JP2997115B2 - Optical disk and optical disk device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording on a disk substrate.
A single optical track is applied to a phase-change optical disc having tracks.
Erasing or recording information by changing the beam intensity of the beam
Or the optical disk and optical disk device
I do.

[0002]

2. Description of the Related Art Hitherto, a disk-shaped optically recorded information carrier (hereinafter referred to as an optical disk) having a write-once type recording film and an optical information recording / reproducing apparatus for writing information on the optical disk have been proposed. Various proposals and announcements have also been made regarding erasable optical disks having a recording film and devices therefor.

Hereinafter, a conventional optical information recording / reproducing apparatus for optically recording / reproducing information on / from an optical disk having an erasable phase-change recording film will be described.

As shown in FIG. 7, the optical disc 1 comprises a spiral guide groove 1A extending from the outer periphery to the inner periphery and address portions 1B arranged radially. The address portion 1B is configured as a part of the guide groove, and stores information indicating the position of each of the guide grooves. Information is recorded in the data area of the guide groove portion 1A between the address portions 1B, the mark portion of the recording film is in an amorphous state, and the reflectance is lower than the crystalline state of the portion other than the mark portion. Is accumulating.

An optical information recording / reproducing apparatus for recording / reproducing on / from this optical disk has been conventionally proposed. FIG. 5 shows a configuration diagram of this conventional optical information recording / reproducing apparatus, and FIG. 6 shows signal waveforms of various parts of the conventional example.

The optical disk 1 has a turntable motor 2
The motor is rotated at a constant rotation speed (for example, 1800 rpm) by the turntable motor control circuit 3. The optical pickup 4 includes an optical system including a semiconductor laser, an objective lens, a lens, a mirror and a polarizing beam splitter, and an actuator for moving the objective lens in a vertical direction and a radial direction. A part of the light beam emitted from the semiconductor laser is monitored by a light detector in the optical pickup 4, and the output of the light detector is input to a semiconductor laser control circuit 5. Reference numeral 5 controls the intensity of the light beam emitted from the semiconductor laser 5. When information is optically reproduced from the optical disk 1, the intensity of the light beam A "is adjusted even if the light beam A" is focused and irradiated onto the recording film surface of the optical disk 1. When setting a low beam intensity that does not change the state of the recording film and optically overwriting information on an optical disc,
The intensity of the light beam A ″ is set to an appropriate beam intensity that causes a change in the state of the recording film.

When the optical disc 1 rotates, the optical pickup 4
The distance between the objective lens of the optical disk 1 and the recording film of the optical disk 1 changes, and the light beam A ″ cannot always be focused on the recording film of the optical disk 1. Since the light beam cannot always be irradiated on the upper information track, it has a focus and tracking servo system composed of a focus servo circuit 6, a tracking servo circuit 7, and an optical pickup 4. A "can be focused.

Further, the optical pickup 4 has a moving device 8 composed of a linear motor or the like, and moves the optical pickup 4 at an arbitrary radial position on the optical disc 1 so that the light beam A ″ emitted from the optical pickup 4 follows the information track. The optical disk 1 is moved in the radial direction so that information can be read from any position on the optical disk 1 and recorded.

[0009] Information to be recorded is 1024 per sector.
It has a capacity of bytes, and error correction data is added by an error correction circuit 9, and is added to a modulation / demodulation circuit 10. In the modulation / demodulation circuit 10, the recording data is modulated based on, for example, the RLL (2, 7) modulation method, and then a frame signal and a sync signal for bit synchronization are added for each fixed data length of, for example, 16 bytes. The format is as shown in FIG. The frame signal is included in each of the data section and the ECC section. The output (a) of the modulation / demodulation circuit 10 and the erase signal (d) from the drive controller 11 are input to the semiconductor laser control circuit 5. Semiconductor laser control circuit 5
6A, the intensity of the light beam is modulated in two steps as shown in FIG. 6A, and this light beam A "is irradiated on the recording film surface of the optical disk to record information while erasing, that is, to perform overwrite recording. .

At this time, the recording film of the optical disk which has been irradiated with the recording power intensity of the light beam shifts from a crystalline state to an amorphous state, and a recording mark portion is formed. Conversely, the recording mark portion that has been irradiated with the erasing power intensity changes from an amorphous state to a crystalline state, and the recording mark portion is erased.

At the time of reproduction, a reproduction signal from the optical pickup 4 is input to a binarization circuit 12, and an output of the binarization circuit 12 is input to an address read circuit 13 and a modulation / demodulation circuit 10, so that address data and information can be read. Done.

[0012]

Conventionally, in a recording / reproducing apparatus for an optical disk having a phase-change type recording film, it is necessary to record information with a recording modulated light having a light intensity as shown in FIG. If overwrite recording is performed many times in the same location, the reproduction signal is disturbed at the beginning and end of the recording signal area due to the difference in the intensity of the irradiation light beam to the recording area and the non-recording area. In particular, when the reproduction signal is digital information for a computer, an error correction code is added to maintain the reliability of the information, and even if digital data is lost in the reproduction signal due to a defect on the disk. Although the reliability of the information is guaranteed by error correction, the digital data in the reproduced signal is always recorded at the beginning and end of the recording modulation signal area when the above condition occurs. The format of the normal recording modulation signal has a sync portion at the head as shown in Fig. 6. Therefore, even if a part of the start end is lost, PLL synchronization is performed in the modulation / demodulation circuit 10. In addition, the influence of signal degradation can be reduced by extending the time of the sink part, but the termination part is usually a part of the ECC part or the data part, and the degradation of this part progresses. If digital data in other portions is lost simultaneously, correct information cannot be extracted from the reproduced signal.

The present invention has been made to solve such a problem, and has a problem that a re-recording signal generated at the end of a recording signal for recording information is generated.
Make sure that the raw signal disturbance does not
Thermal balance before and after the end of the
Even if bar light recording is performed, the progress of signal degradation is suppressed,
Optical discs and optical discs that can store highly reliable information
The purpose is to provide a disk device.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a conventional optical information recording / reproducing apparatus in which a dummy signal is added to an end portion of a recording modulation signal and an erasing signal is modulated to form an optical disk. Overwrite recording is performed, and information is reproduced from the reproduction signal without using the signal disturbance at the end of the reproduction signal from the optical disk. The configuration is such that thermal balance is maintained and the progress of signal deterioration is suppressed.

[0015]

With this configuration, in the optical information recording / reproducing apparatus for the phase change optical disk, the deterioration of the reproduction signal from the optical disk due to the increase in the number of overwrites at a specific portion, particularly the influence of the disturbance of the signal at the end of the reproduction signal. Can be eliminated or reduced.

[0016]

【Example】

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an optical information recording / reproducing apparatus according to the first embodiment, and FIG. 2 shows signal waveforms at various parts in the first embodiment.

The digital output (a) of the modulation / demodulation circuit 10 is input to a dummy signal generation circuit 14 and an addition circuit 15. The dummy signal generation circuit 14 detects the end of the signal in one sector, generates a digital output (b) of the dummy signal, and generates a dummy signal at the end of the output (a) of the modulation / demodulation circuit 10 by the addition circuit 15. A digital signal (c) to which the output (b) of the circuit 14 is added is generated.

In the first embodiment, the dummy signal (b) is formed by inputting the clock signal CK from the modulation / demodulation circuit 10 to the dummy signal generation circuit 14 and having the same frequency as the sync signal.

The erasing signal (d) from the drive controller 11 is input to an erasing time setting circuit 16, and the erasing time setting circuit 16 determines that the terminal end of the erasing signal (d) is longer than the time width T of the dummy signal (b). An extended signal (e) is generated,
The output (c) of the addition circuit 15 is input to the semiconductor laser drive circuit 5.

When recording information on the optical disk 1, the beam intensity is changed as shown in FIG. With the above-described configuration, the reproduced analog signal (f) is not affected even if the overwrite recording is performed many times on the same sector in the optical disc 1 and the reproduced analog signal (f) of the optical pickup 4 is disturbed. In this case, only the portion corresponding to the dummy signal is not affected, and the portion for accurately extracting information is not affected.

In the first embodiment, the function of adding the dummy signal and the output of the modulation and demodulation circuit is performed by an external circuit other than the modulation and demodulation circuit. However, the modulation and demodulation circuit is constituted by a microcomputer or the like, and the functions of generating and adding the dummy signal are performed. It can be built in, and similarly, the function of setting the erasing time can be built in the drive controller.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 shows the second embodiment.
FIG. 4 shows a signal waveform of each part of the second embodiment, and the same components as those of the conventional example are denoted by the same reference numerals.

The erasure signal (d) from the drive controller 11 is input to the erasure signal modulation circuit 17 and the modulation / demodulation circuit 1
The output (a) of 0 is modulated into an output (g) as if a step was prolonged from the terminal end. The output (g) of the erasing signal modulation circuit 17 and the output (a) of the modulation / demodulation circuit 10 are applied to the semiconductor laser drive circuit 5, and are applied to the terminal of the output (a) of the modulation / demodulation circuit 10 as shown at A 'in FIG. The semiconductor laser is controlled so that the erasing power of the beam increases stepwise at the corresponding portion. The rate of increase of the erasing power is in the range of 15% to 50% of the difference between the erasing power and the recording power before the change.

With the above-described configuration, even if overwrite recording is performed many times in the same sector in the optical disc 1, a portion corresponding to the terminal end of the output (a) of the modem 10 is thermally heated. The balance is maintained, the disturbance of the reproduced analog signal (h) of the optical pickup 4 is reduced, and the information can be accurately extracted.

[0025]

As is apparent from the above embodiments, according to the present invention, a signal is recorded at the end of a recording signal for recording information.
Add a part of the signal included in the recording signal as a dummy signal.
By doing so, the thermal balance before and after the end of the recording signal can be balanced.
Signal deterioration even after performing overwrite recording many times
Optical data that can suppress the progress of
A disk and an optical disk device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an optical information recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram of each part of the apparatus shown in FIG.

FIG. 3 is a block diagram showing a configuration of an optical information recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 4 is a waveform diagram of each part of the apparatus shown in FIG.

FIG. 5 is a block diagram showing a configuration of a conventional optical information recording / reproducing apparatus.

FIG. 6 is a waveform diagram of each part of the conventional device.

FIG. 7 is a schematic diagram of a main part of an optical disk.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 4 Optical pickup 5 Semiconductor laser control circuit 14 Dummy signal generation circuit 15 Addition circuit 16 Erase time setting circuit

Claims (4)

(57) [Claims] A recording track on a disk substrate;
A phase-change optical disc for erasing, recording, or reproducing information by changing the beam intensity of a single light beam, wherein a part of a signal included in the recording signal is provided at an end of a recording signal for recording information. An optical disc characterized by adding and recording a dummy signal as a dummy signal, and providing an erase section after the dummy signal recording section. 2. An optical disk device for erasing, recording, or reproducing information by changing the beam intensity of a single light beam on a phase-change optical disk having recording tracks on a disk substrate, wherein the optical disk device is generated by a light source. An optical pickup that irradiates a light beam onto the recording track; and a signal adding unit that adds a part of a signal included in the recording signal to an end portion of a recording signal for recording information. An optical disc device for recording information according to a signal and an output of said signal adding means. 3. It has a recording track on a disk substrate,
A method of recording information on a phase-change optical disc for erasing or recording or reproducing information by changing the beam intensity of a single light beam, wherein the recording signal is recorded at the end of a recording signal for recording information. An information recording method , wherein a part of the included signal is added as a dummy signal and recorded on the recording track. 4. An optical disk device for erasing, recording, or reproducing information by changing the beam intensity of a single light beam on a phase-change optical disk having a recording track on a disk substrate, wherein the information is generated by a light source. An optical pickup that irradiates a light beam onto the recording track; and an erasing signal that extends an erasing signal from an end of a recording signal for recording information, and that the extended erasing signal has a greater intensity in a range smaller than the recording signal. and a modulating means, at the time of recording according to an output of said recording signal and said erase signal modulating means
An optical disk device characterized by recording information.