JP4572207B2 - Aperture device - Google Patents

Description

  The present invention relates to a diaphragm device that switches a diaphragm aperture diameter of a shutter in stages.

  Conventionally, as such a diaphragm device, for example, there is one described in Japanese Utility Model Laid-Open No. 5-79541 by the present applicant. This conventional diaphragm device will be described with reference to FIG.

  In FIG. 8, the rotor 10, the rotor operating lever 11, the throttle operating member 12, and the small throttle plate 73 formed of permanent magnets are rotatably supported on a base plate (not shown) via the rotor shaft 10 a, the shaft 12 a, and the shaft 4. Has been. The small aperture plate 73 is sized to cover the shutter opening 2, has a small diameter aperture opening 73 a, and moves between a first position A covering the shutter opening 2 and a second position B retracting from the opening 2. The shaft 4 is freely supported. Further, the small aperture plate 73 is urged clockwise by a spring 73c, and is in contact with the positioning pin 5 and stopped. In addition, a spring 13 is latched on the diaphragm actuating member 12 and is in contact with the engaging pin 14 and stopped.

When the coil 9 is energized and the stator 9 is excited, the rotor 10 rotates counterclockwise, and the rotor operating lever 11 fixed to the rotor shaft 10a also rotates counterclockwise. This rotation causes the diaphragm operating member 12 to rotate clockwise through the rotor operating lever pin 11 a, and the small diaphragm plate 73 rotates counterclockwise around the shaft 4 through the protrusion 12 b of the diaphragm operating member 12. Then, it moves from the second position B to the first position A, contacts the positioning pin 15 and stops. Accordingly, the shutter opening 2 is regulated by the aperture opening 73a. At this time, the pin 73b fixed to the small diaphragm plate 73 moves the movable iron piece 18 along the attracting surface of the iron core 17a, and when the small diaphragm plate 73 reaches the first position A, the electromagnet 17b is excited and movable. The iron piece 18 is sucked and held, and the small diameter aperture 73a is maintained.
Japanese Utility Model Publication No. 5-79541

  In this conventional diaphragm device, the small diaphragm plate 73 is composed of a single sheet, the size of which covers the shutter opening 2 with a single sheet, and the second film while occupying the first position A. Therefore, the second position B must be sufficiently retracted so as not to cover the shutter opening 2, and therefore a sufficient retreat space for the small aperture plate 73 is required. There is a problem that the area around the area becomes larger.

In order to solve the above-described problems, a diaphragm device according to the present invention includes a fully-open position where two blades are arranged on the outer periphery on one side of a shutter opening and a small diaphragm which covers the shutter opening by moving the two blades in the same direction. Bei give a throttle actuating member which operates on the position, the outer peripheral portion of the two blades is that covered in cooperation with the shutter opening has an arc shape of larger diameter than the circular arc of the shutter opening. For this reason, since it is divided into two blades unlike the conventional diaphragm device, the small diaphragm plate can have a smaller area than the conventional one, and the diaphragm device can be downsized. Further, the two blades may be rotatably supported by the same shaft.

  The small aperture plate can be made smaller than before, and the space around the shutter opening where the small aperture plate retreats from the shutter aperture can be narrowed, and the device can be downsized. In addition, the degree of freedom of the shape and arrangement of parts is improved.

  The diaphragm device according to the present invention is a diaphragm device in which the shutter opening is cooperatively covered with two blades to make a small diaphragm state, and the two blades are arranged on the outer periphery on one side of the shutter opening. It is characterized by comprising a diaphragm operating member that moves to a small diaphragm position that moves the position and two blades in the same direction to cover the shutter opening. Since the two blades cooperate to cover the shutter opening, the small diaphragm plate can be made small, and the periphery of the shutter can be miniaturized.

  Embodiments of the present invention will be described with reference to the drawings. In the description, the same parts as those in the conventional configuration described with reference to FIG.

  In FIG. 1, the stator 9, the rotor 10, and the coil L constitute a swing motor M. The stator 9 is provided with magnetic pole portions 9 a and 9 b, and when the coil L is energized, the N pole and the S pole are respectively provided. appear. Thereby, the rotor 10 can rotate in both forward and reverse directions.

  The sectors 23 and 24 that are driven by the rotation of the swing motor M to open and close the shutter opening 2 are arranged symmetrically with respect to the shutter opening 2 as shown in FIG. 2, and the sector 24 protrudes from a ground plate (not shown). The shaft 25 is supported so as to be rotatable. The sector 23 is supported so as to be rotatable around a shaft 22 protruding from the base plate, and a sector opening / closing lever 20 is supported on the upper surface of the sector 23 so as to be rotatable around the shaft 22. The arm portion 20b of the sector opening / closing lever 20 is engaged with an engaging pin 21 provided on the ground plate, and the sector opening / closing lever pin 20a of the sector opening / closing lever 20 is axially attached to the sector 23 and is engaged with the groove portion 24a of the sector 24. In combination, the sectors 23 and 24 are driven. The sector opening / closing lever 20 is normally urged clockwise by a spring 20d.

  A rotor operating lever 11 is press-fitted and fixed to the rotor shaft 10 a of the rotor 10 shown in FIG. 1, and the rotor operating lever 11 rotates integrally with the rotor 10. A rotor operating lever pin 11a provided in the rotor operating lever 11 is engaged with a throttle operating member 12 supported so as to be rotatable around a shaft 12a projecting from the base plate. The aperture operation member 12 is rotatably abutted through a small aperture plate 3 and a protruding portion 12b, which will be described later, and is always urged counterclockwise by a spring 13.

  Note that the engagement pin 14 is provided on the base plate so that the diaphragm operating member 12 does not rotate counterclockwise when the rotor operating lever 11 rotates clockwise.

  Further, the rotor operating lever pin 11b provided in the rotor operating lever 11 shown in FIG. 2 can come into contact with the sector opening / closing lever 20, and the rotation of the rotor operating lever 11 in the clockwise direction causes the sector opening / closing lever 20 to move counterclockwise. The sector opening / closing lever 20 can operate the sectors 23 and 24 by rotating in the clockwise direction.

  The small aperture plate 3 shown in FIG. 1 has an aperture 3a having a diameter smaller than that of the shutter aperture 2 so that a precise aperture can be quickly regulated and rotated around a shaft 4 protruding from the base plate. Supported as possible. As for the shape of the small aperture plate 3, the outer peripheral shape far from the shutter opening 2 has an arc shape slightly larger in diameter than the arc of the shutter opening 2, but the outer peripheral shape close to the shutter opening 2 is along the arc of the shutter opening 2. It is a concave arc-shaped portion 3d. The pin 3 b erected on the small aperture plate 3 is engaged with the movable iron piece 18. The small aperture plate 3 is normally urged clockwise by a spring 3c, and abuts against a positioning pin 5 projecting from the base plate to keep its position.

  The movable iron piece 18 is attracted to or released from the iron core 17a by ON / OFF of the input signal to the coil 17b of the electromagnet device 17, and when the movable iron piece 18 is released without being attracted to the iron core 17a, The small aperture plate 3 can be moved to the first position A where the opening 3a is in the shutter aperture 2, and the movable iron piece 18 is attracted to the iron core 17a at this position, so that the small aperture plate 3 is in the shutter aperture 2. It cannot be saved from. When the movable iron piece 18 is released from being attracted by the iron core 17a, the movable iron piece 18 can be moved to the second position B in contact with the positioning pin 5 by the spring 3c.

  Since the small aperture plate 3 cannot cover the entire surface of the shutter opening 2 due to the concave arcuate portion 3d at the first position A covering the shutter opening 2, an auxiliary plate 28 for covering this portion is provided. Yes.

  The auxiliary plate 28 is rotatably supported around the shaft 12a. The shape of the auxiliary plate 28 is a shape that can sufficiently cover the shutter opening 2 while slightly overlapping the concave arcuate portion 3d of the small aperture plate 3, and the small aperture plate 3 with the shutter aperture 2 in between. Located on the opposite side. The auxiliary plate 28 is biased counterclockwise around the shaft 12a by a spring 28a. When the diaphragm operating member 12 moves the small diaphragm plate 3 to the first position A via the receiving part 3f by the projecting part 12b, the pin 3e of the small diaphragm plate 3 pushes the projecting part 28b of the auxiliary plate 28. Thus, when the auxiliary plate 28 is made to follow the rotation of the small diaphragm plate 3 and is moved from the second position B illustrated by the solid line to the first position A illustrated by the two-dot chain line, The auxiliary plate 28 can cooperate to cover the entire surface of the shutter opening 2.

  The operation of such an aperture device will be described next. FIGS. 1 and 2 show a state before the shutter is operated. In this state, the electromagnet device 17 is turned off, but the small diaphragm plate 3 is rotated by the urging action in the clockwise direction by the spring 3 c by the positioning pin 5. Since it is regulated, the second position B is maintained.

  Here, as in the case where the subject is bright, the program selection means 1 shown in FIG. 3 selects the first program (shown by a broken line in FIG. 4) that uses only the aperture stop 3a having a smaller diameter than the shutter aperture 2. The case will be described.

  First, when the release button 6 of the camera shown in FIG. 3 is pressed, the control circuit 7 energizes the coil L shown in FIG. By energizing the coil L, first, an S pole is generated in the magnetic pole portion 9a of the stator 9 and an N pole is generated in the magnetic pole portion 9b, and the rotor 10 is rotated counterclockwise. Due to this rotation, the rotor operating lever 11 press-fitted and fixed to the rotor shaft 10a of the rotor 10 also rotates counterclockwise, so that the throttle operating member 12 engaged with the rotor operating lever pin 11a of the rotor operating lever 11 is moved. Accordingly, the small aperture plate 3 also rotates counterclockwise, moves to a position A indicated by a two-dot chain line in FIG. Further, the pin 3e of the small diaphragm plate 3 pushes the protruding portion 28b of the auxiliary plate 28, and the auxiliary plate 28 is moved to the position A indicated by the two-dot chain line in FIG. Due to the action, the shutter opening 2 becomes a small diameter state. In this state, the electromagnet device 17 changes from OFF to ON, and the iron core 17a adsorbs and fixes the movable iron piece 18 to hold the small diaphragm plate 3 and the auxiliary plate 28 in the first position A.

  Next, the coil L is energized in the positive direction, and the rotor 10 and the rotor operating lever 11 start to rotate in the clockwise direction. However, the small aperture plate 3 and the auxiliary plate 28 maintain the state of the first position A because the pin 3b is engaged with the movable iron piece 18.

  When the rotor 10 continues to rotate in the clockwise direction, the rotor operating lever pin 11b provided in the rotor operating lever 11 rotates in the clockwise direction on the sector opening / closing lever 20 that has been stationary until now, as shown in FIG. And the sector opening / closing lever 20 is rotated counterclockwise. Accordingly, the two sectors 23 and 24 rotate in opposite directions via the sector opening / closing lever pin 20a provided in the sector opening / closing lever 20, and exposure is started.

  The sectors 23 and 24 operate for the exposure time determined by the control circuit 7 based on the luminance information, aperture information, film sensitivity ISO information 27, etc. from the photometry unit 26 shown in FIG. Direction energization is performed, and the rotor operating lever 20 is rotated counterclockwise to return to the state shown in FIG.

  Thereafter, the electromagnet device 17 changes from ON to OFF. For this reason, the movable iron piece 18 is released, and the small aperture plate 3 and the auxiliary plate 28 return from the first position A to the second position B by the spring force of the spring 3c, and the operation is completed.

  FIG. 5A shows the above operation as a time chart separately for the sectors 23 and 24, the electromagnet device 17, the small diaphragm plate 3, and the coil L. FIG.

  Next, a case will be described in which a second program (shown by a solid line in FIG. 4) to be used up to the full opening diameter of the shutter opening 2 is selected by the program selection means 1 shown in FIG.

  When the release button 6 of the camera shown in FIG. 3 is pressed, the control circuit 7 energizes the coil L shown in FIG. By this energization, an N pole is generated in the magnetic pole part 9a of the stator 9 and an S pole is generated in the magnetic pole part 9b, and the rotor 10 is rotated in the clockwise direction. As a result, the rotor operating lever pin 11a and the diaphragm operating member 12 do not contact each other, and the diaphragm operating member 12 remains in contact with the engaging pin 14, so that the small diaphragm plate 3 is moved to the second position by the spring force of the spring 13. The standby state is maintained at position B. Further, the electromagnet device 17 remains off.

  The sectors 23 and 24 rotate to the exposure position determined based on the luminance information and the like, and then the coil L is energized in the reverse direction, so that the rotor 10 rotates in the reverse direction (rotates counterclockwise) and returns to the state shown in FIG.

  FIG. 5B shows the above operation as a time chart separately for the sectors 23 and 24, the electromagnet device 17, the small aperture plate 3 and the coil L. FIG.

  In the above description, since the auxiliary plate 28 is positioned on the opposite side of the shutter aperture 2 with respect to the small aperture plate 3, the auxiliary plate 28 opens the shutter aperture 2 from the opposite side of the small aperture plate 3. Although it is the structure which moves to the 1st position A to cover, this invention is set as the structure which moves from the same direction. This example will be described next with reference to FIGS.

  First, in the example of FIG. 6, a small diaphragm plate 33 having a small-diameter diaphragm opening 33 a and an auxiliary plate 38 on the outer periphery on one side (right side) of the shutter opening 2 are both pivoted by the same shaft 34. The small diaphragm plate 33 is urged clockwise by a spring 3c. The projecting portion 12b of the diaphragm operating member 12 first contacts and presses the receiving portion 38f of the auxiliary plate 38, then contacts the receiving portion 33f of the small aperture plate 33, and thereafter presses both at the same time to indicate the two-dot chain line. 1 is moved to position A. The other components having the same configuration as in FIG. 1 are denoted by the same reference numerals, and the operation is the same.

  In the example of FIG. 7, a small diaphragm plate 43 having a small-diameter diaphragm opening 43 a and an auxiliary plate 48 on the outer periphery on one side (right side) of the shutter opening 2 are both pivotally supported by the same shaft 44. The small diaphragm plate 43 is urged clockwise by the spring 3c. The shape of the small aperture plate 43 is an outer peripheral portion 43d in which the outer peripheral portion close to the shutter opening 2 has an arc shape slightly larger than the arc of the shutter opening 2 and the outer peripheral portion far from the shutter opening 2 is cut out. Yes. The auxiliary plate 48 has a substantially arcuate shape and covers the shutter opening 2 in cooperation with the outer peripheral portion 43d. Accordingly, the projecting portion 12b of the diaphragm actuating member 12 first contacts and pushes the receiving portion 43f of the small diaphragm plate 43, touches the receiving portion 48f of the auxiliary plate 48 with a slight delay, and thereafter presses both at the same time to indicate the two-dot chain line. To the first position A shown in FIG. The other components having the same configuration as in FIG. 1 are denoted by the same reference numerals, and the operation is the same.

  In the above-described embodiment, the diaphragm operating member is operated by a motor. However, the present invention is not limited to this and may be manually operated. In addition, the diaphragm device of the present invention can be used for a video camera as well as a photographic camera using a film or a charge coupled device.

It is a front view which shows the initial state before the shutter operation | movement which applied the aperture device. It is a front view of the sector and its related member in the initial state before shutter operation same as the above. It is a control block diagram of the diaphragm | throttle device shown in FIG. 1, FIG. It is an Ev value diagram showing the first program and the second program. (A) is a time chart which shows operation | movement of each member at the time of selecting a 1st program, (b) is a time chart which shows operation | movement of each member at the time of selecting a 2nd program. It is a front view which shows the initial state before the shutter operation | movement which applied the aperture_diaphragm | restriction apparatus which shows one Embodiment of this invention. It is a front view which shows the initial state before the shutter operation | movement which applied the aperture_diaphragm | restriction apparatus which shows other embodiment. It is a front view which shows the initial state before the shutter action | operation in the conventional apparatus.

Explanation of symbols

2 Shutter opening 3, 33, 43 Small aperture plate 3a, 33a, 43a Aperture aperture 12 Aperture operation member 28, 38, 48 Auxiliary plate A 1st position B 2nd position

Claims (2)

In a diaphragm device that covers a shutter opening with two blades in a cooperative manner to achieve a small diaphragm state,
E Bei diaphragm actuating member for operating the two blades and a fully open position to place the two blades on the outer circumference of one side of the shutter opening to the small aperture position covering said shutter opening by moving in the same direction ,
2. A diaphragm apparatus according to claim 1, wherein the outer peripheral portions of the two blades have an arc shape larger in diameter than the arc of the shutter opening and cooperatively cover the shutter opening .   2. The diaphragm device according to claim 1, wherein the two blades are rotatably supported by the same shaft.