JP2000048372A - Optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk by which a desired track is retrieved with a simple configuration and information is stored with high density. SOLUTION: This optical disk 101 has a first rewritable recording area, and a second recording area exclusive for reproducing. The first recording area has spiral shaped groove tracks where projecting and recessed tracks are alternatively arranged. These groove tracks have data recording areas. The second recording area has a projecting and recessed pit configuration and has spiral pit tracks where the reproducing data is exclusively recorded. The first recording area has plural zones. The number of sectors in a zone becomes smaller as the zones move toward the inner side. The leading sectors in each track of the second recording area are arranged in a radial manner and the leading sector of each track in the second recording area and the leading sectors in the first recording area are aligned in at least one radial line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk having a recordable / reproducible area and a read-only fixed information recorded area on a single disk.

[0002]

2. Description of the Related Art In recent years, optical disks on which information can be recorded are:
Because it can hold large amounts of data, audio information data,
It is occupying an important position as a storage device for video information data and various types of information equipment data.However, there is a need for larger capacities, and in order to meet this demand, the information recording density on optical discs must be further improved. Must. The information density of an optical disk is determined by the pitch of information tracks and the information density in the track direction, that is, the linear density of information. To improve the information density on an optical disk, it is necessary to narrow the track pitch and increase the linear density.

[0003] As a conventional optical disk, a micro-grooved groove track having a width of 0.8 µm and a pitch of 1.6 µm is formed in a spiral shape on the surface of a disk-shaped resin substrate, and Te is formed on the surface of the substrate by a technique such as sputtering. 2. Description of the Related Art There is known a recording / reproducing optical disk in which a thin film of a ternary phase-change recording material containing Sb, Ge as a main component is formed, and a protective layer is provided on the thin film. For this resin substrate, a stamper is manufactured based on a master on which concave and convex groove tracks are cut, and a large amount of the resin substrate is copied by a technique such as injection using the stamper.

[0004] One purpose of providing the uneven groove track is to detect a position shift signal between the light beam irradiated on the optical disk and the groove track so that the light beam can be accurately positioned on the groove track. This is for controlling. Generally, a position shift signal between a light beam and a groove track on an optical disk, that is, a track shift signal is detected by a push-pull method. The push-pull method detects a far-field pattern of reflected light or transmitted light from an optical disk with a two-segment photodetector having two light receiving regions, and calculates a difference between photocurrents detected in both light receiving regions on the optical disk. This is a method for detecting a displacement between a groove track and a light beam.

[0005] The magnitude and dynamic range of the track shift signal are determined by the width and pitch of the groove track. In a recording / reproducing optical disc, if the width of the groove track is reduced in order to reduce the pitch, the amplitude of the track shift signal is reduced,
In addition, the dynamic range is narrowed, and the quality of the track shift signal is degraded, so that the tracking control becomes unstable, and the track jumps easily occur due to disturbance such as vibration and shock. In the push-pull method, a pseudo signal is mixed in principle with respect to light beam movement on a photodetector due to disc tilt (tilt) or lens movement (lens shift). And the effect of this becomes large, and it becomes difficult to perform highly accurate tracking control. Furthermore, when replicating by injection using a stamper provided with an uneven groove track, if the track pitch is narrowed, the flow of resin into the uneven groove track becomes poor, and resin shaping becomes difficult.

In order to solve this problem, a concave groove track and a convex groove track are formed so as to be alternately arranged in the radial direction of an optical disk, and information is recorded on both the concave and convex groove tracks. Thus, for example, a proposal has been made to realize a double track density with a concave track pitch being the same as the conventional track pitch (for example, Japanese Patent Laid-Open No.
No. 50330). In this case as well, a track shift signal is detected by the push-pull method, and tracking control is performed based on this signal so that the light beam on the optical disk is positioned on the uneven groove track.

[0007] As a conventional optical disk, a track on which information is recorded in the form of pits is formed in a spiral shape on the surface of a disk-shaped resin substrate, and a reflective thin film of Al or the like is formed on the surface of the substrate by a technique such as sputtering. A formed read-only optical disk is known. This resin substrate is also copied in large quantities by a technique such as injection. As a method of detecting a positional shift signal between a light beam and a track composed of concave and convex pits provided on this read-only optical disk,
A three-beam method or a phase difference method is known. The three-beam method is a method of irradiating an optical disk with three light beams, a reading light beam and two auxiliary beams, and detecting a displacement signal from a difference between two auxiliary beam light amounts reflected by the optical disk. . The phase difference method irradiates one read beam onto an optical disk, receives the reflected light with a four-divided photodetector, adds signals obtained from two light receiving areas having a relative angle, and adds both signals. A track shift is detected from a phase difference of a signal. The track shift detection method used for these read-only optical disks is based on a method in which a pseudo signal is less mixed with the reflected beam movement on the photodetector due to the disk tilt (tilt) or lens movement, and the track pitch is narrowed. Can also perform highly accurate tracking control.

[0008]

There are various uses of an optical disk. For example, when an optical disk is used as a medium for supplying software such as an operating system or a basic dictionary or software for a game, a read-only optical disk in which data is recorded in the form of uneven pits can be copied in large quantities. The optical disk becomes inexpensive. On the other hand, it is desired that the user can additionally write or write desired data to the read-only data recorded on the software supply side according to the read-only data. Therefore, in order to satisfy this requirement, it is necessary to mix an area where read-only data is recorded on one optical disk and an area where recording and reproduction are possible.

When this is realized by an optical disk for recording / reproducing, before shipping the optical disk, necessary data may be recorded in advance on a grooved groove track and used as an area for only reproducing. But in this case,
Since it is necessary to record one by one, it takes time and the cost of the disk becomes high.

In order to solve this problem, there has been proposed an optical disk in which necessary data is recorded in a partial area of the optical disk in the form of concave and convex pits, and the remaining area can be recorded (for example, Japanese Patent Application Laid-Open No. Sho 63). -20769). In this way, it is not necessary to record one by one, and a large number of copies can be made by a technique such as injection, so that the cost of the disc can be reduced. However, this optical disc has a track in a read-only area (hereinafter referred to as a ROM area) composed of pit tracks recorded in the form of concave and convex pits and a recordable area (hereinafter referred to as a RAM area).
It is called an area. Since the track in (1) is a single continuous spiral, it is not possible to realize a high density RAM area. ROM area and RA
When the track in the M area is formed as one continuous spiral track, as described above, the track pitch in the RAM area can be narrower than the track pitch in the RAM area. And it is not possible to realize a high density ROM area.

SUMMARY OF THE INVENTION In view of the above problems, the present invention enables a highly accurate tracking control or a desired track search with a simple device configuration, and a RAM area and R which can be easily manufactured.
It is an object of the present invention to provide an optical disc having both areas of an OM area and suitable for increasing the density of information and a recording method of the optical disc.

[0012]

In order to solve the above problems, an optical disk according to the present invention is an optical disk having a rewritable first recording area and a read-only second recording area, The first recording area includes two convex groove tracks and two concave groove tracks between the convex groove tracks.
Two spiral groove tracks, both the convex groove track and the concave groove track have an area where data is recorded, and the second recording area is formed in the form of uneven pits. It has a spiral pit track on which read-only data is recorded, the first recording area is divided into a plurality of zones, and each zone has a smaller number of sectors in the zone toward the inner zone. The heads of the sectors in each track of the second recording area are radially arranged, and the heads of the sectors in each track of the second recording area and the first recording area are arranged on at least one straight line in the radial direction. The feature is that the head of each sector is arranged.

[0013]

According to the optical disk of the present invention, the pitch of the pit track can be set to any optimum pitch so as to be narrower than the pitch of the concave or convex groove track. And providing a boundary area composed of a specific concave / convex pit pattern that does not appear in the information pit pattern of the mirror section or the ROM area between the convex groove track and the pit track on which information is recorded in the form of concave / convex pits. Accordingly, the boundary area can be detected quickly and easily.

In the optical disk of the present invention, the pitch of the concave or convex groove track and the pitch of the pit track are substantially the same.
There is no need to change the feed rate of the cutting laser beam of the cutting machine, and cutting can be performed easily. In addition, information can be recorded and reproduced at high density while performing tracking control with high precision in the RAM area.

In the optical disk of the present invention, the pitch of the concave or convex groove track and the pitch of the pit track are substantially the same.
There is no need to change the feed rate of the cutting laser beam of the cutting machine, and cutting can be performed easily. Then, between the concave and convex groove tracks and the pit tracks on which information is recorded in the form of uneven pits,
By providing a boundary area composed of a specific uneven pit pattern that does not appear in the information pit pattern of the mirror section or the ROM area, the boundary area can be detected quickly and easily.

According to the optical disk recording method of the present invention, a boundary area is provided between a concave and a convex groove track and a pit track on which information is recorded in the form of concave and convex pits. Since the pitch can be set to any optimal pitch so as to be narrower than the pitch of the concave or convex groove track, the density can be increased and the cutting of the master disc can be facilitated.

In the optical disk recording method of the present invention, the pitch of the concave or convex groove track and the pitch of the pit track are substantially the same. There is no need to change the size of the master, and the master can be cut easily.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the optical disk of the present invention will be described below with reference to the drawings.

First, an optical disk according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1A is a diagram showing an overview of an optical disc according to a first embodiment of the present invention.
In FIG. 1A, reference numeral 101 denotes an optical disk according to the first embodiment; 102, a RAM area for recording and reproducing data;
3 is a ROM in which reproduction information is preformatted in advance
Area, 104 is a boundary area indicating a boundary between the RAM area 102 and the ROM area 103, 105 is a sector, 106a, b,
c is a zone. The optical disc 101 is divided into a plurality of sectors 105 per circumference, and is divided into a plurality of zones 106a, b, c in the radial direction, and the number of sectors per circumference in each zone is constant. Zone 10
6a and 6b are configured as a RAM area 102,
06c is configured as the ROM area 103. FIG.
FIG. 2B is an enlarged plan view near the boundary region 104 shown in FIG. In FIG. 1B, reference numeral 110 denotes a convex groove track in the RAM area 102, 111 denotes a concave groove track in the RAM area 102, and 112 denotes a track in the ROM area 103. The RAM area 102 is provided with two spiral groove tracks, a convex groove track 110 and a concave groove track 111, and information is stored in the convex groove track 110 and the concave groove track 111.
Are recorded on both sides. And RO
The track 112 in the M region 103 is also provided in a spiral shape.

The information in each of the zones 106a, 106b and 106c is formatted so as to be recordable / reproducible by the CAV method. Alternatively, a format corresponding to the MCLV system is performed. Therefore, as shown in FIG. 1B, the length of the sector 105 on the inner circumference side of the zone 106b that is the RAM area 102 matches the length of the sector 105 on the outer circumference side of the zone 106c that is the ROM area 103. Absent.

Here, the optical disk 101 of the first embodiment
FIG. 2 shows the configuration of an embodiment of a cutting machine for cutting corn. In FIG. 2, a laser beam emitted from a laser oscillator 203 is shifted by one track in the radial direction of a substrate 205 in accordance with an output from a formatter 201 which generates preformat data and converts input data to be recorded into a desired format. Through the deflector 204 that deflects the light into a minute range about the pitch, the modulator 2
02 modulates a laser beam, and the modulated laser beam is condensed via an objective lens 204 onto a disk-shaped substrate 205 coated with a photoresist. Further, the rotation control circuit 207 controls the spindle motor 20 for rotating the substrate 205.
8 and the feed control circuit 209 controls the modulator 202
And the recording head 210 including the objective lens 206 is controlled to scan at an arbitrary speed in the radial direction of the substrate 205. The controller 211 controls the formatter 201 and the deflector 2 according to the format of the disc to be cut.
04, the rotation control circuit 207 and the feed control circuit 209 are controlled to cut a desired disc master. Although not shown in the figure, the optical disc 10 is copied in large quantities by a technique such as injection based on the cut master.

In the cutting of the optical disk 101, the basic operation is as follows. The spindle motor 208 is rotated at a constant angular velocity and the recording head 21 is moved from the inner circumference to the outer circumference.
By moving 0, the input data to be recorded and the preformat data which are the outputs of the formatter 201 are sequentially recorded. Here, the optical disc 101 is divided into three zones 106a, 106b and 106c, and the transfer rate of the output data from the formatter 201 is the same in each zone. By increasing the transfer rate of output data from the formatter 201 to the outer peripheral zone 106a, the average recording density of each zone is made equal.

Subsequently, the RAM area 1 of the optical disc 101
02 will be described in further detail. RAM area 102
The sector 105 includes an identification information area 113a having information such as a track address of the information area, a sector address, an error code for each address, and a wobble pit 116 necessary for performing tracking correction.
It comprises a servo area 114a having a and b, and an information area 115a for recording and reproducing information. The pits for identification information provided in the identification information area 113a are arranged substantially on the boundary between the convex groove track 110 and the concave groove track 111, and the adjacent convex groove track 1
10 and the information area of the concave groove track 111 are formed so as to be identified based on the same identification information. When the tracking control is performed on the convex groove track 110 and the concave groove track 111 by detecting the track shift signal by the push-pull method, the polarity of the track shift signal becomes opposite. Therefore,
Even if the identification information pits in the information area of the convex groove track 110 and the concave groove track 111 are the same, there is no problem because the convex groove track 110 and the concave groove track 111 can be determined from the polarity of the tracking control. There is no.

The dashed line 117 indicates the center line of each of the convex groove track 110 and the concave groove track 111. The wobble pits 116a and 116b correspond to the track center line 117 for each track. The data is preformatted by being shifted in the radial direction by a half track pitch so as to be symmetrical and not overlap in the radial direction. The wobble pits 116a and 116b are for correcting an offset included in a track shift signal by the push-pull method using the convex groove track 110 and the concave groove track 111.

That is, the data of the identification information area 113a and the wobble pits 116a and b are generated by the formatter 201 of the cutting machine shown in FIG. 2, and the laser light from the laser oscillator 203 is modulated.
A pit is formed as shown in FIG. If the continuous convex groove tracks 110 are cut in a spiral shape, the concave groove tracks 111 are inevitably formed between the convex groove tracks 110. Convex groove track 1
10 and the concave groove track 111 are provided with identification information separately, the convex groove track 110 and the convex groove track 1 are provided.
In addition to the light beam for cutting the identification information for 11, a light beam for cutting the identification information for at least the concave groove track 111 is required. However, if the identification information is shared by the convex groove track 110 and the concave groove track 111 as in this embodiment, the convex groove track 1
It is possible to use only a light beam for cutting 10 and identification information. Also, the width of the convex groove track 110 or the width of the concave groove track 111, the identification information area 113
If the widths of the pits and the wobble pits 116a and 116b are made substantially equal to each other, when cutting the pits and the wobble pits 116a and 116b in the identification information area 113a, the optical disk using the deflector 204 of the cutting machine is used. By moving the groove track 610 in the radial direction by a half track pitch, the same light beam as the light beam for cutting the convex groove track 610, that is, one light beam can be cut.

Next, the ROM area 103 will be described in more detail. The sector 105 in the ROM area 103 is
Similarly to the RAM area 102, an identification information area 113b having information such as a track address and a sector address of the information area from the beginning, an error code for each address, and an information area 1 in which read-only data is preformatted
15b. In the information area 115b, format information of the optical disc, for example, the ROM area 103,
A range of the RAM area 102, control information necessary for controlling the reproducing apparatus such as recording power information and reproducing power information, or reproduction-only data such as various system software, game software, and various programs are pre-stored. These read-only data are formatted, and are recorded by, for example, the EFM modulation method or the (1-7) RLL modulation method. That is, in the ROM area 103, R
Unlike the AM area 102, the read-only data pits are not continuously formed in a concave and convex shape, but the read-only data pits are continuously arranged in a spiral shape.
Is substantially half of the pitch Ta of each convex groove track 110 in the RAM area 102.

In the ROM area 103, similarly to the RAM area 102, the data of the identification information area 113b and the information area 115b are generated by the formatter 201 of the cutting machine shown in FIG. 2, and the laser light from the laser oscillator 203 is modulated. Then, pits having irregularities are formed in a spiral shape.

Further, the boundary area 104 will be described in detail. The optical disc 101 according to the first embodiment of the present invention is for recording and reproducing from the inner circumference to the outer circumference.
The ROM area 103 is set in c. Therefore, the inner ROM area 103 is cut and the innermost zone 10 is cut.
From the outer peripheral zone 106b adjacent to the RAM area 10c
2 is sequentially cut. Where R
Pitch Ta of convex groove track 110 in AM region 102
Is approximately twice as large as the track pitch Tb of the ROM area 103.
Needs to be doubled (Ta) from the RAM area 102 in the radial direction per rotation. However, it is very difficult to instantaneously double the moving amount when shifting from the ROM area 103 to the RAM area 102.
Boundary area 1 from ROM area 103 to RAM area 102
In No. 04, the track pitch on the disk gradually changes to a double pitch during the time required to stabilize the double movement amount.

The parts 112a and 112b shown in FIG.
The light beam from the recording head 210 of the cutting machine is shifted from the track pitch Tb of the ROM area 103 to the track pitches Te, Tf, Tg, Ta (Tb <Te <Tf <
This shows the center of a track when cutting is performed so as to form a pit in a section where Tg <Ta). In this section, that is, the boundary area 104, the pit is not forcibly cut. Consists of a mirror part formed. By setting a period during which the moving amount of the light beam from the recording head 210 changes in the boundary region 104 formed by the mirror unit, the controller 211 can transmit data for cutting the optical disc 101 in accordance with the timing during the track pitch change. By simply masking the output data of the formatter 201 to be converted, the boundary region 104 can be easily generated.

FIG. 3 is an enlarged and exaggerated cross-sectional view of the optical disc 101 cut in the radial direction. On one surface of a substrate 301 made of polycarbonate resin or the like, convex groove tracks 110, concave groove tracks 111, or read-only data pits of the ROM area 103 are formed. Then, a dielectric film 3 such as SiO2 is formed thereon.
02, a recording material film 303, a dielectric film 304, a reflective layer 305 of aluminum or the like are sequentially provided, and the reflective layer 305 and the protective layer 307 are further bonded by an adhesive.
Reference numeral 6 denotes an adhesive layer made of an adhesive.

The reflection layer 305 is provided to improve the recording sensitivity in the RAM area 102, improve heat radiation, and protect the recording material film 303 from thermal shock.
The recording material film 303 is made of, for example, Te (tellurium), Sb
A phase change type recording material mainly composed of (antimony) and Ge (germanium) is formed by a technique such as sputtering. The dielectric films 302 and 304 are the recording material film 30
3 is for protecting against humidity or thermal shock, and can be omitted.

The phase change type recording material becomes crystalline when heated and then gradually cooled, and becomes amorphous when melted and rapidly cooled. Utilizing this property, a phase-change recording medium reversibly changes between a crystalline state and an amorphous state, and overwrites information in the same place as many times as a magnetic recording medium such as a floppy disk or hard disk. it can. When recording information on a phase change type recording medium, the recording medium is rotated at a predetermined speed, and tracking control is performed so that the light beam is positioned on the groove track, and the intensity of the light beam is adjusted according to a signal to be recorded. The modulation is performed between the non-crystallization level and the crystallization level. For example, when recording so that the recording mark is in an amorphous state, an amorphous mark is formed by irradiating a light beam with an amount of light enough to melt the thin film, and the mark is not melted during a period other than the recording mark. It is crystallized by irradiating a light beam with an amount of light. Therefore, during a period other than the recording mark, whether the previous state is amorphous or crystalline, the state becomes a crystalline state, and overwriting can be performed even at a place where information has already been recorded. The information recorded on the phase-change recording medium is reproduced by utilizing the fact that the reflectance or transmittance differs between the amorphous state and the crystalline state. For example, a weak constant light beam is irradiated, light reflected from the recording medium is received by a photodetector, and information is reproduced by a change in the amount of reflected light.

An example of an apparatus for recording or reproducing information by loading the above-described optical disk 101 will be briefly described with reference to FIG. In FIG. 4, reference numeral 401 denotes a motor for rotating and driving the optical disc 101; and 402, an optical head for emitting laser light to the optical disc 101 and detecting reflected light. The optical head 402 includes a converging lens 421 that converges laser light emitted from a light source (omitted) onto the optical disc 101, and a quadrant photodetector 422 that detects reflected light of the laser light emitted onto the optical disc 101. I have. Here, the four-split photodetector 422 is
Are divided into AC and BD so as to correspond to the radial direction of the optical disc 101, and are divided into AB and CD so as to correspond to the track direction of the optical disc 101. Reference numeral 403 denotes a quadrant photodetector 422.
Signals (A + D) and signal (B +
C), signal (A + B + C + D), signal (A + CB-
D) is a computing unit that computes and amplifies each. Signal (A
+ C-B-D) is a track shift signal by the push-pull method, and indicates a position shift between the light beam on the optical disc 101 and the concave groove track 111 or the convex groove track 110. The signal (A + D) and the signal (B + C) are used to obtain a displacement signal between the light beam on the disk 101 and the track 112 in the ROM area 103. The signal (A + B + C + D) is used to reproduce information recorded on the optical disc 101. Optical disk 10
Numeral 1 is attached to the rotating shaft of the motor 401 and is rotated at a predetermined rotation speed. The converging lens 421 is an actuator
The actuator 404 is composed of a tracking coil provided in the movable unit and a permanent magnet attached to the fixed unit. When a current is applied to this coil, the converging lens 421 is moved in the radial direction of the optical disk 101, that is, the concave and convex groove tracks 111, 110 or RO
It moves so as to cross the track 112 in the M area 103. A focusing coil is also attached to the movable part of the actuator 404. When a current flows through this coil, the convergent lens 421 can move in a direction perpendicular to the surface of the optical disk 101 by the electromagnetic force received by the coil. It is configured as follows. The converging lens 421 is focus-controlled so that the light beam irradiated on the optical disk 101 always has a predetermined converging state. Optical head 40
2 and the fixed part of the actuator 404 are linear motors 4
05 is configured to move integrally in the radial direction of the optical disk 101.

The output signal (A + B + C +) of the arithmetic unit 403
D) is input to a wobble tracking error signal generation circuit 406 for detecting a track shift from the wobble pit, and the wobble tracking error signal generation circuit 40
Reference numeral 6 detects the respective peaks of the reproduction signals of the pair of wobble pits 116a and 116b and generates a signal corresponding to the difference between the two peak levels. The tracking error correction circuit 408 calculates the difference between the output signal (A + CBD) of the calculator 403 and the output signal of the wobble tracking error signal generation circuit 406, and the output signal is used to invert the polarity of tracking control. Polarity inversion circuit 409, output signal of polarity inversion circuit 409, and tracking error correction circuit 408
Is output to the switching unit 410 for switching between the output signal of FIG.

Further, the output signal (A +
D) and (B + C) are input to the phase difference tracking error signal generation circuit 407, and the phase tracking error signal generation circuit 407 outputs the signal (A + D) and the signal (B + C).
This is a circuit for generating a signal corresponding to the track shift based on the phase difference between the two. The output of the switch 410 and the output of the phase difference tracking error signal generation circuit 407 are input to the switch 411, and one of the selected signals is output to the switch 411.
Is input to a first control circuit 413 for driving and controlling the actuator 404 via a phase compensator 412 for compensating the phase of the tracking control system, and the first control circuit 413 Optical disk 10 according to
The actuator 404 is controlled so that the light beam converged on 1 is always located on the center line of the track. The output of the switch 411 is output to the phase compensators 412 and 414.
The second control circuit 415 controls the linear motor 405 so that the convergent lens 421 moves around a natural state according to the output.

Here, at the time of tracking in the RAM area 102, a and c of the switch 411 are connected and the ROM area 1
At the time of tracking in 03, switching is performed by the tracking control switching control circuit 416 so that b and c are connected. In the RAM area 102, the polarity switching control circuit 4
Reference numeral 17 sends a selection signal to the switch 410 to control whether the light beam is positioned on the concave groove track 111 or on the convex groove track 110. For example, when the light beam is positioned on the concave groove track 111, the switch 410 outputs the output signal of the tracking error correction circuit 408, and when the light beam is positioned on the convex groove track 110, the switching is performed. Unit 410 is a polarity inversion circuit 40
9 is output. That is, the polarity of the tracking error signal is inverted between the concave groove track 111 and the convex groove track 110. In the ROM area 103, the phase difference tracking error signal generation circuit 40
7, the track 112 in the ROM area is output.
Control is performed so that the light beam is positioned above.

With this configuration, if the tracking error detection signal is switched for each area of the optical disk having the RAM area 102 and the ROM area 103, the light beam can be accurately positioned at the center of the track. Can be followed.

Here, as described above, the optical disk 101 of the first embodiment has a RAM area 102 and a ROM area 10
The area is divided into three, and a boundary area 104 composed of a mirror section is set at the boundary between the RAM area 102 and the ROM area 103. Since there is no place on the optical disc 101 where no pits are formed over such several tracks, the boundary area 104 can be detected quickly and easily.

As shown in FIG. 1B, the ROM area 10
No. 3 is equivalent to a discontinuous groove track because pits of various lengths are arranged spirally at substantially the same interval as the convex groove track 110 in the direction of the track 112.
The amplitude of the tracking error signal in the ROM area by the push-pull method is smaller than that in the AM area 102, and the tracking accuracy is reduced. Therefore, in the boundary area 104, RA
If the tracking error signal is switched by detecting whether the data has entered the M area 102 or the ROM area 103, the tracking control in the ROM area 103 can be performed with higher accuracy. For example, the RAM area 102
When searching for the track 112 in the ROM area 103 from the above, it is only necessary to detect that the track has crossed the boundary area 104 and switch to the phase difference tracking shown in FIG. Also,
Detecting the entry into the ROM area 103 at the boundary area 104 to prevent the recording power from being emitted, the ROM area 1
It is also possible to prevent the recording material in 03 from being transformed. Thus, by providing the boundary area 104, the boundary between the RAM area 102 and the ROM area 103 can be easily detected, so that the tracking control and the recording and reproduction processing in both areas can be performed with great accuracy. The effect is obtained.

Further, the ROM area 103 and the RAM area 1
It is necessary to change the cutting track pitch twice from the boundary of the area 02, but the RAM area 102 and the RO
The optical disk provided with the M area 103 can be cut continuously with one light beam, and the configuration of the cutting machine is simplified. And the boundary area 10
Regarding the cutting of No. 4, it is possible to easily generate the boundary region 104 composed of the mirror section simply by masking the preformat data from the formatter 201 to the modulator 202. Further, in addition to cutting while continuously changing the pitch in the boundary area 104 composed of the mirror portion as in the present embodiment, once the cutting of the ROM area is performed, the track pitch of the RAM area is set again, and the RAM area is again set. Since the cutting can be performed discontinuously, the cutting of the master is also facilitated. It is sufficient that the boundary area 104 is at least equal to one rotation of the optical disc 101, and may be an area corresponding to an arbitrary plurality of rotations so that the feeding speed is stable.

Here, the track 11 in the ROM area 103
2 has been described, the pitch of the track 112 is substantially equal to the pitch of the concave groove track 111 or the pitch of the convex groove track 110. However, the pitch of the track 112 is not limited to this half pitch. Alternatively, the ROM area 1 can be set to an optimum arbitrary pitch smaller than the track pitch of the convex groove tracks 111 and 110.
03, the density of both the RAM area 102 can be increased.

FIG. 5 is an enlarged plan view of an optical disk according to a second embodiment of the present invention. FIG. 5 is different from the optical disc 101 shown in FIG. 1 only in the boundary area, and the same elements as those in FIG. 1 are denoted by the same reference numerals and detailed description thereof will be omitted. Also,
As with the optical disc 101 in the first embodiment, FIG.
The cutting can be performed using the cutting machine shown in FIG.

In FIG. 5, the read-only data in the information area 115b of the ROM area 103 is, for example, (1-7) R
When recorded by the LL modulation method, the shortest pit length is 2
Then, the maximum pit length and the maximum pit interval are eight. As shown in FIG. 5, in the boundary area 504, a periodic pattern is recorded such that the maximum pit length is 9 or more and the maximum pit interval is 9 or more when the shortest pit length is 2, and this periodic pattern is reproduced by the reproducing apparatus. It is easy to detect. The light beam from the recording head 202 of the cutting machine is changed from the track pitch Tb of the ROM area 103 to the track pitches Te, Tf, Tg, and Ta.
This periodic pattern is recorded in a section where (Tb <Te <Tf <Tg <Ta) changes. Therefore, since this pattern is a data pit pattern that does not conform to the modulation rule of the information area 115b, it becomes easy to detect the boundary area 504.

The optical disk 501 of the second embodiment has the structure shown in FIG. 3, similarly to the optical disk 101 of the first embodiment, and relates to a device for loading or writing information on the optical disk 101 described above. In the RAM area 102, high-precision tracking control for high-density recording is performed as described for the optical disc 101 of the first embodiment. Can be. That is, as shown in FIG.
The M region 103 has a groove track 110 having pits of various lengths in the direction of the track 112 and a groove track 111 having a concave shape.
Are arranged in a spiral at substantially the same interval as the pitch Td, the push-pull tracking can be performed as a pseudo continuous groove, but the tracking control is performed because the quality of the track deviation signal is reduced. Easy to be unstable. Therefore, in the ROM area 103, in order to perform the tracking control with higher accuracy, it is sufficient to switch to the phase difference tracking method as shown in FIG. It can be carried out. Also, basically, the RAM area 10
In order to perform recording in the ROM area 103 and reproduction in the ROM area 103, it is necessary to perform switching processing such as power setting of the recording and reproduction optical heads. When the above-described boundary area 104 is detected, switching processing of recording and reproduction is performed. be able to.

As described above, the optical disk according to the second embodiment of the present invention has a ROM area 103 and a RAM area 10.
Although it is necessary to double the track pitch of cutting from the boundary of 2, the RAM area 102 and the ROM area 10
3 can be continuously cut with one light beam, and the configuration of the cutting machine is simplified.

The ROM area 1 in which the moving amount of the light beam from the recording head 210 of the cutting machine changes.
By setting a boundary area 504 between the RAM area 102 and the RAM area 102 in a specific pattern,
The boundary of the M region 103 can be easily detected.
It is possible to easily switch between tracking control and recording and reproduction processing in both areas. Therefore, ROM
The tracking accuracy in the area 103 can be improved, and in the ROM area 103, the recording power is not emitted, and the recording material can be easily prevented from being transformed.

The track 112 in the ROM area 103
Has been described, the pitch of which is approximately half the pitch of the concave groove tracks 111 or the pitch of the convex groove tracks 110. However, the present invention is not limited to this half pitch. By setting the pitches of the tracks 111 and 110 and the track 112 to respective optimum pitches, the ROM area 103 and the RAM area 1 are set.
02 can achieve high density. It is sufficient that the boundary area 104 is at least equal to one rotation of the optical disc 101,
An area for an arbitrary plurality of rotations can be set so that the feed speed is stabilized. Next, an optical disc according to a third embodiment of the present invention will be described with reference to FIG. FIG. 6A is a diagram showing an overview of an optical disc according to a third embodiment of the present invention. In FIG. 6A, reference numeral 601 denotes an optical disk;
2 is a RAM area for recording and reproducing data, 603 is a ROM area in which reproduction information is preformatted in advance,
04 is the RAM area 602 and R
The boundary of the OM area 603, 605 is a sector, 606a,
b and c are zones. The optical disc 601 is divided into a plurality of sectors 605 per circumference, and is divided into a plurality of zones 606a, b, and c in the radial direction, and the number of sectors per circumference in each zone is constant. The zones 606a and 606b are configured as a RAM area 602, and the zone 606c is configured as a ROM area 603.

FIG. 6B is an enlarged plan view of the vicinity of the boundary 604 surrounded by the broken line shown in FIG. FIG.
6B, reference numeral 610 denotes a convex groove track in the RAM area 602, 611 denotes a concave groove track in the RAM area 602, and 612 denotes a track in the ROM area 603. Convex groove track 6 in RAM area 102
10 and the concave groove track 611 are provided in a spiral shape in parallel, and information is recorded on each of the convex groove track 610 and the concave groove track 611. Then, the track 61 in the ROM area 603
Similarly, in No. 2, it is provided continuously and spirally. In addition, each zone 606a, b, c
It is formatted so as to be recordable and reproducible by the AV system, the length of the sector on the innermost track in each zone is almost equal, and the format is compatible with the MCAV or MCLV system. Therefore, as shown in FIG. 6B, the length of the sector 605 on the inner circumference side of the zone 606b as the RAM area 602 matches the length of the sector 605 on the outer circumference of the zone 606c as the ROM area 603. Absent.

Here, the RAM area 602 will be described in more detail. Sector 605 in RAM area 602
Are an identification information area 613a having information such as a track address and a sector address of an information area from the head, an error code for each address, and a servo area 614a having wobble pits 616a and 616b required for correcting tracking. , An information area 615a for recording and reproducing information. The pits for identification information provided in the identification information area 613a are arranged substantially on the boundary between the convex groove track 610 and the concave groove track 611, and the adjacent pits of the convex groove track 610 and the concave groove track 611 are formed. The information area is formed so as to be identified based on the same identification information. When the tracking control is performed on the convex groove track 610 and the concave groove track 611 by detecting the track shift signal by the push-pull method, the polarity of the track shift signal becomes opposite. Therefore, the convex groove track 6
Even if the identification information pits in the information area of the concave groove track 611 are the same as those of the concave groove track 611, there is no problem because the convex groove track 610 and the concave groove track 611 can be determined from the polarity of the tracking control.

A chain line 617 indicates the center line of each of the convex groove track 610 and the concave groove track 611. The wobble pits 616a and 616b correspond to the track center line 617 for each track. The data is preformatted by being shifted in the radial direction by a half track pitch so as to be symmetrical and not overlap in the radial direction. These wobble pits 616a and 616b are for correcting an offset included in a track shift signal by a push-pull method using a convex groove track 610 and a concave groove track 611. The pitch Td between the convex groove tracks 610 and the concave groove tracks 611 is almost half of the pitch Ta of each convex groove track 610.

Next, the ROM area 603 will be described in more detail. The sector 605 in the ROM area 603 is
Similarly to the RAM area 602, an identification information area 613b having information such as a track address, a sector address, and an error code for each address of the information area from the head, and a wobble pit 6 necessary for correcting tracking.
It comprises a servo area 614b having 16c and 16d and an information area 615b in which read-only data is preformatted. The information area 615b includes format information of the optical disc, for example, a range of the ROM area 603 and the RAM area 602, or control information necessary for controlling the recording / reproducing device such as recording power information and reproduction power information, or various system software and games. Read-only data such as software and various programs are pre-formatted in advance, and these read-only data are recorded by, for example, the EFM modulation method or the (1-7) RLL modulation method. That is, in the ROM area 603, the RAM area 6
02, the read-only data pits are continuously arranged in a spiral shape, but are not continuous grooves having irregularities, and the pitch of the tracks 612 in the ROM area 603 and the convex grooves in the RAM area 602 are different. The pitch of each track 610 is substantially the same pitch Ta.

The optical disk 601 according to the third embodiment is similar to the optical disk 101 according to the first embodiment.
The description is the same as that of the optical disc 101 in the first embodiment, and the description is omitted.
Further, as for the apparatus for recording or reproducing information by loading the optical disk 601 described above, the apparatus shown in FIG. 4 can be used, and as described in the optical disk 101 of the first embodiment, High-accuracy tracking control can be performed for the realization.

Further, for cutting the optical disk 601, the cutting machine shown in FIG. 2 can be used. Optical disc 60 of the third embodiment
In the case of cutting No. 1, similarly to the optical disc 101 of the first embodiment, if the continuous convex groove tracks 610 are cut in a spiral shape, inevitably a concave groove between the convex groove tracks 610 is inevitable. Track 611 is obtained. Convex groove track 610 and concave groove track 611
If the identification information is provided separately, the convex groove track 610 is provided.
At least the concave groove track 61 in addition to the light beam for cutting the identification information for the use and the convex groove track 611.
A light beam for cutting the identification information for one is required. However, if the identification information is shared between the convex groove track 610 and the concave groove track 611 as in this embodiment, only the light beam that cuts the convex groove track 610 and the identification information can be used. If the width of the convex groove track 610 or the width of the concave groove track 611, the width of the pit in the identification information area 613a, and the width of the wobble pits 616a and 616b are substantially equal, the pit in the identification information area 613a Wobble pit 616a, b
When cutting is performed, the light beam that is the same as the light beam that cuts the convex groove track 610, that is, one light beam, is slightly moved in the radial direction of the optical disc 601 using the deflector 204 of the cutting machine. You can cut with a beam. Further, R
The track 612 of the read-only data pit row in the OM area 603 is a convex groove track 610 in the RAM area 602.
Is the same as the track pitch of RA,
From M area 602 to ROM area 603 or ROM
Cutting from area 603 to RAM area 602
Cutting can be performed continuously with one light beam while keeping the amount of movement in the radial direction per circumference of the light beam from the recording head 210 of the cutting machine fixed. As described above, the optical disc 601 according to the third embodiment of the present invention can continuously and accurately cut a disc provided with both a recording / reproducing area and a reproduction-only area with one light beam. The configuration of the cutting machine becomes very simple.

As shown in FIG. 6B, the ROM area 60
In No. 3, since pits of various lengths are spirally arranged in the direction of the track 612, it is equivalent to a discontinuous groove track, and the accuracy is lower than the tracking in the RAM area 602. However, since the track pitch of the ROM area 603 is substantially the same as the pitch of the convex groove tracks 610 of the RAM area 602, the track pitch of the ROM area 603 is the same as that of the concave and convex groove tracks 611 and 610 of the RAM area 602. Push-pull tracking can be performed as a pseudo continuous groove that is sufficiently wider than the pitch. Further, the servo area 614 is also stored in the ROM area 603.
Since b is provided, it is possible to reduce the offset included in the track shift signal due to push-pull tracking. Therefore, since the tracks in the RAM area 602 and the ROM area 603 are continuous, tracking in both areas can be performed continuously by push-pull tracking control.

As described above, in the optical disk according to the third embodiment of the present invention, the track 612 of the read-only data pit row in the ROM area 603 has the convex groove track 610 or the concave groove track 610 in the RAM area 602. Since it is possible to form a continuous spiral with either one of the groove tracks 611, the ROM area 603 and the RAM area 602 can be continuously reproduced with this continuous spiral track. However, the ROM area 603
This is suitable for an optical disk having a wide RAM area 602 and a part of a ROM area 603 from the viewpoint of high density.

Here, if it is necessary to more accurately perform tracking control in the ROM area 603, the apparatus shown in FIG. 4 is used to perform push-pull tracking control in the RAM area 602 and phase difference in the ROM area 603. Tracking control may be used. However, in this case, RA
Processing for switching the tracking control method between the M area 602 and the ROM area 603 is required. In order to perform the tracking control switching, the boundary area including the mirror unit described in the first embodiment of the present invention is provided. Is good.

Therefore, the optical disc 601 of the third embodiment is described.
Will be described with reference to FIG. FIG. 7A is a diagram showing an overview of the optical disc of the fourth embodiment. 7A, reference numeral 701 denotes an optical disk of the fourth embodiment, 702 denotes a RAM area, and 703 denotes an RO.
M area 704 is RAM area 702 and ROM area 703
705 indicates a sector, 706a,
b and c are zones. The optical disc 701 is divided into a plurality of sectors 705 per circumference and a plurality of zones 706 in the radial direction, similarly to the optical disc 601 of the third embodiment.
a, b, and c, and the number of sectors per circumference in each zone is constant. Also, zone 706a,
b is configured as a RAM area 702, and a zone 706c
Are configured as a ROM area 703.

FIG. 7B is an enlarged plan view of the vicinity of the boundary region 704 shown in FIG. 7A. In FIG. 7B,
710 is a convex groove track in the RAM area 702;
711 is a concave groove track in the RAM area 702;
Reference numeral 712 denotes a track in the ROM area 703. R
The convex groove track 710 and the concave groove track 711 of the AM area 702 are provided in parallel in a spiral shape, and information is recorded on each of the convex groove track 710 and the concave groove track 711. Have been. The track 712 in the ROM area 703 is also provided continuously and spirally. The information in each of the zones 706a, b, and c is formatted so as to be recordable / reproducible by the CAV method. The length of the sector on the innermost track of each zone is substantially equal.
The format is compatible with the CAV or MCLV system.

Here, the RAM area 702 is given a different number from that of the RAM area 602 in the optical disc 601 of the third embodiment, but the contents are exactly the same, and the description is omitted.

Next, the ROM area 703 will be described in more detail. The sector 705 in the ROM area 703 is
Similarly to the RAM area 702, an identification information area 713b including information such as a track address and a sector address of the information area from the beginning, an error code for each address, and an information area 7 in which read-only data is preformatted.
15b. In the information area 715b, format information of the optical disc, for example, the ROM area 703,
A range of the RAM area 702, control information necessary for controlling the reproducing apparatus such as recording power information and reproducing power information, or reproduction-only data such as various system software, game software, and various programs are pre-stored. These read-only data are formatted, and are recorded by, for example, the EFM modulation method or the (1-7) RLL modulation method. In the ROM area 703, the RAM area 7
02, the read-only data pits are continuously arranged in a spiral shape, but are not continuous grooves having irregularities, and the pitch of the tracks 712 in the ROM area 703 and the convex grooves in the RAM area 702 are different. The pitch of each track 710 is substantially the same pitch Ta.

Next, the boundary area 704 will be described. The optical disc 701 according to the fourth embodiment of the present invention is for recording and reproducing from the inner circumference to the outer circumference, and has a ROM area 703 set in the innermost zone 706c. Therefore, the inner RO
Cutting the M area 703, the innermost zone 706c
Is sequentially cut from the outer peripheral zone 706b adjacent to the RAM area 702.

Here, since the pitch of the convex groove tracks 710 in the RAM area 702 is substantially the same as the track pitch in the ROM area 703, the moving amount in the radial direction per rotation of the recording head 210 remains fixed. The controller 211 controls the masking of the output data of the formatter 201 for converting the data for cutting in accordance with the timing at the time of recording of the boundary area 704, thereby easily generating the boundary area 704. Becomes possible. Reference numerals 712a, b, and c in FIG. 7B denote tracks when some data pits are recorded without using the boundary area 704 as a mirror.

Since there is no portion where no pit is formed on the track in the entire circumference of the optical disk 701 of the fourth embodiment, the boundary area 704 can be easily detected, and the RAM area 702 can be detected. And a high-speed search at the time of searching the ROM area 703.

The optical disk 701 according to the fourth embodiment is similar to the optical disk 101 according to the first embodiment in FIG.
The description is the same as that of the optical disc 101 in the first embodiment, and the description is omitted.
Further, as for the apparatus for recording or reproducing information by loading the optical disk 701 described above, the apparatus shown in FIG. 4 can be used, and the optical disk 101 of the first embodiment can be used.
As described above, high-accuracy tracking control can be performed for higher density. Therefore, the ROM area 70
In FIG. 3 as well, in order to perform tracking control with higher accuracy, it is sufficient to switch to the phase difference tracking method as shown in FIG. 4, and the above-described boundary area can be switched when 704 is detected. . In addition, since recording and reproduction are basically performed only in the RAM area 702 and only reproduction is performed in the ROM area 703, the above-described boundary area 704 can be detected to prohibit recording or release recording prohibition.

As described above, the optical disc 701 according to the fourth embodiment of the present invention has the wobble pits 716a and 716b.
It is necessary to slightly move the optical disc 701 in the radial direction using the deflector 204 when cutting
The optical disk having the RAM area 702 and the ROM area 703 can be cut continuously with one light beam, and the configuration of the cutting machine is simplified. Further, as for the cutting of the boundary area 104, the boundary area 704 including the mirror unit can be easily generated simply by masking the preformat data from the formatter 201 to the modulator 202.

FIG. 8 is an enlarged plan view of an optical disk according to a fifth embodiment of the present invention. 8 differs from the optical disc 701 shown in FIG. 7 only in the boundary area, and the same elements as those in FIG. 7 are denoted by the same reference numerals and detailed description thereof will be omitted.

When the read-only data in the information area 715b of the ROM area 703 is recorded by, for example, the (1-7) RLL modulation method, if the shortest mark length is 2, the maximum mark length and the maximum mark interval are 8 in length. In the boundary area 804, a periodic pattern is recorded such that the maximum mark length is 9 or more and the maximum mark interval is 9 or more when the shortest mark length is 2, so that the reproduction apparatus can easily detect this periodic pattern. . That is, since this periodic pattern is a data pit pattern that does not conform to the modulation rule of the information area 715b, the boundary area 804 can be easily detected.

As described above, the optical disk of the fifth embodiment of the present invention needs to be slightly moved in the radial direction of the optical disk by using the deflector 204 when cutting the wobble pits 716a and 716b. , RAM area 7
02, the ROM area 703, and the boundary area 804 can be cut continuously with one light beam, and the configuration of the cutting machine is simplified. Also, by setting the boundary area 804 between the ROM area 703 and the RAM area 702 in a specific pattern, the boundary between the RAM area 702 and the ROM area 703 can be easily detected. Processing can be easily switched.

Although the present invention has been described in detail, the present invention is not limited to the embodiments. For example, the optical disk according to the embodiment of the present invention shown in FIGS. 1, 5, 6, 7 and 8 has three zones, but is not limited to three zones. Alternatively, the present invention is applicable to an optical disk configured with one zone. In addition, there is no problem in recording only the ROM area with a constant linear density regardless of the radial position. FIG.
In the apparatus shown in (1), an example in which the phase difference tracking method is used for the ROM area is used, but other tracking methods such as a three-beam tracking method may be used, and the present invention is not limited to the embodiments of the present invention. Further, it goes without saying that the present invention does not relate to a recording material and can be applied to, for example, a magneto-optical recording material.

[0070]

As described above, the first and second embodiments of the present invention are described.
The optical disc in the embodiment of the present invention is symmetric with respect to the center line of the pits for identification information and the concave or convex groove tracks so as to extend over both the concave groove tracks and the convex groove tracks, and is separated in the track direction. Since two wobble pits are provided, it is necessary to change the cutting track pitch at the boundary between the ROM area and the RAM area.
The cutting of the ROM area including the boundary area can be performed continuously without interruption with one light beam for cutting the identification information pit and the wobble pit, and the cutting process and the configuration of the cutting machine are simplified.

Further, since the track of the read-only data pit row in the ROM area is narrower than the track pitch of the convex or concave groove track in the RAM area, the density of the ROM area can be increased. By providing a boundary area composed of a specific uneven pit pattern that does not appear in the information pit pattern of the mirror section or the ROM area, the boundary area can be detected quickly and easily. As a result, when the boundary area is detected, the ROM area is detected. High-precision tracking control and switching of recording / reproducing processing can be performed which are adapted to the area and the RAM area, respectively.

Further, since the boundary area is provided,
The optimum track pitch for achieving high density can be set for both the RAM area and the ROM area, and the cutting can be performed by changing the track pitch in the boundary area.

Further, in the optical disk according to the third embodiment of the present invention, one light beam is applied to the RAM area and the ROM area while keeping the same cutting track pitch from the boundary between the ROM area and the RAM area. The cutting process and the structure of the cutting machine can be simplified because the discs provided with both can be cut continuously. Since the track pitch of the ROM area is the same as the track pitch of the groove track having a convex or concave shape, the quality of the track shift signal in the ROM area is less deteriorated, and the wobble pits are provided also in the ROM area. Since the tracking control in the ROM area can be performed by the tracking control method in the RAM area without using another tracking control method, the cost and size of the recording / reproducing apparatus can be reduced.

The optical disks according to the fourth and fifth embodiments of the present invention have the effect of simplifying the configuration of the cutting machine in the optical disk according to the third embodiment, while providing the boundary region by providing a boundary region. 1st and 2nd
RAM area and R
Switching processing of the tracking control method in the OM area,
By performing switching processing between recording and reproduction in the RAM area and ROM area when the boundary area is detected, accurate tracking control and recording or reproduction processing in both the RAM area and the ROM area can be easily performed. It has a great effect.

According to the optical disk recording method of the present invention, a boundary area is provided between concave and convex groove tracks and a pit track on which information is recorded in the form of concave and convex pits. Since the pitch can be set to an optimum arbitrary pitch so as to be narrower than the pitch of the concave or convex groove tracks, the density can be increased, and one optical disc having a RAM area and a ROM area can be provided. With this light beam, cutting can be performed continuously, so that the configuration of the cutting machine is simple and the cutting of the master is also easy.

Further, by setting the pitch of the pit track to an optimum pitch smaller than the track pitch of the concave or convex groove track, the ROM area, RA
High density can be achieved for both M regions.

Further, in the optical disk recording method of the present invention, since the pitch of the concave or convex groove track and the pitch of the pit track are substantially the same, when the master is cut, the It is not necessary to change the laser beam feed speed at a constant rate, and it is possible to cut a disc provided with both a recording / reproducing area and a read-only area accurately and continuously with one light beam. The configuration can be simplified.

[Brief description of the drawings]

FIG. 1A is an outline view of an optical disc according to a first embodiment of the present invention, and FIG. 1B is an enlarged plan view of the vicinity of a boundary area of the optical disc in the embodiment.

FIG. 2 is a configuration diagram of a preferred cutting machine for cutting an optical disc in the present invention.

FIG. 3 is an enlarged sectional view of an optical disk according to the present invention.

FIG. 4 is a block diagram of an apparatus suitable for recording or reproducing information on an optical disk according to an embodiment of the present invention.

FIG. 5 is an enlarged plan view showing a boundary area of an optical disk in a second embodiment of the present invention;

FIG. 6A is a conceptual diagram of an optical disc in a third embodiment of the present invention, and FIG. 6B is an enlarged plan view of a boundary area of the optical disc in the third embodiment.

FIG. 7A is a conceptual diagram of an optical disk according to a fourth embodiment of the present invention, and FIG.

FIG. 8 is an enlarged plan view showing a boundary region of an optical disc in a fifth embodiment of the present invention;

[Explanation of symbols]

 Reference Signs List 101 optical disk 102 RAM area 103 ROM area 104 boundary area 105 sector 106a, b, c zone 110 convex groove track 111 concave groove track 112 track 113a, b in ROM area 103 recognition information area 114a servo area 115a, b information area 116a, b Wobble pit

Claims (1)

[Claims] 1. An optical disc having a rewritable first recording area and a read-only second recording area,
The first recording area has two spiral groove tracks, that is, a convex groove track and a concave groove track between the convex groove tracks, and the convex groove track and the concave groove track. Both tracks have an area where data is recorded, and the second recording area has a spiral pit track on which read-only data is recorded in the form of uneven pits. The first recording area is divided into a plurality of zones, and each zone has a smaller number of sectors in the zone toward the inner zone, and the head of the sector in each track in the second recording area is radially arranged, and An optical disc in which the head of a sector in each track of the second recording area and the head of each sector of the first recording area are aligned on at least one straight line in a direction.