided on the outer peripheral surface of the linear guide tube 22 is engaged with the boss portion 1b provided on the movable holding frame 1 for the first group. The linear movement groove 22c restricts the movement and holding frame 1 for the first group from moving in the rotation direction. When the moving cam ring 13 is rotated, the movement and holding frame 1 for the first group is moved in the optical axis direction. Is paid out. Further, the hole 1a for moving the follower is formed with a size that fits with the outer diameter of the spherical cam follower 30 without play. Thus, the coil spring 31 supports three points of the movable holding frame for the first group without any play in the radial direction, and prevents tilting with respect to the optical axis and displacement in the optical axis direction. Similarly to the movement holding frame 1 for the first group, the movement holding frame 2 for the second group also has a spherical cam follower 32 housed in the hole 2a for moving the follower and is moved into the cam groove 13e of the moving cam ring 13 by the coil spring 33. Energized and fitted.

  The linear motion groove 22d provided on the outer peripheral surface of the linear guide tube 22 is fitted with a boss portion 2b provided on the second group moving holding frame 2. The linear movement groove 22d restricts the movement and holding frame 2 for the second group from moving in the rotation direction. When the movable cam ring 13 rotates, the movement and holding frame 2 for the second group is moved in the optical axis direction. Is paid out. Further, the follower moving hole 2a is formed to have a size that fits with the outer diameter of the spherical cam follower 32 without play. As a result, the movable holding frame 2 for the second group is supported at three points by the coil spring 33 without any play in the radial direction, and the tilt with respect to the optical axis and the displacement in the optical axis direction are prevented. The initial zoom position is detected by shielding a photo interrupter 23 fixed to the CCD holder 10 by a light shielding plate (not shown) provided on the straight guide tube 22. As described above, the gear 17 is provided with three blades 17 a for detecting the rotation of the zoom motor 14. The blade 17a blocks the slit portions of the photo interrupters 18 and 19, thereby converting the rotation of the zoom motor 14 into a pulse waveform and counting the pulse waveform. Thereby, the rotation speed of the zoom motor 14 is detected. This rotational speed is determined based on the zoom initial position described above as a reference.

FIG. 3 is a development view of the moving cam ring 13. In this figure, positions 1-A, 1-B, 1-C for incorporating the spherical cam followers 30 (30-1, 30-2, 30-3) into the movable holding frame 1 for the first group are the positions of the moving cam ring 13. They are arranged on the outer peripheral surface every 120 degrees. The end face (part) 101 into which the spherical cam follower 30 is incorporated is L1 ≧ d1 / 2 in the optical axis direction with respect to the diameter of the cam follower 30 = d1.
As shown in the figure, it has a step shape in the direction of the optical axis that is shifted in position. The order in which the spherical cam followers 3030-1, 30-2, and 30-3) are assembled into the group 1 movement holding frame 1 is positions 1-A, 1-B, and 1-C. After incorporating the cam follower (one cam follower) 301-1 at the position 1-A, the movable holding frame 1 for the first group is moved by the distance L1 in the optical axis direction, so that the spherical cam follower 30-1 at the position 1-A is a cam. It is fitted and held in the groove 13d.

  After incorporating the next cam follower (the other cam follower) 30-2 at the position 1-B, the movable holding frame 1 for the first group is further moved by the distance L1 in the optical axis direction, thereby moving the spherical cam follower 30- at the position 1-B. 2 is fitted and held in the cam groove 13d. Finally, after the next cam follower 30-3 is assembled at the position 1-C, the movable cam frame 1 for the first group is moved further by the distance L1 in the optical axis direction, so that the spherical cam follower 30-3 at the position 1-C The groove 13d is fitted and held. As described above, in the present embodiment, the movable cam ring 13 appropriately sets a portion in which the plurality of cam followers 30-1, 30-2, 30-3 are incorporated into the plurality of cam grooves 13d. That is, when the other cam follower 30-2 is assembled into the cam groove 13d, the optical follower 30-1 previously assembled into the cam groove 13d is fitted and held by the cam groove 13d and the movable holding frame 1 in advance. It consists of a step shape in the direction.

Similarly, positions 2-A, 2-B, and 2-C, in which spherical cam followers 32 (32-1, 32-2, and 32-3) are incorporated into the movable holding frame 2 for the second group, are arranged every 120 degrees. ing. The end face into which the spherical cam follower 32 is incorporated is L1 ≧ d1 / 2 in the optical axis direction with respect to the diameter of the cam follower 32 = d1.
The positions are shifted so that The order in which the spherical cam followers 32 (32-1, 32-2, 32-3) are incorporated into the second group movement holding frame 2 is the same as that of the first group movement holding frame 1 in positions 2-A, 2-B, 2-C. That is, after incorporating the cam follower 32-1 at the position 2-A, the movable holding frame 2 for the second group is moved by the distance L1 in the optical axis direction, so that the spherical cam follower 32-1 at the position 2-A is inserted into the cam groove 13e. Fit and hold.

  After the next cam follower 32-2 is assembled at the position 2-B, the sphere cam follower 32-2 at the position 2-B is moved into the cam groove 13e by moving the movable holding frame 2 for the second group further in the optical axis direction by the distance L1. Fitted and held. Finally, after the next cam follower 32-3 is assembled at position 2-C, the sphere cam follower 32-3 at position 2-C is camped by moving the second group moving holding frame 2 further in the optical axis direction by a distance L1. It will be fitted and held in the groove 13e. The positions of the movable cam ring 13 at positions 1-C and 2-C are concave in the optical axis direction with respect to other shapes. Therefore, by disposing the focus motor or the like at this position when the lens barrel is retracted, the retracted length is shortened. can do.

FIG. 4 shows a cam development view of the fixed barrel (fixed cam ring) 11. In this figure, positions 3-A, 3-B, and 3-C for incorporating a spherical cam follower 34 into the cam groove 11a of the movable cam ring 13 are arranged at intervals of 120 degrees. It consists of a step shape in the optical axis direction. The insertion hole 11c into which the spherical cam follower 34 is incorporated is L2 ≧ (D1 + D2) / 2 in the optical axis direction with respect to the diameter of the cam follower 34 = D1 and the insertion hole diameter = D2.
The positions are shifted so that

  The order in which the spherical cam followers 34 (34-1, 34-2, 34-3) are incorporated into the movable cam ring 13 is positions 3-A, 3-B, and 3-C. That is, after incorporating the cam follower 34-1 at the position 3-A, the spherical cam follower 34-1 at the position 3-A is fitted and held in the cam groove 11a by moving the movable cam ring 13 by the distance L2 in the optical axis direction. The After incorporating the next cam follower 34-2 at position 3-B, the movable cam ring 13 is moved further in the optical axis direction by a distance L2, so that the spherical cam follower 34-2 at position 3-B is fitted and held in the cam groove 11a. Is done. Finally, after the next cam follower 34-3 is assembled at the position 3-C, the movable cam ring 13 is moved further in the optical axis direction by a distance L2, so that the spherical cam follower 34-3 at the position 3-C is fitted into the cam groove 11a. Will be held together. As described above, in the present embodiment, the fixed barrel (fixed cam ring) 11 appropriately sets a portion in which the plurality of cam followers 34-1, 34-2 and 34-3 are incorporated into the plurality of cam grooves 11a. That is, when assembling the other cam follower 34-2 into the cam groove 11a, the optical follower 34-1 is previously fitted and held by the cam groove 11a and the movable cam ring 13 so that the cam follower 34-1 previously incorporated in the cam groove 11a is fitted and held. It consists of a step shape in the direction.

  FIG. 5 is a schematic view of the main part of another embodiment of the first embodiment. FIG. 5 shows a form in which the movable holding frame 101 itself has a spring property and the spherical cam follower 30 is urged to the cam groove 13 d of the movable cam ring 13. Three boss portions 101b and conical follower moving recesses (holes) 101a are provided on the outer peripheral side surface of the movable holding frame 101 toward the center of the optical axis. These three hole portions 101 a are arranged at equal intervals on the outer peripheral portion of the movable holding frame 101. The spherical cam follower 30 housed in the conical follower moving recess 101 a provided on the moving holding frame 101 is urged and fitted into the cam groove 113 d of the moving cam ring 13 by a spring portion 101 c formed integrally with the moving holding frame 101. Yes. The linear motion groove 22 c of the rectilinear guide tube 22 is fitted with a boss portion 101 b provided on the movement holding frame 101. The linear movement groove 22c restricts the movement of the movable barrel 101 in the rotational direction. When the movable cam ring 13 rotates, the movable holding frame 101 is extended in the optical axis direction. Further, the conical follower moving recess 101a is formed in a conical shape that fits with the outer diameter of the spherical cam follower 30 without any play, and the spring holding part 101c supports the moving holding frame 101 at three points without any play in the radial direction. In addition, tilting with respect to the optical axis and positional deviation in the optical axis direction are prevented. The spring portion 101 c and the conical follower moving recess 101 a that are integrally formed with the moving holding frame 101 may be configured separately from the moving holding frame 101.

[Example 2]
FIG. 6 is an explanatory view of a part of the lens barrel of the second embodiment of the present invention. FIG. 6 shows an exploded view of the cam portion of the fixed barrel (fixed cam groove) 211. In this figure, the positions 3-D, 3-E, and 3-F for incorporating the spherical cam follower 34 into the cam groove 211a of the movable cam ring 13 are arranged at positions shifted by S1 from 120 degrees. The insertion hole 11c into which the spherical cam follower 34 is incorporated is L3 ≧ (D1 + D2) / 2 around the optical axis with respect to the cam follower 34 diameter = D1 and the insertion hole diameter = D2.
The positions are shifted so that

  The order in which the spherical cam followers 34 (34-1, 34-2, 34-3) are incorporated into the movable cam ring 13 is positions 3-D, 3-E, and 3-F. That is, after the cam follower 34-1 is assembled at the position 3-D, the movable cam ring 13 is moved along the cam groove 211a by the distance L3 around the optical axis, so that the spherical cam follower 34-1 at the position 3-D becomes the cam groove. 211a is fitted and held. After the next cam follower 34-2 is assembled at position 3-E, the movable cam ring 13 is moved around the optical axis by a distance L3, so that the spherical cam follower 34-2 at position 3-E is fitted and held in the cam groove 211a. Is done. Finally, after the next cam follower 34-3 is assembled at the position 3-F, the movable cam ring 13 is moved around the optical axis by a distance L3 so that the spherical cam follower 34-3 at the position 3-F is fitted into the cam groove 211. Will be held together.

  As described above, in the lens barrel of the present invention, in a collapsible lens barrel that is zoomed or focused by moving in the optical axis direction with a plurality of cam grooves and a plurality of spherical cam followers, the spherical cam followers are inserted into the cam grooves. The position to be shifted is arranged at a position shifted in the optical axis direction. In addition, it may be arranged at a position shifted in the optical axis direction and the rotation direction. Accordingly, when the cam followers of the individual spheres are assembled, the cam followers of the other spheres are fitted and positioned in the cam grooves to facilitate assembling. In the present embodiment, the cam groove of the fixed barrel 211 at the position where the spherical cam follower 34 is incorporated has a lift, but may be a flat cam groove that does not move in the optical axis direction. In this embodiment, the relationship between the movable cam ring and the fixed barrel having the fixed cam is shown. However, as in the first embodiment, the relationship between the movable cam ring and the movable barrel may be used.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist. For example, the following configuration can be applied as another form of the lens barrel of each embodiment. A fixed cam ring included in a lens mirror or the like is provided with a plurality of cam grooves for moving a moving holding frame for holding a moving lens group. The movable holding frame holds a plurality of spherical cam followers that respectively fit into the plurality of cam grooves of the fixed cam ring via a biasing member that biases the cam follower in a direction to engage with the cam groove. The portion of the fixed cam ring that incorporates the plurality of cam followers into the plurality of cam grooves is as follows when the other cam follower is incorporated into the cam groove. That is, the cam follower previously incorporated in the cam groove may be configured to have a step shape in the optical axis direction so as to be already fitted and held by the cam groove and the movable holding frame.

1 is a moving holding frame that holds the moving lens group of the first group, 2 is a moving holding frame that holds the moving lens group of the second group, 3 is a diaphragm unit, and 4 is a movement that holds the moving lens group of the third group. Holding frame, 10 is a CCD holder, 11 is a fixed lens barrel having a fixed cam, 13 is a moving cam ring, 22 is a rectilinear guide tube, 30, 32 and 34 are spherical cam followers, and 31, 33 and 35 are coil springs (attached) Means)

Claims (4)

In a lens barrel having one or more cam rings that shift in the optical axis direction, one of the one or more cam rings has a moving holding frame that holds a moving lens group inside thereof. And a plurality of spherical cam followers that respectively fit in the plurality of cam grooves of the cam ring are urged in the moving holding frame in a direction to engage with the cam grooves. The cam ring has a portion where the plurality of cam followers are incorporated into the plurality of cam grooves, and when the other cam follower is incorporated into the cam groove, the cam follower previously incorporated into the cam groove is the cam ring. A lens barrel having a step shape in the optical axis direction so as to be already fitted and held by the groove and the movable holding frame.   In a lens barrel having a plurality of cam rings, among the plurality of cam rings, the fixed fixed cam ring is provided with a cam groove for moving a movable cam ring movable in the optical axis direction on the inner side. The movable cam ring is held via a biasing member that biases a plurality of spherical cam followers that fit into the cam grooves of the fixed cam ring in a direction to engage with the cam grooves. When the ring incorporates the plurality of cam followers into the plurality of cam grooves, when the other cam follower is incorporated into the cam groove, the cam follower previously incorporated in the cam groove is already fitted by the cam groove and the movable cam ring. A lens barrel having a step shape in the optical axis direction so as to be held.   In the lens barrel having a fixed cam ring, the fixed cam ring is provided with a plurality of cam grooves for moving a moving holding frame for holding the moving lens group on the inner side thereof. A plurality of spherical cam followers that respectively fit into the plurality of cam grooves of the fixed cam ring are held via biasing members that bias in a direction to engage with the cam groove, and the fixed cam ring is When the portion that incorporates the plurality of cam followers into the plurality of cam grooves is incorporated into the cam groove, the cam follower that was previously incorporated into the cam groove is already fitted and held by the cam groove and the movement holding frame. Thus, a lens barrel having a step shape in the optical axis direction.   An optical apparatus comprising the lens barrel according to claim 1, 2 or 3.