JPH0562357A - Optical disk and recording method therefor - Google Patents

Abstract

PURPOSE:To increase recording capacity per face without decreasing access speed by equalizing the recording capacity per track in the same recording zones and differentiating it in different zones. CONSTITUTION:The recording zone of an optical disk is divided into plural recording zones having 2n lines of tracks. This (n) is a natural number and is set in such a manner that the recording capacity per track is mutually equal in the same recording zones and different in the different zones. Then, since the line recording density for each recording zone is mutually equalized, the recording capacity is increased. The number of total recording bits in a data area radius R of the optical disk is expressed by the product of total recording bits per sector multiplied and the sectors in one track. Thus, the number of sectors of the track T2 in the outermost radius R2 against the track T1 in the innermost radius R1 is secured. And, by equally dividing the data recording zone, complexity is reduced and the large recording capacity is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc having a large storage capacity and a high data access speed, and a recording method for the optical disc.

[0002]

2. Description of the Related Art Conventionally, a write-once or rewritable optical disk for data storage exhibits superiority in access time and seek time.
(Constant Angular Velocity) method is used.
The storage capacity of the optical disk is determined by the number of recordable marks on the innermost circumference of the disk recording area, which is the storage capacity per track.

In fact, the International Organization for Standards of optical disks for data storage
As standardization documents, there are ISO / IEC DP 10090 for 3.5-inch optical discs and ISO / IEC DIS 10089 for 5.25-inch optical discs. This recording data is recorded on an optical disk for data storage by a recording method combining the optical modulation method and mark length recording shown in FIG.

[0004]

However, although the maximum recording density is achieved in the innermost circumference of the optical disk as described above, the same recording capacity is used for all tracks by using the CAV method. The recording density on the outer peripheral side becomes lower than the recording density on the inner peripheral side. For this reason,
The total storage capacity is CLV (Constant Linear Vein)
It is less than the storage capacity of the (locity) method.

In view of the above-mentioned circumstances, the present invention can easily increase the recording capacity per surface without decreasing the access speed of the optical disk according to the new physical recording format, and the recording of the optical disk and the optical disk. It is intended to provide a method.

[0006]

An optical disk according to the present invention is an optical disk in which a plurality of recording tracks are recorded and formed, and the recording area of the optical disk has a plurality of recording zones having 2 ⁿ (n is a natural number) tracks. In the same recording zone, the recording capacities per track are equal to each other, the recording capacities per track are different in different recording zones, and the linear recording densities of the respective recording zones are substantially equal to each other. As a result, the above-mentioned problems are solved.

Next, in the optical disc recording method according to the present invention, the recording area of the optical disc is divided into a plurality of recording zones having 2 ⁿ (n is a natural number) tracks, and one track is formed in the same recording zone. The above-mentioned problems are solved by recording in such a manner that the recording capacities are equal to each other and the recording capacities per track are different in different recording zones so that the linear recording densities in the respective recording zones are substantially equal to each other. ..

[0008]

According to the optical disc and the optical disc recording method of the present invention, the linear recording densities in the divided tracks of the innermost recording zone and the outermost recording zone are made substantially equal to each other, and high-speed access is easily performed. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical disc and an optical disc recording method according to the present invention will be described with reference to the drawings.

The optical disk and the method for recording the optical disk according to the present invention, in an optical disk in which a plurality of recording tracks are recorded and formed, the recording area of the optical disk is 2 ⁿ (n).
Is a natural number), and the recording capacities per track are equal in the same recording zone, and the recording capacities per track are different in different recording zones. By recording the linear recording densities for each to be approximately equal to each other,
The recording capacity of the optical disc can be increased.

A specific physical format principle for realizing the above-described optical disc and the optical disc recording method will be described with reference to FIG. FIG. 1 shows a physical format of an optical disc. The length of one track on the optical disk is represented by the length L of the circumference. Therefore, the length of one track of this optical disc varies depending on the radius R of the optical disc as shown by L = 2πR (1). The length of this one track is, for example, that the recording tracks arranged in the circumferential direction at the radius R of the optical disk are equally divided into K sectors from the first _zero sector S ₀ to the K−1 th S _K−1 sector. ..

Here, the total recording bit number M _R in the radius R of the optical disk is the total recording bit number m _R per sector.
And the number of sectors in one track, K, are represented by m _R K. Further, the recording density (reciprocal number) d of one track d
Is expressed as d = (2πR) / M _R (2) as a required length per bit.

Therefore, as shown in FIG.
At 0, the recording density in the track T ₂ of the outermost peripheral diameter R ₂ of the recording area with respect to the track T ₁ of the innermost diameter R ₁ of the recording area, if the total number of bits per sector in each track are equal, the ratio It decreases to R ₁ / R ₂ . In order to suppress the loss at the outermost circumference diameter R ₂ , the number of sectors K ₂ within the outermost circumference diameter is K ₂ ≈K ₁ × R ₂ / R ₁ (3) For the number K ₁ , (R
_The recording density can be secured by multiplying by ₂ / R ₁ ).

However, it is obvious that the division of the data recording area increases the complexity of control such as control of switching the rotation speed of the spindle motor. To reduce this complexity, the recording region (R ₂ -R ₁₎ it is convenient to evenly min. That is, the recording area (R
₂ -R ₁₎ the zone number _{N (R 2 -R 1) /} N by evenly dividing.

If the number of recording zones N = 2 and the number of sectors in the recording zone Z ₁ is K ₁ , the recording zone Z 1
Sector number K ₂ in _2, will be provided the boundaries of recording zone in an intermediate position (R ₂ + R ₁₎ / 2 of the innermost radius R ₁ and the outermost radius R _2, the relationship in equation (3), K ₂ ≅K ₁ × (R ₂ + R ₁ ) / (2 × R ₁ ) (4) By setting the number of sectors K ₁ and K ₂ according to the zone areas in this way, the recording densities of the two areas can be made to be substantially the same value, and the recording capacity of the conventional data recording area can be limited to a limited data recording area. It becomes possible to secure a large recording capacity in comparison with the above.

In the divided recording zone number N of the optical disk, the recording zone N is an integer of 2 or more. By the way, when the number of tracks in each recording zone is calculated by dividing the total number of tracks by the number N of recording zones, strictly speaking, a fraction may occur. In this case, the fractional number of tracks may be adjusted in the outermost final recording zone.

The recording capacity of the optical disk according to the present invention is
The recording capacity tends to increase as the number N of recording zones increases. This tendency is shown in the graph of FIG. 2 in which the conventional recording capacity is standardized to 1 and the recording capacity ratio is increased. In FIG. 2, the number of sectors K of the optical disk actually takes only an integer value, but the value of the number of sectors K is set to a constant value by using the size of the optical disk, and the formula (4) is used. To obtain the recording capacity ratio. From the graph of FIG. 2, the number of recording zones is increased in the recording capacity ratio up to N = 2 to 10,
In particular, it can be seen that the recording capacity ratio is efficiently increased in the vicinity of the number of recording zones N = 2 to 5.

A specific example using this principle will be described with reference to the optical disc shown in FIG. The 5.25-inch optical disk 10 of the ISO standard ISO / IEC DIS 10089 described above has a track pitch of 1.6 .mu.m with a section having a radius R = 30 to 60 mm as a recording area. Therefore,
The total number of tracks in the 30 mm recording area is 18751 tracks.

In this embodiment, the optical disc 10 has a recording zone number N = 2 and a radius R = 4 from the center of the optical disc.
It is divided into two with a border of 5 mm. The divided optical disk has K ₁ = 17 sectors per track in the innermost recording zone Z ₀ , and the outermost recording zone Z ₁
In the above, the number of sectors K ₂ per track is 17 × (60 + 30) / (2 × 3) from the relation of the above equation (4).
0) = 25.5 sectors are calculated. In the outermost recording zone Z ₁ , the recording tracks arranged in the circumferential direction are equally divided into the number of sectors K ₂ = 25. The total recording bit number m _R per sector is set to 1 Kbyte = 1024 bytes.

The number of tracks in the recording zone Z ₀ is 9375 tracks from the _0th track number T ₀ to the 9374th track number T ₉₃₇₄ . The reciprocal of the maximum recording density in this recording zone Z ₀ is 1.02 μm.
/ Bit. Similarly, the number of tracks in the recording zone Z ₁ is 9376 from the 9375th track number T ₉₃₇₅ to the 18750th track number T _18750.
Become a truck. The reciprocal of the maximum recording density in this recording zone Z ₁ is 1.04 μm / bit. The number of bits in the sector having the maximum recording density is 1
It is 360 × 8 bits.

If 1 Kbyte can be recorded in one sector by dividing the optical disk into recording zones in this way, the data recording capacity will be the same as the conventional ISO / IEC DIS 1008.
9 403 for data amount of 326 Mbytes in the standard
It can be increased to M bytes. With the method described above, the value of the number of recording zones to be divided can be arbitrarily selected, and the degree of freedom per surface can be increased. Further, the divided recording zones can be set to have substantially the same number of tracks.

However, by dividing the recording area, the optical disk drive apparatus needs complicated control such as changing the rotation speed of the spindle motor for each recording zone.
Therefore, the present invention proposes a method of dividing the data recording area based on the above-described principle to increase the recording capacity of the recording area while reducing the complexity of the control as described above.

The optical disk 10 of the present invention is an optical disk 1.
The 0 recording area is divided into 2 ⁿ (n is a natural number) tracks. With this division, the recording area of the optical disk is divided into two.
The recording capacity is divided into a plurality of recording zones for every ⁿ tracks, the recording capacities per track are equal in the same recording zone, and the recording capacities per track are different in different recording zones. The recording densities can be made substantially equal to each other. Further, the discrimination signal ID of the optical disc 10 is convenient because it uses a digital signal handled in binary units.

As a specific example, when the total number of tracks on the optical disk is, for example, 32768 tracks = 2 ¹⁵ , the number of tracks in one recording zone is 2 ¹³ (= 8).
192) Track address 15
The upper 2 bits of the bits can be used as they are as the zone address. The recording area of each data at the time of 4-division can always be checked by the zone address of the upper 2 bits, and the control becomes easy. However, since the total number of tracks is not normally 2 ⁿ tracks, some fractional tracks occur. This fractional track is dealt with by including it in the last recording zone for adjustment.

The number N of recording zones into which the optical disk 10 is divided can be divided into various values according to the track pitch TP and the data recording area width R _DB , as described above. Here, this relationship will be described. The total number of tracks TN in the data recording area is TN = R _DB / TP (5) As described above, the width R _B of each recording zone is 2 ⁿ
When divided into tracks, the recording zone number N (N = 0, 1, 2, ..., N-1) is 2 ⁿ tracks including the total number of tracks TN in one recording zone. It is represented by the quotient divided by, or R _DB / R _B.

Further, the number of tracks outermost final recording zone Z _N-1 is expressed by the sum of the surplus when A is divided by 2 ⁿ tracks and the total number of tracks TN by 2 ⁿ tracks.

Here, the recording density (reciprocal number) d ₁ of the innermost circumference
Is represented by a value obtained by dividing the circumference of the innermost radius R ₁ , that is, 2πR ₁ by the product of the total number of bits per sector and the number of sectors K ₁ per track. In addition, the m-th optical disc (m
, 1, 2, ..., N-1, N), the radius R _m of the boundary position between the recording zone Z _m-1 and the previous recording zone is included in one recording zone at the innermost radius R _1. It is indicated by a value obtained by adding the product of 2 ⁿ tracks, the track pitch TP, and the number of recording zones (m-1).

A value larger than (the reciprocal of) the recording density d ₁ of the innermost circumference in the _m- th recording zone Z _m-1 of the optical disk obtained by dividing the data recording area into the number N of zones in this way, in other words, the innermost circumference. Maximum number of sectors that does not exceed the recording density of K
_m is represented by a quotient obtained by dividing the recording density of a recording track having a radius R _m from the center of the optical disk by the product of the total number of bits per sector. When this relationship is arranged, K _m = K ₁ × (R _m / R ₁ ) (6)

Using the above-mentioned symbols, the total recording capacity gradually increases as the number N of recording zones increases (the number of n bits indicating the number of tracks decreases). Therefore, the total recordable capacity is the maximum number of sectors K _m of the _m- th recording zone Z _m-1.
And the recording capacity in one sector and the product of the number of tracks in the recording zone 2 ⁿ , the sum of m = 1 to N, the maximum number of sectors K _{N in} the final recording zone Z _N-1 and the recording capacity in one sector. And the total number of tracks TN divided by the number of tracks for every 2 ^n, and the product of the total number of tracks TN and the number of fractional tracks.

A more specific embodiment of the present invention using the above principle will be described with reference to the optical disc and recording method shown in FIG. ISO / IE of the ISO standard mentioned above
The radius of the 5.25-inch optical disk of C DIS 10089 is R
The track pitch TP is configured to be 1.6 .mu.m with the section of 30 to 60 mm as the recording area. Therefore, the total number of tracks TN having the recording area width of 30 mm is 18751 tracks. The track pitch TP is 1.6 as the recording area.
It is composed of μm.

In this embodiment, the optical disk 20 is divided into two with the number of recording zones N = 2. In the first recording zone Z ₀ , the number of tracks is 8192 (= 2 ¹³ ) from the _0th track T ₀ to the 8192th track T _8191.
It is set on the track. Therefore, the second recording zone Z ₁ is composed of the remaining 10559 tracks. Boundary radius R ₂ of the second recording zone Z _1, since an innermost radius R ₁ = 30 mm from the optical disk center, to set the boundary ^{_{R 2 = 30 + 2 13 ×}} 1.6μm = 43.1mm Become.

In the divided optical disk 20, K ₁ = 17 sectors, which is the normal set number per track, is set in the recording zone Z ₀ of the innermost circumference of the recording area. Further, it can be seen from the equation (6) that the number of sectors K ₂ per track in the outermost recording zone Z ₁ of the recording area is K ₂ = 17 × (43/30) = 24.3 sectors.

The number of tracks included in one recording zone is 18751/2 = 9375.5 tracks.
In the outermost recording zone Z ₁ , the recording track in the circumferential direction is equally divided into the number of sectors K ₂ = 25. 1
The total recording bit number m _R per sector is 1 Kbyte = 10
It is set to 24 bytes.

The maximum recording density in the recording zone Z ₀ is 1.02 μm / bit when expressed by the reciprocal of the recording density. Similarly, the maximum recording density in the recording zone Z ₁ is 1.04 μm / bit when expressed by the reciprocal of the recording density. The number of bits in the sector having the maximum recording density is 1360 × 8 bits.

In this optical disc, the track pitch TP is set to 1.6 μm. The relationship between the relative tracking signal amount and the track pitch TP has the relationship shown in FIG. 5 at the laser wavelength λ = 780 nm. Here, if the relative tracking signal amount of about 0.5 or more is adopted for the optical disc as a standard, it is understood that the track pitch of 1.3 μm or more is in a range suitable for general use.

FIG. 6 shows the relationship between the recording density and the error rate. The relationship between the recording density and the error rate shown in FIG. 6 is as follows.
7 shows the case of the condition of 7 modulation. Under this condition, a bit length of 0.7 μm or more can maintain a sufficient error rate of 10 ⁻⁵ , so that the bit length at the laser wavelength is set as an appropriate recording density.

The present invention is not limited to the embodiment in which the above-mentioned 5.25-inch optical disc is divided in the radial direction, but is a 3.5-inch size according to the ISO CD 10090 standard of the International Organization for Standardization. The capacity of the recording medium can be similarly increased by applying it to the optical disc. For example, when the number of recording zones N = 2, the wavelength of the laser beam and the track pitch TP are the same, and the radius R _{1 of the} innermost periphery is R ₁ = 24 m
A large recording capacity can be secured by setting m and R ₂ = 40 mm.

If 1 Kbyte can be recorded in one sector by dividing the optical disk into recording zones as described above, the data recording capacity is the same as that of the conventional ISO / IEC DIS 1008.
9 Amount of data in the standard of 326M bytes is 402
It can be increased to M bytes. With the method described above, the number of recording zones divided for every 2 ⁿ tracks and the number of bits n (n is a natural number) can be arbitrarily selected. further,
The switching point of each divided recording zone is equal to the number of tracks above.
By switching for each number of tracks indicated by the power of
When a digital discrimination signal is used, switching control can be easily performed using, for example, the upper several bits. As described above, it is possible to enable large-capacity recording with an easy technique.

Further, a recording method for recording data on the optical disc will be described with reference to FIGS. 7 to 9.
FIG. 9 shows a case where recording is performed using the optical modulation method and the mark length recording method, and the width t between the zero-cross points with respect to the recording data read waveform is changed by changing the laser power at the time of recording or the magnitude of the external magnetic field. By changing, for example, when applying a power larger than normal strength,
Width t between zero-cross points from rising to falling
_S becomes larger than t (t <t _S ) and this may appear as jitter.

On the other hand, in the case of the light modulation method, the jitter can be suppressed by using the pit position recording method. This will be explained with reference to FIG. 7A.
In the recording data shown in (1), "0" is always inserted between the recording data "1" (see the recording waveform of FIG. 7B). At the time of recording, the optical modulation can be performed with the position of the duty of 50% of the recording data “1” in the recording waveform shown in FIG. 7B as the center position.

By recording in this way, when the peak position of the read waveform of the recorded data at the time of reading shown in FIG. 7C is detected, the width t _S that fluctuates depending on the laser power at the time of recording or the magnitude of the external magnetic field. Is the width t _S between the zero-cross points from the rising edge to the falling edge shown in FIG. 9C.
Width t between peak positions without depending on fluctuations such as
Can be as wide as (t = t _s), and outputs the same waveform as the waveform shown in FIG 7B, it is possible to solve the occurrence of jitter.

When the magnetic field modulation method is adopted,
Mark length (or edge) recording is preferred. this is,
The recording waveform shown in FIG. 8B is generated by inverting the previous level (mark length recording) according to the level change of “0” to “1” of the recording data shown in FIG. 8A. Magnetic field modulation is a method of changing the timing of rising and falling of a waveform according to the strength of magnetism. Therefore, in this magnetic field modulation, a phase shift occurs when the magnetic field strength changes, but the width t _S between the zero cross points is the same as the mark length (width between edges) t according to the recording data. Can be recorded in width.

By recording in this way, focusing on the rising and falling edges of the read waveform of the recording data at the time of reading shown in FIG. 8C, it varies depending on the laser power at the time of recording or the magnitude of the external magnetic field. the width t _S between zero cross points can be output to a mark length corresponding to the recording data as wide as the t (width between edges) (t = t _s) which,
It is possible to solve the occurrence of jitter.

As described above, a large recording capacity can be secured by dividing the recording area of the optical disk into 2 ⁿ tracks and providing a plurality of recording zones.
Switching control of each recording zone can be easily performed. Also, by considering the signal modulation method such as pit position recording or edge recording, accurate recording / recording can be performed on an optical disc with an increased recording capacity without causing jitter.
Playback can be performed.

[0045]

As is apparent from the above description, according to the optical disc and the optical disc recording method of the present invention, in an optical disc in which a plurality of recording tracks are recorded and formed, the recording area of the optical disc is 2 ⁿ ( (n is a natural number) is divided into a plurality of recording zones each having the same recording capacity per track in the same recording zone, and different recording capacities in different recording zones. By recording while making the linear recording densities of the zones substantially equal to each other, the recording capacity per surface can be significantly increased.

Further, the number of recording zones can be arbitrarily selected, and the degree of freedom is increased. In particular, by switching the switching point of each divided recording zone by the power of 2 of the number of tracks,
When the digital discrimination signal is used, the recording zone can be easily switched by using, for example, the upper several bits. As described above, it is possible to stably achieve large-capacity recording and reproduction with a simple technique.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the principle of an optical disc and a recording method for an optical disc according to the present invention.

2 is a graph showing the relationship between the number of divided recording zones and the recording capacity ratio of the optical disc in FIG.

FIG. 3 is a schematic diagram showing a specific example for explaining the principle of the optical disc according to the present invention.

FIG. 4 is a schematic view showing an embodiment of an optical disc according to the present invention.

FIG. 5 is a graph showing a relationship between a track pitch of an optical disc and a relative tracking signal amount.

FIG. 6 is a graph showing the relationship between the recording density of an optical disc and the error rate.

FIG. 7 is a diagram illustrating a recording method of recording on an optical disk by using an optical modulation method and pit position recording.

FIG. 8 is a diagram illustrating a recording method of recording on an optical disc by using a magnetic field modulation method and mark length (or edge) recording.

FIG. 9 is a diagram illustrating a recording method for recording on a conventional optical disk by using an optical modulation method and mark length recording.

[Explanation of symbols]

N ・ ・ ・ ・ ・ ・ ・ ・ Number of recording zones 2 ⁿ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Number of tracks included in one recording zone R ₁・ ・ ・ ・ ・ ・・ ・ ・ Radius of innermost circumference of recording area R ₂・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Radius of outermost circumference of recording area K ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Number of sectors TP ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Track pitch

Claims (2)

[Claims] 1. In an optical disc on which a plurality of recording tracks are recorded and formed, a recording area of the optical disc is divided into a plurality of recording zones having 2 ⁿ (n is a natural number) tracks, and in the same recording zone, The recording capacities per track are equal,
An optical disk characterized in that the recording capacities per track are made different in different recording zones, and the linear recording densities in the respective recording zones are made substantially equal to each other. 2. An optical disk recording method, wherein the recording area of the optical disk is divided into a plurality of recording zones having 2 ⁿ (n is a natural number) tracks, and the recording capacity per track is within the same recording zone. Equal to each other,
A recording method of an optical disk in which recording capacities per track are made different in different recording zones so that linear recording densities in the respective recording zones are made substantially equal to each other.