JPH09251703A - Disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable re-reading without interrupting an output and to obtain an accurate audio output by increasing the speed of data transfer in accordance with the number of pickups and buffering data at the time of reproducing a CD-DA disk. SOLUTION: Signals from pickups 3, 4 are inputted to CD signal processing circuits 13, 14 through RF amplifiers 5, 6 respectively, synchronization detection, EFM demodulation, sub-code separation, Q code demodulation, error correction, and time base compensation processing are performed. Then, bit clocks from clock reproducing circuits 10, 11 and a reference clock of a reference oscillation circuit 12 are used in this processing, and synchronized CD-ROM data is stored in a buffer RAM 20. Also, it is discriminated whether it is CD-DSA or CD-ROM, and it is inputted to the buffer RAM 20, CD-ROM signal processing circuits 18, 19. Thereby, data processing is performed with speed of a disk player corresponding to a CD system, data can be read simultaneously from pickups 3, 4.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a CD and a CD-RO.
The present invention relates to a disc reproducing apparatus using an optical disc such as M as a recording medium, and particularly to signal processing for reading and outputting recorded information.

[0002]

2. Description of the Related Art Optical discs have become popular as a means for transmitting multimedia information including video and audio, and are used for music C.
In addition to CD-based media such as D, CD-ROM, and video CD, high-density, large-capacity DVD has been developed.

It is well known that a disc reproducing apparatus such as a CD-ROM disc is used as a storage medium of a computer.

In recent years, along with the increase in the processing speed of computers and the increase in processed data, the data transfer rate with the disk reproducing device has been increased.

Conventionally, as a technique for increasing the data transfer rate, an information recording disk has twice the rated speed and 4
The data transfer rate has been increased by rotating the data at a high speed such as twice or six times and reading the data at a high speed.

However, in such a disc reproducing apparatus, there is a drawback in that it is necessary to develop a pickup and a motor corresponding to high-speed rotation and high-speed data processing, and a signal processing circuit for error correction.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and reproduces a disk without using a pickup, a motor and an error correction signal processing circuit for high-speed rotation and high-speed data processing. The technical problem is to increase the data transfer rate of the device.

[0008]

The present invention has the following features to solve the above problems.

A driving mechanism corresponding to each of the plurality of pickups, a pickup driving circuit and a signal processing circuit, a storage means for storing an output signal of the signal processing circuit, and an output circuit for outputting data from the storage means are provided. The signals read from the information recording disk by the plurality of pickups are processed by the signal processing circuits corresponding to the pickups, stored in the storage means, and the stored information is output from the data output circuit.

Further, the pickups are arranged so that the signals read by the pickups simultaneously in a unit time correspond to the continuous areas recorded on the information recording disk, and the signals simultaneously read by the respective pickups are processed by the signal processing circuit. The data is stored in each area of the storage means corresponding to the continuous area recorded on the information recording disk, and the data of the storage means is sequentially output by the data output circuit.

Further, in the next unit time, each pickup is arranged from a continuous area of the continuous area of the information recording disk read in the previous unit time, and reading and storage in the storage means are repeated.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a disc reproducing apparatus of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram of a disc reproducing apparatus according to the present invention.

In the figure, (1) is an information recording disk such as a CD-DA (audio CD) and a CD-ROM.

(2) is a disc motor, and the information recording disc (1) is rotated by a spindle motor.

Reference numerals (3) and (4) are pickups for reading signals from the information recording disk (1) with a laser beam.

Although a plurality of pickups are used in this apparatus, a case where two pickups are used will be described here.

The pickup (3) is located on the inner circumference side of the pickup (4) and can be independently driven.

RF amplifiers (5) and (6) are provided for the RF signals read by the pickups (3) and (4), respectively.
Amplify and shape the waveform.

A motor servo circuit (7) controls the rotation of the disk motor (2).

Pickup servo circuits (8) and (9) perform focusing control, tracking control and feed control for the pickups (3) and (4).

Clock recovery circuits (10) and (11) reproduce a bit clock synchronized with the bits of the digital signal from the digital signals output from the RF amplifiers (5) and (6) by a PLL circuit. .

Reference numeral (12) is a reference oscillation circuit, which generates a reference clock by a crystal oscillator.

CD signal processing circuits (13) and (14) detect a frame synchronization signal from the digital signals from the RF amplifiers (5) and (6), EFM demodulation, subcode signal separation, and Q code demodulation. Perform error correction and time base correction.

RAMs (15) and (16) are RAMs, and
It is used to perform error correction and time base correction by the signal processing circuits (13) and (14).

(17) is a system control microcomputer,
Controls the operation of the entire hardware.

Reference numerals (18) and (19) denote CD-ROM signal processing circuits, which perform error correction unique to the CD-ROM on the data from the CD signal processing circuits (13) and (14).

A buffer RAM (20) stores data from the CD signal processing circuits (13) and (14) or the CD-ROM signal processing circuits (18) and (19).

(21) is a D / A converter, which is a CD
-Convert DA data from a digital signal to an analog signal and output the analog signal.

(22) is a host interface,
Communication control with external host computer and buffer R
The data stored in the AM 13 is sent to the host computer.

FIG. 2 shows the contents of the buffer RAM (20).

The CD-ROM data includes continuous areas (23), (24), (25), (2) on the buffer RAM.
6), the respective capacities and the data to be stored are managed by the system control microcomputer (17).

FIG. 3 shows an information recording disk (1) for explaining the data reading operation.

Here, (27), (28), (29),
(30) indicates an area read by the pickup per unit time, and is (31), (32), (33), (34).
Indicates the head position of each area, and each position and capacity are managed by the system control microcomputer (17).

The operation of the apparatus constructed as described above will be described below.

First, the operation of the motor servo circuit will be described.

In the motor servo circuit (7), the digital signal input from the pickup (3) through the RF amplifier (5) and the bit clock and reference signal oscillation circuit reproduced by the clock reproduction circuit (10) are supplied. The reference clock from (12) is input.

The motor servo circuit (7) detects the pulse width of the shortest pulse in the digital signal and controls the speed of the disk motor (2) so that the pulse width becomes a predetermined width.

In this way, the disc motor (2) is rotationally controlled, and the information recording disc (1) is rotationally controlled at a constant linear velocity.

Next, the operation of signal processing will be described.

The signal read from the pickup (3) is passed through the RF amplifier (5) to the CD signal processing circuit (1
Input to 3).

In the CD signal processing circuit (13), synchronization detection, EFM demodulation, subcode separation, Q code demodulation, error correction and time base correction are performed, and the information recording disk (1) is a CD-DA or CD. -The type of ROM is determined, and if it is CD-DA, it is stored in the buffer RAM (20) as CD-DA data, and if it is CD-ROM, it is CD-
Data is output to the ROM signal processing (18). here,
The type of the information recording medium (1) is determined by the identification code.

The synchronization detection, EFM demodulation, sub-code separation and Q-code demodulation are performed by using the bit clock from the clock recovery circuit (10) as an operation clock, and the error correction and time axis correction are performed by the reference oscillator circuit. (1
The reference clock from 2) is used as an operation clock, and thereby data processing is performed at the speed of a disc player compatible with a normal CD system.

In the CD-ROM signal processing circuit (18),
The data from the CD signal processing circuit (13) is used as a reference clock from the reference oscillation circuit (12) as an operating clock.
-Reference oscillation circuit (12) that performs error correction unique to ROM
It operates so as to store the CD-ROM data synchronized with the reference clock from the buffer RAM (20).

Similarly, the signal read from the pickup (4) is input to the CD signal processing circuit (14) through the RF amplifier (6), and the CD signal processing circuit (14) detects synchronization and EFM demodulation. Subcode separation and Q
The information recording disc (1) is a CD-DA or a CD-RO after being subjected to code demodulation, error correction and time base correction.
The type of M is judged, and if it is CD-DA, it is stored in the buffer RAM (20) as CD-DA data, and CD-R
If it is OM, data is output to the CD-ROM signal processing (19).

In the processing of the synchronization detection, EFM demodulation, sub-code separation, Q-code demodulation, error correction and time base correction, the bit clock from the clock recovery circuit (11) is used as an operation clock.

As a result, data processing is performed at a speed higher than the speed of the normal CD system compatible disc player from the pickup (4) located on the outer periphery of the pickup (3).

In the CD-ROM signal processing circuit (19),
The data from the CD signal processing circuit (14) performs error correction unique to the CD-ROM using the bit clock from the clock recovery circuit (11) as an operation clock, and the CD-synchronized with the bit clock from the clock recovery circuit (11). RO
It operates to store M data in the buffer RAM (20).

By operating in this way, it is possible to read data from the information recording disk from the pickups (3) and (4) at the same time.

Next, the operation of the system control microcomputer (17) and two systems of CD-DA data from the CD signal processing circuits (13) and (14) or the CD-ROM signal processing circuits (18) and (). 2) CD-from 19)
A method for storing the ROM data in the buffer RAM (20) will be described.

The system control microcomputer (17) arranges the pickup (3) at the position (31) of the information recording disk (1) corresponding to the data reading position designated by the host through the host interface (22), and at the same time, the system is controlled. The pickup (4) is arranged at the position (32) of the information recording disk (1) which is continuous with the data amount (27) which can be read by the pickup (3) in the unit time determined by the control microcomputer (17).

The system control microcomputer (17)
Causes the pickups (3) and (4) to start reading at the same time so that the data in the areas (27) and (28) is the CD-DA data from the CD signal processing circuits (13) and (14), or the CD. -CD-ROM data from the ROM signal processing circuits (18) and (19) are simultaneously output.

Therefore, the system control microcomputer (17)
As shown in FIG. 2, first, the data of the area (23) of the buffer RAM that stores the data of the area (27) read from the pickup (3) and the data of the area (28) read from the pickup (4) per unit time. Area (24) of the buffer RAM for storing the CD-RAM from the CD signal processing circuit (13) is allocated continuously to the area (23).
The DA data or the CD-ROM data from the CD-ROM signal processing circuit (18) is stored in the area (23), and the CD-DA data or the CD-R from the CD signal processing circuit (14) is stored.
The CD-ROM data from the OM signal processing circuit (19) is stored in the area (24).

By operating in this way, the areas (27) and (28) following the position (31) designated by the host of the information recording disk (1) by the pickups (3) and (4) per unit time. Data in the area (23)
And (24).

Next, the system control microcomputer (17)
The pickup (3) is arranged at the position (34) of the information recording disc (1) continuous to the area (28), and the information recording continuous to the data amount (43) which can be read by the pickup (3) in the unit time. The pickup (4) is placed at the position (33) of the disc (1).

Then, as described above, the data in the areas (29) and (30) of the information recording medium (1) is stored in the area (2).
5) and (26) are stored.

The CD-DA data or CD-ROM data thus stored in the buffer RAM (20) is
If it is CD-DA data, it is output as audio from the D / A converter (21), and if it is CD-ROM data, it operates to transfer the data to the host through the host interface (22).

By continuously performing the above operation, 1
About twice as much data is read out from the information recording disk (1) per unit time as compared to when using one pickup,
Data can be transferred to the host via the host interface (22).

In the above embodiment, when the system control microcomputer (17) determines that the information recording disk (1) is a CD-DA, data is read from the two pickups (3) and (4) and buffered. , CD-D
When it is judged as A, only one pickup (3) and its related circuit are driven as usual, the data is read out only from the pickup (4), and the CD-DA data from the CD signal processing circuit (13) is transferred to D It is also possible to output audio through the / A converter (21).

[0060]

As described above, according to the present invention, it is possible to realize a high data transfer rate according to the number of pickups at a rotational speed at which a signal processing circuit such as a pickup, a motor and an error correction can operate. You can Also, CD-D
Since the data can be buffered when the A disc is reproduced, the audio output can be re-read without interruption when a reading error occurs, and an accurate audio output can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram of a disk reproducing apparatus according to the present invention.

FIG. 2 is a configuration diagram of a buffer RAM of the disc reproducing apparatus of the present invention.

FIG. 3 is a schematic diagram of an information recording disc.

[Explanation of symbols]

 1. Information recording disc 2. Disk motor 3. Pickup 4. Pickup 5,6. RF amplifier 7. Motor servo circuit 8, 9. Pickup servo circuit 10, 11. Clock recovery circuit 12. Reference oscillation circuit 13, 14. CD signal processing circuit 15, 16. RAM 17. System control microcomputer 18, 19. CD-ROM signal processing circuit 20. Buffer RAM 21. D / A converter 22. Host interface 23-26. RAM area 27-30. Pickup reading area 31 to 34. Area start position

Claims (5)

[Claims] 1. A plurality of pickups for reading information recorded on an information recording disk, a drive mechanism, a pickup drive circuit and a signal processing circuit corresponding to each of the plurality of pickups, and an output signal of the signal processing circuit. Storage means and an output circuit for outputting data from the storage means. The signals read from the information recording disc by the plurality of pickups are processed by the signal processing circuits corresponding to the pickups, respectively, and the storage is performed. A disk reproducing apparatus, characterized in that the information stored in the storage means and the information stored in the storage means is output from the data output circuit. 2. The pickups are arranged so that signals picked up by the pickups simultaneously in a unit time correspond to continuous areas recorded on an information recording disk, and signals read simultaneously by the pickups are read by the signal processing circuit. 2. The processed data is stored in each area of the storage means corresponding to a continuous area recorded on the information recording disk, and the data of the storage means is sequentially output by the data output circuit. Disc playback device. 3. In a second unit time following the unit time (first unit time), each pickup is arranged and read from an area continuous to a continuous area of the information recording disk read in the first unit time. 3. The disk reproducing apparatus according to claim 2, wherein the storage in the storage means is repeated. 4. A disc reproducing apparatus according to claim 1, further comprising a discriminating means for discriminating an information recording disc, wherein said disc reproducing device performs said operation if the disc is an information recording disc of a predetermined type. 5. A discriminating means for discriminating an information recording disc, wherein the above operation is carried out in the case of a first type information recording disc, and only one pickup is operated in the case of a second type information recording disc. 4. The method according to claim 1, wherein
The disc reproducing apparatus described.