JPH08185663A - Disk device - Google Patents

Abstract

PURPOSE: To shorten an access time and to reduce the power consumption by controlling the rotational speed of a spindle motor so that the rotational speed of a disk shaped storage medium become higher as compared with a speculated standard rotational speed. CONSTITUTION: Frequency-dividing ratios M and N of frequency-dividing circuits 42, 43 are set so as to correspond to laser beam irradiating positions by a system control circuit 41 and the rotational speed is changed by frequency- dividing ratios M and N recorded in a frequency-dividing ratio table 46 so as to correspond to the laser beam irradiating positions. Consequently, the rotational speed of a CD-ROM 2 is successively changed from a quadruple speed to a sextuple speed toward from an innermost peripheral to an outermost peripheral. Thus, since the variable range of the rotational speed is reduced as compared with that in the case of a CLV method and a time required for changing over the rotational speed is shortened by the amount, a seek time is shortened and also the power consumption is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive,
It is applied to CD-ROM (Compact disc Read Only Memory) drives, etc., and used in CLV (Constant Linear Velocit).
The present invention relates to rotation control of a spindle motor when rotating a disk-shaped recording medium based on the y) method.

[0002]

2. Description of the Related Art Conventionally, a CD-ROM is formed so that the linear recording density is constant in the inner and outer rims, whereby the CAV is formed.
It is designed to improve the recording density compared to the (Constant Angular Velocity) type optical disc. For this reason, in the CD-ROM drive, C
By controlling the rotation speed of the D-ROM, it is possible to reliably reproduce the data recorded under the condition that the linear recording density is constant.

That is, as shown in FIG. 7, a CD-ROM
The drive 1 is a CD-ROM driven by the spindle motor 3.
2 is driven to rotate, and in this state, the optical pickup 4
The D-ROM 2 is irradiated with a laser beam. Here, the optical pickup 4 is held so as to be movable in the radial direction of the CD-ROM 2, whereby the CD-ROM drive 1
Then, the optical pickup 4 is moved to access desired data.

Further, the optical pickup 4 emits a laser beam from a built-in laser diode 5 and the laser beam is converted into parallel rays by a relay lens 6. Further, the optical pickup 4 transmits the parallel light rays through the beam splitter 7 and guides them to the objective lens 8, which converts them into convergent light. As a result, the optical pickup 4 outputs the laser beam from the laser diode 5 to C
The light is focused on the information recording surface of the D-ROM 2.

Further, the optical pickup 4 receives the returned light of this laser beam by an objective lens 8, converts it into parallel rays and guides it to a beam splitter 7. Here, the optical pickup 4 reflects the return light by the beam splitter 7 and guides it to the relay lens 9, which condenses it on the light receiving surface of the photodetector 10.

The photodetector 10 is formed by dividing the light-receiving surface, converts the output current of each light-receiving surface into a current-voltage value, amplifies it with a predetermined gain, and outputs it to a matrix circuit (not shown). Here, this matrix circuit generates a focus error signal, a tracking error signal, and a reproduction signal RF from these output signals, and in the CD-ROM drive 1, the objective lens 8 is moved up and down based on the focus error signal and the tracking error signal, respectively. It is movable to the left and right to perform tracking control and focus control.

On the other hand, the reproduction signal RF is generated so that the signal level changes in accordance with the change in the amount of return light, and the EFM (Eight to Fourteen Modulation) signal detection circuit 12 defines the reproduction signal RF. After the amplification with the amplification factor of 1, the asymmetry is corrected. Further, the EFM signal detection circuit 12 binarizes the reproduction signal RF after performing processing such as a defect, thereby generating an EFM signal EFM composed of serial data.

The clock detection circuit 13 includes a PLL (Phase
Locked Loop) circuit, and detects the reproduction clock CK based on the edge of this EFM signal. The digital signal processing circuit 14 decodes the EFM signal EFM with reference to the reproduction clock CK, and further executes error correction processing and the like. Therefore, in the CD-ROM drive 1,
In response to commands from a computer connected to the outside,
The output data D1 of the digital signal processing circuit 14 is output in a specified format.

The reference clock circuit 15 generates a reference clock whose logic level is switched at a prescribed number of cycles, and the frequency dividing circuits 16 and 17 respectively reproduce the reproduction clock CK and the reference clock at prescribed frequency division ratios M and N. Divide. The phase comparison circuit 19 compares the output signals of the frequency dividing circuits 16 and 17 with each other, and outputs the phase comparison result to the driver 21 via the low pass filter (LPF) 20. The driver 21 controls the rotation speed of the spindle motor 3 so that the phase comparison result becomes 0 level.

As a result, in the CD-ROM drive 1, a servo loop is formed including a part of the reproducing system, and the division ratio M
The spindle motor 3 is arranged so that the reproduction clock CK divided by is synchronized in phase with the reference clock divided by the division ratio N.
Control the rotation speed of. As a result, as shown in FIG.
In the CD-ROM drive 1, with respect to the CD-ROM 2 recorded according to the condition that the linear recording density is constant, the CD-ROM is set so that the reproduction clock CK is maintained at the specified frequency.
2 is controlled so that the data recorded in the CD-ROM 2 is surely reproduced.

Correspondingly, in the CD-ROM 2, the linear velocity at the laser beam irradiation position is maintained at a constant value.
As shown in (4), the rotation speed is controlled so that the rotation speed is lower on the outer peripheral side than on the inner peripheral side.

[0012]

By the way, this kind of CD
The ROM drive 1 is required to increase the data transfer rate and shorten the time required for access by being used by being connected to a computer or the like.
Among them, the data transfer speed is increased by the CD-ROM2.
It is designed to be realized by increasing the rotation speed of.

That is, in the CD-ROM drive 1, the spindle servo system including the reproducing system forms a kind of PLL circuit, so that the frequency dividing ratio M of the frequency dividing circuits 16 and 17 is M.
And N can be selected to drive the CD-ROM 2 to rotate at a linear velocity higher than the standard linear velocity specified for the CD-ROM 2 (ie, the linear velocity of a compact disc).

For example, in this CD-ROM drive 1, the ratio of the frequency division ratios M and N is set to 1: 1 and the CD-RO is set.
When M2 rotates at the standard linear velocity, if the ratio of the frequency division ratios M and N is set to 2: 1, the operation of the spindle servo system can be switched so that the frequency of the reproduction clock CK is doubled. it can.

In this case, in the CD-ROM 2, CL
The rotation speed is controlled by the V method, and the rotation speed is further controlled so that the linear speed becomes twice the standard linear speed.
In the signal EFM, the data transfer rate is kept at twice the standard rate.

As a result, the conventional CD-ROM drive 1
Then, by selecting the frequency division ratios M and N of the frequency dividing circuits 16 and 17 in this way to increase the rotation speed of the spindle motor 3 and also improve the operation speed of the signal processing system, the CLV method is used. The CD-ROM 2 is rotationally driven to further improve the data transfer rate of the output data D1 (hereinafter, the operation of rotationally driving the CD-ROM 2 at a linear velocity higher than the standard linear velocity to reproduce the data is performed. Called double speed playback).

On the other hand, the time required for access is limited by the seek time, and the time required for this seek is limited by the time required for moving the optical pickup 4 and the time for switching the rotation speed of the spindle motor 3. It Among them, in the double speed reproduction, the seek time is limited by the time for moving the optical pickup 4. On the other hand, when the rotation speed of the CD-ROM 2 is further increased, the seek time is limited by the time for switching the rotation speed of the spindle motor 3.

This is because in the double speed reproduction, the spindle motor 3 is rotating at a high speed several times higher than that of the standard case. Therefore, when the rotation speed of the spindle motor 3 is switched, the time until settling is standard. Because it will be longer.

The spindle motor 3 for double speed reproduction
Since the spindle motor 3 is rotating at a high speed, a large torque is required to switch the rotation speed in comparison with the standard case, and the CD-ROM drive consumes a considerable amount of electric power.

Therefore, for example, in a portable computer or the like, C
If the D-ROM drive is built in, the internal temperature of the device may rise significantly, and the operation of the device may become unstable.
As a result, in the conventional CD-ROM drive 1,
There is a problem that it is difficult to shorten the access time and the power consumption is greatly increased in the double speed reproduction of 4 times or more speed.

As one method for solving this problem, C
CD-R formed by LV system to be rotationally driven
A method of rotationally driving the OM2 by the CAV method can be considered.

That is, in FIG. 10, reference numeral 30 denotes a CD-ROM drive to which the CAV system is applied as a whole,
This CD-ROM drive 30 includes a spindle motor 3
1 drives the CD-ROM 2 to rotate, and holds the rotation speed of the spindle motor 31 at a constant value. In FIG. 10, configurations common to those in FIG. 7 described above are denoted by corresponding reference numerals, and duplicated description will be omitted.

Here, the spindle motor 31 has a built-in rotation speed sensor, and this rotation speed sensor outputs a rotation speed detection signal S1 whose signal level rises according to the rotation speed. The spindle clock detection circuit 32 waveform-shapes the rotation speed detection signal S1 to obtain a CD-R.
A spindle clock whose logic level rises according to the rotation speed of OM2 is generated.

The reference clock circuit 33 generates a reference clock whose logic level is switched at a prescribed frequency, and the frequency dividing circuits 34 and 35 frequency-divide and output the spindle clock and the reference clock, respectively. With this, CD-RO
In the M drive 30, the phase comparison circuit 19 compares the phases of the output signals of the frequency dividing circuits 16 and 17, and the phase comparison result is passed through the low pass filter 20 to the driver 2
The spindle motor 31 controls the rotational speed of the spindle motor 31 so that the spindle clock output to 1 and divided by the division ratio M is in phase synchronization with the reference clock divided by the division ratio N. As a result, the CD-ROM 2 is rotationally driven at a constant angular velocity (FIG. 9).

As a result, the CD-ROM drive 30 is
Switching of the rotation speed of the spindle motor 31 can be omitted, and the time required for the seek is the optical pickup 4
Will be limited only by the time it takes to move. Therefore, according to this method, it is considered that the increase in power consumption can be effectively avoided and the access time can be shortened.

However, when the CD-ROM 2 based on the CLV system is rotationally driven by the CAV system as described above, the frequency of the reproduction signal RF becomes higher as the outer peripheral side is reproduced, and accordingly, the clock detection circuit 13 is produced.
The frequency of the reproduction clock CK (FIG. 8) detected at 1 also increases on the outer peripheral side. That is, diameter 12 [cm]
In the CD-ROM 2, the frequency of the reproduction clock CK is 2.5 times higher when the outermost circumference is reproduced than when the innermost circumference is reproduced.

Therefore, when controlling the rotation of the CD-ROM 2 by the CAV method in this way, there is a problem that it is difficult to reproduce at a speed of 4 times or more at present. That is, this CA
When the inner peripheral side of the CD-ROM 2 is set to the linear velocity of 4 times by the V method, the linear velocity of 10 times is held on the outer peripheral side of the CD-ROM 2, and the frequency of the reproduction clock CK is the standard. It is 10 times higher than the case.

On the other hand, in the integrated circuit forming the reproducing system of the CD-ROM drive 1, the reproducing clock CK is used.
When the frequency of is increased to 10 times the standard, it becomes difficult to operate correctly. Therefore, the CAV method is used for CD
-When the ROM 2 is reproduced at 4 times speed, the recorded data can be surely reproduced by operating the integrated circuit of the reproducing system at the maximum operable frequency or less on the inner peripheral side as shown in FIG. On the outer peripheral side, the frequency of the reproduction clock CK exceeds the maximum operable frequency, and the recorded data cannot be reproduced correctly.

The present invention has been made in consideration of the above points, and shortens the access time and effectively avoids an increase in power consumption when driving a disk-shaped recording medium based on the CLV system at double speed. The present invention intends to propose a disk device that can be used.

[0030]

In order to solve such a problem, in the present invention, data is recorded on a disc-shaped recording medium according to a condition of constant linear recording density, or data recorded according to a condition of constant linear recording density is recorded. A disc device for reproducing from a disc-shaped recording medium comprises a spindle motor for rotationally driving the disc-shaped recording medium, and spindle motor control means for controlling the rotational speed of the spindle motor according to the recording position or the reproducing position. The spindle motor control means controls the rotation speed of the disc-shaped recording medium to be higher than the standard rotation speed defined for the disc-shaped recording medium, and when recording or reproducing the innermost circumference. Rotational speed of the disk-shaped recording medium when recording or reproducing the outermost circumference, as compared to the rotational speed of the disk-shaped recording medium Reduced, compared to the linear velocity of the recording position or reproducing position when the further recording or reproducing innermost,
The rotation speed of the spindle motor is controlled so that the linear velocity at the recording position or the reproducing position when recording or reproducing the outermost circumference increases.

At this time, the above spindle motor control means converts the previous data into a recording signal, or processes the reproduction signal into a previous signal, and does not exceed the operable frequency of the signal processing system. In order to increase the linear velocity of the recording position or the reproducing position when recording or reproducing the outermost circumference, compared with the linear velocity of the recording position or the reproducing position when recording or reproducing the innermost periphery. Control the rotation speed of.

The above spindle motor control means is
The rotation speed of the spindle motor is controlled so that the rotation speed gradually or gradually decreases from the recording position or reproducing position on the innermost circumference to the recording position or reproducing position on the outermost circumference.

Alternatively, the above spindle motor control means keeps the rotational speed at a constant value within a prescribed range from the innermost recording position or reproducing position to the outermost recording position or reproducing position. After that, the rotation speed of the spindle motor is controlled so that the linear velocity at the recording position or the reproducing position becomes a constant value.

[0034]

In this spindle motor control means, if the rotation speed of the spindle motor is controlled so that the rotation speed of the disk-shaped recording medium is higher than the standard rotation speed specified for the disk-shaped recording medium, the standard It is possible to increase the data transfer rate as compared with the above case.
In addition to this, if the rotation speed of the spindle motor is controlled so that the rotation speed of the disk-shaped recording medium at the time of recording or reproducing at the outermost circumference is lower than that at the innermost circumference, the data transfer speed can be increased. In the speed-up state, the operation speed of the signal processing circuit of the recording / reproducing system can be reduced as compared with the case of the CAV method. Furthermore, if the rotation speed of the spindle motor is controlled so that the linear velocity at the recording position or the reproducing position at the time of recording or reproducing at the outermost circumference increases as compared to the innermost circumference, it will be compared to the case of the CLV method. Therefore, the variable range of the rotation speed can be reduced.

Thus, in the spindle motor control means, the spindle motor is controlled so that the linear velocity at the recording position or the reproducing position when recording or reproducing the outermost circumference is increased within a range not exceeding the operable frequency of the signal processing system. The data can be surely reproduced by controlling the rotation speed of the.

Particularly, in the spindle motor control means, the spindle motor is controlled so that the rotation speed changes from the innermost recording position or the reproducing position to the outermost recording position or the reproducing position in a sequential or stepwise manner. By controlling the rotation speed, it is possible to change the reproduction speed at the inner and outer circumferences at a constant rate.

Alternatively, in the spindle motor control means, after the rotation speed is maintained at a constant value in a prescribed range from the innermost recording position or reproducing position to the outermost recording position or reproducing position, Then, if the rotation speed of the spindle motor is controlled so that the linear velocity at the recording position or the reproduction position becomes a constant value, data with high access frequency is recorded in the area on the inner circumference side that holds this rotation speed at a constant value. Then, the time required to access the frequently accessed data can be shortened, and the access time can be shortened as a whole.

[0038]

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

In FIG. 1, 40 is a CD-R as a whole.
The system control circuit 41 sets the frequency division ratios M and N of the frequency division circuits 42 and 43 to set the rotation speed of the spindle motor 3. Note that, in FIG. 1, configurations common to the above-described conventional example are denoted by corresponding reference numerals, and duplicate description is omitted.

That is, this CD-ROM drive 40
Has a guide rod arranged so as to extend in the radial direction of the CD-ROM 2, and drives a linear actuator at the time of seeking to move the optical pickup 4 along the guide rod.
To move. Further, in this CD-ROM drive 40, a light spot position detection sensor composed of a position detection sensor is arranged along this guide rod. In response to this, the optical pickup 4 holds a light emitting diode, and the light from this light emitting diode is made to enter the light receiving surface of the position detection sensor.

As a result, the CD-ROM drive 40 can detect the position of the optical pickup 4 based on the detection result of the position detection sensor and roughly detect the laser beam irradiation position. Position detecting means 4
Reference numeral 4 denotes an analog-digital conversion circuit, these position detection sensors, and a light emitting diode of the optical pickup 4,
The detection result of the position detection sensor is converted into position detection information P1 by analog-digital conversion processing, and this position detection information P1 is output to the system control circuit 41. This gives C
In the D-ROM drive 40, the system control circuit 41 can roughly detect the laser beam irradiation position from the position detection information P1.

Further, in this embodiment, the digital signal processing circuit 45 decodes the EFM signal EFM to output the output data D1, detects the header added to the output data D1, and detects the header from the system control circuit. Output to 41. Here, in this type of CD-ROM 2, the address information indicating the physical position of the data is assigned to a predetermined area of the header, and the digital signal processing circuit 4
5 outputs the detected header to the system control circuit 41, thereby outputting the address information P2 to the system control circuit 41 together with other information.

As a result, the system control circuit 41 can detect the reproduction position with high accuracy based on the address information P2 obtained from this header.

The system control circuit 41 accesses the frequency division ratio table 46 on the basis of the reproduction position thus detected, and the frequency division circuit 42 and the frequency division circuit 42 according to the frequency division ratio recorded in the frequency division ratio table 46. The division ratios M and N of 43 are set. Therefore, the frequency dividing circuits 42 and 43 are each formed of a programmable counter, and frequency-divide the reproduction clock CK and the reference clock with the frequency division ratio set by the system control circuit 41.

On the other hand, as shown in FIG.
In the OM drive 40, the information recording surface of the CD-ROM 2 is concentrically divided into 200 virtual areas, and the frequency division ratio table 46 stores the reproduction positions of the respective virtual areas and the frequency division ratios M and M corresponding to the reproduction positions. N is recorded and formed in the read-only memory. In FIG. 2, r (0) and r (M
AX) indicates the innermost and outermost reproduction positions of the CD-ROM 2 by radius.

Further, the frequency division ratios M and N recorded in the frequency division ratio table 46 are, as shown in FIG.
When the frequency division ratios M and N of Nos. 17 and 17 are sequentially set to the values specified by the frequency division ratio table 46 and the corresponding reproduction position is reproduced in this state, the reproduction clock CK changes from the inner circumference side to the outer circumference side. The playback clock CK is set to 4 when the innermost circumference is played back.
It is selected to have a frequency corresponding to double speed double speed reproduction.

On the other hand, in the outermost circumference, the division ratios M and N are selected so that the reproduction clock CK has a frequency corresponding to 6 × speed reproduction. In this embodiment, the 6 × clock frequency is used. Is a digital signal processing circuit 45
With respect to the operable frequency of the integrated circuit, etc., it corresponds to the upper limit reproduction speed in consideration of variations in operating conditions.

That is, in the CD-ROM 2, if the linear velocity of the innermost circumference r (0) is v (0) and the linear velocity of radius r (x) is v (x), this radius and linear velocity In between

[Equation 1] The linear relation expressed by is established. CD-RO
In M2, the innermost and outermost radii are 25 [m each
m] and 58 [mm], when the innermost circumference is held at a quadruple speed linear velocity, the linear speed is maintained at 9.28 times at the outermost rim by substituting it into the equation (1). It will be.

As a result, in the CD-ROM drive 40, the ratio of the frequency division ratios M and N of the frequency division circuits 42 and 43 is 1 :.
If the CD-ROM 2 can be rotationally driven at the standard linear velocity when it is set to 1, the ratio of the frequency dividing ratios M and N is set to 4: 1 and the CD-R is driven at the quadruple speed by the CLV method.
The OM2 can be driven to rotate. Further CD-RO
In the M drive 40, the ratio of the frequency division ratios M and N is increased toward the outer circumference in proportion to the radius, and is increased to 9.2 at the outermost circumference.
If it is set to 8: 1, the CD-RO is produced by the CAV method at a rotation speed that can obtain a linear velocity of 4 times the innermost circumference.
The M2 can be rotationally driven.

Based on this relational expression, the innermost circumference r (0)
Linear velocity v (0) and outermost peripheral velocity r (MAX) linear velocity v
Linear velocity v at radius r (x) with respect to (MAX)
(X) is given by

[Equation 2] If the value represented by the relational expression is selected, the rotation speed of the CD-ROM 2 can be set so that the frequency of the reproduction clock CK changes substantially linearly as described above with reference to FIG.

By modifying the relational expression of the equation (2), the following equation is obtained.

(Equation 3) Can be obtained. According to the expression (3), the frequency division ratio table 46 indicates that the linear velocity v (0) of the innermost circumference r (0) and the linear velocity v (MAX) of the outermost circumference r (MAX) are 4 times speed and 6 speed, respectively. The division ratios M and N are recorded so that the speed becomes double, and the linear velocities v (MAX) and v
The division ratios M and N of the radius r (x) are sequentially recorded and formed with respect to (0).

By the way, in this case,

[Equation 4] When the linear velocity v (50) with a radius of 50 [mm] is obtained, the value 0.0606 can be substituted into the equation (3) to obtain the value 5.515. It will be understood that the linear velocity corresponding to 5.515 times speed may be set at the position of the radius of 50 [mm]. This is the CD
In the ROM drive 40, when reproducing the position of the radius 50 [mm], the ratio of the frequency division ratios M and N is 5.515:
It can be seen that it should be set to 1.

Based on these relationships, in the frequency division ratio table 46, the frequency division ratios M and N are set to the values 400 and 100 at the innermost circumference and to the values 600 and 100 at the outermost circumference. In the meantime, the division ratios M and N are set so as to satisfy the relational expression (3).
By the way, the frequency division ratios M and N of the radius 50 [mm] described above are
It will be set to the values 552 and 100 respectively.

To the frequency division ratio table 46, the system control circuit 41 accesses the frequency division ratio table 46 based on the position detection information P1 at the time of seek, and the frequency division ratios M and M of the frequency division circuits 42 and 43 are accessed. N is set to the frequency division ratios M and N recorded in the frequency division ratio table 46. Further, the system control circuit 41 is required when the spindle motor 3 is settled at the set frequency division ratios M and N after a predetermined time elapses and the address information P2 of the laser beam irradiation position is detected from the digital signal processing circuit 45. The optical pickup 4 is moved in accordance with the above, and the laser beam irradiation position is corrected to the target irradiation position.

Further, in the system control circuit 41, after the optical pickup 4 is moved to the target laser beam irradiation position, the laser beam is on-track and the digital signal processing circuit 45 detects the address information P2 of the laser beam irradiation position. Then, the digital signal processing circuit 4 is used instead of the position detection information P1 detected by the position detection means 44.
The frequency division ratio table 46 is accessed using the address information P2 obtained from No. 5, and the frequency division ratio M of the frequency division circuits 42 and 43 is accessed.
And N are frequency division ratios M recorded in the frequency division ratio table 46.
And N. This allows the CD-ROM drive 4
At 0, the precision of the spindle servo is increased as required.

Further, after the seek, the system control circuit 41 continuously C-crosses a plurality of virtual areas.
When reproducing the D-ROM 2, the frequency division ratios M and N of the frequency division circuits 42 and 43 are sequentially used at the frequency division ratios M and N recorded in the frequency division ratio table 46 in accordance with the change of the address information P2. Update.

As a result, the symbol L1 in FIGS.
As shown in, in the CD-ROM drive 40,
Within the range that does not exceed the operable frequency of the playback system, CD-RO
The frequency of the reproduction clock CK in the radial direction of M2 is
It exhibits an intermediate change between the case where the CD-ROM 2 is rotationally driven by the CLV system (represented by CLV in FIG. 3) and the case where the CD-ROM 2 is rotationally driven by the CAV system (represented by CAV in FIG. 3). On the CD
Change the rotation speed of ROM2.

Therefore, in the CD-ROM drive 40, C
It is possible to reduce the variable range of the rotation speed of the spindle motor 3 as compared with the case of performing the double speed reproduction by the LV method, and it is possible to effectively avoid the increase in power consumption by that amount. Also, the time required for switching can be shortened, and the time required for seek can be shortened as compared with the case of reproducing at 4 × speed by the CLV method.

As for the reproduction clock CK, CA
It is possible to effectively avoid a large increase in frequency, such as in the case of double-speed reproduction by the V method, which allows the CD-
The data recorded in the ROM 2 can be reliably reproduced.

Further, the frequency division ratio table 46 is accessed to detect the frequency division ratio to be set, so that the frequency division ratio can be set more simply and easily than in the case where the arithmetic processing of the equation (3) is executed to set the frequency division ratio. The frequency division ratio can be set with certainty.

In the above structure, the CD-ROM 2 is
While being driven to rotate by the spindle motor 3, a laser beam is focused on the information recording surface, and the return light of the laser beam is received by the optical pickup 4, which causes a signal to follow the change in the light amount of the return light. The reproduction signal RF whose level changes is detected.

The reproduction signal RF is converted into an EFM signal EFM in the EFM signal detection circuit 12, and the reproduction clock CK is detected from the EFM signal EFM in the clock detection circuit 13. As a result, the EFM signal EFM is decoded in the digital signal processing circuit 45 based on the reproduction clock CK, and the data D1 recorded in the CD-ROM 2 is decoded.

After being generated in this way, the reproduction clock CK used for data decoding is frequency-divided by the frequency division circuit 42 by the frequency division ratio M set by the system control circuit 41, and then the reference clock CK. Is compared with the output signal of the frequency dividing circuit 43 obtained by dividing the frequency by the frequency dividing ratio N in the phase comparing circuit 19, and the rotation speed of the spindle motor 3 is controlled so that the phase comparison result becomes 0 level. This gives C
The D-ROM 2 is a reproduction clock CK divided by the division ratio M.
Is rotated and driven by the spindle motor 3 so as to be phase-synchronized with the reference clock divided by the division ratio N, and is set to a prescribed rotation speed.

The system control circuit 41 accesses the frequency division ratio table 46 to determine the rotation speed.
By setting the frequency division ratios M and N of 3, the rotation speed determined by the frequency division ratio recorded in the frequency division ratio table 46 is set.

Further, in the state of being rotationally driven in this way, in the CD-ROM 2, the position of the optical pickup 4 is detected by the light spot position detection sensor, and the detection result is output to the system control circuit 41 by the position detection means 44. Is
As a result, the system control circuit 41 roughly detects the irradiation position of the laser beam at the reproduction position.

Further, in the CD-ROM 2, when the recorded data is properly reproduced by the reproducing system, the reproduced header information is output from the digital signal processing circuit 45 to the system control circuit 41, whereby the system control is performed. The circuit 41 accurately detects the irradiation position of the laser beam.

In the CD-ROM 2, the division ratio table 46 is accessed by the detection result of the rough irradiation position of the laser beam during the seek, and by the detection result of the accurate irradiation position of the laser beam after the seek. The frequency dividing ratios M and N of the frequency dividing circuits 42 and 43 are set by the system control circuit 41 so as to correspond to the laser beam irradiation position, and are recorded in the frequency dividing ratio table 46 so as to correspond to the laser beam irradiation position. Frequency division ratio M and N
Changes the rotation speed.

As a result, the rotation speed of the CD-ROM 2 is
In accordance with the frequency division ratio recorded in the frequency division ratio table 46, from the innermost circumference to the outermost circumference within the operable frequency range of the integrated circuit of the reproduction system and within a smaller change range than when rotation is controlled by the CLV method. The rotation speed gradually changes from 4 times speed to 6 times speed. This allows the CD-ROM drive 40
In the case of the double speed reproduction, the variable range of the rotation speed is reduced as compared with the case of the CLV system, the time required for switching the rotation speed can be shortened by that much, and the seek time can be shortened. Is reduced.

According to the above construction, the rotation speed is gradually decreased from the inner circumference to the outer circumference within the frequency range in which the reproduction system can operate and within a change range smaller than that in the case where the rotation is controlled by the CLV method. By controlling the rotation speed of the spindle motor 3, it is possible to reduce the variable range of the rotation speed of the spindle motor 3 in the double speed reproduction as compared with the case of the CLV system, and increase the power consumption accordingly. It can be effectively avoided. Also, the time required for switching can be shortened, and the time required for access can be shortened as compared with the case of reproducing at 4 times speed by the CLV method, and the recorded data can be reproduced surely. it can.

Further, the rotation speed of the spindle motor 3 is set by setting the division ratios of the frequency dividing circuits 42 and 43 according to the contents of the frequency division ratio table 46, so that the rotation speed of the spindle motor 3 can be controlled easily and reliably. can do.

Further, the frequency dividing circuit 42 is used by switching between rough position information obtained by detecting the position of the optical pickup 4 and highly accurate position information obtained from the header.
By setting the frequency division ratios of 43 and 43, it is possible to improve the accuracy of spindle control as necessary, and it is possible to reliably reproduce the recorded data.

In the above embodiments, the linear velocities of the CD-ROM 2 are set to 4 × and 6 × for the innermost circumference and the outermost circumference, respectively, but the present invention is not limited to this. It is possible to set various linear velocities according to the above.

Further, in the above-mentioned embodiment, the case where the spindle motor is rotationally controlled so that the rotational speed is uniformly changed from the inner peripheral side to the outer peripheral side has been described.
The present invention is not limited to this, and the rotation speed of the spindle motor may be controlled so as to exhibit the changes shown by the symbols L2 and L3 in FIGS. 5 and 6, for example.

That is, when represented by the symbol L2, the rotation speed of the spindle motor is controlled by the CAV method on the inner peripheral side within a certain range, and the remaining outer peripheral side is controlled by the CLV method, whereby the operation of the integrated circuit of the reproduction system is performed. The rotation speed of the spindle motor 3 is controlled so that the rotation speed of the spindle motor 3 decreases on the outer peripheral side within a range of possible frequencies and within a change range smaller than that in the case where rotation control is performed by the CLV system as a whole. Is.

In this case, since the access time can be shortened by the CAV method, if the frequently accessed data is recorded in the rotation control range by the CAV method, the time required for the access as the entire CD-ROM drive can be shortened accordingly. You can Further, a conventional CAV type servo system and a CLV type servo system are combined to form a spindle servo system, and the operation of this servo system is CAV.
This characteristic can be realized by switching between the system and the CLV system, and thus the spindle servo system can be easily formed.

On the other hand, in the case of the symbol L3, the rotation speed of the spindle motor is controlled by the CAV method in the constant range on the inner peripheral side, and the remaining outer peripheral side is controlled by the method described above with reference to FIG. The spindle motor 3 is arranged so that the rotation speed of the spindle motor 3 decreases on the outer peripheral side within the range of the operable frequency of the integrated circuit of the reproduction system and within a change range smaller than that in the case of controlling the rotation of the whole by the CLV method. It controls the rotation speed of.

In this case as well, since the access time can be shortened by the CAV method as well, the frequently accessed data can be recorded in the rotation control range by the CAV method, and the access time of the entire CD-ROM drive can be shortened. it can. Further, in this case, in the remaining area, compared to the case where the rotation control characteristic is indicated by the symbol L2,
By being close to V control, the access time in this area can be shortened accordingly.

Furthermore, as described above with reference to FIGS. 3 to 6, not only linear velocity is changed linearly, but
The rotation speed of the spindle motor may be controlled so as to change in a quadratic function. In this way, the characteristics of the spindle servo system can be set so that, for example, when the seek width is the same on the inner circumference side and the outer circumference side, the power consumption, the time required to switch the rotation speed, and the like become equal.

Further, in the above-described embodiment, the reproduction position is roughly detected by the light spot position detection sensor, the reproduction position is accurately detected by the information of the header, and the two position detection results are switched and used. Although the case where the frequency ratio table is referred to has been described, the present invention is not limited to this.
If sufficient accuracy can be obtained for practical use, the frequency division ratio table may be referred to using only the reproduction position detected by the light spot position detection sensor.

Further, in the above embodiment, the case where the reproduction position is detected by the light spot position detection sensor and the information of the header is described, but the present invention is not limited to this.
The recording / reproducing position detecting means used in various disk devices can be widely applied. That is, some optical discs of this type are designed to perform tracking control based on what is called a pre-groove, which is a guide groove of a laser beam. In an optical disc device to which this optical disc is applied, a traverse obtained from this pre-groove is used. The recording / reproducing position may be detected based on the signal.

Similarly, when applied to a sample format optical disk, magnetic disk, etc., a traverse signal obtained from this sample format can also be used, and the recording / reproducing position can be detected by a scale arranged on the actuator. Good.

In the above embodiment, the case where the frequency division ratio table is referred to on the basis of the reproduction position detection result has been described, but the present invention is not limited to this, and in this type of optical disk device, the system control circuit is used. The frequency division table may be referred to by using the seek target set in the system control circuit as a reference by causing the optical pickup and the magnetic head to seek.

Further, in the above-mentioned embodiment, the case where the rotation speed is varied according to the frequency division ratio table has been described, but the present invention is not limited to this, and when the arithmetic processing capacity of the system control circuit is sufficient, The target rotation speed may be detected by arithmetic processing.

In the above embodiment, the case where the rotation speed of the spindle motor is controlled on the basis of the reproduction clock has been described, but the present invention is not limited to this, and FIG.
The invention can be widely applied to the case where the rotation speed of the spindle motor is directly detected and the rotation speed of the spindle motor is controlled as described above.

Further, in the above-mentioned embodiments, the case where the present invention is applied to the CD-ROM drive has been described, but the present invention is not limited to this, and various optical disk devices such as a magneto-optical disk device, and further a magnetic disk device. Disk device, etc.
It can be widely applied to various disk devices.

[0086]

As described above, according to the present invention, the rotation speed becomes higher than the standard rotation speed specified for the disc-shaped recording medium, and the rotation speed decreases at the outermost peripheral side, so that the linear velocity is By controlling the rotation speed of the spindle motor so as to increase, it is possible to reduce the increase in the linear velocity at the outermost circumference while increasing the data transfer speed as compared with the standard case. The operating speed of the signal processing circuit of the recording / reproducing system can be reduced without significantly changing the rotation speed of the motor, which allows the access time when the disk-shaped recording medium based on the CLV method is driven at double speed. Can be shortened, and an increase in power consumption can be effectively avoided.

[Brief description of drawings]

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

FIG. 2 is a diagram for explaining a frequency division ratio table of the CD-ROM drive shown in FIG.

3 is a characteristic curve diagram showing a relationship between a reproduction position and a clock frequency in the CD-ROM drive of FIG.

4 is a characteristic curve diagram showing a relationship between a reproduction position and a rotation speed in the CD-ROM drive of FIG.

FIG. 5 is a characteristic curve diagram showing a relationship between a reproduction position and a clock frequency according to another embodiment.

FIG. 6 is a characteristic curve diagram showing the relationship between the reproduction position and the rotation speed in the embodiment of FIG.

FIG. 7 is a block diagram showing a conventional CD-ROM drive.

8 is a characteristic curve diagram showing a relationship between a reproduction position and a clock frequency in the CD-ROM drive of FIG.

9 is a characteristic curve diagram showing a relationship between a reproduction position and a rotation speed in the CD-ROM drive of FIG.

FIG. 10 is a possible CD when the CAV method is applied
FIG. 6 is a block diagram showing a ROM drive.

[Explanation of symbols]

1, 30, 40 CD-
ROM drive 2 CD-
ROM 3, 31 Spindle motor 4 Optical pickup 13 Clock detection circuit 15, 33 Reference clock circuit 16, 17, 34, 35, 42, 43 Frequency division circuit 19 Phase comparison circuit 41 System control circuit 44 Position detection means 46 Frequency division ratio table

Claims (4)

[Claims] 1. A disc device for recording data on a disc-shaped recording medium according to a condition of constant linear recording density or reproducing data recorded according to a condition of constant linear recording density from the disc-shaped recording medium. A spindle motor that rotationally drives a recording medium, and a spindle motor control unit that controls a rotation speed of the spindle motor according to a recording position or a reproduction position, the spindle motor control unit defining the disc-shaped recording medium. In comparison with the standard rotational speed of the disk-shaped recording medium, the rotational speed of the disk-shaped recording medium is higher, and compared with the rotational speed of the disk-shaped recording medium when recording or reproducing the innermost circumference, The rotation speed of the disk-shaped recording medium when recording or reproducing the outermost circumference is reduced,
Further, as compared with the linear velocity of the recording position or the reproducing position when recording or reproducing the innermost circumference, the linear velocity of the recording position or the reproducing position when recording or reproducing the outermost periphery increases,
A disk device characterized by controlling the rotation speed of the spindle motor. 2. The spindle motor control means converts the data into a recording signal, or a reproduction signal into a data processing system for converting the reproduction signal into the data, within the operable frequency of a signal processing system. The spindle motor is configured so that the linear velocity of the recording position or the reproducing position when recording or reproducing the outermost periphery increases as compared with the linear velocity of the recording position or the reproducing position when recording or reproducing the inner periphery. 2. The disk device according to claim 1, wherein the rotation speed of the disk drive is controlled. 3. The spindle motor control means sequentially or stepwise decreases the rotation speed from the innermost recording position or reproducing position to the outermost recording position or reproducing position, 3. The rotation speed of the spindle motor is controlled to control the rotation speed of the spindle motor.
The disk device described in 1. 4. The spindle motor control means holds the rotational speed at a constant value in a prescribed range from the innermost recording position or reproducing position to the outermost recording position or reproducing position, 3. The disk device according to claim 1, further comprising controlling the rotation speed of the spindle motor so that the linear velocity at the recording position or the reproducing position becomes a constant value.