JPH0644563A - Optical disk recorder - Google Patents

Abstract

PURPOSE:To improve a reproduction characteristic by providing a means which performs a test recording at an optical disk position to be recorded and determines an optimum recording power for the optical disk and a means erasing an area performing a test record. CONSTITUTION:A recorded information on a magneto-optical disk 1 is read by an optical pickup 3 and added to an EFM demodulating circuit 6 through an HF signal detecting circuit 5. The output of the circuit 6 is added to a system control section 8 through a subcode extracting circuit 7 and guided to an output terminal 10 through a demodulating circuit 9. At the time of record, an EFM modulating circuit 11 adds the subcode signals from the section 8 through a subcode inserting circuit 12 and also adds recording signals from a recording information input terminal 13 through an A/D converter 14 and a modulation signal processing circuit 15. The output of the circuit 11 is added to a magnetic modulation circuit 16, the optical pickup 3 reversely placed against the magnetic disk 1 adds heat and a magnetic head 17 changes the direction of a vertical magnetization of the recording film and records the information.

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 apparatus, and more particularly to a method for determining an optimum laser power for an optical disk.

[0002]

2. Description of the Related Art Conventionally, compact discs (C
There is D). In recent years, research on recording films has been actively conducted, and recordable optical discs have been developed. Along with this, there is a recorder for recording on the optical disc having the recording film which can be freely recorded. An optical disc recorded by this recorder can be reproduced by a CD player as well as a reproduction-only CD. These optical discs were write-once types that could be recorded only once.

On the other hand, the practical use of a rewritable optical disk capable of erasing recorded information and re-recording has already started as an external storage memory device of a computer. As one of them, in recording on a magneto-optical disk, a laser beam is used as a light source, and an external magnetic field positioned opposite to the light source is applied to the recording film to change the direction of perpendicular magnetization of the recording film for recording. For erasing, a magnetic field opposite to that used for recording is applied and laser light is applied to the recording film.

On the other hand, in reproducing a magneto-optical disk, a magneto-optical phenomenon called the Kerr effect is used to read the direction of magnetization. When linearly polarized laser light is incident on the perpendicularly magnetized film, the plane of polarization of the reflected light slightly rotates left or right according to the direction of magnetization. Information is reproduced by converting this rotation into a light amount change by an analyzer. The present invention is
It relates to the recording power, which is an important factor when recording on such a recordable optical disc.

When recording on a recordable optical disk, the recommended recording laser power value specific to the optical disk is pre-formatted on the optical disk as disk information. In the device, in the case of a recordable CD format, in order to read this information and determine the optimum recording laser power for the mounted optical disk, the power calibration area, which is the same as the previous one, is read from the optical disk.
As indicated by the read time code information, move the optical pickup to this position, and in the designated area,
Test recording is performed by changing the recording laser power value in several steps.

Then, the test-recorded optical disk portion is reproduced and the asymmetry of the HF signal of each portion recorded with different recording power is measured. Here, the optimum power of the optical disk and the device is determined by selecting the recording power that is the best when the value of asymmetry obtained by the reproduction is reproduced.

[0007]

However, since the power calibration area, which is an area for test recording for determining the optimum recording power, naturally has a range, the number of uses is limited. If this area is used up, there is no test recording area in order to determine the optimum recording laser power for the device and the optical disc, so recording is performed in the program area with the optimum recording power. It becomes impossible.

Further, here, the optimum recording power obtained by the test recording is recorded in the program area which is an area for actually recording the music signal, the data and the like. What is the power calibration area? , The radial positions of the optical disc are different. The power calibration area is located on the inner circumference of the optical disc, but the program area has a radius of 25 mm in the CD format.
Up to 58 mm.

This is the optimum recording power value obtained by test recording in the power calibration area. Even if recording is performed in the program area, the actual radial position to be recorded is different, so that there is a difference in tilt of the optical disc. There is a problem that the recording characteristics are affected and the optimum recording state in the program area is not always obtained.

[0010]

Therefore, an optical disk recording apparatus according to the present invention provides a means for recording a recording signal in a user recordable area of an optical disk, and an optimum recording laser power for the optical disk when recording the recording signal. In the optical recording apparatus having a determining means, there are provided means for performing test recording at the optical disk position where the recording signal is to be recorded, means for determining the optimum recording power on the optical disk, and means for erasing the test recorded area. It is characterized by being provided.

[0011]

Therefore, with the above configuration, power calibration can be performed at the position of the optical disk where recording is actually performed. Therefore, even if the recording state changes depending on the radial position, the optimum recording state can be maintained, and even if the power calibration area is used up, the optimum recording state can be similarly maintained.

[0012]

1 is a block diagram of an erasable optical disk device according to the present invention. Here, a magneto-optical disk device will be taken up and its configuration will be briefly described. In the figure, the magneto-optical disk 1 is
It is CLV controlled to give the required speed. The recorded information on the magneto-optical disk 1 is read by the optical pickup 3 and applied to the EFM demodulation circuit 6 via the head amplifier 4 and the HF signal detection circuit 5.

The output of the EFM demodulation circuit 6 is applied to the system control section 8 via the sub-code extraction circuit 7, and the music signal is demodulated via the demodulation circuit 9 to be output to the output terminal 10. During recording, the EFM modulation circuit 11 receives the subcode signal from the system control unit 8 via the subcode insertion circuit 12, and the recording signal from the recording information input terminal 13 to the A / D converter 1.
4 and the signal processing circuit 15 for modulation. E
The output of the FM modulation circuit 11 is applied to the magnetic modulation circuit 16, and heat is applied by the optical pickup 3 arranged opposite to the magneto-optical disk 1 so that the magnetic head 17 changes the direction of perpendicular magnetization of the recording film for recording.

In reproduction, in order to read the direction of magnetization,
As described above, the magneto-optical phenomenon called the Kerr effect is used, converted into a light amount change by the analyzer, read by the optical pickup 3, and reproduced as described above. on the other hand,
To move the optical pickup 3, a slide control signal from the system controller 8 is applied to the slide device 19 via the slide drive 18. Optical pickup position detection output from the slide device 19, and optical disc sensor 20
The detection outputs of the optical disk 1 mounted from the above are respectively added to the system control unit 8.

Next, the optical configuration of the magneto-optical disk is shown in FIG. 2 and will be briefly described. In the figure, the multimode laser light emitted from the semiconductor laser 21 passes through a collimator lens 22 and a beam shaping prism 23, and then a special beam splitter 24 purifies the linearly polarized component of the laser light and separates weak signal light. I do. This is different from a usual beam splitter in that only the S component is reflected by 100%, but the P component is transmitted and reflected by 50%.

In other words, the P component wave of the reading laser beam applied to the information recording surface of the magneto-optical disk shifts according to the disk recording information and is reflected as an S component wave. Is very small, the S component which is reflected from the magneto-optical disk 1 and re-enters the beam splitter 26 is 100% reflected and sent to the photodiodes 32a and 32b which are the signal detection optical system. I have it.

Since the P component is reflected directly from the magneto-optical disk 1, a part of this P component is collected by the condenser lens 2.
A focus error signal and a tracking error signal are produced by the photodiode 32c through 7 or the cylindrical lens 28. As a light receiving optical system,
The 100% S component reflected by the special beam splitter 24 and the P component of about 50% are divided into an information signal detection system and a focus tracking control signal detection system,
The former is further guided to a differential optical system.

That is, the S component is put in the half-wave plate 29 to rotate the polarized light, divided into two orthogonal linearly polarized lights by the ordinary polarization beam splitter 30, and the mutual outputs are passed through the condenser lens 31. It is put in the photodiodes 32a and 32b, and the difference between the outputs is used as an information signal. The latter is guided to the focus error signal detection optical system and the tracking error detection optical system.

Now, a block diagram of the area of the magneto-optical disk 1 according to the present invention is shown in FIG. In the figure, the power calibration area (PCA) 36 is the innermost circumference, and the TOC area (tune table of contents information area) 3 on the outer circumference.
7 and a recording data area 38. Audio signals and memory data are recorded in this area. Area 38 already
a has already been recorded, and the data to be recorded next is area 38a.
In the case of the outer circumference of the magneto-optical disk, naturally, recording is performed subsequent to the already recorded area 38a. However, in determining the recording power here, test recording is performed in the power calibration area (PCA) 36, and the magneto-optical disk is recorded. 1 and the optimum recording power of the apparatus are determined.

However, as described above, the recording power determined by the power calibration area is not always optimum because the recording power changes depending on the radial position of the magneto-optical disk 1. Therefore, in the present invention, in this case, the power calibration is further performed on the outer periphery of the area 38a. In the figure, point X1 is the area. If the amount of data to be recorded next is recorded in advance, it is appropriate to perform it in the middle. In other words, it is better to perform around the radial position corresponding to half of the amount of data to be recorded from now on.
desirable.

This is because if the recording power is determined at a radial position just in the middle of the recording start radial position and the recording end radial position of the data to be recorded, the recording state will be even. is there. After the power calibration is completed and the optimum recording power is determined, in the overwritable system, the recording standby state is maintained. Then, when there is a recording start command, recording is started. In the area used for power calibration, that is, the point X1, the recording signal is overwritten as it is.

In a system that cannot be overwritten, the area used for power calibration is erased. Then, the recording standby state is set. The subsequent steps are the same as described above. The area used for power calibration is a very small part of the amount of recorded data. As described above, even if the power calibration is performed in the recording data area, the area is used as though it is not used at all, and the recording data can be recorded in an optimum recording state without depending on the radial position of the optical disc. You can record.

[0023]

As described above, by constructing and operating as in the present invention, it becomes possible to determine the optimum recording power by performing test recording near the radial position of the optical disc to be actually recorded. It is possible to guarantee a good record of.

[Brief description of drawings]

FIG. 1 is a block diagram of an erasable optical disk device of the present invention.

FIG. 2 is a schematic configuration diagram of a magneto-optical disk and an optical system.

FIG. 3 is an area configuration diagram of a magneto-optical disk according to the present invention.

[Explanation of symbols]

1 magneto-optical disk 2 spindle motor 3 optical pickup 4 head amplifier 5 HF signal detector 6 EFM demodulator 7 subcode extractor 8 system controller 9 demodulator 10 playback signal output 11 EFM modulator 12 subcode inserter 13 recorded information Input 14 A / D converter 15 Signal processing device 16 Magnetic modulator 17 Magnetic head 18 Slide drive unit 19 Slide device 20 Disk sensor 21 Semiconductor laser 22 Collimator lens 23 Beam shaping prism 24 Special beam splitter 26 Polarization beam splitter 27 Condenser lens 28 Cylindrical lens 29 Half-wave plate 30 Polarizing beam splitter 31 Condensing lens 33 Mirror 34 Objective lens 35 Magnetic head 36 Power calibration area 37 TOC area 32a, b, c Doo diode 38,38a record data area

Claims (3)

[Claims] 1. An optical recording apparatus comprising: a unit for recording a recording signal in a user recordable area of an optical disc; and a unit for determining an optimum recording laser power for the optical disc when recording the recording signal. An optical disk recording apparatus comprising: a means for performing test recording at an optical disk position where a signal is to be recorded and determining an optimum recording power for the optical disk; and a means for erasing the test recorded area. 2. An optical disk recording apparatus, wherein the erasing means of the test recording area is performed by an inverse magnetic field and laser light. 3. The optical disk recording apparatus, wherein the erasing means of the test recording area is performed by overwriting a recording signal.