JPH1125587A - Device for reproducing disk and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable steady reproduction in an operational limit determined by a limit of a load and vibration of a disk motor and a limit of data processing performance. SOLUTION: When a disk is to be steadily reproduced, reproduction is carried out by inner circumferential part CAV/outer circumferential part CLV operation (operation on an A-B-C line), and during a fixed period after starting a search in the outer circumferential direction toward the end point of the outer circumferential part, the CAV operation is performed in the outer circumferential part at a revolving speed of the outermost circumference at the time of the outer circumferential part CLV operation, and the CLV operation (operation on a C-D-A line) is performed in the inner circumferential part at a reproducing speed of the innermost circumference at the time of the inner circumferential part CAV operation. Even when a reproducing speed at the time of steady reproduction of the outer circumferential part is equalized to the limit of the data processing performance, a reproducing speed during a search does not exceed the limit of the data processing performance to increase a search speed. Then, since the CLV operation is performed in the inner circumferential part, the reproducing speed is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM
The present invention relates to a disk reproducing apparatus for reproducing an optical disk such as a VD-ROM and a reproducing method thereof.

[0002]

2. Description of the Related Art Recently, a CD-ROM drive used as a peripheral device of a computer is an 8 × speed, a 12 × speed, or the like.
Further, as a method for realizing high-speed reproduction such as 16 × speed and 32 × speed, a constant linear velocity (CLV: Constant Linear
A disk on which a signal is recorded by a velocity (Velocity) method has a constant rotation speed at the inner periphery (CAV: Constant Angular Velocit).
y), a method of reproducing with the CLV in the outer peripheral portion is being studied. In a reproducing apparatus that reproduces a disk on which a signal is recorded in the CLV format at a high speed, the number of rotations of the disk motor changes according to a read track position on the disk radius, and increases proportionally from the outer peripheral side to the inner peripheral side of the disk. Draw a line. Therefore, when the proper rotation speed at the reproduction position before the track jump and the proper rotation speed at the reproduction position after the track jump are significantly different during the track jump, the motor will accelerate or decelerate, so that the proper rotation speed after the track jump is reduced. The time required for convergence increases. In order to solve this problem, there is a method of reducing the average access time at the time of a track jump by using a disk motor having good acceleration / deceleration performance that generates a high torque.However, using such an expensive disk motor requires
This is a great hindrance when trying to realize a small and inexpensive playback device.

As a method of realizing high-speed reproduction, there is also a method of reproducing data by the CAV method. In this case, however, the number of rotations of the disk motor is constant at all track positions on the disk, so that a disk motor having good acceleration / deceleration performance is used. No need to use. However, in CAV, the data reproduction speed changes greatly from the outer circumference to the inner circumference of the disk. Therefore,
When the disk motor is rotated at a high rotation speed to realize high-speed reproduction, a higher data processing capability of the signal processing circuit is required. However, there is a limit to the maximum oscillation frequency of the clock generator that determines the performance of the signal processing circuit, and therefore, there is a limit to improving the reproduction speed of the disk reproducing device. Therefore, in the disc reproducing method, the data area on the disc is divided in advance into an inner peripheral portion and an outer peripheral portion including this track position at an arbitrary track position, and a signal is read from the outer peripheral portion of the disc. , CLV, and reading from the inner periphery of the disc is performed by CAV (Japanese Patent Application No. 8-117).
567). This method (hereinafter referred to as inner peripheral portion CAV / outer peripheral portion C)
In the case of the LV system, the maximum number of revolutions of the disk motor can be reduced, and the burden on the disk motor and the problem of vibration can be reduced.

[0004]

FIG. 8 shows an inner peripheral portion CAV.
FIG. 14 is a characteristic diagram showing a relationship between a data area reproduction position and a data reproduction speed when reproducing a disk by the / peripheral part CLV method. As described above, in this method, the maximum rotation speed of the disk motor can be reduced by reproducing the inner peripheral portion with CAV and the outer peripheral portion with CLV, thereby reducing the load and vibration problems of the disk motor. In addition, CL
By using the V method, it is guaranteed that the reproduction signal rate at the time of reproducing the disk is within the range of the data processing capability. However, in this method, when searching the outer periphery, the reproduction signal rate becomes higher than when the outer periphery is CLV-reproduced.
If the reproduction is set, the reliability of the CD synchronization signal and the subcode data is lost. As a result, there is a possibility that the search may be delayed or an abnormal operation may be performed. Also, in order to avoid this, if the data is set to be played back at a playback speed that adds a margin to the data processing capacity limit, the data processing capacity limit cannot be used effectively, and the playback of the outer peripheral portion of the disk will not be possible. Speed decreases. Also, in the DVD-ROM system, the disk is recorded in the CLV format, and a similar problem may occur if the drive speed is increased in the future. The present invention has been made in view of such circumstances, and provides a disk reproducing apparatus and a reproducing method capable of constantly reproducing an operation limit determined by a load and a vibration limit of a disk motor and a data processing capacity. I do.

[0005]

According to the present invention, in the case where the disk is constantly reproduced, the inner peripheral portion CAV / the outer peripheral portion CLV is used.
For a certain period of time after the reproduction by the operation and the start of the search in the outer circumferential direction ending at the outer circumferential portion, the outer circumferential portion is CAV-operated at the rotation speed at the outermost circumference during the outer circumferential portion CLV operation, and CLV at inner circumference at playback speed at innermost circumference during CAV operation
It is characterized by being operated. In this case, the track position for dividing the data area on the disk into an inner peripheral portion and an outer peripheral portion when the disk is constantly reproduced is:
The first position, and the track position that divides the data area on the disk for a certain period of time from the start of the search in the outer circumference direction with the outer circumference as the end point into the inner circumference area and the outer circumference area is the second position. It is characterized by the following.

That is, the disk reproducing apparatus of the present invention comprises:
A disk on which data is recorded at a constant linear velocity, a driving unit for rotating the disk, a photoelectric conversion unit for optically reading data recorded on the disk, and converting the data into an electric signal; and An amplifier for amplifying the supplied electric signal, a data slice circuit for generating a binarized signal from the amplified electric signal, and a clock signal corresponding to a change in data reproduction speed based on the binarized signal. And a signal processing circuit for demodulating the binary signal in accordance with the clock signal and reproducing data, and divides a data area on the disk into an inner peripheral portion and an outer peripheral portion. Arbitrary track position is first
And the second position are provided. When data is constantly read from the inner peripheral portion divided by the first position, the disk motor is controlled at a constant rotation speed, and the data is read out at the first position. The disk motor is controlled at a constant linear velocity when data is constantly read from the outer peripheral section, and the linear velocity is constant when reading data from the inner peripheral section at the second position during a search period. And controlling the disk motor at a constant rotation speed when reading an outer peripheral portion divided by the second position.

Also, the reproducing method of the disk reproducing apparatus according to the present invention comprises the steps of optically reading data recorded on the disk at a constant linear velocity, converting the data into an electric signal, and amplifying the electric signal. Generating a binarized signal from the amplified electric signal; generating a clock signal according to a change in data reproduction speed based on the binarized signal; Demodulating the binarized signal and reproducing the data, wherein in the reproducing the data, an arbitrary track position that divides a data area on the disk into an inner peripheral portion and an outer peripheral portion is defined as a first track position. The disk motor is controlled at a constant rotation speed when data is constantly read from an inner peripheral portion divided by the first position, and the disk motor is divided by the first position. Sa Constantly controls the disk motor at a constant linear velocity when reading the data in that the outer peripheral portion,
In addition, an arbitrary period is set which starts from the start of the search in the outer circumferential direction ending at the outer circumferential portion divided at the second position, and during that time, the inner circumferential portion divided at the second position is set. When reading the data, the disk motor is controlled at a constant linear velocity, and when reading the outer peripheral portion divided at the second position, the disk motor is controlled at a constant rotation speed.

In the present invention, after starting the search in the outer peripheral direction ending at the outer peripheral portion, the reproduction is performed by the inner peripheral portion CLV operation for a certain period of time and the operation is performed by the outer peripheral portion CAV, thereby reducing the load and vibration limit of the disk motor. The operation limit determined by the limit of the data processing capability can be used as a characteristic for steady reproduction. Further, even if the playback speed when the outer peripheral portion is constantly played back is equal to the limit of the data processing capability, the search speed during the search does not exceed the limit of the data processing capability, and the search speed is increased. Furthermore, since the inner peripheral portion is operated by the CLV operation as compared with the case where the entire disc is reproduced by the CAV operation, the reproduction speed can be improved. INDUSTRIAL APPLICABILITY The present invention can be applied to a disc reproducing apparatus of an optical disc system based on a CLV recording method such as a CD-ROM and a DVD-ROM.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a CD-ROM reproducing apparatus centered on a servo section and a CD signal processing section. A signal read from the disk 1 by the optical pickup 2 is supplied to the RF amplifier 3. The RF amplifier 3 extracts a focus error signal and a tracking error signal from the output of the optical pickup 2 and supplies the focus error signal and the tracking error signal to the focus / tracking control circuit 4 and a slice / PLL circuit (data slice circuit / PP).
The amplified electric signal RF is supplied to the L circuit 5. Also,
A lens control signal for the optical pickup 2 is generated based on the focus error signal and the tracking error signal, and supplied to the optical pickup 2. The feed motor control circuit 6
A feed motor drive signal is generated from a tracking error component supplied from the focus / tracking control circuit 4 and a search instruction signal supplied from the system controller 7, and the feed motor drive signal controls the feed motor 9.

The slice / PLL circuit 5 converts the RF signal into 2
At the same time, the EFM signal is formed to generate a PLL clock PLCK synchronized with the EFM signal for reading the EFM signal. The binarized EFM signal is supplied to the CD signal processing circuit 8. The PLCK is supplied to the CD signal processing circuit 8. The CD signal processing circuit 8
Using the LCK, a CD synchronization signal is detected, and based on this, data is separated and EFM demodulation is performed. Then, the CD signal processing circuit 8 extracts only the subcode data from the demodulated data and supplies it to the system controller 7. further,
In response to an audio / ROM switching instruction signal from the system controller 7, the CD signal processing circuit 8
Data correction processing is performed in accordance with K or an X'tal clock supplied from the clock generator 11. PLC
When the correction process is performed in accordance with K, the variable speed reproduction of the related art is performed. Further, the detected frame synchronization signal PFCK of the CD is supplied to the disk motor control circuit 12.

The disk motor control circuit 12 includes a first control data and write signal supplied from the system controller 7, a second control data and write signal, an operation mode instruction signal, and a P signal supplied from the CD signal processing circuit 8.
LL frame synchronization signal PFCK, clock generator 1
1 to generate a disk motor control signal based on the X'tal system clock supplied from 1 and the FG pulse output from the FG pulse detection circuit 14 for detecting the rotation speed of the disk motor 13. To supply. Further, based on the frame synchronization signal PFCK and the FG pulse, the first control data, and the write signal, an inner / outer periphery division signal for dividing the inner and outer periphery of the disk is generated, and supplied to the system controller 7. The disk motor control circuit 12 responds to the operation mode instruction signal given by the system controller 7 to control the inner peripheral portion CAV / the outer peripheral portion CLV.
, Or whether to reproduce with the inner peripheral portion CLV / outer peripheral portion CAV.

The system controller 7 controls the operation of the entire CD-ROM drive, such as search, reproduction, setting change, and the like. Further, the system controller 7 determines whether the main data is audio data or CD-ROM data based on the subcode data demodulated by the CD signal processing circuit 8, and outputs an audio / ROM switching instruction signal.
When a CD-ROM is reproduced, an operation mode instruction signal is supplied to the disk motor control circuit 12 based on the inner / outer circumference division signal supplied from the disk motor control circuit 12 and the search track position determined by itself. When the inner / outer perimeter division signal indicates that the inner perimeter is being reproduced, and a search to the outer perimeter is performed, and when the inner / outer perimeter division signal indicates that the outer perimeter is being reproduced, the outer perimeter direction is indicated. When performing a search for the search, the operation mode of the inner circumference CLV and the outer circumference CAV is instructed, and this is held for a certain period. When the reproduction is performed regularly, the operation mode of the inner circumference CAV and the outer circumference CLV is instructed. When switching the operation mode instruction signal, CA
Revolution speed of V control, playback speed of CLV control and CAV / C
The first control data and write signal and the second control data and write signal for determining the LV switching track position are supplied to the disk motor control circuit 12 again to change the internal register value.

The switching of the selector 15 is performed by an audio / ROM switching instruction signal output from the system controller 7. The selector 15 supplies main data to the audio circuit 16 when audio is instructed by the instruction signal, and supplies main data to the CD-ROM signal processing circuit 17 when ROM is instructed. The audio circuit 16 converts the main data into an audio signal and outputs the audio signal. The CD-ROM signal processing circuit 17 receives the CD supplied from the CD signal processing circuit 8.
-Decrypt and correct the ROM data and transfer it to the host computer. FIG. 2 is a block diagram showing a configuration of the disk motor control circuit 12 when reproducing a CD-ROM.

Hereinafter, the configuration of the disk motor control circuit 12 will be described. The disk motor control circuit 12 counts a signal period, which is a controlled amount in the disk motor control, with a clock generated from the system clock, and generates a disk motor control signal proportional to an error with respect to a reference value determined by a target reproduction speed and a target rotation speed. The part to be generated is centered. The period, which is the controlled amount, is obtained by dividing the frequency of the FG pulse or the frame synchronization signal by the frequency divider 2.
Is used as a preset timing of the counter 2 and an output timing signal to the D / A converter 19. When the disk motor 13 is CAV controlled, the period of the FG pulse is the controlled variable, and when the CLV control is performed, the output of the frequency divider 2 is the controlled variable. A clock for counting a signal period as a controlled variable is supplied to a counter 2 from a frequency divider 1 that divides a system clock. The counter 2 has a preset value of the register 2 for detecting an error with respect to the reference value, and counts one cycle of the output signal of the selector 18 by the output of the frequency divider 1. Since the count value of the counter 2 must be zero as data to be supplied to the D / A converter 19 when there is no error in the controlled signal with respect to the reference value of the controlled signal, the value of the register 2 is set at the target rotation speed or reproduction speed. A value obtained by dividing the cycle of the output of the selector 18 during reproduction by the cycle of the output of the frequency divider 1 is set by the second control data and the write signal.

The selector 18 operates according to an instruction from the control circuit, and operates according to the table shown in FIG. The control circuit not only outputs the switching signal of the selector 18 but also outputs the inner and outer peripheral division signals. The output also operates according to the chart of FIG. In the frequency divider 2, the frequency division number is set by the value of the register 1. When the value of the register 1 becomes equal to the count value of the counter 1, the frequency of the FG pulse and the frame synchronization signal are divided by the frequency divider 2. The periods of things become equal. By doing so, even when the selector 18 switches when the value of the register 1 becomes equal to the count value of the counter 1, the value of the register 2 is not changed and the value of the register 2 is not changed, and the CLV is not changed from the CLV.
The control method can be smoothly changed to V. The counter 1 uses the frame synchronization signal PFCK as a count clock,
This is a counter that counts up pulses as reset and output timing signals. The counter 1 counts one cycle of the FG pulse by the frame synchronization signal, and supplies the count value to the control circuit 20. When the count value of the counter 1 and the value of the register 1 are exchanged, the control circuit 20 changes the inner / outer-peripheral division signal and simultaneously selects the selector 1.
8 to change the control method of CAV or CLV.

FIG. 4 is a characteristic diagram showing the relationship between the disk reproduction position and the data reproduction speed according to the present invention. CD-ROM
When the system controller 7 intends to constantly reproduce from the inner peripheral portion to the outer peripheral portion, the system controller 7 instructs the operation mode of the inner peripheral portion CAV and the outer peripheral portion CLV. At this time, the first control data and the write signal and the second control data and the write signal are reset to set the rotation speed of the inner peripheral portion CAV and the reproduction speed of the outer peripheral portion CLV. Is also moved. The characteristics of the inner peripheral portion CAV and the outer peripheral portion CLV operation can be superimposed on the limit line of the rotation speed determined by the load and the limit of the vibration of the disk motor and the limit line of the reproduction speed determined by the limit of the data processing capability. The limit performance of the device can be used effectively. When performing a search from the inner peripheral portion to the outer peripheral portion and from the outer peripheral portion to the outer peripheral portion in the outer peripheral direction, the system controller 13 instructs the operation mode of the inner peripheral portion CLV and the outer peripheral portion CAV.
At this time, the first control data and the write signal and the second control data and the write signal are reset to set the reproduction speed of the inner peripheral portion CLV and the rotation speed of the outer peripheral portion CAV, and the inner and outer peripheral portions are divided. The sectioning position also moves. At this time, the outer peripheral portion is determined by the rotational speed at the outermost periphery during the outer peripheral portion CLV operation.
V operation, and the CLV operation is performed on the inner periphery at the reproduction speed at the innermost periphery during the operation of the inner periphery CAV.

In this operation mode, a search from the inner peripheral portion to the outer peripheral portion or a search from the outer peripheral portion to the outer peripheral portion is performed and then maintained for a certain period of time. To prepare for a search in the outer peripheral direction. By doing so, the reproduction speed during the search does not exceed the limit of the data processing capability, and the search is accelerated. Also, CA
The reproducing speed can be improved in the inner peripheral portion as compared with the case where the V operation is performed on the entire disk, and the reproducing speed can be improved in the outer peripheral portion as compared with the case where the CLV operation is performed on the entire disk. In FIG. 4, the disc reproducing operation is performed according to the operation characteristic line (ABC-
D). The steady reproduction operates along the operation characteristic line (ABC) as indicated by the dotted line, and the reproduction during the search operates along the operation characteristic line (ADC) as indicated by the dotted line. Operate. The inner and outer division positions are shown at points B and D, and points E and F projected on the horizontal axis (disc reproduction position) correspond to the first and second positions of the inner and outer division positions, respectively. Express.

Hereinafter, a setting method for realizing the characteristics of FIG. 4 by the disk motor control circuit of FIG. 2 will be described. First, the case of operating in the inner peripheral portion CAV and the outer peripheral portion CLV (normal operation) will be described. The innermost disk radius r1 is 0.023 (m), the linear velocity LV of the disk data is 1.2 (m / s), and the innermost reproduction speed N1 is 8
(Double speed), the rotation speed R1 of the inner peripheral portion CAV is N1
LV / (2π · r1) 66.43 (rotation /
Seconds). At this time, assuming that the number of FG pulses NF when the disk makes one rotation is 6 (number), the frequency of the FG pulse is 398.58 (Hz) represented by NF · R1.
One cycle of the FG pulse is counted by the output of the frequency divider 1 by the counter 2, and the frequency of the FG pulse is 398.58 (Hz).
Since the count value at the time must be zero,
The frequency FMCK of the system clock is set to 16.9344
(MHz) and the frequency division number n1 of the frequency divider 1 is 32 (frequency division), the value R21 of the register 2 is FMCK / (R1 · N
F · n1), which is 1327.7. This is an absolute value, and the polarity is determined such that the loop of the disk motor servo has negative feedback.

The frequency division number n1 of the frequency divider 1 should be determined by how precisely the period of the FG pulse is controlled. Then, a value R11 of the register 1 is obtained to determine a position (first position E) at which the inner peripheral portion CAV is switched to the outer peripheral portion CLV. When the playback speed N2 becomes 16 (double speed) in the inner peripheral portion CAV operation, switching to CLV results in
At that time, the number of frame synchronizing signals included in one cycle of the FG pulse becomes the value R11 of the register 1, and 7350 · N2 / (R
1 · NF), which is 295. Here, 7350
Is the frequency of the frame synchronization signal PFCK when reproduced at CLV, 1 × speed. Next, the inner peripheral portion CLV and the outer peripheral portion C
A case of operating in AV (search operation) will be described. CLV, reproduction speed N2 = 16 (double speed) and radius r2 =
The rotational speed when the outermost circumference of 0.058 (m) is reproduced is C
Assuming that the AV operation is performed, the rotation speed R2 is N2 · LV /
It is represented by (2π · r2), which is 52.69 (rotation / second). When the frequency of the FG pulse is NF · R2 (Hz), the count value of the counter 2 must be zero. Therefore, the value R22 of the register 2 is FMCK / (NF · R2
N1) is 1673.9.

Then, the CAV is obtained at the rotation speed R2 (rotation / second).
When the reproduction speed is set to N1 = 8 (double speed) when the reproduction is performed, the inner peripheral portion CLV operation is performed.
Is expressed as 7350 · N1 / (R2 · NF) and becomes 186. The track position (second position F) that divides the inner and outer circumferences is determined by the value of the counter 1 for counting the number of frame synchronization signals during one cycle of the FG pulse and the value R of the register 1.
This is a read track when the size of 1X is exchanged. Inner / outer circumference section radius position r is LV / NF / R1X /
(2π · 7350). The above inner peripheral portion CAV,
In the setting of the outer peripheral portion CLV, R1X = 295 is substituted and r
(Position of E) = 0.046 (m). In the setting of the inner peripheral portion CLV and the outer peripheral portion CAV, R1X = 186 is substituted and r (the position of F) becomes 0.029 (m). FIGS. 5 and 6 show the counter 2 used in FIG. 2 for realizing this setting and its operation timing chart, respectively, and FIG. 7 shows a control circuit. The circuit of the counter 2 is, for example, a counter of a synchronous preset synchronous up-count, and delivers the count value to the D / A converter 19 near the rising edge of the output of the selector 18 and simultaneously presets the output of the register 2.

The value of the register 2 is equal to the value of R2
1. Write the two's complement of R22. For example, if R21 is 1
If 328 (decimal) is set, AD0 (hexadecimal) is written. Further, in this embodiment, when the non-control amount is lower than the reference value, the counter output becomes a negative value, so that the D / A converter 1 is controlled so that the disk motor servo loop becomes a negative feedback.
At 9 adjust the polarity. When the operation mode instruction signal is H, the control circuit 20 indicates that the inner CAV and outer CLV operations are instructed, and when the operation mode instruction signal is L, the inner circuit CLV and the outer CAV operation are instructed. Means that. The selector 18 is a selector 1 of the control circuit 20.
When the output to 8 is L, the FG pulse is selected, when it is H, the output of the frequency divider 2 is selected, and when the output signal is L, it means that the inner portion is being reproduced. , H means that the outer peripheral portion is being reproduced. When the output of the register 1 is smaller than the output of the counter 1, the control circuit 20 sets the inner / outer peripheral division signal to H, and otherwise to L. When the operation mode instruction signal is H, a signal equal to the inner / outer peripheral division signal is output to the selector 18, and when the operation mode instruction signal is L, a signal obtained by inverting the inner / outer peripheral division signal is output to the selector 18. The present invention can basically apply the same system to a DVD-ROM, and the same effect can be obtained if the speed of the DVD-ROM drive is increased in the future.

[0022]

According to the disk reproducing apparatus of the present invention, C
After starting the search in the outer circumferential direction ending at the outer circumferential portion where the LV operation is to be performed, it is operated at the inner circumferential CLV and the outer circumferential CAV for a certain period of time, so that the limit of the load and vibration of the disk motor and the limit of the data processing capacity are determined. The operation limit to be performed can be a characteristic at the time of steady reproduction. Further, even if the reproduction speed when the outer peripheral portion is constantly reproduced is equal to the limit of the data processing capacity, the reproduction speed during the search does not exceed the limit of the data processing capacity, and the search speed is increased. Further, compared to the case where the entire disc is reproduced by the CAV operation, the reproduction speed can be improved by performing the CLV operation on the inner peripheral portion.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of a CD-ROM playback device according to the present invention.

FIG. 2 is a block diagram of a disk motor control circuit used in FIG. 1;

FIG. 3 is an operation diagram illustrating an operation of an operation mode instruction signal used in FIG. 2;

FIG. 4 is a characteristic diagram showing a relationship between a disk reproduction position and a data reproduction speed of the disk reproduction device of the present invention.

FIG. 5 is a circuit diagram of a counter 2 used in FIG. 2;

FIG. 6 is an operation timing chart of a counter 2 used in FIG. 2;

FIG. 7 is a circuit block diagram of a control circuit used in FIG. 2;

FIG. 8 is a characteristic diagram showing a relationship between a disk reproduction position and a data reproduction speed of a conventional disk reproduction device.

[Explanation of symbols]

1 ... Disc, 2 ... Pickup, 3
... RF amplifier, 4 ... Focus / tracking control circuit, 5 ... Slice PLL circuit, 6 ...
・ Feed motor control circuit, 7 ・ ・ ・ System controller, 8 ・ ・ ・ CD signal processing circuit, 9 ・ ・ ・ Feed motor, 11 ・ ・ ・ Clock generator, 12 ・ ・ ・ Disk motor control circuit, 13 ・ ・ ・Disk motor, 1
4 ... FG pulse detection circuit, 15, 18 ... Selector, 16 ... Audio circuit, 17 ... C
D-ROM signal processing circuit, 19: digital / analog converter (D / A), 20: control circuit.

Claims (5)

[Claims] 1. A disk on which data is recorded at a constant linear velocity, a drive unit for rotating the disk, and optically reading data recorded on the disk,
A photoelectric conversion unit that converts the electric signal into an electric signal; an amplifier that amplifies the electric signal supplied from the photoelectric conversion unit; a data slice circuit that generates a binarized signal from the amplified electric signal; A PLL circuit that generates a clock signal according to a change in the data reproduction speed based on the clock signal; and demodulates the binary signal according to the clock signal.
A signal processing circuit for reproducing data, wherein an arbitrary track position for dividing a data area on the disc into an inner peripheral portion and an outer peripheral portion is defined as a first position and a second position.
When reading data constantly at the inner peripheral portion divided at the first position, the disk motor is controlled at a constant rotation speed, and the outer peripheral portion divided at the first position is constantly controlled. When reading data, the disk motor is controlled at a constant linear velocity, and during a search period, when reading data at an inner peripheral portion divided by the second position, the disk motor is controlled at a constant linear velocity, A disk reproducing apparatus characterized in that the disk motor is controlled at a constant rotation speed when reading an outer peripheral portion divided by a second position. 2. An arbitrary period starting from the start of a search in an outer peripheral direction ending at an outer peripheral portion divided at the second position is set, and during that period, an arbitrary period is defined at the second position. When reading data of the inner peripheral portion, the disk motor is controlled at a constant linear velocity, and when reading the outer peripheral portion divided at the second position, the disk motor is controlled at a constant rotation speed. The disk playback device according to claim 1. 3. The outer peripheral portion is operated at a constant rotational speed at the rotational speed at the outermost periphery during the constant linear velocity operation of the outer peripheral portion, and the outer peripheral portion is operated at the innermost periphery during the constant rotational speed operation at the inner peripheral portion. 2. The disk reproducing apparatus according to claim 1, wherein an inner circumference is operated at a constant linear velocity at a reproducing speed. 4. A fixed period starting from a search in an outer peripheral direction ending at an outer peripheral portion divided by the second position is started at a rotational speed at an outermost periphery during the constant operation of the outer peripheral linear velocity. 2. The disk reproducing apparatus according to claim 1, wherein the unit is operated at a constant rotation speed, and the inner periphery is operated at a constant linear velocity at a reproduction speed at an innermost periphery during the operation at the constant inner periphery rotation speed. apparatus. 5. A step of optically reading data recorded on the disk at a constant linear velocity and converting the data into an electric signal; amplifying the electric signal; and binarizing the amplified electric signal. Generating a signal; generating a clock signal corresponding to a change in the data reproduction speed based on the binarized signal; demodulating the binarized signal according to the clock signal to reproduce data In the step of reproducing the data, providing two arbitrary track positions, a first position and a second position, for dividing the data area on the disk into an inner peripheral portion and an outer peripheral portion, The first
The disk motor is controlled at a constant rotation speed when data is constantly read at an inner peripheral portion divided at the position, and a linear velocity when data is constantly read at an outer peripheral portion divided at the first position. The disc motor is controlled to be constant, and an arbitrary period starting from the start of the search in the outer peripheral direction ending at the outer peripheral portion divided at the second position is set, and during that period, the second period is set. The disk motor is controlled at a constant linear velocity when reading the data of the inner peripheral portion divided at the position, and the disk motor is controlled at a constant rotation speed when reading the outer peripheral portion divided at the second position. A reproducing method for a disk reproducing apparatus, comprising: