JP2005099167A - Shutter for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shutter for a camera provided with two sectors and capable of obtaining a suitable operation even when each of size of respective sectors is made small. <P>SOLUTION: The sector 4 is arranged between a main plate 1 and an intermediate plate 3 and pivoted to the shaft 1c of the main plate 1, and the sector 5 is arranged between an auxiliary plate 2 and the intermediate plate 3 and pivoted to the shaft 1d of the main plate 1. Also, the tip parts are formed short so as not to be overlapped at the time of fully opening an exposure aperture and the sectors 4 and 5 are turned to a shape advantageous for the miniaturization and acceleration of the shutter. While the sectors 4 and 5 are constituted so as to open and close the exposure aperture by being rotated in opposite directions by the reciprocating action of an operation pin 6 inserted to the oblong holes 4a and 5a, at the time of a closing action, their closing is ended roughly at the center of the exposure aperture without interference. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a camera shutter in which an exposure opening is opened and closed by rotating two shutter blades in opposite directions by one driving means.

  The camera lens shutter is a type of shutter that opens and closes a circular exposure opening with shutter blades disposed in the vicinity of the photographing lens. In this type of shutter, one shutter blade opens and closes the exposure opening by its reciprocating rotation, or two shutter blades are straight in opposite directions at the same time with the exposure opening in between. And a plurality of shutter blades (many of five) are reciprocally rotated in the same direction at the same time by a drive ring that rotates about the optical axis, In some cases, the exposure opening is opened and closed, but in recent years, two shutter blades are simultaneously rotated in opposite directions to open and close the exposure opening. This type of shutter is employed in both a silver salt camera and a digital still camera.

  By the way, in the case of a lens shutter, when opening the exposure aperture, it begins to open from the center of the optical axis, and when it is closed, it closes at the center of the optical axis, and the aperture shape that changes during opening and closing operations is as close to a circle as possible. It is supposed to be ideal. Therefore, in the case of a shutter that rotates two shutter blades simultaneously in opposite directions, the opening forming edge of the shutter blade must have a unique curved shape. It was long in the shape of an arc, and even when the exposure aperture was in a fully open state, the tip portions of both were overlapped.

  However, the shutter blade having such a shape has a problem in terms of downsizing and speeding up of the shutter because of its large plane area and large operating area. On the other hand, since the performance of the lens and the performance of the film have improved, it can be opened from the center of the optical axis and closed to the center of the optical axis, or the opening shape that changes during opening and closing operations can be made close to a circle. Rather than doing it, smaller and faster speeds have become more important. In particular, in the case of a digital still camera including a camera for a mobile phone, for which demand has been rapidly increasing recently, such a tendency is strong because only the shutter blade closing operation affects the photographing result. It has become.

Therefore, in order to meet the strong demand for downsizing and speeding up such a shutter, the tip of the shutter blade having the above-mentioned shape is excised and pivotally attached for the purpose of reducing the size and weight of the shutter blade itself. What shortened the length from a part to a front-end | tip part has come to be adopted. However, in that case, if the length of the shutter blades is simply shortened, the tip portions of the two shutter blades do not overlap when the exposure opening is fully opened, and the shutter blades are deformed during the closing operation, and the tip portions are in contact with each other. The two shutter blades have their opening-forming edges crossed sequentially in order from the pivotal part side to the tip part, like the two cutting edge edges of the scissors. It was configured to go. Patent Document 1 discloses an example of such a configuration.
JP 2001-272711 A

  However, as described above, the shutter is configured to open and close the exposure opening by rotating the two shutter blades in opposite directions, and the opening forming edge of the two shutter blades is pivotally attached during the closing operation. Those configured so as to continuously and sequentially intersect from the side toward the tip end portion are provided with at least one bending point at their opening forming edge, as in the shutter blade described in Patent Document 1. Even in such a case, the region where the exposure opening is finally closed is the region farthest from the middle position of the line segment connecting the pivotal portions of the two shutter blades.

  Needless to say, this takes a little longer time from the start of closing to the end of closing than the case where the region near the optical axis is the region where the closing ends. Moreover, it is difficult to say that such a shutter is preferable from the viewpoint of uneven exposure. Furthermore, when it is adopted in a digital still camera, it is difficult to say that it is preferable from the viewpoint of smear phenomenon depending on the type of solid-state imaging device. And these things are improved if it is made to close at the end in the vicinity of an optical axis. Therefore, in the case of the configuration described in Patent Document 1, in such a case, the intersection angle between the opening forming edges of the two shutter blades is set to be negative after the bending point. That is, it is only necessary to make the intersection state opposite to the previous intersection. However, in such a case, when the two shutter blades are deformed during the closing operation, there is a possibility that their tip portions interfere (collision).

  The present invention has been made to solve such a problem. The object of the present invention is to provide a shutter that opens and closes an exposure opening by rotating two shutter blades in opposite directions. Even though the shutter blades are configured so that their tip portions do not overlap when the exposure aperture is fully opened, and the shutter is reduced in size and speed, the shutter blades are not closed when the exposure aperture is closed. It is an object of the present invention to provide a camera shutter that does not interfere.

  In order to achieve the above object, a shutter for a camera according to the present invention comprises two ground planes attached to each other at a predetermined interval, and two blade chambers by partitioning the two ground planes. And an intermediate plate that is separately disposed in the two blade chambers and pivotally attached to one of the two ground plates, each of which has a long hole, and when the exposure opening is fully opened, the tip thereof The two shutter blades formed in a shape that does not overlap each other and one operating pin fitted in both of the long holes, and the two shutter blades are in opposite directions by reciprocating. And a driving source for reciprocating the driving means.

  In this case, each of the two shutter blades may have at least one bending point where each opening forming edge is bent toward the other shutter blade when fully opened. Further, when the driving source is a motor, the driving means is a rotor of the motor, and the operating pin is an output pin of the motor, it is more suitable for reducing the size and cost of the shutter. It will be a thing.

  The present invention relates to a shutter configured to open and close an exposure opening by rotating two shutter blades in opposite directions, and shortening the length from the pivotally mounted portion to the tip portion of the two shutter blades, Even if it is configured so that the tip portions do not overlap when the exposure opening is fully opened, the shutter blades can be closed at substantially the center of the exposure opening without interfering with each other during the closing operation. This is extremely suitable for reducing the size and speed of the shutter.

  Embodiments of the present invention will be described with reference to the illustrated examples. 1 to 4 are all plan views for explaining the embodiment. FIG. 1 shows a fully opened state of the shutter blades, and FIG. 2 shows a closing operation of the shutter blades. 3 shows the state immediately before the exposure opening is started and FIG. 3 shows the state at the moment when the shutter blade has finished closing the exposure opening, and FIG. 4 shows the state where the shutter blade is closed. FIG. 2 to FIG. 4 show the state in which the auxiliary base plate shown in FIG. 1 is removed, although the state where the operation is finished and stopped is shown.

  The present embodiment is a shutter that can be used for both a digital still camera and a silver salt camera. First, the configuration of this embodiment will be described mainly with reference to FIG. The main base plate 1 and the auxiliary base plate 2 are attached to each other with a predetermined interval between them by an appropriate means not shown. Moreover, although both have the external shape on a plane similar shape, in FIG. 1, a part of auxiliary | assistant ground plane 2 is fractured | ruptured and shown.

  The intermediate plate 3 is attached between the main ground plate 1 and the auxiliary ground plate 2 and constitutes two blade chambers between the ground plates 1 and 2, but in FIG. It is shown. The three plate members 1, 2 and 3 are formed with openings 1a, 2a and 3a for a photographing optical path having a circular shape at a substantially central portion. As is well known, of these openings 1a, 2a and 3a, any opening may be used as an exposure opening. In the case of this embodiment, the diameter of the opening 1a is not clear on the drawing. Is smaller than the diameter of the opening 2a to restrict the exposure opening.

  The main base plate 1 is made of synthetic resin, has a long hole 1b, and is provided with two shafts 1c and 1d and two stoppers 1e and 1f on the blade chamber side surface. The shafts 1 c and 1 d pass through holes 3 b and 3 c formed in the intermediate plate 3, and their tips are fitted in holes 2 b and 2 c formed in the auxiliary ground plate 2. Further, the stoppers 1e and 1f have their tips fitted into holes 2d and 2e formed in the auxiliary base plate 2, respectively. Further, the auxiliary ground plate 2 is formed with a long hole 2f having the same shape as the long hole 1b of the main ground plate 1, and the intermediate plate 3 is formed with a long hole 3d larger than the long holes 1b and 2f. ing.

  A shutter blade 4 is disposed in a blade chamber formed between the main base plate 1 and the intermediate plate 3, and is pivotally attached to a shaft 1 c of the main base plate 1. The shutter blade 4 is formed with a long hole 4a and an opening forming edge 4b having an arc shape. A shutter blade 5 is disposed in the blade chamber formed between the auxiliary base plate 2 and the intermediate plate 3 and is pivotally attached to the shaft 1 d of the main base plate 1. The shutter blade 5 has a long hole 5a and an arcuate opening forming edge 5b. In the case of this embodiment, the shutter blades 4 and 5 are all pivotally attached to the shafts 1c and 1d provided on the main base plate 1. However, the shutter blades 4 and 5 are provided with shafts, You may make it the pivotal structure fitted to the hole provided in the main ground plate 1. FIG. Further, the shutter blades 4 and 5 may be pivotally attached to the auxiliary base plate 2.

  A moving magnet type motor (not shown) is attached to the back surface of the main base plate 1, that is, the surface outside the blade chamber. The configuration of this motor is well known in Japanese Patent Application Laid-Open No. 2000-60088. When a stator coil is energized, a rotor having a permanent magnet rotates in a predetermined angle range in a direction corresponding to the energizing direction. It is a motor, Comprising: The rotating shaft of the rotor is a lower right position of the long holes 1b, 2f, and 3d in FIG. The rotor is provided with an output pin that rotates integrally. In the case of this embodiment, the operation pin 6 shown in FIG. 1 is the output pin. Then, the operation pins 6 are sequentially formed in the long hole 1b of the main base plate 1, the long hole 4a of the shutter blade 4, the long hole 3d of the intermediate plate 3, the long hole 5a of the shutter blade 5, and the long hole 2f of the auxiliary base plate 2, respectively. Has been inserted.

  Next, the operation of this embodiment will be described. As described above, the shutter of the present embodiment is a shutter that can be employed for a digital still camera or a silver salt camera. First, the operation when employed in a digital still camera will be described. FIG. 1 shows an initial state in that case. That is, this digital still camera is a normally open type. In this initial state, the power is turned on, and the shutter blades 4 and 5 fully open the exposure opening (opening 1a). Therefore, the solid-state image sensor is exposed to subject light, and the subject image can be observed on a monitor. At this time, the shutter blades 4 and 5 are shaped so that their tip portions do not overlap with each other, and the plane area is reduced.

  When the release button is pressed at the time of shooting, if the camera has an aperture mechanism or an ND filter mechanism, first, based on the measurement result of the subject light, the subject light is reduced or not taken. It is decided whether to shoot. Then, when shooting with a reduced amount of subject light, a diaphragm blade or an ND filter (not shown) is made to enter the exposure opening. Thereafter, when the charge accumulated in the solid-state imaging device is released by a signal from the exposure control circuit, exposure for photographing starts.

  When a predetermined time elapses after the exposure for photographing is started, a positive current is supplied to the stator coil of the motor by a signal from the exposure control circuit. Thereby, the rotor having the rotation shaft at the lower right position of the long hole 1b starts to rotate clockwise. Therefore, the operation pin 6 is moved in the direction of the optical axis from the position shown in FIG. 1, and the closing operation of the shutter blades 4 and 5 is started. FIG. 2 shows a state after the shutter blades 4 and 5 start the closing operation and immediately before the opening of the exposure opening is started, and FIG. It shows the state at the moment of closing.

  As can be seen from FIGS. 2 and 3, the closing of the exposure opening by the shutter blades 4 and 5 starts from both sides of the opening 1a and ends at substantially the center. Therefore, the time from the start of closing of the exposure opening to the end of closing becomes slightly faster than the case of Patent Document 1, and the unevenness of exposure is also improved. Further, the front ends of the shutter blades 4 and 5 overlap before the exposure opening is completely closed, but in the case of this embodiment, the shutter blades 4 and 5 are arranged in separate blade chambers. Even if they are deformed during operation, their tip portions do not collide with each other.

  When the exposure opening is thus closed, the closing operation of the shutter blades 4 and 5 stops with the shutter blade 4 abutting against the stopper 1f. FIG. 4 shows the stopped state. . In this way, in the shutter that rotates the two shutter blades in opposite directions to open and close the exposure opening, it is well known that only one of the shutter blades is brought into contact with the stopper and both of them are suitably stopped. It is. Therefore, although the description thereof is omitted, the shutter blades 4 and 5 may be brought into contact with the stoppers 1f and 1e at the same time.

  In this manner, when the closing operation of the shutter blades 4 and 5 is stopped, the imaging information is transferred to the storage device in that state. When the transfer is completed, the motor stator coil is energized in the opposite direction to that described above. Therefore, the rotor (not shown) is rotated counterclockwise in FIG. 4 and moves the operating pin 6 substantially in the counter-optical axis direction. Thereby, the opening operation of the shutter blades 4 and 5 is started, the exposure opening starts to be opened immediately after the state of FIG. 3, and the opening is finished in the state of FIG. Thereafter, the shutter blades 4 and 5 come into contact with the stoppers 1e and 1f and stop. Immediately thereafter, the energization to the stator coil is cut off, and the initial state shown in FIG. The return operation of the diaphragm blades is returned to the initial position by the driving devices after the shutter blades 4 and 5 are in the state shown in FIG.

  Here, the case where the shutter of the present embodiment is adopted in a silver salt camera will be briefly described. In that case, the state shown in FIG. 4 is the initial state. In the case of a camera equipped with a diaphragm mechanism, the diaphragm blades are operated according to the brightness of the subject light, and then the shutter blades 4 and 5 are opened and closed. Start immediately after 3. Thereafter, when the shutter blades 4 and 5 are stopped in the state shown in FIG. 1, energization in the reverse direction is performed on the stator coil after a predetermined time. Therefore, the shutter blades 4 and 5 start the closing operation, and when the state shown in FIG. 3 is reached, the exposure is finished, and immediately after that, the shutter blades 4 and 5 are stopped and returned to the state shown in FIG.

  In this embodiment, the opening forming edges 4b and 5b of the shutter blades 4 and 5 are formed in an arc shape. However, the shutter blades 4 and 5 have at least one bending point, and the tip end side is fully open from the bending point. In some cases, it may be formed to bend toward the other shutter blade. In this embodiment, the drive source is a moving magnet type motor. However, the drive source of the present invention may be a spring, as described in, for example, Japanese Patent Application Laid-Open No. 2002-62561. Even a step motor can be used. Further, in the case of this embodiment, the operation pin 6 is described as a motor output pin. However, as described in JP-A-2002-62561, the operation pin 6 is reciprocated by a drive source. It may be provided on the member to be provided.

It is the top view of the Example which showed the shutter blade fully open state. It is the top view of the Example which showed the state just before the shutter blade started the closing operation | movement and it started closing an exposure opening. It is the top view of the Example which showed the state of the moment when shutter blade finished closing exposure opening. It is the top view of the Example which showed the state which the shutter blade | wing closed | closed and complete | finished and stopped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main ground plate 1a, 2a, 3a Opening part 1b, 2f, 3d, 4a, 5a Long hole 1c, 1d Axis 1e, 1f Stopper 2 Auxiliary ground plate 2b, 2c, 2d, 2e, 3b, 3c Hole 3 Intermediate plate 4, 5 Shutter blade 4b, 5b Opening edge 6 Actuation pin

Claims (3)

  Two ground plates that are attached to each other with a predetermined interval, an intermediate plate that forms two blade chambers by partitioning the two ground plates, and are separately disposed in the two blade chambers. Two shutter blades pivotally attached to either of the two base plates, each having a long hole and formed so that their tip portions do not overlap each other when the exposure opening is fully opened, A driving means having one operating pin fitted in both of the elongated holes and reciprocating to rotate the two shutter blades in opposite directions; a driving source for reciprocating the driving means; And a camera shutter.   2. The camera shutter according to claim 1, wherein each of the two shutter blades has at least one bending point where each opening forming edge is bent toward the counterpart shutter blade when fully opened. .   3. The camera shutter according to claim 1, wherein the driving source is a motor, the driving means is a rotor of the motor, and the operating pin is an output pin of the motor.