JP2011008140A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent disconnection and separation of barrier blades even if external force is applied to them, the barrier blades being arranged one on top of another with a large aperture opened and closed.SOLUTION: A barrier mechanism includes a main blade means 4 and a sub-blade means 6 in that order in front of a barrier drive means 3 in the axial direction. The mechanism generates pulling force between the barrier drive means 3 and the main blade means 4, and transmits the rotating force of the barrier drive means 3 to the main blade means 4 and the sub-blade means 6 in that order. In the barrier mechanism, the sub-blade means 6 includes a barrier separation preventing means 6e for preventing a barrier closing linking part 4c and a barrier closing linked part 6b from being disconnected and separated from each other.

Description

  The present invention relates to a barrier mechanism and a barrier mechanism that are provided on the front side of a photographing optical system to protect a photographing lens provided in a film camera, a digital camera, and the like and cover a photographing opening so as to be freely opened and closed.

  Conventionally, a film camera using a silver salt film has been widely used, but in recent years, a digital camera capable of capturing an image in a memory without using a film has been rapidly spread. Some digital cameras generally include a barrier mechanism for protecting the front surface of the taking lens barrel from external dust and the like.

  As a conventional lens barrel of this type, for example, the following is known (for example, see Patent Document 1).

  The lens barrel includes a pair of barrier blades that can freely open and close a photographing opening on the front side of the photographing optical system, and the barrier blades are driven to open and close by a barrier driving ring that rotates about an optical axis. . The rotational force of the rotating cylinder is transmitted to the barrier drive ring via the connecting shaft. A barrier closing spring is interposed between the barrier blade and the barrier drive ring. The barrier closing spring constantly abuts the barrier blade on the barrier drive ring and urges the barrier blade in the closing direction to absorb the escape movement of the barrier drive ring with respect to the barrier blade.

  Further, a barrier opening spring that biases the barrier driving ring and drives the barrier blades in the opening direction is interposed between the barrier driving ring and the lens barrel cover. When the rotating cylinder rotates clockwise, the rotational force of the rotating cylinder is transmitted to the barrier drive ring via the connecting shaft, and the barrier drive ring to which the rotational force is transmitted rotates clockwise while charging the barrier opening spring. Rotate. At this time, the barrier blade is rotated counterclockwise following the rotation of the barrier driving ring by the barrier closing spring, and this rotation closes the barrier blade and opens the photographing opening on the front side of the photographing optical system. Is covered.

  On the other hand, when the rotating cylinder rotates counterclockwise, the contact portion between the rotating cylinder and the connecting shaft becomes free, and the barrier drive ring rotates counterclockwise by the spring force of the charged barrier opening spring. . At this time, the barrier blade rotates in the clockwise direction following the rotation of the barrier drive ring, and this rotation opens the barrier blade and opens the photographing opening on the front side of the photographing optical system. When the barrier blades are fully opened, the barrier blades abut against the stopper and further rotation is restricted, and the rotation of the barrier drive ring is stopped.

  In addition, if the barrier blade cannot be rotated in the closing direction due to some obstacle (for example, foreign matter such as sand) during the closing operation, the barrier closing spring is charged by the barrier driving ring when the barrier driving ring tries to rotate in the clockwise direction. Allow clockwise rotation of the drive ring. That is, the barrier closing spring allows the barrier drive ring to move away from the barrier blade. This prevents a mechanical failure from occurring.

  In Patent Document 1, there is a pair of barrier blades. However, if the demand for so-called wide lenses increases in recent years, as the imaging lens has been greatly expanded, there is a case where it cannot be configured as a pair. When the optical system becomes wider in this way, it is necessary to increase the opening on the front surface of the lens. To close the opening, the blades of the barrier become large, and the outer shape of the lens barrel increases.

  Therefore, a method of arranging a plurality of barrier blades has been devised. The contents are shown in Patent Document 2.

JP-A-7-159856 JP 2007-102086 A

  In Patent Document 2, three barrier blades overlap in the thickness direction, but the middle is made of resin and the upper and lower blades are made of metal.

  There is a problem that the blades come off when such a configuration is adopted and, for example, the user touches the barrier blades in the peeling direction or foreign substances enter.

  In order to solve such a problem, in one aspect of the present invention, there is provided barrier means composed of at least four blade portions attached to the front surface of the photographing lens so as to be openable and closable, and barrier drive means for opening and closing the barrier means. The barrier means has a main blade means configured to open and close, and a sub blade means rotating around a rotation shaft means provided on the main blade means, and is provided in the main blade means. A barrier closing interlocking portion interlocked with the barrier closing interlocking means is provided in the sub blade means, and a barrier dropout prevention means is provided in the barrier closing interlocking portion.

  According to the present invention, at least four sheets are configured, and in the barrier in which two sheets overlap in the thickness direction and block the lens opening of the lens barrel, the interlocking between the overlapping barrier blades can be configured to be difficult to come off.

It is a disassembled perspective view of the barrier mechanism in one Example of this invention. It is a front view of the barrier mechanism in one Example of this invention. It is a front view of the barrier mechanism in one Example of this invention. It is sectional drawing of the barrier mechanism in one Example of this invention. It is a perspective view showing operation | movement of the blade | wing of the barrier mechanism in one Example of this invention. It is a front view which shows return operation | movement of the barrier mechanism in one Example of this invention. 1 is a perspective view of a photographing apparatus having a barrier mechanism according to an embodiment of the present invention in a power-off state. 1 is a perspective view of a photographing apparatus having a barrier mechanism according to an embodiment of the present invention in a power-on state. It is a top view of the imaging device which has a barrier mechanism in one Example of this invention. It is a rear view of the imaging device which has a barrier mechanism in one Example of this invention. It is a bottom view of the imaging device which has a barrier mechanism in one Example of this invention. It is a block diagram which shows the principal part of a structure of the digital camera which is an imaging device which has a barrier mechanism in one Example of this invention. It is a flowchart which shows the sequence at the time of imaging | photography from the power ON of the digital camera which is an imaging device which has a barrier mechanism in one Example of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  The barrier mechanism according to the first embodiment of the present invention will be described below with reference to the drawings.

  7 to 11 show a digital camera as a device including the imaging apparatus according to the present embodiment. The digital camera 18 shown in the present embodiment is a camera having a zoom mechanism that can change the photographing magnification.

  FIG. 7 is an external perspective view showing a state in which the digital camera 18 is turned off. FIG. 8 is an external perspective view showing a state in which the digital camera 18 is turned on.

  9 shows a top view, FIG. 10 shows a rear view, and FIG. 11 shows a bottom view.

FIG. 12 shows the waist configuration of the digital camera 18.
A finder 16 that determines the composition of the subject, an auxiliary light 15 that assists the light source in the case of performing photometric distance measurement, a strobe 17, and a photographing lens barrel member 19 are configured on the front surface of the digital camera of this embodiment.

  A release button 12, a power switch button 14, a zoom switch 13 are arranged on the top surface, and a card battery cover 29 having a tripod mounting portion 28, a memory card drive 42 and a battery insertion portion (not shown) inside is disposed on the bottom surface. Has been.

  Operation buttons 22, 23, 24, 25, 26, and 27 are arranged on the back, and various function switching can be performed. A display 21 made of LCD and a viewfinder eyepiece 20 are disposed.

  The display 21 is image display means, and displays image data stored in the memory 40 and image data read from the memory card on the screen.

  The control unit includes a CPU 46, a ROM 45, and a RAM 47, and various components such as a release button 12, operation buttons 22 to 27, a display 21, a memory 40, and a memory card drive 42 are connected via a bus 44.

  A zoom motor 30 and a focus motor 31 are connected to the drive circuit 43 connected to the control system via the bus 44. In addition, a shutter driving unit 32, an aperture driving unit 34, an image sensor 36 such as a CCD or a CMOS, and a strobe 17 are connected. Each drive is controlled by a signal from the control system.

  The ROM 45 stores a program for controlling each functional component described above. The RAM 47 stores data necessary for each control program.

  The analog signal processing unit 37 performs analog processing on the captured image data and outputs it to the A / D conversion unit 38. The A / D converter 38 converts the captured analog data into digital data. This digital data is output to the digital signal processing unit 39, where the digital data is processed. Finally, the digital data is stored in the memory 40.

  The data stored in the memory 40 is subjected to compression processing such as JPEG or TIFF by the compression / decompression unit 41 by the operation of the operation button 23, and is output and stored in the memory card.

  The image data stored in the memory 40 and the image data stored in the memory card drive 42 are decompressed by the compression / decompression unit 41. The processed image data can be displayed on the display 21 via the bus 44. When the user views the data on the display 21 and determines that the image is unnecessary, the user can delete the image by operating the operation button 25.

  Next, the configuration of the barrier mechanism provided in the photographing lens barrel 19 provided in the digital camera 18 according to this embodiment will be described.

  FIG. 1 shows an exploded perspective view of the barrier mechanism. FIG. 2 shows a front view of the barrier mechanism.

  FIG. 3a shows the barrier closed state, and FIG. 3b shows the barrier open state. FIG. 4 is a sectional view. In this embodiment, the barrier blades are composed of six sheets.

  The photographic lens 1 has an outer periphery held by the photographic lens holding unit 10 and is inserted into an opening-shaped photographic lens holding unit 2 b provided at the center of the base unit 2. Here, the photographing lens holding part 10 is bonded and fixed to the base part 2, and the adhesive is applied behind the optical axis of the photographing lens holding part 2b shown in FIG.

  The barrier mechanism is held in front of the optical axis of the photographing lens 1 incorporated in the base portion 2.

  A barrier blade is disposed on the barrier driving unit 3 so as to be in contact therewith. This comprises at least four blade portions 4 and 6 attached to the front surface of the photographing lens 1 so as to be openable and closable.

  The pair of main blade portions 4 are provided with shaft-shaped main blade rotation columns 4 a and are inserted into barrier rotation holes 2 a provided in the base portion 2. The main blade portion 4 is provided with a barrier driven portion 4d so that the main blade portion 4 can come into contact with the barrier interlocking portion 3b provided in the barrier driving portion 3.

  A barrier drive spring 5 is incorporated between the main blade portion 4 and the spring holding portion 3a provided in the barrier drive portion 3 so as to pull each other.

  A rotation shaft portion 4b is provided directly behind the main blade rotating column 4a of the main blade portion 4, and is installed so as to overlap the sub blade portion 6 and the second sub blade portion 7 in this order.

  The shaft hole portion 6c provided in the first sub blade portion 6 and the shaft hole portion 7a provided in the second sub blade portion 7 are inserted into the rotation shaft portion 4b.

  Finally, the barrier cover portion 8 is fixed to the base portion 2, and the barrier cap portion 9 is held from above.

  The rotating shaft portion 4b is inserted into the shaft hole portion 8a provided in the barrier cover portion 8, and is mutually overlapped in the optical axis direction, and the sub blade portions 6 and 7 are tilted or kinked by some operation. Even if it operates, it is prevented from falling off the rotating shaft 4b. Finally, since the shaft hole portion 8a is covered with respect to the appearance by the barrier cap portion 9, it cannot be seen from the outside.

  When the barrier mechanism is closed, the barrier driving portion 3 is rotated counterclockwise in FIG. 3 by the external force of the lens barrel, and the main blade portion 4 is also rotated clockwise by the spring force of the barrier driving spring 5. The barrier closing interlocking portion 4c provided at the tip of the main blade portion 4 interlocks the barrier closing interlocking portion 6b provided at the tip of the sub blade portion 6 in the barrier closing direction. Further, the second sub blade closing interlocking portion 6d provided in the sub blade portion 6 interlocks the second sub blade closing interlocking portion 7b provided in the second sub blade portion 7 in the barrier closing direction. In this way, the interlocking force is transmitted to the barrier blades in order, and the barrier mechanism is closed.

  Even if only the barrier blades are forcibly opened in the barrier closed state, the barrier blades are automatically urged in the closing direction by the force of the barrier drive spring 5, so that they automatically return.

  Next, when the barrier mechanism is opened, the barrier drive unit 3 is released from the external force of the lens barrel and is rotated in the clockwise direction by the balance of the spring force of the barrier drive spring 5. The barrier interlocking part 3b of the barrier driving part 3 abuts on the barrier driven part 4d provided in the main blade part 4, and rotates the main blade part 4 counterclockwise. The sub blade opening interlocking portion 6 a provided in the sub blade portion 6 is spread by the side surface of the main blade portion 4, and the second sub blade opening interlocking portion 7 c provided in the second sub blade portion 7 by the side surface of the sub blade portion 6. Will be spread. As a result, the barrier blade is opened.

  At this time, the second auxiliary blade opening interlocking portion 7c comes into contact with the barrier blade stopping portion 2c provided in the base portion 2 and becomes a mechanical stopper.

  The base part 2 is provided with a lens barrel follower 11, and the lens barrel follower 11 is moved in the front-rear direction in the optical axis direction by rotation of a cam ring (not shown), and the base part 2 is operated. In conjunction with the movement of the base portion 2 in the optical axis direction, the barrier blades operate when the barrier driving portion 3 receives rotation at a predetermined location.

  In this embodiment, the main blade portion is made of resin, and the sub blade portion is made of metal. In this way, the thickness from the photographing lens 1 to the front surface of the barrier cover 8 can be minimized, and the camera can be thinned. Of course, it is also possible to configure the sub blade portion from resin.

  By adopting the above configuration, the barrier mechanism is not complicated, and even if the opening is large, the lens barrel diameter can be reduced, and a barrier mechanism with a thinner thickness can be configured.

  Here, when an external force acts on the barrier blade in the direction A in FIG. 2 and a load is applied to the sub blade portion 6, the connection between the barrier closed interlocking portion 4c and the barrier closed interlocking portion 6b is released. End up. Then, when the barrier cover portion 8 is deformed and floats, the coupling is completely removed, and even when the barrier is opened, the blades interfere with each other and the blades remain in the opening as shown in FIG. End up.

  Therefore, a chamfered barrier closing interlock introduction portion 4e is provided at the tip of the barrier closing interlock portion 4c. Further, a hook-shaped barrier drop-off prevention portion 6e is provided at the tip of the barrier closing interlocking portion 6b. As a result, even if an external force in the direction A is applied, the barrier drop-off prevention unit 6e bites into the barrier closing interlock introduction unit 4e, so that it is difficult to drop off each other.

  Here, as shown in FIG. 5, the shape of the barrier drop-off prevention portion 6e may be a taper shape opposite to the shape of the barrier closing interlock introduction portion 4e, or may be a U-shape so that the drop-off prevention effect can be fully expected. good.

  In consideration of the danger that the U-shaped tip comes in contact with the barrier closing interlock portion 4c and the barrier operation is hindered, the tapered shape is formed.

  Further, the second sub blade portion 6 and the second sub blade portion 7 are provided by providing a tapered second barrier drop-off preventing portion 7e at the tip of the second sub blade closed interlocking portion 7b provided in the second sub blade portion 7. Can be prevented from falling off due to external force.

  By taking the above configuration, it is possible to prevent the interlocking barrier blades from falling off.

  Next, the reason why the chamfered sub blade introduction part 4f is provided on the back surface of the barrier closing interlock introduction part 4e of the barrier closing interlock part 4c will be described. This is because the violently large external force works and the barrier cover portion 8 is greatly deformed, and the connection between the main blade portion 4 and the sub blade portion 6 is dropped, resulting in a state as shown in FIG. 5b. . For example, when the blade remains as shown in FIG. 6, the barrier drop-off prevention portion 6 e is guided into the tapered shape of the sub blade introduction portion 4 f by manually pushing the blade in the direction B. Then, the connection between the main blade portion 4 and the sub blade portion 6 can be restored.

  FIG. 13 is a flowchart from the power-on to the end of photographing of a digital camera which is a photographing apparatus provided with the barrier mechanism of the present invention. When the user turns on the power of the photographing apparatus, the CPU 46 sends a command to the zoom motor drive unit 30 to rotate the lens barrel drive motor by CW. Thereafter, a predetermined operation is performed, and when it is confirmed that the photographing lens barrel portion 19 has moved to the photographing position, it is stopped. At this time, the state of the lens barrel changes from the state of FIG. 7 to the state of FIG.

  Next, when the user turns on the release button 12, photometry is performed to obtain luminance information of the subject. When the obtained luminance information is higher than the predetermined luminance, the diaphragm 35 is caused to enter the optical axis and the amount of incident light is changed. When the obtained luminance information is lower than the predetermined luminance, the diaphragm 35 is not operated and is kept away from the optical axis.

  Thereafter, the focus lens 48 is operated and moved to a position where the subject is in focus, and image capture is started there. Next, the shutter 33 is moved from the open state to the closed state to block the amount of incident light, and the image capture is completed. Thereafter, the diaphragm 35 is retracted from the optical axis, the focus lens 48 is moved to the initial position, and the operation ends.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Shooting lens 2 Base means 2a Barrier rotation hole 2b Shooting lens holding part 3 Barrier drive part 3a Spring holding part 3b Barrier interlocking part 3c Rotating sliding part 4 Main blade part 4a Main blade rotating column 4b Rotating shaft part 4c Barrier closing interlocking part 4d Barrier driven portion 4e Barrier closed interlock introduction portion 4f Sub blade introduction portion 5 Barrier drive spring 6 Sub blade portion 6a Sub blade opening interlock portion 6b Barrier closed interlock portion 6c Shaft hole portion 6d Second sub blade close interlock portion 6e Barrier drop prevention part 7 Second sub blade part 7a Shaft hole part 7b Second sub blade closing cover part 7c Second sub blade cover interlock part 7e Second barrier drop prevention part 8 Barrier cover part 8a Shaft hole part 9 Barrier cap 10 Shooting lens holder 11 Lens barrel follower

Claims (7)

Barrier means comprising at least four blades attached to the front surface of the photographing lens so as to be openable and closable; and barrier driving means for opening and closing the barrier means;
The barrier means includes a main blade means configured to open and close, and a sub blade means rotating around a rotation shaft means provided in the main blade means,
The lens is characterized in that a barrier closing interlocking portion interlocked with the barrier closing interlocking means provided in the main blade means is provided in the sub blade means, and a barrier dropout prevention means is provided in the barrier closing interlocking portion. The lens barrel. Barrier means comprising at least six blades attached to the front surface of the photographing lens so as to be openable and closable; and barrier driving means for opening and closing the barrier means;
The barrier means includes a main blade means configured to open and close, a sub blade means rotating around a rotation shaft means provided in the main blade means, and a second sub blade means,
A barrier closed interlocking portion interlocked with the barrier closing interlocking portion provided in the main blade means, and a second sub blade closing interlocking portion are provided in the sub blade means,
A barrier drop-off prevention means is provided at the tip of the barrier closure interlocking portion, and the tip of the second sub blade closure interlocking portion interlocked with the second sub blade closing interlock portion provided in the second sub blade means. A lens barrel comprising a second barrier drop-off preventing means.   3. The lens barrel according to claim 1, wherein the barrier drop-off preventing means has a U-shape.   3. The barrier mechanism according to claim 1, wherein the barrier drop-off preventing means has a tapered shape.   3. The barrier mechanism according to claim 1, wherein a barrier closing interlock introduction portion is provided at a tip of the barrier closing interlock portion, and the barrier drop-off preventing means is fitted into the barrier closing interlock introduction portion.   5. The barrier mechanism according to claim 4, wherein a sub blade introduction portion is provided on a back surface of the barrier close interlock introduction portion of the barrier close interlock portion provided in the main blade means.   An imaging apparatus comprising the barrier mechanism according to any one of claims 1 to 6.

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