JP4980103B2 - Focal plane shutter for camera - Google Patents

Description

  The present invention relates to a focal plane shutter for a camera having one or two shutter blades.

  In the focal plane shutter for a camera, two blade chambers are formed between three plate members called a shutter base plate, an intermediate plate, and an auxiliary base plate. Two shutter blades, each of which is referred to as `` I '', are arranged separately, and one shutter blade is arranged in the blade chamber formed between the shutter base plate and the auxiliary base plate. It has been. The former focal plane shutter can be adopted for both a silver salt film camera and a digital camera, while the latter focal plane shutter can be adopted only for a digital camera.

  Also, in any focal plane shutter, the configuration of the shutter blades is substantially the same, a plurality of arms having one end in the length direction rotatably attached to the shutter base plate, and at least pivotally supported by these arms. It consists of one blade.

  Further, the shutter blade drive member is rotatably attached to the surface of the shutter base plate outside the blade chamber, and the drive pin extends from the arc-shaped long hole formed in the shutter base plate into the blade chamber. It is fitted in a hole formed in one of the arms. Thereby, when the driving member reciprocates, the shutter blades open and close the exposure opening. The drive member is usually configured to be rotated by the biasing force of the drive spring to one side and to the other by a set member that is rotatably attached to the shutter base plate. Recently, however, it is also known to rotate in both directions by an electromagnetic actuator without using such a drive spring.

  In the focal plane shutter having such a configuration, when there is a large fitting tolerance (hereinafter referred to as rattling) between the hole formed in the arm and the drive pin of the drive member, the operation of the shutter blade is stabilized. I can't get it. For this reason, many proposals have been made to eliminate such rattling, but one configuration enabling this is described in Patent Document 1 below.

JP-A-9-171206

  In the case of the focal plane shutter described in Patent Document 1, the shutter blade is composed of two arms called a main arm and an auxiliary arm and four blades. The main arm has a bifurcated shape like the ten hands used by Edo-era catch officers, and uses the urging force of the bifurcated portion (the elastic portion in Patent Document 1) to sandwich the drive pin. Like to do. However, as is well known, since the arm is made of a thin material, a part of the arm can be bent in a direction perpendicular to the thin plate thickness direction so that elasticity can be obtained. It is actually very difficult to produce.

  The present invention has been made to solve such a problem, and the object of the present invention is to devise the shape of the main arm so that the gap between the hole of the main arm and the drive pin of the drive member. It is an object of the present invention to provide a low-cost and highly feasible focal plane shutter for a camera that can suitably eliminate rattling.

  In order to achieve the above object, the present invention provides a shutter base plate constituting at least one vane chamber with an auxiliary base plate, a plurality of arms including a main arm, and at least pivotally supported by these arms. And at least one shutter blade which is constituted by a single blade, and one end of each of which is rotatably attached to a plurality of blade mounting shafts erected on the shutter base plate, and the shutter base plate And a drive pin that is inserted into the hole of the main arm through the arc-shaped long hole formed in the shaft and is rotatably attached to a surface outside the blade chamber of the shutter base plate, and reciprocally rotates to thereby A focal plane shutter having at least one drive member that causes the shutter blades to open and close, the main arm having the tip at the hole side, The tongue portion is formed so as to be a part of the edge of the plate and is flexible in the thickness direction, and the tongue portion is bent when the drive pin is inserted into the hole. The tip is brought into contact with the drive pin and the edge of the hole on the opposite side of the tip is brought into contact with the drive pin due to its elasticity.

  In this case, if the tip of the tongue is in contact with the drive pin on the opposite side of the direction of movement of the drive pin at the time of shooting, the operation start state of the shutter blade at the time of shooting becomes more stable. In addition, it is advantageous in terms of cost if the tongue is formed so as to be flush with the main arm before the drive pin is inserted.

  The focal plane shutter for a camera according to the present invention has a tongue formed on the main arm so that a tip of the main arm restricts a part of the hole into which the drive pin is inserted, and the drive pin is inserted into the hole. Because it is bent in the thickness direction of the arm, its tip is brought into contact with the drive pin, and the edge of the hole opposite to the tip is also brought into contact with the drive pin due to its elasticity. The arm is very easy to manufacture, which is advantageous in terms of cost, can eliminate the rattling between the hole and the drive pin, and can stabilize the operation of the shutter blades during shooting. There is.

  Embodiments of the present invention will be described with reference to the illustrated examples. The present invention can be applied to a focal plane shutter having two shutter blades and a focal plane shutter having one shutter blade as described above. This is applied to a focal plane shutter having shutter blades. Further, as described above, the focal plane shutter having two shutter blades can be used for both a silver salt film camera and a digital camera, but the embodiment will be described when it is applied to a digital camera. To do.

  The present embodiment will be described with reference to FIGS. FIG. 1 is a plan view of the set state as viewed from the subject side, and FIG. 2 is a plan view of the same set state as viewed from the solid-state image sensor side. FIG. 3 shows the main arm of the leading blade in the same manner as in FIG. 2. FIG. 3 (a) is a plan view, and FIG. FIG. 3C is a sectional view taken along the line A, and FIG. 3C is a sectional view showing the state bent by the drive pin in the same manner as FIG. 3B. 4 is a plan view showing the main arm of the rear blade in the same manner as FIG. Further, FIG. 5 is a plan view showing the state immediately after the exposure operation is finished in the same manner as in FIG. 1, and FIG. 6 is a plan view showing the state at that time in the same manner as in FIG. FIG.

  First, the configuration of the present embodiment will be described mainly with reference to FIGS. The shutter base plate 1 is made of a synthetic resin, and has an opening 1a for a subject optical path in which a rectangular shape is horizontally long at a substantially central portion thereof. On the solid-state image sensor side of the shutter base plate 1, a metal intermediate plate 2 and a synthetic resin auxiliary base plate 3 are attached in order by appropriate means at a predetermined interval, and the shutter base plate 1 and the intermediate plate 2 are attached. Between the intermediate plate 2 and the auxiliary base plate 3, and a rear blade chamber. In FIG. 1, the shutter base plate 1 is shown by partially cutting off the lower right portion so that a part of the intermediate plate 2 and the auxiliary base plate 3 can be seen. The overall shape of the intermediate plate 2 is shown in FIG. Further, the auxiliary base plate 3 is only partially shown in FIG. 1 and does not show the overall shape, but has the same outline as the shutter base plate 1. FIG. 1 shows two hook portions 3 a and 3 b provided on the auxiliary base plate 3 and hung on the subject side edge of the shutter base plate 1.

  As shown in FIG. 2, an opening 2a having a shape slightly larger than the opening 1a is formed at a substantially central portion of the intermediate plate 2 so as to overlap the opening 1a. Although not shown, an opening having a shape slightly larger than the opening 1a is formed at a substantially central portion of the auxiliary ground plate 3 so as to overlap the opening 1a. Therefore, the exposure opening as the shutter unit in this embodiment is regulated by the opening 1 a of the shutter base plate 1.

  In FIG. 1, the shutter base plate 1 has two large elongated holes 1b and 1c each having a substantially arc shape in a region on the left side of the opening 1a, and the planar shape is C-shaped at the lower end thereof. Known buffer members 4 and 5 are attached. As can be seen from FIG. 2, the shape on the right side of the intermediate plate 2 is formed so as to avoid the overlap with the long holes 1b and 1c. Although not shown, the auxiliary base plate 3 made of synthetic resin has substantially the same shape in a region overlapping with the long holes 1b and 1c, but has a long groove that does not penetrate therethrough. .

  As shown in FIG. 1, shafts 1d, 1e, and 1f are erected on the subject side surface of the shutter base plate 1, and the leading blade driving member 6, the trailing blade driving member 7, A set member 8 is rotatably attached. Among them, the leading blade driving member 6 and the trailing blade driving member 7 have driven portions 6a and 7a, mounting portions 6b and 7b, and driving pins 6c and 7c. The blades are biased so as to rotate clockwise by a well-known leading blade driving spring and a trailing blade driving spring not shown. Moreover, the well-known iron piece members 9 and 10 are attached to the attaching portions 6b and 7b. Further, the drive pins 6c and 7c are formed such that the base side is formed as a large diameter portion and the tip side is formed as a small diameter portion, and is inserted into the blade chamber from the long holes 1b and 1c.

  Further, the set member 8 has pushing portions 8a, 8b and a pushed portion 8c, and is biased to rotate counterclockwise by a well-known return spring (not shown). In FIG. 1, a camera-side member (not shown) is in contact with the pushed portion 8c to prevent the counterclockwise rotation. Therefore, when the suppression is released, the set member 8 is rotated counterclockwise, but the rotation is stopped by a stopper (not shown) provided on the shutter base plate 1. ing. FIG. 5 shows the counterclockwise rotation stop position of the set member 8. In the following, the stop position is referred to as the initial position.

  In addition to the above-mentioned shafts 1d, 1e, and 1f, a plurality of shafts (not shown) are erected on the surface of the shutter base plate 1 on the left side of the opening 1a. A well-known support plate (not shown) and a printed wiring board are overlapped and attached so as to be parallel to the shutter base plate 1. A well-known front wing electromagnet and rear wing electromagnet are attached to the support plate attached to the shutter base plate 1 side of the printed wiring board. In FIGS. 1 and 5, those iron cores are used. Only the arrangement state of 11 and 12 is indicated by a two-dot chain line.

  As shown in FIG. 2, shafts 1g and 1h are arranged on the blade chamber side surface of the shutter base plate 1 so as to be concentric with the shafts 1d and 1e provided upright on the subject side surface. In addition to being erected, shafts 1i, 1j, and 1k are erected. Of these shafts, a ring-shaped buffer member 13 is attached around the shaft 1k. Two buffer members 14 and 15 are attached to the outer wall 1 m formed below the shutter base plate 1.

  As described above, the leading blade is disposed in the blade chamber between the shutter base plate 1 and the intermediate plate 2, and the trailing blade is disposed in the blade chamber between the intermediate plate 2 and the auxiliary ground plate 3. First, the configuration of the leading blade will be described. As shown in FIG. 2, the leading blade is composed of two arms 16 and 17 and three blades 18, 19, and 20 that are pivotally supported in the length direction thereof. 16 and 17 are arrange | positioned rather than the blade | wings 18, 19, and 20 at the shutter baseplate 1 side, and those one ends are rotatably attached to said axis | shaft 1g, 1i. Of the two arms 16, 17, the arm 16 is a main arm, the arm 17 is a sub-arm, and of the three blades 18, 19, 20, the blade 20 is a slit forming blade.

  Further, the arm 16 which is the main arm of the leading blade is formed with a hole 16a, into which the driving pin 6c is fitted, and the tip of the hole 16a is formed on the auxiliary base plate 3. It is inserted into an arcuate long groove not shown. Therefore, a specific fitting configuration of the drive pin 6c and the hole 16a will be described with reference to FIG. 3A shows the arm 16 in the same posture as in FIG. 2, but as can be seen from the planar shape of the arm 16, the tip of the arm 16 is a part of the edge of the hole 16a with the tip 16a side. The tongue portion 16b is formed. The tongue portion 16b is formed so as to be flush with the plate surface of the arm 16 as shown in FIG. 3B, but has flexibility, and FIG. As shown in c), when the drive pin 6c is inserted into the hole 16a, it is bent, and its tip is pressed against the drive pin 6c by its elasticity, and the drive pin 6c is pressed against the opposite edge of the hole 16a. ing.

  In this embodiment, the tongue 16b is configured in this manner, but is bent in the insertion direction of the drive pin 6c (downward in FIG. 3 (c)) in FIG. 3 (c). May be bent in the opposite direction (upward in FIG. 3C) in advance, and the drive pin 6c may be inserted there. In the case of the present embodiment, the tongue portion 16b is formed so as to be flush with the plate surface of the arm 16 at the manufacturing stage, as shown in FIG. Bending may be performed at a predetermined angle above or below 3 (b). Furthermore, the arms 16 and 17 of this embodiment need not be made of metal, and may be made of synthetic resin.

  On the other hand, in FIG. 2, the rear blade is composed of two arms 21 and 22 and three blades 23, 24, and 25 that are pivotally supported in the length direction thereof. The arms 21 and 22 are arranged closer to the auxiliary base plate 3 than the blades 23, 24 and 25, and one end of the arms 21 and 22 is attached to the shafts 1h and 1j. It is mounted for rotation. Of the two arms 21 and 22, the arm 21 is a main arm, the arm 22 is a sub-arm, and of the three blades 23, 24, and 25, the blade 25 is a slit forming blade.

  Further, the arm 21 which is the main arm of the rear blade is formed with a hole 21a, into which the drive pin 7c is fitted, and the tip of the hole 21a is formed on the auxiliary base plate 3. It is inserted into an arcuate long groove not shown. As shown in FIG. 4, which is shown in the same posture as FIG. 2, the arm 21 is formed with a tongue 21b whose tip is on the side of the hole 21a so as to restrict a part of the edge of the hole 21a. Yes. However, as can be seen by comparing with FIG. 3 (a), in the case of the tongue portion 16b of the leading blade arm 16, it was formed on the pivot portion side of the blade 18 with respect to the hole 16a. The tongue 21b of the arm 21 of the rear blade is not formed on the pivot portion side of the blade 23 but on the opposite side with respect to the hole 21a. Other than that, the description of the arm 16 with reference to FIG. 3 can also be applied to the arm 21, and the description thereof will be omitted.

  As described above, in the shutter blade of this embodiment, the front blade and the rear blade have one sub-arm not connected to the drive pins 6c and 7c, but two or more sub-arms are also known. ing. In the case of this embodiment, the leading blade and the trailing blade are pivotally supported by three blades. However, it is also known that one blade or two blades other than three are used. It is also known that the number of front and rear blades is different. The shutter blades of the present invention may have any configuration among them.

  Next, the operation of this embodiment will be described. 1 and 2 show a set state, that is, a photographing standby state. At this time, as shown in FIG. 1, the set member 8 is pushed against the urging force of a return spring (not shown) by being pushed by the pushed portion 8 c by a member on the camera body side (not shown). It is rotated clockwise from the initial position to the set position, and the set state is maintained. The leading blade drive member 6 is rotated counterclockwise by the set member 8 against the urging force of a leading blade drive spring (not shown), and the iron piece member 9 is moved to the iron of the leading blade electromagnet. It is in contact with the core 11. The leading blade covers the opening 1a by minimizing the overlapping amount of the three blades 18-20. On the other hand, the rear blade drive member 7 is also rotated counterclockwise by the set member 8 against the urging force of the rear blade drive spring (not shown), and the iron piece member 10 is moved to the rear blade electromagnet. The iron core 12 is contacted. Therefore, the rear blade is stored at a position above the opening 1a with the overlapping amount of the three blades 23 to 25 being maximized.

  When the release button is pressed at the time of photographing, first, the leading blade electromagnet and the trailing blade electromagnetic magnet are energized, so that the iron cores 11 and 12 hold the iron piece members 9 and 10 by suction. Thereafter, the restraining force by a member on the camera body side (not shown) against the pushed portion 8c of the set member 8 is released, and the set member 8 is counterclockwise from the position of FIG. 1 by the biasing force of the return spring (not shown). Rotated in the direction. In the initial stage of the rotation, the pushing parts 8a and 8b of the set member 8 are separated from the pushed parts 6a and 7a of the driving members 6 and 7, but in that stage, each driving member 6 7, since the iron piece members 9, 10 are already held by the iron cores 11, 12 as described above, the exposure operation is not started. Thereafter, when the set member 8 returns to the initial position and stops, energization of the two electromagnets is sequentially cut off at time intervals determined by the exposure control circuit.

  Therefore, when the energization of the leading blade electromagnet is cut off, the attractive force of the iron core 11 with respect to the iron piece member 9 is lost, so the leading blade driving member 6 is biased by a leading blade driving spring (not shown). Is rapidly rotated clockwise. Therefore, the leading blade is exposed by the drive pin 6c, and the three blades 18 to 20 move substantially downward while increasing the overlap between the blades, and open the opening 1a from above. Next, when the power supply to the rear blade electromagnet is cut off, the attracting force of the iron core 12 to the iron piece member 10 is lost, so the rear blade drive member 7 is biased by a rear blade drive spring (not shown). Is rapidly rotated clockwise. Therefore, the rear blade is exposed by the drive pin 7c, and the three blades 23 to 25 move substantially downward while reducing the overlap between the blades, and close the opening 1a from above. Therefore, after that, the imaging surface of the solid-state imaging device is sequentially exposed by the slit formed between the blade 20 of the leading blade and the blade 25 of the trailing blade. Since the edges of the holes 16a and 21a of the arms 16 and 21 are in contact with the drive pins 6c and 7c before and after the operation direction, stable operation can be obtained.

  Thereafter, when the leading blade 20 is completely retracted from the opening 1 a, the driving pin 6 c of the leading blade driving member 6 contacts the buffer member 4, and the leading blade arm 16 contacts the buffer members 13 and 14. Furthermore, when the blades 18 to 20 of the leading blade come into contact with the buffer member 15, the operations of the leading blade drive member 6 and the leading blade are stopped, and the three blades 18 to 20 of the leading blade are opened. It will be in the state stored in the lower position of 1a.

  By the way, in this way, when the drive pin 6c of the leading blade driving member 6 comes into contact with the buffer member 4, the buffer member 4 is deformed by its elasticity and brakes and stops the leading blade drive member 6. However, since the force when the drive pin 6c contacts the buffer member 4 is extremely large, the force of the drive pin 6c is greatly applied to the edge of the hole 16a of the arm 16 at the time of contact. However, in the case of the present embodiment, during the exposure operation, the drive pin 6c pushes the edge of the hole 16a opposite to the tongue 16b, so that the flexible tongue 16 is deformed. As a result, there is almost no risk of rattling between the drive pin 6c and the hole 16a. Therefore, the leading blade is suitably stopped with the bounce suppressed. However, when the tongue portion 16 may be deformed according to the specification, or when it is made difficult to generate rattling by other devices, the position where the tongue portion 16b is formed is changed, and the drive pin 6c is moved during the exposure operation. You may make it push the front-end | tip of the tongue part 16b. The same applies to the case of the arm 21 which is the main arm of the rear blade.

  The exposure operation of the leading blade is completed as described above. However, in the rear blade, immediately after the blade 25 covers the opening 1a, the driving pin 7c of the trailing blade driving member 7 is moved to the buffer member. 5 abuts. Then, when the drive pin 7c comes into contact with the buffer member 5, the rear blade drive member 7 is braked by temporarily compressing the buffer member 5, and the bounce is suppressed as in the case of the leading blade. And stop. 5 and 6 show the end state of the exposure operation in which the opening 1a is closed by the three blades 23 to 25 of the rear blade in this way. In this state, the imaging information is solid. The image is transferred from the image sensor to the storage device.

  When the imaging information is transferred to the storage device, the set operation is performed immediately. In this case, in the state shown in FIG. 5, a member on the camera main body (not shown) pushes the driven portion 8c of the set member 8 to resist the biasing force of the return spring (not shown). Rotate clockwise. As a result, first, the set member 8 has its pushing portion 8a pushing the pushed portion 6a of the leading blade driving member 6 and resists the biasing force of the leading blade driving spring (not shown). The drive member 6 is started to rotate counterclockwise. After that, when the blade 20 for slit formation of the leading blade overlaps with the blade 25 for slit formation of the trailing blade by a predetermined amount, the pushing portion 8b of the set member 8 is pushed by the driving member 7 for the trailing blade. By pushing the portion 7a, the rear blade drive member 7 starts to rotate counterclockwise against the urging force of the rear blade drive spring (not shown). Therefore, after that, the blades 18 to 20 of the leading blade operate upward while reducing the overlap between the blades, and the blades 23 to 25 of the rear blade operate upward while increasing the overlap between the blades. However, at this time, the tongues 16b and 21b of the arms 16 and 21 are not bent at all even if they are pushed by the drive pins 6c and 7c.

  In this way, the set operation is performed, the leading blades 18 to 20 are deployed to cover the opening 1a, and the trailing blades 23 to 25 are overlapped and stored at a position above the opening 1a. In this state, the iron piece members 9 and 10 attached to the drive members 6 and 7 come into contact with the iron cores 11 and 12 of the leading blade electromagnet and the trailing blade electromagnet. Then, when the state is reached, the pushing by the member on the camera body (not shown) stops, and the set state shown in FIG. 1 and FIG. 2 is reached, and this state is waited until the next photographing. Become.

  In the above description, the focal plane shutter according to the present embodiment is used in a digital camera. However, it goes without saying that the present invention can also be used in a camera using a silver salt film. In addition, when employed in a digital camera, there are cases where the shutter base plate 1 is not on the subject side and the auxiliary base plate 3 is on the subject side as in this embodiment. Further, if the leading blade driving member 6, leading blade, and leading blade electromagnet in the present embodiment are not provided, a focal plane shutter for a digital camera having one shutter blade is obtained. And what was comprised in that way is also contained in this invention. Further, the driving members 6 and 7 of the present embodiment are rotated by the biasing force of the driving spring during the exposure operation, but recently, the driving members 6 and 7 do not include the above-described electromagnets and driving springs and are reciprocally rotated by an electromagnetic actuator. Things are also known. The present invention is also applied to such a configuration.

It is the top view of the Example which looked at the set state from the to-be-photographed object side. It is the top view of the Example which looked at the set state from the solid-state image sensor side. FIG. 3 (a) is a plan view showing the main arm of the leading blade in the embodiment in the same manner as FIG. 2, and FIG. 3 (b) is an AA view of FIG. 3 (a). FIG. 3C is a cross-sectional view showing the state bent by the drive pin in the same manner as FIG. 3B. It is the top view which showed the main arm of the rear blade | wing in an Example. It is the top view of the Example which looked at the state immediately after complete | finishing exposure operation similarly to FIG. It is the top view of the Example which looked at the state immediately after complete | finishing exposure operation similarly to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a, 2a Opening part 1b, 1c Long hole 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k Axis 1m Outer wall part 2 Intermediate board 3 Auxiliary base plate 3a, 3b Hook part 4, 5, 13, 14 , 15 Buffer member 6 Lead blade drive member 6a, 7a, 8c Driven portion 6b, 7b Mounting portion 6c, 7c Drive pin 7 Rear blade drive member 8 Set member 8a, 8b Push portion 9, 10 Iron piece member 11 , 12 Iron core 16, 17, 21, 22 Arm 16a, 21a Hole 16b, 21b Tongue 18, 19, 20, 23, 24, 25 Blade

Claims (3)

  The arm includes a shutter base plate that forms at least one blade chamber between the auxiliary base plate, a plurality of arms including a main arm, and at least one blade pivotally supported by the arms. One end of each of the plurality of blade mounting shafts standing on the shutter base plate is rotatably attached to each of the plurality of blade mounting shafts, and the arc-shaped elongated hole formed in the shutter base plate passes through the at least one shutter blade. At least one drive member having a drive pin inserted into the hole of the main arm and rotatably attached to a surface outside the blade chamber of the shutter base plate, and causing the shutter blade to open and close by reciprocating rotation. And the main arm is formed so as to be a part of the edge of the hole with the tip end on the hole side. A tongue portion that is flexible toward the direction, and the tongue portion is bent in a state where the drive pin is inserted into the hole, and the tip thereof is made to move by the elasticity. A focal plane shutter for a camera, wherein an edge of the hole on the opposite side of the tip is in contact with the drive pin.   2. The focal plane shutter for a camera according to claim 1, wherein a tip of the tongue is in contact with the drive pin on a side opposite to a moving direction of the drive pin during photographing.   3. The focal plane shutter for a camera according to claim 1, wherein the tongue is formed so as to be flush with the main arm before the drive pin is inserted. 4.