JPH04155662A - Disc recording medium - Google Patents

Abstract

PURPOSE:To increase recording capacity without increasing the scale of circuit by continuously recording address and data in data area with substantially constant line recording density. CONSTITUTION:In a recording medium 10, servo areas As and data areas Ad are disposed alternately along the rotational direction of disc, i.e. the direction of recording track, where a single area As and an area Ad adjacent thereto constitute a single segment SG. Each area As is previously arranged radially from the center of rotation Ro of a disc. An address such as so-called sector mark or a track address and predetermined number of data DA are recorded continuously using a predetermined channel clock obtained based on clock information of the area As. Reference and data are recorded continuously with substantially uniform line density in the area As, regardless of the track position, using the predetermined channel clock.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a disk recording medium, and particularly to a so-called disk recording medium in which recording areas for servo information such as a clock and tracking are formed intermittently in advance along the recording track direction. The present invention relates to a disk recording medium having a sample servo format.

B1 Summary of the Invention The disk recording medium according to the present invention is a disk recording medium in which servo areas and data recording areas are arranged alternately along the recording track direction, and the linear recording density is approximately constant in the data area. By recording addresses and data continuously, the recording capacity can be increased without requiring a relatively large circuit to detect addresses such as sector marks and track addresses. be.

C1 Conventional technology Servo areas (for example, about 1000 to 2000 per track) are formed discretely on the recording track of a disk, and servo information obtained from these discrete servo areas is used to create servo areas. A so-called sample servo format disk recording medium in which data is recorded or reproduced while clocking or tracking is conventionally known.

In this sample servo format disk recording medium, the servo areas within the shell are formed radially from the center of disk rotation so that adjacent tracks are at the same position, and the disk is moved at a constant angular velocity (CA).
Data is recorded or reproduced while being rotated by V).

In this case, the data recording capacity per unit track length of the disc, that is, the linear recording density, is highest on the innermost track and lowest on the outermost track, so the maximum data recording capacity of the disc is on the innermost track. This is determined by the upper limit of recordable linear recording density, and recording is performed at a linear recording density lower than the upper limit on the outer circumferential side.

Therefore, there is a problem that only a recording capacity lower than the original recording capacity of the entire medium can be achieved, resulting in poor utilization efficiency of the medium.

Therefore, for example, in the recording method for a small optical disc disclosed in Japanese Patent Application Laid-Open No. 1-204272, the recording track of the optical disc is divided into a plurality of blocks in the radial direction (so-called zoning), and the frequency of the tarokk for recording and reproduction is adjusted. By increasing the pro- tack on the outer circumferential side, data is recorded or reproduced at a substantially uniform linear density on the inner and outer tracks, thereby increasing the recording capacity.

D0 Problems to be Solved by the Invention Incidentally, a sector, which is a unit block for managing recorded data on a disk, is made up of a plurality of pairs (for example, several dozen) of the above-mentioned servo area and data area (this is called a segment). The first segment of each sector is an address segment in which a sector mark indicating the beginning of the sector, a track address, etc. (hereinafter referred to as reference) is recorded, and the second and subsequent segments are Data is now being recorded. Therefore, when zoning is performed as described above, the number of sectors that can be recorded in one track may not be an integer (a remainder appears), resulting in poor utilization efficiency.

Therefore, as shown in FIG. 3, for example, each sector (St.
,S! , . . . ) may be considered, but in this case, complex circuitry and software would be required to detect the sector marks.

In order to avoid such drawbacks, for example, as shown in FIG. 4, the arrangement of sectors SC consisting of references such as sector marks and track addresses and data DA is completed within a track, that is, one sector SC is divided into two sectors. The reference r
A disc recording medium is conceivable in which ef is arranged in one segment SG and data DA is arranged from the segment SG next to the segment SG where the reference ref is arranged, but as shown in FIG. The usage efficiency of the segment SG is poor, and as a result, the usage efficiency of the entire medium is poor.

The present invention has been made in view of the above circumstances, and is a sample servo format disk recording medium that does not require a relatively large circuit scale for detecting addresses such as sector marks and track addresses. The purpose of the present invention is to provide a disc recording medium that can increase recording capacity.

81 Means for Solving the Problems In order to solve the above problems, the present invention provides a disk recording medium in which servo areas and data recording areas are arranged alternately along the recording track direction. A special F9 operating book characterized in that addresses and data are formed in advance so as to be arranged radially from the center of rotation, and that addresses and data are continuously recorded in the data area at substantially uniform linear density on the inner and outer circumferential tracks. In the disc recording medium according to the invention, by making addresses such as sector marks and track addresses and recording data have a substantially uniform linear density regardless of the track position, the recording capacity of the entire disc is increased, and the addresses can be divided into servo areas. By placing it immediately after , address detection becomes easier.

G. Embodiment Hereinafter, an embodiment of the disk recording medium according to the present invention will be described with reference to the drawings.

In this embodiment, the present invention is applied to an optical disk recording medium. For example, as shown in FIG. 1, in the optical disk recording medium IO, servo areas As and Data areas Ad are arranged alternately, and one servo area As and continuous data areas Ad constitute one segment SG. Each servo area As is formed in advance (so-called preformat) so as to be arranged radially from the disk rotation center R8. Then, using a predetermined channel clock obtained based on the clock information of the servo area As, addresses such as so-called sector marks and track addresses (hereinafter referred to as reference ref) and a predetermined number of data D
A is recorded continuously.

Here, the above-mentioned predetermined channel clock is a frequency f obtained by converting the frequency f of the servo clock obtained by reproducing the clock information of the servo area As by M/N times, (=
f, XM/N), and the frequency conversion ratio M/N
changes depending on the recording track number of the optical disc, that is, the position in the radial direction. By setting this frequency conversion ratio M/N to be small on the inner circumferential side and large on the outer circumferential side, the channel clock is made low on the inner circumferential side and high on the outer circumferential side. The recording density is made to be approximately uniform. That is, the reference ref and data DA are recorded or reproduced in each data area Ad of the recording track using the frequency-converted channel clock. Therefore, as shown in FIG. 1, for a sector SC with a fixed number of bytes consisting of the reference ref and data DA, the number of segments used will be different between the inner sector SC and the outer sector SC. , this can be solved by managing using the reference ref recorded immediately after the servo area As.

Specifically, for example, in a 3.5-inch magneto-optical disk, the radius of each of the outermost and innermost tracks is 40 mm.
．． 0mm, 20.0mm, and 11024 between them
The book tracks are arranged at a pitch of 45 μm.

Furthermore, each track is provided with 1344 segments. Further, the servo area As of each segment has a capacity of, for example, 5 bytes, and this servo area As includes so-called wobble pits PA and P for tracking servo.
, a so-called clock pit PC for clock reproduction, two pits PE, PF, etc. for so-called gray code for performing track jumps, etc. are formed (preformatted) in advance. The data area Ad following this servo area As has a capacity of, for example, 20 bytes of a channel clock on the innermost track, and this data area Ad has a capacity of, for example, 15 bytes of sector marks, track addresses, etc. 600 bytes (total of 512 bytes of user data and redundant code)
data is continuously recorded using a predetermined channel clock so as to have a substantially uniform linear density regardless of the track position.

That is, the above-mentioned wobble ping (PA) in the reproduced RF signal,
Tracking servo is applied so that the difference in the detected intensity of Pl becomes 0. Furthermore, since there are 25 bytes of channel pits on the innermost track between the clock pits Pc in the servo area As, the detection period of the clock pits PC is set to 200 (=8X2
5) A signal with a predetermined frequency f1 to be divided is converted into a basic clock φ1.
Then, the frequency f of this basic clock φ1 is converted to M/N times the frequency f! (= f + x M/N)
clock φ.

Reference and data are recorded and reproduced using this as a channel clock. At this time, the frequency conversion ratio M/N is determined according to the disk radial direction.

Next, a comparison of the recording capacities of the disk recording medium to which the present invention is applied (hereinafter referred to as type 1) and the disk recording medium shown in FIG. 4 (hereinafter referred to as type 2) will be explained.

Here, in the same way as described above, for example, 3 disc recording media are used.
．． A 5-inch magneto-optical disk was used, and various parameters such as recording modulation method, track pitch, and number of bytes of data in one sector were set as shown in Table 1.
(Margins below) Table 1 Then, if the recording capacity of the l segment is N, (20 bytes on the innermost track, and increases toward the outer tracks), type 1 disk to which the present invention is applied Since references and data are recorded continuously on a recording medium, the number of segments N required to record one sector of references and data is: N+=round up ((N5c in Na)/N5c)
). Here, rround Lll)J means rounding up the decimal point to make an integer.

On the other hand, in a type 2 disk recording medium, one segment is allocated to the reference and data is recorded in multiple segments, so the number of segments required to record one sector of reference and data is N! is, N @ = 1 + round up (N sc/
N5a)=round up((Naa+N*c)/
N5a)). By the way, the segment capacity N0 is larger than the reference byte number Nヮ (N0≧N),
Therefore, the recording capacity of the type I disk recording medium to which the present invention is applied is larger than that of the evening/eve 2 disk recording medium.

Specifically, the maximum number of sectors that can be recorded on the outermost track under the conditions of recording at the shortest pitch interval or more is determined,
It is determined to which track on the inner circumferential side the number of sectors can be secured, and the area up to that limit track is defined as one area (zone). Then, the above operation is repeated from the next track to perform zoning of the disc recording medium. For example, if 11 zoning is performed and the recording capacities of the type 1 disk recording medium and the type 2 disk recording medium are compared, the results shown in Tables 2 and 3 are obtained. For example, in a type I disk recording medium, in zone number 0, the number of tracks that can secure 66 sectors is 17.
66, and the recording capacity of the user in that zone is 56.
9 MB (=66X 1766X 512/1024
It becomes (Margin below) Table 2 (Type 1
) (Margin below) Table 3 (Type 2) As is clear from these Tables 2 and 3, for example, in zone number 0, on a type 2 disk recording medium, the number of tracks that can record 66 sectors is 1104, whereas in the type I disk recording medium to which the present invention is applied, the number of tracks on which 66 sectors can be recorded is 17.
It becomes 66. Also, for example, in zone number 7.8,
With type 2 disk recording media, the number of sectors that can be recorded on one track is 47.45, whereas
In the type I disk recording medium to which the present invention is applied, l
The number of sectors that can be recorded on each track is 49.47. As a result, the recording capacity of the entire medium is 287.4 MB for the type 2 disk recording medium, whereas the recording capacity of the entire medium is 293 MB for the disk recording medium to which the present invention is applied.
．． 2MB, making it possible to increase the recording capacity of the disk recording medium compared to the conventional one.

Furthermore, the recording capacity of each type of disk recording medium when the number of zones is changed is as shown in Table 4.

(Left space below) Table 4 In other words, in any zoning, the type I disk recording medium to which the present invention is applied can have a larger recording capacity than the type 2 disk recording medium.

Next, reference is made to FIG. 2 for a specific example of an optical disc recording/reproducing apparatus for recording or reproducing data on a data area Ad on any track of the optical disc recording medium (hereinafter referred to as an optical disc) 10. I will explain.

In FIG. 2, an optical disc 10 is rotationally driven at a constant angular velocity (CAV) by a spindle motor 20.
As the disk rotates, the optical head 21 rotates the optical disk 1.
Data is recorded or reproduced optically (or magneto-optically) by scanning 0 with a laser beam.

Inside the optical head 21, there is a laser light source that is driven by a laser drive circuit 22 to output a laser light for data recording and reproduction, and a photode for detecting the reflected light of the laser light from the laser light source by the RADISC IO.

Tekta etc. are provided. C playback R from optical head 21
The F signal is supplied from the first preamplifier 23 of the data reproduction processing system to the digital equalizer 25 via the A/D (analog/digital) exchanger 24, where it is subjected to equalization processing, and then sent to the decoder 26. Reproduction digital data D. It is decoded and displayed as U. In addition, the reproduction RF (j number) is supplied from the second front expansion wall 27 of the servo information reproduction processing system to the head servo circuit 28 and the spindle servo circuit 29, and is also supplied to the clock recirculation circuit 30. ing.

The head servo circuit 28 is connected to the front gl12 in the optical head 21.
The axis actuator is driven and controlled to perform tracking servo and focus servo.

That is, this head servo circuit 28 detects a tracking error based on the reproduced output of the tracking double pits PA, P, and performs tracking servo control on the servo area tAs.
Orcus servo control is performed using the reflective surface portion without pits. Also, spindle servo) circuit 2
9 detects the rotation angle error of the spindle motor 20 based on the reproduction output of the clock bit PC described above, controls the motor drive circuit 40, and controls the rotation of the spindle motor 20, thereby controlling the optical disc 10.
Spindle servo control is performed so that the spindle rotates once at a constant angular velocity (CAV).

Next, the clock regeneration circuit 30
The regenerated RF signal obtained through the preamplifier 27 from
It is composed of a PLL circuit that is synchronized with the clock pit PC detection pulse in the bone and outputs a basic clock φ1 of 200 times the frequency (the frequency f). The basic clock φ from this clock regeneration circuit 30
1 is sent to a frequency conversion circuit 50 using a PLL circuit or the like. Further, the basic clock φ is sent to the head servo circuit 28 and the spindle servo circuit 29, respectively.

The frequency conversion circuit 50 converts the frequency f1 of the basic clock φ from the clock regeneration circuit 30 into a frequency f1 times M/N,
This frequency conversion ratio M/N is controlled by the system controller 41 so as to change depending on the track address of the track being scanned by the optical head 21. That is, the frequency conversion circuit 50 includes a first programmable divider that divides the input basic clock φ1 into 1/H, and a PLL circuit system 70.
A second programmable divider that divides the 0 oscillation output (frequency f, = f, XM/N) into 17M is provided, and the phase difference between the output signals from these two programmable dividers is set to 0. A clock φ having a frequency f is obtained by PLL control. The division ratios of each of these programmable dividers, 1/N and 1/
M is the control data DN from the system controller 41
.

D, is variably controlled. When the scanning track of the optical head 21 is on the inside, the conversion ratio M/N is decreased to keep the frequency f low, and as the scanning track is on the outside, M/N is increased to keep the frequency f! By increasing the
The linear recording density on the optical disk 10 is controlled so as to be substantially uniform on all tracks.

In this way, the frequency f! depends on the radial position (track address) of the recording track! Frequency conversion circuit 50
The clock φ from the channel clock φ is sent to the phase control circuit 60 as a channel clock. This phase control circuit 60 outputs a clock for operating the A/D converter 24, equalizer 25, etc. Further, the clock φ from the frequency conversion circuit 50 is sent as a channel clock to the encoder 42 of the data recording system. In the recording mode, the encoder 42 converts input references such as sector marks and track addresses, and recording data D18 into recording timing pulses synchronized with the clock φ, and supplies the pulses to the laser drive circuit 22. ing.

Here, in both the data recording mode and the data reproduction mode, in order to access the track on the optical disc 1o, it is necessary to read the track address of the sector, since it is recorded immediately after the servo area. Track addresses can be detected using a circuit with a relatively simple configuration.

As described above, in the disk recording medium to which the present invention is applied, as shown in FIG. 1, the servo area As and the data area Ad are arranged alternately along the recording track direction, and the servo area As is The data area Ad is formed in advance so as to be arranged radially from the center of rotation, and references such as sector marks and track addresses and data are continuously recorded in the data area Ad at a substantially uniform linear density on the inner and outer circumferential tracks. Therefore, the recording capacity can be increased without increasing the circuit scale for detecting the reference.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, various magneto-optical disks, write-once optical disks, etc. can be used as the optical disk IO. In addition, the device that records or plays back on the optical disc recording medium has a second
Of course, the present invention is not limited to the illustrated example.

H9 Effects of the Invention As is clear from the above explanation, in the present invention, in a disk recording medium in which servo areas and data recording areas are arranged alternately along the recording track direction, the servo areas are arranged radially from the center of rotation of the disk. Addresses and data are continuously recorded in the data area at approximately uniform linear density on the inner and outer tracks, thereby detecting addresses such as sector marks and track addresses. It is possible to increase the recording capacity without increasing the circuit scale required for recording.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a schematic configuration of an optical disc recording medium to which the present invention is applied, and FIG. 2 is a block diagram showing an example of a device for recording or reproducing data on this optical disc recording medium. FIG. 3 is a plan view showing a schematic configuration of a disk recording medium in which references and data such as track addresses of each sector are continuously arranged regardless of the servo area, and FIG. FIG. 3 is a plan view showing a schematic configuration of a disk recording medium in which a reference such as . 10... Optical disk recording medium As... Servo area Ad... Data area SG... Segment SC... Sector ref... Reference DA... Data Figure 1

Claims (1)

[Claims] In a disk recording medium in which servo areas and data recording areas are arranged alternately along the recording track direction, the servo areas are formed in advance so as to be arranged radially from the center of rotation of the disk, A disk recording medium characterized in that addresses and data are continuously recorded in the data area at a substantially uniform linear density on the inner and outer tracks.