JPH052846A - Position controller for movable body - Google Patents

Abstract

PURPOSE:To increase the holding force of a position signal by permitting the specified signal holding specified time width to feed back to an input side and re-inserting the specified portion of DC so as to obtain the position signal in a sample/hold circuit. CONSTITUTION:An optical scale 8 and a detecting equipment 9 constitute an encoder generating a pseudo sin-wave signal having the phase difference of the specific angle of about 90 deg.. The pseudo sin-wave 2-phase signals corresponding to the displacement of a carriage 2 are outputted from the encoder, the sum signal and difference signal of the signals in the respective phases are generated from an adding circuit 12 and a subtracting circuit 11 and the exclusive logical sum output of the both signal is obtained from an exclusive logical sum circuit 18. The signal of one of 2-phases within the 2-phases signals and the signal obtained by inverting (16) the signal are changed-over by a changing- over switch 22 in accordance with the level of the output signal so that the AC component of the signal is inputted to the sample/hold circuit 23 and specified time width is held. Then, the output of the circuit 23 is fed-back with a drive circuit 27 so as to re-insert the specified portion of DC.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable body position control device,
In particular, the present invention relates to a movable body position control device suitable for positioning a recording / reproducing element in a recording / reproducing device.

[0002]

2. Description of the Related Art Positioning a movable body at a specific position is performed in many technical fields. For example, when recording an information signal on an optical disk or a magnetic disk, or reproducing an information signal from an optical disk or a magnetic disk, information is recorded at a predetermined position on the disk,
The information recorded on the disk is searched and reproduced, but in that case, it is necessary to position the recording / reproducing element (optical head, magnetic head) at the target position in a short time. It is said that. FIG. 3 is a perspective view of an optical disk recording / reproducing apparatus shown as an example of the recording / reproducing apparatus. In FIG. 3, M is a motor for driving and rotating the disk, 1 is an optical disk, 2 is a carriage (transport body), and 5 is an optical head. Is a magnetic path member of the linear motor, and 7 is a drive coil of the linear motor. The motor M is used during the recording operation of the information signal on the optical disc 1 and the reproducing operation of the information signal from the optical disc 1. Illustrated so that the condensing point by the recording light or the reproducing light, which is driven and rotated at a predetermined number of revolutions and condensed by the lens 5 of the optical head, can be positioned at a target track position on the optical disc 1 in a short time. Target position signal given by the control unit, optical scale (linear scale) attached to the movable part and detector provided on the fixed part The moving coil, that is, the speed control signal and the position control signal sequentially generated according to the position signal output from the position detector generated corresponding to the position of the optical head, are applied to the drive coil 7 of the linear motor. By being supplied and driving the linear motor, the carriage 2 moves along the guide rod and moves the position of the light spot focused by the lens 5 in the optical head to the target track position at high speed. To

[0003]

A position signal used for position control in a conventional device is generated by using an encoder composed of an optical scale and a detector for speed control and position control of a movable body. Only one phase signal of the pseudo sine wave two phase signals having a phase difference of 90 degrees was used. FIG. 4 is a diagram for explaining the position detecting operation in the conventional device in which the position control of the movable body is performed by using the signal of one phase as described above, and the arrow in FIG. The position is the point where the reference voltage Vref and the signal for position control intersect, that is, the stable point of positioning. As shown in FIG. 4, 1
When the position control is performed using the phase signal, the stable point of positioning exists for each pitch of the encoder, so the position signal generated by the encoder has periodicity. The torque is small. In particular, the shorter the cycle (displacement), the smaller the holding force. Therefore, for example, when applied to the position control of the carriage 2 in the recording / reproducing apparatus as illustrated in FIG. 3, the position control is performed so that the carriage 2 is stopped at the target position after the seek as the encoder pitch becomes smaller. Is difficult to perform, and when the encoder pitch decreases, the carriage 2 may be positioned at another stable point without stopping at the target position after the seek. A measure was called for.

[0004]

According to the present invention, a pseudo-sine wave two-phase signal having a phase difference of a predetermined angle within an angle in the vicinity of 90 degrees corresponds to the displacement of a movable body whose position is to be controlled. Of the two-phase signals generated by the signal generating means, the means for obtaining the sum signal of the signals of the respective phases of the two-phase signals generated by the signal generating means, and the signal of the respective phases of the two-phase signals generated by the signal generating means. A means for obtaining a difference signal; a means for obtaining a binarized signal with respect to the sum signal and the difference signal using the center value of each signal as a threshold; and a binarized signal of the sum signal and the difference signal. Means for obtaining an exclusive OR output signal with the binarized signal, and a signal of one phase of the signals of each phase in the two-phase signal generated by the signal generating means by the exclusive OR output signal Signal selecting means for selecting the The signal switching means for switching and outputting the output signal from the selecting means and the signal obtained by inverting the polarity of the output signal from the signal selecting means as a switching signal of the binarized signal for the difference signal. Means for inputting the AC component of the output signal from the signal switching means to the sample and hold circuit, and the signal level of the signal input at the time position of each edge in the exclusive OR output signal is determined from the time position described above. (EN) Provided is a position control device for a movable body, which comprises means for feeding back an output of a sample hold circuit which is held for a time width to an input side and re-inserting a predetermined DC component.

[0005]

The encoder generates the pseudo-sine wave two-phase signal having a phase difference of a predetermined angle within an angle of about 90 degrees, and the pseudo-sine wave corresponding to the displacement of the movable body whose position is to be controlled. Output a two-phase wave signal. A sum signal and a difference signal of each phase signal in the two-phase signal generated by the encoder are created, and a binarized signal is generated for the sum signal and the difference signal using the center value of each signal as a threshold value. .. An exclusive OR output signal of the binarized signal of the sum signal and the binarized signal of the difference signal is obtained. Corresponding to the signal level of the exclusive OR output signal,
The signal of one phase of the signals of each phase in the two-phase signal generated by the encoder is selected. By switching the two signals, the selected signal and the signal obtained by inverting the polarity of the selected signal, by using the binarized signal for the difference signal as the switching signal, Either one of the two signals is output. An AC component obtained by passing the output signal through the AC coupling circuit is input to the sample hold circuit. The signal level of the signal input to the sample hold circuit at the time position of each edge in the exclusive OR output signal is held in the sample hold circuit for a predetermined time width from the time position described above,
Further, the output of the sample hold circuit is fed back to the input side so that a predetermined DC component is reinserted, and the linear range of the position signal can be expanded within the range of the time constant in the DC component reinsertion circuit described above. A position signal can be generated which can increase the force.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The concrete contents of the movable body position control apparatus of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a schematic configuration of an embodiment in which the movable body position control apparatus of the present invention is applied to an optical disk recording / reproducing apparatus, and FIG. 2 shows the operation of the movable body position control apparatus of the present invention. It is a waveform diagram for explaining. In FIG. 1, 1 is an optical disk, 2 is a carriage (transport body) of an optical head, and 3 and 4
Is a guide rod that regulates the moving direction of the carriage 2 described above,
Reference numeral 5 is a lens (objective lens) of the optical head, and 6 is a magnetic path member of a magnetic field generating device in the linear motor that drives the carriage 2 described above. The magnetic path member 6 is fixed to a fixed portion of the device. Reference numeral 7 is a drive coil of the linear motor described above, and the drive coil 7 is fixed to the carriage 2 and has a magnetic flux generated from the magnetic path member 6 and a current flowing through the drive coil 7. By the electromagnetic force between the carriage 2 and the guide rod 3,
4 is driven and displaced in the extending direction. An optical scale (linear scale) 8 is attached to the carriage 2 described above. Further, the detector 9 provided on the fixed part of the device is
Pseudo-sine wave two-phase signals Sa and Sb having a phase difference of a predetermined angle within an angle of about 90 degrees when the optical scale 8 is displaced integrally with the carriage 2 (FIG. 2).
(See (a) and (b) of FIG. 2) and supplies the two-phase signal to the amplifier 10. The optical scale (linear scale) 8 attached to the carriage 2 and the detector 9 provided on the fixed part of the device have a pseudo phase difference of a predetermined angle within an angle of about 90 degrees. An encoder that generates a sine wave two-phase signal is configured. The phase difference between the signals of each phase in the pseudo sine wave two-phase signal output from the encoder may be an angle slightly deviated from 90 degrees, but it is desirable that the phase difference be 90 degrees. It is an embodiment.

The encoder detector 9 is associated with the displacement of the carriage 2, that is, the displacement of the objective lens 5 of the optical head.
The pseudo-sinusoidal two-phase signals Sa and Sb having a phase difference of a predetermined angle within the above-mentioned angle of about 90 degrees output from the above are amplified by the amplifier 10, and one of the signals Sa is It is supplied to the fixed contact a of the changeover switch 15 and also to the differentiating circuit 28, the adding circuit 12 and the subtracting circuit 11, and the other signal Sb is supplied to the fixed contact b of the changeover switch 15. It is also supplied to the differentiating circuit 29, the adding circuit 12, and the subtracting circuit 11. The movable contact v of the changeover switch 15 is connected to the fixed contact a of the changeover switch 17 and is also supplied as an input signal to the polarity reversing circuit (reversing circuit) 16. The movable contact v of the changeover switch 15 is switched to the fixed contact a side when the signal Si (see (i) of FIG. 2) output from the delay circuit 20 described later is at a high level. Then, the signal Sa is output from the movable contact v, and when the signal Si output from the delay circuit 20 is at a low level, the movable contact v is switched to the fixed contact b side. The signal Sb is output.

The output signal of the inversion circuit 16 is supplied to the fixed contact b of the changeover switch 17. Further, the movable contact v of the changeover switch 17 described above has a capacitor C and a switch 22 used as an AC coupling circuit.
And is connected to one end of. The movable contact v of the changeover switch 15 is switched to the fixed contact b side when the signal Sh (see (h) of FIG. 2) output from the delay circuit 21 described later is at high level. In addition, when the signal Sh output from the delay circuit 21 is at the low level, it is switched to the fixed contact a side. The capacitor C and the other end of the switch 22 are connected to the input side of the sample hold circuit 23. Sample hold circuit 2 described above
The input side of 3 is connected to the reference voltage source Vref via the resistor R, and is also connected to the input terminal of the subtraction circuit 24 to which the output signal of the sample hold circuit 23 is supplied as the minuend signal. The capacitor C, the resistor R, the reference voltage source Vref, and the sample hold circuit 23 described above.
Is an operation of re-inserting a DC component in an AC signal supplied to the input side of the sample hold circuit 23 via a capacitor C functioning as an AC coupling circuit.

The signal Sj (see (j) of FIG. 2) output from the pulse generating circuit 19 described later is shown in (m) of FIG. 2 corresponding to the low-level period. A diagram corresponding to the period in which the input signal is supplied as a sample value to the sample hold circuit 23 during the low level period of Sjm, and the signal Sj is in the high level period. The sample-hold circuit 23 holds the sampled value of the input signal at the time when the signal Sj changes from the low level state to the high level state during the high level period of Sjm of (m) 2. It is in a state of being.

A signal output from a movable contact v of a changeover switch 32, which will be described later, is supplied to the subtracting circuit 24 as a subtraction signal, and the output signal from the subtracting circuit 24 is a changeover switch. It is supplied to the fixed contact b of 26. A speed control signal γ output from a subtraction circuit 35, which will be described later, is supplied to the fixed contact a of the changeover switch 26. Changeover switch 2
The switching operation of the movable contact v of 6 is performed by a switching control signal supplied to a switching control signal supply terminal 25 from a control circuit (not shown). When the movable contact v of the changeover switch 26 is switched to the fixed contact a side, the circuit arrangement shown in FIG. 1 performs the speed control operation, and the movable contact v of the changeover switch 26 is changed to the fixed contact b side. The circuit arrangement shown in FIG. 1 in the switched state performs the position control operation. When the circuit arrangement shown in FIG. 1 performs the speed control operation, the switch 22 is controlled by the control signal supplied to the terminal 36 from the control circuit (not shown) so as to be turned on. When the circuit arrangement shown in (1) performs the position control operation, the switch 22 is controlled to be turned off by the control signal supplied to the terminal 36 from the control circuit (not shown).

The differentiating circuit 28, to which the signal Sa is supplied from the output side of the amplifier 10, gives the output signal therefrom to the fixed contact a of the changeover switch 30, and the signal Sb is supplied from the output side of the amplifier 10. The differentiating circuit 29 presents the output signal therefrom to the fixed contact b of the changeover switch 30. In the changeover switch 30 described above, the movable contact v is switched between the fixed contact a side and the fixed contact side b by an output signal Sg from the exclusive OR circuit 18 described later (see (g) of FIG. 2). The signal output from the movable contact v of the changeover switch 30 is supplied to the fixed contact b of the changeover switch 32, and is also supplied to the fixed contact a of the changeover switch 32 via the polarity reversing circuit (inversion circuit) 31. There is. The movable contact v of the switch 32 is switched between the fixed contact a side and the fixed contact b side using a signal Sf (see (f) of FIG. 2) output from the comparison circuit 13 described later as a switching control signal.

The output signal from the movable contact v of the changeover switch 32 is supplied to the subtraction circuit 24 as a subtraction signal as described above, and is also supplied to the gain setting circuit 33 of the speed control circuit. The output signal α from the gain setting circuit 33 is supplied to the subtraction circuit 35 as a subtraction signal, and the subtraction circuit 35 is supplied with the signal β output from the reference speed profile generation circuit 34. The speed error signal γ generated by the subtraction performed at 35 is supplied to the fixed contact a of the changeover switch 26 as described above. In the upper right of FIG. 1, α, β,
A change mode of γ on the time axis is illustrated, and the movable contact v of the changeover switch 26 is switched from the fixed contact a side to the fixed contact b side at the time when the target position is reached in the figure, and is also supplied to the terminal 36. The switch control signal causes the switch 22 to change from the on state to the off state, and the circuit arrangement of FIG. 1 is switched from the speed control operation to the position control operation.

In a state in which the movable contact v of the changeover switch 26 is changed over to the fixed contact a side and the circuit arrangement of FIG.
The speed control signal output from the movable contact v is supplied to the drive circuit 27, and the output signal of the drive circuit 27 is supplied to the drive coil 7 of the linear motor to perform the speed control operation. 2 is switched to the fixed contact b side and the circuit arrangement in FIG. 1 is performing the position control operation, the position control signal output from the movable contact v of the changeover switch 26 is the drive circuit. The position control operation is performed by supplying the output signal of the drive circuit 27 to the drive coil 7 of the linear motor.

A predetermined angle within the two signals output from the amplifier 10, that is, the angle near 90 degrees output from the encoder detector 9 corresponding to the displacement of the objective lens 5 of the optical head. The pseudo-sine wave two-phase signals Sa and Sb having the phase difference of are added by the adder circuit 12 and supplied to the comparison circuit 14 as the signal Sc (= Sa + Sb) shown in FIG. The pseudo-sine wave two-phase signals Sa and Sb are subtracted from the signal Sa in the subtraction circuit 11 to be a signal Sd (= Sa-Sb) shown in FIG. 2D. It is supplied to the comparison circuit 13. In the comparison circuit 14 described above, the binarized signal S is set with the central value of the signal Sc supplied thereto as a threshold value.
e (see (e) of FIG. 2) to generate an exclusive OR circuit 1
In the comparison circuit 13 described above, the binarized signal Sf is set with the central value of the signal Sd supplied thereto as a threshold value.
2 (see (f) in FIG. 2) is generated, and the signal Sf is supplied to the exclusive OR circuit 18 and the delay circuit 21, and is also supplied to the changeover switch 32 as a changeover control signal as described above. To be done.

In the exclusive OR circuit 18 to which the two signals Se and Sf supplied from the comparison circuits 14 and 13 are input as described above, a diagram showing the exclusive OR of the two signals Se and Sf given thereto. The signal Sg like (g) of 2 is output. The signal Sg is used for the pulse generation circuit 19 and the delay circuit 2
0 and is also supplied to the changeover switch 30 as a changeover control signal as described above. In the pulse generation circuit 19 to which the output signal Sg of the exclusive OR circuit 18 is supplied as described above, the signal Sg supplied thereto
A pulse signal Sj having a predetermined time width (see (j) in FIG. 2) is generated from the time position of each edge portion in, and it is used as a sample pulse and a hold pulse in the sample hold circuit 23 as described above. give. Further, the delay circuit 20 supplied with the output signal Sg of the exclusive OR circuit 18 outputs the signal Sg supplied thereto as a signal Si in a state delayed by a predetermined time, and outputs the signal Si. As described above, it is supplied to the changeover switch 15 as a changeover control signal. Further, the delay circuit 21 to which the output signal Sf from the comparison circuit 13 is supplied outputs the signal Sf supplied thereto as a signal Sh in a state delayed by a predetermined time, and the signal Sh is already described. Is supplied to the changeover switch 17 as a changeover control signal.

As described above, in the state where the circuit arrangement shown in FIG. 1 is performing the speed control operation, the position of the focus point focused on the optical disk 1 by the lens 5 of the optical head is the target position. When the (target position) is reached, a changeover control signal is supplied from a control circuit (not shown) to the changeover control signal supply terminal 25, and the movable contact v of the changeover switch 26 described above moves from the fixed contact a side to the fixed contact a. The switch 22 is switched to the b side and the switch control signal is supplied from the control circuit (not shown) to the switch control signal supply terminal 36, and the switch 22 is turned off, so that the circuit arrangement shown in FIG. Near 90 degrees output from the encoder detector 9 in correspondence with the displacement of the carriage 2 (displacement of the objective lens 5 of the optical head) in the state where the control operation is switched to Two signals Sa and Sb from the amplifier 10 which amplifies and outputs the pseudo sine wave two-phase signals Sa and Sb having a phase difference of a predetermined angle within the angles are supplied to the fixed contacts a and b. The changeover switch 15
The signal Si as shown in FIG. 2 (i), that is, the signal Si in a state in which the output signal Sg from the exclusive OR circuit 18 is slightly delayed, is used as a switching control signal, and the above-mentioned signal Si is used. Is in the high level state, the movable contact v is switched to the fixed contact a side, and when the signal Si is in the low level state, the movable contact v is switched to the fixed contact b side. Outputs a signal in a state in which only the linear portions of the above-mentioned two signals Sa and Sb are extracted. The signal is directly supplied to the fixed contact a of the changeover switch 17 and the polarity is inverted by the polarity inverting circuit 16. Is supplied to the fixed contact b of the changeover switch 17 as an inverted signal.

The movable contact v of the changeover switch 17 receives the output signal Sf from the comparison circuit 13 from the delay circuit 2.
When the signal Sh shown in FIG. 2 (h) slightly delayed by 1, that is, the signal Sh used as the switching control signal is at the low level, it is switched to the fixed contact a side and When Sh is in the high level state, the signal is output to the fixed contact b side, so that the signal S output from the movable contact v of the changeover switch 17 is output.
l is as shown in FIG. As described above, the above-mentioned signal Sl is predetermined within the angle of about 90 degrees output from the detector 9 of the encoder corresponding to the displacement of the carriage 2 (displacement of the objective lens 5 of the optical head). Pseudo-sinusoidal two-phase signals Sa, S having an angle phase difference
The linear signal portion in b is extracted, and it is in a state in which it is aligned on the time axis in the same inclination direction.

In the state where the circuit arrangement of FIG. 1 is performing the position control operation, since the switch 22 is in the OFF state as described above, the diagram output from the movable contact v of the changeover switch 17 described above. The signal Sl as shown in (l) of 2 is supplied to the sampling hold circuit 23 through the capacitor C functioning as an AC coupling circuit, so that only the AC component of the signal Sl described above is input to the sampling hold circuit 23. Will be given. As described above, the reference voltage source Vref is connected to the input side of the sampling and holding circuit 23 via the resistor R, and the output signal of the sampling and holding circuit 23 is supplied to the input side of the sampling and holding circuit and the augend signal. It is also connected to the input terminal of the subtraction circuit 24. Therefore, as described above, the AC component of the signal Sl supplied to the input side of the sample hold circuit 23 via the capacitor C functioning as an AC coupling circuit is included in the capacitor C described above.
The direct current component is re-inserted by the circuit of the resistor R, the reference voltage source Vref, and the sample hold circuit.

The sample-and-hold circuit 23 is provided with the signal S output from the pulse generating circuit 19 as described above.
2 (m) corresponding to the low-level state period of j.
During the low level period of Sjm shown in (4), the above-mentioned signal Sl is supplied as a sampled value,
The signal Sj changes from the low level state to the high level state during the high level period of Sjm of FIG. 2 (m) corresponding to the high level state period of the signal Sj. The sampled value of the input signal Sl at the time is maintained. Since the input and output sides of the sample and hold circuit 23 are connected, the signal Sn appearing at the output side of the sample and hold circuit 23 is monotonic in the same direction on the time axis as shown in (n) of FIG. The position signal changes to. In the signal Sn shown in (n) of FIG. 2, the signal portion corresponding to the holding period (hold period) in the sample and hold circuit 23 becomes flat, but in reality, the time length of this holding period portion is long. Is extremely short compared to the sampling period, the signal Sn actually appearing on the output side of the sample and hold circuit 23 is linearly and monotonically changing in the same direction with a certain inclination on the time axis during constant velocity movement. Become a signal.

The voltage of the reference voltage source Vref connected to the sample hold circuit 23 via the resistor R is the converged voltage of the servo system. In addition, the above-mentioned capacitor C and resistor R
The time constant determined by and is set to a sufficiently large time constant for causing the carriage to settle after seeking. Then, the linear range of the position signal can be expanded within the range of the time constant determined by the capacitor C and the resistor R described above. Since the position control device for a movable body of the present invention generates a position signal which linearly changes linearly in the same direction with a certain inclination on the time axis as described above, it is possible to increase the holding force. Become. Therefore, in the position control device for a movable body of the present invention, the carriage can be accurately positioned at the target position (target position) after high-speed seek even if the encoder pitch is small.

[0021]

As is apparent from the above detailed description, in the position control device for a movable body of the present invention, the pseudo sine wave 2 having a phase difference of a predetermined angle within an angle of about 90 degrees is provided. An encoder that generates a phase signal outputs a pseudo-sine wave two-phase signal corresponding to the displacement of the movable body that is the target of position control, and the sum signal of the signals of each phase in the two-phase signal generated by the encoder. And a difference signal are generated. For the sum signal and the difference signal, a binarized signal is generated with the center value of each signal as a threshold value, and the binarized signal of the sum signal and the difference signal One of the signals of each phase in the two-phase signal generated by the encoder is obtained by obtaining the exclusive OR output signal with the binarized signal and corresponding to the signal level of the exclusive OR output signal. Select the phase signal and press Of the selected signal and the signal obtained by reversing the polarity of the selected signal by using the binarized signal of the difference signal as the switching signal. One of the signals is output, the AC component obtained by passing the output signal through the AC coupling circuit is input to the sample hold circuit, and at the time position of each edge in the exclusive OR output signal described above. The signal level of the signal input to the sample hold circuit is held by the sample hold circuit for a predetermined time width from the time position described above, and the output of the sample hold circuit is fed back to the input side to reinsert the predetermined DC component. Since the position signal is obtained in this way, the linear range of the position signal can be expanded within the range of the time constant in the DC re-insertion circuit described above, And as it can generate a position signal that can increase Rudingu force, conventional problems described above, according to the present invention can be satisfactorily solved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment in which a movable body position control device of the present invention is applied to an optical disk recording / reproducing device.

FIG. 2 is a waveform diagram for explaining the operation of the position control device for a movable body of the present invention.

FIG. 3 is a perspective view of a recording / reproducing apparatus for an optical disc shown as an example of the recording / reproducing apparatus.

FIG. 4 is a diagram for explaining a position control operation of a conventional device.

[Explanation of symbols]

M ... Motor for driving and rotating the disc, 1 ... Optical disc, 2 ... Carriage (transport body), 3, 4 ... Guide rod, 5 ...
Lens provided on the optical head, 6 ... Magnetic path of linear motor, 7 ... Driving coil of linear motor, 8 ... Optical scale (linear scale), 9 ... Detector, 10 ... Amplifier,
11, 24, 35 ... Subtraction circuit, 12 ... Addition circuit, 13,
14 ... Comparison circuit, 15, 17, 26, 30, 32 ... Changeover switch, 16, 31 ... Polarity inversion circuit, 18 ... Exclusive OR circuit, 19 ... Pulse generation circuit, 20, 21 ... Delay circuit, 22 ... Switch , 23 ... Sample and hold circuits, 2
7 ... Drive circuit, 28, 29 ... Differentiation circuit, 33 ... Gain setting circuit, 34 ... Reference speed profile generation circuit,

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[Procedure amendment]

[Submission date] December 12, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

According to the present invention, a pseudo-sine wave two-phase signal having a phase difference of a predetermined angle within an angle in the vicinity of 90 degrees corresponds to the displacement of a movable body whose position is to be controlled. Of the two-phase signals generated by the signal generating means, the means for obtaining the sum signal of the signals of the respective phases of the two-phase signals generated by the signal generating means, and the signal of the respective phases of the two-phase signals generated by the signal generating means. A means for obtaining a difference signal; a means for obtaining a binarized signal with respect to the sum signal and the difference signal using the center value of each signal as a threshold; and a binarized signal of the sum signal and the difference signal. Means for obtaining an exclusive OR output signal with the binarized signal, and a signal of one phase of the signals of each phase in the two-phase signal generated by the signal generating means by the exclusive OR output signal Signal selecting means for selecting the The signal switching means for switching and outputting the output signal from the selecting means and the signal obtained by inverting the polarity of the output signal from the signal selecting means as a switching signal of the binarized signal for the difference signal. Means for inputting the AC component of the output signal from the signal switching means to the sample and hold circuit, and the signal level of the signal input to the sample and hold circuit at the time position of each edge in the exclusive OR output signal, There is provided a position control device for a movable body, which comprises means for feeding back an output of a sample hold circuit for holding for a predetermined time width from the above-mentioned time position to re-insert a predetermined DC component. ..

Claims (1)

Claim: What is claimed is: 1. A pseudo-sine wave two-phase signal having a phase difference of a predetermined angle within an angle in the vicinity of 90 degrees is corresponded to a displacement of a movable body which is an object of position control. Of the two-phase signals generated by the signal generating means, the difference between the signals of the respective phases of the two-phase signals generated by the signal generating means, A means for obtaining a signal, a means for obtaining a binarized signal for the sum signal and the difference signal by using the center value of each signal as a threshold, and a binarized signal of the sum signal and the difference signal described above.
A means for obtaining an exclusive OR output signal with the binarized signal, and a signal of one phase of the signals of each phase in the two-phase signal generated by the signal generating means by the exclusive OR output signal. The signal selecting means to be selected, the output signal from the signal selecting means, and the signal obtained by inverting the polarity of the output signal from the signal selecting means are switched as the binarized signal for the difference signal as a switching signal. Of the signal input to the time position of each edge in the exclusive OR output signal described above. A means for feeding back the output of the sample hold circuit, which holds the signal level from the above-mentioned time position for a predetermined time width, to the input side and re-inserting a predetermined DC component. Position control device for Ranaru movable body.