JPS5875134A - Automatic film winding device of camera - Google Patents

Abstract

PURPOSE:To reduce overload of a motor and damage due to a fault of a winding mechanism or a stretch of a film, by detecting a noise in the course of rotation of a motor, and intercepting electric supply to the motor after the fixed time has passed after stop of this detecting signal. CONSTITUTION:When a motor Mo is rotated and a film is wound up, a voltage variation is generated across the armature of the motor. As for this voltage variation noise, its DC portion is eliminated by a high-pass filter consisting of a capacitor 324 and resistance 307, a noise component only is passed, is amplified by an operational amplifier OP1, its output is connected to the base of a transistor 301 through a resistance 308, and this transistor 301 is switched. The collector terminal of this transistor 301 is connected to the clear terminal of a timer 313, and when rotation of the motor is stopped and no noise is generated by the final stretch of the film, or a fault, etc., electric supply to the motor is cut off after the fixed time has passed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic film winding device for a camera, and more particularly to an overload control circuit for a drive source in an electrically driven camera using a motor.

In recent years, cameras have become increasingly automated, and film winding is also becoming automated, but such cameras still use built-in motors or attachable motors as drive sources. These automatic film winding devices are generally linked to the V-Z operation of the camera, and the winding starts by starting the motor and driving the mechanism. The switch is automatically turned off when the motor stops operating.

As described above, the conventional 9-film automatic winding device does not cause any problems when the film is being wound normally, but if there is a failure in the winding mechanism or the film is stretched, the winding may be interrupted midway. At this time, power continues to be supplied to the motor, so there is a risk that the motor will be overloaded and damaged due to excessive current. Furthermore, when the loaded film was finished shooting, the film would sometimes become overloaded, similar to the situation in the case of tension shooting. Conventionally, there are methods to stop the power supply to the motor by leaking excessive current from the motor, and methods to automatically stop the power supply to the motor after a certain period of time has passed since the start of energization of the motor. Proposed. In these conventional methods, fluctuations in power supply voltage,
The ninth factor is that load fluctuations are taken into account due to thermal changes, the type of film, etc. In the former case, it is difficult to set an excessive current value, and in the latter case, it is required to set a fixed time longer than necessary, so the motor and control elements There was a point where the overload time became longer.

The object of the present invention is to provide an automatic film winding device that eliminates the drawbacks of the conventional devices as described above.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a perspective view showing the main parts of a camera to which the present invention is applied, and has an electric motor and speed reduction mechanism for winding a MoFi film, charging the shutter, and rewinding the film.

1 is a gear fixed to the motor shaft, 2, 3, 4.5 is the body, gears forming a moving gear train, 6 is a sprocket gear fixed to the shaft 7 of the #'i sprocket 8, 9 is the sprocket shaft 7 It is a fixed pin that fits into the clutch groove 8aK provided above the sprocket 8. 1oFi intermediate gear,
1IFi spool gear, 12 indicates a film take-up spool. 13 is an intermediate gear meshing with gear 4, 14IIi shutter charging gear, and charging cam 1 is mounted on the top surface.
4m is fixed. A charge lever 15 is pivotally supported by a shaft 17, and includes an arm 15a that engages with the core cam 14a and an arm 15b that engages with the shutter mechanism.

18, 19, 20, and 21 are gears forming a rewinding gear train, and 22 is a rewinding gear equipped with a well-known rewinding fork. In the illustrated winding state, the gear 18 is disengaged from the sprocket gear 6, so that the rotation of the motor is not transmitted to the rewinding gear 22. The lower end of the sprocket shaft 7 is formed as a rewind button that protrudes outward from the bottom cover of the 7dti camera, and when pushed up in the direction of arrow B, the following occurs:';/9
i) When the sprocket 8 is disengaged from the G clutch direction and the interlock between the sprocket 8 and the drive gear train is cut off, the gear 1 6 rises above "1" 1 meshing with the gear 5 and engages the gear 10. is disengaged and meshes with the gear 18 of the rewinding gear train, thereby switching from the winding state to the rewinding state. Reference numeral 16 designates a locking lever that engages with the groove 7 when the sprocket shaft 7 is pushed up to hold the shaft in the retracted state, and reference numeral 16 & represents a spring that biases the lever in the locking direction. A winding disc 23 is integrally and rotatably fixed to the gear 5.

Reference numeral 24 denotes a winding detection lever having a distal end 24at which engages with the notch 23m of the winding stopper disc 23. The lever 24 is pivotally supported by a hook 25, and is supported by a spring 26 so that its distal end is always in contact with the outer periphery of the disc 23.
It is energized by When the motor rotates, the sprocket 8 rotates once through the drive gear train, and the film is advanced by one frame, and when the charge cam 14m rotates once, the shutter charge is completed through the lever 15, and the gear 5 also rotates once. The tip of the detection lever falls into the notch 23aiC of the hoisting disk and detects the completion of hoisting. A movable contact piece Sm of a changeover switch & of the circuit shown in FIG. Fixed contact pieces Sb, Se, and Sd are arranged on the switch board, and the lever 2
When the tip 24m of 4 is in contact with the outer periphery of the disc 23, the movable contact piece Sa contacts the fixed contact pieces Sb and SdK to connect the power source E and the motor Mo, and when the winding completion is detected, the movable contact piece Sa contacts the fixed contact pieces Sb and SdK.
Short-circuit both poles of the motor in contact with c. , it looks like this.

34 and 35 are shutter blades each having a plate-shaped opening QeQ, and are loosely engaged with the pins 38 and 39 on the shutter operating lever 36, so that when the lever 36 is rotated clockwise around the shaft 37, the blades are opposite to each other. It opens by sliding in the direction, and closes by rotating the lever 36 counterclockwise.

40 is a spring that biases the lever 36 in the opening direction, 31d lever 36t - a tension lever that locks in the closed position, and the shaft 32
The bent portion 31b is pivoted by the spring 33 and is energized by the spring 33.
is adapted to engage with a notch 36m of the lever 36. 42tj A shutter closing member having an arm 42c that engages with the actuating lever 36, and is supported within the camera so that it can slide parallel to the shutter blade while being guided by a cover 42e and a pin 43. 42m is an arm that engages with the charge lever 15, and the charge cam 14 engages the lever 15 during winding.
When rotated counterclockwise, it is pushed by its tip tSa, charges the spring 44, and slides in the direction of the arrow, and the protrusion 42d at the rear end engages with the tip 45m of the locking lever 45 to reach the charging position. It seems to be locked in.

The locking lever 45 is pivotally supported by a shaft 46 and biased clockwise by a spring 47. Reference numeral 48 denotes an electromagnet in the shutter circuit, which, when energized, attracts the rear end 45b of the locking lever and rotates the locking lever (-) against the spring 47 to close the closing member 4.
Activate 2.

42b is connected to the detection lever (-24) via the intermediate lever 27.
The intermediate arm 1 (-27 is pivoted by a shaft 28, is always biased by a spring 29 to engage with the arm 42b, and the other arm 27e is connected to the rising portion 24b of the company detection lever 24. engages and detects shutter closing operation/(-
tell to. 3G is a shutter release button provided above the tension lever 31, and is given an upward return behavior by a spring 30c. Sl is a switch for supplying power to the shutter circuit. Ss is a normally closed switch for supplying power to the strobe circuit and is provided below the release button.

Reference numeral 50 denotes a strobe device that is slidably housed within the camera, and is biased upward by a casing or a spring 56 that includes an arc tube 51. Normally, a protrusion 50a is locked by a tip 53a of a locking lever 53. and pop-up button 55
t - By pushing in the direction of the arrow, the locking lever or spring 57 is released.
The light emitting portion is rotated against the force to release the lock, and the light emitting portion is raised by the force of the spring 56 and set to the use position. S4 is a switch that is switched by the protrusion 50a. Reference numeral 64 denotes a knob for starting the rewind operation, the head of which is exposed outside the camera, and the tin rocket shaft 7 and detection lever 24 below it.
The groove 60d of the rewind lever 60 interlocked with the fixed pin 6
1 and is supported so as to be slidable and swingable. A small diameter portion 7m and a tapered portion 7b are provided at the upper part of the sprocket shaft 7, and a rewind lever 60tf is normally operated by a spring 62.
63, the arm 60b engages with the small diameter portion 7a, and when the sprocket shaft is pushed up and switched to the rewinding state, the arm 60b is pushed by the tapered portion 7b and rotates counterclockwise due to the grip of the bottle 61. The bending arm 60m at the tip becomes in a state where it can engage with the rising portion 24eK of the detection lever 24.

In this state, when the knob 64t is moved in the direction of arrow C against the spring 65, its leg 64a engages with the protrusion 60eK, causing the lever 60t to slide in the same direction.
engages with the rising portion 24C to move the detection lever 24 around the shaft 25 against the spring 26. As a result, the switch Sl contact piece 79m connects the contacts Sb and 8dl to start the motor.

Fig. 2 is a circuit connection diagram showing an example of an automatic film winding device by Takaaki Moto. In the circuit, the electromagnet is energized with the output of 92 elements.
This is a well-known way to do so, and the details will be omitted. A changeover switch S as shown in the first diagram is provided between the motor Mo and the battery E, so that when contacts 8b and Sd are connected, power is supplied to the motor, and when contacts 5bxSc are closed, both poles of the motor are short-circuited. It has become. Reference numeral 304 denotes an NPN (NPN) transistor for MoI II-Mom operation, and its base is connected to a control OR circuit 316.

310 is a switch that is closed in conjunction with the movement of the rewind start knob 64 in the direction of arrow C;
17 is set to H level, the control OR circuit 316 output is set to H level, and the motor driving transistor 304 is turned on to perform rewinding. 320 is a power supply unit for controlling the motor driving transistor 3041. Then, the intercept Sa of switch S8 is S
b, supplies power supply voltage Vce to the circuit when connected to Sd.

Next, the operation of the cameras shown in FIG. 11 and FIG. 2 will be explained.

Fig. 1/Ii Assuming that the flash is completed and the strobe is in the use position, at this time it is assumed that the charging light is emitting light.From this state, if you press the release button 3 (in the direction of the arrow L) , when the lower part 30bK of the button is pressed, first the switch S1 opens and the power supply to the strobe is cut off.Then, the switch S1 is opened and the power supply to the strobe is cut off.
, is closed, and power supply to the shutter control circuit 100 is started.

When the release button 30 presses the arm axat of the tensioning lever 31 due to subsequent depression, the locking of the actuating lever 360 is released and the lever 31 is rotated clockwise around the shaft 37 by the force of the spring 40. This causes a relative movement of the shutter blades 34 and 35, and the shutter blades 34 and 35 are gradually superimposed on the aperture, the object image is projected onto the film F through the lens 41, and exposure is started. 4 After a predetermined time period corresponding to the JIL object brightness, the chamber magnet 4
8, the closing macha 45b is attracted against the spring 47, and the lever 45 completely releases the locking of the closing member 42.

At this time, the X contact (not shown) is turned on and the strobe emits light.

The closing member 42 is moved in the direction opposite to the arrow by the force of the spring 44, and the arm 420 pushes the side edge of the lever 36 and rotates counterclockwise against the spring 40 to close the shutter. The intermediate lever 27 engaged with the arm 42b of the member 42 is driven by the member 42 by the force of the spring 29, but before the member 42 stops at the final position, it hits the side surface 30a of the release button and the other end 27c is detected. It is held in a position where it is not engaged with the lever 24.

When the release button is released, the tension lever 31 is first actuated to lock the lever 36t, then the switch S is opened, and the intermediate lever 27, which closes the switch S1, is released. Lever 2
7 is pulled by the spring 29 and rotates clockwise, and the other end 27c
Press and rotate the detection lever 24, and press the tip 24a&
At the same time as releasing the locking of the hoisting disk 23 by the switch S.

The contact piece Sm was changed from 3b-3c to 5b-8dK.

A voltage is applied to the power supply section of this friend 320, and a power supply Vcc is applied to the motor control circuit. Then, the oscillator 312 operates, and the timer output Q of 313 becomes H level. On the other hand, transistors 302, 303. .

The power-up clear output, which is composed of resistors 319, 321, 322, and 323 and capacitor 318, initially turns on the transistor 303, so it goes to L level.Then, transistor 302 turns on, and the ninth 303 turns off and goes to H level. Switch. Therefore NAND II! l road 31
A latch Ig1m consisting of 4,315! The output of 3150 becomes H level, and the output of the OR circuit 316 also becomes level, turning on transistor 304 and rotating motor Mo to wind the film. Motor 1 - When Mo rotates, the motor uses a brush to switch the energization to the armature, and since this armature rotates in a magnetic field, voltage fluctuations occur at both ends of the motor due to back-up type switching. The DC component of this voltage fluctuation noise is removed by an I inno ζ 1 filter consisting of a capacitor 324 and a resistor 307, passing only the noise component, and amplified by an operational amplifier OPI, whose output is passed through a resistor 308.
t to the pace of transistor 301, causing this transistor to misswitch.

The collector terminal of transistor 301 is connected to the clear terminal of timer 313. In this circuit, if the time t is sufficiently longer than the frequency component of the noise, L level and H level are repeatedly applied to the clear terminal of the timer while the motor Mo-Ed is turning. Therefore, the timer output Q is cleared every time it goes to the L level, and the timer output Q keeps the H level, and the driving transistor 304
maintains the conductive state S, and the motor Mo continues to rotate. As the motor MO rotates in the direction of the arrow E, the sprocket 8 and the gear 12 rotate in the direction of the arrow F%G through a gear train, and the film F is wound onto the spool and the gear 14 is rotated.
The upper t-yard cam 14m also rotates in the direction of arrow H, and one rotation causes the lever 15 to reciprocate around the shaft 17.The lever 15 is closed and locked by one arm 15m during forward movement. During winding, the detection lever 24 keeps its tip 24 & in contact with the surface of the disc 23 to keep the switch & in the power supply state.
6, its tip falls into the notch 23a, and its rotation switches the swing 7S to 5b-8c to stop power supply, and short-circuits both poles of the motor MO to brake the motor. The tip of the detection lever has a notch 23
After falling into the inside a, the side surface 24c hits the cutout 23btC of the notch, so that the hoisting mechanism is always stopped at a fixed position.

Same as above condition I! is the operation when the film winding is executed normally, but if the winding of the film F is interrupted due to the final tension of the film or a mechanical cause, the motor - will only rotate for a minute and the motor will start. There is no noise at both ends of the line.The situation at this time is shown in Figure 2OA
B.C.

The waveform at point D will be explained in detail in FIG. 3. When the motor Mo is rotating and winding, the waveform of the part A is affected by high frequency noise as shown in the time up to t in FIG. 3A. When this is amplified through a bypass filter, it is amplified by the frequency noise of KA like the output B of opi, and when this is applied to the switching transistor 3010 through the resistor 308, the voltage between the base and emitter of the transistor (Vat) increases. Approximately 0
．． At a threshold voltage around 6V, the switched collector voltage becomes the waveform shown in C. This output is connected to the clear terminal 1/C1 of the timer 313, and when it is cleared at L level and becomes H level, counting starts. When the film is finished and t hours after the start of winding, the motor stops rotating and the waveform of A becomes the third waveform.
As shown in the figure, the signal becomes a signal free of high-frequency noise, and the output BFi of the OPI becomes the CΦ level. Therefore transistor 30
After 1 h off, the collector (:') #iH level is reached and the timer 313 continues counting iu. When 12 hours have elapsed since the clear terminal went from the H level, the timer output changes from the H level to the L level, inverting the latch circuit output and changing the output from the NAND 315 from the t-H level to the L level. OR circuit 3160 human power becomes L level, so its output becomes L level VC and motor drive transistor 3
041 #7 L% Cut off the power to the motor, like this l
This eliminates overload on motor 1 and does not damage the motor or drive transistor. If you want to rewind after that, turn on KFi, switch 310,
The output of the inverter 317 is set to H level Ic: L/, O
This can be done by setting the output of the R circuit 316 to the tH level, turning on the drive transistor/transistor 304t, and rotating the motor.

As mentioned above, according to the town of Honbuki, it detects noise while the motor is running, cancels the timer with the signal from here, and issues a control signal only when the motor has stopped, cutting off power to the motor. Therefore, the timer can be set at any time regardless of the time. Moreover, since this time T only needs to be sufficiently longer than the period of high-frequency noise, it is possible to set a relatively short time, reduce the burden of overload on the motor, and reduce the load on the motor drive transistor.
You can also use small ones.

Furthermore, since the timer setting time can be shortened, it can be constructed with a lower cost and smaller circuit than the conventional method of starting the timer from the start of winding, and has many features such as 0, which has a large effect on miniaturization. It can be used as a device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the main parts of a camera using the automatic film winding device according to the present invention, FIG. 2 is a circuit connection diagram showing one embodiment of the automatic film winding device according to the present invention, and FIG.
The figure is a waveform diagram of voltages at various parts in the circuit shown in the second figure. . 1oo--Shutter control circuit, SS...times M 10
G power supply switch% Mo...Motor% S*-
+-Motor drive selector switch, 32G-...Motor drive circuit power supply, 310-...Rewind switch, 3
12--Oscillator for timer operation, 313--Timer.

Claims (1)

[Claims] Film winding is automatically carried out by a motor.In an automatic film winding device for a camera equipped with a motor drive control means, the film winding device is equipped with means for detecting a noise component generated at the terminal of the motor when the motor rotates. An automatic film winding device for a camera, characterized in that it is equipped with a motor drive stop means 1 that detects whether or not noise is generated when the motor is energized, and shuts off the energization to the motor after a certain period of time has elapsed since the nuclear detection signal has stopped. .゛