JPH0256530A - Automatic rewinding camera - Google Patents

Abstract

PURPOSE:To accurately detect the removal of the slack and to set a timer time for deciding the end of rewinding by providing a timer which starts clocking operation when the movement stop of a film is detected. CONSTITUTION:When a film which is already exposed is wound up to its end, an end detecting means sends an end detection signal to a CPU 7. In automatic rewinding mode, the CPU 7 starts rotating a rewinding motor 2 at the point of time and starts rewinding the film. At this time, the majority of the film in a cartridge is drawn out, so the film has no slack and a printed board 5 outputs pulses at equal intervals. The CPU 7 judges that the rewinding is finished when the pulses are not outputted for the specific timer time. In this case, the timer time varies according to whether or not there is the slack. Consequently, even when the period of the pulses is unstable, the film is rewound without being stopped halfway.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic rewind camera that rewinds film using a motor.

(Prior art) Such a camera is disclosed in Japanese Patent Application Laid-Open No. 60-52834 (
USP4679926), Japanese Patent Publication No. 62-157020
listed in the number.

In the camera described in Japanese Patent Application Laid-Open No. 60-52.834,
In order to take up slack in the film during rewinding, the timer time for determining the end of rewinding is switched before and after the detection signal of the film movement detecting means is output.

In the camera described in JP-A-62-157020,
If a predetermined number of pulses that are generated in response to film movement are not generated within a predetermined period of time from the start of rewinding, it is determined that a rewinding error has occurred. Rewinding is determined to be complete when no input is received (Problem to be Solved by the Invention) The prior art, particularly the camera described in Japanese Patent Laid-Open No. 60-52834, had the following problem.

At the beginning of rewinding, as shown in FIG. 8, the film may be sagging, and the upper and lower films may be in close contact with each other at part a due to moisture or the like. When the cartridge rewinding shaft rotates, the film outside the cartridge is initially stopped, but once the slack is removed to a certain extent, the contact area a
The film outside the cartridge is moved. but,
Since the adhesion is weak, the films above and below part a are immediately peeled off, and the slack is further removed. At this time, the film outside the cartridge is stopped again. By repeating this, the slack is removed.

FIG. 9 is a diagram showing the moving speed of the film outside the cartridge. In this way, the film moves intermittently. If the interval time t of this intermittent movement is longer than the timer time for determining the end of rewinding, a problem arises in that rewinding ends at that point.

Normally, the timer time for determining the end of the film until the slack is removed is set to a relatively long time, and the timer time after the completion of the slack removal is set to be short, so there is a high possibility that the time t will exceed that time.

This invention was made to deal with the above-mentioned circumstances,
To provide an automatic rewinding camera that can accurately detect that slack has been removed and can appropriately set a timer time for determining the end of rewinding accordingly.

(Means and effects for solving the problems) The automatic rewind camera according to the present invention includes a rewind motor, a pulse generator that generates a pulse when film movement is detected, and a pulse generator that generates a pulse when the film movement is detected. It is equipped with a control circuit that controls the drive, and the control circuit has a timer that starts timing operation when it detects that the film has stopped moving, and a circuit that stops the drive of the rewind motor when this timer measures a predetermined time. However, this predetermined time is switched to a shorter time when it is detected that the film is moving by a predetermined amount and at a predetermined speed.

(Embodiments) Hereinafter, embodiments of the automatic rewind camera according to the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the first embodiment. A rewind motor 2 is connected to the shaft of the film cartridge 1 via a gear train (not shown).
The shafts of are engaged. As a result, the film is rewound into the cartridge 1 by the rotation of the rewind motor 2.

The film is wound on the spool 4 by a drive system (not shown).
This is done by rotating the . The winding spool 4 may be rotated automatically or manually.

The teeth of the driven sprocket 3 are fitted into the perforations of the film, and the driven sprocket 3 rotates in accordance with the movement of the film. The rotation of the driven sprocket 3 is transmitted to the contact piece 6 on the disk-shaped printed circuit board 5 via a mechanism (not shown).

As shown in FIG. 2, a conductive pattern is printed on the printed circuit board 5 at regular intervals along its circumference.

Therefore, as the contact piece 6 slides and rotates on the printed circuit board 5 in conjunction with the rotation of the sprocket 3, a pulse is generated from the printed circuit board 5 every time the film moves a certain distance.

This pulse is input to the CPU 7, and the CPU 7 controls the rewind motor 2 via the driver 8.

A rewind switch 9 is also connected to the CPU 7 for forcibly starting rewinding in the middle of the film.

Next, the operation of the first embodiment will be explained.

The photographed film is transferred to the spool 4 by a winding mechanism (not shown).
When the film is wound up to the end, a well-known end detection means sends an end detection signal to the CPU.
7 can be conveyed.

In the automatic rewind mode, the CPU 7 starts rotating the rewind motor 2 at that point and starts rewinding. At this time, since most of the film in the cartridge has been stretched out, there is no slack, and the printed circuit board 5 outputs equally spaced pulses as shown in FIG.

The CPU 7 determines that rewinding has ended when this pulse is not output for a predetermined timer period or longer. However, this timer time varies depending on the presence or absence of slack. That is, the fifth
As explained in the flowchart in the figure, it is determined that slack removal is complete at time p when n pulse changes (rising and falling) are detected, and the timer time is changed from 5 seconds to 0.5 seconds. Switch. Therefore, when all the films are rewound, the sprocket 3 stops rotating, and the printed circuit board 5 no longer outputs pulses, the CPU 7 starts the rewind motor 2 to rotate 0.5 seconds after the last pulse change. and end rewinding. Therefore, the tongue can be left outside the cassette without rewinding the entire film into the cassette.

In the manual rewind mode in which the film is forcibly rewound up to an intermediate frame, the operator presses the rewind switch 9 shown in FIG. The CPU 7 receives the signal from the switch 9 and starts rotating the rewind motor 2. Here, if the film is slack in the cartridge, the pulses generated from the printed circuit board 6 will be as shown in FIG.

The period A after the rewind motor is turned on is a period in which the amount of rotation of the shaft of the cartridge 1 is not directly proportional to the amount of film movement due to slack and catch in the cartridge 1, as described above. Therefore, during this period A, the pulse width and pulse period are irregular.

Then, when the slack is removed, as shown in period B,
The rotation of the shaft of cartridge 1 and the movement of the film are directly proportional. During this period, pulses of approximately constant pulse width are periodically generated, and extremely long pulses are not generated. After the slack has been removed, the rewind motor 9 must be stopped when the pulse generation stops due to the end of the film during rewinding. The film end is detected when there is no next pulse change even after a predetermined timer time (pulse standby time) has elapsed since the previous pulse change.

Further, even before the slack is removed, rewinding may not be possible due to an abnormality in the cartridge 1, so if no pulse is generated for a certain period of time, the rotation of the rewind motor 9 must be stopped.

By the way, before the slack is removed, pulses may not be generated for a relatively long time. In such a case, it would be inconvenient to determine that the film has ended, so it is preferable to set the timer time in this case to a relatively long value t1. This value should be greater than the longest pulse interval produced when the film is at maximum slack.

However, if the timer time remains the same even after the slack has been removed, the rewind motor 9 will continue to be driven for a long time even when the film has truly ended, which is a waste of battery power and time. , it cannot be used when you want to leave the tongue of the film and wind it onto Patrone 1. Therefore, in this case, the timer time is set to a relatively short value t2(
tl>t2).

The timing of switching the timer time based on the complete removal of this slack is determined based on the periodicity of the pulse. That is, the interval between pulse changes continues n times for a predetermined time t3.
At a certain point in time, it is determined that the slack has been completely removed.

As a result, since period A includes a pulse longer than t3, it is not determined that slack has been removed.

Therefore, the pulse waiting time until the motor stops remains tl.

However, in period B, when periodic pulses are generated and the intervals between zero pulse changes are all less than t3, the pulse waiting time is shortened to t2, and the motor is stopped immediately at the end of the film. .

FIG. 5 shows a flowchart of the CPU 7.

When rewinding is started, the rotation of the motor 9 is started in step 10, and the timer is reset and started in step 12.

In step 14, it is determined whether there is a pulse change.

If there is no pulse change, i.e. the film is not moving, then in step 16 the timer value is tl (-5
seconds) or more. If the timer value is not 5 seconds or more, the process returns to step 14 and the presence or absence of a pulse change is determined again. If the timer value is 5 seconds or more, it is determined that the rewinding is abnormal, and the rotation of the motor 9 is stopped in step 18, and the process ends.

If a pulse change occurs in step 14, step 2
0, the timer value is t3. (-0, 2 seconds) or less is determined. If the timer value is not less than 0.2 seconds, the timer is set to N-0 in step 22, and the timer is reset and started again in step 12. The timer value is 0.2
If it is less than seconds, N is increased by 1 in step 24.

In step 26, it is determined whether N is equal to n (predetermined number). If N is not equal to n, the timer is reset and started again in step 12.

If N is equal to n, it is determined that the slack has been completely removed, and in step 28, the timer is reset and started again. At step 30, it is determined whether there is a pulse change. If there is a pulse change, the timer is reset and started again in step 28. If there is no pulse change, the timer value is set to t2 (-0
, 5 seconds) or more. If the timer value is not 0.5 seconds or more, the process returns to step 30 and the presence or absence of a pulse change is determined again. If the timer value is 0.5 seconds or more, it is assumed that rewinding has ended, and the rotation of the motor is stopped in step 34 to end the rewinding. Based on the periodicity, it is possible to accurately detect that the slack has been completely removed. Before this detection, the pulse waiting time for determining the film end is set relatively long, and after this detection, the pulse waiting time for determining the film end is set relatively long. By setting it short, even when slack remains, the rotation of the motor can be stopped in the case of abnormal rewinding, and the rotation of the motor can be stopped immediately in the case of a true film end.

Next, a second embodiment will be described. FIG. 6 shows a schematic configuration. Here, instead of the printed circuit board 5 and contact piece 6 as the pulse generating means of the first embodiment, a photointerrupter 11 and a light shielding plate 10 having slits provided at equal intervals in the circumferential direction are used. Further, a control circuit 12 is used instead of the CPU 7. The other configurations are the same as in the first embodiment.

FIG. 7 is a circuit diagram of the control circuit 12. The pulse signal generated by turning on/off the photointerrupter 11 is
D-type flip-flops 14, 15.1 connected in series
6, and a differential pulse is output at both the rising and falling edges of the pulse. The oscillator (O6C) 27 is a clock or generator that supplies reference clocks to flip-flops and counters.

The counter 32 is tl-5 seconds, t2-0.5 seconds.

Output terminal CI after three types of timer times from t3 to 0.2 seconds
, C2, C3 to output an "H" level signal, which is reset by the output of the OR gate 22, and the oscillator 2
Count the output of 7.

Among the counter outputs CI, C2, and C3, C3, which is used for comparing pulse periods for detecting slack removal, is connected to the clock terminal CLK and reset terminal R of the counter 33 through logic gates 23, 24; 25, and 26, respectively. is entered.

On the other hand, the counter outputs C1 and C2 are AND gate 35.3
6, one of them is selected and supplied to the input terminal R of the SR type flip-flop 31. The AND gates 35 and 36 are controlled by the output Q of the S-R type flip-flop 38, and the output of the flip-flop 38 is "L".
If the level is "H", the output Ct is selected, and if the level is "H", the output C2 is selected.

The counter 33 counts the number of pulse changes with a period of t3 or less, and when counted n times, the output terminal D1
A signal at the "H" level is input to the input terminal S of the flip-flop 38.

The motor driver 13 drives the rewinding motor 2 when the output signal Q of the flip-flop 31 is at the "H" level, and when the output signal Q of the flip-flop 31 is at the "L" level.
Stop at level.

The operation of the second embodiment will be explained. A case will be explained in which there is slack in the film and a pulse as shown in FIG. 4 is generated.

When the rewind switch 9 is turned on, the
Flip-flop 31 is set. Thereby, the motor driver 13 starts driving the rewind motor 2.

At the same time, the reset of the counters 32 and 33 is released, and the clock from the oscillator 27 can be counted.

When the film moves due to the rotation of the rewind motor 2, a pulse is generated from the photointerrupter 11 and differentiated by the flip-flops 14, 15, and 16. As a result, a differential pulse is input to the OR gate 21 every time the pulse changes, and immediately after that, a differential pulse is also input to the OR gate 22.

The output pulse of OR gate 21 is supplied to AND gate 23. When the output C3 of the counter 32 is at the "L" level, that is, when the timer elapsed time is less than or equal to t3 (-0, 2 seconds), the AND gate 23 is non-conductive and the signal is not transmitted further.

On the other hand 1. Since the A N D gate 26 is made conductive by the inverted signal of the output C3 of the counter 32 and passes the output pulse of the OR gate 21, the counter 33 counts up.

Furthermore, the pulse output from the OR gate 22 resets the counter 32. Therefore, counter 32 counts up the clock from oscillator 27 again.

When the value of the counter 33 reaches the predetermined value n, the output DI becomes “
It becomes "H" level and sets the flip-flop 38.Until then, the output C1 of the counter 32 was inputted to the flip-flop 31 by the logic gate 34, 35, 36, 37, but the output DI becomes "H" level. As a result, the output C2 is input to the flip-flop 31.

In period A in FIG. 4, pulses with an interval of 0.2 seconds or more are also generated. However, in this case, the differential pulse from the OR gate 21 is applied to the AND gate 23 and the OR gate 2 because the output C3 of the counter 32 is at the "H" level.
4, and the counter 33 is reset. That is,
Clear the numbers that have been counted up to that point.

If the generation of pulses from the photoinkrater 11 stops before time p in FIG. 4, the counter 32 continues to count up, and after 5 seconds, the output C1 of the counter
becomes “H” level. The output D1 of the counter 33 is “L”
Because of the level, the flip-flop 31 is reset via the gates 435 and 37, and the rotation of the motor 2 is stopped.

On the other hand, all n consecutive pulse changes are 0. If it is less than 2 seconds, the flip-flop 38 is reset at time p in FIG.
The output C2 of 2 is input to the flip-flop 31. When rewinding is completed and no pulse is output from the photointerrupter 11, the counter 32 continues counting up, and after t2 - 0.5 seconds, the output C2 becomes "H" level, and the signal is passed to the flip-flop 31. reset and
The rotation of the rewind motor 2 is stopped.

In this way, the control circuit 12 of the second embodiment can also realize the same operation as the CPU 7 of the first embodiment.

(Effects of the Invention) As explained above, according to the present invention, even if the film becomes sticky due to moisture or the like and the cycle of unwinding and the pulses generated accordingly are unstable, rewinding can be stopped midway. Also, since the end of the film can be determined in a short time when rewinding, there is no wasted time or battery consumption, and the film can be rewound without leaving the edge of the film. You can also keep it.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing a first embodiment of an automatic rewind camera according to the present invention, FIG. 2 is a diagram showing a printed circuit board, and FIG.
The figure is a signal waveform diagram during automatic rewinding, Figure 4 is a signal waveform diagram during midway rewinding, Figure 5 is a flowchart showing the operation of the first embodiment, and Figure 6 is an outline of the fourth embodiment. 7 is a circuit diagram of the control circuit, FIG. 8 is a diagram showing film slack, and FIG. 9 is a diagram showing rewinding in that case. 2... Rewinding motor, 3... Driven sprocket, 5
...Printed circuit board, 6...Touch piece, 7...CPU. 8... Rewind switch. Applicant's representative Patent attorney Atsushi Tsuboi

Claims (1)

[Claims] The actuator means for rewinding the film, the means for detecting the movement of the film, and the control means for controlling the drive of the actuator means based on the output of the detecting means, the control means being configured such that the detecting means detects the movement of the film. It has a timer circuit that starts a timing operation when it detects a stoppage, and a stop circuit that stops driving the actuator means when the timer circuit measures a predetermined time. Automatic rewind camera that switches to a short time when it detects that you are moving at a high speed.