JPS6237217Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of a synchronization mechanism in a camera shutter.

<Prior art> Several types of synchronization mechanisms have been devised in the past, but the recent trend has been to use flash devices (e.g. strobe devices, etc.) as cameras become more compact.
have also become smaller, and due to the characteristics of the discharge tube, the trigger voltage of the synchro contact has become lower than before. Therefore, it is necessary to keep the contact resistance of the synchronizing contact low, and for this reason, the synchronizing contact that has the lowest contact resistance and is simple to contact is the one that has two contact pieces that make contact. Ta.

In this case, the timing of the synchronizing contact should preferably be taken from the iron piece member, which is the member that is displaced from the pressure contact position to the separation position when the electromagnet for exposure control is turned off, so-called "leaf type". ” Most of the synchro tuning devices are
Contact is made by a member, ie, an iron piece member, which is displaced from a position in which it is pressed against the electromagnet to a position in which it is separated from the electromagnet when the electromagnet is turned off.

<Problems to be solved by the invention> However, once the conventional iron piece member is displaced from the position where it presses against the electromagnet to the position where it is separated from the electromagnet when the electromagnet is turned off, it remains displaced until the next time the shutter is set to charge. The synchronizing contact remains in the released position (i.e., the separated position), and therefore the synchronizing contact remains on.As a means to avoid this, conventionally, for example, the synchronizing contact is connected in series with the switch that is switched by the release member. The synchro circuit is turned off when the shutter is set, which increases the number of components and increases the contact resistance, which can lead to problems with reliability, such as when the flash device erroneously fires when the shutter is set. It also had the disadvantage of being extremely inferior in terms of gender.

The present invention was developed in view of the above-mentioned drawbacks, and the opening and closing of the only synchro switch is controlled only when the shutter is closed, thereby preventing the flash device from firing erroneously when the shutter is set. It is an object of the present invention to provide a synchronization mechanism that is mechanically simpler and has improved reliability by preventing such occurrences.

<Means for Solving the Problems> The above-mentioned object of the present invention is to provide an electromagnet, an iron piece member having a tendency to separate from the electromagnet, and a release member that locks the iron piece member at a pressure contact position with respect to the electromagnet. and a locking member that is given an operating habit of engaging the iron piece member in the opposite direction, and the locking member at a position corresponding to the state of pressure contact of the iron piece member with the electromagnet in a tensioned state. The lock is released and moves due to the displacement of the locking member accompanying the separation movement of the iron piece member, and as a result of the movement, the iron piece member is connected to the electromagnet that can be locked by the release member. The shutter mechanism is set by a shutter blade closing drive member that returns the shutter blade to the pressure contact position, and a synchro switch that is closed by the movement of the iron piece member away from the electromagnet and opened by the return movement of the iron piece member. At times,
This is achieved by a synchronization mechanism in a camera shutter configured such that the iron piece member is held in a pressure contact position with respect to the electromagnet by the release member so as not to be displaced in a manner that would close the synchronization switch. .

<Operation> In the above configuration, the electromagnet is excited at the beginning of the release operation, and the iron piece member is attracted and held by the electromagnet. Then, by displacing the release member by the release operation, for example, the charged opening/closing lever is unlocked and the shutter blade is opened, and the electromagnet is then demagnetized at the appropriate timing to release the iron piece caused by the electromagnet. Release the adsorption of parts. At this time, the locking of the iron piece member to the pressure contact position by the release member is also released, so the iron piece member separates from the electromagnet, and the locking of the closing drive member is caused by the displacement of the locking member accompanying this separation movement. is released and the synchro switch is closed. Then, by the movement of the unlocked closing drive member, the shutter blade is closed, for example, via the opening/closing lever, and the iron member is returned to the position where it is pressed against the electromagnet, where it can be locked by the release member. and close the synchro switch. Thereafter, when the release member returns to its initial position, the iron piece member is maintained in its pressed position against the electromagnet, and will not be displaced during the setting operation to close the synchro switch.

<Example> The present invention will be explained below with reference to the example shown in FIGS. 1 to 3.

Reference numeral 1 denotes a shutter base plate, which has an aperture 1a, a light receiving window 1b, escape holes 1c, 1d, and bends 1e, 1f, and has pins 1g to 1j planted therein. 2, 3, and 4 are pins and shafts implanted on other fixing members (not shown).

Reference numeral 5 designates a main release plate, which is formed with an arm portion 5a, a bending portion 5b, and long grooves 5c, 5d, and is arranged to be movable up and down by the fitting relationship between the long grooves 5c, 5d, the pin 2, and the shaft 4. The strong spring 6 also gives it the ability to move upward.

7 is an auxiliary release plate, which includes a bending 7a restrained by the arm 5a, other bending 7b, 7c, and arm 7d, 7e.
and long grooves 7f, 7g are formed, and a pin 7h is planted, and the long grooves 7f, 7g and pins 1g, 1
It is arranged to be movable up and down by the fitting relationship of h, and is given the tendency to move downward by a spring 8.

9 is a signal board with a bend 9a that can restrain the arm 7e.
A stepped portion 9b and long grooves 9c and 9d are formed, and the long grooves 9c and 9d are arranged so as to be movable left and right by the fitting relationship between the pin 3 and the shaft 4, and a spring 10 gives a leftward movement habit. . Reference numeral 11 denotes a signal release lever, which has a bent 11a that engages with the stepped portion 9b and a bent 5b.
The arm portion 11b is pivotably connected to the shaft 4, and is provided with left rotation by a spring 12.

Reference numeral 13 denotes a release lever, which includes an arm portion 13a that can be pushed by the arm portion 7d, a hook 13b, and a circular arc surface 13c.
It is pivotally connected to a shaft 14, and is given levorotation by a spring 15.

Reference numeral 16 denotes a control lever, which has an arm 16a that engages with the hook 13b, an arm 16b that can come into contact with the shaft 14, another arm 16c, and a bend 16d. Support shaft 16
f is implanted, and is pivotally connected to a shaft 17, and a spring 18 provides dextrorotation, and a spring 19 provides levorotation. 20 is an iron piece lever,
Back surface 20 that can be restrained by hook 20a and pin 7h
b, forming a slope 20c and a bending 20d, and supporting shaft 1
6f, and is given dextrorotation by a spring 21. 22 is a piece of iron bent 20d
, and is pressed downward by a spring 23. The iron piece 22 is in contact with the magnetic pole of an electromagnet (not shown) located below in the state shown in FIG.

24 is a hold lever, which forms a bend 24b with an arm 24a that engages with the pin 16e, is pivotally connected to the shaft 17, and is given dextrorotation by a spring 25 tensioned between it and the control lever 16. ing.

Reference numeral 26 designates a set plate, which has a step portion 26a that engages with the bend 24b, a bend 26b that can engage with the arm portion 16a, a side surface 26c, and long grooves 26d, 26e. It is arranged so that it can be moved left and right due to the fitting relationship, and
Spring 19, 18 provides leftward movement behavior.

Reference numeral 27 denotes an opening/closing lever, which has a stepped portion 27a that engages with the hook 13b of the release lever 13 and an arcuate surface 13c.
A pin 27d that can be pushed by the side surface 26c of the set plate 26 and a pin 27d that passes through the relief holes 1c and 1d of the shutter base plate 1 are formed. Pins 27e and 27f protruding from the back side are implanted and are pivotally connected to a shaft 28, and a spring 29 provides left rotation.

30 and 31 are shutter blades that also serve as aperture blades arranged on the back side of the shutter base plate 1, and pin 27
Long grooves 30a and 31a are formed into which the shafts 30a and 27f fit, and are pivotally connected to a shaft 32 on the back side of the shutter base plate 1 at the same position as the shaft 17. Note that one shutter blade 30 has a warning window 30b for exposure warning facing the light receiving window 1b and a light receiving aperture edge 30 for controlling exposure.
It forms c.

32 is a contact piece attached to the sub-release plate 7;
Conductive pattern 33 arranged on shutter base plate 1
- 36 constitute a power switch and a trigger switch. Note that the contact points for each pattern of each leg of the contact piece 32 are at the positions shown by the dashed-dotted lines.

A synchro switch 37 is supported on the shutter base plate 1 and is operated by bending 16d of the control lever 16.

1 and 2 show the shutter control mechanism section and the shutter blade opening/closing mechanism section separately in order to avoid complication of the drawings, and the opening/closing lever 2 is shown separately.
7 is located below the set plate 26.

Next, the operation will be explained.

First, in the set state shown in FIGS. 1 and 2, when the main release plate is pushed down against the tension of the spring 6 (a force obtained by subtracting the tension of the spring 8), the arm portion 5a
The sub-release plate 7 is bent so that the bending 7a follows the displacement of
is lowered by the tension of the spring 8, and the contact piece 32 is separated from the pattern 33 and comes into contact with the pattern 34. That is, the power switch is turned on.

When the power switch is turned on, a shutter drive control circuit (not shown) is activated, and after checking the power supply voltage (battery voltage), if the power supply voltage is higher than a predetermined value, the electromagnet is excited. The iron piece 22 is attracted and held until the timing described later. On the other hand, if the power supply voltage is below a predetermined value, power to the electromagnet is instantaneously cut off.

The above operation is performed when the sub-release plate 7 is lowered and the contact piece 32 is separated from the pattern 33 and comes into contact with the pattern 34.

When the main release plate 5 is further pushed down, the arm portion 7e of the sub-release plate 7 first comes into contact with the bend 9a of the signal plate 9 (this point is hereinafter referred to as the first locking).

Here, the force of spring 6 is W ₁ and the force of spring 8 is
If W ₂ is assumed, the charge force pushing down the main release plate 5 should have been greater than W ₁ - W ₂ before the first locking, but after the first locking, it should have been larger than W ₁ . Therefore, the operator can know the transition from the battery check and camera shake warning operation stroke stage to the shutter release operation stroke stage by the change in the required charge force. If pressing down of the main release plate 5 is stopped at the first locking stage, the tension of the spring 6 causes the main release plate 5 and the sub-release plate 7 to return to the state shown in FIG. Note that, up to the first locking point, members other than the release plates 5 and 7 are not displaced.

Now, when the main release plate 5 is further pushed down from the first locking stage, the bend 5b contacts the arm 11b and turns the signal release lever 11 to the right against the tension of the spring 12. It comes off from 9b. Therefore, the signal plate 9 moves to the left by the tension of the spring 10, and the restraint of the arm portion 7e by the bending 9a is released.

As a result, the sub-release plate 7 is further lowered by the tension of the spring 8.

Here, first, when the power supply voltage is below the specified value, the iron piece 2
The operation when no adsorption force is generated in the electromagnet (not shown) disposed below 2 will be described.

When the bending 7b comes off the hook 20a due to the lowering of the sub-release plate 7, the iron piece lever 20 is moved to the support shaft 16f since the iron piece 22 is not attracted to the electromagnet.
The hook 20a rotates to the right by the tension of the spring 21 using the fulcrum as a fulcrum, and the hook 20a enters the locus of movement of the bend 7c.

Therefore, the bending 7c of the sub-release plate 7 is restrained by the hook 20a of the iron piece lever 20, so that
Its descent is prevented. As a result, the shutter release is not performed and the release is prevented.

If pressing down of the main release plate 5 is stopped in this state, everything except the signal plate 7 returns to the state shown in FIG. 1. The iron piece lever 20 is rotated to the left against the tension of the spring 21 by pushing the slope 20c toward the bending 7b when the sub-release plate 7 returns upward, and presses the iron piece 22 against the electromagnet. Also, the hook 20a is retracted from the locus of movement of the bend 7c and is restrained by the side surface of the bend 7b as shown.

Note that the release prevention mechanism of the embodiment prevents the sub-release plate 7 from lowering, but when the force of the spring 8 is large and the lowering speed of the release plate 7 is fast, the iron piece lever 20 cannot be rotated to the right. Sub-release plate 7
There may be cases where the shutter release cannot be prevented in time because of the lowering of the shutter. To counter this, the portion of the signal plate 9 extending to the right of the bend 9a may be lengthened downward to the right or bent in a step-like manner as shown in FIG. should be made slower.

Next, an explanation will be given of the operation when the power supply voltage is higher than a specified value and an attractive force is generated in the electromagnet.

During the above-described lowering process of the sub-release plate 7, the iron piece 22 is attracted and held by the electromagnet, and the iron piece lever 20
Since the release plate 7 does not rotate to the right, the release plate 7 descends to the final stroke, and the arm 7d pushes the arm 13a to rotate the release lever 13 to the right against the tension of the spring 15, and the hook 13b moves to the step. 27a and arm portion 16a.

Therefore, the opening/closing lever 27 is rotated to the left by the tension of the spring 29, and the pin 27e, the long groove 30a, and the pin 2
7f and the long groove 31a, the shutter blades 30 and 31 are rotated in different directions about the shaft 32 as a fulcrum.

A warning window 30b and a light-receiving aperture edge 30c are formed on the shutter blade 30, and as the shutter blade 30 rotates, the warning window 30b is first retracted from the light-receiving window 1b, and a known photodiode for photometry is temporarily placed in the field of view. The photodiode is shielded from light and then exposed to field light again by an aperture that gradually becomes larger due to the cooperation of the light receiving window 1b and the light receiving aperture edge 30c. Further, the aperture 1a is opened with a delay of about a mechanical delay time relative to the light receiving section side by the shutter blades 30 and 31, and is finally fully opened.

Here, it is assumed that the operating torque of the control lever 16 is set as follows.

The force of the spring 19 is W ₃ , the force of the spring 18 is W ₄ , the distance from the shaft 17 of the control lever 16 to the self-latching position of the spring 19 is Ra, and from the shaft 17 to the self-latching position of the spring 18 ( If the distance to the pin 16e) is Rb, the control lever 16 is _W3・Ra−
A left turning force is applied with a torque of W ₄・Rb (however, W ₃・Ra > W ₄・Rb).

Therefore, the control lever 16, which is unlocked by turning the release lever 13 to the right, moves to the above-mentioned _W3.Ra-
Attempt to turn left with torque of W ₄・Rb. but,
Since the iron piece 22 is attracted and held by the electromagnet, the control lever 16 cannot be rotated to the left.

On the other hand, as the sub-release plate 7 descends to its final stroke, the contact piece 32 comes into contact with the pattern 35, thereby closing the trigger switch.

As a result, the shutter drive control circuit (not shown) starts a photometry operation, and after a suitable time elapses, the power to the electromagnet (not shown) is cut off to demagnetize it. When the attraction force of the electromagnet is lost, the iron piece 22 is released, and the control lever 16 _is moved as described above.
It rotates to the left with the torque of W ₄ · Rb, and at the same time pushes the arm 24a with the pin 16e to rotate the hold lever 24 to the left to remove the bending 24b from the step 26a of the set plate 26, and the self is synchronized by the bending 16d. Switch 37 is closed. Therefore, when the flash device is set to a usable state, light is emitted.

Further, the set plate 26 which has been released from the lock moves to the right due to the tension of the spring 19, and first the side surface 26c
comes into contact with the pin 27d and the opening/closing lever 27 is moved by the spring 2.
9 to the right to close the shutter blades 30 and 31 which have fully opened the aperture 1a or are in the middle of opening the aperture 1a.

Also, in the process of moving the set plate 26 to the right,
Since the spring 19 becomes ineffective from the time when the bending 26b comes into contact with the arm portion 16a of the control lever 16, from then on, the torque of W ₄ ·Rb by the spring 18 is used to
The control lever 16 is rotated to the right until the arm 16b abuts the shaft 14, and the set plate 26 is moved to the right.

By returning the control lever 16 to the right, the bending 1
Since the operation of the synchro switch 37 by 6d is released, the switch 37 is opened. Since the open state of the synchro switch 37 is maintained until the next opening/closing operation, the flash device will not cause the flash device to erroneously emit light.

Here, when the main release plate 5 is released from being pressed down, the main release plate 5 returns upward due to the tension of the spring 6, and from the middle, the arm portion 5a engages with the bending portion 7a, and resists the tension of the spring 8 to release the main release plate 5. Return the release plate 7 upward. As a result, the contact piece 32 first moves away from the pattern 35 to close the trigger switch, and then moves away from the pattern 34 to close the power switch.

Further, the release lever 13 is connected to the sub-release plate 7.
Retraction of arm portion 7d and opening/closing lever 27 due to return of
When the lever returns to the right and the circumference 27d retreats from the arcuate surface 13c, the lever rotates to the left due to the tension of the spring 15 and returns to a state in which the control lever 16 and the opening/closing lever 27 can be locked. In the returned state of the sub-release plate 7, the iron piece lever 20 is held by the sub-release plate 7 against the spring 21 at a position in which it is pressed into contact with the electromagnet shown in the first figure.

Now, if the main release plate 5 is released before the shutter closing signal is generated in the electromagnet, that is, before the opening/closing lever 27 returns to the right rotation, the main release plate 5 and the sub-release plate 7 are Return as described above. However, the release lever 13
The left rotation is temporarily inhibited by the arcuate surface 13c coming into contact with the circumferential surface 27b of the opening/closing lever 27,
The power switch is opened by the return of the sub-release plate 7, and the state is the same as when a closing signal is generated in the electromagnet, and the closing operation as described above is performed, and the peripheral surface 2
7b retreats from the arcuate surface 13c, it further rotates to the left and returns to the state in which the control lever 16 and the opening/closing lever 27 can be engaged. Although this operation does not result in proper exposure control, it does not cause the shutter blade to remain open or interfere with subsequent photographing.

Also, the signal plate 9 and the set plate 26 are moved to the right and left, respectively, by the shutter setting operation, and the stepped portion 9b is bent 11a of the signal release lever 11.
If the step 26a is again engaged with the bend 24b of the hold lever 24, everything returns to the set state shown. During this setting operation, since the iron piece lever 20 is held in the position where it is pressed against the electromagnet by the sub-release plate 7, it will not be displaced to the separation position and close the synchro switch 37.

In the above embodiment, when the battery voltage is below the specified value, the shutter release operation is mechanically blocked as described above, and the closing operation is not performed at this time. set)
Since it cannot be operated, this becomes a signal indicating that the battery voltage is below the specified value, prompting the battery to be replaced.

<Effects> As described above, the synchronizing mechanism in the camera shutter of the present invention is such that the opening and closing of the only synchronizing switch is controlled only when the shutter is closed, so that it can be closed when the shutter is set, etc. It has the characteristics of being an extremely reliable synchronization mechanism for camera shutters that can reliably prevent the flash device from firing erroneously, and is also functionally simpler. It is valid.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of one embodiment of a shutter mechanism for a camera to which the present invention is applied, and FIG. 3 is a partial explanatory diagram of another embodiment of the shutter mechanism. 1... Shitsuyata base plate, 1a... Aperture, 1
b... Light receiving window, 5... Main release plate, 7... Sub-release plate, 9... Signal board, 11... Signal release lever, 13... Release lever, 16... Control lever, 20... Iron piece lever , 22... Iron piece, 24...
...Hold lever, 26...Set plate, 27...
Opening/closing lever, 30, 31... Shutter blade that also serves as aperture blade, 30b... Warning window, 30c... Light-receiving aperture edge, 32... Contact piece, 33-36... Conductive pattern, 37... Synchro switch.

Claims (1)

[Scope of Claim for Utility Model Registration] An electromagnet, an iron piece member that has a tendency to separate from the electromagnet, a release member that locks the iron piece member at a pressure contact position with respect to the electromagnet, and the iron piece member, A locking member having an actuation habit of engaging in the opposite direction of separation, and a locking member at a position corresponding to the state of pressure contact of the iron piece member with the electromagnet are locked in a tension state, and the iron piece member is separated. The shutter blade is released from its lock due to the displacement of the locking member due to the movement, and moves and returns the iron piece member to a position in pressure contact with the electromagnet where it can be locked by the release member. a synchro switch that is closed by the movement of the iron piece member away from the electromagnet and opened by the return movement of the iron piece member; A synchronizing mechanism for a camera shutter, characterized in that the iron piece member, which is locked in a position where it is pressed into contact with the electromagnet, is prevented from being displaced in a manner that would close the synchronizing switch.