JPH0736088A - Film rewinding device - Google Patents

Abstract

PURPOSE:To accurately detect the end of rewinding a film even in a system for detecting the end of rewinding the film by a sprocket. CONSTITUTION:A pulse signal is outputted cooperatively with the sprocket 10 by a pulse signal output part 20, a time interval between each pulse signal is counted by a timer part 31, and in the case the interval exceeds a prescribed interval, it is judged that rewinding the film is ended. The number of film sheets is counted by a 1st counter part 32 based on each outputted pulse signal, and in the case the counted number reaches a prescribed value, counting is newly started by a 2nd counter part 33, and the end of rewinding is detected when the number reaches a prescribed value. And a film rewinding motor 41 is stopped by a stoppage control part 34 based on the detection result by the timer part 31, or the 2nd counter part 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film rewinding device for rewinding a film loaded in a camera body.

[0002]

2. Description of the Related Art In recent years, a camera that automatically carries out a film feeding operation by a motor has become popular.

This type of camera is composed of a film winding mechanism, a film rewinding mechanism, a motor control circuit, and the like. This motor control circuit is controlled by a detection signal (pulse signal) of the film feeding detection mechanism. It
It is important to output this detection signal by following the movement amount of the film.

For example, Japanese Unexamined Patent Publication No. 58-83827 discloses a case where a perforation is directly detected by a photo coupler and a case where a perforation is detected by a mechanical switch linked to a sprocket.

As the former optically detecting mechanism, there is known a mechanism for optically detecting that the end portion of the film has passed a specific position. As this detection mechanism,
For example, there is a method in which the movement of the film is directly detected by a photoelectric element facing the perforation and a pulse signal is generated. Although this method can accurately detect the end of rewinding, it has a drawback in that the apparatus configuration becomes expensive.

Therefore, the latter mechanism for detecting using a mechanical switch is widely adopted, and the method of detecting the movement of the perforation of the film by the movement of the sprocket rotating by fitting to the perforation is generally used. Is.

[0007]

However, although this method has the advantage that it can be constructed at low cost, it has the drawback of lacking reliability.

The reason for this will be described with reference to FIG. The sprocket rotates following the film movement, and along with this, a pulse signal that alternately switches between the “H” level and the “L” level is output. Now, at the time t, if the rewinding of the film is finished, the rotation of the sprocket is stopped by this, so that a constant "H" level is output as shown in FIG. 4A, or As shown in FIG. 4B, a constant "L" level is output.

However, when the rewinding is completed, the sprocket separates from the perforation, but the rotation stop position of the sprocket at this time is controlled by chance, and the rotary shaft rotated by the sprocket maintains its final position. Will continue to do. This rotary shaft is interlocked with a switch member for generating a pulse, and in extreme cases, it may stop at a delicate position where the pulse switches between “H” and “L”. In such a case, as shown in (c) of FIG. 4, due to the vibration of the transmission system or the like, fine pulse signals of "H" and "L" are continuously output. The fine "H", which is output like this,
The "L" pulse signal is input to the motor control circuit as a false signal as if the film feeding continues. Therefore, although the film is completely rewound in the cartridge, the motor continues to rotate and cannot be stopped.

The present invention has been made to solve such a problem, and an object thereof is to accurately detect the completion of film winding even in a system in which the completion of film rewinding is detected by a sprocket. An object is to provide a rewinding device.

[0011]

Therefore, a film rewinding device according to the present invention is a film rewinding device for rewinding a film loaded in a camera body, and a film driving device for rewinding the film and forming the film on the film. A sprocket that has a plurality of protruding pins that fit with each of the perforations and that rotates by following the amount of movement of this film; pulse signal output means that outputs a pulse signal in conjunction with the rotation of the sprocket; and a pulse signal From the pulse signal means, a first end detecting means for measuring the time interval of each pulse signal output from the output means and judging that the rewinding of the film is completed when the time interval exceeds a predetermined time interval. Counting means for counting the number of wound films based on the pulse signal generated,
The second end detection means, which is activated when the number counted by the counting means reaches a predetermined value and detects the completion of the rewinding of the film, and the first end detection means or the second end detection means. And a stop control means for stopping the rewinding operation by the film driving means based on the detection result.

Further, the second end detecting means is constituted by the second counting means which newly starts counting based on the pulse signal outputted from the pulse signal outputting means, or the counting number by the counting means is changed. It may be configured by a timer means for starting timekeeping when it reaches a predetermined value.

[0013]

The film rewinding device according to the present invention determines the completion of film rewinding by the two judgment systems described later.

First, when the film is rewound by the film driving means, a pulse is output from the pulse signal output means along with the rewinding. This pulse is
A predetermined number of pulses is output for each film (one frame), and the counting means counts the number of wound films (the number of frames) based on the output pulse number. As the rewind continues, the sprocket eventually reaches a position where the film is not perforated and its rotation stops. Therefore, the pulse signal output means stops outputting the pulse signal.

Therefore, the first end detecting means constituting one of the judging systems judges that the rewinding of the film is completed because the next pulse is not output within a predetermined time, and this result is stopped and controlled. Communicate to the means. The stop control means that has received this detection result stops the rewinding operation by the film drive means. By this processing, the completion of the normal film rewinding operation is detected.

The second judgment system which constitutes the other judgment system
In the end detection means of (1), it is started when the number of counts by the counting means reaches a predetermined value (for example, a value in which all the number of films (number of frames) is wound up), and the counting is continued, or , Start timing. Then, after the detection result of the second end detection means reaches a value sufficient for the film to be completely wound into the cartridge, this result is transmitted to the stop control means. In addition,
At this time, if the sprocket stops at a halfway position,
Even if the pulse signal is continuously output from the pulse signal output means, the completion of the winding is detected as a result of measurement by the second end detection means.

In this way, by judging the end of the rewinding by the two judging systems, it is possible to surely detect the completion of the winding of the film even when the above-mentioned trouble occurs.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The structure of the film rewinding device provided in the camera body will be described with reference to FIGS. 1 and 2. This device includes a sprocket 10 that rotates following the movement amount of the film 1, a pulse signal output unit 20 that outputs a pulse signal in synchronization with the rotation of the sprocket 10, a microcomputer unit 30 that performs various controls and measurements, and A motor control unit 40 that controls the drive of a winding / rewinding motor (hereinafter, simply referred to as a motor) 41 for winding the film 1 is provided.

The sprocket 10 is provided with a large number of projecting pins 11 which are fitted with the perforations 2 of the film 1 in a radial pattern, and is rotated by the moving perforations 2 when the film 1 is fed. Has become.

The pulse signal output section 20 is a SW contact piece 2 which rotates integrally with the sprocket 10 via a shaft 21.
2 and a ring-shaped conductor pattern 2 fixed to the support plate 24
S, which is equipped with 3 and rotates with the sprocket 10.
By the W contact piece 22, the conductor pattern 23 is short-circuited and released, and by this operation, L (Low), H (High)
The pulse signal of is output.

The microcomputer unit 30 includes a pulse signal output unit 2
A pulse signal output from 0 is applied, and the timer unit 31 and the first counter 3 are activated based on the pulse signal.
2, a second counter 33 and a stop controller 34 are provided.

The timer section 31 is started by receiving the pulse signal input to the microcomputer section 30, measures the time until the next pulse signal is input, and the next pulse signal is output within a predetermined time. It detects whether or not it is output. When the next pulse signal is input within this predetermined time, this timer is reset and the time measurement until the output of the next pulse signal is started again.

The first counter 32 is interlocked with a display unit (not shown) for displaying the current number of films, and based on the pulse signal input to the microcomputer unit 30, as the film 1 is wound, the first counter 32 advances. , The number of remaining films is sequentially subtracted.

The second counter 33 is input to the microcomputer unit 30 at the time when the count number of the first counter 32 becomes, for example, "-2", that is, after all the film 1 having been photographed has been wound up. Counting is started based on the pulse signal. This is because even when the count number of the first counter 32 becomes "-2", when the film 1 is loaded,
The film arbitrarily drawn by the user may remain on the film running surface or the winding shaft, and the number of films is sequentially added as the film is wound. Further, as will be described later, when the sprocket 10 stops rotating, the pulse signal output unit 20 outputs fine pulse signals of “L” and “H” due to the positional relationship between the SW contact piece 22 and the conductor pattern 23. In this case (see FIG. 4C), the number of wound films is sequentially added based on this pulse signal.

The stop control unit 34 has a function of instructing the motor control unit 40 to stop the motor 41, and operates based on the judgment criteria of two systems.

One of the systems is the timer unit 31,
The case where it is determined that the next pulse signal is not output from the pulse signal output unit 20 within a predetermined time, and the other system is the case where the count number of the second counter 33 exceeds the predetermined value. . In the former case, when the rotation of the sprocket 10 is stopped, the SW contact piece 22 is stopped at either the “L” region or the “H” region of the conductor pattern 23, and as a result, the pulse signal output unit 20 keeps a constant value. This is a state in which the level signal (see (a) and (b) in FIG. 4) is continuously output. In the latter case, the SW contact piece 22 is stopped at the boundary between the “L” area and the “H” area of the conductor pattern 23, and fine pulse signals of “L” and “H” (see FIG. 4). (See (c)) is output.

In each of these two cases, the film 1 is completely rewound, and the rewinding completion signal is given to the motor controller 40 to stop the rotation of the motor 41.

Here, the processing operation of the film rewinding device thus constructed will be described with reference to the flowchart of FIG.

First, when the rewinding of the film 1 is requested (# 100), the count number of the second counter section 32 is reset to "0"(# 102).

Next, a signal for rewinding control is sent to the motor controller 40 (# 104). As a result, the motor 41 starts rewinding rotation, and the film 1 is transported in the rewinding direction. Further, the timer unit 31 is initialized and the time interval of each pulse signal is started (# 106).

Next, the timer unit 31 measures whether or not the pulse signal to be output next is detected within a predetermined time ("N" in # 108, "N" in # 110). If the next pulse signal is output within the specified time (#
110 is “N”, # 108 is “Y”), and it is determined whether or not the count number of the first counter unit 32 is equal to a predetermined value (# 112). This predetermined value is, in addition to the above-mentioned "-2" (the value after all the film 1 that has been photographed has been wound up),
It may be “−1”, “0”, “1”, etc., and is not particularly limited.

When the count number of the first counter section 32 is not a predetermined value ("N" in # 112), the count number of the first counter section 32 is decremented by one (# 114), and the number is again set to # 10.
The processing of 6 or less is repeated.

In the normal processing, the film 1 is completely rewound and the rotation of the sprocket 10 is stopped by repeating the processing loop after # 106. Therefore, as shown in FIGS. 4A and 4B, the pulse signal output unit 20 outputs a signal of a constant level, and as a result, it is determined that the rewinding of the film 1 is completed (# 108). "N", # 110 "Y"). Then, this result is given to the stop control unit 34 (# 116), and the motor control unit 4
The motor 41 is stopped by 0.

On the other hand, the processing loop from # 106 onward is repeated, and the count number of the first counter section is sequentially decreased. When it reaches a predetermined value (“Y” in # 112), the second counter section 33 is started. Start counting at (# 118). In this case, although the rewinding operation of the film 1 is actually completed, the pulse signal output unit 20 often outputs a fine pulse signal as shown in FIG. 4C. Therefore, the count number in the second counter section 33 gradually increases (because # 106 and subsequent steps are repeated), and when the predetermined value is reached, it is determined that the rewinding operation has ended (“Y” in # 120). "). This result is given to the stop control unit 34 (# 116), and the motor control unit 40 stops the motor 41.

The predetermined value of the second counter section 33 may be, for example, "5", "10", or the like, which is a value sufficient for the film 1 to be completely wound up in the cartridge.

In the film rewinding apparatus shown in this embodiment, a second timer section may be provided instead of the second counter section 33. In this case, the first counter section 32 has a predetermined value. After that, the time counting of the second timer unit is started, and when the predetermined time has elapsed, it may be determined that the rewinding is completed.

Since the counter unit and the timer unit can be included in the microcomputer unit 10 by configuring the film rewinding device in this way, the number of parts does not increase, the manufacturing cost and the installation space are reduced. There are great advantages in terms of. In addition, control changes of the microcomputer software can be realized with very few changes because the counting unit can be shared.

[0039]

As described above, according to the film rewinding device of the present invention, the film rewinding device is provided with the two determination systems of the first end detecting means and the second end detecting means.
The end detection means detects the completion of film rewinding based on the state where the pulse signal output from the pulse signal output means has not changed, and the second end detection means counts by the counting means. After the number reaches a predetermined value, it is activated to detect the completion of rewinding of the film.

Therefore, depending on the stop position of the sprocket,
Depending on the location, a small pulse signal may continue to be output from the pulse signal output means, but even in this case, it is possible to reliably detect the end of film winding and accurately stop the rewinding operation. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a film rewinding device according to this embodiment.

FIG. 2 is a perspective view schematically showing the structure of a perforation of a film, a sprocket, and a pulse output unit which is interlocked with the sprocket.

FIG. 3 is a flowchart showing a flow of a rewinding process in the film rewinding device.

FIG. 4 is a waveform diagram showing various pulse signals output from a pulse signal output unit.

[Explanation of symbols]

1 ... Film, 2 ... Perforation, 10 ... Sprocket, 11 ... Projection pin, 20 ... Pulse signal output section, 3
DESCRIPTION OF SYMBOLS 1 ... Timer part (1st end detection means), 32 ... 1st count part (counting means), 33 ... 2nd count part (2nd end detection means), 34 ... Stop control part (stop control means), 41 ... Winding / rewinding motor (film driving means).

Claims (3)

[Claims] 1. A film rewinding device for rewinding a film loaded in a camera body, comprising: a film driving means for rewinding the film; and a plurality of projecting pins fitted to each perforation formed on the film. , A sprocket that rotates following the movement amount of the film, a pulse signal output unit that outputs a pulse signal in conjunction with the rotation of the sprocket, and a time interval of each pulse signal output from the pulse signal output unit. When the time is counted and a predetermined time interval is exceeded, the film is rewound based on the first end detection means for judging that the rewinding of the film is completed, and the pulse signal generated from the pulse signal means. And counting means for counting the number of films, and when the number counted by the counting means reaches a predetermined value. A rewinding operation by the film driving means based on a detection result of the second end detecting means which is activated and detects completion of rewinding of the film, and the detection result of the first end detecting means or the second end detecting means. And a stop control means for stopping the film rewinding device. 2. The second end detection means starts a new count based on the pulse signal output from the pulse signal output means when the count number by the counting means reaches a predetermined value. 2. The film rewinding device according to claim 1, wherein the film rewinding device is second counting means for determining that the rewinding of the film is completed when the count number reaches a predetermined value. 3. The second end detection means starts timing when the number counted by the counting means reaches a predetermined value, and rewinding of the film ends when a predetermined time elapses. 2. The film rewinding device according to claim 1, wherein the film rewinding device is a timer means for judging that the film has been rewound.