JPS6346403B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor control circuit most suitable for an electric self-processing camera.

Conventionally, the film unit is equipped with a film unit feeding mechanism driven by an electric motor and a pressure roller, and a film unit which has been subjected to imagewise exposure and is capable of being processed by diffusion transfer photography is fed between the pressure rollers by the film unit feeding mechanism. An electric self-processing camera is well known in which the rotational force of a pressure roller applies pressure to the image while sending it out of the camera.

By the way, in order to control the rotation of the electric motor in this type of self-processing camera, the electric motor starts rotating in conjunction with the shutter release, etc., and then stops rotating after a fixed rotation of a mechanical constant rotation mechanism, or the film unit In the former case, if the film unit slipped between the pressure rollers, the electric motor would stop during the pressure process. However, the latter type had problems such as the mechanical switch's operation being delicate and the risk of failure being high.

The present invention has been made in view of the above-mentioned conventional problems, and is devised so that the rotation of an electric motor can be accurately controlled using an electrical control circuit that ensures reliable operation. The film unit is equipped with a film unit feeding mechanism driven by a motor and a pressure roller, and a film unit which has been imagewise exposed and is capable of being processed by diffusion transfer photography is fed between the pressure rollers by the film unit feeding mechanism, and the film unit is fed between the pressure rollers. In a self-processing camera that sends the electric motor to the outside of the camera while being pressurized with the rotational force of the electric motor, the electric motor is turned on in conjunction with a shutter release, A switch is turned off when the film unit is fed between the pressure rollers by the film unit feeding mechanism, and when the switch is turned on, the shutter means is opened and closed, and in conjunction with the closing operation of the shutter means, the motor switch is turned off. A shutter circuit that turns on the motor switch and turns off the motor switch when the switch is turned off, and a shutter circuit that detects the current flowing through the electric motor, and when the current flowing through the electric motor is higher than a reference value, keeps the motor switch on and turns on the electric motor. and a current value detection circuit that turns off the motor switch when the current is lower than a reference value, and the shutter circuit and the current value detection circuit are connected to the motor switch via an OR circuit. It is something to do.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the self-processing camera includes a photographing lens 2 having a distance ring 1, a square pyramid lens barrel 3 supporting an exposure mechanism (not shown), etc. on the front side, and The camera body 4 has a relatively flat, approximately rectangular box shape, and the film loaded into the camera body 4 can be loaded by pressing down the shutter button 6b provided on the left side 5 of the camera body 4 while looking through the window viewfinder 6a. Imagewise exposure is provided to a diffusion transfer photoprocessable film unit U in the pack 7.

As shown in FIG. 2, the film pack 7 is stored in a relatively flat rectangular box-shaped pack body 7 with an exposure frame opening 7a at the front, in which a large number of film units U with the same orientation are stacked one on top of the other. After the shutter release is completed, the electric motor M of the film unit feeding mechanism (described later), which is provided on the side surface of the left side 5 of the camera body 4, rotates.
A feeding claw (described later) that fits into a notch 7c in the pack body 7 feeds the exposed film unit U from the unit delivery opening 7d between the pair of pressure rollers 9, 9. While being pressurized, the film unit is sent out to the outside of the camera through a slit-shaped film unit outlet 10 provided on the upper surface of the camera body 4.

Next, the film unit feeding mechanism includes a relatively long reciprocating member 13, as shown in FIG. A feed claw 14 that engages with the rear end is integrally supported on the lower edge of the rear end, and guide pins 16, 16 that fit into a pair of long grooves 15, 15 provided on both sides in the longitudinal direction, It is guided so as to be able to reciprocate in the film unit feeding direction.

Below the reciprocating member 13, the winding portion is connected to a pin 17.
The fixed V-shaped return wire spring 18 is moved to the ends 18a, 18 so that an outward biasing force is applied.
b are arranged so as to be hooked on the insides of a pair of spring hook pins 19, 19 implanted above the reciprocating member 13, and at approximately the middle position of the feeding stroke of the reciprocating member 13, the reciprocating member 13
A pair of protrusions 20a, 20b protruding from the upper edge of the
The reciprocating member 13 is always positioned at an intermediate position of the film unit feed stroke (see FIG. 4a), with the reciprocating member 13 facing the outside of the ends 18a, 18b of the wire spring 18 hooked to the spring hook pins 19, 19. I am encouraging you to do so.

On the other hand, a gear 23 that is linked to the rotation of the electric motor M
A gear 21 meshing with the roller rotates one pressure roller 9 to feed out the film unit, and a gear 23 has a bifurcated arm at the wide end of the reciprocating member 13 positioned at the intermediate position. Part 1
The center of rotation O is located on the center line of the arms 13a, 13b in the width direction and slightly in front of the arms 13a, 13b.
It supports an eccentric pin 22 which is set as follows.

The arm portions 13a and 13b of the reciprocating member 13 are provided with an eccentric pin 2 which is rotated around the hour hand in the figure so as to be vertically symmetrical with respect to the rotation center O of the eccentric pin 22.
an upper riser 24 whose inner surface abuts in the first half of the rotation of 2;
The reciprocating member 13 is moved by the eccentric pin 22 to the film unit delivery position shown in FIG.
The film unit is reciprocated between the film unit engagement preparation position shown in FIG. 3 and an intermediate position (film unit engagement position) shown in FIG. 4a as a starting point. Note that the upper riser 24 is located at the rear of the lower riser 25 with a slight difference in level.

Next, for the reciprocating member 13, the reciprocating member 1
3 is returned to the film unit engagement preparation position, the locking portion 13 provided on the lower edge of the reciprocating member 13
A locking lever 26 is provided for locking and holding c.

The locking lever 26 is swingably supported at the center by a pin 27, and is biased in the direction of locking the locking portion 13c of the reciprocating member 13 by a wire spring 28 wound around the pin 27. So, positioning pin 29
is positioned at the locking position.

A release lever 30 provided for the locking lever 26 has long grooves 31, 3 provided on both sides in the longitudinal direction.
It is guided in a reciprocating manner by guide pins 32, 32 that fit into the shutter 1, and is normally positioned at the release start position by a coil spring 33, but when moved forward to the left in the figure in conjunction with the shutter release, The locking lever 26 is swung in the locking release direction via the release pin 34 on the slope 30a at the tip.

A three-pronged timing lever 35 that temporarily locks the locking lever 26 in the unlocked position is pivotally supported at the center by a pin 36, and is supported by a coil spring 37.
When the locking arm 35a is energized counterclockwise at
is located at a locking position where the end of the locking lever 26 can be locked, and is positioned by the pin 38.

Timing arm 35b of the timing lever 35
is the position of the reciprocating member 13 when the tip of the film unit U is sent between the pressure rollers 9, 9 by the forward movement of the reciprocating member 13 (see FIG. 4b). The lower cam 39 is used to swing the timing lever 35 in the unlocking direction.

For the locking lever 26, the locking lever 2
A switch 40 is provided, which is turned off when the switch 6 is in the locked position and turned on when it is in the unlocked position,
The switch 40 is connected to an electric motor M and a control circuit 41 for exposure.

As shown in FIG. 5, the control circuit 41 includes a shutter circuit that operates the shutter means when the switch 40 is turned on, a drive circuit for the electric motor M, and a current value that detects the value of current flowing through the electric motor M. It consists of a detection circuit and an OR circuit of this circuit and the above-mentioned shutter circuit.

The above shutter circuit is provided with a shutter film control magnet 42 that opens the shutter means when it is on and closes it when it is off, and also sets the exposure time of the shutter means by timing the magnet 42 when it is turned off, that is, when the shutter closes. In order to do this, the magnet 42 is switched to a resistor RFM for flash automatic FM or a Cds exposure meter RA for automatic exposure by a changeover switch 43, and a time constant circuit formed by a capacitor CT and a transistor A Schmitt circuit consisting of Tr ₁ and Tr ₂ and resistors R ₁ and R ₂ is provided.

Therefore, when the switch 40 is turned on, the magnet 42 is turned on via the transistor Tr ₃ and the shutter means is opened, while the time required for the charging voltage of the time constant circuits RFM, RA.CT to reach the threshold value is determined. , after the exposure amount setting time, transistor Tr ₁ of the Schmitts circuit is switched from off to on, transistor Tr ₂ is switched from on to off, and the transistor
Tr ₃ is turned off, the magnet 42 is turned off, and the shutter means is operated to close. Note that 44 is a synchro contact.

Next, the drive circuit for the electric motor M includes a switching transistor Tr ₄ connected in series with the electric motor M. When the transistor Tr ₃ of the shutter circuit is on, the switching transistor Tr 4 is turned off, and when the transistor Tr 3 is off, the switching transistor Tr ₄ is turned off. When the magnet 42 which closes the means is turned off, it is turned on and the electric motor M is started.

On the other hand, the current value detection circuit includes a resistor R ₀ for detecting the current value of the electric motor M, and a smoothing circuit consisting of a resistor R ₄ and a capacitor C _1. When the electric motor M is energized, the resistor R ₀ The dropped voltage generated at both terminals is smoothed by smoothing circuits R ₄ and C ₁ and output.

Also, resistors R ₅ , R ₆ , R ₇ and constant voltage diodes
A reference voltage generation circuit consisting of D ₁ is provided, and this output voltage is applied to a comparator 45 via resistors R ₆ and R ₇ .
At the same time, the output voltages of the smoothing circuits R ₄ and C ₁ are applied to the inverting input terminal - of the comparator 45;
The output signal of transistor Tr 5 is connected to be applied to the base of the transistor Tr ₄ via the diode D ₂ .

That is, the comparator 45 includes smoothing circuits R ₄ and C ₁
The applied voltage Vc from the reference voltage generation circuit R ₅ ,
Compare the applied voltage VD from R ₆ , R ₇ , D ₁ and calculate VC
> VD, the output is low level, and when VC < VD, the output is high level. In other words, when the current flowing through the electric motor M is higher than the reference value, the output is low, and the transistor Tr ₄ is While keeping it on to continue rotating the electric motor M, when the energizing current becomes lower than the reference value, the output becomes high,
The transistor Tr ₄ is turned off to stop the electric motor M.

The current value detection circuit and the shutter circuit both work to turn on the transistor Tr ₄ of the drive circuit, so the diode D is connected so that the transistor Tr ₄ is turned on when either output signal becomes low. An OR circuit consisting of ₂ and _D3 is provided to prevent mutual buffering.

In the self-processing camera configured as described above, when the shutter button 6b of the camera body 4 is pressed down, the release lever 30 is moved to the left as shown in FIG. 26 in the unlocking direction to release the shutter (see Fig. 6A), and while the switch 40 is turned on by the locking lever 26, the locking lever 2
6 is locked and held at the unlocked position by the timing lever 35. Initially, the reciprocating member 13, which is in the film unit engagement preparation position, is moved forward to the intermediate position by the biasing force of the return wire spring 18 when the lock is released, and the feed pawl 14 engages with the rear end of the film unit U.

When the switch 40 is turned on (see FIG. 6B), the transistors Tr ₂ and Tr ₃ of the control circuit 41 are turned on, and as shown in FIG. 6C, the magnet 42 is turned on and the shutter means is opened. , after a predetermined exposure amount setting time by the time constant circuits RFM, RA, CT, _the transistors Tr ₁ and Tr ₂ of the Schmitt circuits Tr ₁ , Tr 2 , R ₁ , and R ₂ are inverted, and the transistors Tr ₃
The magnet 42 is turned off and the shutter means is closed.

By turning off the transistor _Tr3 , the switching transistor _Tr4 is turned on via the OR circuit, and the electric motor M is started.

When the electric motor M is started, the pressure roller 9 is rotated by the gear 21 to feed the film unit, and the eccentric pin 22 is also rotated by the gear 23 in the direction of the hour hand.

Due to the rotation of the eccentric pin 22, the eccentric pin 22
If the reciprocating member 13 is initially stopped at the left position with respect to the upper and lower risers 24 and 25,
During the first half of the rotation of the eccentric pin 22, the reciprocating member 13 is moved forward via the rising edge 24 against the biasing force of the return wire spring 18, as shown in FIG.
The exposed film unit U engaged with the camera body 4 is fed between a pair of pressure rollers 9, 9, and the film unit U is pressurized by the rotational force of the pressure rollers 9, 9, while the film unit U of the camera body 4 is It is sent out from the unit outlet 10 to the outside of the camera.

When the tip of the film unit U is sent between the pressure rollers 9 by the forward movement of the reciprocating member 13, the lower cam 39 of the reciprocating member 13 swings the timing lever 35 in the unlocking direction to release the locking lever. 36 is released, the locking lever 36 returns to the locking position, and the switch 40 is turned off.

When the switch 40 is turned off, the output signal from the shutter circuit (the signal that turns on the transistor Tr ₄ ) disappears, but since the film unit U is being pressurized by the pressure rollers 9, the electric motor The load on electric motor M has increased since before the switch 40 was turned off.
As shown in _{FIG .}
The applied voltage VC and the reference voltage generator R ₅ , R ₆ , R ₇ ,
The applied voltage VD from D ₁ becomes VC>VD, and the output signal of the comparator 45 becomes low level as shown in FIG. 6, maintaining the on state of the transistor Tr ₄ through the OR circuit. , the electric motor M continues to rotate.

When the reciprocating member 13 is moved forward to the film unit feeding position, the eccentric pin rises upward 24.
The reciprocating member 13 is moved back to the intermediate position again by the biasing force of the return wire spring 18, as shown in FIG. 4c.

When the rotation of the eccentric pin 22 is in the second half, the reciprocating member 13 is moved back by the eccentric pin 22 via the lower riser 25, and when the reciprocating member 13 is moved back to the film unit engagement preparation position, as shown in FIG. Locking part 1
3c is locked by the locking lever 26 and the reciprocating member 13
is held at this position, and the eccentric pin 22 is removed from the lower riser 25. From then on, the eccentric pin 22 idles until the electric motor M stops rotating.

When the pressure processing of the film unit U by the pressure rollers 9, 9 is completed and the film unit U is sent out from between the pressure rollers 9, 9, the load on the electric motor M is reduced, and the electric motor As shown in FIG. 6E, the current flow of M decreases from the predetermined value from the pressurization completion point b, and the smoothing circuits R ₄ and C ₁
Applied voltage VC and reference voltage generator R ₅ , R ₆ .R ₇ , D ₁
The applied voltage VD from VC<VD, and the output signal of the comparator 45 becomes
When the level becomes high, the transistor _Tr4 is turned off via the OR circuit, and the electric motor M comes to stop.

Next, the eccentric pin 22 is placed on the top of the reciprocating member 13.
If it is stopped at the right position with respect to the lower risers 24 and 25, the rotation of the eccentric pin 22 causes the reciprocating member 13 to move back once via the lower riser 25, but the locking lever 26 is still swung to the unlocked position by the timing lever 35, so when the eccentric pin 22 comes off the lower riser 25, the reciprocating member 13 returns to the intermediate position, and then the eccentric pin 22 moves the reciprocating member 13 to the upper riser 24. As described above, the reciprocating member 13 is moved forward through the
Therefore, even if the stopping position of the eccentric pin 22 is indefinite, the reciprocating member 13 can always be reciprocated once per photographing cycle.

As is clear from the above explanation, the present invention
This is a motor control circuit that turns off the electric motor, which is turned on in conjunction with the shutter release, when the applied current falls below a reference value due to a load drop as the pressure roller completes feeding of the film unit. The electric motor can be electrically controlled to stop at the same time as the pressure roller completes the pressure processing of the film unit.

Therefore, according to the present invention, since the electric motor does not stop until the film unit is completely fed out from the pressure roller and the pressure processing is completed, even if the film unit slips between the pressure rollers,
There is no possibility that the electric motor stops during the pressurization process as in the above-described conventional method, and stable pressurization of the film unit can be performed.

In addition, since the current flowing through the electric motor is detected and the timing of stopping the electric motor is determined, the failure rate is lower than that of the conventional method using delicate mechanical switches, and stable operation is maintained for a long period of time. can be guaranteed for a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a self-processing camera, FIG. 2 is a perspective view of a film pack, FIG. 3 is a front view of a film unit feeding device, and FIGS. 4a to 4c are the film unit of FIG. FIG. 5 is a motor drive circuit, and FIGS. 6A to 6F are waveform diagrams of the circuit in FIG. 5. 4... Camera body, 7... Film pack, U... Film unit, 9, 9... Pressure roller, 13... Reciprocating member, 14... Feed claw, 18... Wire spring, M
...Electric motor, 22...Eccentric pin, 24, 25...
Up/down rise, 26...locking lever, 30...release lever, 35...timing lever, 40...switch, 41...control circuit,...shutter circuit,
...Drive circuit, ...Current value detection circuit, ...OR circuit, RFM, RA, CT...Time constant circuit, Tr ₁ , Tr ₂ ,
R ₁ , R ₂ ... Schmitt circuit, 42... Magnet,
Tr ₄ ... Switching transistor, R ₀ ... Current value detection resistor, R ₄ , C ₁ ... Smoothing circuit, R ₅ , R ₆ , R ₇ ,
D ₁ ...Reference voltage generation circuit, 45...Comparator,
_D2 , _D3 ...Diode.

Claims (1)

[Scope of Claims] 1. A film unit that is equipped with a film unit feeding mechanism driven by an electric motor and a pressure roller, and capable of imagewise exposure and diffusion transfer photographic processing,
In a self-processing camera in which the film unit is fed between pressure rollers by the above-mentioned film unit feeding mechanism and then sent out to the outside of the camera while being pressurized by the rotational force of the pressure roller, a motor switch for turning on and off the above-mentioned electric motor is provided. a motor drive circuit having Tr ₄ ; a switch 40 that is turned on in conjunction with the shutter release and turned off when the film unit is fed between the pressure rollers by the film unit feeding mechanism; and a switch 40 that turns on the switch 40. a shutter circuit that opens and closes the shutter means, turns on the motor switch Tr ₄ in conjunction with the closing operation of the shutter means, and turns off the motor switch Tr ₄ when the switch 40 turns off; and keeps motor switch Tr ₄ on when the energizing current is higher than the reference value, and turns off motor switch Tr ₄ when the energizing current of the electric motor is lower than the reference value. The above shutter circuit and current value detection circuit are
A motor control circuit for a self-processing camera, characterized in that it is connected to Tr ₄ via an OR circuit.