JP2004258650A - Light shielding structure for collapsible lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light shielding structure for a collapsible lens barrel capable of realizing miniaturization and thinning. <P>SOLUTION: The light shielding structure for the collapsible lens barrel equipped with a lens system whose position is changed between a photographing position and a housing position, is provided with a lens fixing frame which fixes a lens group that adjusts the position of the optical axis direction at the time of assembly; a moving barrel member on which the lens fixing frame is screwed and which is moved to draw a specified locus; a light shielding member supported movably in a front-and-rear direction by regulating its retreat end on the moving barrel member and preventing harmful light from entering; and a 1st spring member provided to be contracted between the light shielding member and the lens fixing frame and energizing and moving the light shielding member to a backward projecting end. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a light-shielding structure for a retractable lens barrel.

  As a light-shielding structure of a retractable lens barrel, a structure is known in which a light-shielding member for preventing harmful light from entering is supported on a lens frame supporting a lens group.

  However, in the case of the collapsible lens barrel, the distance between the lens groups changes greatly, and accordingly, the light blocking member needs to be arranged at a position relatively far from the lens frame. In particular, in the case of a lens barrel using a high-magnification zoom lens as the optical system, the tendency becomes stronger, and an adjustment mechanism for the lens group is also required. Therefore, it is more difficult to make the lens barrel thinner and smaller.

  An object of the present invention is to provide a light-shielding structure of a collapsible lens barrel that can be reduced in size and thickness.

  The light-shielding structure of the collapsible lens barrel of the present invention is a collapsible lens barrel provided with a lens system whose position changes between a shooting position and a storage position, and includes a lens group that adjusts an optical axis direction position during assembly. A fixed lens fixing frame; a moving cylinder member which is screwed to the lens fixing frame and is moved along a predetermined trajectory; harmful light supported by the moving cylinder member so as to be movable in the front-rear direction with its retreating end regulated. A first spring member, which is provided between the light-shielding member and the lens fixing frame, for urging the light-shielding member toward a rearwardly projecting end; I have.

  The moving cylinder member is formed by screwing the moving cylinder that is moved forward and backward in the optical axis direction by a cam mechanism in accordance with a zooming operation, and the lens fixing frame that is supported by the moving cylinder so as to be movable in the optical axis direction by regulating the forward end. It is practical to have a second spring member which is composed of a combined intermediate cylinder member and constantly biases the intermediate cylinder member forward.

  Further, at least the lens group fixed to the lens fixing frame can be a variable power lens group.

  ADVANTAGE OF THE INVENTION According to this invention, in a collapsible lens barrel, not only the degree of freedom of installation of a light-shielding member in a shooting state is improved, but also miniaturization and thickness reduction become possible.

  First, a zoom lens optical system according to an embodiment in which the present invention is applied to a zoom lens barrel will be described with reference to FIG. The zoom lens system includes, in order from the object side, a first lens unit L1 having a positive power, a second lens unit L2 having a negative power, a third lens unit L3 having a positive power, and a fourth lens unit having a positive power. This is a varifocal lens system composed of L4. The zooming is performed by the first to third lens units L1 to L3, and the focus movement accompanying the zooming is corrected by the fourth lens unit L4. During zooming, the first lens unit L1 and the third lens unit L3 move together at a constant interval. The fourth lens unit L4 is a focus group at the same time. FIG. 1 illustrates both the zooming locus and the locus during storage. Strictly speaking, the varifocal lens system is defined as a lens system in which the focal point moves with zooming, and the zoom lens system is defined as a lens system in which the focal point does not move. The varifocal lens system is referred to as a zoom lens system in the following description.

  1 to 19, the entire structure of the zoom lens barrel according to the present embodiment will be described. As shown in, for example, FIG. 8, the fixed cylinder 11 fixed to the camera body has a female helicoid 11a on its inner peripheral surface and a straight guide groove 11b in a direction parallel to the optical axis. As shown in FIG. 9, a male helicoid 12a formed at the rear end of the cam helicoid ring 12 is screwed into the female helicoid 11a of the fixed cylinder 11. A spur gear 12b is formed at the peak of the male helicoid 12a, and the spur gear 12b is positioned in an inner surface recess 11c (FIG. 3) of the fixed cylinder 11 and is rotatably supported by a drive pinion 13 (FIG. 15). (See)). Therefore, when the cam helicoid ring 12 rotates via the drive pinion 13 and the spur gear 12b, it moves in the optical axis direction according to the male helicoid 12a and the female helicoid 11a. In the zoom lens barrel of the present embodiment, the cam helicoid ring 12 is the only rotating member about the optical axis.

  A rectilinear guide ring 14 is fitted on the outer periphery of the cam helicoid ring 12. The rectilinear guide ring 14 has a radial rectilinear guide protrusion 14a on the outer surface of its rear end, and a bayonet protrusion 14b (FIG. 4) on the inner surface of the rear end. The rectilinear guide projection 14a is relatively movably fitted in the rectilinear guide groove 11b of the fixed cylinder 11, and the bayonet protrusion 14b is a circumferential groove formed immediately before the male helicoid 12a (spur gear 12b) of the cam helicoid ring 12. 12c is relatively rotatably fitted. Therefore, the rectilinear guide ring 14 moves together with the cam helicoid ring 12 in the optical axis direction without rotating.

  On the outer peripheral surface of the cam helicoid ring 12, as shown in FIGS. 4, 9, and 16, a cam groove C15 for the first group moving barrel 15 supporting the first lens group L1, and a cam groove for the decorative barrel 16 are provided. C16 is formed, and a cam groove C17 (see FIG. 19) for the second group moving cylinder 17 supporting the second lens group L2 is formed on the inner peripheral surface. The first group cam groove C15 and the decorative cylinder cam groove C16 have slightly different shapes and are each formed three in the circumferential direction so as to be spaced apart from each other. The second group cam groove C17 has the same basic trajectory in the circumferential direction and the optical axis. Six are formed apart from each other in the direction. The first group moving cylinder 15, the decoration cylinder 16, and the second group moving cylinder 17 are respectively guided in a straight line in the optical axis direction, and follow the first group cam groove C15, the decoration cylinder cam groove C16, and the second group cam groove C17. The cam helicoid ring 12 advances and retreats in the optical axis direction with rotation.

  The following describes the straight-ahead guidance relationship. As shown in FIGS. 4 and 5, the first-group moving cylinder 15 has a U-shaped cross section including an outer cylinder 15X, an inner cylinder 15Y, and a flange wall 15Z connecting the outer cylinder 15X and the distal end of the inner cylinder 15Y. The cam helicoid ring 12 is located between the outer cylinder 15X and the inner cylinder 15Y. A cam follower 15a that fits into the first group cam groove C15 of the cam helicoid ring 12 is fixed to the rear end of the outer cylinder 15X. As shown in FIGS. 8 and 9, a first group frame 24 to which the first lens unit L1 is fixed is screwed and fixed to the distal end of the inner cylinder 15Y. The first group frame 24 can be used when performing zooming adjustment by adjusting the position of the first lens unit L1 in the optical axis direction.

  Straight guide grooves 14c (FIG. 9) parallel to the optical axis are formed on the inner peripheral surface of the straight guide ring 14 guided straight to the fixed cylinder 11 at approximately 120 ° intervals. A linear guide projection 15b radially projecting from the rear end of the outer cylinder 15X is fitted. A narrow straight guide groove 15d (FIG. 16) is formed at the rear end of the assembling groove 15c in the outer cylinder 15X of the first group movable barrel 15, and the straight guide groove 15d is formed to move straight with the outer cylinder 15X. A straight guide key 16a fixed to the decoration tube 16 located between the guide rings 14 is located. The relative movement distance in the optical axis direction between the first group moving cylinder 15 and the decoration cylinder 16 (the difference in the shape of the first group cam groove C15 and the decoration cylinder cam groove C16) is small, and the optical axis direction of the straight guide groove 15d. Is correspondingly short. The straight guide key 16a is integrally provided with a cam follower 16b fitted into the decorative cylinder cam groove C16.

  A compression coil spring 19 (see FIGS. 3 to 5) is inserted between the first-group moving cylinder 15 and the decoration cylinder 16. The compression coil spring 19 urges the first group moving cylinder 15 rearward and the decoration cylinder 16 forward to move the first group moving cylinder 15 between the first group cam groove C15 and the cam follower 15a, and between the first group cam groove C15 and the cam follower 16b. It acts to take backlash between.

  Also, as shown in FIG. 16, the first group cam groove C15 and the decorative cylinder cam groove C16 project the decorative cylinder 16 forward with respect to the first group moving cylinder 15 at the storage position compared to the photographing position. The shape is set slightly different so as to prevent interference between the barrier of the barrier block 30 (FIG. 8) and the first lens unit L1. More specifically, as shown in FIG. 16, the optical axis direction distance Q between the first group cam groove C15 and the decorative cylinder cam groove C16 is greater in the preparation section (the section from the storage position to the full opening of the barrier). The shapes of the first group cam groove C15 and the decorative cylinder cam groove C16 are set so as to be larger than the zoom section (the section from the wide end position to the tele end position). That is, in the preparation section, Q = Q1 in all sections, but the distance Q gradually decreases from the position OP2 that has passed the barrier full-open position OP1 by a predetermined amount (that is, from the position where the lens L1 does not interfere with the barrier). , Q = Q2 (<Q1) at the wide end position. Then, in the zoom section, Q = Q2 in all the sections. In the storage position shown in FIG. 3, the clearance c1 between the flange wall 15Z at the front end of the first-group moving barrel 15 and the flange wall of the decorative barrel 16 located in front of it is in the photographing state shown in FIG. 4 or FIG. It can be seen that the gap is formed larger than the clearance between the two flange walls in FIG. In other words, at the photographing position, the barrier block 30 is moved closer to the first lens unit L1 to prevent vignetting by the barrier block 30. The barrier block 30 is supported by the front end of the decoration tube 16. By rotating the barrier opening / closing ring 31 (FIG. 9) located immediately behind the barrier block 30 by the cam helicoid ring 12 near the storage position. , Open and close the barrier. A barrier mechanism that opens and closes the barrier block 30 by the rotation of the barrier opening / closing ring 31 is well known. In the present embodiment, the shapes of the first group cam groove C15 and the decorative cylinder cam groove C16 are set so that the distance Q becomes a constant value (= Q2) in the zoom section. Alternatively, the distance Q may be changed so that the distance Q in the zoom section is larger than the distance Q in the preparation section.

  The decorative tube cam groove C16 has an open front end, and the cam follower 16b of the decorative tube 16 is inserted into the cam groove C16 from its open end C16a (FIG. 16) at a specific assembly position. You. Similarly, the cam follower 15a of the first-group moving cylinder 15 is inserted into the first-group cam groove C15 from the front-end open end C15a.

  The inner cylinder 15Y of the first group moving cylinder 15 is formed with a straight guide protrusion 15f (FIGS. 6 and 7) in a direction parallel to the optical axis on its inner peripheral surface. A rectilinear guide groove 17a is formed in a direction parallel to the optical axis in which the rectilinear guide protrusion 15f is slidably fitted. A suspension groove 15e in a direction parallel to the optical axis is formed at the center of the straight guide projection 15f, and the rear end of the suspension groove 15e is closed (see FIGS. 17 and 18). The second group moving cylinder 17 is formed with a cam follower 17c that fits into the second group cam groove C17 of the cam helicoid ring 12.

  On the inner circumference of the second group moving barrel 17, a third group moving barrel 18 supporting the third lens unit L3 is located. The third-group moving barrel 18 has a straight-moving guide projection 18a that is parallel to the optical axis and is fitted into the straight-moving guide groove 17a of the second-group moving barrel 17 so as to be relatively slidable from the inside. A linear key 18b (FIGS. 11, 17, and 18) that fits into the suspension groove 15e is formed at the center of the linear guide protrusion 18a. As shown in FIG. 11, a shutter block 20 is inserted into the third group moving barrel 18 in front of the third lens unit L3, and is fixed by a holding ring 20a. A compression coil spring 21 is inserted between the third group moving cylinder 18 (holding ring 20 a) and the second group moving cylinder 17. To move backward. The rearward moving end of the third group moving barrel 18 is regulated at a position where the straight key 18b contacts the rear end of the hanging groove 15e of the first group moving barrel 15. That is, in the photographing state, the state in which the straight key 18b is in contact with the rear end of the suspension groove 15e of the first group moving barrel 15 is maintained, and the relative distance between the first lens group L1 and the third lens group L3 is constant. It becomes. When the zoom lens barrel changes from the photographing state to the housed state, after the third lens group L3 (the third group moving cylinder 18) reaches the mechanical retreat end, the first lens group L1 is moved to the first group cam. When the compression coil spring 21 is further retracted according to the groove C15, the first lens unit L1 approaches the third lens unit L3 (see FIG. 1). The head of the rectilinear key 18b is swollen to prevent the straight key 18b from falling out of the suspension groove 15e.

  The compression coil spring 21 may act directly on the second-group moving barrel 17 (the second lens group L2 may be fixed to the second-group moving barrel 17), but in the illustrated embodiment, the storage length is further reduced. In order to achieve the above, the second lens unit L2 can be moved backward with respect to the second unit moving barrel 17. FIGS. 12 and 13 show the configuration. The second-group moving barrel 17 is formed with a tubular part 17e having an inner flange 17d at the distal end. The tubular part 17e has an optical axis and Three straight guide grooves 17f which are parallel and open at the rear and front ends are formed at equal angular intervals in the circumferential direction. A flange portion 25a formed on the intermediate tubular member 25 is fitted in the cylindrical portion 17e, and three radially outward guide projections 25d projecting from the outer peripheral surface of the flange portion 25a at equal angular intervals in the circumferential direction. Are respectively fitted in the corresponding straight guide grooves 17f from behind. For this reason, the relative rotation of the intermediate cylinder member 25 around the optical axis with respect to the second group movable cylinder 17 is restricted, and the intermediate cylinder member 25 can move only in the optical axis direction, and the front surface of the flange portion 25a is the rear surface of the inner flange 17d. Can move forward until it abuts. The second lens group L2 is fixed to the second group frame 26, and the male screw 26b of the second group frame 26 is screwed into the female screw 25e formed on the inner periphery of the intermediate cylindrical member 25. Therefore, by rotating the second lens group frame 26 with respect to the intermediate cylinder member 25 whose rotation about the optical axis is restricted, the position of the second lens unit L2 in the optical axis direction can be adjusted (zooming adjustment). After the adjustment, the second group frame 26 can be fixed to the intermediate cylindrical member 25 by dropping the adhesive from the adhesive hole 25b. A gap c2 (FIG. 13) including an adjustment margin exists between the front end face of the inner flange 17d of the second group moving cylinder 17 and the outer flange 26a of the second group frame 26. The compression coil spring 21 acts on the intermediate cylinder member 25, and the intermediate cylinder member 25 is normally held at a position where the flange portion 25a is in contact with the inner flange 17d (in a photographing state). That is, the position of the second lens group L2 is controlled by the second group cam groove C17 in the photographing state, while the second group frame 26 is mechanically pushed rearward by the rear end of the first group frame 24 during storage. The outer flange 26a can be retracted to a position where it contacts the inner flange 17d, and the storage length can be reduced by the gap c2.

  The light shielding frame 27 is supported by the intermediate cylindrical member 25. The light-shielding frame 27 includes an annular light-shielding portion 27a, a holding leg 27b extending forward from the annular light-shielding portion 27a at an interval of approximately 120 °, and a retaining hook portion 27c obtained by bending the tip of the holding leg 27b outward. The light blocking member holding hole 25c into which the retaining hook portion 27c fits is formed in the intermediate cylindrical member 25 (FIG. 12). A conical coil spring 28 is inserted between the light-shielding frame 27 and the second group frame 26 to constantly move and bias the light-shielding frame 27 backward. When the light-blocking frame 27 reaches the mechanically retracted end when the lens barrel is stored, the light-blocking frame 27 approaches the second group frame 26 by bending the conical coil spring 28. The length of the light shielding member holding hole 25c in the optical axis direction is set so that the annular light shielding portion 27a can abut on the second lens group L2.

  The conical coil spring 28 also functions to remove backlash during zooming adjustment performed by rotating the second group frame 26. The zooming adjustment is an adjustment performed by adjusting the position of the second lens unit L2 in the optical axis direction while observing the image position. The backlash of the second group frame 26 with respect to the intermediate cylinder member 25 (the second group moving cylinder 17) is reduced. By removing, accurate adjustment can be made.

  The fourth lens unit L4 is fixed to the fourth unit frame 22. As described above, the fourth lens unit L4 has a role of correcting the focal point movement of the varifocal lens system and a role of a focus lens unit, and is controlled by the pulse motor 23 to move forward and backward. That is, the drive shaft of the pulse motor 23 is the screw shaft 23a, and the nut member 23b whose rotation is restricted is screwed to the screw shaft 23a. The nut member 23b is constantly urged by the spring means S to move in the direction in which it comes into contact with the foot 22a of the fourth group frame 22, and the rotation of the fourth group frame 22 is restricted by the guide bar 22b. Therefore, when the pulse motor 23 is driven, the fourth group frame 22 (the fourth lens group L4) moves forward and backward in the optical axis direction. The pulse motor 23 is controlled according to the focal length information and the subject distance information.

  Therefore, when the cam helicoid ring 12 is rotated via the drive pinion 13 in the present zoom lens barrel having the above-described structure, the first group moving cylinder 15, the decoration cylinder 16, and the second group moving cylinder 17 that are guided in a straight line form the cam groove. It moves in the optical axis direction according to C15, C16, and C17. The third group moving barrel 18 moves together with the first group moving frame 15 when the first group moving barrel 15 moves forward from the storage position and the rectilinear key 18b abuts on the rear end of the hanging groove 15e. The position of the fourth lens unit L4 is controlled by the pulse motor 23 controlled according to the focal length information, and the focal movement of the varifocal lens system is corrected. As a result, a zooming locus as shown in FIG. 1 is obtained. The pulse motor 23 is also controlled by subject distance information, and executes a focusing operation.

  As described above, in the present embodiment, the second group moving cylinder (moving cylinder member) (moving cylinder) located inside the cam helicoid ring 12 is provided in the cam groove C17 formed on the inner peripheral surface of the cam helicoid ring 12 that is driven to rotate. The cam follower 17c of 17) is fitted, and the second group moving cylinder 17 is guided straight by the first group moving cylinder 15. Inside the second group moving cylinder 17, an intermediate cylindrical member (moving cylindrical member) 25 whose forward end with respect to the second group moving cylinder 17 is regulated by the flange portion 25a abutting on the inner flange 17d is arranged in the optical axis direction. The male screw 26b of the second group frame (lens fixing frame) 26 to which the second lens group L2 is fixed is screwed with the female screw 25e of the intermediate cylinder member 25. The cam groove C17 of the cam helicoid ring 12 and the cam follower 17c of the second group moving cylinder 17 are constituent elements of a cam mechanism for moving the second group moving cylinder 17 in the optical axis direction.

Behind the second-group moving barrel 17, a third-group moving barrel 18 that supports the third lens group L3 is located. The third-group moving barrel 18 includes the inner cylinder 15Y of the first-group moving barrel 15 and the second-group moving barrel 17 And it is guided straight. Further, between the intermediate cylinder member 25 and the third-group movable cylinder 18, the intermediate cylinder member 25 is always moved to the forward end with respect to the second-group movable cylinder 17, and the second-group movable cylinder 17 and the third-group movable cylinder 18 are moved. A compression coil spring (a second spring member) 21 for urging the moving direction in a direction of separating from each other is contracted.
Then, when the cam helicoid ring 12 is rotated around the optical axis, the second group moving cylinder 17 and the third group moving cylinder 18 move in the front-rear direction, and the second lens group L2 and the third lens group L3 operate as zoom lenses. I do.

  A light-shielding frame (light-shielding member) 27 having an annular light-shielding portion 27a and holding legs 27b extending forward from the annular light-shielding portion 27a at intervals of approximately 120 ° is disposed behind the intermediate cylindrical member 25. The hook portion 27c of the holding leg 27b is supported by the light shielding member holding hole 25c of the intermediate cylindrical member 25. Further, a conical coil spring (first spring member) 28 is contracted between the second group frame 26 and the annular light shielding portion 27a, and constantly biases the light shielding frame 27 backward.

When the zoom lens barrel is in the photographing state, as shown in FIG. 13, the annular light shielding portion 27a is moved rearward relative to the second group moving cylinder 17 by the conical coil spring 28, 27a prevents harmful light from entering. The position of the annular light-shielding portion 27a can be arbitrarily set by changing the length of each holding leg 27b in accordance with the characteristics of the zoom optical system, etc., so that the position of the intermediate light-shielding frame 27 is supported. The light shielding frame 27 can be installed without being restricted, and the degree of freedom in design is improved.
On the other hand, when the zoom lens barrel shifts to the retracted state, as shown in FIG. 3, the annular light-shielding portion 27a comes into contact with the third-group moving barrel 18 and resists the urging force of the conical coil spring 28, so that the annular light-shielding portion 27a Moves in the opposite direction to the intermediate cylinder member 25 and approaches the second group movable cylinder 17. At this time, the hook portion 27c of each holding leg 27b advances toward the inner flange 17d through the inside of the cylindrical portion 17e of the second group moving barrel 17, and the length of each holding leg 27b in the optical axis direction is Is absorbed by the dimension of the cylindrical portion 17e in the optical axis direction.
Since the gap between the second group frame 26 and the annular light-shielding portion 27a that is present in the shooting state is eliminated during storage, the zoom lens barrel can be made thinner during storage.

  Further, as described above, the light-shielding frame 27 is linked with the conical coil spring 28, and the male screw 26b of the second group frame 26 and the female screw 25e of the intermediate cylinder member 25 during zooming adjustment performed by rotating the second group frame 26. It acts as a backlash eliminator. Since the zooming adjustment adjusts the position of the second lens unit L2 in the optical axis direction while observing the image position, accurate zooming adjustment becomes possible by performing such backlash removal. That is, the light blocking structure of the lens barrel can be used for backlash removal of the lens group for adjusting the position in the optical axis direction during assembly.

The zoom lens barrel described with reference to FIGS. 1 to 19 is an example to which the light-shielding structure of the present invention is applied, regardless of whether the cam ring is a helicoid cam ring or not. Obviously, the present invention can be applied to a lens barrel in general.
Further, the present invention can of course be applied to a collapsible lens barrel having no zoom function.

FIG. 3 is a diagram illustrating a basic zooming locus of a zoom lens system to which the zoom lens barrel according to the present invention is applied. FIG. 2 is a half-cut perspective view showing constituent lens groups and the lens frame of the zoom lens system. FIG. 2 is an upper half cross-sectional view of the zoom lens barrel in a housed state according to an embodiment of the present invention. FIG. 3 is an upper half cross-sectional view of the zoom lens barrel in a wide-angle infinity shooting state. FIG. 3 is a lower half cross-sectional view of the zoom lens barrel in a telephoto infinity shooting state. FIG. 6 is a sectional view taken along the line VI-VI of FIG. 3. FIG. 7 is a sectional view taken along line VII-VII in FIG. 3. FIG. 3 is an exploded perspective view of a part of the zoom lens barrel. It is an exploded perspective view of another part. FIG. 4 is an exploded perspective view around the first group moving cylinder. FIG. 10 is an exploded perspective view around the third group moving cylinder. It is an exploded perspective view around the 2nd group moving cylinder. It is an upper half sectional view around a 2nd group moving cylinder. It is the disassembled perspective view seen from the back surface around the pulse motor supported by the fixed cylinder. FIG. 4 is an exploded perspective view around the fixed cylinder and a fourth lens group. It is a development view of the cam groove for the 1st group of the cam helicoid cylinder, and the cam groove for the decoration cylinder. It is a development view which shows the linear guidance relationship of a 1st group moving cylinder, a 2nd group moving cylinder, and a 3rd group moving cylinder. FIG. It is a development view showing the shape of the cam groove for the 2nd group of the cam helicoid ring.

Explanation of reference numerals

C15 Group 1 cam groove C16 Decorative tube cam groove C17 Group 2 cam groove (cam mechanism)
L1 First lens unit L2 Second lens unit L3 Third lens unit L4 Fourth lens unit S Spring means 11 Fixed cylinder 11a Female helicoid 11b Straight guide groove 11c Inner recess 12 Cam helicoid ring 12a Male helicoid 12b Spur gear 12c Circumferential groove 12d Straight guide groove 13 Drive pinion 14 Straight guide ring 14a Straight guide projection 14b Bayonet projection 14c Straight guide groove 15 First group moving cylinder 15a Cam follower 15b Straight guide projection 15c Assembly groove 15d Straight guide groove 15e Suspension groove 15f Straight guide projection 15X Tube 15Y Inner tube 15Z Flange wall 16 Decorative tube 16a Straight guide key 16b Cam follower 17 Second group moving tube (moving tube member) (moving tube)
17a Straight guide groove 17c Cam follower (cam mechanism)
17d inner flange 17e cylindrical portion 17f rectilinear guide groove 18 third group moving cylinder 18a rectilinear guide protrusion 18b rectilinear key 19 compression coil spring 20 shutter block 20a retaining ring 21 compression coil spring (second spring member)
22 4th group frame 22a Foot 22b Guide bar 23 Pulse motor 23a Screw shaft 23b Nut member 24 First group frame 25 Intermediate cylindrical member 25a Flange 25b Adhesive hole 25c Light shielding member holding hole 25d Guide projection 25e Female screw 26 2nd group frame (lens Fixed frame)
26a Outer flange 26b Male screw 27 Light shielding frame (light shielding member)
27a Annular light shielding portion 27b Holding leg 27c Retaining hook portion 28 Conical coil spring (first spring member)
30 barrier block 31 barrier ring

Claims (3)

A collapsible lens barrel having a lens system whose position changes between a shooting position and a storage position, wherein a lens fixing frame in which a lens group for adjusting a position in an optical axis direction during assembly is fixed;
A moving cylinder member which is screwed with the lens fixing frame and is moved along a predetermined trajectory;
A light-blocking member for preventing the entry of harmful light, which is supported by the movable cylinder member so as to be movable in the front-rear direction by regulating a retreat end; and is shrunk between the light-shielding member and the lens fixing frame. A first spring member for moving and biasing the light shielding member toward the rearward projecting end;
A light-blocking structure for a collapsible lens barrel, comprising: 2. The collapsible lens barrel light-shielding structure according to claim 1, wherein the movable cylinder member is moved in the optical axis direction by a cam mechanism in accordance with a zooming operation, and the movable cylinder is controlled to have a forward end. A retractable lens mirror comprising an intermediate cylinder member screwed with the lens fixing frame supported movably in the axial direction, and further including a second spring member for constantly urging the intermediate cylinder member forward. Light shielding structure of the cylinder. 3. The light-shielding structure for a retractable lens barrel according to claim 1, wherein at least a lens group fixed to the lens fixing frame is a variable power lens group.

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