JP2006349846A - Lens barrier driving mechanism, camera, digital camera, personal digital assistant device and image input device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrier driving mechanism capable of achieving the light-weighting and the miniaturization of a camera. <P>SOLUTION: In the lens barrier driving mechanism which drives a lens barrier 8 to open/shut the aperture part for photography 9a of a front cover 9 having the aperture part 9a, the lens barrier 8 is driven and coupled with a cylindrical cam 5 which moves moving lens holding frames 3 and 4 holding a moving lens arranged in a finder frame 2 and provided to freely move back and forth in the finder frame 2 back and forth, and is driven to open/shut by the driving force of the cylindrical cam 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera lens barrier driving mechanism and a camera, and more particularly to a camera lens barrier driving mechanism and a camera for driving a lens barrier for protecting a photographing lens of a camera having a finder frame.

If a finger touches the surface of the camera's taking lens or if foreign matter such as dust adheres to it, the optical performance of the taking lens may be temporarily or permanently deteriorated. In order to solve such problems, a lens barrier is provided on the front of the photographic lens. When the camera is not in use, the lens barrier is closed and the photographic lens opening is closed to shield the photographic lens from outside air and external force. is doing. When the camera is used, the lens barrier is opened and retracted to the non-photographing area of the photographing lens so that photographing can be performed.
Such a device for opening and closing the lens barrier can reduce the weight of the camera by sharing its drive source with other parts, and therefore, various devices are devised for each camera model. .
For example, Patent Document 1 discloses a camera barrier opening / closing mechanism configured such that the power of a zoom motor is transmitted through a planetary gear mechanism to a gear train connected to the zoom motor and a barrier opening / closing mechanism. Is disclosed.
In Patent Document 2, the focus adjustment device is configured to be movable out of the imaging region. By moving the focus adjustment device out of the imaging region, the zooming device is opened and closed from the zooming device driving mode. A camera having a lens barrier that can be switched to a driving mode is disclosed.
Further, Patent Document 3 discloses a lens barrier drive for a camera in which a finder lens and a lens barrier are driven by the same drive source by a driving force of a cam member slidably disposed on an outer peripheral surface of a fixed cylinder. A mechanism is disclosed.
Japanese Patent No. 3375551 JP-A-6-22203 Japanese Patent No. 3509578

However, in the case of Patent Document 1, adding a camera barrier opening / closing mechanism to make the structure complicated not only tends to cause a malfunction, but also hinders downsizing of the camera and increases cost.
In the case of Patent Document 2, when the focus adjustment device is moved out of the imaging region, the amount of movement must be increased, which not only increases the size in the optical axis direction but also increases the accuracy of position control of the imaging lens. Directly affects the focusing accuracy, so that the operation of the driving source of the focusing mechanism has to be controlled with high accuracy.
In the case of Patent Document 3, if the cam member is slidably disposed on the outer peripheral surface of the fixed cylinder, there is a problem that the radius of the fixed cylinder substantially increases and the size of the camera also increases. .
The present invention has been made in view of the above points, and an object of the present invention is to provide a lens barrier driving mechanism capable of reducing the weight and size of the camera and a camera equipped with the lens barrier driving mechanism.

In order to achieve the above object, a lens barrier driving mechanism according to a first aspect of the present invention includes a cover having a photographing opening on the front surface, a lens barrier that opens and closes the photographing opening, and the cover. An arranged finder frame, a movable lens holding frame that is supported so as to be movable back and forth in the optical axis direction in the finder frame, and that holds the moving lens, and the moving lens by engaging with the moving lens frame and rotating. In an optical apparatus including a cylindrical cam that moves a frame back and forth and a lens barrier drive mechanism that opens and closes the lens barrier, the lens barrier drive mechanism drives the lens barrier to open and close by the rotational driving force of the cylindrical cam. It is characterized by having the structure to do.
According to a second aspect of the present invention, in the first aspect, the cylindrical cam is attached to a finder frame.
According to a third aspect of the present invention, in the first or second aspect, the lens barrier is biased in an opening or closing direction by a biasing force of a spring.
According to a fourth aspect of the present invention, in the first, second, or third aspect, the driving force of the cylindrical cam is obtained from a lens barrel driving mechanism.
A camera according to a fifth aspect of the present invention includes the lens barrier driving mechanism according to any one of the first, second, third, or fourth aspect.

A digital camera according to a sixth aspect of the invention includes the lens barrier driving mechanism according to any one of the first, second, third, and fourth aspects.
A portable information terminal device according to a seventh aspect of the invention includes the lens barrier drive mechanism according to any one of the first, second, third, or fourth aspect.
An image input device according to an eighth aspect of the present invention includes the lens barrier driving mechanism according to any one of the first, second, third, and fourth aspects.
A lens barrier driving mechanism according to an invention of claim 9 includes a cover having a photographing opening on a front surface, a lens barrier for opening and closing the photographing opening, a finder frame disposed in the cover, and the finder. A movable lens holding frame that is supported in the frame so as to be movable back and forth in the optical axis direction, and that holds the moving lens; a cylindrical cam that engages and rotates with the moving lens frame to move the moving lens frame back and forth; In an optical apparatus comprising a lens barrier driving mechanism that opens and closes the lens barrier, the lens barrier driving mechanism includes a lens barrier driving member that is drivingly connected to the lens barrier, and the lens barrier driving member includes: It is characterized in that it is drivingly connected to a cylindrical cam that moves the moving lens holding frame back and forth.
The invention of claim 10 is characterized in that, in claim 9, the cylindrical cam is attached to a finder frame.
An eleventh aspect of the invention is characterized in that, in the ninth or tenth aspect, the lens barrier is biased in an opening or closing direction by a biasing force of a spring.
According to a twelfth aspect of the present invention, in the ninth, tenth, or eleventh aspect, the driving force of the lens barrier driving member is obtained from a lens barrel driving mechanism.
According to a thirteenth aspect of the present invention, a camera includes the lens barrier driving mechanism according to any one of the ninth, tenth, eleventh, and twelfth aspects.
According to a fourteenth aspect of the present invention, a digital camera includes the lens barrier driving mechanism according to any one of the ninth, tenth, eleventh, or twelfth aspects.
According to a fifteenth aspect of the present invention, a portable information terminal device includes the lens barrier driving mechanism according to any one of the ninth, tenth, eleventh, and twelfth aspects.
According to a sixteenth aspect of the present invention, an image input apparatus includes the lens barrier driving mechanism according to any one of the ninth, tenth, eleventh, or twelfth aspects.

  According to the present invention, in the lens barrier driving mechanism that drives the lens barrier that opens and closes the opening of the front cover having the photographing opening, the lens barrier holds the moving lens arranged in the finder frame and also the finder frame. The movable lens holding frame provided in the front-rear direction is driven and connected to a cylindrical cam that is driven to open and close by the driving force of the cylindrical cam. A lens barrier driving mechanism that drives a lens barrier that opens and closes includes a lens barrier driving member that is drivingly connected to the lens barrier, and the lens barrier driving member holds a moving lens disposed in the finder frame and is moved back and forth with respect to the finder frame. By being connected to a cylindrical cam that moves the movable lens holding frame provided movably back and forth, Lightweight camera can be made compact and cost.

The lens barrier driving mechanism of the present invention will be described below with reference to the drawings. In addition, all the matters described in the following invention and drawing are only examples, and do not limit the technical scope of the present invention.
FIG. 1 is an exploded perspective view of a camera provided with a lens barrier driving mechanism according to the first embodiment of the present invention. 2 is a perspective view of a finder frame 2 described later, and FIG. 3 is a development view of a cylindrical cam 5 described later. 4 is a front view of the camera with the lens barrier 8 closed, and FIG. 5 is a front view of the camera with the lens barrier 8 opened. FIGS. 6A, 6B, and 6C are three views from the back of the camera with the lens barrier closed, and FIG. 7 is a rear view of the camera with the lens barrier 8 opened. is there.
A finder frame 2 is provided on the inner upper part of the camera body (rear cover) 1, and movable lens holding frames 3 and 4 (see FIG. 2) are provided in the finder frame 2 so as to be movable back and forth. ing. A cylindrical cam 5 for moving the moving lens holding frames 3 and 4 back and forth is provided beside the finder frame 2.
The camera body 1 (rear cover) 1 and the front cover 9 constitute a cover.
When the user looks inside the finder frame 2 from the outside of the eyepiece 2a, a light image incident from each lens held by each movable lens holding frame 3, 4 is viewed via a mirror (not shown). be able to. Each moving lens holding frame 3, 4 is advanced and retracted in the optical axis direction by the advance / retreat mechanism, whereby the image from the subject can be scaled.
Cam pins 3a and 4a (see FIG. 2) project from the movable lens holding frames 3 and 4, respectively. The first cam pin 3a includes a linear groove 5b and a non-linear groove 5c formed in the cylindrical cam 5. The second cam pin 4a is fitted into a first groove (see FIG. 3), and the second cam pin 4a is fitted into a second groove (see FIG. 3) including a linear groove 5d and a non-linearly shaped groove 5e formed in the cylindrical cam 5. That is, each pin and each groove constitute an advance / retreat mechanism for each lens frame.
That is, as shown in FIG. 1, a cylindrical cylindrical cam 5 is disposed on the side of the finder frame 2 in parallel with the optical axis and rotatably about the axis, and is formed on the outer peripheral surface thereof. The first and second cam pins 3a and 4b are fitted in the first and second grooves, respectively, and are relatively moved along the grooves.

Since the straight grooves 5b and 5d are formed in parallel to the direction orthogonal to the optical axis direction (vertical direction in FIG. 3), the cam pins 3a and 4a are portions of the straight grooves 5b and 5d when the cylindrical cam 5 rotates. The movable lens holding frames 3 and 4 do not move back and forth in the optical axis direction.
The non-linear grooves 5c and 5e move the movable lens holding frames 3 and 4 back and forth in the optical axis direction so that a subject image having a magnification corresponding to the photographing magnification can be observed from the eyepiece 2a of the finder frame 2.
Therefore, when the cam pins 3a and 4a move along the straight grooves 5b and 5d, respectively, the cam pins 3a and 4a can freely rotate the cylindrical cam 5 without moving back and forth in the optical axis direction. When the cam pins 3a and 4a are moving between the non-linear grooves 5c and 5e, a subject image having a magnification corresponding to the photographing magnification can be observed from the eyepiece 2a of the finder frame 2.
The lens barrier 8 is configured to be movable back and forth from the position where the photographing opening 9a shown in FIG. 4 is closed to the opened position shown in FIG. 5 by an opening / closing mechanism.
The gear portion 5 a formed along one axial edge of the cylindrical cam 5 is disposed so as to mesh with the gear portion 6 a of the first power transmission member 6. The first power transmission means 6 is connected to the second power transmission means 7, and the second power transmission means 7 is connected to the lens barrier 8. When the lens barrier 8 is in a closed state as shown in FIG. 4, the power transmission members 6 and 7 have a notch portion in which a protrusion 7 a provided on the outer periphery of the second power transmission member 7 is provided on the outer periphery of the first power transmission member 6. When the lens barrier 8 is in the open state as shown in FIG. 5, the projection 7 a of the second power transmission member 7 rides on the outer peripheral portion 6 c of the first power transmission member 6. Has been placed. That is, the protrusion 7a is fitted in the notch 6b when in the closed state as shown in FIG. 6, but when the first power transmission member 6 starts to be driven in the opening direction, the protrusion 7a becomes the inner wall of the notch 6b. The lens barrier 8 is opened as shown in FIG. 7 because the second power transmission member 7 is pushed by the pressure and rides on the outer peripheral portion 6c to rotate the second power transmission member 7 in the opening direction.
That is, the gear portion 7b of the second power transmission member 7 is disposed so as to mesh with the gear portion 8a of the lens barrier 8 (see FIGS. 6 and 7). The lens barrier 8 is supported so as to be rotatable about the gear portion 8a. When the gear portion 8a is rotated, the lens barrier 8 is closed so as to cover the photographing opening 9a, and the front cover 9 is photographed. It is possible to move between the open state where the opening 9a is opened. The lens barrier 8 is always urged in the closing direction by an urging member (a torsion spring in this example) 10.

When the lens barrier 8 shifts from the closed state to the open state, the cylindrical cam 5 is driven counterclockwise by a drive member (not shown), and the first power transmission member 6 is driven clockwise. At this time, while the cam pins 3a and 4a are moving in the lens barrier opening / closing region within the range along the linear grooves 5b and 5d of the cylindrical cam 5, the projection 7a of the second power transmission member 7 is the first power transmission member. 6, the rotational movement of the first power transmission member 6 is transmitted to the second power transmission member 7 only within a certain range of rotation angle.
Further, since the gear portion 7b of the second power transmission member 7 is disposed so as to mesh with the gear portion 8a of the lens barrier 8, it is driven to the gear portion 8a of the lens barrier 8 within the range of the certain rotation angle. The force is transmitted, and the lens barrier 8 rotates in the opening direction around the gear portion 8a, so that the photographing opening 9a of the front cover 9 can be opened. Thereafter, since the cam pins 3a and 4a move in the zoom area formed by the non-linear grooves 5c and 5e of the cylindrical cam 5, a subject image having a magnification corresponding to the photographing magnification can be observed from the eyepiece 2a of the finder frame 2.
Conversely, when the lens barrier 8 shifts from the open state to the closed state, the cylindrical cam 5 is driven clockwise (closed direction) by a drive member (not shown), and the power transmission member 6 is driven counterclockwise. While the cam pins 3 a and 4 a are moving in the zoom region of the cylindrical cam 5, the protrusion 7 a of the second power transmission member 7 enters the notch 6 b of the first power transmission member 6. Since the lens barrier 8 is always urged in the closing direction by the urging member 10, the protrusion 7a enters the notch 6b through the gear portions 8a and 7b, and rotates in the closing direction around the gear portion 8a. The photographing opening 9a of the front cover 9 can be closed.

Next, a second embodiment of the lens barrier driving mechanism of the present invention will be described with reference to FIG.
FIG. 8 is an exploded perspective view of a camera provided with a lens barrier driving mechanism according to the second embodiment of the present invention. The second embodiment is substantially the same as the first embodiment in the basic mechanism and operation, but the second embodiment does not have a driving member for driving the cylindrical cam 5 but is not shown in the figure. The gear 11 is rotationally driven by the drive member, and the power transmission member 6 is rotated via the gear 12. Further, the power transmission member 6 and the cylindrical cam 5 are drivingly connected. The gears 11 and 12 and the power transmission member 6 constitute a lens barrier driving member.
In this embodiment, a cylindrical cam 5 that moves the movable lens holding frames 3 and 4 of the finder forward and backward (moves in the optical axis direction) and a lens barrier 8 are connected so as to be able to transmit power, and the lens barrier 8 is driven by the cylindrical cam 5. By opening and closing with force, a driving mechanism dedicated to the lens barrier 8 is not required, and the camera can be reduced in weight, size, and cost.
Further, by attaching the cylindrical cam 5 to the finder frame 2, the cylindrical cam 5 and the finder frame 2 can be made the same unit, and the structure can be further simplified.
Further, by elastically urging the lens barrier 8 in the opening direction or the closing direction, a mechanism for preventing destruction is not required, and the camera can be reduced in weight, size, and cost.
Further, if the driving force of the cylindrical cam 5 is obtained from the lens barrel zoom mechanism, a dedicated driving mechanism for the lens barrier driving mechanism is not required, and the camera can be reduced in weight, size and cost.
Further, when the stroboscopic pop-up is performed with the cylindrical cam 5, a drive mechanism dedicated to the stroboscopic pop-up is not required, so that the camera can be reduced in weight, size and cost.
Also, by integrating each moving lens and each moving lens holding frame 3, 4, the number of parts can be reduced, and the camera can be reduced in weight, size and cost.

It is a disassembled perspective view of the camera provided with the lens barrier drive mechanism which concerns on the 1st Embodiment of this invention. It is a perspective view of a finder frame. It is an expanded view of a cylindrical cam. It is a front view of a camera in a state where a lens barrier is closed. It is a front view of a camera in a state where a lens barrier is opened. It is a three-view figure from the back inside a camera in the state where the lens barrier was closed. It is a rear view inside a camera in a state where a lens barrier is opened. It is a disassembled perspective view of the camera provided with the lens barrier drive mechanism which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  2 Finder frame, 3 and 4 Moving lens holding frame, 5 Cylindrical cam, 8 Lens barrier, 9 Front cover, 9a

Claims (16)

A cover having a photographing opening on the front surface, a lens barrier that opens and closes the photographing opening, a finder frame arranged in the cover, and supported in the finder frame so as to be movable back and forth in the optical axis direction. A moving lens holding frame that holds the moving lens, a cylindrical cam that moves the moving lens frame back and forth by engaging with the moving lens frame, and a lens barrier driving mechanism that opens and closes the lens barrier; In an optical instrument with
The lens barrier driving mechanism is configured to open and close the lens barrier by a rotational driving force of the cylindrical cam.   2. The lens barrier driving mechanism according to claim 1, wherein the cylindrical cam is attached to a finder frame.   3. The lens barrier driving mechanism according to claim 1, wherein the lens barrier is biased in an opening or closing direction by a biasing force of a spring.   4. The lens barrier driving mechanism according to claim 1, wherein the driving force of the cylindrical cam is obtained from a lens barrel driving mechanism.   A camera comprising the lens barrier driving mechanism according to any one of claims 1, 2, 3, and 4.   A digital camera comprising the lens barrier driving mechanism according to any one of claims 1, 2, 3, and 4.   A portable information terminal device comprising the lens barrier driving mechanism according to any one of claims 1, 2, 3, and 4.   An image input apparatus comprising the lens barrier driving mechanism according to claim 1. A cover having a photographing opening on the front surface, a lens barrier that opens and closes the photographing opening, a finder frame arranged in the cover, and supported in the finder frame so as to be movable back and forth in the optical axis direction. A moving lens holding frame that holds the moving lens, a cylindrical cam that moves the moving lens frame back and forth by engaging with the moving lens frame, and a lens barrier driving mechanism that opens and closes the lens barrier; In an optical instrument with
The lens barrier driving mechanism includes a lens barrier driving member that is drivingly connected to the lens barrier, and the lens barrier driving member is drivingly connected to a cylindrical cam that moves the moving lens holding frame back and forth. Lens barrier drive mechanism.   The lens barrier driving mechanism according to claim 9, wherein the cylindrical cam is attached to a finder frame.   11. The lens barrier driving mechanism according to claim 9, wherein the lens barrier is biased in an opening or closing direction by a biasing force of a spring.   12. The lens barrier driving mechanism according to claim 9, wherein the driving force of the lens barrier driving member is obtained from a lens barrel driving mechanism.   A camera comprising the lens barrier drive mechanism according to any one of claims 9, 10, 11, and 12.   A digital camera comprising the lens barrier driving mechanism according to any one of claims 9, 10, 11, and 12.   A portable information terminal device comprising the lens barrier driving mechanism according to any one of claims 9, 10, 11, and 12.   An image input device comprising the lens barrier driving mechanism according to claim 9.

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