JPH10334580A - Optical disk recording and/or reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the rotation of an optical disk without generating a speed difference between a rotating speed when the recording optical disk is not read or not written and a rotating speed when reading or writing of the optical disk is resumed at the time of intermittently reading or writing the optical disk. SOLUTION: At the time of changing the optical disk 1 from the control state at CLV(constant linear velocity) to the control state at CAV(constant angular velocity), an FG cycle of the optical disk 1 under rotation at CLV is fetched in a reference value register 32. At the time of controlling the optical disk 1 at CAV, the rotating speed of the optical disk 1 is controlled at CAV by using the FG cycle fetched in the reference value register 32 at the time of rotating at CLV. By this method, a speed difference between a rotating speed of the optical disk when the optical disk 1 is controlled at CAV and a rotating speed when reading of the optical disk 1 is resumed is almost eliminated, and 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 an optical disk recording and / or reproducing apparatus, and in particular, to an MD (Mini
Disc) The present invention relates to an optical disk recording and / or reproducing apparatus in which writing / reading of an optical disk is performed intermittently as in a recording / reproducing apparatus.

[0002]

2. Description of the Related Art For example, a cartridge having a diameter of 6
2. Description of the Related Art An MD (Mini Disc) recording / reproducing apparatus which compresses and records / reproduces digital audio data on a 4 mm optical disk or a magneto-optical disk has been widely used. M
The D recording / reproducing apparatus compresses and records digital audio data, thereby making it possible to record digital audio data having a recording time comparable to that of a CD (Compact Disc), for example, using an optical disk having a diameter of 64 mm.
MDC is used as a compression method for digital audio data.
ATRAC (Adaptive Transform Aco) that compresses data based on T (Modified Discrete Cosine Transform)
A system called ustic coding is used.

[0003] In an MD recording / reproducing apparatus, at the time of reproduction, recorded data on an optical disk is read out.
After EFM demodulation and error correction processing are performed, they are stored in a buffer memory. Then, the output of the buffer memory is sent to the ATRAC decoder and expanded.

[0004] The transfer rate of a reproduction signal from an optical disc when reproduction is performed by an MD recording / reproducing apparatus is 1.4 Mbi.
The data transfer rate required by the ATRAC decoder is 0.3 Mbit / s, while the rate is t / s. Therefore, the data reproduced from the optical disk is written into the buffer memory at a speed of 1.4 Mbit / s, and is read at a speed of 0.3 Mbit / s. Since the transfer speed of data from the optical disk is faster than the transfer speed of data to the ATRAC decoder, data accumulates in the buffer memory. When a certain amount of data is accumulated in the buffer memory, the reading of data from the optical disk is stopped, and the reading of data from the buffer memory is continued. Then, when the data in the buffer memory becomes smaller than the predetermined amount, reading of data from the optical disk is started again.

As described above, in the MD recording / reproducing apparatus,
Reading data from the optical disk is performed intermittently. During a period in which the buffer memory has a predetermined amount of data or more and data is not being read from the optical disk, data reading from the buffer memory and AT
Only the RAC decoding process is performed. Therefore, when data is read intermittently from the optical disk in this manner, during the period in which the optical disk is not being read, the buffer memory read processing, the ATRAC decode processing, and the reproduction data Is converted into an analog signal, and only the portion of the D / A conversion process of outputting the analog signal needs to be operated.
A laser beam driving circuit, a servo circuit, a demodulation circuit, and the like can be turned off. If the other circuit portions are turned off during a period in which the optical disk is not being read, power consumption can be reduced accordingly.

By the way, data is recorded at a constant linear velocity on an optical disk or a magneto-optical disk of an MD system. When reading data from an optical disk, it is necessary to control the rotation of the disk at a constant linear velocity. Such control is unnecessary when the reading of data is not performed. Therefore, when the optical disk is not being read, the rotation of the optical disk is turned off,
It is conceivable to reduce the power consumption by turning off the spindle servo.

However, if the rotation of the optical disk is stopped while the optical disk is not being read, a large current is required to restart the rotation of the optical disk, and the power consumption is rather increased. When the spindle servo is turned off, the rotation speed of the optical disk during that time becomes unstable, so that the speed difference from the rotation speed when restarting the rotation of the optical disk becomes large. For this reason, a large current is required until the rotation speed of the optical disk is controlled to a predetermined rotation speed, which results in an increase in power consumption. Therefore, the MD recording / reproducing apparatus intermittently reads the optical disk during reproduction, controls the optical disk at a constant linear velocity when reading the optical disk, and restarts reading the optical disk when not reading the optical disk. It is desired that the optical disk be controlled at a constant angular velocity so as to have a speed that does not cause a speed difference from the rotational speed at that time.

Therefore, the optimum angular velocity is calculated from the address on the optical disk from which the reading is being performed, and when the state of reading the optical disk is switched to the state where the reading of the optical disk is not performed, the optimum angular velocity is calculated. Accordingly, it is conceivable to control the optical disk so that the angular velocity is constant.

[0009] That is, FIG.
FIG. 5 shows an example of a conventional CAV servo circuit when controlling with V. FIG. As shown in FIG. 4, the CAV servo circuit includes an FG cycle measuring circuit 111 for measuring the cycle of the FG signal from the spindle motor 102, and a reference value register 11
2, a comparison circuit 113, a low-pass filter 114, and a driver 115, and a reference value calculation circuit 116 for calculating an optimum reference value for the reference value register 112 is provided. The reference value register 116 receives an address from a terminal 117.

An FG signal is generated from the spindle motor 102 in accordance with the rotation speed of the spindle motor 102. This FG signal is supplied to the FG cycle measurement circuit 111. The FG cycle measuring circuit 111 measures the cycle of the FG signal. The angular velocity of the spindle motor 102 is detected from the period of the FG signal. This FG cycle detection circuit 1
11 is supplied to the comparison circuit 113.

The output of the reference value register 112 is supplied to the comparison circuit 113. The output of the reference value calculation circuit 116 is supplied to the reference value register 112. The reference value calculation circuit 116 calculates an optimum reference value based on the address from the input terminal 117.

That is, if the address of the data read position is known, the radial distance of that position on the optical disk can be known. Therefore, from the radial distance on the optical disk and the linear velocity of the optical disk, the rotational speed when the optical disk 1 is rotated by the CLV at that position can be calculated. A reference value of the rotation speed is output from the reference value calculation circuit 116 in accordance with the calculated value. This reference value calculation circuit 1
The 16 outputs are supplied to a reference value register 112.

In a comparison circuit 113, a reference value register 112
Is compared with the current cycle of the FG signal of the spindle motor 102, and a speed error and a phase error are obtained. The output of the comparison circuit 113 is supplied to the low-pass filter 114 and the driver 1
15 and supplied to the spindle motor 102.

As described above, the optimum angular velocity for each address is obtained by the reference value calculation circuit 116, and when the state of reading from the optical disk is switched to the state in which reading of the optical disk is not performed, the optimum angular velocity obtained by the calculation is obtained. By controlling the optical disc so that the angular velocity is constant according to the angular velocity, a difference in rotation speed between when the optical disc is not read and when the optical disc is resumed is prevented from occurring. be able to.

[0015]

However, the linear velocity of the disk in the MD system is 1.2 m / s to 1.m.
There is variation in the range of 4 m / s. In other words, the linear velocity is 1.4 m / s for the 60-minute disk, and 1.2 m / s for the 72-minute disk. As described above, when the optical disk is controlled so as to have a constant angular velocity by obtaining the optimum angular velocity corresponding to the address, the reference value calculation circuit 116 calculates the reference value of the rotational speed from the address and the linear velocity of the disk. It is calculated by calculation. Therefore, as described above, when the disk is controlled so as to have a constant angular velocity by obtaining the optimum angular velocity corresponding to the address, it is necessary to determine the optimum angular velocity unless such linear velocity variation is considered. Can not.

Incidentally, in the MD recording / reproducing apparatus, writing on the optical disk is also performed intermittently even during recording. In this way, even when writing to the optical disk is performed intermittently, the difference in rotation speed between when the disk writing is not being performed and when the disk writing is restarted is not caused. It is desired to control.

Accordingly, an object of the present invention is to control the rotation of an optical disk so that there is no difference between the rotation speed when the optical disk is not being read and the rotation speed when the reading of the optical disk is restarted. It is an object of the present invention to provide an optical disk reproducing apparatus capable of performing the above.

Another object of the present invention is to control the rotation of the optical disk so that there is no difference between the rotation speed when writing to the optical disk is not performed and the rotation speed when writing to the optical disk is restarted. To provide an optical disk recording device capable of performing such operations.

[0019]

According to a first aspect of the present invention, there is provided a disk reproducing apparatus which intermittently reads data from an optical disk, comprising: CLV control means for controlling rotation of the optical disk at a constant linear velocity; CAV control means for controlling the rotation of the optical disc at a constant angular velocity;
A switching means for switching between the CLV control means and the CAV control means; when reading the optical disk, the optical disk is controlled at a constant linear velocity by the CLV control means;
The optical disk is controlled at a constant angular velocity by the AV control means, and when the optical disk is switched from a state of being controlled at a constant linear velocity to a state of being controlled at a constant angular velocity, rotation speed information of the optical disk when the disk is being rotated at a constant linear velocity is taken in. In controlling the optical disk at a constant angular velocity, the rotational speed of the optical disk is controlled at a constant angular velocity by using the acquired rotational speed information when the optical disk is rotated at a constant linear velocity. It is an optical disk reproducing device.

According to a fourth aspect of the present invention, there is provided a disk recording apparatus which intermittently writes data to an optical disk, a CLV control means for controlling the rotation of the optical disk at a constant linear velocity, and the optical disk at a constant angular velocity. CAV control means for controlling rotation, CLV control means and C
Switching means for switching between the AV control means and the optical disk; when recording on the optical disk, the optical disk is controlled at a constant linear velocity by the CLV control means; when not recording on the optical disk, the optical disk is controlled at a constant angular velocity by the CAV control means. When controlling the optical disc at a constant angular velocity, when the optical disc is switched from a state in which the optical disc is controlled at a constant linear velocity to a state in which the optical disc is controlled at a constant angular velocity, the rotation speed information obtained when the optical disc was rotated at a constant linear velocity is taken in. An optical disk recording apparatus characterized in that the rotation speed of an optical disk is controlled at a constant angular velocity by using the acquired rotation speed information when the disk is rotated at a constant linear velocity.

With the above configuration, there is almost no speed difference between the rotation speed of the optical disk when the optical disk is controlled at a constant angular speed and the rotation speed when the reading of the optical disk is restarted, thereby reducing power consumption. Can be achieved.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a reproduction-only MD player to which the present invention is applied.

In FIG. 1, reference numeral 1 denotes an optical disk. The optical disc 1 has a diameter of 64 mm housed in a cartridge.
And what is called an MD. In the MD, compressed audio data is recorded at a constant linear velocity, and there are a type that can be recorded and reproduced and a type that is dedicated to reproduction. A recordable / reproducible MD is a magneto-optical disc, and a read-only MD is an optical disc on which data is recorded as a pit string.

The optical disk 1 is driven to rotate by a spindle motor 2. As the spindle motor 2, for example, a brushless motor is used. A spindle control signal is supplied to the spindle motor 2 via a driver 3.

The reading of the optical disk 1 is performed intermittently.
(Constant linear velocity), and when data is not being reproduced, it is rotated at CAV (constant angular velocity). In order to rotate the optical disc 1 at CLV, CLV
A servo circuit 5 is provided. Further, a CAV servo circuit 6 is provided to rotate the optical disc 1 at CAV. The CLV servo circuit 5 uses an AIDP (Address In)
Pregroove) output of demodulation circuit 18 or EFM (8-14)
Modulation) and ACIRC (Advanced Cross Interleave Re
The rotation of the optical disc 1 is controlled by the CLV based on the reproduced bit clock from the ed-Solomon Code) circuit 20. C
The AV servo circuit 6 controls the rotation of the optical disc 1 by CAV based on the FG signal output from the spindle motor 2.

The output of the CLV servo circuit 5 is supplied to a terminal 4A of the switch circuit 4. The output of the CAV servo circuit 6 is supplied to a terminal 4B of the switch circuit 4. The switch circuit 4 receives the CLV /
A CAV control signal is provided. The output of the switch circuit 4 is supplied to the spindle motor 2 via the driver 3.

An optical head 8 is provided for the optical disk 1. The optical head 8 has a laser diode for outputting laser light, an optical system such as a polarizing beam splitter and an objective lens, and a plurality of detectors for detecting light reflected from the disk. The optical head 8 has 2
An axis device is provided, and the objective lens in the optical head 8 can be displaced in the focus direction (direction of coming and coming from the disk) and the tracking direction (radial direction of the disk) by the two-axis device. The entire optical head 8 can be moved in the radial direction of the disk by a thread feed motor 9.

Laser light is emitted from a laser diode of the optical head 8, the laser light is reflected by the optical disk 1, and the reflected light is detected by a plurality of detectors of the optical head 8. The output of the laser light from the laser diode is detected by the laser controller 11, and the output of the laser beam is controlled by the laser controller 11.

The output of the optical head 8 is supplied to an RF amplifier 10. The RF amplifier 10 calculates the output of each detector of the optical head 5 to obtain a reproduced RF signal, a tracking error signal, and a focus error signal. Servo processing is performed by these error signals.

That is, the focus error signal obtained by the RF amplifier 10 is supplied to the focus servo circuit 12. A focus control signal is formed from the focus servo circuit 12 based on the focus error signal. This focus control signal is supplied to the biaxial device of the optical head 8 via the driver 13.

The tracking error signal obtained by the RF amplifier 10 is supplied to a tracking servo circuit 14. A tracking control signal is formed from the tracking servo circuit 14 based on the tracking error signal. This tracking control signal is the driver 1
5 is supplied to the biaxial device of the optical head 8.

The tracking error signal obtained by the RF amplifier 10 is supplied to a thread servo circuit 16. The thread control signal is formed from the thread servo circuit 16 based on the tracking error signal. This thread control signal is supplied to the thread feed motor 9 via the driver 17.

When a recordable magneto-optical disc is used as the optical disc 1, the absolute position information is wobble-recorded along the groove of the optical disc.
The output of the RF amplifier 10 is supplied to the ADIP demodulation circuit 18. The ADIP demodulation circuit 18 demodulates the address information recorded on the optical disk 1 by wobbling.

The reproduced RF signal from the RF amplifier 10 is E
It is supplied to the FM and ACIRC decoder 20. EFM
And the ACIRC decoder 20 performs EFM demodulation processing and error correction processing by ACIRC on the reproduced RF signal.

The output of the EFM and ACIRC decoder 20 is temporarily output to the RA under the control of the memory controller 21.
Written to M22. Reading data from optical disk 1 by optical head 8 and RAM from optical head 8
Transfer of reproduction data in the system up to 22 is 1.41M
It is performed at a bit rate of bit / s.

The data written in the RAM 22 is read out at the timing when the transfer of the reproduction data becomes 0.3 Mbit / s, and is supplied to the audio compression decoder 23. In the audio compression decoder 23, audio data is expanded by ATRAC.

Writing / reading of data to / from the RAM 22 is performed by the memory controller 21 by specifying an address under the control of a write pointer and a read pointer. As described above, the transfer rate of the reproduction data is 1.41.
Mbit / s, and the write pointer is 1.41 Mbi
It is incremented at the timing of t / s. On the other hand, the read transfer rate is 0.3 Mbit / s, and the read pointer is incremented at a timing of 0.3 Mbit / sec. Data is accumulated in the RAM 22 due to the difference between the write and read bit rates.

When a predetermined amount or more of data is accumulated in the RAM 22, the increment of the write pointer is stopped, and the operation of reading data from the optical disk 1 by the optical head 8 is also stopped. During this time, the read pointer is continuously incremented.

Only the read operation from the RAM 22 is continued, and when the amount of data stored in the RAM 23 becomes smaller than a predetermined amount at a certain time, the data read operation by the optical head 8 and the increment of the write pointer are restarted again.
The data is stored in the RAM 22 again.

The output of the audio compression decoder 23 is supplied to a D / A converter 24. The digital audio signal is converted into an analog audio signal by the D / A converter 24. This analog audio signal is output from the output terminal 25.

The overall operation is managed by the system controller 7. An input is provided to the system controller 7 from the input keys 26. The input keys 26 include, for example, a play key, a stop key, an AMS key, and a search key. The output of the system controller 7 is supplied to the display 27. Various settings are displayed on the display 27.

In the MD reproducing apparatus to which the present invention is applied, the reading of data from the optical disc 1 is performed intermittently. When reading data from the optical disk 1, the switch circuit 4 is set to the terminal 4A side,
The rotation of the optical disc 1 is controlled by the CLV. Optical disk 1
If the address is wobble-recorded, the ADI
The output of the P demodulation circuit 18 is supplied to the CLV servo circuit 5. When the address is not wobble-recorded on the optical disc 1, the reproduced bit clock is supplied to the CLV servo circuit 5. In the CLV servo circuit 5, ADIP
Using the output of the demodulation circuit 18 or the reproduced bit clock,
The optical disc 1 is controlled by the CLV.

The reproduced data from the optical disk 1 is demodulated and error-corrected by an EFM and ACIRC circuit 20, supplied to a RAM 22 via a memory controller 21, and stored in the memory 22. When the capacity of the RAM 22 becomes equal to or larger than a predetermined amount, reading of data from the optical disc 1 is interrupted, and the apparatus enters a sleep mode. In the sleep mode, the operation of the parts other than the memory controller 21, the RAM 22, the audio compression decoder 23, and the D / A converter 24 is stopped in order to reduce power consumption. At the same time, when entering the sleep mode, the switch circuit 4 is set to the terminal 4B side by the CAV / CLV control signal from the system controller 7.

Further, the CAV / CLV control signal is
It is supplied to the AV control circuit 6. The CAV servo circuit 6
FG immediately before switching from CLV control to CAV control
It has a register to capture the period. When the CAV / CLV control signal is supplied to the CAV servo circuit 6, the cycle of the FG signal immediately before switching from the CLV servo to the CAV servo is taken into this register. When the switch circuit 4 is set to the terminal 4B side, the rotation of the spindle motor 2 is controlled by CAV based on the FG cycle immediately before switching from CLV servo to CAV servo.

That is, as shown in FIG. 2, the CAV servo circuit 6 comprises an FG cycle measuring circuit 31 for measuring the cycle of the FG signal from the spindle motor 2 and a reference value register 32.
, A comparison circuit 33 and a low-pass filter 34. Further, a latch pulse generation circuit 35 is provided.
A V / CLV control signal is provided.

When the CAV / CLV control signal from the terminal 36 is switched to the CAV side, the switch circuit 4 is switched from the terminal 4A to the terminal 4B, and the latch pulse generating circuit 35 generates a latch pulse LP. Due to this latch pulse LP, the optical disc 1
The FG cycle immediately before being controlled by the LV is taken into the reference value register 32. That is, the speed information of the optical disk 1 immediately before the optical disk 1 is controlled by the CLV is detected from the output of the FG cycle measuring circuit 31 at this time. The output of the FG cycle measurement circuit 31 is taken into the reference value register 32.

The spindle motor 2 generates an FG signal according to the rotation speed of the spindle motor 2. This FG signal is supplied to the FG cycle measurement circuit 31. FG
The cycle of the FG signal is measured by the cycle measuring circuit 31. The rotation speed of the spindle motor 2 is detected from the cycle of the FG signal. The output of the FG cycle detection circuit 31 is supplied to the comparison circuit 33.

The output of the reference value register 32 is supplied to the comparison circuit 33. The reference value register 32 stores the cycle RFG of the FG signal immediately before the optical disc 1 is controlled by the CLV. In the comparison circuit 33, the cycle RFG of the FG signal immediately before the optical disc 1 is controlled by the CLV is compared with the current cycle of the FG signal of the spindle motor 2, and a speed error and a phase error are obtained. The output of the comparison circuit 33 is a low-pass filter 34,
The power is supplied to the spindle motor 2 via the switch circuit 4 and the driver 8.

In FIG. 1, in the sleep mode, the reading of data from the disk is interrupted and the RAM 22
Data reading from is continued. And RAM2
When the capacity of No. 2 becomes equal to or less than the predetermined value, reading of data from the optical disc 1 is restarted.

When data reading from the optical disk 1 is resumed, various servo circuits such as the focus servo circuit 12, the tracking servo circuit 14, the thread servo circuit 16, and the laser controller 11, which have been turned off during the sleep mode, , EFM and ACIRC decoder 20 are turned on. Then, the switch circuit 4 is set to the terminal 4A side by the CAV / CLV control signal from the system controller 7.

When the switch circuit 4 is set to the terminal 4A side, the optical disk 1 is rotated at CLV. Optical disk 1
Immediately before is controlled by the CLV, the optical disc 1
V is rotated. When controlling with CAV,
Since the rotation speed of the optical disk 1 was controlled by comparing the period RFG of the FG signal when the optical disk 1 was controlled by the CLV and the period of the FG signal of the spindle motor 2 until then, the rotation speed of the optical disk 1 was controlled. Immediately before
This is the line speed of the optical disk 1 when controlled by the CLV. Therefore, there is almost no difference between the rotational speed of the optical disk 1 when the optical disk 1 is controlled by the CAV in the sleep mode and the rotational speed when the reading of the optical disk is restarted. For this reason, a large amount of power is consumed when the optical disk 1 is controlled by the CAV in the sleep mode, and the optical disk 1 is controlled by the CLV to resume reading data from the optical disk 1. Can be prevented.

FIG. 3 shows another example of the present invention. In the above-described example, the MD player is a reproduction-only MD player. In this example, however, an MD recorder / player capable of recording / reproduction is used.

In FIG. 3, the optical disk 51 is an MD, on which compressed audio data is recorded at a constant linear velocity. The MD includes a recordable / reproducible type and a read-only type, and the recordable / reproducible MD is a magneto-optical disk. The optical disk 51 has a spindle motor 5
2 is driven to rotate. As the spindle motor 52, for example, a brushless motor is used. A spindle control signal is supplied to the spindle motor 52 via a driver 53.

The rotation of the optical disk 51 is controlled by CLV when writing or reading data, and is controlled by CAV when writing or reading data is not performed. Optical disk 51
A CLV servo circuit 55 is provided to rotate the CLV at CLV. Further, a CAV servo circuit 56 is provided to rotate the optical disc 1 at CAV.

The output of the CLV servo circuit 55 is supplied to a terminal 54A of the switch circuit 54. The output of the CAV servo circuit 56 is supplied to a terminal 54B of the switch circuit 54. The switch circuit 54 includes the system controller 5
7 supplies a CLV / CAV control signal. The output of the switch circuit 54 is supplied to the spindle motor 52 via the driver 53.

With respect to the optical disk 51, the optical head 58
Is provided. The optical head 58 has a laser diode for outputting laser light, an optical system such as a polarizing beam splitter and an objective lens, and a plurality of detectors for detecting light reflected from the disk. Optical head 5
8 is provided with a two-axis device, by which the objective lens in the optical head 58 can be displaced in the focus direction and the tracking direction.

The magnetic head 8 faces the optical head 58.
4 are provided. The magnetic head 84 applies a magnetic field modulated by data to the recordable / reproducible optical disk (magneto-optical disk) 51. Optical head 5
8 and the entire magnetic head 84, the thread motor 59
Thus, the disk can be moved in the radial direction.

Laser light is emitted from the laser diode of the optical head 58. The output of the laser light from the laser diode is detected by the laser controller 61, and the output of the laser beam is controlled by the laser controller 61. The power of the laser light from the laser diode is increased to increase the temperature of the optical disk 1 to the Curie temperature or higher at the time of writing, and reduced at the time of reading.

The output of the optical head 58 is supplied to the RF amplifier 60
Supplied to The output of each detector of the optical head 58 is arithmetically processed by the RF amplifier 60, so that the reproduction RF
A signal, a tracking error signal, and a focus error signal are obtained. Servo processing is performed by these error signals.

That is, the focus error signal obtained by the RF amplifier 60 is supplied to the focus servo circuit 62. A focus control signal is formed from the focus servo circuit 62 based on the focus error signal. This focus control signal is supplied to the biaxial device of the optical head 58 via the driver 63.

The tracking error signal obtained by the RF amplifier 60 is supplied to a tracking servo circuit 64. A tracking control signal is formed from the tracking servo circuit 64 based on the tracking error signal. This tracking control signal is transmitted to the driver 6
5 is supplied to the two-axis device of the optical head 58.

The tracking error signal obtained by the RF amplifier 60 is supplied to a thread servo circuit 66. From the thread servo circuit 66, a thread control signal is formed based on the tracking error signal. This thread control signal is supplied to the thread feed motor 59 via the driver 67.

The overall operation is managed by the system controller 57. The system controller 57 includes:
An input is provided from an input key 76. The input key 76
For example, record key, play key, stop key, AMS key,
It consists of a search key and the like. Also, the system controller 5
7 is supplied to the display 77. Various setting states are displayed on the display 77.

At the time of recording, an analog audio signal is supplied to the input terminal 81. This analog audio signal is supplied to the A / D converter 82. The analog audio signal is digitized by the A / D converter 82 with, for example, a sampling frequency of 44.1 kHz, a quantization bit number of 16 bits, and left and right two channels.

The output of the A / D converter 82 is supplied to an audio compression encoder / decoder 73. The audio compression encoder / decoder 73 compresses audio data by ATRAC. In ATRAC, the input audio data is divided into high-frequency, mid-frequency,
It is divided into three low frequency bands. Then, this audio data is cut out at 512 samples (a time window at a maximum of 11.6 msec) and converted into spectrum data by MDCT. This spectrum data is quantized after being normalized for each coding unit. As a result, the audio data is compressed to about 1/5.

The output of the audio compression encoder / decoder 73 is supplied to the RAM 72 under the control of the memory controller 71.
Is stored once. When a predetermined amount or more of data is stored in the RAM 72, the data is read from the RAM 72,
The output of the RAM 72 is supplied to the EFM and ACIRC encoder / decoder 70.

The EFM and ACIRC encoder / decoder 70 performs error correction encoding based on ACIRC, and further, EFM modulates the recording data. This EF
The outputs of M and ACIRC encoder / decoder 70 are:
The data is supplied to a magnetic head 84 via a driver 83.

At the time of reproduction, the reproduction R from the RF amplifier 60 is
The F signal is supplied to the EFM and ACIRC encoder / decoder 7.
0 is supplied. The EFM and ACIRC encoder / decoder 70 performs EFM demodulation processing and error correction processing by ACIRC on the reproduced RF signal.

The output of the EFM and ACIRC encoder / decoder 70 is temporarily written to the RAM 72 under the control of the memory controller 71. Since the transfer rate of reproduced data is 1.41 Mbit / s and the transfer rate of read is 0.3 Mbit / s, data is accumulated in the RAM 22 due to the difference between the bit rates of write and read. When a predetermined amount or more of data is stored in the RAM 72, reading of data from the optical disk 51 is interrupted, and only reading of data is performed. Then, when the amount of data stored in the RAM 72 becomes equal to or less than the predetermined amount, data reading from the optical disk 51 is started again.

The output of the RAM 72 is an audio compression encoder /
The data is supplied to the decoder 73. The audio compression encoder / decoder 73 expands the audio signal. The output of the audio compression encoder / decoder 73 is a D / A converter 7
4 is supplied. The digital audio signal is converted into an analog audio signal by the D / A converter 74. This analog audio signal is output from the output terminal 75.

At the time of recording, the recording data is temporarily stored in the RAM 72 until the data in the RAM 72 reaches a predetermined amount. During that time, no data is written to the optical disk 51. When the amount of data in the RAM 72 reaches a predetermined amount, data writing to the optical disk 51 is performed. In this manner, data recording on the optical disk 51 is performed intermittently.

At the time of reproduction, EFM and AC
The output of the IRC encoder / decoder 70 is
When the data is written to M72 and a predetermined amount or more of data is stored in RAM 72, reading of data from optical disk 51 is interrupted, and only reading of data is performed. Then, when the amount of data stored in the RAM 72 becomes equal to or less than the predetermined amount, data reading from the optical disk 51 is started again. In this way, the reading of data from the optical disk 51 is performed intermittently.

The sleep mode is set while data recording on the optical disk 51 is interrupted during recording, and while data reading from the optical disk 51 is interrupted during reproduction. In the sleep mode, the memory controller 7
1, RAM 72, audio compression encoder decoder 73, A
The operation of the parts other than the / D converter 82 and the D / A converter 24 is stopped. At the same time, the optical disk 51
While data is being recorded on the optical disk 51 and data is being read from the optical disk 51, the switch circuit 54 is set to the terminal 54A side, and the optical disk 51 is under CLV control. When entering the sleep mode, the switch circuit 54 is set to the terminal 54B side by the CAV / CLV control signal from the system controller 57, and CAV control is performed.

This CAV / CLV control signal is
It is supplied to the AV servo circuit 56. CAV servo circuit 5
Reference numeral 6 has a register for taking in the cycle of the FG signal immediately before switching from the CLV servo to the CAV servo. This CAV / CLV control signal is applied to the CAV servo circuit 5
6 is supplied to this register from the CLV servo.
The cycle of the FG signal immediately before switching to the AV servo is captured. When the switch circuit 54 is set to the terminal 54B side, the rotation of the spindle motor 52 is controlled by CAV based on the cycle of the FG signal immediately before switching from the CLV servo to the CAV servo.

When the writing of data to the optical disk 1 or the reading of data to the disk 1 is resumed,
Various servo circuits such as the focus servo circuit 62, the tracking servo circuit 64, the thread servo circuit 66, and the laser controller 61, which are turned off during the sleep mode, and reproduction signal processing circuits such as the EFM and ACIRC encoder / decoder 70 are provided. Turned on. Then, the switch circuit 54 is set to the terminal 54A side by the CAV / CLV control signal from the system controller 57.

When the switch circuit 54 is set to the terminal 54A side, the optical disk 51 is rotated by CLV. When the optical disk 51 is rotated at the CLV, the rotation speed of the optical disk 51 is the line speed of the optical disk 51 when the optical disk 51 was controlled by the CLV immediately before. Therefore,
When the rotation control of the optical disk 51 is switched from CAV to CLV and the rotation of the optical disk 51 is restarted, the rotation speed of the optical disk 51 is set at that position.
It becomes almost the same as the rotation speed of the optical disk 51 when controlled by V.

Although the present invention has been described with respect to an example in which the present invention is applied to a reproduction-only MD player and a recordable / reproducible MD player, the present invention includes, for example, a buffer memory and temporarily reproduces reproduction data from an optical disk. The present invention can be similarly applied to a CD player in which data is stored in a buffer memory.

[0078]

According to the present invention, when reading data from an optical disk intermittently, when reading the optical disk, the optical disk is controlled at a constant linear velocity. When reading the optical disk is interrupted, the optical disk is controlled at an angular velocity. It has been switched to control at a constant. And
When switching from a state in which the optical disk is controlled at a constant linear velocity to a state in which the optical disk is controlled at a constant angular velocity, the rotation speed information obtained when the optical disk is rotated at a constant linear velocity is taken in. The rotational speed of the optical disk is controlled to be constant at the angular velocity using the acquired rotational speed information.

When intermittently writing data from an optical disk, the optical disk is controlled at a constant linear velocity when writing to the optical disk, and the optical disk is controlled at a constant angular velocity when writing to the optical disk is interrupted. Switching. When switching from a state in which the optical disk is controlled at a constant linear velocity to a state in which the optical disk is controlled at a constant angular velocity, the rotation speed information obtained when the disk is rotated at a constant linear velocity is taken in. The rotational speed of the optical disk is controlled to be constant at the angular velocity by using the acquired rotational speed information.

As a result, there is almost no speed difference between the rotation speed of the optical disk when the optical disk 1 is controlled at a constant angular velocity and the rotation speed when the reading of the optical disk is restarted, and power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of an example of a disk reproducing apparatus to which the present invention has been applied.

FIG. 2 is a block diagram used to describe an example of a CAV control circuit in a disk reproducing apparatus to which the present invention has been applied.

FIG. 3 is a block diagram showing an example of a disc recording / reproducing apparatus to which the present invention is applied.

FIG. 4 is a block diagram illustrating an example of a conventional servo circuit.

[Explanation of symbols]

1 ... optical disk, 4 ... switch circuit, 5 ...
CLV servo circuit, 6 ... CAV servo circuit, 37
..FG cycle measuring circuit, 32 ... reference value register, 3
3 ... Comparison circuit

Claims (6)

[Claims] 1. A disk reproducing apparatus which intermittently reads data from an optical disk, comprising: CLV control means for controlling the rotation of the optical disk at a constant linear velocity; and CAV control for controlling the rotation of the optical disk at a constant angular velocity. Means, and switching means for switching between the CLV control means and the CAV control means.
When the optical disk is controlled at a constant linear velocity by the V control means and the optical disk is not read,
The CAV control means controls the optical disk at a constant angular velocity, and switches the optical disk from a state of constant linear velocity control to a state of constant angular velocity control when the optical disk is rotated at the constant linear velocity. Incorporating rotation speed information, and controlling the optical disk at a constant angular velocity, the rotation speed of the optical disk is controlled at a constant angular velocity by using the captured rotation speed information when the disk is rotated at a constant linear velocity. An optical disk reproducing apparatus characterized in that the optical disk reproducing apparatus is configured to perform the above operation. A buffer memory for storing reproduction data from the optical disk; reading the optical disk until the capacity of the buffer memory is equal to or more than a predetermined amount; 2. The optical disk reproducing apparatus according to claim 1, wherein reading of said optical disk is interrupted. 3. The CAV control means has a storage means for taking in rotation speed information, and rotates the optical disk at a constant linear velocity when switching from a state of controlling the optical disk at a constant linear velocity to a state of controlling at a constant angular velocity. The rotation speed information at the time of moving is taken into the storage means.
An optical disk reproducing apparatus according to claim 1. 4. A disk recording apparatus which intermittently writes data to an optical disk, wherein: CLV control means for controlling the rotation of the optical disk at a constant linear velocity; and CAV control for controlling the rotation of the optical disk at a constant angular velocity. Means, and switching means for switching between the CLV control means and the CAV control means. When performing recording on the optical disc, the CLV control means controls the optical disc at a constant linear velocity to perform recording on the optical disc. If not, the above CAV
The control means controls the optical disk at a constant angular velocity and fetches rotational speed information when the optical disk was rotated at a constant linear velocity when switching from a state where the optical disk is controlled at a constant linear velocity to a state where it is controlled at a constant angular velocity. When controlling the optical disk at a constant angular velocity, the rotational speed of the optical disk is controlled at a constant angular velocity using the acquired rotational speed information when the optical disk is rotated at a constant linear velocity. An optical disk recording device characterized by the above-mentioned. 5. A buffer memory for storing data to be recorded on the optical disk, wherein if the capacity of the buffer memory is equal to or more than a predetermined amount, data is written to the optical disk, and the capacity of the buffer memory becomes equal to or less than a predetermined amount. 5. The optical disk recording device according to claim 4, wherein the writing to the optical disk is interrupted when the recording is completed. 6. The CAV control means has storage means for taking in rotation speed information, and rotates the optical disk at a constant linear velocity when switching from a state in which the optical disk is controlled at a constant linear velocity to a state in which the optical disk is controlled at a constant angular velocity. 5. The rotation speed information when the rotation is performed is taken into the storage means.
An optical disc recording apparatus according to claim 1.