JP2000195106A - Optical disk, producing device of optical disk, production of optical disk, optical, disk recording and reproducing device and recording and reproducing method of optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new optical disk having a ROM region and a RAM region in one track of a same disk, and to provide a producing device of an optical disk, producing method, recording and reproducing device and recording and reproducing method. SOLUTION: The partial ROM disk has grooves 270 in which first ROM signals 271 recorded on the side walls of the inner circumference are read out with a light beam which irradiates the center or near the center of the side walls of the inner circumference and in which second ROM signals 271 recorded on the side walls of the outer circumference are read out with a light beam which irradiates the center or near the center of the side walls of the outer circumference. Then a recording and reproducing film is applied to form MO mark lines 273 for recording and reproducing RAM data on the grooves 270 and/or lands by a light beam which irradiates the center or near the center of the grooves 270 and/or lands. Thus, high recording density is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical disk, for example, which has both a recordable area (RAM area) and a read-only area (ROM area). Further, the present invention can be applied, for example, as an optical disk manufacturing apparatus and a manufacturing method for manufacturing a magneto-optical disk having both a RAM area and a ROM area. Further, the present invention relates to a magneto-optical disk recording / reproducing apparatus having both a RAM area and a ROM area,
The present invention can also be applied as a recording / reproducing method for a magneto-optical disk having both the AM area and the ROM area.

[0002]

2. Description of the Related Art In recent years, optical disks that have rapidly progressed include a read-only ROM represented by a compact disk (CD) and a digital video disk (DVD).
There is a disk. Further, as an optical disk on which a user can record data, a CD-R disk, a CD-RW disk, a PD disk, a magneto-optical (MO) disk, a DVD
-A RAM disk or the like has been commercialized.

As described above, various types of optical discs on which a user can record arbitrary data later have been realized.
Each is called by a different name. In the present invention, in order to avoid complication, a read-only optical disk is referred to as a ROM disk, and a disk on which a user can record information later is referred to as a RAM disk regardless of the method.

[0004] Further, a partial ROM disk has been proposed which has two areas, namely, a read-only ROM disk area and a recordable / reproducible RAM disk area while being a single disk.

For example, Japanese Patent Laid-Open Publication No. 8-273161 published on Oct. 18, 1996 discloses a technique for recording a reference pattern only in a RAM area in an optical disc having a ROM area and a RAM area. Have been.

More recently, such partial ROMs
Development is also underway to prevent piracy using optical disks. For example, in a published patent publication published on October 18, 1996 (JP-A-8-273164), R
An idea is described in which the physical characteristics of an OM type optical disk are extracted, encrypted, and recorded on a RAM type optical disk, thereby preventing use of an illegally duplicated optical disk.

Japanese Patent Application Laid-Open No. Hei 6-309673 discloses a spiral or a spiral type in which a CLV rotation system and a CAV rotation system can be used, and stable tracking control can be performed even if the track density is reduced. In an optical disc having a concentric guide groove, one edge of the guide groove is displaced in the groove width direction according to a first frequency modulation signal for CLV rotation, and the other edge is CAV.
An optical disc and a recording / reproducing method that can be used in both the CLV rotation control and the CAV rotation control by displacing in the groove width direction according to a second frequency modulation signal for rotation, and a recording / reproducing method thereof are disclosed.

[0008]

However, the information in the ROM and RAM recorded by these methods is recorded according to the same principle as that of an optical disk known hitherto. For this reason, it was necessary to physically separate the ROM area and the RAM area in some way.

For example, in an example disclosed in Japanese Patent Application Laid-Open No. 8-273161, a ROM area and a RAM area are recorded in separate radius areas. In addition, Heisei 9
Patent Publication (JP-A-9-1802) published on July 11, 2008
No. 48) discloses an optical disc technology in which a ROM area and a RAM area are configured as separate layers.

[0010] The partial ROM disk which has been proposed so far has the RAM area and the ROM area separately recorded in different places. In these systems, the ROM and the RAM are separated from each other, so that a spaceless portion (overhead) is generated, and as a result, there is a problem that the recording capacity of the entire optical disk cannot be increased much.

In the conventional method in which the ROM and RAM areas are clearly separated and recorded, even a person who creates a so-called pirated copy by illegal copying can clearly distinguish between the ROM and RAM areas. Therefore, there was a problem that the creation of a pirated version was easy.

In the optical disk and the recording / reproducing method described in JP-A-6-309673, address information for CLV rotation is simply recorded on one edge of the guide groove.
Since address information for CAV rotation is recorded on the other edge, information data can be recorded only on a land or a groove. Since recording and reproduction of both edges cannot be performed simultaneously, high-density recording can be performed. There was a disadvantage that you could not do.

Accordingly, an object of the present invention is to realize a new partial ROM disk in which a ROM area and a RAM area are mixed in the same track in the same disk.
At the same time, the present invention also proposes a manufacturing apparatus and a manufacturing method for manufacturing such a partial ROM disk. Further, according to the present invention, RO
A recording / reproducing apparatus and a recording / reproducing method for performing recording / reproducing on an optical disk in which an M area and a RAM area are mixed are also proposed.

As described above, a new partial ROM disk in which the ROM area and the RAM area are mixed in the same track in the same disk has a reduced overhead as compared with the conventional partial ROM, so that the recording capacity is increased. Further, it has a feature that it is extremely difficult to create a pirated disk as compared with a conventional partial ROM.

The applicant of the present application has filed Japanese Patent Application No. 10-273.
No. 785, a first recording signal that changes according to first input data and a second recording signal that changes according to second input data are used to reduce bit errors in reproduced data and improve recording density. Generating a second recording signal;
The emission direction of the first light beam is displaced in accordance with the first recording signal to displace the inner peripheral side wall surface of the groove, and the emission direction of the second light beam is changed in response to the second recording signal. An optical disk device or an optical disk recording method for displacing the outer peripheral side wall surface of the groove by displacing the groove has been proposed.

Also, the applicant of the present application has filed Japanese Patent Application No. 10-291.
In No. 117, for the purpose of evaluating the quality of an optical disk without being affected by recording conditions, a laser beam is condensed by an optical pickup and irradiated as an optical spot on an optical disk having grooves formed in a spiral shape. In an optical disk evaluation device that converts the light reflected or diffracted by an optical disk into an electric signal by a photodetector and evaluates the quality of the optical disk based on the obtained electric signal, the center of the spot controlled by the optical pickup is positioned on the groove wall. An optical disk evaluation device that controls so as to pass above is proposed.

[0017]

SUMMARY OF THE INVENTION The present invention provides a partial R
In an OM disk, a first beam recorded on the inner peripheral wall surface by a light beam irradiating substantially the center on the inner peripheral wall surface.
And a groove for reading a second signal recorded on the outer peripheral side wall surface by a light beam irradiating substantially the center on the outer peripheral side wall surface, and substantially on the groove or / and land. An optical disk provided with a recording / reproducing film for performing recording / reproducing on the groove or / and the land by a light beam irradiating the center. Therefore,
Since the ROM data recorded on the optical disc of the present invention is recorded as independent information on both walls of the groove, it is possible to realize a higher recording density than the conventional method. Further, it is possible to record the data of the RAM between the groove walls on which the data of the ROM is recorded. Therefore, the optical disc according to the present invention can realize a recording density much higher than that of the conventional optical disc.

The optical disk manufacturing apparatus further comprises: a master disk forming means for forming a grooved disk master by focusing and irradiating a laser beam onto an optical recording medium by optical means; And a recording film forming means for forming an additional recordable reflective film on the duplicate disk, and the master disc generating means generates a first recording signal that changes in accordance with the input digital information. First recording signal generation means, second recording signal generation means for generating a second recording signal that changes according to the input digital information, and emission direction of the first light beam according to the first recording signal The first light control means for displacing the inner peripheral side wall surface of the groove, and displacing the emission direction of the second light beam according to the second recording signal, It is constructed optical disc manufacturing apparatus in the second light control means for displacing the outer peripheral side wall of Lube.

Therefore, in the optical disk manufactured by the optical disk manufacturing apparatus of the present invention, since the ROM data is recorded as independent information on both walls of the groove, it is possible to realize a higher recording density than the conventional method. Becomes
Further, it is possible to record the data of the RAM between the groove walls on which the data of the ROM is recorded. Therefore, the optical disc according to the present invention can realize a recording density much higher than that of the conventional optical disc.

Further, the method of manufacturing an optical disk according to the present invention comprises the steps of: forming a master disk for forming a grooved disk master by irradiating a laser beam onto an optical recording medium by optical means; Creating a duplicate disk medium from a duplicate disk medium from the
A recording film forming step of forming a reflective film that can be additionally recorded on the duplicate disk medium is provided,
A first recording signal generating step for generating a first recording signal that changes according to the digital information; a second recording signal generating step for generating a second recording signal that changes according to the digital information; Displacing the emission direction of the first light beam according to the signal, the first light control step of displacing the inner peripheral side wall surface of the groove, and changing the emission direction of the second light beam according to the second recording signal. Displace,
And a second light control step of displacing the outer peripheral side wall surface of the groove.

Therefore, in the optical disk manufactured by the optical disk manufacturing method of the present invention, since the ROM data is recorded as independent information on both walls of the groove, it is possible to realize a higher recording density than the conventional method. Becomes
Further, it is possible to record the data of the RAM between the groove walls on which the data of the ROM is recorded. Therefore, the optical disc according to the present invention can realize a recording density much higher than that of the conventional optical disc.

Further, the optical disk recording / reproducing apparatus of the present invention has a tracking means for controlling the center position of a light spot formed on the information recording surface of the optical disk by the light beam, and detects the light beam reflected by the optical disk. A light receiving means is provided, and when reading the ROM area, the light spot is controlled so as to coincide with the meandering center of one wall surface of the groove. In addition, when recording / reproducing in the RAM area, the light beam condensing position is controlled so that the light spot coincides with the center of the groove or land.

Therefore, in the optical disk recording / reproducing apparatus of the present invention, it is possible to stably reproduce the information of the ROM recorded as independent information on both walls of the groove. As a result, it is possible to realize a higher recording density than the conventional method. Further, when recording / reproducing RAM data, it is possible to record / reproduce RAM data by moving the center of a spot between groove walls. Thus, the optical disk recording / reproducing apparatus according to the present invention can realize a partial ROM disk having a recording density much higher than that of the conventional one.

Also, the recording / reproducing method for an optical disk according to the present invention comprises a tracking step for controlling the center position of a light spot and a light receiving step for detecting a light beam reflected by the optical disk. When reading the ROM area, the light beam condensing position is controlled so that the light spot coincides with the meandering center of one wall surface of the groove recorded on the optical disk. The information in the ROM recorded as independent information can be reproduced stably. As a result, it is possible to realize a higher recording density than the conventional method. Further, when recording and reproducing data in the RAM, it is possible to record and reproduce data in the RAM by moving the spot to the center of the groove or the center of the land. In this way, by applying the optical disk recording / reproducing method according to the present invention, it is possible to realize a partial ROM disk having a much higher recording density than the conventional one.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, a partial ROM disk manufacturing apparatus 1 according to an embodiment of the present invention will be described. In FIG. 1, a digital tape recorder 2
Audio information SA, SB recorded on 1A and 21B
Is supplied to the master disc exposure apparatus 10. The master disc exposure apparatus 10 receives the input audio information SA,
A modulation signal is created according to the SB, the laser beam is modulated according to the completed modulation signal, and exposure is performed on the master disk 17 such that both sides of the groove wall meander independently according to the modulation signal.

The exposed master disk 17 is subjected to a developing process and a plating process by a developing and plating device 22, and a stamper 23 is completed. Further, the stamper 23 is loaded into an injection molding device 24, and a large number of disk substrates 25 formed of a plastic material such as polycarbonate are duplicated. A spiral groove is formed on the disk substrate 25 thus created. The inner wall surface and the outer wall surface of the groove thus formed meander according to the audio information SA and SB, respectively, so that the audio information SA and SB are recorded.

The disk substrate 25 thus obtained
A reflective film having magneto-optical characteristics is formed by the reflective film forming device 26, and a partial ROM disk 27 is completed. As the reflection film forming apparatus 26, an apparatus generally called a sputtering apparatus can be used.

On the partial ROM disk 27 completed as described above, audio information SA and SB are recorded as a meandering groove wall. When the signal recording surface of such a disc is photographed with an electron beam microscope or the like,
For example, as shown in FIG. 2A, the left and right walls of the groove 270 change independently of each other, so that a ROM signal 271 is recorded, thereby recording audio information SA and SB. The user can reproduce information recorded as a ROM signal by mounting such a partial ROM disk 27 in the optical disk recording / reproducing apparatus 3. In the configuration shown in FIG. 1, the computer 28 accesses the optical disk recording / reproducing device 3 to read out the information recorded on the partial ROM disk 27, and reproduces the audio information SA and SB via a speaker built in the computer 28. It is possible to listen.

The partial ROM disk 27 thus completed may be inserted into the optical disk recording / reproducing device 3 connected to the computer 28 for additionally recording / reproducing information. At this time, the optical disk recording / reproducing device 3 receives the instruction from the computer 28 and stores the additional user data in the partial ROM disk 2
Additional recording on groove 7 or land. FIG. 2B schematically shows the state of the partial ROM disk 27 'additionally recorded on the information recorded by the ROM signal 271 in this manner. In this figure, an additionally recorded MO (magneto-magnetic) mark row 27
3 is between the grooves 270 (land 2
72). Of course, not only the land 272 can be used, but also the MO mark row 272 can be recorded only in the groove 270 or in both the land 272 and the groove 270.

In this embodiment, as shown in FIG. 2B, an MO mark row 273 is recorded in the center of the groove 270 or the land 272, and the ROM signal 27 is recorded.
1 is recorded as meandering of the wall of the groove 270. As described above, since the information of the ROM and the RAM is mixed in substantially the same area, the overhead is reduced and the recording density can be increased. Furthermore, in the partial ROM system proposed so far,
The areas of the ROM and the RAM are set to different radii.
Therefore, the ROM area is copied in the ROM area,
By copying the AM area as a RAM area, an illegal copy (pirated version) can be created relatively easily. In contrast, in the present invention, the ROM
And RAM are recorded in almost the same radius area. This makes it more difficult to create pirated copies than conventional ones.

FIG. 3 is a block diagram showing a master disk exposure apparatus 10 according to an embodiment of the present invention. The disk master exposure apparatus 10 records digital data SA and SB output from the digital tape recorder 21A and the digital tape recorder 21B by exposing the disk master 17 to light.

In the master disc exposure apparatus 10, a spindle motor 18 drives the master disc 17 to rotate.
The FG signal generation circuit held at the bottom outputs an FG signal FG whose signal level rises at every predetermined rotation angle. The spindle servo circuit 19 drives the spindle motor 18 in accordance with the exposure position of the disk master 17 so that the frequency of the FG signal FG becomes a predetermined frequency, so that the disk master 17 has a predetermined rotation speed. Is driven to rotate.

The recording laser 15 is constituted by a gas laser or the like and emits a laser beam L0 for exposing the master disk. The optical modulator 14 is an AOM (Acoustic Optical M) composed of an electroacoustic optical element or the like.
and modulates the intensity of the laser beam L0 according to the output of the synchronous pattern generation circuit 13. The laser beam L1 into which the synchronization pattern has been inserted in this manner.
Is split by the beam splitter 71 into two light beams. Of the light beams split by the beam splitter 71, the light beam that travels in the downward direction becomes the light beam L2A that travels from left to right in the figure by the mirror 72 and enters the optical modulator 16A. The optical modulator 16A is an AOD (Acoustic Optical) composed of an electroacoustic optical element or the like.
Deflector, which changes the emission direction of the laser beam L2A according to the modulation signal Vp,
Output as 3A. The light beam L2B that has passed through the beam splitter 71 is input to the optical modulator 16B.
The optical modulator 16B is an AOD (Acoustic Optical Defl) configured by an electroacoustic optical element or the like.
and changes the emission direction of the laser beam L2B according to the modulation signal Vo and outputs the laser beam L2B as a laser beam L3B.

The laser beams L3A and L3B obtained in this manner have their optical paths bent by a mirror (not shown) and travel toward the master disk 17, and the objective lens 73
Thus, the light is condensed on the master disk 17. The mirror and the objective lens 73 are sequentially moved in the outer circumferential direction of the disk master 17 by a thread mechanism (not shown) in synchronization with the rotation of the disk master 17, whereby the exposure positions of the laser beams L3A and L3B are sequentially set on the disk master 17.
Is displaced in the outer circumferential direction.

Thus, the disk master exposure apparatus 10
With the disk master 17 being rotated, a groove is formed in a spiral by moving the mirror and the objective lens 73, and the modulation signal Vo and the modulation signal Vp are formed in the groove.
Exposure corresponding to these two signals is performed.

The change in the traveling direction of the laser beam L3A is recorded as a positional displacement of a spot focused on the disk master 17 by the effect of the objective lens 73. Similarly,
The change in the traveling direction of the laser beam L3B is also caused by the disc master 17
It is recorded as the displacement of the spot focused above.

The traveling directions of the laser light L3A and the laser light L3B are slightly offset in advance. This state is shown in FIGS. 4A and 4B. As shown in FIG. 4A, the laser beam L3A enters the objective lens 73 at a slight angle. As a result, the focal position of the laser beam L3A is centered on a position shifted to the right by about 0.1 μm from the focal position F of the objective lens 73. When the traveling direction of the laser beam L3A is modulated by the optical modulator 16A, the focal position of the laser beam L3A changes right and left around the position shown in FIG. FIG. 4B shows how the laser beam L3B is incident on the objective lens 73 at a slight angle. As a result, the focal position of the laser beam L3B changes about the position shifted to the left by about 0.1 micron from the focal position F of the objective lens 73. Also in this case, when the modulation by the optical modulator 16B is performed, the position where the spot is formed further moves left and right around the position shown in the figure.

As a result, the laser light L3A and the laser light L
The average spacing of spots by 3B is
7 is shifted by about 0.2 micron. Referring to FIG. 5, two laser beams L3A and L3B whose center positions are slightly shifted in this way are exposed while changing their positions. As a result, a groove (groove) 170 is recorded on the disk master 17, and the position of the wall of the groove 170 is determined by the laser light L 3.
It is displaced by the positions of A and the spots 173 and 174 of the laser beam L3B. Since the positions of the spots 173 and 174 of the laser light L3A and the laser light L3B are determined by the two modulation signals Vp and Vo, respectively, the information according to the two modulation signals Vp and Vo eventually becomes the position displacement of the wall of the groove 170. Be recorded. FIG. 5 schematically shows a state of the groove 170 in which the two groove walls 1 (171) and 2 (172) are displaced by the independent modulation signals Vp and Vo, respectively. In this figure,
The spot 1 by the laser beam L3A is generated by the modulation signal Vp.
The position of 73 is vertically displaced. This allows
The position of the upper groove wall (groove wall 1 (171)) is modulated. Further, the modulation signal Vo causes the laser light L3
The position of the spot 174 by B is displaced in the vertical direction,
The position of the lower groove wall (groove wall 2 (172)) is modulated.

As described above, in this embodiment, the modulation signal having an analog value such as Vo or Vp is recorded as the displacement of the groove wall. Recording is realized as a signal.

Error correction code generation circuit (ECC) 11A
Receives the digital data SA output from the digital tape recorder 21A, adds an error correction code, and performs an interleaving process to output 8-bit digital signals b0, b1,... B7. Similarly, an error correction code generation circuit (ECC) 11B receives the digital data SB output from the digital tape recorder 21B, adds an error correction code, and performs an interleave process to perform an 8-bit digital signal b8, b9,. Output as In this way, by adding an error correction code to the two information sources to be superimposed and recorded, correct information can be read even if there is a defect on the disk.

The timing generator (TG) 12
Various time reference signals for controlling the timing of the entire disc master exposure apparatus 10 are generated and supplied to various parts of the apparatus. Since it is not practical to illustrate all of these, only the BCLK and SLCT signals are shown in FIG. The BCLK signal is output from the error correction code generation circuits (ECC) 11A and 11B at predetermined intervals at 8-bit digital signals b0, b1,.
9,... B15 are clock signals that change from logic 0 to 1 every time b15 is obtained. By knowing the change of the BCLK signal, the modulation circuits 4A and 4B can know that the 8-bit digital signals b0, b1,... B7 and b8, b9,.

The SLCT signal is a signal which changes from logic 0 to 1 every time data for a predetermined time is recorded on the master disk 17. In accordance with a change in the SLCT signal, a synchronization pattern periodically obtained from the synchronization pattern generating circuit 13 is recorded by modulating the intensity of the laser light L0 by the optical modulator 14. Synchronous pattern generation circuit 13
Then, a pattern for synchronization required at the time of reproduction, address information, servo information necessary for access, and the like are generated. By inserting such a synchronization pattern, it becomes possible to easily synchronize the reproduced signal from the generated disc by an easy method, and it is possible to acquire information of a target track by using address information and the like. Becomes

The modulation circuit 4A outputs the digital signals b0, b
A modulated signal Vm is created in accordance with the BCLK signal and 1,... B7. As described later, the modulation signal Vm thus created has an analog waveform. Modulation circuit 4B
Is configured in the same manner as the modulation circuit 4A, and the digital signal b
, B9,... B15 and the BCLK signal, and the modulation signal V
Create n. Further, the modulation signal Vn created in this manner also has an analog waveform. Modulation signal Vm
Is corrected by the characteristic correction circuit 5A, the signal characteristic specific to the push-pull signal in the tangential direction is corrected, and the nonlinear characteristic of the optical modulator 16A and the like is corrected, and then output as the modulation signal Vp. Similarly, the modulation signal Vn is corrected as a modulation signal Vo after the characteristic characteristic of the push-pull signal in the tangential direction is corrected by the characteristic correction circuit 5B, and the nonlinear characteristic of the optical modulator 16B and the like is corrected. Is output. The corrected modulation signals Vp and Vo are optically modulated by the optical modulators 16A and 16B and recorded on the master disk 17 as displacement of the groove wall.

FIG. 6 is a block diagram showing a configuration of the modulation circuit 4A. In the figure, digital signals b0, b1,..., B7 input to a modulation circuit 4A are input to eight level conversion circuits 49A to 49H, and have eight polarities having amplitudes of either +1 or -1. The signals p0, p1,.
Converted to p7. These eight level conversion circuits 49A
To 49H each include a D flip-flop, an adder circuit, and an amplitude adjustment circuit, all of which have the same configuration. Here, the configuration of the level conversion circuit 49A is shown in FIG. 7 as an example.

In FIG. 7, the input digital signal b0 is first latched by the D flip-flop 490 at the transition point of the BCLK signal from the timing generator 12. Therefore, the output of the D flip-flop 490 is configured to be held at a constant value until a new digital signal b0 is obtained. The D flip-flop 490 normally has a TTL (Tra
nsistor Transistor Logic)
The output Vs is a digital signal having a voltage of about 0 V (volt) or +4 V. The adder 491 performs an addition operation on the output Vs of the D flip-flop 490 and the output of the fixed voltage generator 492, and outputs the result to the amplitude adjustment circuit 493. Since the output of the fixed voltage generator 492 is always −2 V, the output voltage of the adder 491 is Vs +
In the case of 4V, it becomes + 2V. When Vs is 0 V, a voltage of −2 V is obtained at the output of the adder 491.

In the amplitude adjustment circuit 493, the coefficient is set to .0.
5, the polarity signal p0, which is the output of this circuit, becomes -1 V when Vs is 0 V (when b0 is logic 0), and Vs is +4 V (b0
Is Logic 1), the output is + 1V. In this way, a positive or negative 1V polarity signal p0 is obtained at the output of the level conversion circuit 49A. Level conversion circuit 49
8 input digital signals b0, b1,.
, And the same conversion is performed, and eight polarity signals p0, p1,.
Is obtained.

In FIG. 6, reference numerals 41A to 41D denote oscillators for oscillating four types of sine waves. In this embodiment,
The oscillation frequency f2 of the oscillator 41B is twice as large as the oscillation frequency f1 of the oscillator 41A. Further, the oscillation frequency f3 of the oscillator 41C is three times f1.
The oscillation frequency f4 of the oscillator 41D is four times as large as f1. Outputs of these four oscillators 41A to 41D are respectively + 45 ° phase shift circuits 42A and 42B,
42C, 42D, and -45 ° phase shift circuit 43A,
43B, 43C and 43D.

The output of the oscillator 41A is connected to a + 45 ° phase shift circuit 42A and a −45 ° phase shift circuit 43A. Among them, the configuration of the + 45 ° phase shift circuit 42A is as shown in FIG. In this figure, an input signal Vin passes through a low-pass filter including a resistor R42A and a capacitor C42A. The values of the resistor R42A and the capacitor C42A are determined so as to satisfy Equation 1 with respect to the oscillation frequency f1 of the oscillator 41A.

[0050]

F1 = 1 ÷ (2π · R42A · C42A)

By passing through such a low-pass filter, the signal of frequency f1 is subjected to a 45 ° phase shift. However, at the same time as the phase shift, the amplitude also drops by about 3 dB. Therefore, in the circuit shown in FIG. 8A, the output from the low-pass filter is
, So that the signal amplitude by this circuit does not change.

The configuration of the -45 ° phase shift circuit 43A is as shown in FIG. In this figure, an input signal Vin passes through a high-pass filter including a resistor R43A and a capacitor C43A. Here, the values of the resistor R43A and the capacitor C43A are determined so as to satisfy Expression 2 with respect to the oscillation frequency f1 of the oscillator 41A.

[0053]

F1 = 1 ÷ (2π · R43A · C43A)

By passing through such a high-pass filter, the signal of frequency f1 is subjected to a phase shift of -45 °. However, at the same time as the phase shift, the amplitude is also 3 dB
It will be reduced as much. Therefore, in the circuit shown in FIG. 8B, the output from the low-pass filter is supplied to the amplifier circuit 430A.
, So that the signal amplitude by this circuit does not change.

As a result, the + 45 ° phase shift circuit 42
Carrier signal S1 obtained from the output of A, and -45 °
The carrier signal S2 obtained from the output of the phase shift circuit 43A is a signal that can be expressed by Equation 3 when the oscillation frequency of the oscillator 41A is f1. (Here, A represents a constant, and t represents time.)

[0056]

S1 = A · sin (2π · f1 · t) S2 = A · cos (2π · f1 · t)

Similarly, the + 45 ° phase shift circuit 42
A B- and -45 ° phase shift circuit 43B is also configured. Accordingly, the carrier signal S3 obtained from the output of the + 45 ° phase shift circuit 42B and the carrier signal S4 obtained from the output of the −45 ° phase shift circuit 43B are expressed by the following equation (4).

[0058]

S3 = A · sin (2π · 2 · f1 · t) S4 = A · cos (2π · 2 · f1 · t)

Similarly, the + 45 ° phase shift circuit 42
Carrier signal S5 obtained from the output of C, and -45 °
The carrier signal S6 obtained from the output of the phase shift circuit 43C is represented by Expression 5.

[0060]

S5 = A · sin (2π · 3 · f1 · t) S6 = A · cos (2π · 3 · f1 · t)

Similarly, the + 45 ° phase shift circuit 42
Carrier signal S7 obtained from the output of D, and -45 °
The carrier signal S8 obtained from the output of the phase shift circuit 43D is represented by Expression 6.

[0062]

S7 = A · sin (2π · 4 · f1 · t) S8 = A · cos (2π · 4 · f1 · t)

As described above, the + 45 ° phase shift circuits 42A, 42B, 42C, 42D, and -45 °
At the outputs of the phase shift circuits 43A, 43B, 43C, 43D, eight types of carrier signals S1 to S8 having different frequencies or phases are obtained. Each of these eight carrier signals has a frequency that is an integral multiple of the fundamental frequency f1. When these eight types of carrier signals are compared with each other at the same frequency, the phase shift is 90 degrees. Therefore, these eight types of carrier signals S1 to S8 are orthogonal to each other.

These eight types of carrier signals S1 to S8
Is input to the eight multiplication circuits 44A to 44H. Each of the eight multiplication circuits 44A to 44H has a carrier signal S
The calculation of the product of 1 to S8 and the eight polarity signals p0, p1,... P7 is performed. These results are obtained from the eight amplifier circuits 45A to 45A.
The carrier signals V1 to V8 are amplified by K1 to K8 times to generate carrier signals V1 to V8. That is, the following equation 7 is obtained.

[0065]

V1 = + K1 · A · sin (2π · f1 · t)
. . . When b0 is logic 1. V1 = −K1 · A · sin (2π · f1 · t). . .
When b0 is logic 0. V2 = + K2 · A · cos (2π · f1 · t). . .
When b1 is logic 1. V2 = −K2 · A · cos (2π · f1 · t). . .
When b1 is logic 0. V3 = + K3 · A · sin (2π · 2 · f1 · t)
. . . When b2 is logic 1. V3 = -K3 · A · sin (2π · 2 · f1 · t)
. . . When b2 is logic 0. V4 = + K4 · A · cos (2π · 2 · f1 · t)
. . . When b3 is logic 1. V4 = -K4 · A · cos (2π · 2 · f1 · t)
. . . When b3 is logic 0. . . . V8 = + K8 · A · cos (2π · 4 · f1 · t)
. . . When b7 is logic 1. V8 = -K8 · A · cos (2π · 4 · f1 · t)
. . . When b7 is logic 0. It has become.

As described above, the 8-bit digital signal b
0, b1,... B7, the eight different carrier signals S1 to S8 are modulated and the carrier signals V1 to V8 are modulated.
8 is obtained. The eight types of carrier signals S1 to S8 used here are orthogonal to each other.

When reproducing an optical disk, not limited to the present embodiment, a phenomenon occurs in which the amplitude of a reproduced signal differs depending on frequency components because the size of a light spot used for reproduction is finite. In an optical system generally used, the amplitude of a reproduced signal decreases as the frequency increases. In order to reduce the influence of such frequency characteristics, in the present embodiment, eight amplifier circuits 45A to 45A are used.
The values of the amplification factors K1 to K8 amplified at 45H are set to be different according to the frequencies of the input carrier signals S1 to S8. That is, each amplification factor is set so as to be expressed by Expression 8.

[0068]

## EQU8 ## K1, K2 <K3, K4 <K5, K6
Each amplification factor is set so as to be <K7, K8.

As described above, since the amplification factor differs depending on the frequency, the influence of the frequency characteristic upon reproducing the finished disc is reduced, and a substantially uniform signal amplitude can be obtained.

The eight carrier signals V1 to V8 obtained as described above are all added by the adder 46, and an added signal Vk is obtained. The added signal Vk obtained in this way is a signal whose amplitude changes to both plus and minus, usually around 0V. However, some optical modulators used in cutting machines do not accept negative voltages. In case of such a case,
In the configuration shown in FIG. 6, the adder 47 adds the fixed voltage Vb from the fixed voltage generator 48 to the addition signal Vk to obtain the modulation signal Vm.

The modulation signal Vm obtained from the modulation circuit 4A in this way is sent to the characteristic correction circuit 5A in FIG. 3, and the information recorded as the position displacement of the groove wall is converted into a PP (push-pull) in the tangential direction. ) Converted so that it can be detected as a signal. In addition, the characteristic correction circuit 5A
In, characteristics such as non-linear characteristics unique to the optical modulator 16A are further corrected. The signal Vp obtained in this way is replaced by the optical modulator 16A as a change in the direction of the laser beam L3A, and is finally recorded on the master disk 17.

The error correction code is also added to the information SB output from the digital tape recorder 21B by the error correction code generation circuit 11B, and after interleaving, the 8-bit digital signals b8 and b are output.
9,... B15 are output. Further, the modulation circuit 4B creates a modulation signal Vn for the 8-bit digital signals b8, b9,... B15. This modulation circuit 4
Since the configuration of B is basically the same as that of the modulation circuit 4A,
The description here is omitted.

The modulation signal Vn thus obtained from the modulation circuit 4B is sent to the characteristic correction circuit 5B, and the information recorded as the position displacement of the groove wall is converted into a tangential PP (push-pull) signal. Converted so that it can be detected. In the characteristic correction circuit 5B,
Further, characteristics such as non-linear characteristics peculiar to the optical modulator 16B are corrected. The signal Vo thus obtained is replaced by the optical modulator 16B as a change in the direction of the laser beam L3B, and is finally recorded on the master disk 17.

The configurations of the characteristic correction circuit 5A and the characteristic correction circuit 5B are basically the same. Therefore, only the configuration of the characteristic correction circuit 5B is shown in FIG. In the figure, an input positive value addition signal Vn is supplied to a clock generation circuit (OSC).
Each time the clock signal ADCK is output from the 55 at a constant period, the clock signal ADCK is converted into a digital value by the A / D converter 51. The output of the A / D converter 51 is input to the integration circuit 52, and the value obtained for each clock signal ADCK is integrated. As described later, the characteristic correction circuit 5B
Is recorded as a positional displacement of the groove wall, and then is output in the tangential direction PP (push-pull).
It is assumed that it is detected as a signal. When the detection is made with the PP signal in this manner, the differentiated waveform of the recorded signal is reproduced. Therefore, by integrating in advance in the characteristic correction circuit 5B, the P in the tangential direction is obtained.
When P detection is performed, a signal having a correct waveform can be expected.

The output signal of the integration circuit 52 is input as an address of a ROM (Read Only Memory) 53. In the ROM 53, characteristics for correcting expected non-linear characteristics such as the characteristics of the optical modulator 16B are recorded corresponding to each input address. In this way, a value according to the previously recorded correction characteristic is read, and D /
The analog voltage is converted into the original analog voltage by the A converter 54 and output as the modulation signal Vo. The clock generation circuit 55 oscillates at a sufficiently high predetermined frequency, and the A / D
A clock signal ADCK for driving the converter 51, the integration circuit 52, and the D / A converter 54 is output.

When an example of such an input-output characteristic of the ROM 53 is shown, for example, a curve as shown in FIG. 10 is plotted. A sequence of numerical values according to the characteristics shown in FIG.

The modulation signal Vo thus created is connected to the optical modulator 16B. The traveling direction of the laser beam L2B is modulated by the optical modulator 16B. The laser beam L3B whose light traveling direction is modulated by the light modulator 16B in this way and the laser beam L3A whose light traveling direction is further modulated by the light modulator 16A are connected to the objective lens 7
After passing through No. 3, the disk master 17 is irradiated. This allows the digital tape recorder 21 as an information source to be used.
The information from A is recorded as the positional displacement of the groove wall 1 on the master disk 17, and the information SB sent from the digital tape recorder 21B is recorded as the positional displacement of the groove wall 2 by exposure.

In the disk master 17 on which exposure and recording have been performed in this manner, the groove portions developed and recorded appear as concave patterns. Further, a mother disk is prepared by electroforming. The stamper 23 is created using this mother disk. The injection molding machine 24 repeats the injection molding based on the stamper 23 thus completed, so that the optical disk substrate 25 copied in large quantities can be obtained.

FIG. 11 shows the state of the optical disk substrate 25 thus completed. When a part of the optical disk substrate 25 is enlarged by a means such as a microscope, for example,
The state of the groove 250 is observed as schematically shown in the lower part of FIG. Here, the recording signal is basically a groove (groove) 250, and the upper wall (groove wall 1 (251)) in the figure changes according to the modulation signal Vp. Also, the lower wall in the figure (groove wall 2 (252))
Changes according to the modulation signal Vo. Further, although not shown in FIG.
3 are embedded as pits.

The optical disk substrate 2 thus obtained
In 5, a magneto-optical film having magneto-optical (MO) characteristics is formed by a reflective film forming device 26 such as a sputtering machine, thereby completing a partial ROM disk 27.

Next, referring to FIG. 12, digital tape recorders 21A and 21A will be described in the manner described above.
An optical disk recording / reproducing apparatus 3 for reproducing digital information from a partial ROM disk 27 on which digital information from B is recorded as positional displacement of a groove wall and further applying an MO film as a reflective film and additionally recording the information will be described.

In FIG. 12, a system controller 39 in the optical disk recording / reproducing apparatus 3 receives an instruction from the computer 28 via the interface circuit 30 and controls the operation of the entire optical disk recording / reproducing apparatus 3.
The instructions given from the computer 28 can be roughly classified into R
There are three types: reading data from the OM area, writing data to the RAM area, and reading data from the RAM area.

In FIG. 12, the partial ROM disk 27 is rotated by a spindle motor 31. Spindle motor 31 and optical pickup 32
Is controlled by the servo circuit 35 to perform a predetermined operation.

The laser beam emitted from the optical pickup 32 is reflected by the diffraction grating inside the optical pickup 32 as shown in FIG.
The spot is divided into three spots (spots 321 to 323) shown in FIG. 3 and irradiates the partial ROM disk 27, returns to the optical pickup 32 again, and is converted into an electric signal by a plurality of detectors inside the optical pickup 32. Outputs from the plurality of detectors are amplified to a sufficient amplitude by an amplifier circuit (not shown) provided inside the optical pickup 32, and then input to the matrix operation circuit 33.
The matrix operation circuit 33 includes an operational amplifier, etc., and outputs a magneto-optical signal (MO),
Signals such as a tangential push-pull signal (TPP), an RF signal, a track error signal (TK), and a focus error signal (FS) are calculated. The track error signal (TK) and the focus error signal (FS) are sent to the servo circuit 35, and control is performed so that tracking and focus servo can be correctly obtained. Also,
The RF signal is sent to the PLL circuit 34, which detects the periodically embedded synchronization signal and outputs the channel clocks CK1 to CK1.
CK4 and a timing pulse BCLK are generated. Although not shown, address information for accessing a predetermined location from the RF signal is also decoded. TP
The P signal is supplied to the decoding circuit 6, where the information recorded as the displacement of the groove wall is decoded.

FIGS. 13 and 14 show the relative relationship between three spots (spots 321 to 323) formed on the partial ROM disk 27 and the detector inside the optical pickup 32. FIG. For the center spot 321, the quadrant detectors (A, B,
C, D) are assigned, and the light beam obtained from the spot 321 is divided into four and detected by the respective detectors. In addition, for the spot 322, the signals E and F are detected by the two-segment detector. Similarly, for the spot 323, the signals G and H are detected by the two-segment detector.

FIG. 13 shows the relative relationship between the three spots and the grooves recorded on the partial ROM disk 27 when reading the ROM area. As shown in FIG. 13A, when the ROM area is read, the center of the spot 322 traces the center of the groove 270 among the three spots irradiated from the optical pickup 32 by the tracking servo. And the center of the spot 321 traces the portion of the groove wall 1 (274). At this time, of course, information recorded as the displacement of the groove wall 1 (274) is read. Further, by switching the tracking polarity, the center of the spot 323 is controlled to trace the center of the groove 270 as shown in FIG. 13B, and the spot 321 is traced on the groove wall 2 (275). In this case, the operation is performed to read out information recorded as the displacement of the groove wall 2 (275).

A method of creating a track error signal for realizing such tracking servo is as follows. The E signal and the F signal obtained from the spot 322 and the G signal and the H signal obtained from the spot 323 are described below. Created using The E signal and F signal obtained from the spot 322 and the G signal and H signal obtained from the spot 323 are all input to the matrix operation circuit 33. In the matrix operation circuit 33, these four signals (E,
F, G, H) is calculated by the following equation (9).

[0088]

TK signal = (EF)-(GH)

The TK signal thus obtained is a signal that becomes zero when the central spot 321 traces the central portion of the groove wall 1 (274) or the groove wall 2 (275). Therefore, by using this signal and applying the tracking servo method often used in a normal compact disk or the like, the center spot 321 is always moved to the central portion of the groove wall 1 (274) or the groove wall 2 (275). It can be controlled to trace. Further, by inverting the polarity of the signal obtained by Expression 9, it is possible to trace the central portion of the groove wall opposite to the above-mentioned two groove walls.

In FIG. 14, three spots and a partial radius R are recorded and reproduced in the RAM area.
The relative relationship with the groove recorded on the OM disk 27 is shown. When recording / reproducing in RAM area,
As shown in FIG. 14A, of the three spots emitted from the optical pickup 32 by the tracking servo, control is performed so that the center of the spot 321 traces the center of the groove 270. At this time, of course, information is recorded in the groove 270 as a mark.
Alternatively, information recorded as a mark in the groove 270 is read. Further, by switching the tracking polarity, as shown in FIG.
One can also be traced on land 272. In this case, of course, a mark is recorded on the land 272 and reproduced.

To realize such a tracking servo, a DPP (Differential Push) is required.
h Pull), a method of creating a track error signal can be applied. In DPP, the matrix operation circuit 3
3 is the following equation 1 for four signals (E, F, G, H).
Performs the operation of Expression 0.

[0092]

TK signal = (EF) + (GH)

The TK signal thus obtained is obtained when the center spot 321 traces the center of the groove 270 and when the center spot 321
Is a signal that becomes zero when tracing the central part of. Therefore, by applying the tracking servo method using this signal, it is possible to control the central spot 321 to always trace the central part of the groove 270 or the central part of the land 272.

Further, the matrix operation circuit 33 performs the operation of the following equation 11 on the four outputs (A, B, C, D) from the quadrant detector that has detected the spot 321.

[0095]

## EQU11 ## RF signal = A + B + C + D TPP signal = ABC + D FS signal = AB + CD

In the equation (11), the FS signal is a focus error signal, which is used for focusing the objective lens provided inside the optical pickup 32. Therefore FS
The signal is supplied to the servo circuit 35 and the optical pickup 32
Control is performed so that the light beam emitted by the internal objective lens always focuses on the partial ROM disk 27. Since the RF signal holds information recorded as pits, it is supplied to the PLL circuit 34. TPP
The signal is a tangential push-pull signal.

The matrix operation circuit 33 also detects a magneto-optical signal and outputs it as an MO signal.

Next, a case where information recorded as a ROM area is read will be described. When an instruction to read data in the ROM area is sent from the computer 28, the system controller 39 issues an instruction to the matrix operation circuit 33, and configures the matrix operation circuit 33 so as to obtain the tracking signal TK given by equation (9). I do. As a result, the center of the groove wall is positioned at the light spot 32.
1 traces. The TPP signal holding the information recorded as the displacement of the groove wall is sent to the decoding circuit 6, and the information generated by the digital tape recorder 21A or the digital tape recorder 21B is decoded.

The PLL circuit 34 converts the synchronization signals periodically embedded in the RF signal into channel clocks CK1 to CK1.
CK4 and a timing pulse BCLK are generated. The channel clock CK1 generated here has the same frequency as the carrier signal S1 or S2 used at the time of recording. Similarly, the channel clock CK2 includes the carrier signal S3 or S4 and the channel clock CK3.
Is carrier signal S5 or S6, channel clock C
K4 has the same frequency as the carrier signal S7 or S8. The timing pulse BCLK is a digital signal b recorded on the partial ROM disk 27.
.., B7. That is, the signal is such that a pulse is generated at the switching portion of the digital signals b0, b1,... B7 recorded in the signal obtained from the partial ROM disk 27.

The decoding circuit 6 receives the TPP signal and the PLL circuit 3
The information recorded on the basis of the channel clocks CK1 to CK4 and the timing pulse BCLK is decoded and supplied to the ECC circuit 302. ECC circuit 302
Is the ECC (Err) added in the encoding at the time of recording.
or Correcting Code)
An error in the signal output from the decoding circuit 6 is corrected. Such an error may occur, for example, in the partial ROM disk 27.
This is caused by the above defects and the like.

The signal obtained from the output of ECC circuit 302 in this manner is equal to the information output from digital tape recorder 21A or digital tape recorder 21B. Therefore, for example, when the present optical disk recording / reproducing apparatus is applied to a use similar to a compact disk player, a music signal is reproduced from the speaker by connecting a D / A converter and a speaker to the output of the ECC circuit 302. . Of course, the information recorded by the digital tape recorder 21A or the digital tape recorder 21B may be different, so that the tracking polarity is switched so that the groove wall at the center of the reading spot is changed to the groove wall 1 or the groove wall 2. By switching, for example, two types of music can be enjoyed.

In the optical disk recording / reproducing device 3 shown in FIG. 12, the output of the ECC circuit 302 obtained in this way is connected to the interface circuit 30 and the computer 2
8 so that data can be read.

The internal configuration of the decoding circuit 6 will be described with reference to FIG. Referring to FIG.
1 is a frequency (f1) equal to the carrier signals S1 and S2
However, since the signal is generated by the PLL circuit 34, it is a digital signal that includes many harmonics in addition to the frequency f1 component. Therefore, the channel clock CK1 is connected to the band pass filter 61A,
A frequency component equal to the carrier signal S1, that is, the frequency f1
Are extracted, and unnecessary harmonic components are removed.

The signal consisting of only the frequency component f1 obtained in this way is connected to the + 45 ° phase shift circuit 62A and the −45 ° phase shift circuit 63A, and the phase is changed by ± 45 °. As a result, +45
The output of the phase shift circuit 62A is sin (2π · f
1 · t), and a signal of cos (2π · f1 · t) is obtained at the output of the −45 ° phase shift circuit 63A.

Similarly, the channel clock CK2
Is a signal having the same frequency (f2) as the carrier signals S3 and S4, but is a signal including many harmonics because it is a signal generated by the PLL circuit 34. Therefore, the channel clock CK2 is connected to the band-pass filter 61B, and only the frequency components before and after the frequency f2 are extracted, and unnecessary harmonic components are removed.

The signal consisting of only the frequency component f2 obtained in this way is connected to the + 45 ° phase shift circuit 62B and the −45 ° phase shift circuit 63B, and each of them is changed in phase by ± 45 °. As a result, +45
The output of the phase shift circuit 62B is sin (2π · 2
F1 · t), and the output of the −45 ° phase shift circuit 63B has cos (2π · 2 · f1 · t).
Is obtained.

Similarly, the channel clock CK3
Is a signal having the same frequency (f3) as the carrier signals S5 and S6, but is a signal including many harmonics because it is a signal generated by the PLL circuit 34. Therefore, the channel clock CK3 is connected to the band pass filter 61C, and only the frequency components before and after the frequency f3 are extracted, and unnecessary harmonic components are removed.

The signal consisting of only the frequency component f3 obtained in this way is connected to the + 45 ° phase shift circuit 62C and the −45 ° phase shift circuit 63C, and the phase is changed by ± 45 °. As a result, +45
° The output of the phase shift circuit 62C is sin (2π · 3
F1 · t), and the output of the −45 ° phase shift circuit 63C has cos (2π · 3 · f1 · t).
Is obtained.

The channel clock CK4 is a signal having the same frequency (f4) as the carrier signals S7 and S8, but is a signal generated by the PLL circuit 34.
This is a signal containing many harmonics. Therefore, the channel clock CK4 is connected to the band-pass filter 61D, and only the frequency components before and after the frequency f4 are extracted, and unnecessary harmonic components are removed.

The signal consisting of only the frequency component f4 obtained in this way is connected to the + 45 ° phase shift circuit 62D and the −45 ° phase shift circuit 63D, and the phase is changed by ± 45 °. As a result, +45
The output of the phase shift circuit 62D is sin (2π · 4
F1 · t), and the output of the −45 ° phase shift circuit 63D has cos (2π · 4 · f1 · t).
Is obtained.

The + 45 ° phase shift circuits 62A to 62A-6
2D and -45 ° phase shift circuits 63A to 63D
Can be realized by the method described with reference to FIG. 8A or FIG. 8B.

In this manner, the + 45 ° phase shift circuit 6
2A to 62D and -45 ° phase shift circuit 63A to
The carrier signal obtained from 63D is connected to analog multiplying circuits 66A to 66H, and the optical pickup 3
The multiplication with the TPP signal obtained from 2 is performed. Eight types of carrier signals S1 to S8 used for recording
Are orthogonal to each other. Therefore, in this way, the optical disk recording / reproducing apparatus creates again a signal equivalent to the carrier signals S1 to S8 and can reproduce the original signal again by multiplying the signals.

Outputs of the eight analog multiplication circuits 66A to 66H are connected to integration circuits 64A to 64H. Since the internal configuration of each of the integrating circuits 64A to 64H is the same, FIG. 16 shows the inside of the integrating circuit 64A. As shown in FIG. 16, the input signal is integrated by an integrating circuit including a resistor R64A and a capacitor C64A. However, prior to starting the integration, the capacitor C64A is cleared.
That is, the timing signal B indicating the break of the recorded signal
The analog switch 641A is momentarily turned on immediately before the integration is started by the CLK, and the capacitor C64A discharges the electric charge that has been integrated so far.
It is made to clear.

In the integrating circuit 64A, the capacitor C6
The integrated value appearing as a voltage of 4 A
The signal is output after being amplified by 2A.

As described above, the integration circuits 64A to 64A
64H integrates the outputs of the eight analog multiplication circuits 66A to 66H, respectively. Also, before new data is read from the disc, BC
Each integrated value is cleared by the LK signal.

Outputs from integrating circuits 64A to 64H (FIG. 1)
5, X1 to X8 are shown. ) Are input to the analog comparators 65A to 65H. The analog comparators 65A to 65H compare the input voltages X1 to X8 with a reference voltage (usually 0 volt), and when the voltage is higher than the reference voltage, set logic 1 and the input voltage is lower than the reference voltage. For example, a logic 0 is output. By comparing with the reference voltage in this way, even if there is some noise, it is possible to decode the digital signals b0, b1,... B7 recorded correctly.

Thus, the analog comparator 65
The signals obtained from A to 65H are input to D flip-flops 67A to 67H, respectively, and are latched at the transition points of BCLK. That is, the integration circuits 64A to 64H
Is completed, the outputs of the analog comparators 65A to 65H are latched and held as the outputs of the D flip-flops 67A to 67H. These output signals are the same as those obtained as digital signals b0, b1,... B7 during recording, except for the influence of defects and the like.

Thus, the information obtained from the decoding circuit 6 in this way is sent to the ECC circuit 302, where errors such as defects on the disk are corrected, and then sent to the computer 28 via the interface circuit 30. It is configured as follows. Thus, the information in the ROM area is reproduced.

In the embodiment described above, the decoding circuit 6
Is realized by hardware as shown in FIG. However, recently, DSP (digital signal
A remarkable progress has been made in elements called processors, etc., and this part can be realized by software.

In the above description of the embodiment, for the purpose of correcting the PP (push-pull) characteristic in the tangential direction, as shown in FIG.
Although the configuration provided inside has been described, the present embodiment is not limited to this. For example, the correction of the PP characteristic in the tangential direction can of course be provided inside the optical disk recording / reproducing apparatus shown in FIG.

In the present embodiment, the digital signal b
.. B15 are all 1-bit information. However, the present embodiment is not limited to this.
It is also possible to perform quadrature modulation of the orthogonal signal using 2-bit information. In this case, it is possible to further improve the recording density.

Next, additional recording of data in the RAM area
The reproduction will be described. When data is additionally recorded in the RAM area, the computer 28 instructs the system controller 39 via the interface circuit 30 to perform recording in the RAM area. The system controller 39 changes the configuration of the servo circuit 35 and calculates the track error signal TK by performing the calculation of Expression (10). As a result, the central light spot 321 is shown in FIGS.
The tracking is performed so as to maintain the center position of the groove 270 or the land 272 as shown in FIG.

When performing additional recording / reproduction in the RAM area,
The recording data is sent from the computer 28 to the ECC circuit 303 via the interface circuit 30. The ECC circuit 303 adds an error correction code to the data to be recorded. The data to which the error correction code is added is subjected to appropriate modulation such as EFM modulation or 1-7 modulation by a magneto-optical signal modulation circuit 37, and the laser beam is turned on / off by a laser driver 38 so that the data is recorded on the partial ROM disk 27. Is recorded as a mark. When the marks recorded in this manner are observed, for example, as schematically shown in FIG. 2B, the land 2 between the meandering groove walls is formed.
Information is recorded in 72 as an MO mark column 273. Thus, information is recorded in the RAM area.

The optical disk recording / reproducing apparatus 3 also stores a partial R on which information is additionally recorded as described above.
The OM disk 27 can also be reproduced. In this case, the computer 28 instructs the system controller 39 via the interface circuit 30 to read the RAM area. The system controller 39 changes the configuration of the servo circuit 35 and calculates the track error signal TK by performing the calculation of Expression (10). As a result, the central light spot 321 is tracked to the center position of the groove 270 or the land 272 as shown in FIGS.

Next, the optical disk recording / reproducing device 3 connects the MO signal detected by the matrix operation circuit 33 among the signals obtained from the optical pickup 32 to the magneto-optical signal decoding circuit 36. In the magneto-optical signal decoding circuit 36,
The clock signal contained in the MO signal is extracted to reproduce the clock signal, and the MO signal is reproduced according to the clock signal.
The information that has been additionally recorded is decoded by converting the value into a value. Further, the partial ROM is provided by the ECC circuit 301.
An error caused by the influence of dust or defects existing on the disk 27 is corrected, transferred to the computer 28 through the interface circuit 30, and the read operation is completed. Thus, the information in the RAM area is reproduced.

The description so far is based on the ROM area or the RAM.
In the reproducing operation of the area or the recording / reproducing operation, the position of the light spot is changed as shown in FIG.
17B, the spot 322 and the spot 323 are formed as four-divided detectors as shown in FIGS. 17A and 17B, so that the control of the tracking position of the light spot can be performed without switching. The area and the RAM area can be reproduced simultaneously.

In this case, FIGS. 17A and 17B show the relative relationship between three spots (spots 321 to 323) formed on the partial ROM disk 27 and the detector inside the optical pickup 32. ing. The center spot 321 is assigned a quadrant detector (A, B, C, D) as in FIGS. 13 and 14, and the light beam obtained from the spot 321 is divided into four parts and detected by the respective detectors. Is done. Regarding the spot 322, the signals E1 and E2 and the signals F1 and F2 are detected by the quadrant detector.
Similarly, for the spot 323, the signals G1, G2 and H1, H2 are detected by the four-divided detector.

In FIG. 17, a ROM area and a RAM
This shows the relative relationship between the three beams and the grooves recorded on the partial ROM disk 27 when reading the area. As shown in FIG. 17A, when reading the ROM area while reproducing the RAM area of the groove 270, the center of the spot 322 among the three spots irradiated from the optical pickup 32 by the tracking servo is located at the groove wall. 2 (275) is traced. At this time, of course, information recorded as the positional displacement of the groove wall 2 is read. At the same time, the center of the spot 323 is located at the groove wall 1 (2
74) is traced. At this time, the information recorded as the positional displacement of the groove wall 1 is read.

Further, by switching the tracking polarity, as shown in FIG.
When reading the ROM area while reproducing the AM area, the spot 322 traces on the groove wall 2 (277), and in this case, the groove wall 2 (2
77) to read out the information recorded as the displacement. At the same time, the center of the spot 323 traces the groove wall 1 (276). At this time, the information recorded as the positional displacement of the groove wall 1 (276) is read.

A method of creating a track error signal for realizing such tracking servo is as follows:
As shown in the equation, an E signal is created from E1 and E2 obtained from the spot 322, and F is obtained from F1 and F2.
Create a signal and obtain G1 from spot 323
And G2 from G1 and G2 and H1 and H2
, And an H signal is created using these E, F, G, and H signals. The E and F signals obtained from the spot 322 and the G and H signals obtained from the spot 323 are all input to the matrix operation circuit 33. The matrix operation circuit 33 performs the operation of the above equation 9 on these four signals (E, F, G, H).

[0131]

E = E1 + E2 F = F1 + F2 G = G1 + G2 H = H1 + H2

In FIG. 17, when the RAM area is read, as shown in FIG. 17A, of the three spots irradiated from the optical pickup 32 by the tracking servo, the center of the central spot 321 is read out. Is controlled to trace the center of the groove 270. At this time, of course, information is recorded in the groove 270 as a mark. Alternatively, information recorded as a mark in the groove 270 is read. By switching the tracking polarity, the spot 321 can be traced on the land 272 as shown in FIG. In this case, of course, Land 2
A mark is recorded at a portion 72 and reproduced.

Here, the detector output by the central spot 321 is supplied to the matrix operation circuit 33 shown in FIG. 12 to obtain A + B + C + D output, and this output is supplied to the magneto-optical signal decoding circuit 36 for decoding, and further ECC. Error correction is performed via the circuit 301 to obtain a RAM area output. At the same time, spots 322, 323 on both sides
Is supplied to the matrix operation circuit 33 to output a TPP1 signal or a TPP
Two signals are generated, and the output is supplied to the decoding circuit 6 for decoding, and further error-corrected via the ECC circuit 302 to obtain a ROM area output. In this case, by providing two systems of the decoding circuit 6 and the ECC circuit 302, the groove wall 2 of FIG.
(275) or the groove wall 2 (27 in FIG. 17B).
7) First ROM area and spot 32 on the other side
17 (A) or the second ROM of the groove wall 1 (276) in FIG. 17B.
The two types of ROM areas can be reproduced at the same time.

[0134]

TPP1 = E1 + F1-E2-F2 TPP2 = G1 + H1-G2-H2

Next, the operation in the case where the recording / reproduction of the RAM area is performed and the reproduction of the ROM area is performed at the same time will be described. For example, in the case of recording by magneto-optical (MO) modulation, since the laser light amount of the recording laser power by the optical pickup 32 does not change, only a magnetic field modulation signal from the magneto-optical signal modulation circuit 37 is used. Can be recorded in the RAM area in the same manner as the reproduction of the RAM area described above. Therefore, the above-described reproduction of the ROM area may be performed at the same time.

However, in the case of phase change recording, the laser light amount of the recording laser power by the optical pickup 32 changes depending on the recording signal. In such a case, the above-described TPP1 signal and TPP2 signal are normalized by the laser light amount. After that, the data is supplied to the decoding circuit 6 and decoded, and further, the error is corrected through the ECC circuit 302 and the ROM is read.
An area output can be obtained. Therefore, at the same time, R
Recording and reproduction of the AM area may be performed.

In the above description, the case where the magneto-optical film (MO) and the phase change film (PC) are employed as the recording film has been described. However, the present embodiment is not limited to this. Of course, it is also possible to employ an additional recording film employed in a CD-R or the like as the film.

[0138]

According to the present invention, in a partial ROM disk, a first signal recorded on the inner peripheral side wall surface is read by a light beam irradiating substantially the center on the inner peripheral side wall surface, and the first signal is read on the outer peripheral side wall surface. A groove for reading a second signal recorded on the outer peripheral side wall surface by a light beam that irradiates substantially the center; and a light beam that irradiates a substantially center on the groove or / and on the land. And / or an optical disc provided with a recording / reproducing film for recording / reproducing on lands. Accordingly, since the ROM data recorded on the optical disc of the present invention is recorded as independent information on both walls of the groove, it is possible to realize a higher recording density than the conventional method. further,
RAM data can be recorded between the groove walls on which the ROM data is recorded. Therefore, the optical disc according to the present invention can realize a recording density much higher than that of the conventional optical disc.

Further, the optical disk manufacturing apparatus of the present invention comprises: a master disk forming means for forming a grooved disk master by condensing and irradiating a laser beam onto an optical recording medium by optical means; A duplication disc creating means for creating a duplication disc; and a recording film forming means for forming a reflective film capable of additionally recording on the duplication disc, wherein the master disc creation means transmits a first recording signal that changes in accordance with the input digital information. First recording signal generating means for creating, second recording signal generating means for creating a second recording signal that changes according to the input digital information,
First light control means for displacing the emission direction of the first light beam in accordance with the first recording signal and displacing the inner peripheral side wall surface of the groove, and generating the second light beam in accordance with the second recording signal. An optical disc manufacturing apparatus comprising: second light control means for displacing the emission direction to displace the outer peripheral side wall surface of the groove.

Therefore, in the optical disk manufactured by the optical disk manufacturing apparatus of the present invention, since the ROM data is recorded on both walls of the groove as independent information, it is possible to realize a higher recording density than the conventional method. Becomes
Further, it is possible to record the data of the RAM between the groove walls on which the data of the ROM is recorded. Therefore, the optical disc according to the present invention can realize a recording density much higher than that of the conventional optical disc.

The method of manufacturing an optical disk according to the present invention comprises the steps of: forming a master disk by forming a groove by forming a groove by irradiating a laser beam onto an optical recording medium by optical means; The method comprises the steps of: creating a duplicate disk for creating a duplicate disk medium; and forming a recording film on the duplicate disk medium to form an additional recordable reflective film. A first recording signal generation step of generating a signal, a second recording signal generation step of generating a second recording signal that changes according to digital information, and a first light beam according to the first recording signal. The first light control step of displacing the emission direction of the groove and displacing the inner peripheral side wall surface of the groove, and the second step according to the second recording signal. By displacing the emitting direction of the beam, and a second light control step of displacing the outer peripheral side wall surface of the groove.

Accordingly, in the optical disk manufactured by the optical disk manufacturing method of the present invention, since the ROM data is recorded as independent information on both walls of the groove, it is possible to realize a higher recording density than the conventional method. Becomes
Further, it is possible to record the data of the RAM between the groove walls on which the data of the ROM is recorded. Therefore, the optical disc according to the present invention can realize a recording density much higher than that of the conventional optical disc.

Further, the optical disk recording / reproducing apparatus of the present invention comprises a tracking means for controlling the center position of a light spot formed on an information recording surface of an optical disk by a light beam, and detects a light beam reflected by the optical disk. A light receiving means is provided, and when reading the ROM area, the light spot is controlled so as to coincide with the meandering center of one wall surface of the groove. In addition, when recording / reproducing in the RAM area, the light beam condensing position is controlled so that the light spot coincides with the center of the groove or land.

Therefore, with the optical disk recording / reproducing apparatus of the present invention, it is possible to stably reproduce the information of the ROM recorded as independent information on both walls of the groove. As a result, it is possible to realize a higher recording density than the conventional method. Further, when recording / reproducing RAM data, it is possible to record / reproduce RAM data by moving the center of a spot between groove walls. Thus, the optical disk recording / reproducing apparatus according to the present invention can realize a partial ROM disk having a recording density much higher than that of the conventional one.

Further, the recording / reproducing method for an optical disk according to the present invention includes a tracking step of controlling the center position of the light spot and a light receiving step of detecting a light beam reflected by the optical disk. When reading the ROM area, the light beam condensing position is controlled so that the light spot coincides with the meandering center of one wall surface of the groove recorded on the optical disk. The information in the ROM recorded as independent information can be reproduced stably. As a result, it is possible to realize a higher recording density than the conventional method. Further, when recording and reproducing data in the RAM, it is possible to record and reproduce data in the RAM by moving the spot to the center of the groove or the center of the land. In this manner, by applying the optical disk recording / reproducing method according to the present invention, it is possible to realize a partial ROM disk having a recording density much higher than that of the conventional one.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of a partial ROM disk manufacturing apparatus according to an embodiment.

FIG. 2 is a diagram schematically showing a state of a signal recording surface of a partial ROM disk according to the present embodiment, and FIG.
FIG. 2 shows ROM signals recorded on both walls of the groove.
(B) shows an MO mark string recorded on the land.

FIG. 3 is a block diagram showing an overall configuration of a master disk exposure apparatus of the present embodiment.

4A and 4B are conceptual diagrams schematically illustrating an incident angle of a laser beam and a relative position of a spot according to the present embodiment. FIG. 4A illustrates a spot formed by a laser beam L3A, and FIG.
(B) is a spot by the laser beam L3B.

FIG. 5 is a conceptual diagram schematically illustrating two spots according to the present embodiment and shapes of grooves formed as a result.

FIG. 6 is a block diagram showing a configuration of a modulation circuit in the master disc exposure apparatus of the present embodiment.

FIG. 7 is a block diagram illustrating a configuration of a level conversion circuit in the modulation circuit according to the present embodiment.

FIG. 8 is a block diagram illustrating a configuration of a phase shift circuit in the modulation circuit according to the present embodiment, and FIG.
FIG. 8B shows a -45 ° phase shift circuit.

FIG. 9 is a block diagram showing a configuration of a characteristic correction circuit of the master disk exposure apparatus of the present embodiment.

FIG. 10 is a diagram illustrating an example of input / output characteristics recorded in a ROM in the characteristic correction circuit according to the present embodiment.

FIG. 11 schematically shows a partial enlargement of the optical disc substrate of the present embodiment.

FIG. 12 is a block diagram showing the overall configuration of an optical disk recording / reproducing apparatus for performing additional recording and reproduction on the optical disk of the present embodiment.

FIG. 13 shows an optical disk recording / reproducing apparatus according to the present embodiment,
FIG. 13A is a diagram showing a relative relationship between a spot and a groove recorded on an optical disk when reproducing the OM area. FIG. 13A shows that the center of the spot 321 is located at the groove wall 1 (2).
FIG. 13B shows the case where the center of the spot 321 traces the portion of the groove wall 2 (275) when tracing the portion 74).

FIG. 14 shows an optical disc recording / reproducing apparatus according to the present embodiment,
FIG. 14A is a diagram showing a relative relationship between a spot and a groove recorded on the optical disk when recording and reproducing the AM area. FIG.
14B shows the case where the center of the spot 321 traces the center of the land 272. FIG.

FIG. 15 is a block diagram showing a configuration of a decoding circuit of the optical disc recording / reproducing apparatus of the present embodiment.

FIG. 16 is a block diagram illustrating a configuration of an integration circuit of a decoding circuit according to the present embodiment.

FIG. 17 shows an optical disk recording / reproducing apparatus according to the present embodiment in which R
FIG. 17A is a diagram showing a relative relationship between a spot and a groove recorded on an optical disk when the OM area and the RAM area are simultaneously reproduced. FIG.
When reading the ROM area while reproducing the area, FIG.
(B) shows RO while reproducing the RAM area of the land 272.
This is a case where the M area is read.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Partial ROM disk manufacturing apparatus, 3 ... Optical disk recording / reproducing apparatus, 4 ... Modulation circuit, 5 ... Characteristic correction circuit, 10 ... Disc original disk exposure apparatus, 15 ... Recording laser, 16A, 16B ... Optical modulator, 17 disk master, 18 spindle motor, 19 spindle servo circuit, 21 digital tape recorder,
22 developing and plating apparatus, 23 stamper,
24 ... injection molding machine, 25 ... disk substrate, 26 ...
Reflection film forming device, 27: partial ROM disk,
28 ... Computer

Continued on the front page F-term (reference) 5D029 JB09 WA02 WA27 WA29 WD22 5D090 AA01 BB02 BB03 BB05 BB10 BB11 CC06 CC14 DD02 FF11 GG03 GG11 GG22 KK13 KK15 LL01 5D118 AA26 BA04 BB01 BB03 CA03 BD03 CC03 BD03 CF05 CG04 CG17 CG24 CG32 DA42 5D121 AA01 AA02 AA09 BB26 EE07

Claims (16)

[Claims] 1. An optical disk, wherein a first signal recorded on the inner peripheral wall surface is read by a light beam irradiating substantially the center on the inner peripheral wall surface, and light irradiating substantially the center on the outer peripheral wall surface is read. A beam for reading a second signal recorded on the outer peripheral side wall surface by a beam; and a light beam irradiating a substantially center on the groove or / and the land on the groove or / and the land. An optical disc having a recording / reproducing film for recording / reproducing. 2. The optical disk according to claim 1, wherein a return light obtained by irradiating the inner peripheral side wall surface or the outer peripheral side wall surface with a light beam is first and second in a direction corresponding to a direction in which the groove extends. When light is received by a light receiving element having a light receiving surface divided into two areas, a difference signal between the first and second light receiving results obtained from the first and second areas is the first recording signal or the first signal. An optical disc characterized by changing in response to a second recording signal. 3. The optical disc according to claim 1, wherein the first and second recording signals are generated by modulating a plurality of sets of orthogonal reference signals according to data to be used by a user. An optical disk characterized in that a signal level changes according to a sum signal of the optical disk. 4. The optical disk according to claim 1, wherein said recording / reproducing film is a magneto-optical film. 5. The optical disk according to claim 1, wherein the recording / reproducing film is a phase change film that enables phase change recording. 6. An optical disk manufacturing apparatus, comprising: a master disk forming means for forming a grooved disk master by focusing and irradiating a laser beam onto an optical recording medium by optical means; And a recording film forming means for forming a film on which information can be additionally recorded on the duplicate disc, wherein the master disc generating means generates a first recording signal that changes in accordance with the digital information. First recording signal generating means for generating, a second recording signal generating means for generating a second recording signal that changes in accordance with the digital information, and an emission direction of a first light beam according to the first recording signal. And a first light control means for displacing the inner peripheral side wall surface of the groove, and an emission direction of a second light beam according to the second recording signal. And a second light control means for displacing the outer peripheral side wall surface of the groove by displacing the groove. 7. The optical disc manufacturing apparatus according to claim 6, wherein the first light control means is configured to:
Displacing a condensing position of the first light beam on the optical disc master in a radial direction of the optical disc master from a first reference position to meander an inner peripheral side wall surface of the groove; The means is provided by a displacement in the emission direction.
Displacing the condensing position of the second light beam on the optical disk master in the radial direction of the optical disk master from a second reference position, meandering the outer peripheral side wall surface of the groove, the first and second An optical disc manufacturing apparatus, wherein a reference position is set at a predetermined distance in a radial direction of the master optical disc. 8. The optical disc manufacturing apparatus according to claim 6, wherein the first or second recording signal generating means includes: a plurality of sets of orthogonal reference signals; a plurality of sets of orthogonal reference signals; Generating a data sequence, modulating the reference signal corresponding to each of the data sequences to output a plurality of sets of modulation signals, and adding the modulation signals to form the first or second recording signal. An optical disk manufacturing apparatus, comprising: a signal addition unit that generates a signal. 9. The optical disc manufacturing apparatus according to claim 8, wherein the plurality of sets of orthogonal reference signals are a plurality of sine waves having different frequencies from each other and a plurality of cosine wave signals having a frequency corresponding to the sine wave signal. An optical disk manufacturing apparatus, comprising: 10. The optical disc manufacturing apparatus according to claim 6, wherein the first or second light control means changes a diffraction angle in accordance with the first or second recording signal, thereby changing the first or second light control means. Alternatively, an optical disk manufacturing apparatus characterized in that the emission direction of the second light beam is displaced. 11. The optical disk manufacturing apparatus according to claim 6, wherein said recording film forming means is a magneto-optical film forming means for forming a magneto-optical film. 12. A method for manufacturing an optical disk, comprising: a master disk forming step of forming a grooved disk master by condensing and irradiating a laser beam onto an optical recording medium by optical means; and copying from the disk master. Creating a disc, and forming a recording film on the duplicate disc to form an additional recordable reflective film, wherein the master disc creating step is a first recording that changes according to the digital information. A first recording signal generation step of generating a signal, a second recording signal generation step of generating a second recording signal that changes in accordance with the digital information, and a first recording signal generation step according to the first recording signal. A first light control step of displacing an emission direction of the light beam and displacing an inner peripheral side wall surface of the groove; A second light control step of displacing the emission direction of the second light beam in accordance with the recording signal of (a) and displacing the outer peripheral side wall surface of the groove. 13. An optical disc recording / reproducing apparatus for recording / reproducing information on an optical disc by irradiating a light beam on the optical disc having a read-only area and a recording / reproducing area, wherein the light beam is applied to an information recording surface of the optical disc. Tracking means for controlling the center position of the light spot to be formed; light receiving means for detecting the light beam reflected by the optical disc; and the tracking means, when reading the read-only area, The light beam condensing position is controlled so that the light spot coincides with the meandering center of one wall surface of the groove recorded on the optical disk. The light beam is adjusted so that the spot coincides with the center of the groove or land recorded on the optical disc. Optical disc recording and reproducing apparatus characterized by controlling the light position. 14. The optical disk recording and reproducing apparatus according to claim 13, wherein the light receiving means is formed by dividing a light receiving surface into first and second regions in a direction in which the groove extends. Calculating means for generating a difference signal between the first and second light reception results obtained from the first and second areas, and processing the difference signal to demodulate data recorded in the read-only area An optical disk recording / reproducing apparatus, comprising: a demodulation unit. 15. The optical disk recording / reproducing apparatus according to claim 14, wherein the demodulation means includes: a quadrature signal generation means for generating a plurality of orthogonal signals orthogonal to each other; and a product sum operation of the orthogonal signal and the difference signal. An optical disc recording / reproducing apparatus, comprising: a plurality of product-sum operation means for performing the operation; and decoding means for decoding digital information based on an output of the product-sum operation means. 16. An optical disc recording / reproducing method for recording / reproducing information on an optical disc having a read-only area and a recording / reproducing area by irradiating a light beam on the optical disc, wherein the light beam is applied to an information recording surface of the optical disc. A tracking step of controlling a center position of a light spot to be formed; and a light receiving step of detecting a light beam reflected by the optical disc, wherein the tracking step is performed when reading out the read-only area. Controlling the focus position of the light beam so that the light spot coincides with the meandering center of one wall surface of the groove recorded on the optical disc, and when performing recording / reproducing in the recording / reproducing area, The light spot coincides with the center of a groove or land recorded on the optical disc. Optical disc recording and reproducing method characterized by controlling the condensing position of the light beam.