JPH01316729A - Winding controller - Google Patents

Abstract

PURPOSE:To simplify the mechanism and to secure the phase detection by stopping the operation of a winding means when a control means detects a specific number of specific-periodic pulses after detecting variation of the period of pulses. CONSTITUTION:While a winding means 101 is in operation, a pulse output means 102 generates pulses repeatedly at a specific period and generates at least one pulse different in period in the pulse train with the specific period. The control means 103 detects the variation in the period of the pulses and stops the winding operation of the winding means 101 by stopping a driving motor MT when detecting a specific number of pulses with the specific period after detecting the variation of the period. Consequently, the mechanism is simplified, an error due to detection timing is eliminated, and stable winding control is enabled.

Description

[Detailed description of the invention] A. Industrial application field The present invention relates to a winding control device for films, etc.

B. Conventional technology Conventionally, pulses are generated as the film is fed, these pulses are counted, and when the count value reaches a value equivalent to one frame of film, the film feeding motor is stopped and the film is fed. Devices for controlling hoisting are known.

FIG. 7 shows an example of this type of film winding control device. In the figure, film FI pulled out from a film cartridge 1 is wound by a spool 2 driven by a winding motor MT. At this time, the sprocket 3 that engages with the film perforation rotates.

This rotation is transmitted from the gear 4 coaxially provided integrally with the sprocket go to the gear 5, and the disc 6 with a slit hole provided coaxially and integrally with the gear 5 rotates. A photointerrupter 7 is provided so as to sandwich the disk 6 with the thrift holes from above and below, and a pulse is output from the photointerrupter 7 in synchronization with film feeding. That is, the disc 6 and the photointerrupter 7 constitute an encoder EN. Since there is no slippage between the rotation of the sprocket 3 and the advance of the film FI, they are completely synchronized, and therefore the pulses output from the encoder EN are also synchronized with the advance of the film. The encoder photointerrupter 7 is composed of a photodiode 71 and a phototransistor 72 as shown in FIG.

Furthermore, in FIG. 7, a cam 8 is coaxially integrated with the gear 5.
is provided, and the phase detection switch 9 is turned on once while the cam 8 rotates once. Assuming that the gear 5 rotates once while the film FI is being fed one frame, the switch 9 is turned on only once while the film FI is being fed one frame. Photo interrupter 7 and switch 9 are each control circuit 1
0, the control circuit 10 monitors when the switch 9 is turned on, counts the number of pulses input from the photointerrupter 7 after the switch 9 is turned on, and turns off the winding when the count value reaches a predetermined number. Controls the upper motor MT to stop.

9 is a signal waveform diagram of each part in FIG. 7, (a) is a pulse from the photointerrupter 7, (b) is a signal from the phase detection switch 9.
'', this low level signal is used as a phase detection signal. (c) shows the driving state of the hoisting motor MT,
It is driven by rHJ and braked by "L". Driving means energizing the motor, and braking is performed by stopping energizing the motor or applying the brake by electrically shorting the motor input terminals. In this embodiment, as shown in FIG. 9(Q), after the phase detection signal is generated, the hoisting motor MT
is driven intermittently and braking is gradually applied. When the feeding end position is reached, that is, when a predetermined number of pulses are counted, the brake signal is turned on, the motor input terminal is electrically shorted, and the brake is applied to the hoisting motor MT, as shown in (d). It takes. With such control.

The motor can be stopped without overrunning from the scheduled stop position.

As explained above, counting the pulses of the encoder EN based on the phase detection signal from the switch 9 and controlling the stop of the hoisting motor MT based on the counted value has the following first-order advantages.

Monitor the pulses from the encoder EN, and after counting the number equivalent to the amount of feed for one frame, stop the winding motor, and the film FI will be fed one frame at a time for each shot.
However, while shooting many frames, electrical noise may get on the pulse signal and cause a counting error, and braking at the end of frame advance may cause a slight phase shift in film stopping accuracy. , this may accumulate over the course of photographing a number of frames, resulting in the stop position being shifted by one pulse or more. Moreover,
-Once a phase shift occurs in this way, all subsequent phases remain shifted. Therefore, if you use the time when the phase detection signal turns on as a reference, count the pulses output from the encoder EN after that, and control the motor to stop when the number of pulses reaches the target value, the correct phase will be correct with respect to this phase reference every time. Since the film is fed, the winding of the film can be controlled with high accuracy.

C0 Problems to be Solved by the Invention However, the conventional device described above requires a mechanical switch 9 in addition to the encoder EN in order to obtain a one-phase detection signal, and the mechanism is complicated, and the switch 9 is The timing of turning on tends to fluctuate depending on the speed of film feeding, etc., and if it exceeds the pulse period, a control error will occur. Furthermore, the on-timing of the switch 9 may change due to aging, which may adversely affect the winding accuracy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a film winding control device that simplifies the mechanism by eliminating the conventional mechanical phase detection switch and can reliably detect one phase.

Means to solve the D0 problem This will be explained with reference to FIG. 1, which is a complaint correspondence diagram.

The present invention includes a drive motor MT and a winding means 10 that is driven by the drive motor MT and winds up a film or the like.
1, and pulse output means 102 that synchronizes with the operation of the hoisting means 101 and outputs a plurality of pulses as the operation progresses.
The present invention is applied to a hoisting control device comprising: and a control means 103 that controls the hoisting operation by the drive motor MT based on the pulses.

Then, while the pulse output means 102 is operated by the winding means 101, pulses are repeatedly generated at a predetermined period, and at least one pulse is generated at a period different from the period of this pulse in the pulse train of the predetermined period. The hoisting means 101 is configured to generate a pulse, and the control means 103 detects a change in the period of the pulse, and when a predetermined number of pulses of a predetermined period are detected after the change in the period is detected, the operation of the hoisting means 101 is completed. The above-mentioned problem is solved by controlling the drive motor MT to stop.

The E0 action pulse output means 102 repeatedly generates a pulse at a predetermined period while the hoisting means 101 is operating, and at least one pulse is generated at a period different from the period of this pulse in the pulse train of the predetermined period. Generates a pulse.

The control means 103 detects a change in the period of the pulse. When a predetermined number of pulses with a predetermined cycle are detected after the change in the cycle is detected, the drive motor MT is controlled to stop and the hoisting operation of the hoisting means 101 is completed.

F. Embodiment An embodiment of the present invention will be explained with reference to FIGS. 2 to 6. Note that the same parts as in FIG. 7 will be described with the same reference numerals.

FIG. 2 shows the overall circuit configuration. A control circuit 21 receives and receives a release signal, performs exposure control (not shown), and then controls film winding. That is, in order to drive the hoisting motor MT, the power transistor 22 is turned on to start supplying power to the hoisting motor MT, and then the process waits until the phase detection signal is monitored.

After the phase detection signal is detected, when a predetermined number of feedback pulses from the encoder EN including the slit-hole disk 16 and the photointerrupter 7 are counted, the hoisting motor MT is controlled to stop.

For example, braking is gradually applied before the count value of the feedback pulse reaches the target value, and when the count value reaches the target value at the stop position, the transistor 22 is turned off and the transistor 23 is turned on, and the input terminal of the hoisting motor MT is Short circuit and apply the brakes.

Here, as shown in FIG. 3, the slit-hole disc 16 has slit holes 16a formed at a predetermined angular pitch, and long slit holes 16b extending over a certain angular range. There is. Therefore, as shown in FIG. 4(a), the photointerrupter 7 sequentially outputs pulses of a predetermined period each time the slit hole 16a crosses the long slit hole 16a.
When 6b crosses, only one pulse with a period different from the predetermined period is outputted among the pulses with a predetermined period. In this embodiment, phase detection is performed by detecting that the pulse generation period has become significantly longer than before. In the figure, P1 indicates the section where the slit hole 1°6a is detected, that is, the section where short period pulses are detected, and P2 indicates the section where the long slit hole 16b is detected, that is, the section where long period pulses are detected. It shows.

Note that the pulse period is affected by the load and power supply voltage, and strictly speaking, the periods of sequentially generated pulses may differ, but in this example, when detecting period changes, changes in the load and power supply voltage are The reference value R, which will be described later, is set to be sufficiently large so that periodic fluctuations in the pulse due to this are not detected as periodic changes.

In this embodiment, the period of the pulse is monitored as follows.

Basically, in order to measure the period of the pulses output from the encoder EN, a high-speed timing clock is counted between each pulse, and the clock count value is compared with a reference value, and the count value is compared to the reference value. If it exceeds this, it is determined that the period has changed and a phase detection signal is generated.

FIG. 5(a) shows pulses obtained from the encoder EN, and the period of the pulses generated when the slit hole 16a passes the encoder EN is j Plt"-Pz+ j
In Pal tP4, the long slit hole 16b is the encoder E.
When passing through N, the period until the pulse is generated is t
As shown by ps, it becomes longer than before. Moreover, FIG. 5(b) is a waveform diagram showing the time change of the clock count value for period measurement. The clock is constantly input to a counter in the control circuit, and the count is cleared to zero at the negative edge of the pulse output from the encoder EN. While the normal slit hole 16a is passing through the encoder EN, the clock count value does not reach the reference value because the pulse period is short and is cleared to zero for each pulse. However, while the long slit hole 16b is passing through the encoder, the clock count value exceeds the standard value. When the control circuit 21 detects that the clock count value exceeds the reference value, it waits for the pulse from the encoder EN to fall, and uses this as a phase reference for film winding control, after which it further counts the output pulses from the encoder EN. do. Then, as described above, the hoisting motor MT is gradually braked from a certain count value after the phase reference, and when the target count value is reached, the input terminal of the hoisting motor MT is short-circuited to stop it.

Note that since the film feeding speed depends on the load and power supply voltage, if the reference value is fixed, there is a risk that the phase detection signal will be output erroneously. Therefore, in this example,
The reference value is successively corrected depending on the magnitude of the clock count value counted during one period of the pulse.

The above operation can be achieved by the processing procedure shown in FIG.

When the photographing of one frame is completed and a winding start command is issued, this procedure is started, and the transistor 22 is turned on in step S1.

As a result, the winding motor MT is started to be driven and winding of the film is started. As the film is fed, a pulse is output from the encoder EN, and in response to the falling edge of this pulse, an interrupt program (not shown) is started, and clocks per period of the pulse are counted. In step S2,
It is determined whether this clock count value CC is larger than the reference value R. If CC<R, the result is negative and the process proceeds to step S3. In step S3, it is determined whether or not the next pulse has fallen, and if it has fallen, the process proceeds to step S4, where the clock count value CC at that time is multiplied by an appropriate safety factor K to obtain a new reference value R. Then, in step S5, the clock count value CC is reset, and the process proceeds to step S2.

When CC≧R and step S2 is affirmed, step S
6, the count value CP of pulses from the encoder EN is reset, and counting of pulses generated from the encoder EN thereafter is started.

Then, in step S7, the count value CP is set to the reference value N.
Determine whether the value is greater than or not. When CP≧N, step S7 is determined, and in step S8, processing for braking the hoisting motor MT is performed6. For example, as shown in FIG. 4(b), the transistor 22 is turned on and off at a predetermined period. When the target count value is reached, the transistor 23 is turned on as shown in FIG. 4 (Q), the input of the hoisting motor MT is short-circuited, and the hoisting motor MT is braked and stopped.

In one or more embodiments, the explanation has been made assuming that the slitted disk 16 rotates once for the feed amount of one frame of film, but it may be configured to rotate by an integral multiple. Further, the brake processing is not particularly limited to the embodiment, and various methods are possible. Furthermore, the disc 16 with slit holes is not limited to the embodiments, and may include a disc with the long slit hole 16b cut out or a disc with no hole in that part, etc., in which pulses with different periods are included in a pulse train of a predetermined period. As long as at least one method occurs, it can be realized in various forms. Further, although the light transmission type photointerrupter 7 is used, a light reflection type photointerrupter 7 may be used. Furthermore, the encoder EN is not an optical type, but can take various forms such as a magnetic type and a sliding resistance type.

Furthermore, although film winding has been described above, the present invention can also be applied to motor winding control in shutter charging and the like.

Effects of the G9 Invention As described above, according to the present invention, not only can the mechanical phase switch required in conventional film feeding control etc. be abolished and the mechanism is simplified, but also the phase change can be improved because no mechanical switch is used. Since the detection signal is obtained in complete synchronization with film feeding, etc., there is no error caused by detection timing, and stable winding control is possible. Furthermore, if the film feeding speed is monitored in real time and fed back to detect periodic changes as in the embodiment, phase detection can be performed reliably even if the feeding speed changes due to load or power supply conditions.

[Brief explanation of the drawing]

FIG. 1 is a complaint correspondence diagram. Figures 2 to 6 are for explaining one embodiment. Figure 2 is a block diagram showing the overall configuration, Figure 3 is a perspective view of a slit disk, and Figures 4 (a) to (c) are Figure 2 is a waveform diagram of various signals, Figure 5 (a) is a waveform diagram showing pulses from the encoder, (b) is a waveform diagram showing changes in clock count value over time, and Figure 6 is a film winding control process. It is a flowchart showing a procedure. FIGS. 7 to 9 illustrate the prior art. FIG. 7 is an overall configuration diagram of the film winding control device, FIG. 8 is a detailed diagram of the photointerrupter, and FIGS. 9(a) to 9(d) are signal waveform diagrams of each part of FIG. 7. 2 Varnish spool 3: Sprocket 4.5: Gear 7: Photo interrupter 1o: Control circuit 16: Slit disk 21: Control circuit 22.23: Transistor 101: Winding means 102: Pulse generating means 103:
Control means MT two-winding motor patent applicant Nikon Co., Ltd. Patent attorney Nori Nagai 〆1- 〆1＼ -1N smoke
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Claims (1)

[Scope of Claims] A drive motor, a hoisting means that is driven by the drive motor to perform a hoisting operation, and a pulse output means that synchronizes with the operation of the hoisting means and outputs a plurality of pulses as the operation progresses. and a control means for controlling the hoisting operation by the drive motor based on the pulses, wherein the pulse output means outputs pulses at a predetermined period while the hoisting means is operating. is repeatedly generated, and at least one pulse is generated in the pulse train having a predetermined period at a period different from the period of this pulse, and the control means detects a change in the period of the pulse. The hoisting control device is characterized in that, when a predetermined number of pulses of the predetermined period are detected after detecting a change in the period, the drive motor is controlled to stop in order to complete the operation of the hoisting means.