JPS5822599A - Step-out correcting device for pulse motor - Google Patents

Abstract

PURPOSE:To enable to accurately shift the driven body to a prescribed position by a method wherein the pulse motor is revolved while a driving pulse number is being corrected by the corrective revolution detecting pulse number obtained on the basis of the revolution of the pulse motor. CONSTITUTION:The output pulse of a driving pulse generating circuit 11, with which the pulse motor will be driven, is inputted to a counter 12, and the output of which is inputted to a comparison circuit 13 and compared with the output of a counter 18. The output of a sensor, with which the revolution of the motor 3 will be detected, is applied to the counter 18 through the intermediary of a multiplying circuit 17. The decision whether the output of the comparison circuit 13 is positive or negative is given by a decision circuit 14, and in accordance with the above decision, said output is applied to the counter 12 through a correction circuit 15 or 16. The output of the counter 12 is compared with the output of a controlling circuit 9 at a comparison circuit 10, and it is then given to the driving pulse generating circuit 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse motor step-out correction device that is suitable for use in driving a tone arm of a linear tracking player.

Generally, when the tone arm is moved using a pulse motor, the position of the tone arm can be determined simply by detecting the number of pulses input to the pulse motor, so the lead-in and return positions of the tone arm relative to the record can be determined. This has the advantage that a special sensor is not required for detection and the structure is simple.

However, this pulse motor is not given enough pulses to move the tone arm to a predetermined position due to slippage due to the static load at startup, belt load applied to the power transmission system, or errors during rotation. There was a risk that the tone arm could not be moved to the predetermined position or moved beyond the predetermined position even though the tone arm was in use.

The present invention was invented in view of such problems with pulse motors, and one embodiment thereof will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block electric circuit diagram showing a step-out correction device for a pulse motor according to the present invention, and FIG. 2 is a schematic diagram of a tone arm drive mechanism of a record player equipped with the same device. , FIG. 3 is a side view of the main part of FIG. 2.

In such FIG. 2, the tone arm 5 as a driven body
is a rotating drum 1. It is fixed to a bell (2a) hung on the bell (a, lb), and is configured to slide back and forth as the bell (2a) moves.

Further, one end of the rotating drum 1b is connected to the other end of another belt 2b, which is connected to the belt IJ-3b of the pulse motor 3, and is configured to receive the rotational force of the pulse motor 3 (3). has been done.

Further, a sensor control piece 6 is fixed to the lower end of the rotating shaft 3a of the pulse motor 3, and is configured to turn ON/OFF the rotation sensor 4 provided near the lower end of the rotating shaft 3a.

As shown in FIG. 4, this rotation sensor 4 has a U-shaped main body 4a with a groove 4b' and a light emitting/receiving element sandwiched between them.
As shown in FIG. 5, the sensor control piece 6 is formed by providing one slit 6b on the periphery of a disc 6a, and the slit 6b for controlling the rotation timing corresponds to the rotation sensor 4. Accordingly, the rotation sensor 4 is turned on.

7 is a turntable.

In the above configuration, it is assumed that the pulse motor 3 is of a four-pole type and rotates once with the input of four pulses.

Next, in the electric circuit shown in FIG. 1, 9 is an operating circuit, which sends a driving pulse to the pulse motor 3 when moving the tone arm 5 from the rest position to the lead-in position (4). This is a circuit that executes setting of the required number of drive pulses, which is how many pulses need to be applied, and the above setting is performed by operating an appropriate volume.

10 is a first comparison circuit that compares the required number of drive pulses set by the operation circuit 9 with a count value outputted from a counter 12 (described later) (the required number of drive pulses outputted from the drive pulse generation circuit 11). When the two match, a stop signal is given to the drive pulse generation circuit 11 to stop the drive pulse generation operation of the generation circuit 11.

When the start signal is obtained from the switch circuit 8, the drive pulse generation circuit 11 starts generating drive pulses to drive the pulse motor 3, and when the above-mentioned stop signal is given, it stops generating the drive pulses and pulses the pulse motor 3. It is designed to stop the drive of the motor 3, and while the drive pulse is being output, the pulse is applied to the first counter 12 at the next stage.

The first counter 12 counts the driving pulses, and if there is a correction signal from a correction circuit 15.16, which will be described later, to this count value, adds or subtracts the numerical value of the correction signal, and applies the result to the first counter 12. The comparison circuit 10 and the second comparison circuit 13
It is designed to last.

17 is a multiplier circuit that obtains one pulse each time the rotation sensor 4 is turned on, and as described above, the pulse motor 3 rotates once with the input of four drive pulses.
Moreover, since one revolution of the pulse motor 3 generates one rotation detection pulse from the rotation sensor 4, each time a rotation detection pulse is input from the pulse motor 3, it is multiplied by 4. outputs the corrected rotation detection pulse number,
This corrected rotation detection pulse number is supplied to the next stage counter 18 for counting operation.

The second comparison circuit 13 compares the signal output from the first counter 12 and the signal output from the multiplication circuit 17, and uses the comparison result, that is, the difference between the two signals, to the next judgment circuit 1.
It is designed to be given to 4.

This judgment circuit 14 uses the signals obtained from the comparison circuit 13, that is, the output value of the counter 12 (the number of counted drive pulses) and the output value of the second counter 17 (the number of pulses according to the rotation of the pulse motor 3). When the former is smaller than the latter due to the difference, the correction circuit 16 outputs the necessary subtraction output (correction signal) to the counter 12 to subtract and correct the -1- difference, and when the former is smaller than the latter, it is corrected. The circuit 15 outputs an addition output (correction signal) necessary to add and correct the difference to the counter 12.

Note that these correction circuits 15 and 16 naturally output the number of pulses corresponding to the above-mentioned subtraction and addition values.

The present invention is constructed in a diagonal manner, and its operation will now be described.

Now, operate the volume on the operation circuit 9 to rotate the pulse motor 3 necessary for the tone arm 5 to move a predetermined distance (+ when using an LP record) from the rest position P to the lead-in position P2. In a state where the required number N of drive pulses corresponding to the number n is set, no rotation detection pulse is output from the rotation sensor 4 before the start signal is sent from the switch circuit 8 to the drive pulse generation circuit 11. Therefore, the output of the second counter 18 is 0”
Since the output of the first counter 12 is also 0'', the second comparison circuit 13 does not output a difference signal to the determination circuit 14, and therefore both correction circuits 1, 5, and 16 The first counter 12 maintains 0'' without outputting a correction output.

Then, when a play switch (not shown) is turned on and a start signal is applied from the switch circuit 8 to the drive pulse generation circuit 11, the circuit 11 generates a drive pulse, drives the pulse motor 3, and moves the tone arm to the second tone arm. In the direction of arrow A in the figure,
That is, while starting to move toward the lead-in position, the first
The counter 12 starts counting the number of drive pulses.

Further, the first comparator circuit 10 starts comparing the output value of the first counter 12 with the required number of drive pulses N set in the operation circuit 9, and the rotation sensor 4
6b of the sensor control piece 6 outputs a rotation detection pulse every time the sensor control piece 6 rotates, and the multiplication circuit 17 multiplies this by 4 every time the rotation detection pulse is input, and the second counter 18 counts the result. let

In this way, the pulse motor 3 is driven in accordance with the pulse generation operation of the drive pulse generation circuit 11, and each counter 1
2 and 1.8 start counting the number of drive pulses and the number of rotation detection pulses of the pulse motor 3, respectively, the second comparison circuit 13 compares the output values of both counters, and if there is no difference between the two, that is, If the pulse motor 3 does not step out and rotates accurately following the number of applied drive pulses, the second comparison circuit 13 does not output a difference signal, and therefore the judgment Since the circuit 14 does not output a correction signal from any of the correction circuits 15 and 16, the first counter 12
does not add or subtract the above count value.

However, for some reason, an abnormality occurs in the rotation of the pulse motor 3, and as a result, the output value of the second counter 18 (
Multiplying circuit 1 multiplies the rotation detection pulse output from rotation sensor 4.
When the number of corrected rotation detection pulses (number of corrected rotation detection pulses multiplied by 4 by 7) produces an error of ±n with respect to the output value (number of drive pulses) of the first counter 12, the second comparison circuit 13 calculates the difference (+n or - n
) is applied to the judgment circuit 14, and when the difference is +n, the judgment circuit 14 drives the correction circuit 15 and sends a correction signal to the counter 12 indicating that n values should be added.
When the difference is -n, the correction circuit 16 is driven to send a correction signal to the counter 12 indicating that n values should be subtracted from this difference. This causes the counter 12 to perform an operation of subtracting n from the count value.

As a result, the counter 12 corrects the count value to the corrected rotation detection pulse number and changes that value to the first. The second comparison circuits 10 and 13 are supplied again. If the count value is corrected, the second comparison circuit 13 deactivates the output of the difference signal.

In this way, the rotation of the pulse smoke 3 is corrected by the number of corrected rotation detection pulses obtained based on the rotation of the pulse motor 3 while correcting the number of drive pulses obtained from the drive pulse generation circuit 11 and counted by the first counter. progresses,
When the tone arm 5 reaches the lead-in position P2, the output value of the first counter 12, that is, the number of drive pulses matches the required number of drive pulses N set in the operation circuit 9, so the first comparison circuit 10 The stop signal is driven by the pulse generation circuit 11.
, the oscillation operation of the circuit 11 is stopped, and as a result, the drive of the pulse motor 3 is also stopped, and the tone arm 5 is kept at the lead-in position P2.

Thereafter, the tone arm 5 is lead-in by another well-known device (not shown) to engage the pickup with the sound groove on the record.

Since the present invention is configured in an upwardly inclined manner, it is possible to reliably move a driven object, for example, the tone arm shown in the embodiment, to a predetermined position, and to provide a highly reliable pulse motor step-out correction device. This is an excellent invention that can be provided.

[Brief explanation of drawings]

FIG. 1 is a block electrical circuit diagram of one embodiment of the device according to the present invention, FIG. 2 is a schematic diagram of the configuration of a linear tracking player equipped with the same device, and FIG. 3 is a schematic diagram of the main components of FIG. FIG. 4 is a configuration diagram of the rotation sensor, and FIG. 5 is a top view of the sensor control piece. 3: Pulse motor, 4: Rotation sensor, 11: Drive pulse generation circuit, 12: First counter. 13: Second comparison circuit, 1.5 (16): Correction circuit. 17: Multiplier circuit, 18: Second counter. Agent Patent Attorney Aihiko Fukushi

Claims (1)

[Claims] 1. A pulse motor rotated by drive pulses given by a drive pulse generation circuit, a first counter that counts the number of the drive pulses, and one or more counters that detect the rotation of the pulse motor for each rotation. a rotation sensor means for outputting rotation detection pulses; and a rotation sensor means for outputting rotation detection pulses outputted from the rotation sensor means.
circuit means for correcting the number of corrected rotation detection pulses by correcting the number of rotation detection pulses outputted for each rotation and outputting the number of corrected rotation detection pulses; and a second circuit for counting the number of corrected rotation detection pulses output by the circuit means. a counter, a comparison circuit means for comparing the output values of the second counter and the first counter, and a correction circuit means for outputting a correction signal based on a difference signal outputted by the comparison circuit means, The first counter corrects the count value of the drive pulse based on the correction signal output from the correction circuit means, and always makes the count value match the corrected rotation detection pulse number. Pulse motor step-out correction device.