JP3335274B2 - Shutter unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter unit used for a lens shutter camera.

[0002]

2. Description of the Related Art As an initial position detection method of a movable lens such as an AF lens provided in a lens barrel,
There is known a method in which a light shield is provided on a member that moves integrally with a movable lens, and the light shield is detected by a photo interrupter to detect an initial position.

According to this method, since the light shield moves together with the movable lens, it is necessary to secure a passage in the lens barrel in which the light shield can move over the entire movable range of the movable lens. There is a problem that the lens barrel becomes large by the space for securing the body movement path.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is intended to provide a shutter unit having a movable lens which requires initial position detection.
The configuration is simple, does not require much space, and is possible
An object of the present invention is to provide a shutter unit that also has excellent durability of a moving lens driving mechanism .

[0005]

The shutter unit SUMMARY OF THE INVENTION The present invention provides the unit body has a shutter blade; formed in the unit main body
Slide bearing in the direction parallel to the optical axis
A drive gear that is rotatably supported by restricting movement in the optical axis direction
Ya; phase to the slide bearing section of the unit body; variable dynamic lens frame
Movably engages, one end is fixed to the movable lens frame
Slide shaft; screwed with drive gear of unit body
Then, the movable lens frame is slid according to the forward / reverse rotation of the drive gear.
One end is moved in the optical axis direction along the id shaft.
A feed screw fixed to the movable lens frame; a light shielding body movably supported in the optical axis direction separately from the movable lens frame in the unit main body ; and an optical path fixed to the unit main body and opened and closed by the light shielding body. An encoder consisting of a photo interrupter; a feed screw and a slide shaft
Each other end of the bridge is bridged by a single support member.
In the material, the movable lens frame is
When the light reaches the vicinity of one moving end, the light shielding body is moved to
And a dog member for closing an optical path of the photo interrupter .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments. In this embodiment, the present invention is applied to a zoom lens barrel provided in a lens shutter type zoom lens camera shown in FIG.
The concept of this zoom lens camera will be described.
Zoom lens barrel 1 provided in this zoom lens camera
0 is the first movable barrel 20, the second movable barrel 19, and the third
The moving barrel 16 having three moving barrels (extending barrels).
This is a step-out type zoom lens barrel. The lens configuration of the zoom lens barrel 10 includes two groups, a front lens group L1 and a rear lens group L2.

[0007] The camera body includes an overall movement motor control means 60, a rear group movement motor control means 61, and a zoom operation means 6.
2, shutter release means 63, distance measuring device 64, photometric device 65, and AE motor control means 66 are provided.

The overall movement motor control means 60 includes a zoom operation means 62 such as a zoom operation lever provided on the camera body.
Is operated (that is, at the time of zooming operation), the movement command for moving the zoom lens composed of the front group lens L1 and the rear group lens L2 from the wide side to the tele side to the whole movement motor 25, or from the tele side. A movement command for moving to the wide side is given. The focal length is changed by the operation of the zoom operation unit 62 by the photographer, and is set to an arbitrary focal length. The image magnification of the finder field is changed in conjunction with the focal length change by the zoom operation means 62. Therefore, the photographer can know the change in the focal length due to the operation of the zoom operation unit 62 by observing the change in the image magnification of the finder field. Also, the zoom operation means 62
The focal length set by the operation of
It can be recognized by numerical values displayed on a display panel (not shown).

When the shutter release means 63 is operated, the whole-group moving motor control means 60 is driven by the rear-group moving motor control means 61.
And drives the overall movement motor 25 to move the front group lens L
The rear lens L2 is moved backward with respect to 1 to focus on the subject. The shutter release means 63 is composed of a release button.
4 and a photometric command to the photometric device 65 are provided, the focusing operation is performed by pressing the shutter two steps, and the shutter 27 of the AF / AE shutter unit (shutter unit) 21 is controlled via the AE motor control means 66. Make it work. The shutter 27 receives the photometric output from the photometric device 65 and opens its shutter blade 27a for a predetermined time.

When operated, the zoom operation means 62 drives the whole movement motor 25 to move the front lens group L1 and the rear lens group L2 integrally. At the same time as this movement, the rear group moving motor 30 may be operated via the rear group moving motor control means 61. However, in the present zoom lens camera, the movement of the front group lens L1 and the rear group lens L2 by the zoom operation means 62 is not performed. This is not performed by the conventional concept of zooming in which the focal length is continuously changed without moving the position of the focal point. That is, when the zoom operation means 62 is operated, only the whole movement motor 25 is operated, and the front group lens L
1 and the rear group lens L2 are moved back and forth without changing the air gap between them, and the front group lens L1 and the rear group lens L2 are operated by operating both the overall movement motor 25 and the rear group movement motor 30. Can be moved while changing the air gap between the two.

In the aspect of the present invention, a subject at a specific distance is not always in focus, but a lens shutter type camera such as the present camera which does not observe an image by a photographing optical system,
There is no problem at all when it is only necessary to focus when the shutter is released. Further, in the aspect, the front lens group L1 and the rear lens group L2 are moved while allowing the focal position to move, and both the entire moving motor 25 and the rear group moving motor 30 are operated at the time of shutter release to focus.

After executing any one of the above-described control modes in response to the operation of the zoom operation means 62, the shutter release means 63 is operated in at least a part of the focal length range of the focal length set by the zoom operation means 62. When this is done, the whole moving motor 25 and the rear group moving motor 30
Are operated to focus on the subject. The amount of movement of the front group lens L1 and the rear group lens L2 by the entire movement motor 25 and the rear group movement motor 30 at this time is not limited to the amount of movement obtained by subject distance information by the distance measuring device 64,
It is determined in consideration of the amount of movement obtained by the focal length information set by the zoom operation means 62. As described above, when the shutter release means 63 is operated and both the overall movement motor 25 and the rear group movement motor 30 are operated to perform the focusing operation, the degree of freedom in controlling the lens position is increased, and the control thereof is performed. Becomes easier.

Note that, theoretically, when the zoom operating means 62 is operated, the entire moving motor 25 and the rear group moving motor 30 are moved.
Without operating any of them, only the view magnification of the finder and the focal length information are changed, and the shutter release means 63
Is operated, the focal length information and the distance measuring device 64
, The front and rear group lenses L1 and L2 are moved to the positions uniquely determined by the focal length information and the subject distance information. It can also be done.

Next, an embodiment in which the zoom lens barrel 10 having the above concept is concretely described mainly with reference to FIGS. 11 and 12. FIG. First, the schematic configuration and operation of the zoom lens barrel 10 will be described.
A second movable lens barrel 19, a third movable lens barrel 16, and a fixed lens barrel block 12 are provided. The third movable lens barrel 16 is screwed to the cylindrical portion of the fixed lens barrel block 12, and moves forward and backward in the optical axis direction with rotation. The third movable lens barrel 16 has a rectilinear guide cylinder 17 whose rotation is regulated and moves inward in the optical axis direction, and the second movable lens barrel 19 rotates relative to the rectilinear guide cylinder 17. While moving back and forth in the optical axis direction. The rotation of the first movable lens barrel 20 is restricted, and the first movable lens barrel 20 advances and retreats in the optical axis direction by relative rotation with respect to the second movable lens barrel 19. The whole moving motor 25 is fixed to the fixed lens barrel block 12, and the shutter mount (unit body) 40 on which the rear group moving motor 30 and the AE motor 29 are mounted is fixed to the first moving lens barrel 20. The front group lens L1 is a lens having a positive power supported by the front group lens support cylinder 34, and the rear group lens L2 is provided with a negative power supported by the rear group lens support cylinder (movable lens frame) 50. Lens.

The fixed lens barrel block 12 fixed in front of the aperture plate 14 of the camera body has a female helicoid 12a and a plurality (4) parallel to the optical axis O on the inner peripheral surface of the cylindrical portion.
Book guide straight groove 12b. An engagement protrusion 17c '(see FIG. 12) formed on the linear guide cylinder 17 is slidably engaged with one of the plurality of linear guide grooves 12b. The straight guide groove 1 with which the engaging projection 17c 'is engaged.
A code plate 13 having a predetermined pattern is provided at the bottom of 2b.
a is fixed. The code plate 13 a is configured as a part of the flexible printed circuit board 13 located outside the fixed lens barrel block 12. Aperture plate 14
Is an aperture 14a for determining an exposure area on the film.
Having.

The cylindrical portion of the fixed lens barrel block 12 has a gear housing portion 12c bulging radially outward and extending in the optical axis direction.
Are formed (see FIG. 7). This gear storage section 12c
, A driving pinion 15 long in the optical axis direction is rotatably housed. The drive pinion 15 has both ends of the shaft 7 rotatably supported by a support hole 4 provided in the fixed lens barrel block 12 and a support hole 31 a provided in the gear support plate 31. The tooth surface of the drive pinion 15 projects from the inner peripheral surface of the fixed lens barrel block 12.

On the inner periphery of the cylindrical portion of the fixed lens barrel block 12,
The third movable lens barrel 16 is screwed. The third movable barrel 16 has a plurality (three) of linear guide grooves 16c parallel to the optical axis O on the inner peripheral surface, and the female helicoid 12a of the fixed barrel block 12 on the outer periphery of the rear end. Male helicoid 16 meshing
a, and an outer peripheral gear 16b (see FIG. 6) that meshes with the drive pinion 15. The drive pinion 15 has an axial length that meshes with the outer peripheral gear 16b in the entire movement range of the third movable barrel 16 in the optical axis direction.

A linear guide tube 17 is supported on the inner periphery of the third movable lens barrel 16 so as to be integrally movable with the third movable lens barrel 16 in the optical axis direction and relatively rotatable around the optical axis. . The rectilinear guide cylinder 17 has a rear end flange portion 1 provided with a plurality (four) of engagement projections 17c protruding radially outward on the rear outer periphery.
7d, and a retaining flange 17e having a smaller diameter than the flange 17d, which is provided with a slight gap in front of the rear end flange 17d. This retaining flange 17
A plurality of notches 17f are formed in the circumferential direction of e.
The third movable lens barrel 16 has a plurality of engaging projections 16d (FIG. 11) projecting inward in the radial direction on the inner periphery of the rear end portion. Positioned in the gap between the flange portions 17d and 17e,
Is connected to the rectilinear guide cylinder 17 by relative rotation with respect to. The rear end face of the straight guide cylinder 17 has an aperture 1
An aperture plate 23 having an opening 23a having substantially the same shape as 4a is fixed. Each engagement projection 17c is formed on a corresponding linear guide groove 12 formed on the inner periphery of the cylindrical portion of the fixed lens barrel block 12.
b is slidably engaged with the member b to restrict rotation. The engagement protrusion 17c ', which is one of the engagement protrusions 17c, is in sliding contact with the code plate 13a fixed to the bottom of the corresponding straight guide groove 12b to generate a signal corresponding to the focal length during zooming. The contact terminal 9 is fixed.

On the inner peripheral surface of the rectilinear guide tube 17, there are two rectilinear guide grooves 17a parallel to the optical axis O, and the rectilinear guide grooves 17 whose circumferential width is slightly wider than the rectilinear guide grooves 17a.
g is formed.

Each straight guide groove 17a has a straight guide member 2
The engaging projections 28a formed on the rectilinear guide member 22 are slidably engaged with the corresponding rectilinear guide grooves 17g. A part of the flexible printed circuit board 6 is passed between the bottom of the straight guide groove 17g and the engagement protrusion 28b. Further, the straight guide cylinder 17 has a plurality of (three) lead grooves 17 penetrating the peripheral wall and inclined with respect to the circumferential direction and the optical axis direction.
b is formed.

A second movable lens barrel 19 is fitted on the inner periphery of the straight guide cylinder 17. The second movable lens barrel 19 has a plurality of (three) lead grooves 19c on the inner peripheral surface, which are inclined in the opposite direction to the lead grooves 17b, and a plurality of radially outwardly protruding (on the rear end). Three) trapezoidal follower projections 19a,
The follower pin 18 located on the follower projection 19a
And This follower pin 18 is
a and a center fixing screw 18b for supporting the ring member 18a on the follower projection 19a. Each follower projection 19a is provided in the corresponding lead groove 1 of the linear guide cylinder 17.
7b so as to be slidable, and each follower pin 18
The movable lens barrel 16 is slidably fitted in the corresponding straight guide groove 16c. Therefore, when the third movable lens barrel 16 rotates, the second movable lens barrel 19 rotates and moves straight in the optical axis direction.

A first movable lens barrel 20 is fitted on the inner periphery of the second movable lens barrel 19. The first movable lens barrel 20 includes a plurality of (three) follower pins 24 provided on the outer periphery of a rear end portion,
It is engaged with the corresponding inner peripheral lead groove 19c, and is guided linearly by the linear guide member 22. The rectilinear guide member 22 has an annular portion 22a and a pair of guide legs 22b extending from the annular portion 22a in the optical axis direction. The inner peripheral surface of the first movable lens barrel 20 and the AF / AE shutter unit 21 The guide leg 22b is inserted between the guide legs so as to be able to guide straight. The linear guide member 22 includes two engagement protrusions 28a (only one of which is shown in the drawing) that protrude outward in the radial direction of the annular portion 22a and slidably engage with the linear guide groove 17a. One engagement projection 28 slidably engaged with the linear guide groove 17g.
b.

The annular portion 22a of the rectilinear guide member 22
The second movable lens barrel 19 is coupled to the rear end portion so as to be integrally movable in the optical axis direction and relatively rotatable around the optical axis. The rectilinear guide member 22 has engagement protrusions 28a, 2
8b, and a retaining flange portion 22c smaller in diameter than the flange portion 22d and provided with a slight gap in front of the rear flange portion 22d. It has a plurality (three) of notches 22e in the direction (see FIGS. 1 and 2). The second movable lens barrel 19 has a plurality (three) of engagement projections 19b (see FIG. 11; only one is shown in FIG. 11) protruding radially inward on the inner periphery of the rear end. Each of the engaging projections 19b is inserted from the corresponding notch 22e, is positioned in the gap between the flange portions 22c and 22d, and is connected to the rectilinear guide member 22 by rotating relative to the rectilinear guide member 22. . With the above configuration, when the second movable barrel 19 rotates in the forward and reverse directions, the first movable barrel 20 moves straight forward and backward with respect to the second movable barrel 19 in the optical axis direction while the rotation is restricted. I do.

At the front end of the first movable lens barrel 20, a barrier device 35 having barriers 48a and 48b is mounted.
An AF / AE shutter unit 2 having a shutter 27 including three shutter blades 27a (FIG. 5) on the inner peripheral surface.
1 is fitted and fixed. The AF / AE shutter unit 21 has a plurality of fixing holes 40a (FIG. 3) formed at equal angular intervals on the outer periphery of the shutter mount 40.
The plurality of follower pins 24 also serve as fixing means for the AF / AE shutter unit 21, and are provided in a pin hole 20 a formed in the first movable lens barrel 20 and the fixing hole 40 a.
The follower pin 24 is fitted and fixed, and the shutter unit 21 is fixed to the first movable lens barrel 20 (see FIG. 4). The follower pin 24 can be fixed by, for example, bonding, screwing, or the like. 41 is the first movable lens barrel 20
This is a decorative plate that is fixed to the front end of the display.

The AF / AE shutter unit 21 is shown in FIG.
12, a shutter mounting base 40, a shutter blade support ring 46 fixed to a rear portion of the shutter mounting base 40, and a rear group supported to be relatively movable with respect to the shutter mounting base 40. A lens support cylinder 50 (rear group lens L2). The shutter mount 40 includes
Lens support ring 34, AE motor 29, rear group moving motor 3
0 is supported. The shutter mount 40 has an annular portion 40f provided with a shooting opening 40d through which the front lens support tube 34 is inserted, and three legs 40b extending rearward from the annular portion 40f. I have. Two of the gaps between the three leg portions 40b are
The pair of guide legs 22b are slidably engaged with each other so as to slidably engage with each other, and are configured as a linear guide 40c that guides movement.

The shutter mount 40 further includes an AE gear train 45 for transmitting the rotation of the AE motor 29 to the shutter 27.
A lens drive gear train 42 for transmitting the rotation of the rear group moving motor 30 to the screw shaft (feed screw) 43; photointerrupters 56 and 57 connected to the flexible printed circuit board 6; Rotating plates 59 and 60 are supported. The rear group moving motor 3 is driven by the photo interrupter 56 and the rotating plate 59.
A rear group moving motor encoder that detects the rotation of 0 is configured, and the photo interrupter 57 and the rotating plate 60
An AE motor encoder that detects the rotation of the AE motor 29 is configured.

Between the shutter mount 40 and the shutter blade support ring 46 fixed to the mount 40, the shutter 2
7, a support member 47 for pivotally supporting the three shutter blades 27a of the shutter 27, and an annular driving member 49 for applying a rotational power to the shutter blades 27a. The annular driving member 49 includes three operation protrusions 49a respectively engaging with the three shutter blades 27a at equal angular intervals. The shutter blade support ring 46 is provided at the front wall with the photographing opening 4.
6a and three support holes 46b provided at equal angular intervals around the photographing opening 46a.
It has a flexure restricting surface 46c that is exposed from 0c and slidably supports the inner peripheral surfaces of the pair of guide legs 22b (see FIGS. 9 and 10).

The supporting member 47 located in front of the shutter blade supporting ring 46 includes a photographing opening 47a facing the photographing opening 46a, and three shaft portions 47b (see FIG. 5) facing the three support holes 46b. (Only parts are shown). Each of the three shutter blades 27a has, at one end, a shaft hole 27b through which the shaft 47b is inserted, and at the other end, a shielding portion that shields the imaging openings 46a, 47a.
An elongated hole 27c is provided between the one end and the other end to allow the operation projection 49a to pass therethrough. The support member 47 includes a shaft portion 47b supporting the shutter blade 27a.
The shutter blade support ring 46 is fixed to the shutter blade support ring 46 in a state of being fitted into the corresponding support hole 46b.

The annular driving member 49 has a gear train 4 on its outer periphery.
5 has a gear portion 49b for receiving rotation from. The support member 47 has three arc grooves 47c in the circumferential direction at positions close to the three shaft portions 47b. The three operation projections 49a of the annular driving member 49 penetrate through the three arc grooves 47c, and the long holes 27 of the respective shutter blades 27a.
c. The shutter blade support ring 46 is inserted from the rear side of the shutter mount 40 while supporting the annular driving member 49, the support member 47, and the shutter 27, and is screwed to the shutter mount 40.

Behind the shutter blade support ring 46, a rear group lens support cylinder 50 that is supported by the shutter mount 40 via slide shafts 51 and 52 so as to be relatively movable is disposed. Shutter mount 40 and rear group lens support cylinder 5
No. 0 is urged to move away from each other by the coil spring 3 fitted on the slide shaft (guide rod) 51, thereby eliminating play between the two. The drive gear 42a provided in the gear train 42
Is restricted from moving in the axial direction, and a female screw is formed on the inner periphery thereof. The rear group lens support cylinder 5
A screw shaft 43 having one end fixed to 0 is screwed together, and the drive gear 42a and the screw shaft 43 constitute a feed screw mechanism. Therefore,
When the rear group moving motor 30 is driven to rotate and the drive gear 42a rotates in either the forward or reverse direction, the screw shaft 43 advances and retreats with respect to the drive gear 42a, and the rear group lens support cylinder 5
0, that is, the rear group lens L2 supported by the support cylinder 50 moves relative to the front group lens L1.

At the front of the shutter mount 40, holding members 53, 55 for holding the motors 29, 30 and the like supported by the shutter mount 40 are screwed. The motors 29 and 30 and the photo interrupters 56 and 57 are connected to the flexible printed circuit board 6 having one end fixed to the shutter mount 40. In a state where the first to third movable lens barrels 20, 19, 16 and the AF / AE shutter unit 21 and the like are assembled, an aperture plate 23 is fixed to the rear end surface of the straight guide tube 17, and the front end of the cylindrical portion 11 , An annular retaining member 33 is fitted.

In the present embodiment, the front lens group L1 and the rear lens group L2 are respectively connected to the AF / AE shutter unit 21.
The AE motor 29 and the rear group moving motor 30 are mounted on the unit 21. According to this configuration, there is an advantage that the supporting structure and the driving structure of the front lens unit L1 and the rear lens unit L2 can be simplified, but at least one of the front lens unit L1 and the rear lens unit L2 is
Shutter mount 40, annular drive member 49, support member 4
7, the zoom lens is realized even if the AF / AE shutter unit 21 including the shutter 27 and the shutter blade holding ring 46 is provided as a separate member and is supported by a support member different from the unit.

Next, the AF / AE shutter unit 21 which is a feature of the present invention will be described in detail. As described above, the AF / AE shutter unit 21 includes a drive mechanism for moving the rear lens group L2 with respect to the front lens group L1. Further, the AF / AE shutter unit 21 includes a detection mechanism for detecting an initial position of the rear lens group L2. This initial position refers to the rear group lens L with respect to the front group lens L1.
In focusing, the rear group lens L2 is moved from the initial position toward the rear of the optical axis O by an amount necessary for focusing with respect to the front group lens L1 during focusing, and after the shutter release is completed, It is returned to this initial position. The rear lens group L2 is different from the front lens group L1 when the power is turned on.
After the shutter release is completed, control is performed such that the initial position is always maintained at the time of storage or the like.

An apparatus for detecting the initial position of the rear lens group L2 provided in the AF / AE shutter unit 21 will be described with reference to FIGS. The rear lens support cylinder 50 is supported by the shutter mount 40 via a pair of slide shafts 51 and 52 so as to be movable along the optical axis. One end of each of the slide shafts 51 and 52 is connected to a shaft support boss 50 b, 5 protruding from the outer peripheral surface of the lens support tube 50.
0c. The slide shaft 51 is provided with a slide bearing 51a (FIG. 1) fixed to the shutter mount 40.
The slide shaft 52 is slidably supported by a guide portion (not shown) formed on the shutter mount 40.

One end of the screw shaft 43 is
It is fixed to a shaft support boss 50a protruding from the outer peripheral surface of the lens support cylinder 50 in the vicinity of the shaft support boss 50b. The screw shaft 43 is screwed to a drive gear 42a rotatably supported on the shutter mount 40 and the shutter 27 and in a state where movement in the axial direction is restricted. When the drive gear 42a is rotationally driven by the rear group moving motor 30, the screw shaft 43 advances and retreats with respect to the drive gear 42a, and the rear lens group L2 supported by the lens support cylinder 50, It moves relative to the group lens L1. In order to eliminate backlash between the screw shaft 43 and the drive gear 42a, the rear group biasing coil spring 3 is fitted to one slide shaft 51 between the slide bearing 51a and the shaft support boss 50b. ing. Rear group biasing coil spring 3
Urges the lens support tube 50 in a direction away from the shutter mount 40 (rearward with respect to the shutter mount 40) to remove backlash.

At the front end of the shutter mount 40, a photo interrupter 301 and a chopper (light shield) 302 are mounted near the holding member 55. The photo interrupter 301 and the chopper 302 constitute an encoder that detects the initial position of the rear lens group L2 with respect to the front lens group L1. Photo interrupter 30
1 is mounted on the flexible printed circuit board 6 and fixed to the shutter mount 40. The chopper 302 is implanted in the shutter mount 40, the front end thereof is slidably supported by a chopper guide shaft 303 supported by the pressing member 55, and a chopper biasing spring ( The shutter mounting table 4 by the urging member 304
It is urged toward 0 (toward the rear of the optical axis O). The chopper 302 includes a chopper plate 302a that enters the slit of the photo interrupter 301. When the chopper 302 is at the retracted position by the urging force of the chopper urging spring 304, the optical path OP of the photo interrupter 301 is opened (FIG. 17), the optical path of the photointerrupter 301 is interrupted when it advances to a predetermined position against the urging force of the chopper urging spring 304 (FIG. 1).
5, the state shown in FIG. 16).

At the front ends of the screw shaft 43 and one of the slide shafts 51, a stopper plate (support member) 3 is provided.
Reference numeral 06 is fixed via a lock washer 305.
The stopper plate 306 is integrally provided with an engagement protrusion 3 provided on the chopper 302 when the rear lens support cylinder 50 advances.
A chopper pressing portion (dog member) 306a is formed which comes into contact with 02b and moves forward against the urging force of the chopper urging spring 304. This chopper pressing portion 3
06a contacts the engagement protrusion 302b of the chopper 302 when the lens support cylinder 50 (the rear group lens L2) approaches the shutter mount 40 to a predetermined position, and the chopper 302 is further advanced by the lens support cylinder 50. Is advanced against the urging force of the chopper urging spring 303. When the rear lens support cylinder 50 moves to the initial position close to the shutter mount 40, the chopper plate 302a of the chopper 302 blocks the optical path of the photo interrupter 301. The CPU (not shown) uses the photo interrupter 3
01, it is detected whether or not the rear lens group L2 (the rear lens group support cylinder 50) is at the initial position. When the rear lens group L2 is detected, the rear group moving motor 30 is stopped and the lens with respect to the shutter mount 40 is stopped. The further advance of the support cylinder 50 is stopped. As a result, the rear group lens L2 can be reliably stopped at the initial position, and the lens support tube 50 collides with the shutter mount 40 or the screw shaft 4
Biting between the gear 3 and the drive gear 42a is prevented.

Further, an O-ring (buffer member) 307 made of an elastic material such as rubber is fitted to the slide shaft 51 at a portion between the stopper plate 306 and the slide bearing 51a. The O-ring 307 is moved by the rear group moving motor 30 in the lens extension direction ( stopper) for some reason.
When the plate 306 runs away in the direction of approaching the slide bearing 51a (the retreating direction of the rear group lens L2), the lens support cylinder 5
This is a cushioning material for attenuating an impact when stopping at the lens moving end. Lens retracting direction ( stopper plate 3
When 06 runs away in the direction away from the slide bearing 51a (the forward direction of the rear group lens L2), the rear group biasing coil spring (lens frame biasing spring) 3 decelerates near the lens moving end, and stops when it stops. Shock is buffered. The O-ring 307 and the rear group biasing coil spring 3 also prevent the screw shaft 43 from biting between the drive gear 42a and the like.

The present zoom lens camera operates as follows. When the power switch (not shown) is turned on while the zoom lens barrel 10 is in the lens retracted state shown in FIG. Then, this rotation is transmitted to the drive pinion 15 via the gear train 26 supported by the support portion 32, and the third
Since the movable lens barrel 16 is rotated in the extending direction, the second movable lens barrel 19 and the first movable lens barrel 20 are slightly extended in the optical axis direction together with the third movable lens barrel 16, and the camera widens the zoom lens. The camera is ready for shooting at the end.

In this photographing enabled state, when the zoom operation means 62 is operated to the telephoto side, the whole movement motor 25 is driven to rotate in the forward direction via the whole movement motor control means 60, and is driven via the drive pinion 15 and the outer peripheral gear 16b. To rotate the third movable barrel 16 in the extending direction. Therefore,
The third movable lens barrel 16 is extended from the fixed lens barrel block 12 due to the relationship between the female helicoid 12a and the male helicoid 16a, and at the same time, the straight guide tube 17 is fixed by the relationship between the engagement projection 17c and the straight guide groove 12b. Block 12
With the third movable lens barrel 16 in a state of not rotating relative to the optical axis, it advances forward of the optical axis. At this time, the second movable lens barrel 19
The follower pin 18 is connected to the lead groove 17b and the linear guide groove 1
By simultaneously engaging with the third movable lens barrel 6c, the second movable lens barrel 6 relatively moves in the same direction as the third movable lens barrel 16 and moves forward in the optical axis with respect to the third movable lens barrel 16. The first movable lens barrel 20 is
Since the linear movement guide member 22 guides the linear movement and the follower pin 24 is moved and guided by the lead groove 19 c, the second movable lens barrel 19 and the AF / AE shutter unit 21 are not rotated relative to the fixed lens barrel block 12. Advances ahead of the optical axis.

While the zoom lens barrel 10 is driven in this manner, the rear group moving motor 30 is not driven, so that the front group lens L1 and the rear group lens L2 are integrated with the optical axis while maintaining a constant distance from each other. (See FIG. 8). The focal length set by the zoom operation unit 62 is displayed by a display unit (not shown).

When the release button is depressed one step at an arbitrary focal length set by the zoom operating means 62, a distance measuring command is given to the distance measuring device 64 and a light measuring command is given to the light measuring device 65, so that the distance measuring and measuring operations are performed. Photometry is started. Thereafter, when the release button is depressed two steps, both the whole moving motor 25 and the rear group moving motor 30 move the moving amount obtained from the subject distance information by the distance measuring device 64 and the focus set by the zoom operating means 62. The AE motor control means 6 moves the front lens group L1 and the rear lens group L2 by a movement amount determined in consideration of the movement amount obtained from the distance information to set the focal length and focus on the subject.
The AE motor 29 rotationally drives the annular driving member 49 in accordance with the subject luminance information from the photometric device 65 via 6 to drive the shutter 27 so as to satisfy a predetermined exposure. After the end of the shutter release, both the overall movement motor 25 and the rear group movement motor 30 are immediately driven, and the front lens group L1 and the rear lens group L2 are returned to the state before the shutter release.

Regarding the movement control of the front lens group L1 and the rear lens group L2 by the two-step pressing of the release button,
More specifically, when the release button is pressed twice,
The rear group moving motor 30 is moved forward by a moving amount determined in consideration of the moving amount obtained by the subject distance information by the distance measuring device 64 and the moving amount obtained by the focal length information set by the zoom operation means 62. The rear lens group L2 is moved backward with respect to the group lens L1. At the same time, the whole moving motor 25 moves the moving distance obtained by the subject distance information by the distance measuring device 64 and the focal length information set by the zoom operation means 62. The front lens group L1 is moved by a movement amount determined in consideration of the movement amount obtained by the above, and the combined focal length of the front lens group L1 and the rear lens group L2 is set to the set focal length and the object is focused. Thereafter, after the shutter release is completed, the rear group moving motor 30 is immediately driven to move the rear group lens L2 toward the front group lens L1 and return to the position before the shutter release.
At the same time, the entire moving motor 25 is immediately driven to return the front lens group L1 to the position before the shutter release.

When the zoom operation means 62 is operated to the wide side, the whole moving motor 25 is driven to rotate in the reverse direction, and
The movable lens barrel 16 is rotated in the retracting direction, and is retracted into the cylindrical portion 11 of the fixed lens barrel block 12 together with the straight guide tube 17. At the same time, the second movable barrel 19 is moved to the third movable barrel 1
The first moving lens barrel 20 is rotated into the moving lens barrel 16 while rotating in the same direction as that of the second moving lens barrel 1.
9 is moved together with the AF / AE shutter unit 21. Also during this retraction drive, the rear group moving motor 30 is not driven, as in the above-described retraction drive. When the power switch is turned off, the zoom lens barrel 10 is retracted to the lens storage position shown in FIG.

As described above, AF / A to which the present invention is applied
According to the E shutter unit 21, the chopper 302 is
The chopper 302 is supported on the shutter mount 40 movably in the optical axis direction without being provided integrally with the member that moves integrally with the movable lens, that is, the rear lens support cylinder 50. When it reaches near the front moving end,
Since the chopper pressing portion 306a moves the chopper 302 to close the optical path OP by the chopper plate 302a and thereby detects the initial position of the rear lens group L2, the chopper 302 extends over the entire moving range of the rear lens group L2. And the amount of movement of the chopper 302 in the direction of the optical axis is minimized. Therefore, the path through which the chopper 302 can move over the entire movement range of the rear lens unit L2 is a zoom lens. It is not necessary to secure the zoom lens in the lens barrel 10, thereby preventing the zoom lens barrel 10 from increasing in size. A stopper having a chopper pressing portion 306a
The plate 306 is connected to the screw shaft 43 and the slide shaft.
Since the support member bridges the front end of the
The front ends of the shafts 43 and 51 are
Strength can be improved. In addition, this strike
An O-ring disposed between the upper plate 306 and the slide bearing 51a.
Of the lens support tube 50 by the ring (buffer member) 307
Reduced impact when moving to the rear end in the optical axis direction
Between the slide bearing 51a and the rear lens support cylinder 50.
To the rear group biasing coil spring 3 for backlash removal
Therefore, the lens support cylinder 50 moves to the moving end in the optical axis direction forward.
Shock when moved is reduced. Therefore, AF / AE
The shutter unit 21 provides a drive mechanism for the rear lens group L2.
Durability can be improved.

In the above embodiment, the present invention is applied to a three-stage extended zoom lens barrel. However, the present invention is not limited to this, and is a one-stage, two-stage or four-stage extended zoom lens barrel. Can also be applied. Further, the present invention can be applied to a lens barrel having an AF function without a zoom function.

[0047]

As described above, according to the present invention, the initial position
For shutter units with movable lenses that require position detection
In addition, the configuration of the movable lens initial position detecting device is simple.
Movable lens drive that does not require much space
It is possible to provide a shutter unit that is excellent in the durability of the structure .

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view showing a part of a zoom lens barrel to which the present invention is applied.

FIG. 2 is a perspective view showing a part of the zoom lens barrel in a state different from FIG.

FIG. 3 is an exploded perspective view showing a part of the zoom lens barrel in an enlarged manner.

FIG. 4 is a perspective view showing a state in which an AF / AE shutter unit of the zoom lens barrel is assembled to a first movable barrel.

FIG. 5 is an exploded perspective view showing main members of an AF / AE shutter unit of the zoom lens barrel.

FIG. 6 is a perspective external view showing a third movable lens barrel of the zoom lens barrel.

FIG. 7 is a front view showing a fixed barrel block of the zoom lens barrel.

FIG. 8 is an upper half sectional view showing a maximum extension state of the zoom lens barrel.

FIG. 9 is an upper half sectional view showing a main part of the zoom lens barrel in a lens housed state.

FIG. 10 is an upper half sectional view showing a main part of the zoom lens barrel in a maximum extended state.

FIG. 11 is an upper half cross-sectional view showing a lens storage state of the entire zoom lens barrel.

FIG. 12 is an exploded perspective view showing the entire zoom lens barrel.

FIG. 13 is a block diagram showing a control system for controlling the operation of the zoom lens barrel.

FIG. 14 is an exploded perspective view showing a main part of the zoom lens barrel according to the present invention.

FIG. 15 is an enlarged plan view of the main part.

FIG. 16 is an enlarged sectional view of the main part.

FIG. 17 is an enlarged cross-sectional view showing the main part in a state different from FIGS. 15 and 16;

[Explanation of symbols]

3 Rear Group Energizing Coil Spring 6 Flexible Printed Circuit Board 10 Zoom Lens Barrel 21 AF / AE Shutter Unit (Shutter Unit) 27a Shutter Blade 40 Shutter Mounting Base (Unit Body) 42a Drive Gear 43 Screw Shaft (Feed Screw) 50 Rear Group Lens support cylinder (movable lens frame) 50a 50b Shaft support boss 51 52 Slide shaft 51a Slide bearing 55 Holding member 301 Photointerrupter 302 Chopper (light shield) 302a Chopper plate 302b Engagement protrusion 303 Chopper guide shaft 304 Chopper biasing spring (with 305 Lock washer 306 Stopper plate (Support member) 306a Chopper pressing portion (Dog member) 307 O-ring L1 Front group lens L2 Rear group lens OP Optical path

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-232543 (JP, A) JP-A-2-310549 (JP, A) JP-A-6-160691 (JP, A)

Claims (5)

(57) [Claims] 1. A unit body having shutter blades; a slide formed in the unit body in a direction parallel to an optical axis.
The bearing unit and the unit body regulate the movement in the optical axis direction.
Rotatably supporting the driving gear; variable dynamic lens frame; unit engaged movable relative to the slide bearing section of the main body
The slide with one end fixed to the movable lens frame
Shaft; screwed with the drive gear of the unit body,
Move the movable lens frame along the slide shaft according to the reverse rotation
One end to the movable lens frame
Photointerrupter having a light shield is a movable lens frame supported by the movable separately in the optical axis direction及beauty the unit body, an optical path which is opened and closed by the fixed and the light blocking members in the unit body; fixed feed screw encoder consisting of; comprises a single supporting each other end of the feed screw and the slide shaft
The movable lens frame is connected to the unit body by the bridging member.
When it reaches the vicinity of one moving end in the optical axis direction with respect to
Move the light shield to change the optical path of the photointerrupter.
A shutter unit comprising a closing dog member . 2. The shutter unit according to claim 1, wherein said support member and a slide bearing of said unit main body.
Between the bearings to bring the support member closer to the slide bearing.
Shock absorber that absorbs shock when moving the movable lens frame to the moving end
Shutter unit provided with a material . 3. The shutter unit according to claim 1, wherein the movable member is provided around the slide shaft.
Inserted between the moving lens frame and the slide bearing to support the above
A movable lens frame in the direction to bring the member closer to the slide bearing
A lens frame biasing spring for biasing the support member , and a movable end for moving the support member away from the slide bearing portion.
When the moving lens frame moves, the resistance of the above-mentioned lens frame urging spring
A shutter unit whose movable lens is decelerated by resistance . In the shutter unit according to claim 4 according to any one of claims 1 to 3, the light shielding body, a shutter unit which is biased toward the normally movable lens frame side by the biasing member. 5. A shutter unit according to any one of claims 1 to 4, the shutter unit is mounted on a lens barrel having a front lens group and the rear lens group, the front group lens the unit the shutter unit is fixed relative to the body, the rear lens group is supported by the said movable lens frame.