JP2767452B2 - camera - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a camera having a plurality of electromagnetic driving devices driven by a common power supply.

[Background of the Invention]

Many devices for driving a camera shutter by electromagnetic force have been proposed. These shutter devices not only simplify the drive mechanism of the shutter, but also do not require a charging operation, as compared with a conventional shutter device that is charged by obtaining a driving force from another mechanism such as a film winding mechanism. The mechanism of the whole camera is also simplified.

For this reason, the electromagnetically driven shutter device tends to be widely used from high-end machines to popular-type compact cameras.

FIG. 6 shows an example of a monostable high-speed control solenoid used as an actuator of such a shutter device, and its configuration is such that a permanent magnet 30D, a coil 30C adjacent thereto and a bobbin of the coil 30C can swing. The movable iron core 30A is provided with a movable member 30B attached to the tip of the movable iron core 30A.

When power is not supplied to coil 30C, movable iron core 3
0A is attracted to the permanent magnet 30D, and the movable member 30B is
When the coil 30C is energized, its electromagnetic force acts in the same direction as the attraction force of the permanent magnet 30D depending on the direction of the current, and when it acts in the direction to cancel the attraction force of the permanent magnet 30D. There is. In the latter case, when the energizing current exceeds a certain level, a driving force exceeding the attraction force of the permanent magnet 30D is generated, and the movable member 30B rotates counterclockwise around the support shaft 30F and moves to the first position shown in the drawing. The second illustrated opposite
To the position.

Next, when the current supply to the coil 30C is stopped, the movable member 30B returns to the first position again. In the following, the description will be limited to the case where current is supplied so that the electromagnetic force of the coil 30C acts in a direction to cancel the attractive force of the permanent magnet 30D.

Therefore, by energizing the coil 30C by means such as fitting the drive pin 30E protruding from the movable member 30B into the long hole of the shutter blade, the shutter blade can be opened and closed, and the exposure amount at that time is It can be seen that it becomes variable depending on the current supply time to the coil 30C.

Cameras having such an electromagnetically driven shutter device often include a plurality of electromagnetic drive devices in addition to the shutter device, and some of them operate at the same time as the shutter blades. In addition, these electromagnetic drive devices often commonly use a battery built into the camera as a power source.

[Problems to be solved by the invention]

Cameras are intended to be small and light, and all devices in the camera are required to be small. here,
For example, when the size of the electromagnetic driving device is reduced, the amount of operating force is insufficient, so that a relatively large current is required, and the power supply capacity is insufficient, which may cause a problem in stable operation.

In the camera, as a power supply driving device that operates simultaneously, for example, a shutter driving device, a lens feeding device that feeds a photographing lens a predetermined amount and holds it at a focus position, or a shutter driving device, There is a combination of an aperture driving device or the like that holds the position, and in some cases, it is necessary to simultaneously operate two or more types of electromagnetic driving devices.

Attempting to operate two or more electromagnetic drive devices simultaneously in this manner may cause an accident that one of the electromagnetic drive devices, for example, the shutter drive device does not operate and the shutter does not open depending on the power supply capacity. In addition, one electromagnetic driving device, for example, a lens extension device is operated or not operated depending on photographing conditions, so that the voltage applied to the shutter driving device changes even if the power supply is constant.

The present invention has been made to solve these problems. In a camera having an electromagnetic shutter mechanism operated by a plurality of electromagnetic driving devices driven by a common power supply, the aperture diameter is changed by a very simple mechanism configuration. In addition to providing a camera that performs a two-stage shutter operation,
It is an object of the present invention to provide a camera in which a limited power supply capacity is skillfully used, and a fluctuation of a load on a power supply is eliminated so that an electromagnetic driving device operates stably.

[Means for solving the problem]

The object is to provide a second electromagnetic drive device that opens and closes shutter blades via a movable member, an operating member having a function of preventing the movement of the movable member in the middle, A first electromagnetic driving device that regulates the first and second electromagnetic driving devices to a second position, wherein the control unit controls driving of the first and second electromagnetic driving devices, and the first electromagnetic driving device controls the operating member to the first position;
When the movable member is restricted to the position, the movement of the movable member is prevented halfway, the shutter blade is half-opened by the driving of the second electromagnetic driving device, and the operating member is moved to the second position by the first electromagnetic driving device. When the movement is restricted, the movement of the movable member is not limited. This is achieved by a camera having an electromagnetic shutter mechanism that performs a full-opening operation of the shutter blades by driving the second electromagnetic driving device.

In the above invention, the first and second electromagnetic driving devices are driven by a common power supply, and the first electromagnetic driving device is configured to move the operating member from the first position to the second position. 1 and the first current are smaller than the first current and the operating member cannot be moved from the first position to the second position. However, after the operating member moves to the second position, In a preferred embodiment, the second electromagnetic drive device is driven by a second current that can be held at two positions, and the second electromagnetic drive device is driven in a state where a second current is supplied to the first electromagnetic drive device. is there.

〔Example〕

 One embodiment of the present invention is shown in FIGS.

FIG. 1 omits the shutter blades and the shutter blade holding plate. See FIG. 2 for these.

FIG. 1 shows two electromagnetic driving members attached to the outer portion of the camera shutter device of the present invention.
Is a shutter base plate that constitutes a shutter device, 20A is an opening for an optical path for photography, 30 is a monostable high-speed control solenoid that is an actuator for driving shutter blades, and the monostable high-speed control solenoid 30 is the shutter base plate 20. On the other hand, the hook member 20B is elastically engaged with the pair of upper and lower hook members 20B projecting therefrom and fixedly held.

30C in the monostable high-speed control solenoid 30 is:
A coil for obtaining a driving force by energization, 30A is a movable iron core swingably supported in a bobbin of the coil 30C, 30B is a movable member provided at the tip of the movable iron core 30A,
Further, reference numeral 30D is a permanent magnet serving as a biasing means for the movable iron core 30A.

The monostable high-speed control solenoid 30 corresponds to the second electromagnetic driving means in the present invention.

On the other hand, reference numeral 40 denotes a regulating member for preventing the movement of the movable member 30B in the middle, and the movable member 3 is provided by energizing the coil 30C.
This serves to prevent OB from moving from the first position to the second position on the way.

The regulating member 40 is axially mounted on the shutter base plate 20 and is constantly urged clockwise by a return spring 43. The urged regulating member transmits an urging force to the movable iron core 50B of the plunger solenoid 50 of the regulating member driving actuator, and the urged movable iron core 50B is engaged with the stopper 44.

40A and 40B are bent portions formed on the regulating member 40, the bent portion 40A engages with the movable iron core 50B to transmit the urging force, and the bent portion 40B
0 is a target to which the movable member 30B collides when the movement of the movable member 30B is prevented.

Note that the regulating member 40 corresponds to an operating member according to the present invention.

On the other hand, the energization of the plunger solenoid 50 is controlled by the control unit, but when the energization is not performed or when the second current referred to in the present invention is supplied, the movable iron core 50B Direction, and is locked at that position by a stopper 44 to hold the regulating member 40 at the position shown.

When the first current referred to in the present invention is supplied to the plunger solenoid 50, the movable iron core 50B is attracted and moves leftward, and the regulating member 40 retreats from the movement locus of the movable iron core 30B. Even if 30A swings, the movable member 30B does not collide with the bent portion 40B. In addition, the movable iron core 5
Even if the current supplied to the plunger solenoid 50A is switched to the second current according to the present invention after 0B moves to the left, the movable iron core 50B is held while moving to the left.

In addition, the plunger solenoid 50 is the first type in the present invention.
The position of the regulating member 40 shown in FIG. 1 corresponds to the first position of the operating member according to the present invention. The second position of the operating member according to the present invention refers to a position where the regulating member 40 retreats from the movement locus of the movable member 30B and the bent portion 40B does not collide with the movable member 30B.

Reference numeral 23 denotes a pair of left-right symmetrical shutter blades housed in a slit-shaped space formed between the shutter blade holding plate 21 fixed to the shutter base plate 20 by screws and the shutter base plate 20, Reference numeral 24 denotes a curved portion provided to determine the opening area of the shutter blade 23 in accordance with the rotation angle. The shutter blade 23 is provided on the shutter base plate 20.
An elongated hole 26 that fits by inserting a shaft 25 that is fitted into the hole and serves as a fulcrum of its rotation and a drive pin 30E protruding from the movable member 30B.
And each is provided. In addition, the shutter base plate 20 includes
An elongated hole 20C is provided so that the drive pin 30E protruding from the movable member 30B can be moved by the swing of the movable iron core 30A.

When power is not supplied to the coil 30C of the monostable high-speed control solenoid 30 by the control unit, that is, in a state before the exposure operation, the movable member 30A is
The shutter blade 23 is biased and held at the stable first position by the suction force of 0D, and keeps the shutter blade 23 at the closed position.

In normal shooting, when the subject has high brightness, the control unit supplies only the second current to the plunger solenoid 50, so that the regulating member 40 is set at the position shown in FIG. When the movable member 30B attempts to move, the movable member 30B collides with the bent portion 40B of the regulating member 40, and the movement of the movable member 30B to the second position is prevented. 30B returns to the first position.

If the subject has low brightness, only the energization time should be set to a long time according to the low brightness, but if the exposure time is long, the camera shake of the photographer will be adversely affected. Good.

In such a case, the first current is supplied to the plunger solenoid 50 by a signal from the control unit to
Aspirate 50B to the left. Then, the restricting member 40 rotates counterclockwise against the return spring 43, the bent portion 40B retracts from the movement locus of the movable member 30B, and thereafter the supply current is switched to the second current. When the coil 30C of the monostable high-speed control solenoid 30 is energized, the movable member 30B moves from the first position to the second position, and the drive pin 30E drives the shutter blade 23 to fully open. The opening 20A acts as a diaphragm to perform exposure, and after the end of energization, returns to the first position by the attraction force of the permanent magnet 30D again to complete exposure.

Therefore, when not regulated by the regulating member, the shutter blades are fully opened, and the energizing time for obtaining the same exposure amount may be short.

In the embodiments described so far, the regulating member 40 is movable when the electromagnetic drive device (specifically, the plunger solenoid 50) of the regulating member 40 is not energized or the second current is not supplied. It is in the movement locus of the member 30B and has a structure for preventing the movement of the movable member 30B. This is because, in general shooting, it is intended to save the power supply battery in consideration of the fact that the frequency of shooting a high-brightness subject is higher than that of a low-brightness subject. On the other hand, in a state in which the electromagnetic driving device of the regulating member 40 is not energized or in a state in which the second current is supplied, the regulating member 40
A structure may be employed in which the movable member 30B is retracted from the movement locus of B and does not prevent the movement of the movable member 30B. In the former structure, the first current is supplied to the plunger solenoid 50 and the regulating member 40 is moved to the movable member.
After retracting from the movement trajectory of 30B and then switching to the second current, the monostable high-speed control solenoid 30 is energized,
If an accident such as dropping of a battery or interruption of a power supply line occurs when the shutter blade approaches the maximum opening, the following phenomenon may occur. In other words, the regulating member 40 moves within the movement trajectory of the movable member 30B due to the cutoff of the current supply to the plunger solenoid 50, and the movable member 30B cuts off the current supply to the monostable high-speed control solenoid 30. As a result, the movable member 30B comes into contact with the bent portion 40B of the regulating member 40 from the opposite side due to the action of the permanent magnet 30D due to the action of the permanent magnet 30D, and the shutter may be left open in the intermediate opening state. There is. However, with the latter structure, when the power supply is cut off, the regulating member 40 always retreats from within the movement trajectory of the movable member 30B, so that such a shutter opening accident can be prevented.

FIG. 3 shows a photographing lens extension mechanism which is activated according to the result of the automatic distance measurement.

A photographing lens 60 and a lens holder 61 for accommodating the photographing lens 60 correspond to another example of the operating member according to the present invention. 61A is a flange formed on the outer peripheral portion of the lens holder 61, 62 is a guide pin provided on the flange 61A, and the guide pin 62 is a circle of the flange 61A in a state parallel to the optical axis of the photographing lens 60. A total of three are provided at positions where the circumference is divided into three. 63 is the flange 61A
Is an operating portion formed by partially extending the outer periphery of the actuator.

64 is a part of a lens holding member fixed to the camera body, 65 is a guide tube formed on the front surface of the lens holding member 64, and the guide tube 65 is centered on the optical axis of the taking lens 60. A total of three guide pins 62 of the lens holder 61 are inserted and supported at positions obtained by dividing the circumference of the lens holder into three parts.

Therefore, the lens holder 61 is provided with the guide pin 62 and the guide cylinder.
By being fitted with the lens 65, the lens holding member 64, that is, the camera body, is attached and supported so that it can slide forward and backward in the optical axis direction indicated by the arrow.

On the other hand, reference numeral 70 denotes a plunger solenoid for moving a lens corresponding to another example of the first electromagnetic driving device according to the present invention, 70A denotes a movable iron core thereof, and 66 denotes a pressing plate fixed to the tip of the movable iron core 70A. When the first current according to the present invention is supplied to the plunger solenoid 70, the movable iron core 70A is sucked and sucked in parallel with the optical axis direction indicated by the arrow, and the movable iron core 70A
Of the solenoid 70 comes into contact with the bottom surface of the solenoid 70 and stops.

Reference numeral 67 denotes a lens holder which is disposed between the upper surface of the guide cylinder 65 and the lower surface of the flange 61A by inserting a guide pin 62 therethrough.
A compression spring for urging the flange 61A in the extension direction is a flange 61A.
And is fixed to the lens holding member 64 by the receiving plate. Therefore, the position of the lens holder 61 shown in FIG.
The second position corresponds to a position where the lens holder 61 is retracted by the operation of the plunger solenoid 70 in the present invention.

Each of the first and second electromagnetic drive devices operates using one battery built in the camera body as a common power supply.

FIG. 4 shows the monostable high-speed control solenoid 30 and a plunger solenoid for a regulating member and for extending a lens.
FIG. 4 shows a drive circuit diagram of 50A and 70 and a time chart of the operation based on the drive circuit diagram. The exposure operation by the camera of the present invention is performed as follows. When the shutter release button 2 (FIG. 5) of the camera of the present invention is pressed, photometry, distance measurement, and the like are performed in the initial stroke of pressing, and the shutter release is performed in the latter half of the pressing stroke. .

When the shutter release button is not pressed, the monostable high-speed control solenoid 30 and the plunger solenoids 50A and 70 are not energized, and as shown in FIG. Solenoid 30
The movable iron core 30A is located at the lower limit position of its swing and the shutter blade 23 is closed, while the plunger solenoid 50
The movable iron core 50B of A is located at a position protruding rightward, and the bent portion 40B of the regulating member 40 is positioned within the movement locus of the movable member 30B.

On the other hand, in FIG. 3, the movable iron core of the plunger solenoid 70 is shown.
Since 70A has lost the biasing force, the lens holder 61 is extended by the biasing force of the compression spring 67, the flange 61A abuts on the receiving plate 68, and the photographing lens 60 is placed at the in-focus position on the near point side. I have. That is, the operating members referred to in the present invention are all in the first position.

When the release button 2 is pressed, photometry and distance measurement are performed in the initial stroke, and the control unit switches the outputs of OUT1 and OUT3 independently based on the results of photometry and distance measurement. When OUT1 goes LOW, the transistor TR1 turns ON, the plunger solenoid 50A operates, and the movable iron core 50B moves in the second position direction. However, when the movable iron core 50B reaches the second position, OUT1 becomes HIGH. Become. TR3 when OUT3 goes LOW
Is turned ON, the movable iron core 70A reaches the second position, and OUT3 becomes HIGH as in the case of OUT1. In the vicinity of the end point of the release button pressing stroke, OUTφ is LOW, that is, TRφ is turned ON, the monostable high-speed control solenoid 30 is activated, and the shutter is driven.
OUT3 is HIGH.

The drive circuits for the plunger solenoids 50A and 70 include:
The transistor TR21 or TR22 is connected via the resistor R1 or R3, and the transistors TR21 and TR22 are turned on when OUT2 becomes LOW. OUT2 goes LOW after the release button is pressed, and
High after UTφ changes from LOW to HIGH.

When OUT1 goes LOW by pressing release button 2, TR1 also goes
TR2 is also turned on, the first current for driving the plunger solenoid 50A flows, and after the movable iron core 50B reaches the second position, OUT1 is HIGH, and thus TR1 is turned OFF. At this time, OUT2 remains LOW, that is, TR21 remains ON, and the action of the resistor R1 causes the plunger solenoid 50A to move the movable iron core 50B.
Cannot be moved, but a second current capable of holding the movable iron core 50A at that position is supplied, and the movable iron core 50B is held at the second position. When OUT1 is HIGH from the beginning, only OUT2 is LOW, TR1 is OFF and TR21 is ON, so the second current is supplied to the plunger solenoid 50A from the beginning, and the movable iron core 50B is It does not move from the first position and stops as it is. When OUT3 becomes LO by pressing the release button 2, the movable iron core 70A is held at the second position in the same manner as in the case of OUT1.
When 3 is HIGH, the plunger 70A does not move from the first position in the same manner, but remains stopped.

Therefore, when OUTφ becomes LOW, the control unit performs OUT1 and OUT3 by the initial stroke of the release button 2 pressing.
Plunger solenoid 50A regardless of HIGH / LOW switching
And 70 are supplied with the second current only. That is, when the monostable high-speed control solenoid 30 drives the shutter, the current is in a stable state regardless of the subject condition. In other words, the second electromagnetic drive according to the present invention operates only when the second current is supplied to the first electromagnetic drive. When OUTφ goes LOW, both OUT1 and OUT3 are HIGH, and the second electromagnetic drive device is operating with the load on the power supply being minimal.

Next, an example of the exposure operation including the specific operation of the mechanism will be described.

Photometry and distance measurement of the subject are performed by the initial stroke of the release button 2. For example, when it is determined that the brightness of the subject is lower than a predetermined level and the distance to the subject is on the near side, the control unit in FIG. As a result, OUT1 becomes LOW, the first current referred to in the present invention is supplied to the plunger solenoid 50A, and the movable iron core 50B is attracted.

When the movable iron core 50B is sucked, the regulating member 40 rotates counterclockwise against the return spring 43 to retract the bent portion 40B from within the movement locus of the movable member 30A, so that the shutter blade 23 is fully opened. , And exposure corresponding to a low-luminance subject becomes possible.

On the other hand, the plunger solenoid 70 has the first
Is not supplied, the photographing lens 50 is kept stopped at the in-focus position on the near point side. Also as mentioned above
OUT1 LOW is set to HIGH immediately after the operation of the movable iron core 50B.

Since OUT2 becomes LOW almost simultaneously with OUT1 by the control unit, even after OUT1 becomes HIGH, the movable iron cores 50B and 70A cannot be moved to the plunger solenoids 50A and 70, but the movable iron core 50B and A holding current capable of holding 70A at the current position is supplied. With this current, the regulating member 40 is held at the retracted position, and the lens holder 51 remains at the near-focus position.

Therefore, only a relatively small current flows through the plunger solenoids 50A and 70, and the movable iron cores 50A and 70
Will be held in each position.

Since the release button 2 is in a two-step operation, OUTφ becomes LOW by a continuous pressing operation of the release button 2, and the monostable high-speed control solenoid 30 is energized for a time corresponding to the luminance of the subject, The shutter blade 23 opens and closes. In this case, since only the holding current is supplied to the plunger solenoids 50A and 70, the monostable high-speed control solenoid 30 is energized from a stable power supply. In addition, an efficient and highly accurate shutter operation is performed.

Photometry and distance measurement of the subject are performed by the initial stroke of the release button 2. For example, when the brightness of the subject is lower than a predetermined level and the distance to the subject is on the far side, the HIGH / LOW switching from OUTφ to OUT3 is controlled. FIG. 4 (b)
It is performed as shown in the time chart.

That is, as a result of the initial stroke of the release button 2, the control unit first sets OUT1 and OUT2 to LOW in this order. As a result, the first current is supplied to the plunger solenoid 50A,
The movable iron core 50B is sucked and moves in the second position direction.
When the plunger 50B reaches the second position, the regulating member 40 retreats from the movement trajectory of the movable member 30B and OUT1 switches to HIGH, but OUT2 remains LOW, so the plunger solenoid 50A
Is supplied with the second current, the movable iron core 50B is held at the second position, and the preparation for the shutter operation for the low-luminance subject is completed. After OUT2 becomes LOW, the second current is also supplied to the plunger solenoid 70.
The plunger solenoid 70 does not operate with this current.

When a predetermined time elapses after the movable iron core 50B reaches the second position, the control unit sets OUT3 to LOW, whereby the first current is supplied to the plunger solenoid 70, and the movable iron core
70A is sucked and moves in the second position direction. Movable iron core 7
When 0A reaches the second position, the taking lens 50 stops at the far-side in-focus position, and OUT3 switches to HIGH. But OUT2 is LO
Since it remains at W, the second current is continuously supplied to the plunger solenoid 70 in the same manner as the plunger solenoid 50A, the movable iron core 70A is held at the second position, and the lens extension for the far side subject is completed.

In this state, it waits for the release button 2 to be pressed to the second half stroke, and when the release button 2 is further pressed to enter the second half stroke, OUTφ becomes LOW for the time calculated based on the photometry result, The shutter operates. OUT
When φ becomes HIGH, OUT2 also becomes HIGH after a predetermined time, the regulating member 40 and the lens holder 61 return to the first position, and a series of exposure operations is completed.

〔The invention's effect〕

Advantageous Effects of Invention According to the present invention, in a camera having an electromagnetic shutter mechanism operated by a plurality of electromagnetic driving devices, it is possible to open the full-open and half-open shutter blades with an extremely simple configuration mechanism, and furthermore, a constant voltage circuit which is complicated and expensive A camera provided with a high-performance electromagnetic shutter mechanism in which a shutter is opened and closed by electromagnetic driving that operates in a stable state without using such a device has been provided.

[Brief description of the drawings]

FIG. 1 is an external view of a shutter device provided in the camera of the present invention, FIG. 2 is a main part mechanism diagram of the shutter device, FIG. 3 is a main part configuration diagram of a lens extension mechanism provided in the camera, and FIG. (A) and (b) are a drive circuit diagram and a time chart of the shutter device and the lens extension mechanism, FIG. 5 is a front view of the camera, and FIG. 6 is a configuration diagram of a monostable high-speed control solenoid. Reference numeral 20: shutter base plate, 23: shutter blade 30: monostable high-speed control solenoid 30A: movable iron core, 30B: movable member 40: regulating member, 40A, 40B: bent portion 60: photographing lens, 61: lens holder 62 ... Guide pin, 64 ... Lens holding member 50A, 70 ... Plunger solenoid 50B, 70A ... Movable iron core

Claims (2)

(57) [Claims] A second electromagnetic driving device for opening and closing a shutter blade via a movable member; an operating member having a function of preventing movement of the movable member on the way; Or a first electromagnetic driving device for restricting the operating member to the second position, wherein the control unit controls driving of the first and second electromagnetic driving devices, and regulates the operating member to the first position by the first electromagnetic driving device. When the movement of the movable member is stopped halfway, the shutter blade is half-opened by the driving of the second electromagnetic driving device, and the operating member is regulated to the second position by the first electromagnetic driving device. Is not limited to the movement of the movable member,
A camera comprising an electromagnetic shutter mechanism, wherein a shutter blade performs a full-opening operation by driving a second electromagnetic driving device. 2. The first and second electromagnetic driving devices are driven by a common power supply, and the first electromagnetic driving device is a first electromagnetic driving device for moving the operating member from the first position to the second position. And the current is smaller than the first current and the operating member cannot be moved from the first position to the second position. However, after the operating member is moved to the second position, it is moved to the second position. The second electromagnetic driving device is driven by a second current that can be held in a position, and the second electromagnetic driving device is driven in a state where a second current is supplied to the first electromagnetic driving device. The camera according to range (1).