JPS60164962A - Rotation controlling device of motor - Google Patents

Abstract

PURPOSE:To ensure stable rotation by rotating by inertia of a motor even when servo of the motor is made off by omission of information due to the dust adhered on a disk, and constituting a servo loop immediately when the information is detected again. CONSTITUTION:The first speed controlling loop is made up of a motor 1, a pickup device 3, a longest period detecting circuit 6 and a motor driving circuit 9. Further, the second speed controlling loop (phase controlling loop) is formed of above-mentioned motor 1, pickup device 3, a clock extracting circuit 7, a phase comparator circuit 8 and the motor driving circuit 9. A drop-out detecting circuit 4 generates a fixed width pulse for a fixed time taup from the time of starting of drop-out taud. As the longest period detecting circuit 6 has a large time constant, the motor 1 is rotated only by inertia, and does not go into unconrtollable running. As the width of drop-out taud is 1-2mS in larger one, drop DELTAN of rotation is very small, and the clock extracting circuit 7 operates at once, and it is possible to proceed to the second speed control loop operation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is mainly applicable to digital audio disc players (compact disc players) and video disc players.
The present invention relates to a motor rotation control device that can be used in disc players and the like.

Conventional configuration and its problems Normally, in digital audio disc players, etc., the rotational position information of the motor recorded on the disc is compared with a rotational reference phase signal to obtain a rotational error signal and perform phase control. However, in order to detect the rotational phase information recorded on the disk, it is first necessary to keep the rotational speed of the motor within a predetermined range. However, normally, the range of rotational speeds in which rotational phase information of the disk can be detected is relatively narrow, being within a number of normal rotational speeds. That is, it is necessary to control the rotational speed of the disk by another means to reach a rotational speed at which rotational phase information can be detected. Usually, the number of polarity inversions of the signal recorded on the disk is detected and converted to voltage, and this is used as speed information to roughly control the rotation speed, or the longest period of the signal recorded on the disk is used as the voltage. There is a method of roughly controlling the number of revolutions by converting and holding the data and using it as speed information.

That is, before establishing the phase control loop, it is necessary to perform a pull-in operation in a speed control loop for coarse control using the longest period information and the like as speed error information, which has been fully explained. In these methods, if the disk information is lost due to dust on the disk or scratches on the information surface, the pink amplifier means will no longer be able to detect motor rotation information and the phase control loop will be disconnected. Switches to the speed control loop for coarse control. However, due to the lack of disk information, not only the two-phase information but also the speed information is missing, so the control loop cannot be stably controlled.
The rotation of the motor is greatly disturbed.

There have been problems in that it takes a very long time to return to the original stable phase control state after the disc information is no longer missing, that is, after the output of the pickup means has become normal. 0 Purpose of the Invention The purpose of the present invention is that even if information is lost due to dust attached to the disk and the servo of the motor is disconnected, the servo loop is immediately reconfigured as soon as information is detected again. An object of the present invention is to provide a rotation control device for a motor that can ensure stable rotation.・Structure of the Invention The motor rotation control device of the present invention includes a motor that drives a disk on which information is recorded in a spiral shape, a Vinocqua that detects the information recorded on the disk, a knob means, and a detection means for picking up the motor. a speed detection means for detecting rotational speed information included in the signal; a clock extraction means for extracting a rotation synchronized clock signal of the motor included in the detection signal of the pickup means; and an output signal of the clock extraction means and an external rotation reference. a phase comparison means for generating a phase error by comparing the phase with a clock signal; and a motor drive means for converting the output signal of the speed detection means or the phase comparison means into voltage or current and supplying electric power to the motor. and the pickup means.

information is being detected, but when the clock extraction means does not extract a correct clock signal, a first speed control loop is formed including the motor, the pinocanog means, the speed detection means, and the motor drive means. , the pink amplifier means detects information.

And when the clock extracting means extracts a correct clock signal, a second clock signal including the motor, a pink-up means, a clock extracting means 2, a phase comparing means, and a motor driving means is activated.
is configured to form a speed control loop of
When the information from the disk is missing, detect the information missing and open the first speed control loop for a certain period of time from the time when the information is detected, or when the information from the disk is missing, the first speed control loop is opened. The first speed control loop is configured to open from the time when the detection of the missing part is started until a certain period of time has elapsed after the detection of the missing part has been completed. Information may be lost due to dust etc.

As a result, even if the servo comes off, the motor rotation will not be disturbed.
As soon as the information is detected again, Zarborug is formed and stable rotation can be ensured.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an overall block diagram of an embodiment of the present invention.

In FIG. 1, 1 is a motor that rotates a disk 2;
3 is a pickup means for reading information on the disc 2; Reference numeral 4 denotes a dropout detection circuit, which generates a pulse of a certain time width when the output of the pickup means 3 is lost, and opens the Suinochiro for a certain period of time.

Reference numeral 6 denotes a longest period detection circuit for detecting the longest period pulse in the output signal of the pickup means 3 and converting it into a voltage, and is usually composed of a peak value hold circuit or the like. Reference numeral 7 denotes a clock extraction circuit, which normally operates to extract the motor rotation synchronization clock signal contained in the information recorded on the disk 2 when the disk 2 enters a predetermined rotational speed range. . 8 is the rotation reference clock signal fB
This is a phase comparison circuit that compares the phases of the output signal of the clock extraction circuit 7 and the phase of the output signal of the clock extraction circuit 7, and generates a voltage corresponding to the phase error.

Reference numeral 9 denotes a motor drive circuit that receives a rotation error signal from one of the longest cycle detection circuit 62 and the phase comparison circuit 8 and supplies current to the motor 1.

Reference numeral 10 denotes an operation status determining circuit for controlling the switch 11 according to the output status of the pickup means 3 and the status of the clock extraction operation of the clock extraction circuit 7.

Above motor 1. Pick-up means 3. Longest period detection circuit 6. The motor drive circuit 9 forms a first speed control loop, and the motor 1. Pick-up means 3. A second speed control loop (phase control loop) is formed by a clock extraction circuit 72, a phase comparison circuit 8, and a motor drive circuit 9.

FIG. 2(a) shows an example of the configuration of the longest period detection circuit 6, with 20
．． 21 is a resistor 22. A resistor and a transistor constitute a switch that turns on and off a charge circuit including a capacitor 23. 24 and 25 are operational amplifiers and diodes constituting a peak level detector that detects the maximum value of the input level; 26 and 27 are capacitors and resistors for holding the peak level for a certain period of time with appropriate attenuation characteristics; 28 is a voltage follower circuit constituting a buffer.

Figure 2 (bl) is a time chart showing the waveforms of each terminal in Figure 2 (a). The output voltage changes depending on the period of the "L" level of the input (2), and the output voltage changes when the peak is held. show.

In FIG. 1, the operation in a normal servo state without dropout, that is, in a state where the switch 5 is closed, will be explained. When the motor 1 starts rotating in response to an external motor start command (the start circuit is not shown),
The pickup means 3 starts detecting rotation information from the disk 2 according to the number of rotations of the motor 1. At this point, the rotation speed is so low that the clock extraction circuit 7 does not operate and the clock signal cannot be extracted normally.The state determination circuit 10 detects this state and switches the switch 11 to state, the longest period detection circuit 6 detects the longest period in the output signal of the pickup means 3, forms a first speed control loop using it as speed information, and detects the longest period in the output signal of the pickup means 3. The longest period is the specified period (Ladle 2, 6
511S). As a result, through the first speed control loop described in "-", the motor 1 reaches a rotational speed at which the clock extraction circuit 7 is normal and a lock extraction signal can be output, and the state determination circuit 1 detects this and switches the 11 to b to form a second speed control loop, ie a phase control loop, to reach a steady state.

FIG. 3 is a time chart for detailed explanation of the present invention when a dropout occurs, in which (8) is the output of the pickup means 3, (B) is the output of the dropout detection circuit 4, and (q is the longest The output of the period detection circuit 6, 0, is the input of the motor drive circuit 9, (the slope indicates the rotation state of the motor 1.

In the third diagram, if drosogage-out of τd occurs, the dropout detection circuit 4 generates a constant width pulse for a fixed time τ from the start of τd, as shown in FIG. 3(B).

At this time, since the output of the pink-up means 3 has disappeared, the clock extraction circuit 7 cannot operate, and the state determination circuit 1o
detects this state and switches the switch 11 from b to a. At this time, the longest period detection circuit 6 erroneously detects the dropout period τd as the longest period, and generates a very large acceleration error command output ■K as shown in FIG. As explained in Fig. 2(a), since the hold capacitor 26 and the discharge resistor 27 have a large time constant, the acceleration signal generated due to the false detection is It takes a long time (τ8) until the influence disappears.For this reason, the dropout detection circuit 4
τ as shown in Figure 3 p).

A constant width pulse with a larger width τ2 is generated, and the output thereof opens the switch 6 and cuts off the acceleration command input to the motor drive circuit 9. Therefore, during the period τ2, motor 1
rotates solely due to inertia, and never runs out of control. The decrease ΔN in the rotation of the motor 1 at this time is caused by losses in the shaft and other parts of the motor itself, but normally the dropout width τd is large and is about 1 to 2 m3, so the time τ2 for opening the switch 5 is set to 5. If it is set to ~10 times, the drop ΔN per revolution is very small,
Immediately at that point, the clock extraction circuit 7 can operate and enter the second speed control loop operation.

If there is no dropout detection circuit 4 in the above configuration, or if it does not operate, it is assumed that there is a dropout as shown in Figure 3 (
An acceleration pulse as shown in q is generated, and the motor 1 is sped up significantly from its original rotation speed, and when the effect of dropout disappears as shown by the dashed line in Fig. 3(E), Even when attempting to perform a clock extraction operation, the rotation has deviated too much from ΔM, so the first speed control loop is first formed, and then the second speed control loop is formed to enter normal operation. It is necessary to perform step-by-step operations. Therefore, even a small dropout will cause a large disturbance in rotation.

FIG. 4 is a block diagram showing another example of the configuration of the dropout detection circuit 4. 31 is a dropout width detection circuit that generates a pulse of "Hn level" with a width corresponding to the dropout width, and its output generates a pulse of "H" level for a certain period of time τ9 from the falling edge of the output. The output of the constant-width nodalus generating circuit 32 and the OR circuit 33 are combined to form a dropout detection output.

FIG. 6 is a signal waveform diagram of each part when using the dropout detection circuit shown in FIG. ) The only difference is how the waveforms are generated; everything else is the same.

The explanation here will be omitted. According to the operation shown in FIG. 5, regardless of the size of the dropout width, the time τ9 required to avoid the adverse influence of the peak hold circuit is constant, so that influence can always be avoided stably.

Effects of the Invention As is clear from the above explanation, the motor rotation control device of the present invention is capable of detecting information again without disrupting the rotation even if information is lost due to dust attached to the disk and the motor servo is missed. It has an excellent feature that, when it is completed, a second speed control loop (phase control loop) can be immediately formed without passing through the first speed control loop to ensure stable rotation.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the motor rotation control device of the present invention, and Fig. 2 (a) and (b) show an example of the configuration of the longest cycle detection circuit used in the embodiment of the present invention and its operation. 3 is a time chart for explaining the operation of each part of the control system of the embodiment of the present invention when a dropout occurs, and FIG. 4 is a time chart for explaining other parts of the dropout detection circuit. A block diagram showing an example of the configuration, FIG. 6 is a time chart of each part of the control system when the dropout detection circuit of FIG. 4 is used. 1...Motor, 2...Disc, 3...
...Pick amplifier means, 4...Dropout detection circuit, 6゜11...Switch, 6...
...Longest period detection circuit, 7・Clock extraction circuit, 8
・・・Phase comparison circuit, 9・Motor drive circuit, 10...
Status determination circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure (Q) I tb+ Figure 3 1d. I (DJ -11111---□ 1 Figure L J

Claims (3)

[Claims] (1) A motor that drives a disk on which information is recorded in a spiral, a pickup means that detects the information recorded on the disk, and a detection signal of the pick amplifier means.
speed detection means for detecting rotational speed information detected by the pickup means; phase comparison means for generating a phase error by comparing the phase of the detection signal of the pickup means with a rotation reference clock signal; The pickup means detects information, and the pick-up means detects information, and the extraction means detects the correct clock signal. When it is time to extract, the first motor including the motor, pickup means, speed detection means, and motor drive means
forming a speed control loop, the pickup means comprising:
Detect information. and when the clock extraction means extracts a correct clock signal, a second speed control loop is formed including the motor, the pickup means, the clock extraction means, the phase comparison means, and the motor drive means; , when the information ゛ from the disk is missing, the missing information is detected, and the first speed control loop is opened for a certain period of time from the time when the missing information is detected. Rotation control device. (2) When information is missing from the disk, the first speed control loop is opened from the time when detection of the missing information starts until a certain period of time has passed after the detection of the missing information has finished. Claim No. (1) characterized by
A rotation control device for a motor as described in . (3) The speed error detection means includes a longest period detection circuit that detects the longest period component in the detection signal of the pickup means and converts it into voltage or current. The motor rotation control device according to item 1) or item (2).