JPH063571A - Zoom lens barrel - Google Patents

Abstract

PURPOSE:To realize the reliable actuation even in a zoom lens in which an exposure control member is moved in an optical axis direction by engaging the exposure control member with a guide shaft so that it can move in an axial direction and actuating the exposure control member by the rotation of the guide shaft. CONSTITUTION:A front group lens 17 and a rear group lens 18 are allowed to accurately slide in parallel with the optical axis by the guide shafts 12 and 13. A shutter blade 30 functioning as the exposure control member and a diaphragm 44 can be moved in the axial direction and integrally moved in a rotating direction with the shafts 12 and 13, respectively. Then, the shutter blade 30 and the diaphragm 44 integrally mounted with a front group lens frame 19 are moved to the left side from short focusing time to long focusing time by the shafts 12 and 13, and actuating power for the shutter blade 30 and the diaphragm 44 is transmitted by the shafts 12 and 13, so that the reliability on the actuation is not influenced at any focusing time.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens barrel,
Particularly, the present invention relates to improvement of a zoom lens barrel suitable for use in a compact camera. 2. Description of the Related Art A lens barrel of a so-called mechanical compensation type zoom lens uses a plurality of movable lens groups for zooming and adjusting a focus position and a plurality of cam displacement devices having different displacement amount characteristics. In general, it is a structure that is relatively displaced optically. Particularly, in a compact camera, exposure control members such as shutters and diaphragms are arranged between the front lens group and the rear lens group as a so-called "bitouin shutter", and the operation control of these members is connected by a flexible substrate. Often electrically controlled by a microcomputer in the camera. On the other hand, in a film-integrated camera and a simple focus camera having a simple structure, the shutter is charged by the film winding operation, and the charge state is released by pressing the shutter button to release the spring. A mechanical shutter that controls the shutter speed by force is common. [0007] By the way, these electric shutters are used for a single focus and a long focus.
Even in a zoom lens whose diaphragm position moves in the optical axis direction, there is no problem in structure because it is connected by a flexible substrate, but on the other hand, the cost of the shutter, flexible substrate, and microcomputer in the camera is high, and it is suitable for high-end compact cameras. When trying to construct a low-priced zoom camera, the price of the zoom lens barrel becomes too high. Further, the mechanical shutter has a simple structure and is low in cost, and is effective in a film-integrated camera or the like, but it is difficult to transmit an operating force with a shutter or a zoom lens whose diaphragm position changes. Even if the power is transmitted by a shaft pin or the like, there arises a problem that the reliability of the shutter speed changes between the short focus and the long focus, and the number of parts increases. The present invention has been made in view of the above problems, and provides a low-priced zoom lens barrel which achieves reliable operation even in a zoom lens in which an exposure control member moves in the optical axis direction. It is an object. In order to solve the above-mentioned problems, in the zoom lens barrel according to the invention described in claim 1, the lens frame is slidable on a guide shaft provided in the lens barrel body. In a zoom lens barrel that is supported and linearly regulates the lens frame in the optical axis direction by the guide shaft, an exposure control member is engaged with the guide shaft so as to be integrally rotatable and movable in the axial direction. It is characterized in that the exposure control member can be operated by the rotation of the shaft. In the zoom lens barrel according to the second aspect of the present invention, the lens frame is slidably supported by the guide shaft provided in the lens barrel body, and the guide shaft moves the lens frame in the optical axis direction. In the zoom lens barrel that regulates straight lines,
An operation shaft is provided in parallel with the guide shaft, and the exposure control member is engaged with the operation shaft so as to be integrally rotatable and axially movable, and the exposure control member can be operated by rotation of the operation shaft. It is characterized by having done. Further, in the zoom lens barrel according to the third aspect of the present invention, the exposure control member is a shutter or a diaphragm. According to the present invention, the lens frame is slidably supported by the guide shaft provided on the lens barrel body, and the guide shaft regulates the straight line of the lens frame in the optical axis direction. The exposure control member moves in the axial direction on the guide shaft, and the exposure control member is actuated by the rotation thereof. According to the second aspect of the invention, the lens frame is slidably supported by the guide shaft provided in the lens barrel body, and the guide shaft regulates the straight line of the lens barrel body in the optical axis direction. The exposure control member moves in the axial direction on an operating shaft provided in parallel with the guide shaft, and the exposure control member is operated by the rotation thereof. According to the third aspect of the invention, the exposure control member is a shutter or a diaphragm, and the shutter or diaphragm can be operated by rotating the guide shaft or the operating shaft. An embodiment of the zoom lens barrel of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a camera to which the zoom lens barrel of the present invention is attached. A zoom lens barrel 1 is provided at the center of the camera,
A cartridge chamber 2 and a spool chamber 3 are provided on the left and right of the zoom lens barrel 1. A strobe 4 is provided above the cartridge chamber 2, and an AE photometer 5, a viewfinder 6 and an AF optical system 7 are provided above the zoom lens barrel 1. Since the zoom lens barrel 1 is a box type that is long in the lateral direction and short in the height direction, it does not affect the arrangement of each member provided on the upper portion of the zoom lens barrel 1. FIG. 2 is a plan view of the zoom lens barrel when the focal length is short, FIG. 3 is a plan view of the zoom lens barrel when the focal length is long, and FIG.
Is a side view of the zoom lens barrel seen through from the right side (rear surface of the lens barrel) of FIG. 1, and FIG. 5 is a sectional view of the guide shaft. The exterior 10 of the main body of the zoom lens barrel 1 is formed in a box shape as a whole. Inside the exterior 10, the lens 11 and two guide shafts 12, 13 parallel to the optical axis of the lens 11 are provided. A front arm member 14, a rear arm member 15, a disc cam 16 and the like are provided. The lens 11 is composed of a front lens group 17 and two lens groups before and after the rear lens group 18, and a zoom lens system is constituted by relative displacement of these two lens groups. A front lens group frame 19 holding the front lens group 17 and a rear lens group frame 20 holding the rear lens group 18
Are slidably supported by the guide shafts 12 and 13, respectively. The front arm member 14 is rotatably supported by the fulcrum 21, and the rear arm member 15 is rotatably supported by the armor 10 by a fulcrum 22 so as to rotate in a direction parallel to the optical axis.
Drive pins 23 and 24 are respectively provided at the rotating ends, and the drive pins 23 and 24 are engaged with the groove portion 19 a of the front lens group frame 19 and the groove portion 20 a of the rear lens group frame 20. The groove portion 19a of the front lens group frame 19 and the groove portion 20a of the rear lens group frame 20 are formed to have the same diameter as the drive bins 23 and 24, and the drive pins 23 and 24 are formed in the groove portions 19a and 24 in the direction perpendicular to the moving direction of the lens 11. It is possible to move within 20a. Further, in the middle of the front arm member 14 and the rear arm member 15, the cam groove portion 1 formed in the disc cam 16 is formed.
Engaging pins 25 and 26 that engage with 6a and 16b are provided. The disc cam 16 is rotatably attached to the exterior 10 about a rotary shaft 27, and a gear 28 formed on the outer periphery of the disc cam 16 meshes with a drive gear 29. The drive gear 29 is connected to a motor (not shown) and is rotatively driven in forward and reverse directions. Next, the operation of this zoom lens barrel will be described. When the drive gear 29 is rotated by the motor and the disc cam 16 is rotated counterclockwise, the engagement pins 25 and 26 slide in the cam groove portions 16a and 16b, and the front arm member 14 and the rear arm member 15 are rotated. Is the cam groove 16a
Also, it rotates to the left in the drawing in accordance with the shape of the cam groove portion 16b. Then, the drive pin 23 and the drive pin 24 are fitted in the groove portions 19a and 20a, respectively, so that the front lens group 17 and the rear lens group 18 of the lens 11 are connected to the guide shafts 12 and 1.
3, the front and rear arm members 14 and 15 move forward, and the zoom lens barrel enters the long-focus state as shown in FIG. When moving the lens 11, fulcrums 21, 2
Drive pin 2 from the distance from 2 to the engagement pins 25, 26
Since the distances to 3 and 24 are respectively longer, the movement amounts of the engagement pins 25 and 26 are expanded according to the ratio of the respective lengths, and the front lens group 17 and the rear lens group 18 are expanded in the cam groove 16a. ． It is moved independently with a displacement amount of 16b. Therefore, the small group cam 16 is used to connect the front lens group 17 and the rear lens group 18 to the guide shafts 12 and 1, respectively.
When the motor is rotated in the reverse direction, the disc cam 16 is rotated in the reverse direction, and the front lens group 17 and the rear lens group 18 can be moved backward by the same action. The guide shafts 12 and 13 serve as guides for accurately sliding the two front lens group 17 and the rear lens group 18 in parallel with the optical axis. Each of the guide shafts 12 and 13 has a cross-sectional shape in which a perfect circle is cut out to form cam portions 12a and 13a. A shutter blade 30 as an exposure control member is movable with respect to the guide shaft 12 in the optical axis direction and integrally moves in the rotation direction. The shutter blades 30 are attached so as to be sandwiched by the front lens group frame 19. A shutter base 31 is fixed to the end portion of the guide shaft 12 so as to be integrally rotatable. One end 32 of a coil spring 32 wound around the guide shaft 12 is provided.
a is locked to a fixing pin 33 attached to the exterior 10, and the other end 32b is locked to a locking pin 34 fixed to the shutter base 31, and the coil spring 32 causes the shutter base 31 to always guide the guide shaft 12. The shutter blades 30 are urged in the direction to close them. The shutter base 31 is provided with an operating pin 35, and the operating pin 35 is pushed by the operating claw 37 by moving the shutter operating member 36 in the arrow direction a. The shutter operating member 36 is supported by the support pins 38 and 39 attached to the outer casing 10 in the directions of arrows a and b.
The shutter operating member 36 is urged in the direction of arrow a by a spring 40 so that the shutter 36 is abutted against the stopper 41a of the shutter button 41. This shutter button 41
Is guided by the support pins 42 and 43 attached to the exterior 10 so as to be movable in the directions of arrows c and d. The guide shaft 13 also serves as a rotation restriction so that the two front lens group 17 and the rear lens group 18 do not rotate around the guide shaft 12. A diaphragm 44 as an exposure control member is movable with respect to the guide shaft 13 in the optical axis direction and integrally moves in the rotation direction. The diaphragm 44 is attached to the front lens group frame 19 by a mounting member 45. A diaphragm conversion arm 46 that rotates integrally is provided at the end of the guide shaft 13, and by moving the diaphragm conversion arm 46, diaphragm windows 44a, 44 of different sizes opened on the diaphragm 44.
b is switched. Next, the shutter operation of this zoom lens barrel will be described. The shutter operating member 36 can move in the directions of arrows a and b in FIG. 3, and the moving force to the right is exerted by the spring 40 in the figure, but the stopper 36 a is the stopper 41 a of the shutter button 41.
It is in contact with and locked by the shutter. In this shutter charge state, when the shutter button 41 is pushed in the direction of the arrow c on the lower side, the stopper 36a of the shutter operating member 36 is pushed by the stopper 41a.
The shutter actuating member 36 moves from the spring 4
It moves at high speed in the direction of arrow a by the force of 0. The shutter operating member 36 is provided with an operating claw 37, which kicks the operating pin 35 of the shutter base 31 when the operating claw 37 moves at a high speed. As a result, the shutter base 3
1 and the shutter blade 30 that moves together is a guide shaft 1
Rotate clockwise around 2 to perform shutter opening operation. When the shutter blade 30 is opened, the force of the coil spring 32 works to return the shutter blade 30 to the initial position. That is, the shutter speed depends on the spring force of the spring 40 and the coil spring 32. Further, when the shutter is operated, the lens 11 is positioned by the circular portion of the cross section of the guide shaft 12, so that the lens 11 is locked at the same position regardless of the shutter operation. Next, the diaphragm operation of the zoom lens barrel will be described. The diaphragm conversion arm 46 is connected to a strobe ON / OFF switch on the camera side, and the diaphragm conversion arm 46 causes the diaphragm 44 to integrally rotate about the guide shaft 13. In this way, by moving the diaphragm conversion arm 46, the large diaphragm window 44a opened on the diaphragm 44 is switched to the small diaphragm window 44b, the large diaphragm window 44a is used at the time of stroboscopic photography, and the small diaphragm window 44b is Used during normal shooting. Further, although the guide shaft 13 is rotated by this diaphragm conversion operation, since the lens 11 is prevented from rotating by the circular portion of the cross-sectional shape of the guide shaft 13, it is locked at the same position regardless of the diaphragm conversion operation. As shown in FIG. 5, the guide shafts 12 and 13 have so-called D-cuts formed by cutting one end of a cylinder into a flat surface to form cam portions 12a and 13a, and in this case, the cost of machining parts is low. There are advantages. Further, as shown in FIG. 6, the guide shafts 12 and 13 can also be formed with square grooves 12b and 13b at one end of a cylinder, and in this case, the shutter and the diaphragm can be more reliably rotated. . Further, the shutter blade 30 and the diaphragm 44, which are integrally attached to the front lens group frame 19, move to the left side from the short focus to the long focus by the guide shafts 12 and 13. Since the operating force of 44 is transmitted by the guide shafts 12 and 13, the reliability of the operation is not affected at any focus. Further, the number of parts can be reduced by providing one member called the guide shaft 12 with two functions of restricting the straight movement and transmitting the operation of the shutter blades 30. Similarly, it is possible to reduce the number of parts by providing one member of the guide shaft 13 with two functions of the straight travel regulation and the operation transmission of the diaphragm 44. FIG. 7 is a side view of another embodiment of the zoom lens barrel. In this embodiment, the guide shafts 12 and 13 are supported by the outer casing 10 of the lens barrel body, and the guide shafts 12 and 13 accurately regulate the lens 11 in the optical axis direction. The operating shaft 5 is provided separately from the guide shafts 12 and 13.
0 and 51 are provided in parallel, the shutter member 30 is provided on the operating shaft 50, and the diaphragm 44 is provided on the operating shaft 51, as in the above embodiment, the shutter member 30 and the exposure control member such as the diaphragm 44 are integrally rotatable. These exposure control members are operatively engaged by axially movable engagement by rotation of the operating shafts 50, 51. As described above, in the invention described in claim 1, the lens frame is slidably supported by the guide shaft provided in the lens barrel body, and the optical axis of the lens frame is supported by the guide shaft. In the zoom lens barrel that regulates the straight line in the axial direction, the exposure control member is engaged with the guide shaft so as to be integrally rotatable and movable in the axial direction, and the exposure control member is operable by the rotation of the guide shaft. A low-priced zoom lens barrel that achieves highly reliable operation even in a zoom lens in which an exposure control member moves in the optical axis direction and has a reduced number of parts is obtained. According to a second aspect of the present invention, the lens frame is slidably supported by a guide shaft provided in the lens barrel body,
In a zoom lens barrel in which the guide shaft regulates a straight line in the optical axis direction of the lens frame, an operating shaft is provided in parallel with the guide shaft, and an exposure control member can be integrally rotated with the operating shaft in the axial direction. A low-priced zoom lens mirror that achieves highly reliable operation even in a zoom lens in which the exposure control member moves in the optical axis direction, because the exposure control member can be activated by movably engaging it and rotating the operation shaft. The torso is obtained. According to the third aspect of the invention, the exposure control member is a shutter or a diaphragm, and the shutter or diaphragm can be operated by rotation of the guide shaft or the operating shaft, and the shutter and diaphragm structure is simple.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a camera to which a zoom lens barrel is attached. FIG. 2 is a plan view of the zoom lens barrel when the focal length is short. FIG. 3 is a plan view of the zoom lens barrel at a long focus. FIG. 4 is a side view of the zoom lens barrel seen through from the right side (rear surface of the lens barrel) of FIG. FIG. 5 is a sectional view of a guide shaft. FIG. 6 is a sectional view of another embodiment of the guide shaft. FIG. 7 is a side view of another embodiment of the zoom lens barrel. [Explanation of Codes] 1 Zoom lens barrel 12, 13 Guide shaft 30 Shutter blade 44 Aperture

Claims (1)

Claims: 1. A zoom lens mirror in which a lens frame is slidably supported by a guide shaft provided in a lens barrel body, and the guide shaft regulates a straight line in the optical axis direction of the lens frame. In the barrel, an exposure control member is engaged with the guide shaft so as to be integrally rotatable and movable in the axial direction, and the exposure control member can be operated by the rotation of the guide shaft. . 2. A zoom lens barrel in which a lens frame is slidably supported by a guide shaft provided in a lens barrel body, and the guide shaft regulates a straight line in the optical axis direction of the lens frame. Separately from the above, an operating shaft is provided in parallel, and the exposure controlling member is engaged with the operating shaft so as to be integrally rotatable and movable in the axial direction, and the exposure controlling member can be operated by the rotation of the operating shaft. Characteristic zoom lens barrel. 3. The zoom lens barrel according to claim 1, wherein the exposure control member is a shutter or a diaphragm.