JPH02289937A - Optical disk - Google Patents

Abstract

PURPOSE:To obtain the optical disk which has both of a read-only region and a write enable region within the same plane by forming the inner peripheral part as the read- only region and the outer peripheral part as the write enable region where recording and reproducing of information are executed and executing the rotation control of a mark length recording system and a mark position recording system at the same angular speed. CONSTITUTION:The inner peripheral part is formed as the read-only region 22 where the formation of the mark length recording system of a high recording density is easy. The write enable region 24 where the recording and reproducing of the information is executed by the mark position recording system suitable for the write enable region is disposed in the outer peripheral part. Namely, the decrease in the recording density of the mark position recording system is prevented by increasing the recording frequency at the time of recording the information in the writing region to two-fold the recording frequency of the read-only region 22, by which the recording density of the write enable region 24 is equal to the recording density of the read-only region 22. The recording of the recording in the two region is executed at the same rotating angular speed, by which the access speed is increased and the recording density is increased. The optical disk having the read-only region 22 and the write enable region 24 in one sheet of the disk substrate is obtd. in such a manner.

Description

[Detailed Description of the Invention] [1 Already Required] Regarding an optical disc that has a read-only area and an area that can be used, one disc j, t may have a read-only area and a writable area. The purpose of the present invention is to realize an optical disc having a read-only area and a writable area, in which the inner periphery is a read-only area in which information is recorded using a mark length recording method, and the outer periphery is a read-only area in which information is recorded using the mark length recording method. It is a writable area in which information is recorded and reproduced by a mark position recording method with a recording frequency twice that of the recording frequency in the method, and the above mark length recording method and the above mark position; , performed at the same rotational angular velocity.

[Field of Application in Industry 1-] The present invention relates to an optical disc having a read-only area and a writable area.

[Conventional technology]

An optical disk is a recording medium that records and reproduces information by irradiating it with laser light or generating a magnetic field if necessary, and there are three types depending on its usage: read-only type, write-once type, and rewritable type. .

A read-only optical disc is formed by forming a reflective film made of a thin metal film such as aluminum on a transparent substrate such as glass or polycarbonate resin molded into a disc shape.
This is a read-only optical disc in which information is recorded on the substrate in a concave and convex shape. In addition, in a write-once optical disc, a recording film made of a material that sublimes easily, such as tellurium (Te), is formed on the substrate -1-, and information is transferred in the form of holes into the two-write recording film by irradiation with laser light. In addition, rewritable optical discs are optical discs that can be written only once and detect information based on the presence or absence of holes.
There are known methods that utilize phase change, etc. 11. The MO type optical disk has a perpendicularly magnetized magnetic film (perpendicularly magnetized film) formed on the substrate -1-, and the magnetic film is heated by irradiating strong laser light and heated by a magnetic head or an auxiliary magnetic field coil. This method records information based on the direction of magnetization by applying a magnetic field. Then, signal reproduction is performed by irradiating a weak laser beam with the external magnetic field removed and detecting the angle of the polarization plane of the reflected light.

This is due to the so-called Kerr effect, in which the angle of the polarization plane of the reflected light differs depending on the direction of the magnetic field of the magnetic domain, or
This uses the Faraday effect, in which the plane of polarization of light rotates when it passes through a magnetic material. In addition, the phase change type is a type in which a special recording film is formed on a substrate in which two phase changes occur between amorphous and crystal or between crystal and crystal due to temperature change G. Recording signals and reproduction are performed by utilizing the property that the reflectance of light differs depending on whether the crystal is in a crystalline state or a non-crystalline state, or whether it is in a first crystalline state or a second crystalline state.

Among the above three types of optical discs, read-only optical discs have the advantage of being able to be copied in large quantities.
Digital audio discs, video discs, etc.6 are used.

In addition, write-once optical disks have a long lifespan, and there is little risk of accidentally erasing the signal after being worn out several times, so they can be used as storage devices to replace document files, magnetic disks, etc., and to store image data. , J: used for model optical discs).

Furthermore, since the J: interchangeable optical disc can be repeatedly rewritten, it is used in external storage devices for computers and the like.

(Problems to be Solved by the Invention) By the way, all conventional optical discs have a recordable area formed on a substrate or a recording film on a substrate. Alternatively, it is used as a memory with a write capacity of 11J, and the reality is that there is still no commercially available optical disc that has both a dedicated area and a writable area on the same surface.

For example, write-once optical discs have a large storage capacity, easy random access, mass duplication, and low cost, so they can be used to store sort processor dictionaries and custom patterns.
It is considered to be used as a small disk, or as a disk that stores computer programs and operating manuals.

However, since the write-once optical discs mentioned above are only for playback and manufactured in a dedicated factory, users can write their own kanji, It is not possible to enrich the dictionary by registering font 1 patterns as external characters, or by registering additional words and phrases according to the user's business.

In addition, patches are often created for programs to add functionality or modify features in the program. ” Patches are generally applied to short programs.

For this reason, if PJ Grano is supplied using a write-once optical disc, the user cannot change the data on the write-once optical disc, so the program J from Pan'5 Yumiko will be modified. Even if it were possible, the user would be forced to bear the expense of purchasing a new write-once optical disc due to the small program update.

In addition, creating a new write-once optical disc every time a correction is made is a huge burden on Blogura J and Supply 4I, and is not practical.

Therefore, from now on, Yuji will be able to write information at will in addition to the read-only area. ν：． The demand for optical discs that also include;'-+iiJ functions is expected to increase.

In the above optical disc, for example, the term 1 that does not need to be rewritten, such as a mathematical formula, is recorded in a dedicated area, and the calculation results and processing results are recorded in the writable fief area. There are also two ways to use it, such as using it.

By the way, as a recording method for an optical disc in which information is recorded by forming irregularities on a substrate, two types of methods are known: a mark length recording method and a mark position recording method.

FIG. 6 is an explanatory diagram of mark length (mdrk Icrgttt) recording ability. In this recording method, the presence or absence of the edge 4 of the recording bin 1-2 formed by laser beam irradiation corresponds to the signals r1'' and rO, respectively, and the black and white signals, which are synchronization signals for information recording, correspond to Signal 6 is recorded corresponding to knock 5.

In response to the signal "1", the scanning laser beam enters the recording bits 1 and 2 from the disk surface j, or the teeth 4, which exit from the recording pins 1 and 2 to the disk surface, responds to the signal ``1''. Disc surface l or recording binoculars 1 and 2 without 4
The plane inside corresponds to the "O" signal.

Information is reproduced by detecting whether or not the energy 3 or 4 of the recording bins 1 and 2 is present at the irradiation position of the reading laser beam corresponding to the clock 5.

On the other hand, Figure 7 shows the mark position.
on) An explanatory diagram of the record power person, 12 kiku 11 noku 1
5th evening, J position G cor 1. 1 signal is recorded, the recording pino I.12 is recorded by laser beam irradiation.
is formed, and if a signal of "0" is recorded, then recording pitches 1-12 are not formed.

In this manner, in the case of the mark position recording method, information is read by detecting the presence or absence of recording pits 1 and 12 at positions corresponding to the clock signal 15.

Comparing the above two recording methods, the mark length recording method records using holes 3 and 4 of the hole (recording bin 2), so it has the advantage of having twice the recording density compared to the mark position recording method. be.

However, in the case of the mark length recording method, the edges 3 and 4 of the bins 1 and 2 are detected in synchronization with the clock signal 5, so position control for accurately detecting the edges 3 and 4 of the recording bin 2 becomes complicated.

For this reason, the mark length recording method is generally used for conventional read-only optical discs, and the mark position recording method is generally used for writable optical discs.

■ In the case of read-only optical discs, a mark length recording method is adopted because it is possible to form unevenness in advance with high positional accuracy, and optical disc rotation control is performed using CLV (Co
(instant linear velocity) method.

On the other hand, in the case of writable optical discs, it is difficult to accurately control the positioning of the recording binoto, so a mark position recording method is adopted, and the rotation control of the optical disc is performed using CAV (Constant Angu).
lar velocity) method.

In the above CLV method, since the linear velocity of recording and re-storing is constant for all trunks, the number of recording bits per l-rank unit increases as the outer side of the disk increases, resulting in a high storage capacity. realizable. However, it has the disadvantage that the rotation control of the spindle motor that rotates the optical disk is complicated.

On the other hand, the CAV method has the advantage that since the rotation of the spindle moke and the recording/reproducing frequency are constant, control is easy, the control circuit system is simple, and the spindle motor can be made smaller. However, the storage capacity per track is 1 1 1 12 The number of marks that can be recorded in the innermost 1-rank (information landscape)
Therefore, the storage capacity of the entire optical disk is 1 L.
It has the disadvantage of being smaller than the CLV method described above.

An object of the present invention is to realize an optical disc that has a read-only area and a writable area on one disc substrate.

[Means and effects for solving the problem] That is, the present invention provides two areas on one optical disc, a read-only area and a writable area, and provides a read-only area where information is only continuously displayed. can form unevenness with good positional accuracy, and
In addition, information is recorded using a mark length recording method that allows information to be recorded at a high recording density, and information is recorded using a mark position recording method in a writable area where information can be rewritten.

Then, the read-only area is placed on the inner circumference of the optical disk, and the writable area is placed on the outer circumference of the optical disk, and when recording information in the writable area, record 1: the wave number is the recording frequency in the read-only area. It is set to twice that.

In this way, since the CAV system, which allows easy rotation control, is adopted, information can be recorded and reproduced, so when used as a peripheral device for a computer, the access speed can be increased. In addition, in order to solve the problem of the CAV method, in which the recording density of information decreases as it moves toward the outside in the radial direction, we adopted the mark length recording method, which has a higher recording density on the inner periphery. The read-only W4 area is easy to form, and the outer periphery is a writable area where information is recorded and reproduced using a mark position recording method suitable for the writable area, which reduces the recording density, which is a drawback of the mark position recording method. By setting the recording frequency when recording information in the write area to twice the recording frequency of the read-only area, the recording density of the writable area is made equal to that of the read-only area.

In addition, the above continuous writing area and the above writable area are as follows:
The read-only areas may be arranged alternately on concentric circles in the radial direction of the optical disc.
Information is recorded using the mark length recording method, and information is recorded and reproduced in the writable area using the mark position recording method.

Then, for example, the read-only area, the 0: writeable area are arranged alternately in the order of the 1118 output exclusive area and the writable area from the innermost circumference side, and the recording frequency of the writeable fill area is adjusted to the recording frequency of the read-only area. By setting the frequency to twice the frequency and recording information in the above two areas at the same rotational angular velocity, access speed and recording density can be increased for the same reasons as mentioned above. I can do it.

In addition, as shown in -1-, the continuous print-only area and the fillable area are alternately arranged, and the rotational angular velocity when recording information in the writeable area by the mark position recording method is , the rotational angular velocity is slower than the rotational angular velocity when reading information from the read-only area, and based on the rotational angular velocity, the recording frequency when information is recorded in the writing area is set to 1111. The recording capacity per track of the read-only area is set to be equal to the storage capacity per track of the read-only area, and the rotational angular velocity when reading information from the writable area is It is assumed that the rotational angular velocity is the same as the rotational angular velocity in -g when reading out.

By lowering the rotational angular velocity in this way, the deterioration of recording sensitivity caused by the decrease in the amount of laser light irradiated when recording information at high rotational angular velocity can be reduced.
This can be prevented when recording information in the fillable area.

Further, in this case, since the rotational angular velocity of the read-only area and the writable area 7 is constant when reproducing information, high-speed access is possible when reading information.

Furthermore, as described in -1-2, the read-only area and the writable area are arranged in a concentric circle -L in the radial direction, and there is a gap for recording information in the writable area by the mark position recording method. , the rotation control j7H is performed by a multi-step CAV method that is variable according to the radial position (radial area) of 1', and the i'iJ variation control of the 5 1G recording frequency is performed corresponding to the rotational angular velocity.

The variable recording frequency control 11' is performed, for example, so that the recording capacity per rank of information recorded in the infiltration possible area is the same as the storage capacity per track of the corresponding read-only area. Therefore, in this case, for example, the rotational angular velocity number when reading out information from the read-only area glass [+1 information] is the same as the rotational angular velocity number when reading out information from the rlI recordable area.

If you do the above, the read-only area and
It is possible to make the memory capacity per rank of iJ function area the same, and the rotational angular velocity when reading information is
2. Since the two areas can be made at the same speed and constant, high-speed access is possible.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of an optical disc 20 according to a first embodiment of the present invention.

The optical disc 20 is made of a transparent substrate made of plastic or the like made of glass, polycarbonate 1, resin, etc. with a radius of 5 inches, and a photosensitive member such as TbFeCo, TbFe, GdFeCo, etc. is coated on the entire surface of the transparent substrate by sputtering or vapor deposition. It was formed by law, etc. 2. When the photosensitive recording member is illuminated with a laser beam spot of high intensity, recording is carried out thermomagnetically, and when a laser beam spot of low intensity is irradiated. In this case, the film becomes a reflective film that reflects the laser beam. Therefore, by irradiating the member with a strong laser beam and constantly applying a weak magnetic field from the outside, it is possible to rewrite information on the photosensitive recording member H using a light modulation method. In the light modulation method, if information has already been recorded, new information is recorded after erasing the existing information. 19 or a protective film, etc.).

As shown in FIG. It is used as area 24.

More specifically, in the continuous distribution area 22, information is recorded using the mark length recording method, and in the double writable area 24, information is recorded using the mark position recording method.

In this embodiment, as shown in Table 1 below, the area from the innermost radius position 35m+++ to 10mm is assigned to the read-only area 22, and the area from radial position 70mm to 105mm is assigned to the writable area 24. Both the read-only area 22 and the writable area are allocated to the optical disc 2 when recording information.
The number of rotations at 0 is the same as 1800 rρm, and the recording (bit) frequency is 3.3 in the read-only area 22.
MHz, and in writable area 24 it is 6.6 MHz.

Table 1 Also, information is recorded in the writable area 24 at a rotation speed of 18
C A V (Cans) with a constant rotational angular velocity of 0 Orpm
This is performed using the LanL Angular Velocity method.

Next, FIG. 2 shows the recording format of the read-only area 22 and the writable area 24.

In the read-only area 22, information is formed in advance by bits (holes) 30 on the board, and the length of the bits 30 (
The bit length) is 1 μm for the cylinder at radial position 35, and for the cylinder at radial position 75.
In mm, it is 2 μm.

This means that in the read-only area 22, the number of rotations is 18.
This is because information is recorded using the CAV method at 00 rpm, and the focus length becomes longer toward the outer periphery.

On the other hand, when the writable area 24 is supplied to the user, the laser beam 1 is set so that the laser beam 1 always maintains a constant position, and the sector position is set to 5a (separate trunk number). It is a formatted form in which only the ID section where the sector number and sector number are written is formed.
・The length of the magnetic domain (or phase change region) 40 corresponding to 30 is 11 tm at the outermost radial position of 7 0 + nm,
It is 1.5 μm at the outermost radius position of 105 mm.

This is because the rotation speed when recording information is the same as 1800 rpm, and the frequency for recording that information (recording frequency)
However, in the writable area @24 (2 of ``J.6M11z and 3.3Ml1z which is the recording frequency of the read-only area 22)
This is because it has doubled. 1-Said 7, U C,
Information is recorded in the writable area 24 using a mark position recording method, but the recording density of the mark position recording method is 1/2 that of the mark length recording method used in the read-only area 22. By making the recording frequency (6.6 Mllz) of the writable area 24 twice the recording frequency (3.3 MHz) of the read-only area 22, the number of records per one track in the read-only area 22 and the rock-accessible area 24 is increased. The density, that is, the 11-rack recording capacity is made to be the same.

In addition, the optical disc 20 when reading (reproducing) information
The number of rotations is 1800 r, which is the same as that at the time of re-recording for both the read-only area 22 and the writable distribution area 24.
pm, therefore, the above read-only area 2
2. The rework time of the above writable area 24 is 6.6M
t{z.

Next, FIGS. 3(a) and 3(b) are schematic diagrams showing the format of sectors in the read-only area 22 and the writable area 24, respectively.

As shown in FIG. 2A, the sector 100 of the read-only area 22 has an ID section 110 consisting of an address section 111, an R/W identification signal 112, etc., and information for absorbing rotation fluctuations of the optical disk 200. No ginap 120,
and a data section 130 consisting of a synchronous signal 9131, a data area 132, and the like.

- Atres part 1. 1 1 is information for identifying the 71 response of the sector consisting of 1 to rank number and sector number, and the R/W identification signal 112 indicates whether this sector is within the read-only area 22 or This signal is used to identify whether the sector is within the write-only area 24.

Further, synchronization signal No. 131 is a signal for not reading data recorded in the data area 132C in synchronization with the clock. Data is recorded in the data area 132.

-F sector 100 is recorded in the form of an uneven shape on the substrate.

Furthermore, the sector 200 of the writable area 24 is shown in FIG.
), sector 1 of the read-only area 22 mentioned above.
It has the same configuration as 00, and the sector 200 for each address part 2l1 is the identification information of the sector 200 address.
indicates that it is a sector within the writable area 24.
? / ID part 210 consisting of W identification {J Zō No. 2 + 2
, a data section 23 consisting of a gasob 220 similar to the gasob 120 described above, a synchronization signal 231 similar to the synchronization signal 131, and a data area 232 in which data is recorded.
It consists of 0.

Writing to the ten sectors 200 is performed by thermomagnetically forming domains. Further, reproduction is performed by irradiating the magnetic domain with a spont of linearly polarized laser light with low intensity.

Next, FIG. 4(a) is a diagram showing an example of an optical disc l-live circuit for recording and reproducing information using the optical disc 20 having the above configuration.

In the figure, a CPU 301 controls each circuit block in the circuit in response to commands sent from a host system such as a computer via a dry interface, and receives commands sent from a second system. It performs controls such as writing incoming data to the relevant sector of the optical disc 20, reading data instructed by the host system from the relevant sector of the optical disc, and transmitting it to the host system via the drive interface.

The optical head 302 collects laser light from a semiconductor laser such as a laser diode and irradiates it onto a target position on the optical disk 20 to perform recording, and also converts reflected light into an electrical signal to reproduce information. It is 2112 notes and consists of an optical system and a drive system.

The optical system is a mechanism that focuses a laser beam spot on the optical disk 20 and detects a relative positional shift between the laser beam spot and the target position on the optical disk 1/disk 20,
Semiconductor laser, lens (canobling lens, condensing lens, objective lens), film f1 (film lens)
Sfurinta, Knife Koninge Prism), /4
It consists of a wave plate, a photodiode, and a wavelength plate. The drive system performs focusing control that causes the objective lens to follow the deflection of the disk surface, and tracking control that causes the objective lens to follow the track deflection, so that the relative positional relationship between the target position of the disk medium 1 and the laser beam slot 1 is always maintained. It is a drive mechanism for maintaining a constant state, and consists of a magnet 1, a coil, and a supporting part 11 on the top.

The data encoded by mark length modulation recorded on the optical disk 20 is outputted from the optical node 302 and converted into a corresponding electrical signal, and then sent to the switch 303, mark length recording decoder 304, and mark position recording. The data is transferred to the decoder 305.

Further, the optical disk 20 is rotated by a spindle motor (not shown), and a rotation control circuit for controlling the rotation of the spindle motor is also included in the optical disk drive circuit. And this rotation control circuit is C
PtJ30], it is controlled by 1.

The disk drive circuit also includes a forcing servo system that maintains the vicinity of the laser beam 1 on the recording surface of the optical disk 20, a seek servo system that moves the target beam spot, and a beam beam spot. It also includes various servo control system circuits such as a tracking servo system that causes the spot to follow the target track of the optical disc 20.

By the way, the mark position recording encoder 404 is
The write data Y output from U3 0 1 is synchronized with the 6.6 Mt{z clock applied from the cloth block 402 to generate a mark position modulated binary waveform sequence Z,
The generated binary waveform sequence Z is output to a laser diode tricycle driver 406 (hereinafter abbreviated as LI driver).

L I) The F light emitting device 406 controls the emission of laser light from the laser diode in the optical sensor 3Q2 based on the L waveform sequence Z. If a signal corresponding to "I" is input, G12 is controlled so that a strong beam of light is emitted from the laser diode, and ""o"a
When this corresponding signal is input, the laser beam is controlled to remain at a weak intensity level.

In addition, the switch 303 and the switch 307 are
'302 does not read information from the read-only area 22 (hereinafter referred to as ROM area readout mode 1), or a mode in which the optical head 302 gradually reads information from the writable area 24 (hereinafter referred to as RAM area readout mode). This is a suinochi that switches and outputs signals input from two input terminals according to each mode (expressed as one).

In the ROM area read mode I, the switch 303 switches to the light F'302? On the other hand, in the RAM area read mode, the encoded data read out from the continuous read only area 22 and subjected to mark length modulation is transferred to the optical hand 302.
The encoded data read out by the mark position modulation in the write-only area 24 is output to the PLL306. In addition, in the continuous readout mode of the ten ROM areas, the coded data modulated by the read mark length, the R
In the AM area read mode 1.', the read mark position modulated encoded data is output to a mark length recording decoder 304 and a mark position recording decoder 305, respectively.

PL L 3 0 6 is a Phasc I, locked loop that generates a synchronization signal corresponding to the basic cycle of encoded data inputted via the switch 303, a decoder 304 for mark length recording, and a mark position recording decoder 304. The generated synchronization signal is output to the digital camera 305.

The mark length recording decoder 30/I and the mark position recording decoder 305 restore the input encoded data to the yta bino 1 column based on the synchronization signal applied from PLI=306. ! JiJ L, Suinoji 3070
Output this.

When the switch 307 is reading the 7th ROM area, the demodulated data/focus sequence output from the mark length recording decoder 304 is outputted from the mark position recording decoder 305 when in the RAM area reading mode. The output demodulated data bit string is sent to the CPU 301.
Output to.

The CPU 301 transmits the data bit string inputted via the switch 307 to the postcombuque via an interface not particularly shown.

In addition, C P TJ 3 0 ] is 11 ROMaJ
In a certain Bi-y output mode or -L RAM area read mode, l. The laser diode is controlled via the D+' laser 406 so that the pin 1 to be read or the magnetic domain to be read is irradiated with a weakly intense laser beam.

Next, the operation when reading the data from the read-only area 22 or the writable area 24 of the optical disc 20 will be explained with reference to FIGS. 4(a) and 4(b).

Normally, when reading
7 is set to the ROMvJ area continuous output mode.

■ Operation when reading a sector from the read-only area 22 of the optical disc 20 When the CPU 301 receives address information (track number, sector number) of data to be read from the host computer, it reads the optical disc 20 via the rotation control unit. Each sector 100 of the track indicated by the track number specified by the above address information is rotated at a rotation speed of 1800 rpm.
The ID section 110 of the I. ．． Reading is performed by irradiating a low intensity laser beam from a laser diode in the optical head via the D driver 406. This successive output of the ID section 110 is performed via the optical head 302, the mark length recording decoder 304, and the switch 307. Address section 1 when I+) section 110 is read out 1. It is determined whether the sector indicated by the address information No. 1 is a sector in the read-only area 22 or a sector in the writable area (S1), and it is identified as a read-only area (S2). ), reads one sector of the ROM area (S3). That is, when the sector 100 is detected while sequentially displaying the ID portion, the data area 132 of the sector 100 is not read out via the optical head 302, the mark length recording decoder 304, and the switch 307.

■ Operation when reading the relevant sector from the writable area 24 of the optical disk 20 The CPU 301 receives the address information (1, Ranok number υ, sector number) of the disk that should not be sold from the post-nimbi 1-night. Then, the optical disk 20 is rotated at a rotation speed of 1800 rpm via the rotation control unit, and the ID section 210 of each sector 200 of the trunk indicated by the track number specified by the address information 12 is transferred to the CD driver 40.
6 through ``zeta light'' and inner 5 diodes, each time a weak-intensity laser beam is irradiated from the 5-diode auto. This I
Reading from the D section 210 is performed via the optical head 302, the mark length recording decoder 304, and the switch 307.

At this time, the R/W identification signal is used to determine whether the sector indicated by the address information is in the read-only area 22 or in the writable area 24 (S1
), after determining that the sector is within the writable area 24 (S2), after reading the ID section 210, the switch 303 and switch 307 are set to RAM area read mode (S4). When the sector 200 is detected while sequentially reading the TD section, the data area 232 of the sector 200 is not read out (S
5). After reading the sector, switch 303 and switch 307 are returned to ROM area read mode (S6)
.

■ Operation when writing data to a sector of the writable area 24 of the optical disk 20 When the CPU 301 receives the address information (1-rank number, sector number) of the data to be written from the boss 1/combuque, the The optical disk 20 is rotated at a rotation speed of 1800 rl)m, and the ID section 210 of each sector 200 of the track indicated by the track number specified by the address information is 1. ．． l') The data cannot be read by irradiating a weak-intensity laser beam from the internal laser diode through the driver 406. This I
The reading of the D section 210 is performed using the optical head 302 and the mark length 1.
This is carried out via the Sagawa decoder 3 0 4 and the switch 307 . It is determined by the R/W identification signal whether the sector indicated by the address information at the time is a sector in the read-only area 22 or in the writable area 24, and it is determined whether the sector is in the writable area 24. After determining that
Mark position recording encoder 404, L I) dryer 4
06, and the data area 23 of the sector 200 of the area 24 in which the information can be written via the optical card 302.
Write in 2. Writable area 2 by R/W identification signal
If it is determined that the sector is not within sector 4, no writing is performed.

Next, the configuration of an optical disc 400 according to a second embodiment of the present invention is shown in FIG.

As shown in the figure, in the second embodiment, read-only areas 410 and writable areas 420 are alternately arranged from the innermost circumference of the optical disc 400.

Information is recorded in the read-only area 410 using the mark length recording method, and information is recorded in the double-writable area 420 using the mark position recording method.

Next, the recording form (radial position, rotation speed, recording frequency) of the first application example of the optical disc 400 of the second embodiment is shown in Table 2 below.

Table 2 shows the radius position of the optical disc 400 from 30 mm to 35 mm4.
0mm ~45+++m, and 50mm ~55+n+
They are arranged concentrically with an interval of 5 mm in the radial direction and a width of 5 mlI1 in the radial direction. Also, the writable area 420
is a radial position of 35 mm to 40 mm of the optical disc 400,
45mm ~ 50fflII1, and 55mm ~ 60+
++m, and similarly to the read-only area 410, they are arranged with five values of radial spacing and a radial width of 5 mm.

Then, a read-only area 410 and a writable area 42
0, the rotational angular velocity is constant, that is, the number of rotations is 3 6 0
The rotation of the optical disc 400 during information reproduction/recording is controlled by the 0 rpm CAV system.

Furthermore, the recording frequency when recording information is 3.3Mt1z for the read-only area 410 and 6Mt1z for the writable area 420.
．． It is 6MIlz.

That is, also in the first application example of this second embodiment,
The recording frequency of the writable area 420 is set to the read-only area 4.
It is twice the recording frequency of 10, and the above two areas 4
Table 3 below shows the recording format of the second application example of the optical disc 400 of the second embodiment so that the storage capacity per track is the same at 10.420, that is, 2.

As shown in Table 3-1, in this second application example, the arrangement of the read-only area 410 and writable area 420 is the same as in the first application example described above. When writing information into the write iJ function area 420 and erasing information, c/j and rotational speed are set to 2400 rpm, and in the j-th application example, the front and rear wheels, and the In1 turning speed become slow. There are 7 things going on.

This has one drawback: when the rotational angular velocity is high, the intensity per medium area of the laser substrate 1 becomes low, and as a result, the recording discrepancy becomes low.
420 with the same storage density.

In this way, the read-only area 410 and the writable area 4
For example, when writing new information related to information recorded at a radial position of 30 mm in the read-only area to an arbitrary sector of the writable area, in the first embodiment, the optical It is necessary to move the optical head to a radial position of at least 70 mm, which takes time for access. position 3
Since it is only necessary to move up to 5 mm, high-speed access is possible.

In the first application example, the writable area 420
Since the read-only area 410 and the read-only area 410 are arranged alternately, new information related to the information recorded in the read-only area 410 can be written to the old writeable area 420 located as close as possible in the radial direction. Access time can be shortened.

This is to improve. In this way, writable area 4
The number of revolutions when writing or erasing information to 20 is 2.
By lowering the recording frequency to 4.4 MHz, the same storage capacity per track as in the first application example of Section 2 is secured.

In addition, the number of rotations for reading information is read-only area/1
Both 10 and writable 8■ area 420 are 360
0 rpm, and the rotation control for reading information is as follows.
This is exactly the same as the first application example above. In addition, the recording frequency when reading the information is 3.5, the recording frequency of the read-only area 410, since the recording density of the mark length recording method is twice that of the mark position recording method as described above. 3
In contrast, it is set to 6.6M11z, which is twice the reproduction frequency when reading the writable area 420.

Next, the recording format of the third application example of the optical disc/100 of the second embodiment is shown in Tables 4 and 5 below. Information recording is performed under the conditions shown in Tables 4 and 5.

1J Table 4 is a table showing the recording format of the writable area 420, and Shiki Table 5 is a diagram showing the recording format of the read-only area U2 410.

As shown in the radial position C1 of Tables 4 and 5, the arrangement of the read-only area 410 and the writable area 420 is the same as in the first application example and the second application example described above.

The number of rotations when writing and erasing information is at a radial position of 40 mm,
Linear speed at 50 mm and 60 mm is 20
m/s, the rotation speed during writing and erasing is at the radial position, 351 nm to 40 mm4
5+nm-50mm, 55nun ~
4777, 3822.318 respectively in 60mm area
It is set to 5 rpm.

In addition, the recording frequency in the writable area corresponds to the number of revolutions at radial positions of 35 mm, 45 mm,
The length (magnetic domain length) at 55 + nm is lμm
8.8 (8.75) Mllz, respectively, so that
9.0MHz, 9.2 (9.17)MHz. In addition, the number of rotations when reading information from each writable area 420 is 540 Q rpm, which is not a constant number of rotations.
Frequency (reproduction frequency) when reading information from each writable area 420 from 0 mm 5 5 mm to 6 0 mm
are 9.9M+Iz., respectively. 12.7MIIz15
．． It becomes 5Mllz.

Further, as shown in Table 5, the rotation speed of the read-only area 410 is set to 5400 r so that it is the same as the rotation speed of the writable area 420, and the recording frequency is (There are two adjacent outer circumferential parts Q1) 1/2 of the U frequency of the possible damage area 5120)
, respectively 5.0 MIIz (prison diameter position 301n [
n-35mm), 6.4Mllz (radius I☆ position 40+nm ~ 45mm), 7.1NMflz
(゛t' radial position 50m+n~55mm).

In this way, by changing the rotational angular velocity in several steps when writing and erasing information in the writable area 420, fluctuations in recording sensitivity in each write OJ function area 420 can be reduced. I can do it. In the first and second application examples of Doki, since the rotational speed when writing and erasing information is constant in all the writable areas 420, the rotational linear velocity becomes faster toward the outer periphery. , the recording sensitivity decreases at the outer periphery. The third application example eliminates this drawback.

In the above embodiments, the writeable area is formed of a recording film for recording information using an optical modulation method, but the present invention is not limited to this, and any perpendicular magnetic material capable of magnetic modulation can be used. Furthermore, it is also possible to form a phase change optical memory using other materials such as A material.

Further, the rotational speed and recording frequency used in this embodiment are not limited to the above-mentioned values, and can be freely set to appropriate values depending on the application.

[Effect of the invention] Information is recorded in advance and has two areas: a read-only area where information can only be read and a writable area where information can be rewritten, so there is no need to worry about it being rewritten. By recording information in a read-only area,
Since rewriting of information can be reliably prevented and the user can freely use the writable area as a work area, it can be used for a variety of purposes and has great practical effects.

4. A concise explanation of side M. FIG. 1 is a horizontal diagram of an optical disc according to the first embodiment of the present invention. FIG. 2 is a diagram showing the recording format of the read-only area and writable area of the first embodiment. FIGS. 3(a) and 3(b) show a read-only area,
FIG. 4 (2l) is a sector configuration diagram of a writable area. FIG. 4(b) is a diagram illustrating the operation of the disk drive circuit shown in FIG. 4(a), and FIG. 5 is a block diagram of an optical disk according to a second embodiment of the present invention. FIG. 6 is an explanatory diagram of the mark length recording method, and FIG. 7 is an explanatory diagram of the mark position recording method.

20... optical disc, 22...Read-only area, 24...Writable area

Claims (1)

[Scope of Claims] 1) In an optical disc (20) having a read-only area and a writable area, an inner circumference is a read-only area (22) in which information is recorded using a mark length recording method, and an outer circumference is the read-only area (22) in which information is recorded using a mark length recording method, and an outer circumference is an optical disk (20) having a read-only area and a writable area. A writable area where information is recorded and reproduced using a mark position recording method with a recording frequency that is twice the recording frequency in the long recording method (
24), and the rotational control of the mark length recording method and the mark position recording method is performed at the same rotational angular velocity. 2) An optical disc having a read-only area and a writable area, wherein the read-only area and the writable area are provided alternately on concentric circles in the radial direction from the innermost circumference. 3) The optical disc according to claim 2, wherein information is reproduced in the read-only area by a mark length recording method, and information is recorded and reproduced in the writable area by a mark position recording method. 4) The optical disc according to claim 3, wherein the recording frequency of the mark position recording method is twice the recording frequency of the mark length recording method. 5) The optical disc according to claim 4, wherein rotation control in the mark length recording method and the mark position recording method is performed at the same rotational angular velocity. 6) The rotational angular velocity when writing information in the writable area by the mark position recording method is slower than the rotational angular velocity when reading information from the read-only area, and based on the rotational angular velocity, A recording frequency for recording information in the writable area is set so that a recording capacity per track of the writable area is equal to a storage capacity per track of the read-only area, and the writable area An optical disc characterized in that a rotational angular velocity when reading information from the read-only area is the same as a rotational angular velocity when reading information from the read-only area. 7) When recording information in the writable area using the mark position recording method, the rotation control is performed using a multi-stage CAV method that varies according to the radial position (radial area), and recording is performed in accordance with the rotational angular velocity. 4. The optical disc according to claim 3, wherein the frequency is variably controlled. 8) The variable control of the recording frequency when recording information in the writable area is such that the storage capacity per track of the information recorded in the writable area is equal to the storage capacity per track of the corresponding read-only area. 8. The optical disc according to claim 7, wherein the optical disc is made to be identical. 9) The optical disc according to claim 8, wherein the rotational angular velocity when reading information from the read-only area and the rotational angular velocity when reading information from the writable area are the same.