JPH0877697A - Disk motor controller - Google Patents

Abstract

(57) [Summary] [Object] The present invention changes the drive torque generated in the disk motor between the case of accelerating and the case of decelerating, so that the disk and the head can be separated from each other after the track jump to the inner and outer circumference sides of the disk. An object of the present invention is to provide a disk motor control device capable of controlling the time required for the relative speed to reach a constant value. [Structure] The rotation speed of the disk motor is controlled when the rotation speed of the disk motor is controlled so that the relative speed between the head and the disk becomes constant during and after the high-speed movement of the head by the track jump. The drive torque generated in the disk motor is controlled to be smaller when the rotational speed of the disk motor is controlled to be decelerated than when the disk motor is controlled to be accelerated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive system for recording / reproducing digital data on / from a rotationally driven disk, and more particularly to a disk motor controller for controlling the rotational torque of the disk motor.

[0002]

2. Description of the Related Art As is well known, in a disk drive system such as the one described above, digital data that has been subjected to predetermined data processing such as error correction processing and modulation processing is formed on a disk by an optical head. By writing along the track that is recorded, the digital data can be recorded on the disc, or the digital data recorded on the disc is read by the optical head, and error correction processing and demodulation are performed on the read digital data. There is a device that reproduces digital data from a disc by performing a predetermined data process such as a process.

By the way, in the case of a method of recording digital data along a track of a disk so that the recording density becomes constant, the disk drive system may include a disk and an optical head regardless of the recording side and the reproducing side. To keep the relative velocity constant, that is, CLV (constant linear velocity)
It is necessary to control the rotation speed of the disc by the method. For example, in the CD (Compact Disc) system, when the optical head is moved from the inner circumference side to the outer circumference side of the disc, the rotation speed of the disc is controlled to 500 to 200 rpm.

On the other hand, the disk drive system as described above has a so-called track jump function for moving the optical head at a high speed in the radial direction of the disk toward a target position, as in a high speed search operation on the reproducing side. Has been. Then, in the disk drive system, by controlling the rotation speed of the disk so that the relative speed between the disk and the optical head becomes a constant value while the optical head has reached the target position by the track jump. It enables quick reading of digital data.

FIG. 4 shows a CLV servo means for controlling the rotational speed of the disk so that the relative speed between the disk and the optical head becomes a constant value. That is,
Reference numeral 11 is a disk, which is rotated by a disk motor 12 at a desired rotation speed. An optical head 13 for reading digital data recorded on the disk 11 is provided on the signal recording surface side of the disk 11, that is, on the lower surface side in the drawing, in the radial direction of the disk 11, that is, in the direction indicated by arrows A and B in the drawing. It is movably supported.

Here, in a state where the optical head 13 reaches a target position by a track jump and is stopped, first, the digital data read from the optical head 13 is supplied to the synchronizing signal extracting circuit 14, The sync signal component is extracted. The sync signal component extracted by the sync signal extraction circuit 14 is supplied to one input end of the frequency comparison circuit 15. A reference signal having a constant frequency output from the reference signal generation circuit 16 is supplied to the other input terminal of the frequency comparison circuit 15.

The frequency comparison circuit 15 includes a synchronizing signal extracted by the synchronizing signal extracting circuit 14 and the reference signal generating circuit 1.
The reference signal output from 6 is compared in frequency, and a torque control signal corresponding to the frequency difference component is generated. The torque control signal output from the frequency comparison circuit 15 is supplied to the power amplification circuit 17, converted into a motor drive signal, and supplied to the disk motor 12, so that the frequency of the synchronization signal is the frequency of the reference signal. The rotation speed of the disk 11 is controlled so that

Thereafter, the digital data read by the optical head 13 is supplied to the signal processing circuit 18 and subjected to predetermined data processing such as error correction processing and demodulation processing, so that the data is read from the target position of the disk 11. The reproduced digital data is taken out from the output terminal 19.

In short, no matter which position the optical head 13 is moved by the track jump, the frequency of the sync signal extracted from the digital data read at that position matches the frequency of the reference signal so that the disc motor is driven. By controlling the rotation speed of 12, the rotation speed of the disk 11 is controlled so that the relative speed between the disk 11 and the optical head 13 becomes a constant value.

By the way, as described above, the optical head 1
When the rotational speed of the disk motor 12 is controlled so that the relative speed between the disk 11 and the optical head 13 becomes a constant value in a state in which the disk 3 reaches the target position by the track jump and is stopped, the optical head 13 is the disk 11
When the disc is moved from the inner side to the outer side,
When the optical head 13 is moved from the outer peripheral side to the inner peripheral side of the disk 11 by controlling the rotation of the disk motor 12 so as to reduce the rotational speed of the disk 1, the disk 11 is accelerated so as to accelerate the rotational speed of the disk 11. The rotation speed of the motor 12 will be controlled.

Controlling the rotational speed of the disk motor 12 means changing the motor drive signal output from the power amplifier circuit 17 to change the disk speed regardless of whether the disk motor 12 is accelerated or decelerated. That is, a drive torque is generated in the motor 12 to change its rotation speed.

Here, the disc motor 12 has a friction torque generated by its own structure and the disc 11
Since the friction torque of a turntable (not shown) that supports the motor is applied, the rotation speed is, for example, 350 rpm to 400 rpm.
Compared with the case of accelerating to rpm, the rotation speed is 400r
50rpm is the same as decelerating from pm to 350rpm
Even when changing the rotation speed by the amount of m,
The drive torque generated by the disk motor 12 to change its rotation speed can be reduced.

However, the conventional disk motor 12
In the case of acceleration, the control means controls the rotational speed by generating a drive torque of the same magnitude in the disk motor 12 when the disk 11 is accelerated by the same amount and when it is decelerated by the same amount. The time required for the relative speed between the disk 11 and the optical head 13 to reach a constant value differs between the case of "and deceleration".

That is, considering the case where the optical head 13 is moved to the inner circumference side of the disk 11 by the same distance by the track jump and the case where it is moved to the outer circumference side,
The time required until the relative speed between the disk 11 and the optical head 13 reaches a constant value after the movement is
Is moved to the outer peripheral side of the disk 11 to decelerate the disk motor 12, which is shorter than the case where the optical head 13 is moved to the inner peripheral side of the disk 11 to accelerate the disk motor 12, There will be variations in the high-speed search time.

The sync signal is not correctly detected during the track jump. In this case, in the case of the CD format, for example, of the signal components obtained from the optical head 13, the longest period of 11T is obtained by means (not shown) in place of the synchronization signal extraction circuit 14 in FIG.
Only the component (T is the period of the bit synchronization clock) is extracted, and the synchronization signal is replaced with this component.
Therefore, even during the track jump, the disk motor 12 can be controlled so that the relative speed between the disk 11 and the optical head 13 becomes a substantially constant value. Therefore, the gist of the present invention can be applied even during the track jump.

[0016]

As described above, in the conventional disk motor control means, in order to control the rotation speed of the disk motor, the drive torque generated in the disk motor should be decelerated rather than accelerated. Since the number is small, there is a problem in that the time required for the relative speed between the disk and the head to reach a constant value varies depending on whether the head is accelerated or decelerated by the same distance.

Therefore, the present invention has been made in consideration of the above circumstances, and the drive torque generated in the disk motor is changed depending on whether the disk motor is accelerated or decelerated, so that the disk inner peripheral side and the disk outer peripheral side are changed. An object of the present invention is to provide a very good disk motor control device capable of controlling the time required for the relative speed between the disk and the head to reach a constant value after a track jump.

[0018]

DISCLOSURE OF THE INVENTION A disk motor controller according to the present invention records or reproduces data on or from a disk, a disk motor that rotationally drives the disk, and a disk that is rotationally driven by the disk motor. Head, a servo means for controlling the rotation speed of the disk motor so that the relative speed between the head and the disk becomes constant, a track jump means for moving the head at a high speed in the radial direction of the disk, and a track jump means. When the rotation speed of the disk motor is controlled so that the relative speed between the head and the disk becomes constant by the servo means during and after the high speed movement of the head by the operation of the disk motor, the rotation speed of the disk motor accelerates. The rotation speed of the disk motor is slower than when it is controlled in the following direction. Write if you controlled is obtained by such a control means for controlling so as to reduce the driving torque to be generated in the disk motor.

[0019]

According to the above construction, when the rotational speed of the disk motor is controlled so that the relative speed between the head and the disk becomes constant, the rotational speed of the disk motor is controlled to be accelerated. The drive torque generated in the disk motor is controlled to be smaller when the rotation speed of the disk motor is controlled than in the case where the rotation speed of the disk motor is reduced. It is possible to control the time required for the relative speed between the disk and the head to reach a constant value after the track jump to the side.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1, the same parts as those in FIG. 4 are designated by the same reference numerals. That is, a part of the motor drive signal output from the power amplification circuit 17 is
It is supplied to the level detection circuit 20. The level detection circuit 20 detects a current value flowing through the disk motor 12 based on the input motor drive signal, and outputs a voltage level corresponding to the current value to one input terminal of the level comparison circuit 21. There is.

On the other hand, the torque control signal output from the frequency comparison circuit 15 is supplied to the power amplification circuit 17 and the torque direction determination circuit 22. The torque direction determination circuit 22 determines, based on the input torque control signal, whether the disk motor 12 is controlled to accelerate or decelerate, and a determination corresponding to the determination result. The signal is output to the reference level generation circuit 23. This reference level generation circuit 23
Selectively outputs the first reference level and the second reference level different from the first reference level to the other input end of the level comparison circuit 21 based on the input discrimination signal. .

Here, the level comparison circuit 21 compares the voltage level output from the level detection circuit 20 with the first or second reference level output from the reference level generation circuit 23, and the level is compared. The torque limiting signal corresponding to the difference is output to the current limiting circuit 24. In this case, the level difference between the voltage level output from the level detection circuit 20 and the first reference level is smaller than the level difference between the voltage level output from the level detection circuit 20 and the second reference level. Is set to. Then, the current limiting circuit 24 limits the drive torque generated in the disk motor 12 by controlling the motor drive signal output from the power amplifier circuit 17 based on the input torque limit signal.

In the above configuration, if the optical head 13 is track-jumped in the inner peripheral direction of the disk 11 and stopped, a power drive circuit 17 outputs a motor drive signal for accelerating the rotational speed of the disk motor 12. Generated, and based on this, drive torque is generated in the disk motor 12 to accelerate its rotation speed. At this time, the torque direction determination circuit 22 generates a determination signal indicating that the optical head 13 has been moved in the inner peripheral direction of the disk 11, and the reference level generation circuit 2
From 3, the first reference level is generated.

Then, the level comparison circuit 21 compares the voltage level output from the level detection circuit 20 with the first reference level and outputs a torque limit signal corresponding to the level difference to the current limit circuit 24. However, based on the output of the current limiting circuit 24, the motor drive signal output from the power amplification circuit 17 is limited, so that the drive torque of the disk motor 12 is limited. However, the level comparison circuit 21 Is outputting the torque limit signal corresponding to the level difference between the voltage level output from the level detection circuit 20 and the first reference level, the current limit circuit 24
There is almost no limitation on the motor drive signal output from the power amplification circuit 17 according to the above, and the disk motor 12 is accelerated by the drive torque as in the conventional case.

On the other hand, if the optical head 13 is track-jumped in the outer peripheral direction of the disk 11 and stopped, the power amplifier circuit 17 generates a motor drive signal for decelerating the rotational speed of the disk motor 12, and based on this signal. As a result, a drive torque that reduces the rotation speed of the disk motor 12 is generated. At this time, the torque direction determination circuit 22 generates a determination signal indicating that the optical head 13 has been moved in the outer peripheral direction of the disk 11, and the reference level generation circuit 23 outputs the second reference level. Has been generated.

Then, the level comparison circuit 21 compares the voltage level output from the level detection circuit 20 with the second reference level, and outputs a torque limit signal corresponding to the level difference to the current limit circuit 24. However, based on the output of the current limiting circuit 24, the motor drive signal output from the power amplification circuit 17 is limited, so that the drive torque of the disk motor 12 is limited. However, the level comparison circuit 21 Is outputting the torque limit signal corresponding to the level difference between the voltage level output from the level detection circuit 20 and the second reference level, the current limit circuit 24
As a result, the motor drive signal output from the power amplifier circuit 17 is limited, and the disk motor 12 is decelerated with a drive torque that is more suppressed than in the conventional case.

Therefore, according to the structure of the above-described embodiment, when the optical head 13 is track-jumped in the inner peripheral direction of the disk 11 to accelerate the disk motor 12, the disk motor 12 is driven in a conventional manner. When the optical head 13 is accelerated by the driving torque and the optical head 13 is track-jumped in the outer peripheral direction of the disk 11 to decelerate the disk motor 12, the optical head 13 is decelerated by the driving torque suppressed as compared with the acceleration. Regardless of whether the optical disk 13 is moved to the outer peripheral side or the inner peripheral side of the disk 11, the time required for the relative speed between the disk 11 and the optical head 13 to reach a constant value after the movement of the optical head 13 is , Can be controlled to be substantially equal.

FIG. 2 shows the details of the power amplifier circuit 17, the level detection circuit 20, the level comparison circuit 21, the torque direction determination circuit 22, the reference level generation circuit and the current limit circuit 24 shown in FIG. There is. That is, the input terminal 2
A torque control signal output from the frequency comparison circuit 15 is supplied to the circuit 5. This torque control signal is positive on the ground level when the disk motor 12 is accelerated, and represents the magnitude of acceleration as a level, and negative on the ground level when the disk motor 12 is decelerated. It shows the magnitude of speed in terms of levels.

A reference level (+ B / 2 level in this case) for determining the polarity and level of the torque control signal is applied to the input terminal 26. The torque control signal and the reference level supplied to the input terminals 25 and 26 are the resistances R1 to R6 and the transistors Q1 to
A power amplification circuit 17 including Q4 and operational amplifiers OP1 and OP2 converts it into a motor drive signal for rotating the disk motor 12 in a forward direction (acceleration direction) or a reverse direction (deceleration direction) at a predetermined rotation speed. , Are supplied to the disk motor 12.

In this case, a current flows through the transistor Q1, the disk motor 12, and the transistor Q4, so that the disk motor 12 is rotationally driven in the positive direction (acceleration direction) with a torque according to the current value, and the transistor Q3 and the disk motor 12 are driven. Also, it is assumed that the disk motor 12 is rotationally driven in the reverse direction (deceleration direction) with a torque according to the current value due to the current flowing through the transistor Q2.
The value of the current flowing through the disk motor 12 is converted into a voltage level by the resistor R7 that constitutes the level detection circuit 20, and the operational amplifier OP that constitutes the level comparison circuit 21.
3 is applied to the non-inverting input terminal +.

On the other hand, the torque control signal and the reference level supplied to the input terminals 25 and 26 are supplied to the inverting input terminal − and the non-inverting input terminal + of the operational amplifier OP4 constituting the torque direction discriminating circuit 22, respectively. By comparing the levels, a determination signal corresponding to the moving direction of the optical head 13 is generated. In this case, the discriminating signal has a negative polarity when the disk motor 12 is controlled to accelerate, that is, when the torque control signal has a positive polarity with respect to the reference level. When it is controlled to decelerate, that is, when the torque control signal has a negative polarity with respect to the reference level, it has a positive polarity.

Then, the discrimination signal output from the operational amplifier OP4 is supplied to the reference level generating circuit 23 including the resistors R8 to R11 and the transistor Q5. In the reference level generation circuit 23, the transistor Q5 is turned off when the determination signal having the negative polarity is supplied, so that the first reference level is generated across the resistor R11.
When the determination signal having the positive polarity is supplied, the transistor Q5 is turned on, so that the resistor R9 acts so that the second terminal lower than the first reference level is applied across the resistor R11.
The reference level of is generated.

Here, the first or second reference level output from the reference level generating circuit 23 is applied to the inverting input terminal-of the operational amplifier OP3 constituting the level comparing circuit 21. The operational amplifier OP3 compares the voltage level output from the level detection circuit 20 corresponding to the current value flowing in the disk motor 12 with the first or second reference level output from the reference level generation circuit 23. , A torque limit signal corresponding to the level difference is generated.

Thereafter, the torque limiting signal output from the operational amplifier OP3 is supplied to the current limiting circuit 24 including the resistor R12 and the transistor Q6 via the changeover switch 27 which is normally controlled to change to the illustrated state. . This current limiting circuit 24 is based on the torque limiting signal output from the operational amplifier OP3, and the power amplifying circuit 17
By controlling the current supplied to the disk motor 12
The current flowing to the disk motor 12 is limited to suppress the drive torque of the disk motor 12. The suppression of the drive torque for the disk motor 12 is controlled so as to be stronger during deceleration than during acceleration.

When the changeover switch 27 is controlled to be in a state opposite to that shown in the drawing, the transistor Q6 constituting the current limiting circuit 24 is turned on, so that the current limiting circuit 24 is instructed to the power amplifier circuit 17. Control is not performed at all. Therefore, the disk motor 12
Will be directly driven by the motor drive signal generated by the power amplifier circuit 17. The changeover switch 27 is controlled to be changed over by the changeover signal generated by the user's operation being supplied through the input terminal 28. That is, the changeover switch 27 can be switch-controlled by the user as needed.

Now, description will be made regarding the provision of a state in which the current limiting circuit 24 does not control the power amplification circuit 17 at all by controlling the switching of the changeover switch 27 to a state opposite to that shown in the drawing. That is, the disc motor 1
When 2 is a brushed motor, clogging of the commutator exists as a particular problem. When the commutator is clogged, the impedance between the terminals of the motor becomes small and the generated torque decreases, and in extreme cases, the torque disappears and the impedance between the terminals of the motor approaches zero.

By the way, since most of the cause of the clogging of the commutator is carbon, it can be burnt out by passing a large current between the terminals of the motor. However, the power amplifier circuit 17 always keeps the current limiting circuit 24
Under the control of, the large current cannot flow between the terminals of the disk motor 12. Therefore, the changeover switch 27 sets the state in which the current limiting circuit 24 does not control the power amplification circuit 17 at all, so that the terminal of the disk motor 12 is considered in consideration of a case where the commutator is clogged. It allows a large current to flow between them.

As a method of limiting the drive torque of the disk motor 12, current limitation is performed at the time of starting and voltage limitation is performed after the starting, and current limitation is performed during the track jump of the optical head 13. It is conceivable that the voltage is limited after the jump is completed, or that the current is limited when it is assumed that the rotational speed has become lower than or equal to a predetermined rotation speed during deceleration. On the contrary, if the rotation speed becomes slower than the predetermined value during the normal reproduction or becomes too slow to reproduce the disk 11, the torque limitation may be omitted.

Here, for example, in a disc drive system for reproducing a CD-ROM (Read Only Memory) disc or the like, a 1 × speed reproduction mode for reading audio data recorded on the disc 11 is provided, A double speed reproduction mode for reading other data recorded on the disk 11 at high speed is prepared.

Of these, in the 1 × speed reproduction mode,
The rotational speeds of the disk 11 when reproducing the inner and outer circumferences are about 500 rpm and 2 respectively, as described above.
00 rpm and the difference is 300 rpm. Further, in the double speed reproduction mode, the rotation speed of the disk 11 when reproducing the inner circumference side and the outer circumference side is 1 respectively.
Approximately 1000 rpm and 400r, double the speed of double speed playback mode
pm and the difference is 600 rpm.

In the 1 × speed and 2 × speed reproduction modes, there are two types of frequencies of the reference signal generated from the reference signal generating circuit 16 corresponding to the 1 × speed and 2 × speed reproduction modes. It can be realized by preparing and selectively switching and using according to a designated mode.

Therefore, when the optical head 13 is jumped from the inner circumference side to the outer circumference side or from the outer circumference side to the inner circumference side of the disk 11 by the high speed search operation, the disk motor 12 is in the 1 × speed reproduction mode. 300 rp
m, it becomes necessary to correct the rotational speed difference of 600 rpm in the double speed reproduction mode. In other words, if it is attempted to correct the rotational speed difference of the disk 11 in the same speed in the 1 × speed reproduction mode and the 2 × speed reproduction mode, the 2 × speed reproduction mode will result in the 1 × speed reproduction mode. It is necessary to generate twice the driving torque in the disk motor 12.

Therefore, as shown in FIG. 3, the discrimination signal output from the torque direction discrimination circuit 22 is supplied through the input terminal 29, and the common connection point of the resistors R9 to R11 forming the reference level generation circuit 23 is connected. And a voltage level output from the level detection circuit 20 is supplied to the non-inverting input terminal + via the input terminal 30 and the inverting input terminal − of the operational amplifier OP3 forming the level comparison circuit 21. R1
It is conceivable to interpose the rotation speed control circuit 31 composed of 4, R15 and the transistor Q7.

This rotation speed control circuit 31 has an input terminal 3
By controlling the transistor Q7 to be in the ON state or the OFF state in accordance with the reproduction mode switching signal supplied to 2,
Level control is performed on each of the first and second reference levels output from the reference level generation circuit 23.
Therefore, from the operational amplifier OP3, there are four types of torque limit signals for accelerating or decelerating the disk motor 12 in the 1 × speed reproduction mode and for accelerating or decelerating the disk motor 12 in the 2 × speed reproduction mode. It is generated and output to the changeover switch 27 via the output terminal 33.

In this case, in the 1 × speed and 2 × speed reproduction modes, the drive torque generated in the disk motor 12 is controlled to be suppressed more when the disk motor 12 is decelerated than when it is accelerated. It Further, compared with the case of accelerating or decelerating the disk motor 12 in the 1x speed reproduction mode, the case of accelerating or decelerating the disk motor 12 in the 2x speed reproduction mode is
The drive torque generated in the disk motor 12 is increased. That is, the reproduction mode switching signal supplied to the input terminal 32 is controlled so that the transistor Q7 is turned on in the 1 × speed reproduction mode and the transistor Q7 is turned off in the 2 × speed reproduction mode.

In particular, when the optical head 13 jumps a track on the disk 11 by the same distance, if the rotational speed of the disk motor 12 is controlled at the same time in the 1 × speed reproduction mode and the 2 × speed reproduction mode, This is because the range in which the rotation speed is changed is larger during the double speed reproduction, and thus it is necessary to generate a larger drive torque than during the single speed reproduction.

In particular, the time required for the optical head 13 to make a track jump is designed to be the same regardless of the 1 × speed reproduction mode and the 2 × speed reproduction mode if the distance is the same. The speed of the high-speed search operation is determined by the time required for the optical head 13 to make a track jump or the time required for controlling the rotational speed of the disk 11, whichever is slower.

Therefore, in order to perform a high speed search operation quickly, when the optical head 13 jumps a track on the disk 11 by the same distance, the same time is required for the 1 × speed reproduction mode and the 2 × speed reproduction mode. And disk motor 1
It is desirable that the rotational speed of 2 is controlled. Therefore, when the disk motor 12 is accelerated or decelerated in the double speed reproduction mode as compared to the single speed reproduction mode, the drive torque generated in the disk motor 12 is generated. I try to make it bigger.

Further, when the disk motor 12 is accelerated or decelerated in the 1 × speed reproduction mode with the optimum drive torque for accelerating or decelerating the disk motor 12 in the 2 × speed reproduction mode, it is necessary for the disk motor 12. The drive torque described above is generated, which causes a problem that unnecessary vibration occurs in the disk motor 12. Therefore, in the 1 × speed reproduction mode, the drive torque generated in the disk motor 12 for accelerating or decelerating the disk motor 12 needs to be suppressed as compared with the 2 × speed reproduction mode.

Next, for example, there are CD type discs 11 having a diameter of 8 cm and a disc type having a diameter of 12 cm. In the disc drive system, discs 11 of any diameter are selectively mounted. There are things you can play with. The small-diameter disk 11 and the large-diameter disk 11 have different inertial masses due to differences in size, mass, material, or the like. In this case, the drive torque generated in the disk motor 12 is made larger when the disk 11 having a large inertial mass is accelerated or decelerated than when the disk 11 having a small inertial mass is accelerated or decelerated. .

In this way, which disk 11
Also in the above, the time required to control the rotation speed can be the same. It should be noted that with the optimum drive torque for accelerating or decelerating the disk 11 having a large inertial mass,
If the disk motor 12 is controlled so as to accelerate or decelerate the disk 11 having a small inertial mass, the disk motor 12 will generate an excessive drive torque, and the CLV servo after the track jump will not be performed stably. The problem arises. Therefore, in the state where the disk 11 having a small inertial mass is mounted, the drive torque generated in the disk motor 12 for accelerating or decelerating the disk motor 12 is changed to the state where the disk 11 having a large inertial mass is mounted. In comparison, it will be necessary to suppress it.

Further, regardless of whether the disk 11 having a large inertia mass or a small inertia mass is mounted, the drive for causing the disk motor 12 to be decelerated more than to accelerate the disk motor 12, respectively. It goes without saying that the torque is controlled so as to be suppressed.

Further, the disk 11 and the disk motor 1
2, the optical head 13 and the like are housed in a housing (not shown) of the disk drive system, for example, in a substantially sealed space capable of blocking dust, dust, gas, etc., and control the drive torque of the disk motor 12. If various circuit elements as shown in FIG. 2 are arranged outside the space, heat generated from the various circuit elements is not transferred to the optical head 13 and the like, and adverse effects due to the heat are not generated. Can be prevented. In particular, the transistor Q6 forming the current limiting circuit 24 can be easily arranged outside the housing because the number of wires can be reduced because the DC power supply voltage + B is supplied from outside the housing. The present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the scope of the invention.

[0054]

As described above in detail, according to the present invention,
By changing the drive torque generated by the disk motor between acceleration and deceleration, the time required for the relative speed between the disk and head to reach a constant value after the track jump to the inner and outer circumferences of the disk. It is possible to provide a very good disk motor control device capable of controlling the above.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of a disk motor control device according to the present invention.

FIG. 2 is a block circuit configuration diagram showing details of a main part of the embodiment.

FIG. 3 is a block circuit configuration diagram showing a modified example of the same embodiment.

FIG. 4 is a block diagram showing a conventional disk motor control means.

[Explanation of symbols]

11 ... Disk, 12 ... Disk motor, 13 ... Optical head, 14 ... Synchronous signal extraction circuit, 15 ... Frequency comparison circuit, 16 ... Reference signal generation circuit, 17 ... Power amplification circuit, 1
8 ... Signal processing circuit, 19 ... Output terminal, 20 ... Level detecting circuit, 21 ... Level comparing circuit, 22 ... Torque direction determining circuit, 23 ... Reference level generating circuit, 24 ... Current limiting circuit,
25, 26 ... Input terminal, 27 ... Changeover switch, 28-3
0 ... Input terminal, 31 ... Rotation speed control circuit, 32 ... Input terminal, 33 ... Output terminal.

Claims (8)

[Claims] 1. A disk, a disk motor for rotationally driving the disk, a head for recording or reproducing data on the disk rotationally driven by the disk motor, and a relative position between the head and the disk. Servo means for controlling the rotation speed of the disk motor so that the speed is constant, and track jump means for moving the head at high speed in the radial direction of the disk,
During and after the high speed movement of the head by the track jump means is completed, the servo speed of the disk motor is controlled by the servo means so that the relative speed between the head and the disk becomes constant. To
The drive torque generated in the disk motor is reduced when the rotation speed of the disk motor is controlled to be decelerated than when the rotation speed of the disk motor is controlled to be accelerated. A disk motor control device comprising control means for controlling the above. 2. The servo means outputs a sync signal extracting means for extracting a sync signal from an output signal of the head, a reference signal generating means for generating a reference signal of a constant frequency, and the reference signal generating means. Frequency comparison means for comparing the frequency of a reference signal and the synchronization signal extracted by the synchronization signal extraction means, and a drive signal for generating a drive signal for rotationally driving the disk motor based on the comparison result of the frequency comparison means. 2. The disk motor control device according to claim 1, further comprising a generation unit. 3. The disk motor when the rotation speed of the disk motor is controlled to be decelerated more than when the rotation speed of the disk motor is controlled to be accelerated. 3. The disk motor control device according to claim 1, wherein a drive torque generated in the disk motor is reduced by reducing a magnitude of a current supplied to the disk motor. 4. The discriminating means discriminates whether to accelerate or decelerate the rotation speed of the disk motor based on the comparison result of the frequency comparing means, and the control means mutually based on the discriminating result of the discriminating means. Different first and second
The reference level generating means for selectively generating the reference level, the voltage level generating means for generating the voltage level corresponding to the current flowing through the disk motor, the voltage level generated by the voltage level generating means and the reference level. It comprises level comparison means for level comparison with the first or second reference level generated from generation, and limiting means for controlling the drive signal generation means based on the comparison result of the level comparison means. The disk motor control device according to claim 2, wherein 5. The disk motor is a motor with a brush, and the control means includes a switching means for permitting or blocking the control of the drive signal generating means by the limiting means. Item 4. The disk motor control device according to item 4. 6. The servo means selectively generates first and second reference signals having frequencies different from each other from the reference signal generating means, so that the relative speed between the head and the disk is first. And a second relative speed that is faster than the first relative speed, the control means is configured to selectively set the first relative speed and the second relative speed. Compared with the case where the drive torque generated in the disk motor is controlled to be reduced when the disk is decelerated rather than the case where the disk is accelerated, as compared with the case where the disk is accelerated or decelerated at the first relative speed When the disk is accelerated or decelerated at the second relative speed, the drive torque generated in the disk motor is increased. The disk motor control device according to claim 2. 7. The disk motor is selectively mounted with a first disk and a second disk having a larger inertial mass than the first disk, and the control means accelerates the first disk. In comparison with the case of decelerating, the case of accelerating or decelerating the second disk is
2. The disc motor control device according to claim 1, wherein the drive torque generated in the disc motor is increased. 8. The disk, the disk motor and the head are housed in a substantially sealed space in a housing, and a circuit element for controlling a drive torque of the disk motor provided in the control means is provided in the space. The disk motor control device according to claim 1, wherein the disk motor control device is arranged outside.