JPH0353282Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an initial position setting device for a device driven by a pulse motor. In a device driven by a pulse motor, such as a pen drive device of a recorder, the position of the pen, etc. is undefined when the power is turned on, so after the power is turned on, the pen, etc. is moved to a predetermined starting position and then the recording operation is performed. It is necessary to do so. For this reason, normally, when the power is turned on, the pulse motor is first rotated to move the pen, etc. toward the start position, and a start position detection switch is placed at the start position, and when the pen hits this switch, the pulse motor is turned on. At the same time as stopping the pen, a pulse counter representing the position of the pen is reset. However, with this method, the movable range of the switch contact is wide, and the point at which the switch conducts within that range varies each time.No matter how precisely the switch position is adjusted, the starting position of the pen, etc. will vary, causing wear and tear on the switch contact. As a result, the starting position gradually shifts. The pulse motor has, for example, four poles 1, 2, 4, and 8 as shown in FIG. 1, and the rotor R is a permanent magnet whose upper end is the north pole at the position shown in the figure, for example. This N
The direction in which the pole is facing is indicated by an arrow coming out from the center.
Let us express the position of the rotor R. four poles 1,
2, 4, and 8, 1 and 4 form a pair, 2 and 8 form a pair, and the windings are in series at the paired poles. When pole 1 is excited to the south pole, pole 4 is excited to the north pole, and when the direction of the current is reversed, pole 1 becomes the north pole and pole 4 becomes the south pole. For convenience of explanation, each pole 1, 2, 4, 8 is
The case where a pole is excited is expressed as "exciting a pole." Therefore, when pole 1 is excited, the rotor R is at the arrow 1 position, and when poles 1 and 2 are simultaneously excited, the rotor R is at the arrow 3 position.
position, take the position of arrow 2 with only pole 2 excited, etc.
The relationship between pole excitation and rotor position is shown in the table below. In the table, 1 indicates energization and 0 indicates de-energization. Also, in the same table, the clock pulse number is the count value obtained by counting the clock pulses with a 3-bit octal counter.

[Table] As can be seen from the table above, one pole is excited for three clock pulses, and the adjacent magnetic pole in the clockwise direction is excited two clock pulses later. The pulse motor takes one of several positions as shown in Figure 1, and does not stabilize at any arbitrary position in the middle, so the pen position takes discrete positions corresponding to the stable position of the pulse motor. . For example, the interval between these discrete positions is 0.05 mm, and the pen moves this much with one clock pulse. Even in the initial position setting, the start position detection switch becomes conductive when the pulse motor is in one of the eight positions shown in FIG. 1. When this switch is turned on and the clock pulse counter is reset, magnetic pole 1 of the pulse motor is excited as shown in Figure 1. At this time, when the rotor is at position 2, 3 or 8, 9 (upper half) in Figure 1, The rotor returns to the position of arrow 1, but when the rotor is at the 6, 4, and 12 positions in the lower half, it is uncertain in which direction it will return to the position of arrow 1, and the initial position of the pen is Pulse motor 1
For example, a position difference of 0.4 mm occurs due to the rotation. To explain more specifically, in Fig. 3, the horizontal line indicates the direction of movement of the pen, the right side corresponds to the clockwise rotation of the pulse motor, the 0 point is the starting position of the pen, and the direction from the 0 point to the left is ±1. , 2, 3, etc. indicate the positions corresponding to one pulse of rotation of the pulse motor, and therefore the intervals between these points are
It is 0.05mm. The numbers representing each of these points correspond to the clock pulse numbers in the previous table. The range indicated by arrow E is the range in which the start position of the pen detected by the start position detection switch varies, and if the start position is detected within this range, pole 1 of the pulse motor is energized. You can hold the pen at position 0 in the diagram. When the start position is outside this range, for example, when the start position is detected at the +3 position on the right side, the pen may return to the 0 position when pole 1 of the pulse motor is energized.
The rotor of the pulse motor may rotate further clockwise from position 6 in Figure 1 and return to position 1.
At this time, the pen position is further 0.25mm from position 3.
This is the position moved to the right, and this becomes the starting position, so the position will shift by 0.4 mm from the 0 point. Therefore, if the position of the start position detection switch is adjusted so that it is conductive within the range where the rotor of the pulse motor is in the above-mentioned upper half position, the initial position of the driven member can be roughly detected as described above. This is done using a start position detection switch, and the driven member can be set at a predetermined constant position within a rough detection position range by the function of the pulse motor. However, even if the start position detection switch is initially set to the correct position, the detection position will fluctuate due to wear of the contacts, etc., so the detection position by the start position detection switch will be at the lower half position mentioned above at the rotor position of the pulse motor. If the driven member deviates from the range, as described above, the initial position of the driven member will be either the correct position or a position shifted by one rotation of the pulse motor from the correct position, and the initial position will become indefinite. The present invention is to detect when the initial position of a device driven by a pulse motor becomes unstable due to the above-mentioned points, and to adjust the position of the start position detection switch. It was done for a purpose. The present invention detects that the pulse motor is in the lower half position 6, 4, or 12 when the start position detection switch is turned on in FIG. 1, and displays a warning in this case. If a warning message appears, readjust the position of the start position detection switch. The present invention will be explained below with reference to Examples. FIG. 2 shows an embodiment of the present invention. PM is a pulse motor, P is a recorder pen, and these are attached to a rope stretched between pulleys w and w'. S is a start position detection switch, and when the pen P is at its initial position, the base P1 of the pen contacts the switch S, making it conductive. G is a clock pulse generator, C is a reversible counter, the counting output of which is compared with digital information of data to be recorded by a comparison circuit not shown, and addition/subtraction of the reversible counter is switched depending on the magnitude relationship. When the comparison results match, the input of the clock pulse to the counter is blocked and the pen stops at that position. When the power is turned on to start the recorder, the counter C is set to the subtraction side. The information of the lower 3 bits of the counter C is converted by the decoder D1 into a binary signal of the rotor position shown in the table above and applied to the poles 1 to 4 of the pulse motor PM.The output signal of the decoder D1 is sent to the detection circuit D2. applied. The detection circuit D2 detects that the rotor of the pulse motor PM is connected to the arrows 6, 4 in FIG.
12 positions is detected. This detection signal is applied to one input terminal of an AND gate An through an OR circuit OR. and gate an
When the start position detection switch S becomes conductive, an input is applied to the other input terminal of the gate, and the gate opens. The base P1 of the pen 1 closes the switch S and opens the AND gate An, at which time the pulse motor
When the PM rotor position is at any of the arrows 6, 4, and 12 in Figure 1, a signal is output from the OR circuit OR, so this signal is applied to the base of the transistor Q through the open gate An. Transistor Q becomes conductive. This causes the light emitting diode L to emit light and provide a warning display. The output of the AND gate An is applied to the inhibit gate K to close it.
When the switch S is closed, a signal is sent through the delay circuit d to the counter C through the inhibit gate K after a delay time slightly shorter than one pulse of the clock pulse, and the inhibit gate K resets it. is out, that is, when the pulse motor PM is stopped at the positions indicated by arrows 6, 4, and 12 in FIG. 1, it is closed, and in this case, resetting of the counter C is prevented. On the other hand, the clock pulse generator G is stopped by the output signal of the AND gate An. In other cases, the counter C is reset and the input signal to be recorded is 0 while the recording operation start switch (not shown) is turned on, so the input data of the comparison circuit (not shown) is 0 and the counter C is reset. As a result, a match symbol is output from the comparator circuit, the input of the clock pulse to the counter is blocked, and the pen stops at the starting position and waits.
When the counter is reset, the magnetic pole 1 of the pulse motor is excited by the decoder D1, the rotor returns to the position indicated by the arrow 1 in FIG. 1, and the pen P is set at the correct starting position. If the light emitting diode L emits light, switch the counter C to addition, open the pushbutton switch PB, restart the operation of the clock pulse generator G, and return the pen P a little.The recording pen will move away from the switch S and the light emitting diode will turn off. Therefore, if you turn off the power switch to stop the device, finely adjust the position of the start position detection switch S, then turn the power back on and restart the device, the above operation will be performed again and the recording pen will move toward the start position. It moves and stops. At this time, if no warning is given by the light emitted from the light emitting diode L, the position adjustment of the switch S has been completed. T is a screw for this fine adjustment. If the fine adjustment of the position of the switch S cannot be completed in one go, the above-mentioned steps may be repeated. At this time, the adjustment direction of the screw T is not specified, so for example, adjust the pen position by 0.1 mm in any direction.
Perform the above operation, and when the warning message appears, adjust screw T by 0.2 mm in the opposite direction. In most cases, this completes the adjustment. It is also possible to perform the manual operation in the above embodiment under automatic control by a computer. In this case, the counter C and decoder D shown in FIG.
1. Detection circuit D2, OR circuit OR, AND gate
The functions of An, delay circuit d, etc. can be realized by software using computer functions. In this case a motor is required to drive the adjusting screw T. Even if the device of the present invention is configured as described above and the initial position detection device of the device driven by a pulse motor fluctuates around the specific position of the rotor of the pulse motor, the initial position of the device is determined to be the specific position of the pulse motor. , the initial position can be set accurately. Although the above description is all related to a pen driving device of a recorder, the present invention is not limited to a recorder, but can also be applied to, for example, a wavelength scanning mechanism of a spectrometer.

[Brief explanation of drawings]

Figure 1 is a diagram showing the positional relationship between the magnetic poles and rotor of the pulse motor, Figure 2 is a diagram of an embodiment of the device of the present invention, and Figure 3 is the relationship between the starting position of the recording pen and the rotor position of the pulse motor. This is a graph showing. PM...Pulse motor, P...Recording pen, S
...Start position detection switch, C...Reversible counter, D1...Decoder, D2...6, 4, 12 detection circuit, L...Light emitting diode.

Claims (1)

[Claims for Utility Model Registration] (1) In a device driven by a pulse motor, means for detecting the initial position of a driven member whose mounting position is adjustable, and detecting that the rotor of the pulse motor is within a predetermined position range. and a device initial position setting device which adjusts the mounting position of the initial position detecting means when a detection signal is output from the initial position detecting means while the detection signal is output from the detecting means. (2) A warning device is activated by the output signal of a circuit that detects that both the initial position detection means and the detection means for detecting that the rotor of the pulse motor is within a predetermined position range are outputting signals, and the warning device is activated. The device initial position setting device according to claim 1, wherein the installation position of the initial position detection means is adjusted so as to stop the device. (3) The means for detecting the initial position and the means for detecting that the rotor of the pulse motor is within a predetermined position range are started by an output signal from a circuit that detects that both signals are being output, and the signal is automatically removed. 2. The device initial position setting device according to claim 1, wherein the installation position of the initial position detection means is adjusted at the same time.