JPS6214820B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a camera control circuit that uses a single power source to drive a motor and charge a flash device, and in particular, to a camera control circuit that uses a single power source to drive a motor and charge a flash device. The present invention relates to a camera control circuit that can avoid driving a motor and charging a flash device at the same time.

<Prior art> Various electric cameras have been proposed in the past that have a built-in motor that can wind the film and charge the shutter each time a picture is taken. Various problems have arisen due to the use of batteries housed within the main body. The biggest problem with such cameras is that due to the camera's space constraints, there is not enough space to store the battery inside the camera, so only small capacity batteries can be used, making it unavoidable to replace the batteries frequently. That is the point.

This problem becomes more noticeable when such batteries are used not only for motors but also for other purposes. For example, such a battery may be used as a power source for a strobe device.

Normally, a strobe device requires a large current of about 1 to 2 A for several seconds when charging the main capacitor, so the strobe device is built into the electric camera mentioned above, and the motor and strobe device are powered by the same battery. If you do both at the same time, a large current will flow instantly, which will consume the battery within a short period of time.

BACKGROUND ART Recently, the performance of batteries has improved, and high-performance batteries that can flow large currents, such as alkaline manganese batteries and nickel cadmium batteries, have appeared. However, even if these batteries are used, it is difficult to ensure a satisfactory usage time in the above cases.

By the way, in order to solve this problem, a means for detecting the motor power supply state and a means for detecting the power supply to the shutter control magnet are provided, and the strobe is activated only when power is not being supplied to the motor and electromagnet. A camera that charges the device is proposed in Japanese Patent Application Laid-open No. 50-97327 (corresponding to US Pat. No. 3,846,812).

Indeed, according to the camera of this invention, power is not supplied to the motor and the strobe device at the same time, and the above-mentioned inconvenience does not occur. but,
Such cameras have complicated circuit configurations, so
The disadvantages were that the cost was high and the circuit size was large.

<Object of the Invention> The present invention has been made to solve the above-mentioned conventional drawbacks, and provides a camera control circuit in which the motor is driven and the flash device is charged by a single power source. A drive terminal of the motor and a charging terminal of the flash device are connected in series to the power source, and a first short-circuit circuit short-circuits the drive terminals of the motor and a first short-circuit circuit short-circuits the charging terminal of the flash device. 2 short circuit and the 1st short circuit when the motor is operating.
opening the short-circuit circuit, and closing the second short-circuit circuit, and operating the motor without performing a charging operation of the flash device with the current from the power source flowing through the second short-circuit circuit; In response to the completion of operation of the motor, the first short circuit is closed and the second short circuit is opened, so that the motor is activated by the current from the power source flowing through the first short circuit. An object of the present invention is to provide a camera control circuit which has an extremely simple configuration and can prevent the motor from being driven and the flash from being charged at the same time by providing a switch that allows the flash to be charged without being activated. It is something to do.

<Example> Hereinafter, the present invention will be described in detail based on an illustrated example.

In FIG. 1, 101 is a camera with a built-in strobe device to which the present invention is applied, 21 is a camera release button, 22 is a film rewind start button, and 23 is a camera with a built-in strobe device.
indicates a strobe device. In the figure, strobe device 2
3 shows the state in which it is housed in the camera, and is configured such that when a pop-up button 27 is pressed, a light emitting portion (described later) of the strobe device 23 pops out to the operating position. 36 is a photographing lens, and 58 is a viewfinder.

In FIG. 2, Mo is a film winding and rewinding motor, which has a built-in speed reduction mechanism.
1 is a gear fixed to the reduction output shaft of the motor Mo, 2 is a driven gear that meshes with gear 1, 3 is a gear fixed coaxially with the shaft of gear 2, 4 is a sprocket drive gear that meshes with gear 3, and 5 is a gear that meshes with gear 2. A sprocket shaft, 6 a key rod fitted into the sprocket shaft, and 7 a sprocket. In addition, 5a
indicates the tip of the sprocket shaft that protrudes from the bottom of the camera and is used as a rewind button;
When rewinding, by pushing up the tip 5a of the sprocket shaft 5 into the camera, the engagement between the key rod 6 and the insertion groove of the sprocket is released, and the sprocket 7 is released.
Free rotation. The gear 4 has a toothed portion having a predetermined thickness in the axial direction, and switch approaches 46 and 47, which will be described later, are arranged at the tip of the shaft.
9 is a gear that meshes with the lower part of the toothed part of gear 4 in the winding mode, 9a is a film measuring cam fixed coaxially with gear 9, and 10 is fixed to the tip of rotating shaft 10 of take-up spool 13. This is a driven gear that is in constant mesh with gear 9. Axis 10a
The film and the spool 13 are frictionally connected in the same manner as in a known winding mechanism, and the film is wound onto the spool 13 when the gear 10 is driven. A gear 11 is driven and rotated by the gear 3 that meshes with the gear 4, and a charge cam 12 is fixed on the gear 11. Further, the lever 14 is moved to the shaft 1 by a pin 14a that is pressed against the periphery of the cam by the spring force of a spring (not shown).
4c as the center, and the tip 1 of the lever 14
4b activates a known shutter charge mechanism. Reference numeral 16 designates a detection lever that pivots around the shaft 15, and is biased counterclockwise by a spring 16c, and its protrusion 16b falls into the notch of the cam 9a, thereby switching a switch contact piece 44, which will be described later. Reference numerals 17 to 20 denote a group of rewinding transmission gears, and gear 17 meshes with gear 4 by moving in the axial direction of gear 4 in response to the pushing up of sprocket shaft 5 in the rewinding mode, and transmits the driving force of motor Mo. is transmitted to the unwinding fork 20a fixed to the tip of the shaft of the gear 20.

Reference numeral 22 designates a rewind mode switching button, and when pressed in the direction of the arrow, it comes into pressure contact with the switch contact piece 49 to change the contact relationship with the switch contact pieces 48 and 50. Reference numeral 23 denotes a strobe device built into the camera body, and a xenon tube 24 serving as a light emitting section emits light by a light emitting circuit to be described later. Note that the strobe device 23
is biased upward in the drawing by a spring 23a, and when the pop-up button 27 is pressed, the engagement between the tip of the lever 25 and the protrusion 23b is released, and the strobe device 23 rises from inside the camera and is ready for use. set to the position. 51 to 53 are protrusions 23b
This is a contact piece that forms a switch that is switched by engagement with the switch.

21 is the aforementioned release button, S ₁ is a switch whose closing operation is performed at the tip of the release button 21, 54 and 55 are normally closed switches whose opening operation is performed at the stepped portion of the release button 21, and 28 is a release button. The shutter tensioning levers 30 and 31, which are disengaged from the shutter drive lever 29 by the button 21 against the biasing force of the spring 59, are shutter blades and have shutter openings O ₁ and O ₂ respectively. The wedge-shaped portions of the openings O ₁ and O ₂ also function as aperture blades for a half-open shutter. The drive lever 29 is the spring 3 for opening the shutter.
5 is suspended, and each shutter blade 3 is suspended by pins 29a and 29b installed on the lever 29.
The shutter blades 30 and 31 are connected to one end of the shutter blades 30 and 31 in a floating relationship, and the shutter blades 30 and 31 are connected to one end of the shutter blades 30 and 31 by swinging the lever 29 clockwise about the shaft 32.
0 and 31 move to the right and left in the figure, respectively, and open each opening.
O ₁ and O ₂ become close to each other, and the aperture diameter is determined by the amount of overlap between the two. Reference numeral 37 designates a shutter return lever, and its tip protrusion 37a is locked to a locking portion 40b of an armature 40 of an electromagnet 41, thereby locking the lever 37 in the illustrated position against the biasing force of a spring 39. . Linear guide pins 38a and 38b are fitted into linear grooves formed in the lever 37. Note that the lever 37 is formed with a protrusion 37b that can be engaged with the side edge of the lever 29, and the shutter blades 30 and 31 are closed by moving the lever 37 to the left in the figure. Also, at this time, the bending portion 37d presses the tip 16a of the lever 16 to rotate it clockwise, and the switch contact pieces 44, 4
5 when the shutter is closed (charge not completed),
Let it close. The bent portion 37e at the rear end of the lever 37 engages with the charge lever 14 to move the lever 37 to the right during charging, thereby charging the spring 39.

FIG. 3 shows an electrical circuit applied to the second illustrated camera. In the figure, E is a power source battery, 200 is a shutter control circuit which is supplied with power through a switch _S1 , and an electromagnet 41 is controlled by the circuit 200. P is a light receiving element for photometry such as a silicon photodiode connected to the control circuit 200.
Switch contacts 54 and 55 that are opened by pressing the release button 21 are connected in series between the motor Mo and the battery E, and switch contacts 48 to 50 that are linked to the mode switching button 22 are connected in series.
Also, the lever 16 connects the switch contacts 43 to 45 that are linked to the film meter, and the strobe power supply circuit 300 connects the switch contacts 43, 44, 4.
A power supply path is formed via 8.49. or,
Switch contacts 51 to 53 are inserted into the power supply path of the strobe power supply circuit.

Above numbers 43-45, 48-50, 50-5
3, 46 to 47 are switch contacts, respectively.
For convenience, this will be referred to as a switch hereinafter. Note that the strobe power supply circuit 300 described above is a booster DC-
This is a known strobe circuit that includes circuits such as a DC converter and a main capacitor.Also, the shutter control circuit 200 normally uses the output of the light receiving element P, and when shooting in closed light, the resistance value changes depending on the subject distance. This is a known method in which the time from when the count switches 56 and 57 are closed by the shutter blade 30 until the electromagnet 41 is energized is controlled by the output determined by a variable resistor (not shown) that changes. The details are omitted.

In the above configuration, the operation of each mode will be explained next.

(1) Natural light photography mode When taking natural light photography, when the release button 21 is pressed while facing the subject, the switches 54 and 55 are opened by pressing the release button 21 in the first stage from the charging completion state shown in the second figure. , switch
_S1 becomes closed. As a result, the power supply circuit of the motor Mo is cut off, and the shutter control circuit 2
Power supply to 00 is started.

Note that at this time, the switches 51 and 52 of the strobe power supply circuit 300 are in the open state, so the power supply path is always open.

When the release button 21 releases the tension of the lever 29 by the lever 28 by the second pressing, the lever 29 is rotated clockwise by the biasing force of the spring 35. As a result, the shutter blades 30 and 31
A relative movement occurs, the openings O ₁ and O ₂ gradually overlap, the object image is projected onto the film F through the lens 36, and exposure is started. When the electromagnet 41 is energized after a predetermined period of time corresponding to the subject brightness, the end 40a of the armature 40 is connected to the electromagnet 41.
The armature 40 rotates counterclockwise against the spring 60 and disengages from the lever 37. Therefore, at this time, the lever 37
The lever 29 is moved to the left in the figure by the biasing force of the shutter blade 37b, and the lever 29 is returned counterclockwise via the side edge of the lever 29 by the protrusion 37b, and the shutter blades 30 and 31 are driven to close the shutter opening. At the same time, the lever 16 is rotated clockwise by the protrusion 37d to close the switches 44 and 45.
During this time, the release button 21 remains pressed, so the motor Mo is not driven. After that, when you release button 21, switch S ₁
is opened and the power supply to the shutter control circuit 200 is blocked, and the switches 54 and 55 are closed, so the motor Mo is connected to the battery E.
Motor Mo-switch 48/49-switch 4
4.45 - Power is supplied by the closed circuit of battery E and it starts rotating.

As a result, sprocket 7 is connected via gears 1 to 4.
is driven, and the film is fed by engagement with the perforation of the film f. Also, during this time, the lever 14 is moved to the cam 1 by the rotation of the gear 11.
2, the lever 37 is moved to the right in the drawing by its tip 14b, and the spring 39 is charged.

Upon completion of charging, lever 37 moves to armature 4.
0 and is locked in the illustrated position. When the lever 37 is fully charged, the bent portion 3
7d is separated from the side edge 16a of the lever 16, the protrusion 16b of the lever 16 comes to follow the cam 9a due to the spring 16c, but the cam 9a
When the protrusion 16b is outside the notch, the switch 4
Since the length of the lever 16 from the central axis 15 is appropriately determined so that the levers 4 and 45 are in the closed state, the motor Mo continues to rotate even after the charging of the lever 37 is completed. During this time, the sprocket 7 and the take-up spool 13 also rotate to take up the film. When the film f is fed by one frame and the gear 9 rotates once, the notch of the cam 9a also rotates once and returns to the position where it can engage with the protrusion 16b, so that the lever 16 is moved by the biasing force of the spring 16c. It rotates counterclockwise and opens the switches 44 and 45 with its tip.
Close 44 and 43.

As a result, motor Mo-switch 48/49-4
3.44-A short circuit of the motor Mo is formed, the brake is applied to the motor Mo, and the motor Mo is suddenly stopped. Winding is completed in this state, and preparation for the next photograph is completed (state shown in the second diagram).

(2) Flash photography mode To perform flash photography, press the hop-up button 27.
is pressed to move the strobe device 23 to the use position by the spring 23a. This operation opens the switch and closes the switches 51 and 52.

As in the natural light shooting mode 1 above, by pressing the release button 21, the shutter control circuit 200 is activated.
is turned on by switch S ₁ , and switch 5
With the opening of 4 and 55, the shutter blades 30 and 31 are opened and closed as described above while the power supply to the motor Mo and the strobe power supply circuit 300 is blocked, and an exposure operation based on the light emission of the strobe device 23 is performed. . After that, when the button 21 is released, the switch _S1 is opened and the switches 54 and 55 are closed.
A closed circuit is formed in the motor Mo by the same connection as described above, and winding is started. During winding, the strobe circuit 300 is not powered because the switches 43 and 44 are open. At the stage when winding is completed and switches 43 and 44 are closed to form a short circuit for the motor, battery E switches 54 and 55 are closed.
A power supply circuit for switches 43 and 44 - switches 48 and 49 - strobe circuit 300 - switches 51 and 52 - battery E is formed, and charging to the main capacitor (not shown) in the strobe circuit is started. The completion of charging of the strobe circuit 300 can be predicted to the photographer by placing a known neon tube or the like in the optical system of the viewfinder 58.

After the strobe circuit 300 is ready to emit light, if the release button 21 is pressed again, the switches 54 and 55 will open again, so power supply to the motor Mo strobe circuit 300 is prohibited, and
Flash photography will be done.

That is, while the shutter control circuit 200 is operating, the battery E
only supplies power to such circuits.

As described above, power is supplied from the battery E to the shutter control circuit 200 in synchronization with the release operation, to the motor Mo for the winding operation in synchronization with the release return operation, and to the strobe circuit 30 when the winding is completed.
Charging to 0 and charging to each circuit are performed sequentially in a time-sharing manner, and a large current is not caused to flow from the battery at the same time.

(3) Rewind mode When rewinding the film, as with a normal camera, first press the return button 5a to release the engagement between the sprocket 7 and the keyway 6, and free the rotation of the sprocket 7. Make it. By pushing up the button 5a, gear 4 and gear 9 are disengaged,
Gear 4 meshes with gear 17. Also, due to this operation, the switches 46 and 47 are brought into a closed state by the tip of the shaft 5. Next, press button 22 and switch 4.
When 9 and 50 are closed, motor Mo is connected to battery E - motor Mo - switch 49, 50 - switch 46, 4.
7--Battery E Since a closed circuit is formed, driving is started, and the fork 20a, which engages with the film winding core in a film cartridge (not shown), is rotated via gears 17-20. As a result, rewinding of the film is started. Note that in order to prevent the leading end of the film from getting caught in the cartridge, a separate switch may be provided to detect when the rotation of the sprocket 7 stops, and this switch will stop the rotation of the motor Mo. The additional configurations will be omitted since they are not directly related to the present invention.

The above-mentioned rewinding can be stopped by returning the button 22, but during rewinding, the switches 48 and 49 are opened, so power supply to the strobe circuit 300 is prohibited, and the shutter control circuit 200
Similarly, power supply is prohibited by opening switch _S1 . In addition, even in this case, switches 51 and 52
is closed, the strobe circuit 300 is connected to the motor.
A power supply path is formed in series via Mo, but since the motor load is connected in series, the strobe circuit 3
The charging current to 00 is limited and no power is actually supplied. Rewinding is completed, switch 48/49
When the strobe circuit 300 is closed, power supply to the strobe circuit 300 is started if the switches 51 and 52 are closed.

Therefore, during the time it takes to replace the film cartridge with a new one, power is being supplied to the strobe circuit 300, so with a new film loaded, the charging of the circuit is completed and the next shooting can be started immediately. becomes possible.

As described in detail above, in the present invention, power is supplied to the exposure control circuit by the camera startup operation, and power supply to additional circuits such as other winding and flash devices is prohibited; Power is essentially supplied only to the hoisting motor when the operation is canceled, and power is supplied to the strobe circuit when hoisting is completed, so a large current is not always consumed from the battery at the same time, and a small capacity battery can be used for a long time. There are advantages that a camera that can withstand use can provide.

In addition, these time-divided power supplies are performed via switches such as the release switch, exposure end switch, and winding completion switch that switch when each operation is completed, ensuring reliable power supply operations. The structure can also be relatively simple.

As a result, in addition to additional circuits such as winding and strobe devices, it is possible to provide a camera with a long service life even when other battery-driven circuits such as a date imprint circuit and display circuit are used in combination. be.

In the above embodiment, a half-open shutter control circuit is illustrated, but it may be an aperture control circuit that prioritizes the shutter speed, and the exposure control circuit does not necessarily have to be related to subject brightness or subject distance. It should be understood that in addition to determining the amount of exposure, it is also useful as, for example, a magnetic release circuit for simply starting exposure control elements such as a shutter and an aperture.

Further, the switch means exemplified as each switch is not only a mechanical switch, but also a switch means that electrically senses the operation of each member, such as a camera release member, a shutter member, etc., such as a capacitance change, a magnetic change, etc. Of course, it is possible to obtain a desired value by appropriately selecting the value.

Furthermore, in the above embodiment, in the winding/rewinding mode, the strobe circuit is connected to the battery while power is being supplied to the motor, but since the motor load is connected in series to the strobe power supply circuit, power is not actually supplied. blocked. Therefore, since power is not actually supplied to the strobe circuit while power is being supplied to the motor, a large amount of current is not simultaneously drained from the battery.
The durability of the battery is not impaired.

In the above explanation, "substantially blocking the power supply" means that the power supply from the battery is not completely blocked, but the leakage current from the battery is so small that it does not rapidly drain the battery. It means that.

Furthermore, a switch that closes in conjunction with the release button in the above embodiment is connected between the motor power supply circuit and the strobe power supply circuit, and the motor starts winding when the exposure end signal from the shutter is received, and when the winding is completed, the motor stops. Alternatively, the power supply to the strobe circuit may be stopped and the power supply to the strobe circuit may be started. However, in this case, it is necessary to keep pressing the release button while power is being supplied to the motor and strobe circuit, but a release button locking mechanism can be provided so that the locking operation is released by the strobe circuit charging completion signal and the release button returns to its original state. .

<Effects of the Invention> As explained above, according to the present invention, in a camera control circuit in which the motor is driven and the flash device is charged by a single power source, the A first short-circuit circuit that connects a drive terminal of a motor and a charging terminal of the flash device in series and short-circuits between the drive terminals of the motor, and a second short-circuit circuit that short-circuits between the charging terminals of the flash device; While the motor is operating, the first short circuit is opened and the second short circuit is closed, and the flash device is charged by the current flowing through the second short circuit from the power source. operating the motor, and in response to the completion of operation of the motor, closing the first short circuit and opening the second short circuit, so that the power source flows through the first short circuit; Since the switch is provided with a switch that charges the flash device without operating the motor using the current, the circuit configuration is extremely simple to prevent driving the motor and charging the flash device at the same time. In terms of cost and space,
Its effectiveness is extremely high.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a camera to which the present invention is applied, FIG. 2 is a perspective view showing an embodiment of the invention, and FIG. 3 is an electric circuit diagram applied to the embodiment shown in the second figure. 101...Camera, 21...Release button,
Mo... Motor, 54, 55... Release button interlocking switch, 43-45... Exposure completion and winding completion detection switch, 23... Strobe device,
200... Exposure control circuit, 300... Strobe power supply circuit.

Claims (1)

[Claims] 1. In a camera control circuit in which the motor is driven and the flash device is charged by a single power source, the drive terminal of the motor and the charging terminal of the flash device are connected in series to the power source. , a first short circuit that shorts between drive terminals of the motor;
a second short circuit that shorts between the charging terminals of the flash device; and a second short circuit that opens the first short circuit and closes the second short circuit when the motor is in operation. The motor is operated by the current flowing from the power source without charging the flash device, and in response to the completion of operation of the motor, the first short circuit is closed and the second short circuit is closed. a switch that opens the circuit and causes the flash device to be charged without operating the motor by the current from the power source flowing through the first short circuit. .