JPH09330558A - Disk reproducing equipment and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an overall access speed without causing an excessive increase in the whole quantity of heat from a disk motor and a drive circuit thereof, by conducting an optimum variable control of a gain of a torque command for the disk motor. SOLUTION: In a case when an access demand waiting time is short, a gain is set at a rather low value and thereby the heat from a disk motor 36 and a drive circuit thereof is decreased, because the merit of making high the speed of control of the number of revolutions of the disk motor 36 is small in terms of an improvement of an overall access speed. In the case when the access demand waiting time is long, the gain is set at a rather high value and thereby a high torque is generated in the disk motor 36 to make the speed of a CLV control high. By this method, the overall access speed can be improved without causing an excessive increase in the quantity of the heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus such as a CD-ROM drive and a control method thereof.

[0002]

2. Description of the Related Art CD for controlling CLV of a disk motor
-In the operation of the ROM drive, a considerable amount of heat is generated from the disk motor and its drive circuit during its operation. Since the CD-ROM drive has a closed structure to prevent invasion of dust and the like from the outside, it is difficult for heat to escape to the outside, and the temperature inside the device easily rises.
In particular, in recent years, the speed of the CD-ROM drive has been increased to 4 times, 6 times, and 8 times, and the amount of heat generated by the disk motor and its drive circuit tends to increase more and more. Deterioration of the characteristics of various electronic components has been exposed as a real problem.

Therefore, in a CD-ROM drive for high-speed reproduction, the drive current supplied to the disk motor is controlled so that the above-mentioned heat generation can be suppressed to the extent that there is no problem in terms of the durability of various electronic parts in the apparatus. It is limited to a value much lower than the value.

However, if the drive current supplied to the disk motor is reduced, the torque generated in the disk motor is also reduced. Therefore, in the CLV control, it takes a long time until the rotational speed of the disk motor converges to the target rotational speed. Will end up. In particular, the length of the CLV control time becomes conspicuous when there is a large difference between the current rotation speed of the disk motor and the target rotation speed.

[0005]

As described above, in the conventional disc reproducing apparatus, the CLV control is performed by supplying a constant drive current with a constant gain of the torque command given to the disc motor. If the fixed value of the gain is set large, the problem of heat generation becomes serious, and if it is set small, the CLV control time increases due to insufficient torque.

The present invention is intended to solve such a problem. By optimally variably controlling the gain of the torque command to the disk motor, the overall heat generation from the disk motor and its drive circuit becomes excessive. It is an object of the present invention to provide a disc reproducing apparatus and a control method thereof that can improve the overall access speed without increasing the size.

[0007]

In order to achieve the above-mentioned object, a disk reproducing apparatus of the present invention has a disk motor for driving a disk as described in claim 1.
A torque command generating means for generating a torque command for the disk motor, a variable gain amplifying means for amplifying the torque command generated by the torque command generating means with a set gain and giving it to the disk motor, and a waiting time for an access request are measured. The time measuring means and the control means for controlling the gain variable amplifying means so as to set the optimum gain based on the waiting time of the access request measured by the time measuring means.

Then, the control means compares the waiting time of the access request measured by the time measuring means with the threshold value, and the waiting time of the access request is equal to or more than the threshold value. In the case of the variable gain amplifying means, the first
Is set, and if the wait time of the measured access request is less than the threshold value, the gain variable amplification means is set to the first
The gain is controlled so as to set the second gain smaller than the gain.

Therefore, according to the present invention, in a situation where the waiting time of the access request is short, a lower value is set as the gain value with respect to the torque command, and conversely, in a situation where the waiting time of the access request is long, By generating a high torque in the disk motor by setting a higher value as the gain value for the torque command, the overall heat generation from the disk motor and its drive circuit is not excessively increased, and the overall It is possible to improve various access speeds.

According to a third aspect of the present invention, there is provided a disc reproducing apparatus comprising: a disc motor for driving a disc; a torque command generating means for generating a torque command for the disc motor; and a torque command generating means. A variable gain amplifying means for amplifying the generated torque command with a set gain and giving it to the disk motor, a counting means for counting the number of access requests generated per predetermined time, and an access per predetermined time counted by the counting means. And a control means for controlling the gain variable amplification means so as to set an optimum gain based on the number of times the request is generated.

Then, the control means compares the number of occurrences of the access request per predetermined time counted by the counting means with the threshold value, and the generation of the access request per predetermined time as described in claim 4. If the number of times is less than the threshold value, the first gain is set in the variable gain amplifying means, and if the number of access requests generated per predetermined time is more than the threshold value, the gain variable amplifying means is smaller than the first gain. The control is performed so as to set the second gain.

Therefore, according to the present invention, the number of access requests generated per predetermined time is large, and even if the rotational speed control of the disk motor is speeded up, there is little merit in terms of improving the overall access speed. In
Set a low gain value for the torque command, and conversely, in a situation where the number of access requests generated per predetermined time is small, set a high gain value for the torque command and set a high value for the disk motor. By generating the torque, it is possible to improve the overall access speed without causing an excessive increase in the overall heat generation amount from the disk motor and its drive circuit.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a CD showing a first embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a ROM drive.

The optical pickup 1 allows the CD-RO
The signal read from the M disk 2 is the RF amplifier circuit 3
Is supplied to. The RF amplifier circuit 3 extracts the focus error signal and the tracking error signal 4 from the output of the optical pickup 1, and the focus / tracking control circuit 5
And the amplified RF signal 7 is supplied to the level slice / PLL circuit 6. The focus / tracking control circuit 5 generates a lens control signal of the optical pickup 1 from the focus error signal and the tracking error signal 4 supplied from the RF amplifier circuit 3 and supplies the lens control signal to the optical pickup 1.

The feed motor control circuit 8 receives a tracking error component supplied from the focus / tracking control circuit 5, a pulse signal 10 detected according to the rotation of the feed motor detected by the feed motor 9, and a system control circuit 11. A drive signal 13 for the feed motor 9 is generated from the supplied search instruction signal 12 and supplied.

The level slice / PLL circuit 6 binarizes the RF signal to obtain an EFM signal, and at the same time, generates a PLL clock 14 synchronized with the EFM signal in order to read the EFM signal. The binarized EFM signal 15 is supplied to the CD signal processing circuit 16. Further, the PLL clock 14 is supplied to the CD signal processing circuit 16 and the selector 17.

The CD signal processing circuit 16 uses the PLL clock 1
4 is used to detect the CD sync signal, and based on this, data separation and EFM demodulation are performed. And the CD signal processing circuit 16
Extracts only the subcode data 18 from the demodulated data and supplies it to the system control circuit 11, and writes other main data in the RAM 19 in accordance with the PLL clock 14. Further, the CD signal processing circuit 16 reads out data from the RAM 19 according to the clock supplied through the selector 17 and performs correction processing.
The detected CD frame synchronization signal 22 is supplied to the CLV motor control circuit 23. On the other hand, the corrected data is sent to the interpolation circuit 25 or C via the selector 24.
It is supplied to the D-ROM signal processing circuit 26.

The selector 17 is switched by an audio / ROM switching instruction signal 27 output from the system control circuit 11. The selector 17 selects the X'TAL clock 21a output from the clock generator 20 when audio is instructed by the instruction signal 27, and is output from the level slice / PLL circuit 6 when ROM is instructed. The reproduced PLL clock 14 is selected and supplied to the CD signal processing circuit 16.

Switching of the selector 24 is also performed by the audio / ROM switching instruction signal 27 output from the system control circuit 11. The selector 24 supplies data to the interpolation circuit 25 when audio is instructed by the instruction signal 27, and supplies data to the CD-ROM signal processing circuit 26 when ROM is instructed.
The interpolation circuit 25 interpolates the data only when the data has an error flag, and supplies the output to the DA converter 28. The DA converter 28 converts the data from digital to analog and outputs it as a reproduced audio signal through an LPF (low pass filter) 28a.

The CD-ROM signal processing circuit 26 is a CD-ROM.
CD-ROM sync signal detection from ROM data, CD
-Descramble ROM data, correct CD-ROM data, and control writing / reading of data to / from the Buffer memory 29. CD-ROM sync signal detection and CD-ROM data descramble
According to the clock supplied from the selector 17,
The data correction processing and the control of writing / reading data to / from the buffer memory 29 are performed according to the clock 21b supplied from the clock generator 20. Buffer
The data read from the memory 29 is transferred to the host computer, which is an external device, through the interface control circuit 30.

The interface control circuit 30 sends and receives operation commands and data with the host computer,
Performs communication control related to the interface. The operation command is transmitted and received between the system control circuit 11 and the host computer via the interface control circuit 30.

The system control circuit 11 searches,
The operation control of the entire CD-ROM, such as the operation ON / OFF control of each circuit, is performed. Further, the system control circuit 11 determines whether the main data is audio data or CD-ROM data from the subcode data demodulated by the CD signal processing circuit 16, and outputs an audio / ROM switching instruction signal 27 according to the result to each of the selectors 17. , 24. Further, the system control circuit 11 detects the waiting time of the access request (access interval) and the difference between the current rotation speed of the disk motor 36 and the target rotation speed (track jump level), and compares them with the respective threshold values. The gain control signal 33 is output to the CLV motor control circuit 23 so as to set the optimum value as the gain for the torque command based on the evaluation result of the comparison. The disk motor 36
Can be detected based on the frequency of the FG pulse 34 supplied from the FG pulse detector 32.

The CLV motor control circuit 23 is an audio / ROM supplied from the system control circuit 11.
A torque is generated in the disk motor 36 based on the switching instruction signal 27, the PLL frame synchronization signal 22 supplied from the CD signal processing circuit 16, and the X'TAL system clock 21c supplied from the clock generator 20. A torque command (drive current) 35 for generating the torque command is generated. The CLV motor control circuit 23 switches the gain of the torque command 35 given to the disk motor 36 based on the gain control signal 33 input from the system control circuit 11.

FIG. 2 shows the configuration of the gain switching unit for this torque command.

Here, the torque command 35 is a signal corresponding to an error between the current rotation speed of the disk motor 36 and the target rotation speed. This torque command 35 is amplified by a gain K1 by an amplifier 42 having a gain coefficient K1 (where K1> 1) when the switch unit 41 is closed, and a gain coefficient K2 (where K2> 1 when the switch unit 41 is open). ) Amplifier 43 and the amplifier 42 described above, K1 × K2 (K1 × K2> K1)
And is supplied as a drive current to the disk motor 36. The switch unit 41 is opened / closed by the gain control signal 33 from the system control circuit 11.

Next, the operation of the gain switching control of the torque command will be described with reference to the flowcharts of FIGS. 3 and 4.

At the same time when the system is started up, the system control circuit 11 first initializes an internal timer (step 301), opens the switch section 41 by the gain control signal 33, and sets the gain for the torque command to K1 × K2. (Step 302). After that, the system control circuit 11 turns on the timer (step 303), and subsequently turns on the focus servo, the forced acceleration and the CLV servo, and the tracking servo in order (steps 304, 305, 306), and then the pause state, that is, the host computer. (Step 307).

After that, when the system control circuit 11 receives an access request (step 308), it compares the current timer value T with the threshold value Tth (step 309 in FIG. 4), and T≤Tth (access request waiting time). Is shorter than the threshold value), the track jump level JL, that is, the difference between the current rotational speed of the disk motor and the target rotational speed corresponding to the target track position, and a preset threshold value J
Lth is compared (step 310). If JL <JLth, the switch section 41 is controlled by the gain control signal 33.
Open and set the gain for the torque command to K1 × K2
To K1 (step 311) After that, access processing is executed (step 312),
After the access processing is completed, the timer is reset (step 313), and if the gain is changed to K1, this is returned to the initial value (K1 × K2) (step 314,
315), the state of waiting for the next access request is entered (step 307).

Further, when the value T of the timer is compared with the threshold value Tth in step 309 and T> Tth (the access request waiting time is longer than the threshold value), or T ≦ Tth.
Even in the case of, JL ≧ JL by comparing the track jump level JL and the threshold value JLth in step 310
In the case of th, the access processing is executed as it is without changing the gain as the initial value (K1 × K2).

When the stop command is received (step 316), the system control circuit 11 turns off the tracking servo (step 317), and then turns off the forced deceleration of the disk motor and the CLV control (step 318). The forced deceleration of the disk motor is performed by giving a torque command, which has a positive and negative polarity opposite to that at the time of acceleration, to the disk motor as a brake signal. Since the gain at this time is set to a high value (K1 × K2), the strong braking force acts on the disk motor,
The disk motor quickly goes to a standstill. After the disk motor is stopped (step 319), the focus servo is turned off (step 320), and the whole operation is completed.

That is, in the present embodiment, when the access request waiting time is less than the threshold value and the track jump level is less than the threshold value, even if the rotation speed control of the disk motor is speeded up, the overall Since there is little merit in terms of improving the access speed, in such a case, it is prioritized to set the gain to a low value (K1) to reduce heat generation from the disk motor and its drive circuit. If the request waiting time is larger than the threshold value, or if the track jump level is above the threshold value even if the access request waiting time is below the threshold value, set the gain to a higher value (K1 × K2). Then, the CLV control is speeded up by generating a high torque in the disk motor.

Thus, according to this embodiment, the overall access speed can be improved without causing an excessive increase in the overall heat generation amount from the disk motor and its drive circuit.

Next, a second embodiment of the present invention will be described. FIG. 5 is a flowchart showing a characteristic part of the operation of the torque command gain switching control of the present embodiment.

The feature of this embodiment is that when an access request is received, the current value T of the timer is compared with the threshold value Tth (step 509), and if T ≦ Tth (the access request waiting time is less than or equal to the threshold value). In this case, the gain for the torque command is reduced from K1 × K2 to K1 (step 510). That is, this method controls the gain of the torque command based on the access request waiting time (regardless of the track jump level), and other operations are the same as those in the above-described embodiment.

With this method as well, it is possible to improve the overall access speed without causing an excessive increase in the overall amount of heat generated from the disk motor and its drive circuit. In this method, when the access request waiting time is short, the gain with respect to the torque command is reduced from K1 × K2 to K1 even if the track jump level is large. Therefore, the degree to which the access speed can be improved does not reach that of the first embodiment. The overall heat generation amount can be reduced as compared with the first embodiment.

In the above embodiment, the length of the access request waiting time is used as one of the factors for determining the gain with respect to the torque command. However, the number of access requests generated per unit time is counted, and this unit time is counted. It is configured to determine the gain for the torque command by using the result of comparison between the number of access requests generated per hit and the threshold value as one of the factors for determining the gain for the torque command (or by using only the comparison result). May be.

Further, in the above embodiment, the gain for the torque command is switched only in two steps, large and small, but the threshold value Tth for access duty and the threshold value JLth for track jump level are set in multiple stages. By doing so, the gain may be switched in more stages. For example, the gain may be variable in an analog manner.

[0039]

As described above, according to the disk reproducing apparatus and the control method thereof of the present invention, the waiting time for an access request is short, and the overall access speed is improved even if the speed control of the disk motor is accelerated. From the aspect of the above, when the merit is small, a low value is set as the gain value for the torque command, and conversely, when the waiting time of the access request is long, the gain value for the torque command is higher. By generating a high torque in the disk motor by setting the above, it is possible to improve the overall access speed without causing an excessive increase in the overall heat generation amount from the disk motor and its drive circuit. .

Further, according to the present invention, the number of access requests generated per predetermined time is large, and even if the rotational speed control of the disk motor is speeded up, there is little merit in terms of improving the overall access speed. In, set a lower value as the gain value for the torque command,
On the other hand, in a situation where the number of access requests generated per predetermined time is small, a high value is set as the gain value for the torque command to generate high torque in the disk motor, so that the disk motor and its drive circuit can generate high torque. It is possible to improve the overall access speed without causing an excessive increase in the overall heat generation amount.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a CD-ROM drive according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of a torque command gain switching unit in the CLV motor control circuit of FIG.

FIG. 3 is a flowchart showing a procedure of torque command gain switching control in the first embodiment.

FIG. 4 is a flowchart showing a procedure of torque command gain switching control according to the first embodiment.

FIG. 5 is a flowchart showing a procedure of torque command gain switching control according to the second embodiment.

[Explanation of symbols]

 2 ………… CD-ROM disc 11 …… System control circuit 23 …… CLV motor control circuit 33 …… Gain control signal 35 …… Torque command 36 …… Disk motor 41 …… Switch section 42 …… K1 amplifier 43 …… K2 amplifier

Claims (8)

[Claims] 1. A disk motor for driving a disk, a torque command generating means for generating a torque command for the disk motor, and a disk motor for amplifying a torque command generated by the torque command generating means with a set gain. To the variable gain amplifying means, the time measuring means for measuring the waiting time of the access request, and the optimum gain for the variable gain amplifying means based on the waiting time of the access request measured by the time measuring means. A disc reproducing apparatus, comprising: 2. The disc reproducing apparatus according to claim 1, wherein the control unit compares the waiting time of the access request measured by the time measuring unit with a threshold value, and the waiting time of the access request is threshold. If the value is equal to or more than the value, a first gain is set in the variable gain amplifying means, and if the wait time of the measured access request is less than a threshold value, the variable gain amplifying means is set to a first gain smaller than the first gain. A disc reproducing apparatus characterized by controlling so as to set a gain of 2. 3. A disk motor for driving a disk, a torque command generating means for generating a torque command for the disk motor, and a disk motor for amplifying a torque command generated by the torque command generating means with a set gain. To the variable gain amplifying means based on the number of access request generations per predetermined time counted by the counting means; A disc reproducing apparatus comprising: a control unit that controls so as to set an optimum gain. 4. The disk reproducing apparatus according to claim 3, wherein the control unit compares the number of times of access requests generated per predetermined time counted by the counting unit with a threshold value, and accesses per predetermined time. If the number of requests generated is less than the threshold value, the first gain is set in the gain variable amplification means, and if the number of access requests generated per predetermined time is equal to or greater than the threshold value, the gain variable amplification means is set A disc reproducing apparatus, wherein control is performed so as to set a second gain smaller than the first gain. 5. An access request wait time is measured, an optimum value is set as a gain of a torque command for a disk motor based on the measured access request wait time, and the torque command is amplified by the set gain. Then, a method for controlling a disk reproducing device is provided to the disk motor. 6. The waiting time of the access request is measured, the waiting time of the measured access request is compared with a threshold value, and when the measured waiting time of the access request is equal to or more than the threshold value, a torque command for the disk motor is sent. 1st as gain
Is set, and if the measured waiting time of the access request is less than the threshold value, a second value smaller than the first value is set as the gain of the torque command, and the torque is set at the set gain. A method for controlling a disc reproducing apparatus, characterized in that a command is amplified and given to the disc motor. 7. The number of access requests generated per predetermined time is counted, and based on the counted number of access requests generated per predetermined time, an optimum value is set and set as a gain of a torque command for a disk motor. A method for controlling a disc reproducing apparatus, characterized in that the torque command is amplified by the gain and given to the disc motor. 8. The number of access requests generated per predetermined time is counted, the counted number of access requests per predetermined time is compared with a threshold, and the counted number of access requests per predetermined time is calculated. If it is less than the threshold value, a first value is set as the gain of the torque command to the disk motor, and if the number of times of the access request generated per the predetermined time is equal to or more than a threshold value, the gain of the torque command is set as the A method for controlling a disc reproducing apparatus, wherein a second value smaller than the value of 1 is set, and the torque command is amplified by the set gain and given to the disc motor.