JPS6129827A - Controller of rotary shutter opening angle - Google Patents

Abstract

PURPOSE:To detect a trouble and to break the power supply to a step motor when the output of a switch is not changed, by driving initially a rotary shutter in the opening or closing direction if the output of a detecting means exists in the initial state. CONSTITUTION:When the opening angle is increased and a lever 3 reaches a section 2a, the output of an AND gate 4 goes to the high level at the timing of generation of an A-phase pulse, and an FF6 is reset to terminate initialization of the opening angle. If the FF6 is not reset through the A-phase pulse is generated N2-number of times, the trouble of a switch 2 or an opening angle control mechanism is discriminated, and the output of a counter 15 goes to the high level, and a pulse generating circuit 10 is reset to stop driving a motor 19, and a trouble warning signal is outputted to a terminal 21 by the output of an AND gate 13. Thus, the trouble of the detecting means which detects a specific opening angle when the opening angle of the rotary shutter is initialized is detected, and the shutter is set surely to the specific opening angle.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a rotary shutter opening angle drive control device that variably controls the opening angle of a rotary shutter, and more particularly to a rotary shutter opening angle drive control device that sets the opening angle to a specific opening angle.

<Prior Art> When electrically variably controlling the opening angle of a rotary shutter, it is necessary to initially set the rotary shutter to a specific opening angle. For initial setting, the rotary shutter is usually provided with a detection switch that detects its specific opening angle.

If there is no detection output from the detection switch in the initial state, initial setting is performed by driving the opening angle in the opening direction or closing direction and stopping at the position at the time of detection.

Further, if there is a detection output in the initial state, the diaphragm is assumed to be at a specific opening angle and subsequent operations are controlled.

However, if the detection switch is malfunctioning, even if there is a detection output for the first time, it is not known whether the position is at a specific opening angle or not, and the malfunction of the detection switch itself cannot be determined.

<Objective> In view of the above-mentioned points, the present invention aims to provide a rotary shutter opening angle drive control device that can reliably set the rotary shutter to a specific opening angle at the time of initial setting.

Another object of the present invention is to provide a rotary shutter opening angle control device that can determine a failure of a detection means for detecting a specific opening angle.

<Embodiment> FIG. 1 is a diagram showing the relationship between the opening angle and each phase of a step motor that variably controls the opening angle of a rotary shutter. Each phase of the step motor is numbered for explanation.

The step motor of this embodiment has four phases, each phase being AlB, C,
It is set as D. Here, if the motor is driven in the order of A-+B-+C-+D, the opening angle will widen, and conversely, D-C-+B-+A
When driven in this order, the opening angle becomes narrower.

In this embodiment, a detection switch (detection means) for detecting the maximum opening angle is provided.

Below the 32nd phase, the detection switch is off, and above the 33rd sum, the detection switch is on. The detection switch is checked with human phase, and the opening angle is 180° on phase 34.
This position is the maximum opening angle position. In other words, 3
The detection switch changes between phases 2 and 33, but 34
By checking the detection switch in the th phase, mechanical deviation of the detection switch is compensated for.

Also, the 34th phase is originally the maximum opening angle, but the aperture is moved to the 40th phase to prevent the step motor from being driven beyond the shutter limit due to a failure of the step motor or detection switch. It is structured in such a way that it can be done.

FIG. 2 is a control circuit diagram of this embodiment, where 1 is an initial setting switch, 2a is a detection switch section electrically connected to a high level, 2b is an electrically grounded detection switch section,
2c is an insulating member that insulates between 2a and 2b; 3 is a detection switch lever that moves by electrically contacting the sections of 2a and 2b in conjunction with opening and closing of the opening angle; 2a, 2b, 2c, and 3 are detection switches 2. 4, 7, 9゜12.13 are AND gates, 5 and 16 are OR gates, 6 is a flip-flop, 8 is an inverter, 10 is an open direction drive pulse generation circuit that generates pulses in the order of A-+B → C → D , 11 is D
-+C→B-" A pulse generation circuit for closing direction drive that generates pulses in the order of A; 14 is a counter that outputs a signal when the A-phase pulse of the pulse generation circuit 10 is counted N1 times; 15 is A of the pulse generation circuit 11. A counter that outputs a signal when the phase pulse is counted N1 times, 17° and 18 are step motor drive circuits, 19 is a step motor for controlling the opening angle, and 20 is an opening angle control mechanism that detects switch levers 3 in conjunction with changes in the opening angle. 21 is an output terminal that outputs a failure warning signal.

<Operation explanation> Next, the operation of this embodiment will be explained.

First, when the initial setting switch 1 is turned on, the output of the flip-flop 6 becomes high level. At this time, when the switch lever 3 is in the position of the intercept 2b, that is, when the aperture is not set at the maximum opening angle position, the output of the AND gate 9 becomes high level. As a result, the opening direction drive pulse generation circuit 1
0 is triggered and pulses that drive the opening angle in the direction of opening are generated continuously, and the opening angle moves in the opening direction.

When the lever 3 reaches the intercept 2a position, the output of the AND gate 4 becomes high level at the time when the facial pulse is generated.
The flip-flop 6 is reset and the initial setting of the opening angle is completed.

However, if the clip-flock 6 is not reset even if the human phase pulse is generated N2 times at this time, it is determined that the switch 2 or the opening angle control mechanism is malfunctioning, the output of the counter 15 becomes high level, and the pulse generation circuit 10 is turned off. reset,
The drive of the motor 19 is stopped and a failure warning signal is outputted to the terminal 21 by the output of the AND gate 13.

Next, when the switch lever 3 of the detection switch 2 is in the switch intercept 2a position, that is, in the maximum opening state, the output of the AND gate 7 becomes high level. This triggers the closing direction drive pulse generating circuit 11, and pulses for driving the opening angle in the closing direction are continuously generated, thereby driving the opening angle in the closing direction. Then, when the lever 3 moves to the intercept 2b side, the output of the detection switch 2 becomes low level, and the output of the AND gate 7 becomes low level, and the closing direction drive pulse generation circuit 11 is reset. At the same time, the output of the AND gate 9 becomes high level, and the pulse generation circuit 1 for driving in the open direction
0 is activated, and the drive circuit 19 drives the opening angle in the direction of opening. If the output of the detection switch is at a high level (that is, the maximum opening angle) when the pulse generating circuit 10 outputs a human phase pulse, the output of the AND gate 4 becomes a high level, the output of the OR gate 5 also becomes a high level, and the flip-flop 6 is reset and the initial setting operation to the maximum opening angle position is completed.

When the opening angle is being driven in the direction of closing, the counter 14 counts the number of pulses of the human face, and when the number of pulses reaches N times, it outputs a reset signal for the pulse generator 11 to stop the generation of pulses. make it stop.

That is, if the output of the detection switch 2 is at a high level even though the opening angle has been driven N1 times in the direction of closing, this means that the state of the detection switch 2 is not normal, and the output of the OR gate 16 will be at a high level. This is output as a failure warning signal to the terminal 21, and then to a display or speaker (not shown). At the same time, the flip-flop 6 is reset via the OR gate 5.

In addition, when driving in the opening direction, the A phase pulse is counted by the counter 15 as described above, and if the output of the open switch 2 remains at a high level even after the counter 15 counts N2 times, a pulse is generated. The output of the device 10 is stopped and a failure warning signal is output to the terminal 21.

This warning signal is also connected to the input of the OR gate 5 and resets the flip-flop 6 to stop the initial setting operation to the maximum opening angle position. Pulse counter value N, ,
N! The setting is as shown in Figure 1. If the detection switch switching point is provided, the tag will be applied 3 to 10 times, N! should be 9 times.

As described above, even when the output of the detection switch for detecting the maximum position is at a high level, the open position can be reliably detected because the switch is once driven in the closing direction. Further, if the output of the detection switch does not change, it is also possible to detect a failure of the detection switch. Furthermore, in the event of a failure, the power to the step motor is cut off, thereby preventing accidents such as damage to the opening angle control mechanism.

In this embodiment, the output of the detection switch is set to a high level on the maximum opening angle side, but it may be configured so that it becomes a low level on the maximum opening angle side.

Further, in this embodiment, the opening angle is initially set to the maximum opening angle, but conversely, it is possible to initialize the opening angle to the minimum opening angle or to an intermediate opening angle with a similar configuration.

Further, these operations can also be realized using a microcomputer. Further, it is desirable that the initial setting switch is turned on in conjunction with turning on the power of the camera.

<Effects> As described above, according to the present invention, it is possible to detect a failure of the detection means for detecting a specific opening angle at the time of initial setting of the opening angle of the rotary shutter, and the shutter can be reliably set to the specific opening angle. It becomes possible to do so.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between each phase of a step motor that variably controls the opening angle and the opening angle, and FIG. 2 is a control circuit diagram of this embodiment. In the figure, 1 is an initial setting switch, 2 is a detection switch as a detection means, 2a and 2b are intercepts, 3 is a detection switch lever, 10 is a pulse generation circuit for driving in the opening direction, 11 is a pulse generation circuit for driving in the closing direction, 14.15 is the counter,
Reference numeral 19 indicates a step motor for controlling the opening angle, 20 indicates an opening angle control mechanism, and 21 indicates an output terminal for a failure warning signal.

Claims (3)

[Claims] (1) A rotary shutter opening angle drive control device that variably controls the opening angle of a rotary shutter, comprising a detection means for detecting a specific opening angle of the shutter, and a setting means for setting the rotary shutter to the specific opening angle. . A rotary shutter opening angle control device, wherein the setting means initially drives the opening angle of the rotary shutter in an opening direction or a closing direction when there is a detection output from the detection means in an initial state. (2) The rotary shutter opening angle control device according to item 1, wherein the setting means outputs a warning signal when the detection output of the detection means does not disappear even after being driven by a predetermined amount in the direction of the initial drive. . (3) The rotary shutter opening angle control device according to item 1, wherein the setting means is driven in a direction opposite to the initial driving direction after the initial driving.