JP2984016B2 - Stop control device for film hoisting motor - Google Patents

Description

The present invention relates to an automatic film winding mechanism for a camera,
More specifically, the present invention relates to a hoist motor stop control device.

[Conventional technology]

Conventionally, as this kind of stop control device, for example,
-155336, JP-A-58-24123 and JP-A-6-24
Japanese Patent Application Laid-Open No. 2-157020 is known.
In the configurations disclosed in these publications, the stop control of the motor is performed by a wind pulse generated according to the moving amount of the film. That is, when the number of pulses reaches a predetermined value, the motor is stopped, or the film movement amount and the movement speed are obtained by the pulse, thereby determining the motor stop timing.

[Problems to be solved by the invention]

However, as the film winding speed increases, the motor tends to overrun, and it is difficult to accurately determine the stop position of the film simply by determining the stop timing of the motor using pulses, as in the past. Occurs. In addition, the film winding speed, that is, the speed of the motor, varies depending on the voltage of the battery that drives the motor and the load of the motor depending on the type of film,
If the fluctuation amount of the motor speed becomes large, there arises a problem that it is difficult to accurately determine the stop position of the film by the conventional stop control using a pulse.

The present invention does not depend on the speed of the hoist motor, and even if the power supply voltage or the motor load fluctuates.
An object of the present invention is to provide a hoist motor stop control device that can always stop a film at a predetermined position with a constant accuracy.

[Means for solving the problem]

The film winding motor stop control device according to the present invention includes: a unit for measuring a winding speed of the winding motor; a first deceleration control unit for applying a short-circuit brake to the winding motor to reduce the speed; After the deceleration control of the hoist motor by the first deceleration control means, the conduction and short-circuiting of the motor circuit are repeated in time to decelerate the hoist motor. When the winding of one frame of the film is completed while the second deceleration control means and the first deceleration control means are operating, the second deceleration control means does not execute the deceleration processing, and the motor rotates in reverse. After the brake is applied and the hoisting speed is reduced by the first deceleration control means, the file is turned on during the operation of the second deceleration control means. There is characterized in that a stop control means for applying the reverse brake when rolled up one frame, the film winding motor.

〔Example〕

 Hereinafter, the present invention will be described with reference to the illustrated embodiments.

FIG. 2 shows a control circuit of a camera to which one embodiment of the present invention is applied. The control circuit includes a microcomputer (CPU) 10 for controlling the entire camera, a microcomputer (DPU) 20 for controlling photometry and the like, a microcomputer (IPU) 30 for controlling display and the like, and a microcomputer (CPU). Lens CPU) 40. Of these, only the lens CPU 40 is provided in the lens, and the others are provided in the camera body.

The CPU 10 performs various sequence controls, AF operations, exposure calculations, and the like. For this reason, the CPU 10 includes an EE circuit 11 that generates a pulse synchronized with the aperture operation, a switch circuit 12 for inputting signals from various switches such as a photometry switch and a release switch, and motor drive circuits 13 and 14. Connected. The motor drive circuit 13 drives the AF motor 15, and the motor drive circuit 14 drives a film winding (wind) motor 16 and a mechanical charge motor 17 for mirror down and shutter charge. The CPU 10 also has an E ² PROM 18 for storing information such as the number of films and various correction values, and magnets (ESMg1 and ESMg2) for electrically holding the shutter.
And a magnet to release the locked state of the mirror (release
Mg) is connected.

The DPU 20 is connected to a CCD 21 that is a distance measuring sensor and a photometric IC 22 that outputs a voltage signal according to the luminance of the subject.
U20 performs a photometric operation and also acts as an interface for CCD21. The DPU 20 controls the flash circuit 32.

A display device (LCD) 31 for displaying various information inside and outside the viewfinder and a flash circuit 32 are connected to the IPU 30, and the IPU 30 controls these. The flash circuit 32 is for charging, triggering and quenching the built-in flash of the camera.

The lens CPU 40 is connected to the CPU 10 on the camera
Information data of various lenses is exchanged with the CPU 10, and various calculations are performed based on the data.

FIG. 3 shows a mechanism for feeding the film, which itself is conventionally known. A wind motor 16 is provided in the take-up spool 51, and an output shaft of the motor 16 projects downward from the spool 50. A small-diameter gear 52 fixed to the output shaft 51 of this motor
Linked to The hoisting gear train 54 has planetary gears 54, 55, which can be connected to a large gear 56 fixed to the take-up spool 50, while the planetary gear 55 optionally has
Gear or rewind gear train 58 at the lower end of sprocket 57
Linked to The rewind gear train 58 is a rewind fork 59
Linked to An encoder gear 60 is connected to the upper end of the sprocket 57, and the rotation of the encoder gear 60 generates a pulse (wind pulse) according to the film winding amount as described later.

When winding the film, the planetary gear 54 takes up the take-up spool.
The planetary gear 56 is engaged with the sprocket 57 and is released from the rewind gear train 58. Therefore, the wind motor 16
, The spool 50 is driven to rotate via the hoisting gear train 53 and the planetary gears 54 and the planetary gears 55
, The sprocket 57 is rotated to wind up the film. Also, at this time, the encoder gear 60 rotates to generate a wind pulse. When rewinding the film,
The planetary gear 54 is in a free state with respect to the large-diameter gear 56 side,
Further, the planetary gear 55 meshes with the rewind gear train 58. Therefore, when the wind motor 16 rotates reversely, the rewind gear train
58 is operated, and the rewinding fork 59 rotates to rewind the film.

A brush is attached to the encoder gear 60,
This brush makes electrical contact with the pulse encoder pattern shown in FIG. The pattern of the pulse encoder is included in the switch circuit 12, and outputs a signal indicating a film winding state.

One terminal of the brush of the encoder gear 60 is always connected to the ground terminal 69, and the other terminal is connected to the conductive portion 61 and the non-conductive portion.
Touch one of 62. Due to the rotation of the encoder gear 60, the brush moves on the pattern and repeats contact with the conductive portion 61 and the non-conductive portion 62, so that the conductive portion 61 periodically conducts to the ground terminal 69, and a wind pulse is generated. .
This pulse signal is detected from the terminal 63. When the brush comes into contact with the conductive portion 64, a signal indicating completion of winding of one frame of the film is output from the terminal 65.

Next, the contents of the flowchart of the film winding process (FIGS. 5 to 8) will be described with reference to a drive timing chart of the wind motor (FIG. 9).

In step 1, the wind motor 16 is started, and winding of the film is started. In step 2, a timer (100 ms) for detecting the end of the film is started. In step 3, it is detected whether or not the one-frame detection switch Sw1 has been turned off. This one-frame detection switch Sw1 is connected to the fourth
Corresponding to the terminal 65 in the drawing, the film is in the ON state as shown by reference numeral i (FIG. 9) at the normal film stop position, and is OFF as shown by reference numeral j (FIG. 9) when the wind motor 16 is rotating. It is in. If the switch Sw1 is in the ON state, step 4 is executed. If 100 ms has elapsed while the switch Sw1 is in the ON state, it is determined that the end of the film has been detected, and the film end processing is executed.

When the one-frame detection switch Sw1 is turned off, it is determined that the film is being wound, and the timer (100 ms) for detecting the end of the film is reset in step S5. Next, at step 6, it is determined whether or not the film feed detection switch Sw2 has been turned on. The switch Sw2 repeatedly turns ON and OFF a plurality of times during the feeding of one frame of the film, and this ON-OFF signal is output from the terminal 63 in FIG. This signal is in the OFF state as shown by reference numeral m (FIG. 9) at the normal film stop position, but becomes n when the winding of the film is started.
As shown in FIG. 9, ON and OFF are repeated, and a wind pulse is output. If 100 ms elapses without the switch Sw2 changing to the ON state, it is determined in step 7 that the end of the film has been detected, and the end of film process is executed.

In contrast, when the switch Sw2 changes to the ON state, the process proceeds from Step 6 to Step 8, and it is determined whether the switch Sw2 has changed to the OFF state. If 100 ms elapses without the switch Sw2 remaining in the OFF state, as in step 7, it is determined in step 9 that the end of the film has been detected, and the end of film processing is executed.

When the ON and OFF of the switch Sw2 are repeated, that is, when the wind pulse is output,
~ Step 10 is repeatedly executed, and the wind pulse is k
It is determined whether or not the number has been counted. When the end of the film is detected before the counting of the k pulses, the film end processing is executed. When the number of the k pulses is counted, a step for performing the brake control of the motor is performed.
Proceed to 11. The period from the start of rotation of the motor 16 to the detection of k wind pulses is indicated by a symbol in FIG.

In step 11, the counter for detecting the winding speed of the motor is cleared. Next, in step 12, 1m
The timer of s is started, and the interrupt processing is permitted. Thus, an interrupt is generated every 1 ms, and the interrupt routine shown in FIG. 8 is executed. That is,
In step 41, the speed detection counter is incremented, and in step 42, the 1 ms timer is reset.

In FIG. 5, a timer (100 ms) for detecting the end of the film is reset in a step 13 and a step 14 is executed.
In, it is determined whether or not the switch Sw2 has changed to the ON state. If 100 ms elapses without the switch Sw2 changing to the ON state, it is determined in step 15 that the end of the film has been detected, and the end-of-film processing is executed. If it is determined in step 14 that the switch Sw2 has changed to the ON state, it is determined in step 16 whether the switch Sw2 has changed to the OFF state.If 100 ms elapses without the switch Sw2 changing to the OFF state, the step At 17 it is determined that the end of the film has been detected, and a film end process is executed.

If the switch Sw2 is changed to the OFF state in step 16, that is, if the (k + 1) th pulse is detected, the 1 ms timer is stopped in step 18 and the interruption of the interruption processing routine of FIG. It is forbidden. Then, in step 8, the switch Sw2 is set to O
The time from the determination of the FF state to the determination that the switch Sw2 is in the OFF state in Step 16 is:
It is measured by a counter in step 41 of FIG.
The period from the k-th OFF to the (k + 1) -th OFF of the switch Sw2 is indicated by a symbol in FIG. 9, and the time (Xms) becomes shorter as the winding speed of the motor 16 increases. Become.

When the measurement of the winding speed of the motor 16 is completed as described above, in step 19, the drive circuit of the wind motor 16 is short-circuited,
Is subjected to the first short-circuit brake. Steps
At 20, a short-circuit brake timer is started, and this timer is set to Y = A (ms) -X (ms) (1). Here, A is a constant, which is obtained, for example, by experiment.

In step 21, it is determined whether or not the one-frame detection switch Sw1 has been turned ON, that is, whether or not film winding has been completed, as indicated by the symbol p in FIG. The switch Sw1 is turned on when the brush of the encoder gear 8 (FIG. 3) comes into contact with the conductive portion 64 (FIG. 4).
In this state, steps 34 and subsequent steps are executed, and the reverse rotation brake is applied to the wind motor as described later.

On the other hand, if the switch Sw1 is not in the ON state in step 21, it is determined in step 22 whether Yms has elapsed. Steps 21 and 22 are repeated for Yms from the start of the timer in step 20, and during this time, the reverse rotation brake is applied to the wind motor 16 if the switch Sw1 is turned on.
23 and below are executed. That is, the short-circuit brake is at most Ym
s, and the time of this short-circuit braking becomes longer as the motor winding speed increases. The time during which the short-circuit brake is applied is indicated by a symbol in FIG.

In step 23, the timer (100m
s) is invoked. Then, in step 24, the wind motor is turned on, and in step 25, the Mms timer is started. If it is determined in step 26 that the switch Sw1 has changed to the ON state, steps 34 and subsequent steps are performed to apply a reverse rotation brake to the wind motor, but if the switch Sw1 has not changed to the ON state, in step 27
It is determined whether 100 ms has elapsed. Where step 23
If 100 ms has elapsed since the start of the timer in, it is determined that the end of the film has been detected, and the film end processing is executed. If 100 ms has not elapsed, it is determined in step 28 whether Mms has elapsed since the start of the timer in step 25, and steps 26 to 28 are repeated until Mms has elapsed.

If Mms has elapsed, the short-circuit brake is applied to the wind motor in step 29, and step
At 30 the Nms timer is started. If it is determined in step 31 that the switch Sw1 has changed to the ON state, steps 34 and subsequent steps are executed.If the switch Sw1 has not changed to the ON state, whether 100 ms has elapsed since the timer started in step 23 in step 32. It is determined whether or not. If 100
If ms has elapsed, it is determined that the end of the film has been detected, and the film end processing is executed.If 100 ms has not elapsed, in step 33, whether Nms has elapsed from the timer start in step 30 in step 33 No is determined, and steps 31 to 33 are repeated until Nms has elapsed.

Then, steps 24 to 33, wind motor 16
The motor circuit shown in FIG.
For a short time (OFF) for Nms.
Such a state is repeated temporally. This Mms and Nms
Is, for example, 3: 2.

When the film is wound up by one frame during the duty drive of the wind motor (sign), the switch Sw1 is turned on, and the process proceeds from step 26 or 31 to step 34, where the reverse rotation brake is applied to the wind motor 16. Can be In step 35, the Vms timer is started,
Step 36 is repeatedly executed until Vms elapses from the start of this timer. That is, the wind motor 16 can be reversely braked for Vms. This period is indicated by a symbol in FIG.

Next, at step 37, a second short-circuit brake is applied to the wind motor 16, and at step 38, the Wms timer is started. Step 39 is repeatedly executed until Wms elapses from the start of this timer, and the short-circuit brake is applied to the wind motor 16 for Wms. This period is indicated by a symbol in FIG.

With the above, the stop control of the wind motor 16 is completed, and the film winding process is completed. The motor 16 is in a free state during the period of FIG.

As described above, the present embodiment is configured such that the longer the winding speed of the wind motor 16, that is, the shorter the pulse interval of the switch Sw <b> 2 (the symbol in FIG. 9), the longer the time of the first short-circuit brake. ing. That is, the higher the film winding speed, the longer the short-circuit braking time (reference numeral in FIG. 9), and the film stops exactly at a predetermined position after winding one frame. Therefore, even if the film winding speed is increased, there is no possibility that the wind motor will overrun. Further, even if the amount of change in the motor speed increases due to a change in the voltage of the battery, which is the drive source of the wind motor, or a change in the motor load, the stop position of the film can be accurately determined.

In the above embodiment, the time of the first short-circuit brake
Yms is determined by the above equation (1), but is not limited to this, and may be any value as long as it increases as the film winding speed increases.

〔The invention's effect〕

As described above, according to the present invention, regardless of the speed of the wind motor, and even when the power supply voltage or the motor load fluctuates, the film can always be stopped at a predetermined position with a constant accuracy. Can be

[Brief description of the drawings]

1 is a block diagram showing a schematic configuration of a camera control circuit, FIG. 3 is a perspective view showing a film feeding mechanism, and FIG. 4 is a pattern of a wind pulse encoder. FIGS. 5 to 7 are flowcharts of a film winding process routine, FIG. 8 is a flowchart of a 1 ms interrupt processing routine, and FIG. 9 is a drive timing chart of a wind motor. 16… Wind motor 60 …… Encoder gear

Claims (1)

(57) [Claims] 1. A means for measuring a hoisting speed of a hoisting motor, a first deceleration control means for decelerating the hoisting motor by applying a short-circuit brake, and the first deceleration controlling means increases as the hoisting speed increases. After the brake time setting means for extending the operating time and the deceleration control of the hoist motor by the first deceleration control means, the second circuit for decelerating the hoist motor by temporally repeating conduction and short circuit of the motor circuit. If the winding of one frame of the film is completed while the first deceleration control means and the first deceleration control means are operating, the deceleration processing by the second deceleration control means is not executed and the winding motor is After the reverse brake has been applied and the hoisting speed has been reduced by the first deceleration control means, during the operation of the second deceleration control means, If Ilm is wound up by one frame, film winding motor stop control device is characterized in that a stop control means for applying a reverse brake to the hoist motor.