JPH0922531A - Information recording an reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the sure and quick recording/reproducing operation by using a disk which is capable of mass-production and constituted so that the information regarding the condition of a laser power at the time of recording is not erased erroneously. SOLUTION: The information regarding the reproducing condition of laser power at the time of recording obtained by reproducing an uneven pit of the already recorded part, on the surface of which a vertical magnetized film is formed, is supplied to a control circuit 24, then the condition of the recording power of a semiconductor laser 10 is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus for recording information on a disc formed by forming a concavo-convex array of laser power conditions during recording.

[0002]

2. Description of the Related Art Conventionally, in a recording disk typified by a magneto-optical disk, the recording condition is recorded for each disk after manufacturing the disk, as disclosed in Japanese Patent Laid-Open No. 59-81671. Was common.

[0003]

However, recording the recording conditions for each disc requires a great amount of work and is not suitable for mass production. Furthermore, if information is erroneously recorded on a track on which recording conditions are recorded, the recording conditions may be erased by overwriting. Therefore, a disk which is excellent in mass productivity and has no risk of erroneous erasure and a recording device which records information on the disk are required.

[0004]

Therefore, in the disk recording apparatus of the present invention, a guide for a recording track is provided on the surface of a plastic substrate, and a concavo-convex array containing information on the condition of the laser power at the time of recording at a position preceding the guide. In an information recording / reproducing apparatus for recording information on a disc formed by forming a recording film on the surfaces of the guide and the concavo-convex array, the concavo-convex array is used as a recording / reproducing pickup before the recording operation is started. Optical reproduction is performed to detect the condition of the laser power at the time of recording, and control means for setting the laser power at the time of recording of the recording / reproducing pickup based on the detected condition of the laser power at the time of recording is provided. Characterize.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view of an information recording medium, FIG. 4 is a perspective view, FIG. 2 is a diagram showing a format in which information relating to recording and reproduction conditions is recorded, and FIGS. FIG. 1 is a block diagram of an information recording / reproducing apparatus to be used.

In FIG. 1, reference numeral 1 denotes a magneto-optical disk (information recording medium). A through hole 2 is provided in the central portion, and this through hole 2 is clamped by an information recording / reproducing device.
The disc 1 is rotated. 3 is a magneto-optical recording portion,
The structure is as shown in FIG. That is, a perpendicular magnetic film 5 (shown by hatching) of GdTbFe, TbFeCo or the like is provided by vapor deposition or sputtering on a plastic substrate (polycarbonate, acrylic) 4 in which a guide groove 4a (this portion becomes a recording track) is formed. . A protective layer 6 made of a dielectric material is formed on the perpendicular magnetization film 5.

Inside the magneto-optical recording portion 3, there is provided an already-recorded portion 7 in which information signals relating to recording and reproducing conditions are recorded. The method of recording the information signal on the recorded portion 7 is a method of recording as uneven pits 8 on the plastic substrate 4 like a compact disk, or removing the perpendicular magnetization film 5 like a write-once disk. The recording method can be considered. In addition, an aluminum reflection film may be formed in place of the perpendicular magnetization film in this recorded portion.

According to the recording method described above, an already recorded information signal can be read by a change in the amount of light reflected from the disk 1. The method of recording in the form of uneven pits is advantageous because the pits can be formed when the guide groove 4a is formed and there is no risk of erasing.
The laser light is emitted from the plastic substrate 4 side as shown by arrow A.

As a format in which information relating to recording and reproduction conditions is recorded, in a device that can also use a compact disc, the subcode Q of the compact disc is used.
Use channel format. The format of the subcode Q channel is as shown in FIG. Of these, 0001 and 001 in 4 bits of the address
0,0011 is a significant pattern for compact discs, while other patterns are meaningless for compact discs.

Therefore, the recorded portion 7 of the magneto-optical disk 1 is
For example, 1000 patterns are recorded in the address portion of the subcode Q channel format. Information on recording (including erasing) and reproducing conditions of the magneto-optical disk is recorded in the 72-bit data portion. This information relates to the laser power, the linear velocity, the strength and direction of the bias magnetic field at the time of recording, erasing, and reproducing, for example. It is also possible to record a specific pattern to indicate the start of the magneto-optical recording portion 3 (or the end of the recorded portion 7). That is, the specific pattern is used as a mark indicating the reference position, and the data of the number of rotations and the time until the start of the magneto-optical recording portion are recorded.

The conditions for recording and reproduction are required for the following reasons. That is, as the material of the perpendicularly magnetized film of the magneto-optical disk, as described above, GdFe, TbFe, and Tb are used.
There are FeCo and the like, but if the composition is different, the conditions of the laser power and the bias magnetic field are naturally different, and TbF
This is because even with a material based on eCo, the Curie point rises as the proportion of Co increases, so the laser power for recording and erasing must also be increased.

Therefore, if the laser power at the time of recording, erasing, and reproducing, the intensity of the bias magnetic field at the time of recording and erasing, or the required linear velocity is written in the recorded portion 7, the information recording / reproducing apparatus can be used as a recording material. To different types of magneto-optical disks. In addition, even if the recording materials are the same, the magnetization direction of the magneto-optical recording portion in the non-recorded state may be different depending on the standard. Therefore, information that specifies the direction of the bias magnetic field during recording and erasing is recorded. What is done is effective.

Next, a first embodiment of an information recording / reproducing apparatus using the above disc will be described with reference to FIG.
In FIG. 3, reference numeral 10 denotes a semiconductor laser as a laser light source;
11 is a collimator lens, 12 is a first polarizing beam splitter, 13 is an objective lens, 14 is a disk, and 15 is 1
/ 2 wavelength plate, 16 is a polarization beam splitter, 17, 18
Is a photodetector, 19 and 20 are changeover switches for switching the outputs of the photodetectors 17 and 18, 21 is an adder (non-differential reproducing circuit), 22 is a differential amplifier (differential reproducing circuit), and 23 is A decoder, 24 is a control circuit. Further, 25 is a bias magnetic field applying means. When a disk (information recording medium) is mounted, there are two possibilities of this disk: a magneto-optical disk and a compact disk. Therefore, the information recording / reproducing apparatus reads the recorded state of the magneto-optical disk or the read-in state of the lead-in part of the compact disk. Becomes

That is, each of the changeover switches 19 and 20 is a
And the outputs of the photodetectors 17 and 18 are
Only applied to. Then, since the pickup 26 is at the reading start position, the intensity of the reflected light from the disk changes in accordance with the information recorded in the lead-in portion or the recorded portion. Since the outputs of the photodetectors 17 and 18 change according to this strength change, a reproduction HF signal can be obtained by adding the outputs of the photodetectors 17 and 18 (one photodetector with a large output change is used. May be).

The reproduced HF signal is decoded by a decoder 23 and supplied to a control circuit 24. The control circuit 24 controls the device according to the read information signal. First, when the address 4 bits of the subcode Q channel is 1000 as described above, it is determined to be a magneto-optical disk, and the changeover switches 19 and 20 are selected.
Is controlled to select the b side.

In the case of a magneto-optical disk,
Information regarding recording and reproduction is read, and the semiconductor laser 10, the bias magnetic field generating means 25, and the spindle motor for rotating the disk are controlled by the control circuit according to the information. That is, while the information is being read from the recorded portion 7, the changeover switches 19 and 20 must select the a side. Therefore, in a medium in which a specific pattern is recorded at the end of the recorded portion 7, the changeover switches 19 and 20 may be switched to the b side by detecting this specific pattern. At the same time, the counter value indicating the position of the pickup 26 is cleared. If data relating to the time up to the start of the magneto-optical recording portion 3 is recorded, this data may be read and switched to the b side after a predetermined time has elapsed. The above operation is easily realized by the control circuit 24 (comprising a microcomputer or the like).

When the magneto-optical disk is mounted on the information recording / reproducing apparatus, the above-described determination is first performed. When the reproducing operation is designated, the semiconductor laser 10 is supplied with a predetermined power under the control of the control circuit 24. The light from the semiconductor laser 10 is converted into parallel rays by the collimator lens, and the S-polarized light component is reflected by the first polarization beam splitter 12 to become linearly polarized light (P-polarized light component). This linearly polarized light is
The light is condensed by 3 and irradiates the magneto-optical recording portion of the magneto-optical disk 14, and the plane of polarization of the reflected light rotates according to the recorded information. In this reflected light, the P-polarized light component is changed by about ± 0.3 degrees (that is, the S-polarized light component is generated). When the light again enters the first polarization beam splitter 12, the P polarization component is reflected by about 30%,
The change in the rotation angle is enlarged by reflecting 100% of the polarized light component.

The reflected light in which the change in the rotation angle is magnified is 1/2
The plane of polarization is rotated by the wave plate 15, and then separated into the P-polarized component and the S-polarized component by the second polarizing beam splitter 16 and incident on the corresponding photodetectors 17 and 18, respectively. Then, by supplying the outputs of the photodetectors 17 and 18 to the differential amplifier 22, a magneto-optical reproduction HF signal is obtained.

On the other hand, when a recording or erasing operation is designated after the mounting of the magneto-optical disk, the laser power, the strength and direction of the magnetic field, and the state of the disk rotation control according to the mode are determined based on the read information. Set by the control circuit. Also, the start position of the magneto-optical recording portion is set and used for subsequent access. Then, recording and erasing operations are performed.

If 1000 is not recorded in the 4-bit address of the subcode Q channel, it is determined that a compact disc is loaded, and the changeover switch 1
The a side is still selected for 9 and 20, and the HF signal of the compact disc is obtained from the adder 21.

In the above embodiments, a magneto-optical disk is used as an information recording medium. However, the present invention is applicable to an additional type optical disk or the like in which the reflectance is changed by irradiating light or removing the recording film or changing the property. You may use it. or,
The information regarding the condition may be recorded in a portion other than the reading start portion. Further, the configuration of the information recording / reproducing apparatus may be configured as shown in FIG. 5 (second embodiment).

[0022]

As described above, according to the present invention, it is possible to reliably record information on a disc in which the laser power condition at the time of recording can be recorded by a method suitable for mass production and the condition is not erased by mistake. Can be recorded.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a disc of the present invention.

FIG. 2 is an explanatory diagram of a recording format of a disc of the present invention.

FIG. 3 is a playback circuit block diagram of the disk recording / playback apparatus according to the first embodiment of the present invention.

FIG. 4 is a cutaway perspective view of an essential part of the present invention.

FIG. 5 is a reproduction circuit block diagram of a disk recording / reproducing apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Magneto-optical disk 3 Magneto-optical recording part 4a Guide groove 7 Pre-recorded part 8 Pit 10 Semiconductor laser 24 Control circuit

Claims (1)

[Claims] 1. A guide for a recording track and a concavo-convex row containing information relating to a laser power condition at the time of recording are formed at a position preceding the guide on a surface of a plastic substrate.
In an information recording / reproducing apparatus for recording information on a disc having a recording film formed on the surface of the guide and the concavo-convex row, the concavo-convex row is optically reproduced by a recording / reproducing pickup before starting a recording operation. Information recording characterized by including a control means for detecting the laser power condition at the time of recording and setting the laser power at the time of recording of the recording / reproducing pickup based on the detected condition of the laser power at the time of recording. Playback device.