JPH08212556A - Disk shaped recording medium recording method - Google Patents

Abstract

PURPOSE: To obtain a recording method for a disk-shaped recording medium capable of reproducing synchronizing signal stably. CONSTITUTION: At the time of recording a synchronizing signal having a modulation system different from a data signal in a snaked track, the synchronizing signal is recorded so that the distances of the synchronizing signal on a disk shaped recording medium 13 become almost equal intervals and the recording bandwidth of the synchronizing signal becomes narrower than the recording bandwidth of the data signal. Then, the rotational speed of a disk driving motor 12 is controlled so that the cycle of the synchronizing signal to be detected becomes constant by detecting the synchronizing signal from the disk shaped recording medium 13 and comparing the output of the detected synchronizing signal with the output of a reference oscillator 11 in a control device 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc-shaped recording medium recording method.

[0002]

2. Description of the Related Art Recently, a system has been proposed in which an audio signal converted into a PCM signal on a disk-shaped recording medium is recorded and reproduced as a binary signal. In this case, the sync signal is recorded, for example, in the form of Barker code or the like, and the sync signal is detected by a constant digital signal pattern.

On the other hand, in order to lengthen the recording time of a disk-shaped recording medium (hereinafter referred to as a disk), the number of rotations of the disk is set small at the outer peripheral portion and large at the inner peripheral portion to keep the recording density constant. It is also proposed to lengthen the recording time, CLV method (Constant Linear Velocity)
is called.

[0004]

In the case of such a CLV system, it is necessary to detect the synchronizing signal and control the number of rotations of the recording medium so that the cycle becomes constant. For that purpose, the recording is performed. It is necessary to reproduce the reproduced digital signal and stably detect the sync signal, and in the case of Barker code etc., the Barker code can be detected stably unless the disk rotation speed is controlled to the normal rotation speed. Have difficulty.

[0005] For this reason, it has been conventionally difficult to reproduce the digital signal to obtain a stable audio signal. An object of the present invention is to provide a disc-shaped recording medium recording method capable of stably reproducing a synchronization signal.

[0006]

According to the first aspect of the present invention, when a synchronization signal of a modulation method different from a data signal is recorded on a meandering track, the distance of the synchronization signal on the disk is reduced. The recording band of the synchronization signal is narrower than the recording band of the data signal at substantially equal intervals.

According to a second aspect of the present invention, in the recording method of a disk-shaped recording medium, the modulation method of the synchronization signal portion is an FM signal method modulated by a predetermined signal, and the band of the FM signal is narrower than the band of the data signal portion. It is characterized by recording.

According to a third aspect of the present invention, there is provided a recording / reproducing method for a disc-shaped recording medium, wherein when a synchronizing signal of a modulation method different from that of a data signal is recorded on a meandering track, the synchronizing signals have a substantially equal distance on the disc. The recording band of the synchronizing signal is recorded narrower than the recording band of the data signal, the synchronizing signal is detected from the disc-shaped recording medium, and the output of the detected synchronizing signal and the output of the reference oscillator are compared and detected. The rotation speed of the disk is controlled so that the cycle of the synchronization signal is constant.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a recording method of a disk-shaped recording medium according to the present invention will be described based on specific embodiments.

FIG. 1 shows a main configuration of a recording / reproducing apparatus for recording / reproducing an audio signal. The PCM modulator 1 outputs an audio signal (I) supplied to an input terminal (A) for recording.
Is converted into a PCM-converted digital signal (II), and a PCM-converted digital signal (II) and a synchronization signal (III) indicating a boundary between the PCM-converted digital signal (II) are provided on the output (c) side. It is output in the format shown in FIG. A signal representing the period of the synchronizing signal (III) is generated on the output (b) side.

The modulator 2 modulates the output (c) signal of the PCM modulator 1 and is assumed to be, for example, an MFM modulator. The synchronization signal modulator 3 outputs the synchronization signal (I
For example, if an FM modulator is used, the pilot signal d output from the pilot signal oscillator 5 is changed by the burst signal e gated through the gate circuit 4 by the output (b) signal. FM modulation is performed.

FIG. 2A shows this waveform.
Is the P separated by the synchronization signal (III) as described above.
FIG. 2 (b) is a CM signal in which the portion of the synchronization signal (III) is enlarged. Only the synchronizing signal portion in FIG. 2B is FM-modulated with the burst signal e as shown by the arrow (d).

The MFM-modulated signal is well known.
The minimum cycle is "T_O If you say "T _O "1.5 T_O "
“2T_O It consists of three types of pulse
And the FM-modulated signal of the synchronization signal (III) is
If the cycle is "T_O If you have to choose not to be shorter than
In this embodiment, the synchronization signal pulse is "1.5 T
_O ”, The burst signal e
"1.5 T_O Are modulated as carriers.

At the time of recording, the disk-shaped recording medium 13 is driven at a constant relative speed, and the output signal of the synchronous signal modulator 3 is recorded. At the time of reproduction, the signal reproduced by a signal reproducing device (not shown) has a waveform. Through the shaper 6, the FM demodulator 7 reproduces the burst signal shown in FIG. This is extracted by a bandpass filter 8 and converted into a synchronization signal pulse by a waveform shaper 9.

The bandpass filter 8 has an appropriate band (0.5 f to 1.5 f) depending on the rotation speed control range of the disk-shaped recording medium 13, for example, centering on the frequency of the pilot signal d.
To be chosen.

The output (reproduction synchronization signal) of the waveform shaper 9 is compared with the output of the reference oscillator 11 by the control device 10, and the disk-shaped recording medium 13 is rotated so that the reproduction synchronization signal becomes equal to the output of the reference oscillator 11. Disk drive motor 12 to drive
To control the rotation.

In the above embodiment, FFM modulation signal
Although the explanation has been made by adding the M-modulation synchronizing signal, the same applies to combinations of other modulation methods. Of course, it is preferable that the modulation method of the synchronization signal portion has a large jitter margin and is strong against fluctuations in the level of the reproduced signal, and the FSK method and the phase modulation method are also excellent.

Further, in the above embodiment, all the synchronization signals are FM-modulated. However, the modulation method may be partially changed and the remaining synchronization signal portions may use the conventional Barker code or the like. Further, when recording a signal on a disk, a signal reproducing apparatus having a so-called track wobbling type tracking servo for meandering the recording track is used.
It has been confirmed that when the disk-shaped recording medium of the present invention is used together with the LV system, the reproduction of the recording / reproducing apparatus operates stably.

In the above embodiment, the synchronization signal detecting means for detecting the synchronization signal from the disk-shaped recording medium is
It is composed of a waveform shaper 6, an FM demodulator 7, a bandpass filter 8 and a waveform shaper 9.

[0020]

As described above, according to the disk-shaped recording medium recording method of the present invention, it is possible to stably and accurately reproduce the sync signal, and in the conventional method using the Barker code or the like, it is caused by a disk defect. Although it often caused malfunctions due to dropout, it is confirmed by experiments that this point can be remarkably improved.

Further, when detecting the synchronization signal from the disk-shaped recording medium, since the band of the synchronization signal is narrower than the band of the data signal, the synchronization signal can be separated using a narrow band filter, and the detection of the synchronization signal can be stabilized.

Since the track wobbling and the CLV are very dependent on the stability of the detection of the synchronization signal, a great effect can be obtained by this combination.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a recording / reproducing apparatus showing a specific embodiment of a disk-shaped recording medium recording method of the present invention.

FIG. 2 is an explanatory diagram of FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 PCM modulator 2 MFM modulator 3 Synchronous signal modulator 4 Gate circuit 5 Pilot signal oscillator 6, 9 Waveform shaper 7 FM demodulator 8 Bandpass filter 10 Controller 11 Reference oscillator 12 Disk drive motor 13 Disk-shaped recording medium

Claims (3)

[Claims] 1. When recording a synchronization signal of a modulation method different from that of a data signal on a meandering track, the distances of the synchronization signal on the disk are substantially equal, and the recording band of the synchronization signal is the recording band of the data signal. A disk-shaped recording medium recording method for recording more narrowly. 2. The disk-shaped recording according to claim 1, wherein the modulation method of the synchronization signal portion is an FM signal method modulated by a predetermined signal, and the FM signal is recorded in a band narrower than that of the data signal portion. Medium recording method. 3. When recording a synchronizing signal of a modulation method different from that of the data signal on a meandering track, the synchronizing signal has a substantially equal distance on the disk and the recording band of the synchronizing signal is the recording band of the data signal. Recording is performed more narrowly, the synchronizing signal is detected from the disc-shaped recording medium, the output of the detected synchronizing signal and the output of the reference oscillator are compared, and the period of the synchronizing signal is detected so as to be constant. A recording / reproducing method for a disc-shaped recording medium whose rotational speed is controlled.