JP2001023170A - Information recording method in multilayer recording medium - Google Patents

Abstract

(57) [Summary] [PROBLEMS] By recording information, large fluctuations in the amount of laser light due to scattering and absorption when the laser light passes through the recorded recording layer and information of the already recorded recording layer can be reduced. There were problems such as being destroyed. A recording layer through which a laser beam passes by recording information in reverse to a three-dimensionally arranged information recording layer to which the laser beam sequentially arrives based on a direction in which the laser beam is incident. Record information is not destroyed, and
The variation can be changed only by a constant change in the amount of light by passing through a plurality of recording layers.

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 / reproducing information on / from an information recording medium, and more particularly to an information recording method and an information recording / reproducing apparatus for recording information by a recording method using laser beam recording. Things.

[0002]

2. Description of the Related Art As a technology for recording and reproducing information on an information recording medium by using a laser beam, an optical disk device or the like has already been put into practical use. There is a phase change type optical disk utilizing a reversible state change between the optical disks. In order to obtain these two states, the information recording medium is heated to a temperature higher than its melting point by irradiating a high power (recording power) and then rapidly cooled to an amorphous state. After irradiating (erasing power) to raise the temperature of the information recording medium to the crystallization temperature, the medium is gradually cooled to be in a crystalline state, and overwriting can be performed by a single laser beam.

[0003] Conventionally, with respect to information recording by the recording method described above, DVD Specifications for Rewritable Disc (DV
(D-RAM) Part 1 Physical Specifications Version 1.0
As described in (PH-17), a recording layer on which information is recorded is laminated and has two recording layers, and recording and reproduction on each recording layer is a method of irradiating laser light in opposite directions. However, this is not a recording method for recording from one direction. For the read-only operation for reading information, refer to DVD Specificati
ons for Read-Only Disc (DVD-ROM) Part 1 Physical S
As described in pecifications Version 1.0 (PH-28 to PH-39), the playback layer to be played back has a three-dimensional two-layer structure,
This is a method in which information is read from the side closer to the incident position of the laser light, and thereafter, the information farther from the incident position of the laser light is read out.

[0004]

The above-mentioned prior art does not take into account a recording method of a multilayer structure in which a plurality of recording layers for storing information are three-dimensionally arranged with respect to a method for recording information. Due to the recording, there are problems such as large fluctuations in the amount of laser light due to scattering and absorption when the laser light passes through the recorded recording layer, and destruction of information of the already recorded recording layer.

[0005] Further, a recording layer having a multi-layered structure in which a plurality of recording layers for storing information are arranged in a three-dimensional manner, the recording area is subdivided, and the rotation of the recording medium needs to be controlled in accordance with the subdivided recording area. In the method, by recording information in a recording layer having a multilayer structure as in the read-only information reading method, at the time when the information has been recorded on the recording layer from the inner periphery toward the outer periphery, from the outer periphery. It is necessary to move the laser light or the recording medium toward the inner circumference, and when the rotation is controlled by the M-CLV (Modified Constant Linear Velocity) method, it is necessary to increase the number of rotations about twice. Since these operation times are extremely long, the time involved in recording and reproducing information is also long, and there has been a problem that the information transfer rate is greatly reduced.

An object of the present invention is to solve the above-mentioned problems, and to consider the order of recording information in a multi-layer recording method in which a plurality of recording layers for storing information are three-dimensionally arranged. Accordingly, it is an object of the present invention to provide an information recording method for suppressing the time for moving the laser light or the recording medium and the time for controlling the rotation of the recording medium.

[0007]

In order to achieve the above object, an information recording method according to the present invention irradiates an oscillated laser beam onto an information recording medium so that information is recorded on a recording area on the information recording medium. A recording medium that stores information by forming a recording portion that is physically different from an unrecorded portion, and has a multilayer structure in which a plurality of recording layers in which information is stored are three-dimensionally arranged. In a recording method for recording information on a recording medium having a subdivided recording area, when recording information on a recording medium in which the amount of laser light changes greatly due to scattering and absorption by recording information, laser light is incident. The information is recorded on the opposite side of the recording layer of the three-dimensionally arranged information that the laser light sequentially reaches, based on the direction of the laser beam, so that the recording information of the recording layer through which the laser light passes is not destroyed. , One is that to be able to vary by only a certain amount of light caused by passing through the plurality of recording layers.

Further, information is recorded in a subdivided recording area in the plane of each recording layer, and a subdivision in the plane of the next recording layer is performed from a state where all recording areas of each recording layer are recorded. By recording information in a structured recording area and sequentially recording information on multiple recording layers arranged three-dimensionally, the rotation control time in the M-CLV (Modified Constant Linear Velocity) method can be suppressed. Things.

[0009]

Embodiments of the present invention will be described below. FIG. 1 shows an embodiment of the device configuration of the present invention. Here, 1 is a laser, 2 and 4 are lenses, 5 is a recording medium, 12 and 13 are photodetectors, 15 is a reproducing circuit, 20 is a laser driver, 21 is a power monitoring circuit, 22 is a servo drive circuit, and 23 is A controller 24 indicates a spindle drive circuit.

The information recording / reproducing apparatus includes an optical head centered on a laser 1, a recording medium 5 for storing information, a recording processing system centered on a laser driver 20, and a reproduced signal obtained from the optical head. It is composed of a reproduction processing system centered on a reproduction circuit 15 for converting information. The recording medium 5 includes a first recording layer 7, an intermediate layer 8, and a second recording layer 9 laminated on a substrate 6.
And a protective layer 10.

The command and information data from the upper host are decoded by the controller 23 and converted into a code string corresponding to the modulation and the modulation method of the recording data, and are transmitted to the laser driver 20. M-CLV (Modified Constant Linear Velocity) that changes the number of rotations of the recording medium for each zone and makes the recording density on the inner and outer circumferences approximately constant as a method of increasing the capacity
When a recording method called a system is adopted, it is necessary to control the rotation speed of the spindle with high accuracy in accordance with the zone for recording and reproduction.

A servo for controlling the position of a light spot for recording and reproducing information includes a cylindrical lens (not shown) disposed in front of the photodetector 12 and a photodetector (four-split) 1.
2 by the preamplifier 4 and the servo circuit 18
A focus error signal and a track error signal can be obtained. The error signal is input to the controller 23, a servo signal is output from the controller 23 to the servo drive circuit 22, and the actuator 11 is controlled by the servo drive circuit 22. The position of the light spot is controlled.

The high-frequency superimposing circuit 19 is provided to reduce laser noise caused by the laser 1. In recording / erasing, the high-frequency superimposing circuit 19 may suspend the high-frequency superimposition in terms of the life of the laser.

At the time of reproduction, the laser 1 oscillates at a low output and enters the recording medium 5. The light reflected from the recording medium 5 is split into an optical path by the prism 3 and is incident on the photodetector 12. After the photoelectric conversion by the photodetector 12, the signal is amplified by the preamplifier 14,
The signal is input to the reproduction circuit 15. The reproduction circuit 15 includes a waveform equalization circuit, an automatic gain control circuit, a binarization circuit, and the like, and converts an input reproduction signal into a binarization signal.

The binarized signal from the reproducing circuit 15 is input to a PLL (Phase Locked Loop) 16 for self-clocking. The reproduced clock and the binarized signal synchronized with the binarized signal obtained by the PLL 16 are input to the discrimination circuit 17 for data discrimination, and the resulting data discrimination signal is input to the controller 23. The data is demodulated.

When recording information, the controller 2
The recording pulse train modulated in accordance with the regular information data from No. 3 is output to the laser driver 20. The laser driver 20 causes the laser 1 to oscillate at a high output, and the light emitted from the laser 1 is converted into parallel light by the lens 2, passes through the prism 3, converges on the recording medium 5 by the lens 4, and corresponds to the code string. Record the recording mark.

FIG. 2 shows a method of detecting a focal point position in a multilayered recording medium according to the present invention. When the recording medium 5 is set on the spindle 25, the lens 4 is moved from the substrate 6 toward the protective layer 10 in the management area 40 provided on the inner periphery or the outer periphery of the recording medium 5, as shown in FIG. When the light spot passes through the first recording layer 7 and the second recording layer 9 as shown in the graph of the defocus amount and the amplitude of the focus error signal described on the lower side, the amplitude of the focus error signal becomes zero due to the downward slope. become. The defocus ΔL between these two points is the first recording layer 7
And the defocus amount of the second recording layer 9. By storing ΔL in the controller 23, the focal positions of the first recording layer 7 and the second recording layer 9 can be freely changed.

FIG. 3 shows an information recording method for a multi-layer recording medium according to the present invention. FIG. 3 shows a recording method in a zone n31 obtained by dividing the recording medium 5 in the radial direction, and shows a recording method called an M-CLV (Modified Constant Linear Velocity) method. In FIG. 3A, the light spot is moved to the start position of the zone n31 of the second recording layer 9 and the rotation speed of the spindle 25 is controlled by the spindle drive circuit 24. After the rotation speed of the recording medium 5 is controlled, the recording is started from the start position of the zone n31 of the second recording layer 9 and is performed up to the end position of the zone n31.

Next, the actuator 11 is controlled by the servo drive circuit 22 in order to move the focal position by ΔL described with reference to FIG. The light spot is directed from the second recording layer 9 to the first
After moving to the recording layer 7, the zone n3 of the first recording layer 7
FIG. 3B shows a state in which the light spot is moved to the start position of No. 1 and the recording is started, and the recording is performed up to the end position of the zone n31 of the first recording layer 7. Then, FIG. 3 (c)
The light spot is moved to the zone n + 1 32 as shown in FIG.
The focus position is moved by ΔL described in FIG. 2, the light spot is moved from the first recording layer 7 to the second recording layer 9, and recording is performed from the start position of zone n + 1 32 of the second recording layer 9. Start again.

By recording information from the second recording layer 9 as described above, the information can be accurately recorded without suffering large fluctuations in light amount due to scattering and absorption of laser light in the unrecorded first recording layer 7. Can be recorded. Further, since information can be recorded on the first recording layer 7 and the second recording layer 9 for each zone, the rotation control time of the spindle 25 due to the change of the zone can be minimized.

Further, since the movement of the light spot during recording can be performed within the zone, the movement time can be minimized. Normally, the moving distance of the light spot in the CD size is about 30 to 40 mm, and a cheap moving mechanism requires about 0.2 to 0.3 seconds of moving time.
Therefore, if the zone is set to about 1 mm, a moving time of about 0.01 second is sufficient, so that information is recorded in all the zones of the second recording layer 9 and then information is recorded in the first recording layer 7. In comparison, the moving time of the light spot can be greatly reduced.

If the scattering and absorption of the laser beam due to the recording of the first recording layer 7 are small, FIG.
The recording of information is started from the first recording layer 7 of the zone n + 1 32 without moving the focal position in the zone n + 1 32 shown in FIG. By recording in the, due to zone change,
The operation of the information recording / reproducing apparatus is changed only by controlling the rotation of the spindle 25, and the transfer rate during information recording can be improved.

As described above, when the recording order is arbitrarily changed according to the characteristics of the recording medium, the reproduction can be performed smoothly by recording the recording order in the management area 40 shown in FIG. it can.

[0024]

According to the present invention, in recording on a recording medium having a multilayer structure, the recording information of the recording layer through which the laser beam passes is not destroyed, and the recording information passes through a plurality of recording layers. Since the fluctuation can be suppressed only by a constant light quantity change, highly reliable information recording can be performed. Further, since information can be recorded on the recording layer having a multilayer structure for each zone, the moving time of the light spot can be minimized, and the transfer rate at the time of information recording can be improved.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram showing a focus position detection method for a multilayered recording medium according to an embodiment of the present invention.

FIG. 3 is a view showing an information recording method in a multilayered recording medium according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser, 4 ... Lens, 5 ... Recording medium, 6 ... Substrate, 7
... first recording layer, 8 ... intermediate layer, 9 ... second recording layer, 10 ... protection layer, 22 ... servo drive circuit, 23 ... controller, 2
4 spindle drive circuit, 25 spindle, 31 zone n, 40 management area, 41 zone m.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D090 BB04 BB12 CC01 CC14 DD03 DD05 EE01 FF09 FF34 HH01 5D110 AA14 BB01 BC11

Claims (6)

[Claims] An information recording medium for recording information by irradiating an oscillated laser beam onto an information recording medium to form a recording portion having a physical property different from that of an unrecorded portion of information in a recording area on the information recording medium. A recording method for recording information on a recording medium having a multilayer structure in which a plurality of recording layers in which information is stored is three-dimensionally arranged on a medium, and a recording area in a plane of each recording layer is subdivided. Information is recorded in a subdivided recording area in the plane of each recording layer, and from the state where all the recording areas of each recording layer are recorded, to the subdivided recording area in the plane of the next recording layer. An information recording method for a multi-layer structure recording medium, characterized by recording information and sequentially recording information on a plurality of recording layers arranged three-dimensionally. 2. An information recording method according to claim 1, wherein the information is recorded on a recording medium on which information can be recorded only once. An information recording method for a multi-layer structure recording medium, characterized in that information is recorded in the opposite direction to the information recording layer that is arranged in a plurality. 3. An information recording method according to claim 1, wherein the information is recorded on a recording medium in which the amount of laser light varies greatly due to scattering and absorption by recording the information. An information recording method for a multi-layer structure recording medium, characterized in that information is recorded in a direction opposite to a three-dimensionally arranged information recording layer to which laser light sequentially arrives. 4. The information recording method according to claim 1, wherein the recording medium in which the recording area in the plane is subdivided is M-CLV (Modified).
In an information recording method in which rotation is controlled by a (Constant Linear Velocity) method, information is recorded in a subdivided recording area in the plane of each recording layer, and the recording area of each recording layer is recorded from the state where all recording areas are recorded. A method for recording information in a subdivided recording area in a plane of each recording layer, wherein only the number of rotations of the recording medium is controlled. 5. An information recording method for a multi-layer structure recording medium according to claim 1, wherein the order of recording information is recorded in a predetermined area of the recording medium. 6. The information recording method according to claim 1, wherein the focal position of each recording layer of the multi-layer recording medium is determined before recording information in a predetermined area of the recording medium or an area for managing recording information. An information recording method for a multi-layer structure recording medium, wherein the focus position is detected in advance.