JP2002063723A - Optical disk, recording/reproducing apparatus and recording/reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problem that a substantial reduction of the recording capacity of an optical disk is caused by recording of a synchronizing signal as the reference of rotation control information by wobbling and that address information needs the dedicated area ID of an address bit in the optical disk formed of prepits. SOLUTION: This optical disk 1 provided with spirally formed grooves 2, and a land 3 formed between adjacent grooves 2 and 2 is rotated at a constant linear velocity, and an information signal is recorded or reproduced in one or both of the groove 2 and the land 3 with an optical beam. In this case, each width of the group 2 and the land 3 is roughly constant, only one of the right and left side walls of the group 2 or the land 3 is formed by wobbling at a roughly constant period, and wobbling is formed corresponding to the data bit value of the address information. Thus, the data area and the address information area are commonly used, and a high-density recording/reproducing operation is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc, a recording / reproducing apparatus and a recording / reproducing method, and more particularly to a recordable optical disc having spindle rotation control information and address information recorded by wobbling a pre-groove, and this optical disc. The present invention relates to a recording / reproducing apparatus and a recording / reproducing method for reading out spindle rotation control information and address information from a HDD and recording / reproducing data at high density.

[0002]

2. Description of the Related Art When recording data on an optical disk,
It is necessary to record address information on a disk in advance so that data can be recorded at a predetermined position.
This address information includes a CD-R (compact disk record)
dable), a recordable optical disk that is wobbling-recorded at a predetermined frequency along a groove has an ATIP (Abso) indicating a specific position on the disk.
lute Time In Pregroove), there is absolute time information recorded by frequency-modulating wobbling.

That is, as shown in FIG. 7, a track for recording data is formed in advance as a pre-groove G,
In the optical disc D in which the lands L are formed between the pre-grooves G, the side walls w of the pre-grooves G are wobbled (meander) in accordance with the frequency-modulated address information. In this way, the address information can be read from the wobbling, and data can be recorded at a desired track position of the pre-groove G on the optical disc D.

In the case where address information is recorded by wobbling by frequency modulation as described above, when data is recorded on the track of the pre-groove G, the address information in the wobble signal reproduced from the pre-groove G is accurately recorded. The data can be read, so that data can be recorded at an accurate position based on the address information.

[0005]

However, when the track of the land L is scanned, the wobbling signals of the tracks of the right and left pre-grooves G adjacent to the track of the land L are combined, so that the track of the land L is scanned. It becomes difficult to correctly reproduce address information corresponding to scanning. As a result, rotation control information and address information for rotating the optical disc D cannot be read, and it becomes difficult to record data on the track of the land L.

As one method for solving this problem, Japanese Patent Application Laid-Open No. Hei 9-231580 discloses a method in which a synchronization signal serving as a reference for rotation control information is recorded by wobbling and address information is formed by prepits. In this optical disc, the information recording area is divided into a plurality of zones in the radial direction of the disc, and when the optical disc is rotated at a constant angular velocity, the groove has a predetermined frequency corresponding to each zone in each of the plurality of zones. The wobbles are wobbled in the radial direction, and the spatial frequency of the wobbles is made substantially constant in each zone, so that a wobble of a single frequency can be correctly reproduced even on a land track. By prerecording the address information as a pre-pit at the boundary between the land and the groove, the address information can be obtained from both the land and the groove.

However, according to this method, as shown in an enlarged view of a main part conceptually showing a recording form of a disk in FIG. 8, a recording and reproducing operation is carried out in which a groove G and a land L are wobbled adjacently. A dedicated area ID of address bits in which pre-pits are recorded is required in an area different from the area described above, and the recorded data is divided so that a phase locked loop (PLL) circuit for data reading is easily synchronized. In addition, a VFO (Variable Frequency Oscillator) is required to be inserted after the address bit area (at the beginning of the data), and the recording capacity of the optical disk is substantially reduced. Therefore, the conventional optical disk described above has a drawback that, when information is recorded on both the land L and the groove G, it is necessary to physically separate the address area and the data area, so that high-density recording is difficult. is there.

[0008] The present invention has been made in view of the above points,
An object of the present invention is to provide an optical disk, a recording / reproducing apparatus, and a recording / reproducing method capable of performing high-density recording by using both an address area and a data area when data is recorded on both lands and grooves.

[0009]

In order to achieve the above object, an optical disk according to the present invention comprises a spirally or concentrically formed groove and a land formed between adjacent grooves. In an optical disc that is rotated at a constant linear velocity and records or reproduces an information signal on one or both of the groove and the land by a light beam, each width of the groove and the land is substantially constant, and the width of the groove or the land is It is characterized in that only one of the left and right side walls is wobbled and formed at a substantially constant cycle, and the wobbles are formed corresponding to the value of the data bit of the address information.

According to the present invention, wobbles are formed at a substantially constant period only on one of the right and left side walls of the groove or the land, and the wobbles are formed corresponding to the value of the data bit of the address information. At the time of recording or reproduction of the optical disk, the rotation control of the optical disk can be stabilized based on the address information read from the reproduction wobble signal, and the track position can be accurately read. Further, according to the present invention, the address information area and the data area can be used also in the optical disc which records the information signal in both the groove and the land.

Here, the address information of the wobble is at least address data indicating a sector number or a block number, and the cycle of the address data is substantially constant over the circumference of the disk. Features.

In order to achieve the above object, a recording / reproducing apparatus according to the present invention records an information signal with a laser beam emitted from an optical head while rotating an optical disk having the above-mentioned configuration at a constant linear velocity, or A recording / reproducing apparatus that receives reflected light from an optical disc with an optical head and reproduces an information signal recorded on the optical disc. The recording / reproducing apparatus converts the signal obtained by receiving the reflected light from the optical disc during recording or reproduction into wobble. Detecting means for detecting a corresponding wobbling signal;
Address information reading means for reading address information based on the wobbling signal detected by the detection means;
Rotation control means for controlling the rotation of the optical disc at a constant linear velocity in synchronization with the wobbling signal detected by the detection means, and movement of the optical head in the radial direction of the optical disc based on the address information read by the address information reading means. And a movement control means for controlling the movement.

According to the present invention, an optical disk in which wobbles are formed at a substantially constant period only on one of the right and left side walls of a groove or a land, and the wobbles are formed corresponding to data bit values of address information In this case, the rotation control of the optical disc can be stabilized and the track position can be accurately read based on the address information read from the reproduction wobble signal.

In order to achieve the above object, the recording / reproducing method of the present invention records an information signal with a laser beam emitted from an optical head while rotating an optical disk at a constant linear velocity, or reflects an information signal from the optical disk. A recording / reproducing method for reproducing an information signal recorded on an optical disk by receiving light with an optical head, wherein a wobbling signal corresponding to a wobble is obtained from a signal obtained by receiving reflected light of the optical disk during recording or reproduction. A second step of reading address information based on the detected wobbling signal; a second step of controlling the rotation of the optical disk at a constant linear velocity in synchronization with the wobbling signal; A third method for controlling the movement of the optical head in the radial direction of the optical disk based on the address information read in step (3).
And a step of:

According to the present invention, an optical disk in which wobbles are formed at a substantially constant period only on one of the right and left side walls of a groove or a land, and the wobbles are formed corresponding to the value of data bits of address information In this case, the rotation control of the optical disc can be stabilized and the track position can be accurately read based on the address information read from the reproduction wobble signal.

[0016]

Next, an embodiment of the present invention will be described with reference to the drawings. 1A and 1B are schematic schematic plan views of an embodiment of an optical disc according to the present invention,
The main part enlarged schematic diagram is shown. As shown in FIG. 1A, a groove (guide groove) 2, which is a track for recording data, is formed in advance on the optical disc 1 in a spiral manner from the inner circumference to the outer circumference. The width of the groove 2 is constant, and the width of the land (between the guide grooves) 3 between the grooves 2 is also constant. The direction of the spiral may be formed from the outer periphery to the inner periphery, and may be concentric rather than spiral.

As a recording method used for an optical disk having such a configuration, it is possible to use the groove 2 and the land 3 together as a track on which data is to be recorded, and to record data on both the groove 2 and the land 3. is there.
Alternatively, data can be recorded using only the groove 2 as a recording track.

Further, as shown in FIG. 1B, which is a schematic enlarged view of a portion surrounded by a broken line I in FIG. 1A, a groove pitch (land pitch) GP is, for example, about 0.8 μm. , One side wall of the groove 2 (land 3) is wobbled by a small amount in the radial direction. In FIG.
By forming one side wall of the groove 2 by wobbling, one side wall of the land 3 is also formed to be wobbled. The wobbling amplitude A of the groove 2 (land 3) is, for example, about 0.01 μm, and is preferably sufficiently smaller than the groove pitch (land pitch) so as not to affect the original tracking. Since the physical length of one cycle of such wobbling is formed constant, the repetition frequency of the wobble signal becomes a constant frequency when the optical disc 1 is rotated at a constant linear velocity.

The spatial frequency (the number of times of wobbling per unit line length) is set to be substantially constant. The spatial frequencies of the wobbles are made equal from the innermost circumference to the outermost circumference. This spatial frequency is preferably set to a frequency sufficiently higher than the tracking servo band (generally several kHz) when actually rotating at the recording rotation speed so as not to affect the original tracking. .

FIG. 2 is a sectional perspective view of an embodiment of the optical disk 1. As shown in FIG. 2, in the groove 2 on the optical disc 1, one side wall of the groove track is wobbled in one cycle (for example, a period of 25 μm) of the synchronization signal, one of the left and right side walls is not wobbled, and the other is an address. The configuration is such that the presence or absence of meandering is determined according to the data bits of the information.

For example, in the section where the data bit of the address information is "1" as in the disk track shown in FIG. 6A, one of the right and left side walls of the track is formed so as not to meander for one period of wobbling. The section where the data bit of the address information is “0” is formed in a meandering manner. That is, wobbling is formed with a change amount corresponding to the address information. The address information is an address indicating a sector number or a block number.
The period of the address information is formed substantially constant over the circumferential direction (track direction) of the optical disc 1.

By forming the groove 2 as described above, the wobbling is detected stably even when scanning the land track and also on the land 3 in the same manner as when scanning the groove 2. Can be obtained stably as in the case of the groove 2.

FIG. 3 shows an optical disk 1 having a pregroove.
1 is a configuration diagram of an example of an optical disk master manufacturing apparatus for manufacturing a master. In the figure, a master clock is frequency-divided by a frequency divider 11 and supplied to a modulation circuit 12 together with address information as a clock of a fixed period. Modulation circuit 12
Determines the presence or absence of a wobble according to modulated data bits (address data bits represented by “1” and “0”) of address information, and outputs an address wobbling signal (address information wobble signal).

That is, the modulation circuit 12 is, for example, as shown in FIG.
When the address bit data shown in (A) is "1", the clock is not output for one cycle, and when the address bit data is "0", the clock is output, so that the address data bit is not output. An address wobbling signal corresponding to the value is output. The address wobbling signal is shaped into a sine wave by a low-pass filter (LPF) 13 to have a waveform as shown in FIG. 4B, and then amplified to a required level by an amplifier 14 to be deflected by an optical deflector 15.
And drives it.

The laser light from a light source (not shown) enters the optical deflector 15 with the optical path changed by a half mirror 16 and a total reflection mirror 17, and is deflected according to an address wobbling signal. The laser light deflected by the optical deflector 15 is reflected by the half mirror 19, passes through the half mirror 16 and the total reflection mirror 18, and enters the objective lens 20 together with the laser light from the light source transmitted through the half mirror 19. The two laser beams incident on the objective lens 20 are disposed adjacent to each other in the radial direction on the master 21 so as to form the left and right side walls of the groove 2 and expose the master 21. Spindle motor 2
Numeral 2 is for rotating the master 21 at a predetermined speed.

The master 21 is developed, a stamper is created from the master 21, and a number of replica optical disks 1 are formed from the stamper. As a result, the optical disc 1 on which the pregroove 2 is formed corresponding to the above-mentioned address signal (wobble signal) is obtained. One side wall of the pre-groove 2 of the optical disk 1 is formed (wobbled) in accordance with the address signal.

FIG. 5 is a block diagram showing an embodiment of the recording / reproducing apparatus according to the present invention. Referring to FIG. 1, an optical disk 1 is an optical disk prepared from the master 21. As described with reference to FIGS. 1 to 4, tracks are formed in a spiral or concentric manner with substantially constant groove width and groove width. One of the right and left side walls of the track is wobbled, and the wobble is formed so as to be reproduced at a substantially constant frequency from the inner circumference to the outer circumference when the optical disc 1 is rotated at a constant linear velocity. The wobble is formed corresponding to the data bit of the address information.

This optical disk 1 has a spindle motor 2
5, the optical head 26 is rotated at a constant linear velocity.
From the laser beam. At the time of recording, the recording data obtained by performing predetermined signal processing such as modulation by the recording / reproducing circuit 27 is input to the optical head 26, and the optical head 26 modulates a laser beam applied to the optical disk 26 to record the recording data. Also,
At the time of reproduction, the optical head 26 receives the reflected light of the laser light applied to the optical disc 1 and performs photoelectric conversion, and supplies the obtained reproduced RF signal to the recording / reproducing circuit 27 for demodulation. The reproduction data thus obtained is output to the outside.

The wobble detection circuit 28 receives an RF signal output from the optical head 26 by receiving the reflected light from the optical disk 1 and inputting and outputting the wobble signal in both cases of recording and reproduction. By making use of the fact that the data and the frequency band are significantly different, FIG.
A wobble signal as shown in FIG. Here, in a section where neither of the right and left side walls of the track to be reproduced shown in FIG. 6A has meandering, the amplitude of the wobble signal is smaller than that of a place where one of the side walls meanders. This is a section in which the address data bits in the section having no wobble signal amplitude correspond to “1”.

This burst-like wobble signal (synchronous signal wobble) is applied to a phase locked loop (PLL: Phase Locked L).
oop) 29, where it is converted into a synchronization signal as shown in FIG. 6C, which is phase-synchronized with the wobble signal, and then sent to the motor control circuit 30 of the spindle motor 25, where the spindle motor 25 is driven by a CLV (Constant). Linear Veloci
(ty: constant linear velocity) is used as a reference signal for controlling the rotation.

On the other hand, the wobble signal output from the wobble detection circuit 28 is also supplied to an AM (Amplitude Modulation) demodulation circuit 31 together with the synchronization signal output from the PLL 29. The AM demodulation circuit 31 demodulates the amplitude-modulated and reproduced wobble signal by envelope detection or synchronous detection using a synchronous signal. As a result, a demodulated signal as shown in FIG. 6D is extracted from the AM demodulation circuit 31 and supplied to the address reading circuit 32, where the L level of the demodulated signal is "0" and the H level is "1". Play and
Read address data bits, which are address information.

The feed control circuit 33 includes the address reading circuit 3
2 and the optical head 2 from the recording / reproducing circuit 27
6 receives scanning address information of the optical disk 1 which is currently performing recording / reproduction scanning, and supplies a control signal for controlling the rotation of the feed motor 34 such as forward rotation, reverse rotation, and stop according to the comparison result. The optical head 26 is provided with the feed motor 3
In accordance with the rotation direction of the optical disc 4, the transport of the optical disc 1 is controlled in the inner circumferential direction or the outer circumferential direction. Thereby, the recording / reproducing circuit 2
7 detects and confirms the exact position of the sector where the optical head 26 is currently performing recording / reproduction scanning, and checks the optical head 26 for recording data.
And outputs the demodulated reproduced data to an external device.

As described above, according to the present embodiment, the wobble signal is reproduced in the land 3 and the groove 2 similarly, so that a stable synchronization signal and address signal can be always obtained. Therefore, in this embodiment, when data is recorded in both the land 3 and the groove 2, the address area and the data area can be used in common, and high-density recording can be realized.

[0034]

As described above, according to the present invention,
Wobble is formed at a substantially constant period on only one of the left and right side walls of the groove or land, and the wobble is recorded or reproduced on or from an optical disk formed according to the value of the data bit of the address information. As a result, the rotation control of the optical disk can be stabilized based on the address information read from the reproduction wobble signal, and the track position can be read accurately, so that the information signal can be recorded at a high density and the reproduction can be performed. And the relative linear velocity between the optical disc and the laser beam is constant (CL
V) The rotation control can be performed accurately.

Further, according to the present invention, the information signal can be recorded and reproduced at a high density even in an optical disk in which the information signal is recorded in both the groove and the land, since the address information area and the data area can be used in common.

Further, according to the recording / reproducing apparatus and the recording / reproducing method of the present invention, data can be stably recorded on the optical disk at a high density, while data recorded on the optical disc at a high density can be reproduced stably. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of an optical disc according to an embodiment of the present invention.

FIG. 2 is a sectional perspective view of an embodiment of the optical disk of the present invention.

FIG. 3 is a configuration diagram of an example of a master manufacturing apparatus that creates an optical disc according to the present invention.

FIG. 4 is a signal waveform diagram for explaining the operation of the optical deflector in FIG. 3;

FIG. 5 is a block diagram of an embodiment of the recording / reproducing apparatus of the present invention.

FIG. 6 is a diagram showing a relationship between a signal waveform of a main part in FIG. 5 and a track.

FIG. 7 is an enlarged conceptual diagram of a main part of an example of a conventional optical disk.

FIG. 8 is an enlarged conceptual diagram of a main part of another example of the conventional optical disc.

[Explanation of symbols]

 Reference Signs List 1 optical disk 2 groove 3 land 11 frequency divider 12 modulation circuit 15 optical deflector 16, 19 half mirror 17, 18 total reflection mirror 20 objective lens 21 master disk 25 spindle motor 26 optical head 27 recording / reproducing circuit 28 wobble detecting circuit 29 phase synchronization Loop (PLL) 30 Motor control circuit 31 AM demodulation circuit 32 Address reading circuit 33 Feed control circuit 34 Feed motor

Claims (4)

[Claims] A helical or concentric groove; and a land formed between the adjacent grooves. The groove is rotated at a constant linear velocity, and one of the groove and the land is formed. In both cases, in an optical disc on which an information signal is recorded or reproduced by a light beam, each width of the groove and the land is substantially constant, and only one of the left and right side walls of the groove or the land is wobbled at a substantially constant cycle. An optical disk, wherein the optical disk is formed and the wobble is formed corresponding to a value of a data bit of address information. 2. The wobble address information is address data indicating at least a sector number or a block number, and the cycle of the address data is recorded substantially constant in the circumferential direction of the disk. The optical disc according to claim 1, wherein 3. An information signal is recorded by a laser beam emitted from an optical head while the optical disk according to claim 1 is rotated at a constant linear velocity, or reflected light from the optical disk is received by the optical head. A recording / reproducing apparatus for reproducing an information signal recorded on an optical disk, comprising: detecting means for detecting a wobbling signal corresponding to the wobble from a signal obtained by receiving reflected light from the optical disk during recording or reproduction. Address information reading means for reading the address information based on the wobbling signal detected by the detection means; and rotation control of the optical disk at a constant linear velocity in synchronization with the wobbling signal detected by the detection means. Based on the address information read by the address information reading means, Recording and reproducing apparatus characterized in that it comprises a movement control means for controlling the movement of the radial direction of the optical disc of the serial optical head. 4. An information signal is recorded by a laser beam emitted from an optical head while the optical disk according to claim 1 is rotated at a constant linear velocity, or reflected light from the optical disk is received by the optical head. A recording / reproducing method for reproducing an information signal recorded on an optical disk, comprising: detecting a wobbling signal corresponding to the wobble from a signal obtained by receiving reflected light of the optical disk during recording or reproduction; A second step of reading the address information based on the detected wobbling signal; and controlling the rotation of the optical disk at a constant linear velocity in synchronization with the wobbling signal. A third step of controlling movement of the optical head in the radial direction of the optical disk based on the read address information;
Recording and reproducing method.