JPH10104701A - Film feeding controller for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film feeding controller for a camera which has a constitution simpler than a conventional one and high accuracy in a film stopping position and can feed a film at a high speed by obtaining a film position of less than one perforation, with the number of rotational amount pulses, on the basis of a previously set perforation position, so as to attain high speed drive up to the obtained film position and then, speed reduction control, so that a film moving speed just before the film is stopped becomes a fixed speed of 24-27ms. SOLUTION: A CPU 8 receives detection signals from a moving amount detecting sensor 4 by a perforation and a rotational amount detecting sensor 5 and obtains the film position of less than one perforation by the detection output of a rotational amount, based on the perforation at a fixed position, to execute high speed winding drive up to the obtained film position and then, the speed reduction control. Thus, a fixed speed section is formed and then, the speed of a motor is reduced to stop the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film feed control device, and more particularly, to a film feed control device improved so as to reduce variation in a film stop position in high-speed winding.

[0002]

2. Description of the Related Art One of the performance enhancements of a camera is to increase the winding frame speed during continuous shooting. However, when the winding speed is increased, the variation in the film stop position tends to increase. Therefore, the variation of the film frame interval falls within a predetermined range,
There is a demand for a film feeder capable of high-speed winding and having a simple mechanism. The conventional winding control method
There is a method based on one-rotation control and a method based on perforation control. The one-rotation control method has an advantage that the film can be fed at a high speed and the stopping accuracy of the film is high. On the other hand, it has a disadvantage that a mechanism is complicated and costs are increased, and a mechanical structure is large. On the other hand, the perforation control method is inexpensive and advantageous in terms of space, but is not suitable for high-speed feeding, and it is difficult to obtain an accuracy equivalent to one rotation control.

FIGS. 7A and 7B are diagrams for explaining an example of a one-rotation control device. FIG. 7A shows a control mechanism, and FIG. 7B shows the relationship between the film drive speed and time when the film is stopped. The one-turn control mechanism releases the release lever 2
After the second claw is separated from the one-rotation limiting plate 20 to enable rotation of one frame, the one-rotation limiting plate 20 makes one rotation and feeds one frame of film, and then the groove 20a of the one-rotation limiting plate 20 is fed. The claw 21a of the limit lever 21 is designed to jump in. The claw of the limit lever 21 is reliably inserted even at the time of high-speed frame feeding, and the stopping accuracy is also high. Therefore, as the control, it is sufficient to rotate the motor at a high speed and stop driving the motor when the claw of the limit lever 21 is fitted in the groove 20a of the one-rotation limit plate 20. Since it is not necessary to perform control for increasing the accuracy at the time of stopping, the hoisting control is completed quickly as a whole.

FIGS. 8A and 8B are diagrams for explaining an example of a perforation detection method. FIG. 8A shows a perforation detection control mechanism, and FIG. 8B shows the relationship between the film drive speed and time when the film is stopped. . Film 2
8 is provided with a sensor 27 for detecting perforation at a position facing the perforation 28a.
Is sent to the CPU 29. The CPU 29 controls the driving of the motor 26 for feeding the film by detecting the number of perforations 28a. This method controls the amount of film movement by detecting the amount of film movement based on the number of film perforations.When stopping the film, it is necessary to control the film at the time of stopping the film. However, there is a disadvantage that it is difficult to increase the speed of the camera.

[0005]

In recent years, cameras have been further downsized, and a large space cannot be secured.
Therefore, the problem is how to control at high speed and with high accuracy while adopting a perforation detection method which is difficult to achieve high speed, instead of one-rotation control. In order to solve this problem, the present inventor considered how to improve the accuracy at the time of stopping the film, and when the brake was finally applied as a preliminary experiment, the variation in the stop position of the film at the time of the stop was the target value. (For example, 0.2 mm) or less, the speed immediately before applying the brake was obtained.

FIG. 9 is a graph showing the results. The horizontal axis indicates the moving speed of the film, and the vertical axis indicates the variation width at the time of stopping. The moving speed of the film is actually indicated by the time required to move by one perforation, and this is called a pulse period. According to FIG. 9, the pulse period is 2
It can be seen that the variation is 0.2 mm or less at 5.4 ms / pulse. The value 25.4 at this time is a value obtained by averaging 20 data, and is actually 24 to
If it is 27 ms / pulse, the variation becomes 0.2 mm or less. Therefore, in order to suppress the variation at the time of stopping, it is sufficient that the speed immediately before the application of the brake is 24 to 27 ms / pulse.

An object of the present invention is to rotate a film position of less than one perforation based on a predetermined perforation position so that the film moving speed immediately before stopping the film becomes the above-mentioned constant speed of 24-27 ms. It is determined by the number of pulses and driven to that position at high speed.
An object of the present invention is to provide a film feed control device for a camera capable of performing a high-speed film feed with a simpler configuration than in the prior art and a high accuracy of the film stop position by performing deceleration control thereafter.

[0008]

According to the present invention, there is provided a film winding control apparatus for a camera, comprising:
A film feed control device for a camera that performs film deceleration control by detecting the position of a specific perforation in one frame and stops the film at the next frame position. The position is set to be the film deceleration control start position. The present invention, in the above configuration, comprising a perforation detection means for detecting the perforation of the film, a rotation amount detection means for detecting the rotation amount of the motor for feeding the film, and a motor drive circuit for driving and controlling the motor, The perforation detection means detects a predetermined number of perforations indicating one frame, and the rotation amount detection means determines the number of pulses indicating the motor rotation amount during the predetermined number of perforations. By calculating the number of pulses indicating the motor rotation amount of less than one perforation number,
After counting the number of pulses of the calculated motor rotation amount from the predetermined perforation, the motor drive circuit starts deceleration control. Further, the film feeding for one frame in the present invention is performed by winding at a high speed drive, applying a brake from a film position having less than one perforation, applying a brake for a fixed time, winding and stopping at a low speed drive at a constant speed. It is configured to perform control to apply the brake again and stop immediately before the position to be performed. Further, the perforation position immediately before performing the deceleration control in the present invention can be the seventh perforation when one frame is set to 8 perforations.

[0009]

According to the above configuration, high-speed winding during continuous shooting can be accurately performed with a simple configuration.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram for explaining a deceleration control method of a film feed control device for a camera according to the present invention. FIG. 1A schematically shows a change in speed at the time of deceleration / stop, in which the horizontal axis represents time and the vertical axis represents speed. The film is wound up at a high speed, and a brake is applied with the film length a of less than 1 perforation based on the 7th perforation, in this example, the 0.5th perforation as the deceleration control start position. In this way, a constant winding speed section is provided, and thereafter, control is performed so as to detect the last eighth perforation and apply a brake for stopping.

As a matter of course, in order to realize high-speed continuous shooting, apply a brake immediately before the film stop position.
It is better to make the time for high-speed driving as long as possible. Therefore, in this embodiment, after the seventh perforation is detected, after a predetermined number of perforations (less than one), deceleration is started. In this embodiment, the film length a of less than 1 perforation is set to 0.5 perforation, but this value is set so that the time of one perforation becomes 24 to 27 ms as shown in FIG. This is used as an appropriate number of perforations for speed control. Therefore, the time for one perforation is 24 with a value other than 0.5 perforation.
Other values may be used as long as a constant speed section of up to 27 ms can be created.

FIG. 2 is a diagram schematically showing an embodiment of a film feed control device for a camera according to the present invention. A movement amount detection sensor 4 for detecting the movement amount of the film by detecting the perforation 3 of the film 2 and a rotation amount detection sensor for detecting the rotation amount of a gear train 9 connected to a motor 6 for feeding the film. A sensor 5 is provided. The rotation amount detecting sensor 5 can obtain the rotation amount of the motor by detecting the rotation number of the rotating plate 7 to which the rotation amount of the gear train 9 is transmitted. Movement amount detection sensor 4
And the detection signal of the rotation amount detection sensor 5 is sent to the CPU 8. The CPU 8 performs an operation for deceleration control, sends a brake signal and a stop signal to the motor 6, and feeds the film accurately for one frame.

FIG. 3 is a diagram showing output waveforms of two sensors for detecting a moving amount and a film rotating amount. Has a sensor 5 for detecting the amount of rotation corresponding to the perforation.
3 shows the output waveform. One output waveform is obtained for one perforation. The movement amount is 8 for one frame
This is perforation, and eight signals are obtained. In the case of controlling only with this signal, it is necessary to determine the brake timing with eight signals or to control at a constant speed, so that it is difficult to obtain accuracy. The first frame and 3
The output waveform of the motor rotation amount of the sixth frame is shown. When the rotation amount of the motor is compared with the movement amount detection signal, more pulse outputs are obtained, and about 200 pulses can be obtained for one frame. The number of output pulses first frame and N _1, the number of output pulses 36 th frame when the N _2, is the relation of N _1> N _2. This is because, as the film is wound, the diameter of the winding increases with the thickness of the film itself, and the amount of rotation decreases as the number of shot frames increases. For example, the first frame is 2
For the 15th and 36th frames, 165 outputs are obtained.

From the output waveform, it can be understood that finer control can be performed between perforations by using a rotation amount output waveform having a large number of output signals. However, the number of rotation output pulses of each frame is not constant with respect to the amount of film movement, and the number of rotation output pulses differs for each frame. This means that, for example, the brake is decelerated with the 100th pulse output from the start of the hoisting drive, decelerated, becomes free with the 150th pulse output, and
Apply the brake to stop at the 3rd pulse and stop,
With such control using a fixed value, the accuracy at the time of stopping cannot be guaranteed. Therefore, in the present invention, deceleration control is performed by using both the movement amount detection output by perforation and the rotation amount output waveform.

FIG. 4 is a diagram for explaining a method of calculating the deceleration control start position using the relationship between the displacement detection output by perforation and the rotation output waveform. The amount of film movement in one frame is 8 perforations, and the CPU 8 counts output pulses corresponding to the rotation amount of several perforations. In this example, the outputs of four perforations from the second to the sixth after the driving is started are counted. As a result, a rotation amount corresponding to a predetermined number of perforations is obtained for each frame. Since the number of rotation amount pulses is eight in four perforations, the number of two rotation pulses per perforation can be calculated.

In the example shown in FIG. 1, the timing of the deceleration control according to the present invention is set at 0.1 after detection of the seventh perforation.
Since the deceleration control is started at the fifth perforation, the deceleration control start position is the first rotation amount pulse number from the seventh perforation. The deceleration control is started from a position less than one perforation based on the predetermined perforation position in this way, and the film position less than one perforation is obtained by the number of rotation pulses to obtain the film position from the first frame to the last frame. Regardless of the frame, the deceleration control start position can be set to the same position.

FIG. 5 is a diagram showing the relationship between the output waveform of the amount of rotation, the drive signal of the motor, and the brake signal. When the motor drive signal is at the H level and the brake signal is at the L level, the motor is rotationally driven. Conversely, when the motor drive signal is at the L level and the brake signal is at the H level, the motor is decelerated. State. When the 7.5th perforation is detected by the pulse indicating the rotation amount, the brake is applied, and thereafter, the control is shifted to the constant speed drive control. In the constant-speed driving, the pulse width of the motor drive signal is controlled so that the output of the motor rotation amount outputs a predetermined pulse, thereby controlling the target constant speed of 24 to 27 ms / pulse. Thereafter, the motor is decelerated by detecting the eighth perforation and the motor stops.

FIG. 6 is a graph showing the actual interval between frames when the film is wound up by the film feed control device of the camera according to the present invention. It shows how it has changed. It can be understood that the variation width of the frame interval is improved with respect to the high-speed winding drive.

[0019]

As described above, according to the present invention, a film position having a number of perforations less than one from a predetermined perforation is set as a film deceleration control start position. A moving amount detecting means for detecting a perforation of the film; a rotating amount detecting means for detecting a rotating amount of a motor for feeding the film; and a motor driving circuit for driving the motor. By detecting a predetermined number of perforations out of the number of perforations indicating the number of minutes and detecting the number of pulses indicating the motor rotation amount during the predetermined number of perforations by the rotation amount detecting means, the number of perforations is determined. After calculating the number of pulses indicating less than one motor rotation amount, counting the number of pulses of this motor rotation amount, the motor drive circuit starts deceleration control. Therefore, since the deceleration control can be performed from an arbitrary position of the film between the perforations instead of the perforation position for each frame, the film winding constant speed section before stopping the film can be set to the target predetermined speed, and each frame can be controlled. On the other hand, the film can be stopped accurately. In particular, in order to realize high-speed winding during continuous shooting, it is required that the time for high-speed driving be as long as possible. According to the present invention, less than one perforation is performed from the perforation immediately before the last perforation of one frame. Can be driven at high speed to the perforated film position. Then, since the deceleration control is performed thereafter to set the film constant speed section to a predetermined speed, it is possible to realize high-speed winding with a simple structure and high winding accuracy of each frame.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a deceleration control method of a film feed control device for a camera according to the present invention.

FIG. 2 is a diagram schematically showing an embodiment of a film feed control device for a camera according to the present invention.

FIG. 3 is a diagram showing output waveforms of two sensors for detecting a moving amount and a film rotation amount.

FIG. 4 is a diagram for explaining a calculation method of a deceleration control start position using a relationship between a movement amount detection output by perforation and a rotation amount output waveform.

FIG. 5 is a diagram showing a relationship between an output waveform of a rotation amount, a motor drive signal, and a brake signal.

FIG. 6 is a graph showing measured actual frame intervals when the film is wound up by the film feed control device of the camera according to the present invention.

FIG. 7 is a diagram for explaining an example of a one-rotation control device;
(A) shows the control mechanism, and (b) shows the relationship between the film drive speed and time when the film is stopped.

FIGS. 8A and 8B are diagrams for explaining an example of a perforation detection method, in which FIG. 8A shows a perforation detection control mechanism, and FIG. 8B shows a relationship between a film driving speed and time when the film is stopped.

FIG. 9 is a graph showing a relationship between a moving speed of a film and a variation width at the time of stop.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Patrone 2 ... Film 3 ... Perforation 4 ... Sensor for detection of movement amount 5 ... Sensor for detection of rotation amount 6 ... Motor 7 ... Rotating plate 8 ... CPU (control circuit) 9 ... Gear train

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[Procedure amendment]

[Submission date] January 28, 1997

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Claims (4)

[Claims] 1. A film feed control device for a camera, which controls a film deceleration by detecting a position of a specific perforation in one frame, and stops the film at the next frame position. 1
A film feed control device for a camera, wherein less than the number of film positions are set as film deceleration control start positions. 2. A perforation detecting means for detecting perforation of a film, a rotation amount detecting means for detecting a rotation amount of a motor for feeding the film, and a motor drive circuit for driving and controlling the motor, The detecting means detects a predetermined number of perforations indicating one frame, and the rotation amount detecting means detects the number of pulses indicating the motor rotation amount during the predetermined number of perforations. By calculating the number of pulses indicating the motor rotation amount less than one perforation number, counting the number of pulses of the calculated motor rotation amount from the predetermined perforation, starting the deceleration control by the motor drive circuit 2. The camera according to claim 1, wherein Film feed control device. 3. The film feeding for one frame is performed by winding at a high speed, applying a brake from a film position having less than one perforation, applying a brake for a certain time, and winding at a low speed at a constant speed. 3. The film feed control device for a camera according to claim 2, wherein a control is performed to apply a brake again and stop immediately before the stop position. 4. The film feed control device for a camera according to claim 2, wherein the perforation position immediately before the deceleration control is performed is the seventh perforation when one frame corresponds to eight perforations. .