JPH0667261A - Lens barrier and lens barrel - Google Patents

Abstract

PURPOSE:To provide the lens barrier which enables the periphery of the opening part of the lens barrel to effectively be utilized. CONSTITUTION:A blade storage space 125 is provided below the opening part 12a of the internal cylinder 12 of the lens barrel and blades 30 and 31 are stored while put one over the other in the direction of the lens optical axis. A storage space 123 is provided above the internal cylinder opening part 12a positioned on the opposite side to the blade storage space 125 across the lens optical axis. The slack part 5a of a flexible printed circuit board 5 which connects the control circuit 4 of a camera body and a driving device 20 in the lens barrel is stored in the storage space 123. When the lens barrel is not used, the blades 30 and 31 are drawn upward out of the blade storage space 125 and the opening part 12a of the internal cylinder 12 is closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrier for protecting a photographing lens built in a lens barrel of a camera and a lens barrel having the lens barrier.

As a lens barrier built in a lens barrel of a camera, as described in Japanese Utility Model Laid-Open No. 61-119139, a pair of blades are moved in opposite directions in a plane orthogonal to the lens optical axis. It is known to open and close the lens barrel opening.

[0003]

In the above-described conventional lens barrier, since the respective lens blades are retracted from the lens optical axis in opposite directions to open the lens barrel opening, the periphery of the lens barrel opening is reduced. Most of the space is occupied by the storage space of the blades, and the effective use of the periphery of the lens barrel opening is impossible.

An object of the present invention is to provide a lens barrier which can effectively utilize the periphery of the opening of the lens barrel and a lens barrel which uses this lens barrier and has high space utilization efficiency.

[0005]

When the invention of claim 1 is described with reference to FIG. 1 showing an embodiment, a plurality of blades 30 and 31 attached to the lens barrel are provided in the opening of the lens barrel. It is applied to the lens barrier 3 that opens and closes the lens barrel opening 12a by moving it between the closed positions Ps1 and Ps2 that share and covers 12a and the retracted position Po that retracts to the periphery of the opening 12a of the lens barrel. It And the above-mentioned purpose is
Each of the plurality of blades 30 and 31 is provided so as to be movable in the same direction orthogonal to the optical axis of the lens barrel, and when the opening 12a of the lens barrel opens, a blade housing portion 125 provided around the opening 12a. This is achieved by configuring the blades 30 and 31 to be housed in an overlapping manner. Claim 2
The invention is a lens barrel comprising the lens barrier 3 according to claim 1, and is located at a position substantially opposite to the blade housing 125 with respect to the optical axis, around the opening 12a of the lens barrel. And a storage space 12 for the component 5a built in the lens barrel.
3 is formed. A lens barrel according to a third aspect is based on the lens barrel according to the second aspect, and includes a tubular body 12 that can be extended and retracted in the optical axis direction with respect to the camera body.
An electric circuit 20 in the lens barrel attached to the cylindrical body 12,
An electric wiring member 5 for connecting the other electric circuit 4 provided on the camera body side to the electric circuit 20 in the lens barrel is provided, and a flexible slack portion 5a is provided at a part of the electric wiring member 5. The slack portion 5 a is stored in the storage space 123. In the lens barrel of claim 4, the electric wiring member 5 is a flexible printed board.

[0006]

In the lens barrier 3 of claim 1, when the lens barrel is opened, each of the blades 30 and 31 has the opening 12a of the lens barrel.
The lens barrel opening 12a is opened by retracting to the blade housing portion 125 provided around the. The blades 30 and 31 retracted to the blade storage portion 125 overlap each other in the optical axis direction. Claim 2
In this lens barrel, each blade 3 of the lens barrier 3 is placed in the blade housing 125 provided around the opening 12a of the lens barrel.
It is stored so that 0 and 31 overlap each other.
The other component 5a is housed in the housing space 123 on the opposite side of the optical axis with 25. In the lens barrel according to claim 3, the cylindrical body 1
When 2 moves in the optical axis direction and the distance between the electric circuit 20 inside the lens barrel and the other electric circuit 4 changes, the slack portion 5a of the electric wiring member 5 accommodated in the accommodation space 123 corresponding to this distance change. The amount of slack changes to prevent the tensile force and bending force from acting on the electric wiring member 5. In the lens barrel of claim 4,
The lens barrel of claim 3 is obtained by mounting the flexible printed circuit board 5 so that slack is generated in the storage space.

Incidentally, in the section of means and action for solving the above problems for explaining the constitution of the present invention, the drawings of the embodiments are used for making the present invention easy to understand. It is not limited to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the lens barrel of the present embodiment is
A zoom mechanism 1 for moving the first lens group L1 and the second lens group L2 in the optical axis direction for zooming, and a focus mechanism for moving a part of the first lens group L1 in the optical axis direction for focusing. The adjusting mechanism 2 and the lens barrier 3 that opens and closes the opening 12a of the lens barrel are provided.

The zoom mechanism 1 includes an outer cylinder 11 fitted to the inner circumference of a fixed cylinder 10 fixed to a camera body (not shown), an inner cylinder 12 fitted to the inner circumference of the outer cylinder 11, and an inner cylinder 12 thereof. The cam cylinder 13 fitted to the inner periphery of the rear end side of the cylinder 12 is provided. Outer cylinder 1
1 is sandwiched between the fixed cylinder 10 and the front presser ring 14 to restrict movement in the optical axis direction, and a tooth portion 110 formed on the outer periphery of the drive gear 15 is connected to the output shaft of the motor M. They are meshed with each other and are driven to rotate around the optical axis according to the rotation of the motor M. The control of the rotation of the motor M will be described later.

As shown in FIGS. 1, 2, 5, and 6, one straight groove 111 extending in the optical axis direction is provided on the inner periphery of the outer cylinder 11, and a spiral portion 112a twisted around the optical axis. And three cam grooves 112 of the same shape and size are formed, and each cam groove 112 is a cam follower 12 fixed to the outer circumference of the inner cylinder 12.
Engage with 0. The inner cylinder 12 has a rectilinear groove 121 provided on the inner periphery thereof engaged with a rectilinear key 16 fixed to a camera body (not shown) to prevent rotation in the circumferential direction. Therefore, when the outer cylinder 11 rotates while the cam follower 120 is in the cam groove spiral portion 112a, the cam follower 120 is pushed in the optical axis direction and the inner cylinder 12 moves in the optical axis direction. The first lens unit L1 supported by is moved in the optical axis direction.

As shown in FIGS. 1 and 5, the cam follower 130 fixed to the rear end of the cam barrel 13 is engaged with the rectilinear groove 111 of the outer barrel 11, whereby the cam barrel 13 moves around the optical axis. It is rotatable integrally with the outer cylinder 11. Cam tube 13
A lens holder 17 that supports the second lens unit L2 is fitted on the inner periphery of the lens holder. A cam follower 170 is fixed to the outer periphery of the lens holder 17, and these cam followers 17 are
Reference numeral 0 denotes three cam grooves 1 of the same shape and size formed on the cam barrel 13.
31 is engaged. The tip of the cam follower 170 has a cam groove 1
It projects from 31 and engages with three rectilinear grooves 122 formed on the inner peripheral surface of the inner cylinder 12. The cam groove 131 is formed in a spiral groove shape that is twisted in the same direction as the cam groove 112 (see FIG. 6) formed on the inner circumference of the outer cylinder 11, while the rectilinear groove 122 is formed parallel to the optical axis. Therefore, when the cam barrel 13 rotates, the cam follower 170 is pushed out in the optical axis direction by the cam groove 131, and accordingly, the second lens group L2 held by the lens holder 17 moves in the optical axis direction. A conical coil spring 171 is a spring that biases the lens holder 17 toward the film side (upward in the drawing) to prevent rattling of the lens holder 17, and 18 is screwed with the male screw portion 113 of the outer cylinder 11 to form an outer cylinder. 11 is a back adjustment ring for adjusting the position of 11.

The cam grooves 112 and 131 are twisted in the cam directions corresponding to the first and second lens groups L1 and L2 when the outer cylinder 11 is rotated counterclockwise when viewed from the front side of the lens barrel. The lens units L1 and L2 are extended toward the front of the lens barrel by an amount corresponding to the twist angle of the grooves 112 and 131.
Is changed so that the focal length increases as it moves forward while changing its distance. Hereinafter, in the present specification, unless otherwise specified, the rotation direction of each component is represented as viewed from the front side (left side in FIG. 1) of the lens barrel.

As shown in FIGS. 1 and 2, the focus adjusting mechanism 2 is attached to the inner circumference of the inner cylinder 12 and is attached to the inner cylinder 1.
A driving device 20 that moves in the optical axis direction together with 2 and a lens holder 21 that is arranged on the inner periphery of the driving device 20 and holds most of the first lens unit L1. Drive device 2
0 rotates the drive pin 200 around the optical axis by an angle corresponding to the distance signal output from the control circuit 4, and the rotation of the drive pin 200 is the arm 210 integrated with the lens holder 21.
Is transmitted to the lens holder 21 via the lens holder 2
Rotate 1 around the optical axis. When the lens holder 21 rotates, the male screw portion 211 on the outer periphery of the rear end portion of the lens holder 21.
Rotates with respect to the female screw portion 201 on the inner circumference of the drive device 20, whereby the lens held by the lens holder 21 moves in the optical axis direction according to the amount of rotation of the drive pin 200, and the focal length of the lens changes. Adjusted. Reference numeral 22 is a spring for removing an error due to backlash between the male screw portion 211 and the female screw portion 201.

The drive device 20 also drives the aperture / shutter 23 arranged in the first lens unit L1 by the release signal output from the control circuit 4. The opening degree and drive speed of the aperture / shutter 23 are controlled by an exposure signal output from the control circuit 4 to the drive device 20.

The control circuit 4 and the driving device 20 are electrically connected via a flexible printed circuit board (hereinafter referred to as FPC) 5. The FPC 5 is attached to the upper surface of the straight advance key 16 and is routed from the rear end to the tip of the outer cylinder 11 and then connected to the drive unit 20. Driving device 20 and straight key 1
A slack portion 5a is provided in the FPC 5 between the tip of the inner casing 6 and the front end of the inner casing 12, and the slack portion 5a is stored in a storage space 123 (see FIGS. 3 and 4) defined above the opening 12a of the inner cylinder 12. It The slack amount of the slack portion 5a is adjusted so that the slack portion 5a remains even when the inner cylinder 12 is maximally extended from the outer cylinder 11 as shown in FIG.

As shown in FIGS. 1 to 5, the lens barrier 3
Is a pair of plate-shaped blades 30 and 31 and these blades 3.
Drive mechanism 32 for driving 0, 31. As shown in FIGS. 1, 2 and 4, the blades 30 and 31 are arranged so as to be displaced in the lens optical axis direction by approximately the plate thickness, and are fitted into the blade guide groove 124 formed in the inner cylinder 12. It is movably supported in the vertical direction of FIGS. 1 and 4.
The upper blade 30 arranged on the rear side of the blades 30 and 31 has through-grooves 300 extending in the vertical direction at both ends thereof, and these through-grooves 300 have projections 3 provided at both ends of the lower blade 31.
10 is fitted. As a result, when the upper blade 30 is pulled out upward from the open state of FIG. 3, the lower blade 31 is pulled out with a delay, and when the upper blade 30 is pulled up to the uppermost position, the blades 30, 31 are in the inner cylinder as shown in FIG. Opening 12a
Is divided into almost half and closed up and down. When the upper blade 30 is lowered to the lowest position, the blades 30 and 31 are superposed in the lens optical axis direction in the blade storage space 125 defined below the inner cylinder opening 12a as shown in FIG. It is stored and the inner cylinder opening 12a is opened. Thus, the blade storage space 125 forms the retracted position Po of the blades 30 and 31, and the positions where the blades 30 and 31 are pulled out to the uppermost position form the closed positions Ps1 and Ps2 as shown in FIG.

As shown in FIGS. 2-4, the drive mechanism 32.
Is a drive shaft 321 attached so as to extend parallel to the lens optical axis over substantially the entire length of the inner cylinder 12, and the drive shaft 3
21 and a drive lever 322 attached to the tip of the inner cylinder 12, and an intermediate lever 32 pivotally supported by a support shaft 126 integral with the inner cylinder 12.
3 and the support shaft 126 disposed on the back side of the upper blade 30.
And an opening / closing lever 324 pivotally supported by the. As shown in FIGS. 2 and 3, an elongated hole 324a is formed on the tip side of the opening / closing lever 324, and the upper blade 3 is formed in this elongated hole 324a.
The pin 302 fixed to 0 is slidably fitted. Figure 2
And as shown in FIG. 5, the rear end of the drive shaft 321 is the inner cylinder 1.
It projects from 2 and is integrated with the cam follower 325. A dog 32 having an inclined surface 326a on the rear end surface of the outer cylinder 11.
6 is fixed, and this dog 326 engages with the cam follower 325 to rotate the cam follower 325 clockwise when the outer cylinder 11 is rotated clockwise to the maximum extent. At this time, the drive lever 322 rotates clockwise to the position shown by the chain double-dashed line in FIG.

As shown in FIG. 3, a spring 327 is stretched between the opening / closing lever 324 and the inner cylinder 12, and the pulling force pushes the opening / closing lever 324 below the inner cylinder 12. The opening / closing lever 324 and the intermediate lever 323 are the support shaft 1
They are connected by a connecting spring 328 fitted around the outer circumference of the wire 26. As a result, the intermediate lever 32 is pulled by the pulling force of the spring 327.
The pin 323a at the tip of No. 3 is pressed against the tip of the drive lever 322, and the pressing force causes the cam follower 325 to rotate counterclockwise via the drive shaft 321 to cause the dog 326 to rotate.
Pressed against. Along with the rotation of the outer cylinder 11, the dog 32
When 6 moves in the circumferential direction, the drive shaft 321 rotates because the cam follower 325 follows the contour of the dog 326,
Along with this, the opening / closing lever 324 rotates to rotate the upper blade 30.
Moves up and down.

As shown in FIG. 6, the cam groove 112 of the outer cylinder 11 is formed.
A straight line portion 112b orthogonal to the lens optical axis direction is provided on the rear end side.
Are formed. When the cam follower 120 is located on these straight portions 112b, the inner cylinder 12 is not extended even when the outer cylinder 11 is rotated, and the cam follower 325 and the dog 3 are not rotated.
The position of 26 in the optical axis direction of the lens is kept the same. As shown by the solid line in the figure, when the cam follower 120 is at the deepest side of the straight line portion 112b, the cam follower 325 rides on the dog 326 as shown by the solid line in FIG.
When the cam follower 120 moves to the intersection of the straight line portion 112b and the spiral portion 112a, the dog 326 moves to the position shown by the chain double-dashed line in FIG. A linear portion similar to the cam groove 112 is also formed in the cam groove 131 formed in the cam barrel 13, and the lens holder 17 holding the second lens unit L2 is also in the optical axis direction in a range where the inner barrel 12 is not extended. Do not move to. That is, the blades 30 and 31 of the lens barrier 3 are opened and closed by the amount of rotation corresponding to the length of the straight portion 112b.

As shown in FIG. 1, the control circuit 4 includes a connection state of the switches SW1 to SW3 and a photo interrupter 6.
Drive circuit 7 based on the amount of rotation of motor M detected by
A drive signal is output to the drive circuit 7, and the drive circuit 7 rotates the motor M based on the drive signal. When the main switch SW1 is switched from the off state to the on state, the motor M causes the outer cylinder 1 to move.
1 rotates counterclockwise from the position of FIG. 5, and the motor M stops when the cam follower 120 moves to the intersection of the straight portion 112b of the cam groove 112 of the outer cylinder 11 and the spiral portion 112a. When the tele switch SW2 is turned on when the cam follower 120 is in the cam groove spiral portion 112a, the outer cylinder 11 is rotated counterclockwise by the motor M, and the focal length of the lens is increased. When the wide switch SW3 is turned on, the motor M is driven in the reverse direction and the focal length of the lens is reduced. When the main switch SW1 is turned off, the outer cylinder 11 rotates clockwise, and the cam follower 120
The rotation of the motor M is stopped at the time point when is moved to the deepest side of the straight portion 112b of the cam groove (solid line position in FIG. 5).

In the lens barrel having the above-mentioned structure, the outer cylinder 11 is held at the maximum clockwise position when the main switch SW1 is off (FIG. 5). At this time, the cam follower 325 rides on the dog 326, the drive shaft 321 rotates clockwise, the drive lever 322 moves clockwise, and the intermediate lever 323 and the open / close lever 324 move counterclockwise, as shown by the chain double-dashed line in FIG. Rotate. Therefore, the upper blade 30 connected to the lever 324 is pulled out upward, and in conjunction with this, the lower blade 31 is also pulled out, and the inner cylinder 1 is pulled out.
The second opening 12a is closed by the blades 30 and 31.

When the main switch SW1 is turned on, the outer cylinder 11 rotates counterclockwise and the dog 326 separates from the cam follower 325. Therefore, the drive lever 32
2, the intermediate lever 323 and the opening / closing lever 324 are springs 3.
It is rotated to the position shown by the solid line in FIG. As a result, the blades 30 and 31 are drawn into the blade storage space 125 below the inner cylinder 12, and the opening 12a of the inner cylinder 12 is opened.
Is opened to allow shooting at the wide end. Further, when the tele switch SW2 is turned on, the first and second lens groups L1 and L2 are extended forward, the focal length is increased, and it becomes possible to shoot on the tele side. When the inner cylinder 12 is extended, the dog 326 and the cam follower 325 are separated from each other in the optical axis direction of the lens, so that the blades 30 and 31 are still stored in the blade storage space 125.

In this embodiment, the inner cylinder 12 is opposed to the outer cylinder 11.
When the feeding amount of the image changes, the distance between the drive device 20 and the control circuit 4 built in the camera body changes. This change in distance is caused by the slack portion 5 of the FPC 5 stored in the storage space 123.
It is absorbed by the change in the amount of slack in a. Therefore,
Excessive tensile force and bending force do not act on the FPC 5, and the life of the FPC 5 is improved. Here, in order to prevent the FPC 5 from being stretched or bent, it is necessary to secure the storage space 123 as large as possible and give the slack portion 5a a sufficient amount of slack. The storage space 123 is defined as the opening 1 of the inner cylinder 12.
If it is provided outside the periphery of 2a, an increase in the lens barrel diameter and the external dimensions of the camera body cannot be avoided. In this respect, in the present embodiment, the retracted positions Po of all the blades 30 and 31 of the lens barrier 3 are gathered in the blade housing space 125 provided below the inner cylinder opening 12a, and the inner cylinder opening 12a having a margin is created. Since the storage space 123 is disposed above the storage space 123, the circumference of the inner cylinder opening 12a can be effectively used to realize the downsizing of the lens barrel and the camera body, and the storage space 123 can be made sufficiently large to improve the life of the FPC 5. . Moreover, since the blades 30 and 31 are stored in a state of being overlapped with each other in the optical axis direction, the blade storage space 1
25 does not expand in the radial direction, and the diameter of the lens barrel is kept substantially the same as that of the conventional example in which a pair of blades are vertically housed.

In this embodiment, the FP is stored in the storage space 123.
Although the slack portion 5a of C5 is housed, the present invention is not limited to this, and various parts built in the lens barrel may be housed. The number of blades 30 and 31 is not limited to two, and may be three or more. The drive mechanism 32 for the blades 30 and 31 is not limited to the example shown in the figure, and each blade may be driven separately, for example. The wiring member that connects the drive device 20 and the control circuit 4 is not limited to the FPC 5, and various wiring members such as lead wires may be used, and at least the slack portion 5a is made of a flexible material that can be bent and deformed. Just do it. The electric circuit connected by the FPC 5 is not limited to the control circuit 4 and the driving device 20. The zooming mechanism 1 and the focus adjusting mechanism 2 are not limited to the examples shown in the figures, and may be appropriately changed according to the purpose of the lens barrel.

In the above embodiment, the blade storage space 125 is the blade storage portion, the inner cylinder 12 is the cylinder, the drive unit 20 is the lens barrel electric circuit, the control circuit 4 is the other electric circuit, and the FPC 5 is.
Constitutes an electric wiring member.

[0026]

As described above, in the lens barrier according to the first aspect of the present invention, when the lens barrel opening is opened, all the blades are accommodated while overlapping with the blade accommodating portion provided around the lens barrel. It is possible to effectively use the periphery of the lens barrel opening by providing a space for accommodating other components around the lens barrel opening while preventing the lens barrel from expanding in the radial direction. In the lens barrel of claim 2, since the components to be built into the lens barrel are stored in the storage space provided on the side substantially opposite to the optical path with the storage portion of the blade of the lens barrier, the opening of the lens barrel is The surroundings are effectively used, and the lens barrel and the camera are downsized.
According to the lens barrel of the third aspect, a storage space capable of giving a sufficient amount of slack to the electric wiring member while preventing the radial expansion of the lens barrel and the enlargement of the camera body is provided in the lens barrel opening. It is possible to improve the life of the electric wiring member by securing it around. According to the lens barrel of the fourth aspect, the effect of the lens barrel of the third aspect can be obtained only by attaching the FPC with slack in the storage space.

[Brief description of drawings]

FIG. 1 is a vertical sectional view in a lens optical axis direction of a lens barrel according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a development view of the inner peripheral surface of the cam barrel of FIG.

7 is a sectional view showing a state in which a first lens group of the lens barrel in FIG. 1 is extended.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 zoom mechanism 2 focus adjustment mechanism 3 lens barrier 4 control circuit 5 FPC 5a slack part of FPC 11 outer cylinder 12 inner cylinder 20 drive device 30 upper blade 31 lower blade 123 storage space 125 blade storage space Po blade retract position Ps1, Ps2 Closed position of blade

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihide Shiobara 1-1538 Kamikawa, Suwa City, Nagano Nitto Kogaku Co., Ltd. Inside the Kamisuwa Plant

Claims (4)

[Claims] 1. A plurality of blades attached to a lens barrel,
In a lens barrier that opens and closes the lens barrel opening by moving between a closed position that shares and covers the opening of the lens barrel and a retracted position that retracts around the opening of the lens barrel. Each of the plurality of blades is provided so as to be movable in the same direction orthogonal to the optical axis of the lens barrel, and when the opening is opened, each of the blades is placed in a blade storage portion formed around the opening. A lens barrier that is configured so that the two are stacked and stored. 2. A lens barrel comprising the lens barrier according to claim 1, wherein the lens barrel is provided on a substantially opposite side of the opening of the lens barrel with the optical axis interposed between the blade housing portion. A lens barrel, wherein a storage space for a component built in the lens barrel is formed at a position. 3. A cylinder body that can be extended and retracted in the optical axis direction with respect to the camera body, an electric circuit inside the lens barrel attached to the cylinder body, another electric circuit provided on the camera body side, and the lens barrel. An electric wiring member for connecting to an internal electric circuit is provided, a slack portion having flexibility is provided in a part of the electric wiring member, and the slack portion is stored in the storage space. 2. The lens barrel described in 2. 4. The lens barrel according to claim 3, wherein the electric wiring member is a flexible printed circuit board.