KR19980068748A - Optical disc recorder - Google Patents

Abstract

In the optical disc recording and reproducing apparatus, in particular, in the case of a single layer structure, data and a control clock indicating a change in the number of revolutions of the disc at the time of recording are recorded on the disc together. After recording the control clock, two optical pickups are used to scan one data and the other to scan the control clock, eliminating the need for a hard-to-control PLL as the speed increases during playback, eliminating any errors that occur in the PLL. Data errors are reduced, and the clock is read directly from the disk, making speed control easy, which saves money by eliminating the need for expensive spindle motors.

Description

Optical disc recorder

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc recording and reproducing apparatus, and more particularly, to an optical disc recording and reproducing apparatus for recording not only program data but also control data on a disc and simultaneously reading program data and control data using two pickups during disc reproduction. It is about.

Disc media players, such as compact discs (CDs) and digital versatile discs (DVDs), are used as pickups to record and read data.

Fig. 1 is a simple block diagram of such a conventional optical disc recording and reproducing apparatus, which reads from an optical disc 10, an optical pickup 11 for recording and reproducing data on the optical disc 10, and an optical pickup 11; Phase Locked Loop (PLL) 12 generating a clock by using a high frequency (RF) signal, and data read from the optical pickup 11 in synchronization with a clock generated by the PLL 12. And a data reproducing unit 13 for reproducing.

FIG. 1 configured as described above records data on the disc 10 via the optical pickup 11.

During data reproduction, the PLL 12 decodes the recording data read from the disc 10 through the optical pickup 11 as shown in a of FIG. 2 to generate a clock signal from the recorded data as shown in FIG.

The data reproducing unit 13 controls the disk rotation by the clock generated by the PLL 12 to reproduce the recorded data.

In the case of CD, data is 3 clocks (3T) or more and 11 clocks (11T) or less, and in the case of DVD, 3 clocks (3T) or more and 14 clocks (14T) or less.

In other words, the current speed is known and a method of reproducing the clock corresponding to the data by reading data from the disc is adopted.

At this time, since the disk has to have a constant linear velocity, the disk is rotated in a constant linear velocity (CLV) method.

However, in the conventional optical disc recording / reproducing apparatus, although CLV may be controlled roughly in the line where error of about 50% is allowed due to the improvement of the PLL technology, the CLV becomes more fine as the disc reproduction speed increases. Since it is necessary to control, the PLL is burdened, and a lot of errors occur in the PLL.

Therefore, there is a problem that the reproduction data is shaken, making it difficult to restore the correct data.

In addition, as the speed of the disk increases, it is difficult to control the disk at a constant linear speed, thereby requiring an expensive spindle motor.

Further, in order to generate a clock with the write data, an EFM (Eight to Fourteen Modulation) modulation that converts 8-bit symbols into 14-bit code values is required for data writing, thus requiring additional circuitry and memory.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to record not only data but also a control clock on a disc, and to reproduce the program data and the control clock by using two pickups during disc playback. To provide an optical disk recording and reproducing apparatus that does not require a PLL.

Another object of the present invention is to record data on one layer of the disc, and to record the control clock on the other layer, so that the program data and the control clock can be read at the same time by using two pickups when the disc is reproduced. A recording and reproducing apparatus is provided.

Features of the optical disc recording and reproducing apparatus according to the present invention for achieving the above object include an optical disc, a control optical pickup for recording and reading a control clock on the optical disc, and recording program data on the optical disc. And a data reproducing section for reproducing data read from the data optical pickup in synchronization with the control clock read out from the control optical pickup.

1 is a block diagram of a conventional optical disc recording / reproducing apparatus

2A and 2B are timing diagrams of operations of each part of FIG. 1.

3 is a block diagram of an optical disc recording and reproducing apparatus according to the present invention;

4A and 4B are timing diagrams of operations of each part of FIG. 3.

Explanation of symbols for the main parts of the drawings

30 optical disc 31 optical pickup for control

32: optical pickup for data 33: data reproducing unit

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a simple block diagram of an optical disc recording and reproducing apparatus according to the present invention.

3, an optical disc 30, a control optical pickup 31 for recording and reading a control clock on the optical disc 30, and a data for recording and reading program data on the optical disc 30. An optical pickup 32 and a data reproducing section 33 which reproduces data read out from the data optical pickup 32 in synchronization with the control clock read out from the control optical pickup 31.

The optical disk 30 may have a single layer structure or a two layer structure.

According to the present invention configured as described above, when the disk 30 has a single layer structure, data and a control clock indicating a change in the number of rotations of the disk at the time of recording are recorded on the disk 30 together. Data is recorded, and a control clock indicating a change in the number of revolutions of the disc at the time of recording is recorded.

Therefore, in the two-layer disk 30, if data is recorded in one layer and the control clock is recorded in the other layer, the control optical pickup 31 scans the layer in which the control clock is recorded during reproduction, as shown in FIG. The control clock is output to the data reproducing section 33.

In addition, the data optical pickup 32 scans the layer on which the data is recorded and outputs the recorded data to the data reproducing section 33.

The data reproducing section 33 controls the disk rotation by the clock read out from the control optical pickup 31 to reproduce the recorded data from the data optical pickup 32 as shown in FIG.

On the other hand, even when the disc structure is a single layer, the control optical pickup 31 reads only the control clock, and the data optical pickup 32 reads only the data and outputs it to the data reproducing section 33. FIG.

At this time, the rotation of the disk may be controlled by CLV, or may be controlled by Constant Angular Velocity (CAV).

In addition, since the control clock is recorded on the disc during recording and the clock recorded on the disc is read during reproduction, the rotation of the disc is controlled so that the clock does not need to be generated from the recording data during reproduction, thereby eliminating the need for EFM modulation during recording.

This reduces the disk capacity by writing the control clock to disk, but eliminates the need for EFM modulation, which converts 8-bit to 14-bit and writes to disk, thus eventually reducing disk capacity.

In addition, the elimination of EFM modulation eliminates the circuitry and memory required for EFM modulation, simplifying circuit configuration and reducing costs.

As described above, according to the optical disc recording / reproducing apparatus according to the present invention, in the case of a single layer structure, data and a control clock indicating a change in the number of rotations of the disc at the time of recording are recorded together on the disc. Record the control clock on the other side, and then use two optical pickups to scan one data and the other to scan the control clock, eliminating the need for a difficult PLL as playback speed increases. Since there is no error occurring, the error of the reproduction data is reduced, and the clock is read directly from the disk, so the speed control is easy, and even if the speed increases, the expensive spindle motor is not required, thereby reducing the cost.

In addition, since the control clock is recorded on the disk during recording and the clock recorded on the disk is read during playback, the rotation of the disk is controlled, thereby eliminating the need to generate a clock from the recording data, thus eliminating the need for EFM modulation. The circuit configuration is simplified and the cost is reduced.

Claims (3)

With optical disc, A control optical pickup for recording and reading a control clock on the optical disk; An optical pickup for data which records and reads program data on the optical disk; And a data reproducing unit for reproducing data read from the data optical pickup in synchronization with the control clock read out from the control optical pickup. The optical disc recording and reproducing apparatus according to claim 1, wherein the optical disc has a single layer structure, and a control clock and program data are recorded together. The optical disc recording and reproducing apparatus according to claim 1, wherein the optical disc has a two-layer structure in which a control clock is recorded in one layer and program data is recorded in another layer.