JPH0434766A - Recording medium and recording medium driver - Google Patents

Abstract

PURPOSE:To prevent disabled control due to disabled address detection by recording/reproducing a data including a pre-format data other than a sector mark with a clock different from each sector and recording the sector mark over the entire sectors with a same clock and a same pattern. CONSTITUTION:A sector mark is recorded over all sectors of a recording medium 1 by a same clock and a same pattern. Thus, even in the case of the MCAV (modified Constant Angular Velocity) system, sector marks SM of all sectors are surely detected, the recording medium 1 is used to detect the sector mark SM by using a reproduced clock to count the sector marks SM detected during one revolution thereby discriminating an accessed sector area and a recording/ reproducing clock in response to the discriminated sector area. Thus, even when a zone different from an object zone is accessed and address information cannot be detected, the accessed zone is correctly detected, the address information during access is detected and disabled control of the device is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to recording media such as optical disks and magnetic disks and their drive devices, and in particular to MCAV (Modifier).
tlConstant Angular Veloc
icy) formatted recording medium and its drive device.

[Conventional technology]

Conventionally, CAV (Constan
tAngular Velocity) method and CL
V (Constant Liner Velocity)
There were two types of methods. In the CAV method, recording/reproducing operations are performed at a constant rotational speed, and in the CLV method, recording/reproducing operations are performed at a constant circumferential speed. Therefore, in the case of the CAV system, the recording density at the outer circumference of the disk is lower than that at the inner circumference, resulting in a problem that the recording capacity becomes smaller.

In contrast, in the CLV method, the rotational speed is lowered toward the outer periphery, so the recording density remains approximately constant, and the recording capacity can be increased by approximately 50% compared to the CAV method. However, since the CLV method requires changing the rotational speed in the radial direction, there is a problem that the seek time is longer than that of the CAV method.

A new MCAV method has been proposed to solve these problems.

In the MCAV method, like the CAV method, recording/reproducing operations are performed at a constant rotation speed, and the recording/reproducing clock is changed for each annular zone consisting of a fixed number of tracks, and the recording density is changed by changing the number of sectors. It is something. That is, the number of sectors increases toward the outer zone. As a result, the recording capacity can be increased compared to the CAV method, and the seek time can be shortened compared to the CLV method.

On the other hand, the ISO has established standards for 130+u+ optical discs. The ISO adopts the CAV method, and for example, when the user data area is 512 bytes, the format is shown in FIG. 4. That is, one sector is 746 bytes, of which the first 52 bytes are a preformatted part,
Other areas are non-preformatted data portions including a 512-byte user data area. The first 5 bytes of the preformat part are the sector mark SM indicating the beginning of the sector, followed by P.
A 12-byte VFOI for LL pull-in, a 1-byte address mark AM indicating that there is address information, an address information ID such as a trunk number and a sector number, and a CRC for error detection are formatted into 5 bytes.
Next, two sets of 8-byte vpo, 1-byte AM, and 5-byte ID and CRC are made. Therefore, 10 is written in triplicate. sector mark SM
is recorded in a unique binary pattern consisting of a plurality of consecutive 1's and 0's, and other data is recorded in a (2-7) modulation code. Further, one round is divided into 31 sectors.

[Problem to be solved by the invention]

FIG. 4 is a format diagram when the ISO format is applied to the MCAV method, and the vertical axis shows the zone from AO to Aj, and the horizontal axis shows the time domain. As shown in FIG. 5, in zones A0 to A, the recording/reproducing clocks including sector marks are the same, and the time domains are the same. However, this differs between zones, so when accessing across zones, if the destination zone is incorrect,
There is a possibility that the sector mark, address mark 10, etc. cannot be detected using the reference clock for the target zone that is preset in hardware.

In particular, when the position of the optical head is recognized by address detection rather than a scale, if the address, 10, etc. cannot be detected, the position of the optical head cannot be recognized and the subsequent sequence cannot be performed, and the optical disk drive device is controlled. There is a risk that it will become impossible.

The present invention has been made in view of the above circumstances, and provides a recording medium and its recording medium that can accurately detect sector marks even in the MCAV method by recording sector marks in the same period and in the same pattern over all sectors. By detecting sector marks on the medium using the same reproduction clock, counting the number, and determining the zone based on the number, other data including address information within the zone can be generated using the corresponding reference clock. It is an object of the present invention to provide a recording medium drive device that can reliably read data and prevent loss of control due to address inability to be detected.

[Means to solve the problem]

The recording medium according to the present invention records/reproduces data including preformat data other than sector marks using a different clock for each annular area, and records sector marks with the same clock and the same pattern over all sectors. A recording medium drive device according to the invention detects sector marks using a clock for reproducing sector marks, and determines an annular area by counting the number of detected sector marks.

[Effect]

In the present invention, in the recording medium, only sector marks are recorded with the same clock and the same pattern over all sectors, and other data including address data is recorded/reproduced with different recording/reproducing clocks for each annular area. Therefore, if an error occurs during data recording/reproduction, the drive device for this recording medium reliably detects the sector mark using the sector mark reproduction clock during a retry attempt, and determines the annular area based on the number and rotation speed of the sector mark. Data including address data can be correctly recognized by the recording/reproducing clock corresponding to the annular area.

〔Example〕

Hereinafter, the present invention will be explained based on drawings showing embodiments thereof.

FIG. 1 is a schematic diagram of the format of an optical disc, which is a recording medium according to the present invention. For example, the optical disc l is 130
mm diameter, and for example, more than 18,000 spiral track grooves are formed therein. Also, the optical disc 1 is arranged from A0 to A from the inner circumferential side to the outer circumferential side.
+1 (for example, j=31) zones are formed.

The innermost zone A0 is divided into O-n n+1 (for example, n=30) sectors in the circumferential direction, and the number of sectors increases by 1 toward the outer zone. , n+l+j (for example, 62) sectors are formed. Therefore, the number of trunks in one zone is, for example, 18,000/31 #580. Further, one sector is a 746-byte area that conforms to ISO standards and includes, for example, a 512-byte user data area, and a sector mark SM is formed at the beginning of the sector to indicate that it is the beginning of the sector.

FIG. 2 is a diagram schematically showing the format of sector marks in each zone A0 to Aj of the recording medium of the present invention, with the zones A0 to A being plotted on the vertical axis and the time domain being plotted on the horizontal axis. The sector marks SM of the optical disc 1 are in the same time area in all sectors. The pattern recorded as the sector mark SM is a pattern based on ISO, and for example, 1 in all zones A0 to Aj.
Recorded using the same 5MHz clock. Further, the preformat M area and other data areas other than the sector mark needle are recorded/reproduced using different recording/reproducing clocks for each zone. Therefore, the time domain of these regions becomes shorter toward the outer periphery (upward in the figure). For this reason, for example, in the outermost zone, the recording/reproduction clock excluding the sector mark needle is, for example, 30 MHz, and in the innermost zone, it is 15 MHz.

Which zone A0 to A is the sector mark SM of the optical disc 1?
, even in all zones A0 to A by recording with the same pattern and the same clock.

At least the sector mark needle can be reliably detected.

In contrast, in the optical disc using the conventional MCAV format shown in Figure 4, the recording/reproducing clock for the sector mark SM is different for each zone A0 to A, just like other areas, so it is possible to access the wrong zone. If this occurs, data including sector mark hands cannot be reproduced and there is a risk of loss of control.

Next, the recording medium drive device of the present invention will be explained.

FIG. 3 is a block diagram showing the configuration of an optical disk drive device which is a recording medium drive device according to the present invention.

In the figure, the disk is an optical disk formatted according to the MCAV method and on which sector marks SM are recorded with the same clock and the same pattern, and has the format shown in FIGS. 1 and 2. The optical disk 1 is rotated by a motor 2 at a constant rotation speed (for example, 2400 rpm). An optical cover 3 is provided below the optical disc 1 for accessing it with a laser beam. The optical disc 3 irradiates the optical disk 1 with a laser beam, receives the reflected light, and reproduces information recorded thereon. In addition, in the case of a magneto-optical disk drive device, a magnet (
(not shown), and the optical head 3 irradiates the optical disc 1 with a laser beam of higher power during recording and erasing than during reproduction.

The reproduced signal is given to the sector mark detection circuit 4 and (2-7) data detection circuit 10. The sector mark SM and other data are recorded with a different modulation code, and the sector mark S? Data other than 'l' is recorded according to the (2-7) modulation code, and the sector mark SM is recorded with a pattern conforming to ISO.

Therefore, a separate device for detecting sector marks is required. The sector mark detection circuit 4 and (2-7) data detection circuit 10 pre-process analog playback signals for A/D conversion, and the sector mark detection circuit 4 detects consecutive 1 or O edges. Similarly, (2-7) the data detection circuit 10 includes (2-7) a differentiation circuit that detects edges of modulation codes. The sector mark detection signal detected as binary data by the sector mark detection circuit 4 is given to the sector mark determination circuit 5. The sector mark determination circuit 5 is given the above-mentioned recording/reproducing clock (for example, 15 MHz) generated by the reference clock generator 14, samples the reproduced signal using that clock, and compares it with a sector mark pattern stored in advance. It is determined whether or not it is a sector mark.

(2-7) The data detection signal detected as binary data by the data detection circuit 10 is provided to the data separator 11. The data separator 11 is also supplied with a zone recording/reproducing clock from a variable clock generation circuit 13 that generates a zone recording/reproducing clock for each zone from 15 MHz to 30 MHz based on a reference recording/reproducing clock. The data separator 11 is synchronized with the zone recording/reproduction clock in the non-read state.

Furthermore, the data separator 11 is synchronized with the data detection signal in the read state. Then, a CO clock synchronized with the data detection signal and a data detection signal reshaped by the vCO clock are output. Further, the variable clock generation circuit 13 generates a zone recording/reproduction clock for each zone based on commands from the microcomputer 9, that is, zone information determined by the microcomputer 9 based on access information.

The zone recording/reproducing clock is also applied to the address detection gate generation circuit 6 along with the determination result of the sector mark determination circuit 5. The address detection gate generation circuit 6 generates a gate signal for reproducing the next recorded address information based on the determination that the sector mark SM has been detected, and the generated gate signal is sent to the address detection circuit 1.
given to 2. The address detection circuit 12 determines the data detection signal from the data separator 11 using the vCO clock at the timing when the gate signal is input, reads the track number and sector number from 10, and outputs address information to the microcomputer 9. microcomputer 9
recognizes the position of the optical head 3 based on the given address information, calculates the number of tracks accordingly when the access information is given, controls the optical head 3 by a drive circuit (not shown), and also reads the zone information as described above. is output to the variable clock generation diagram lR13.

If the address detection circuit 12 fails to detect address information, the microcomputer 9 estimates the address based on the most recently detected address information, and outputs zone information based on the estimated address to the variable clock generation circuit 13. As a result, if the address information cannot be detected a predetermined number of times, the microcomputer 9 outputs an address detection impossible signal indicating this to the address detection gate generation circuit 6. When the address detection gate generation circuit 6 receives the address detection impossible signal from the microcomputer 9, it outputs a sector mark detection signal to the sector mark counting circuit 7. The sector mark counting circuit 7 counts the number of times sector marks are detected per revolution based on the number of rotations, and provides the counting result to the zone determination circuit 8. The zone determination circuit 8 determines which zone is being accessed by the optical radar 3 based on the counting result, and outputs the determination result to the microcomputer 9.

With this configuration, if the address information cannot be detected for a predetermined number of times or more, the zone can be determined based on the number of detected sector marks, and the address information can be reliably detected using the zone recording/reproduction clock based on the detected number of sector marks.

In the above embodiments, a 13011I11 optical disk and its drive device were explained as an example, but the present invention is not limited to this, and can be applied to other recording media such as optical disks and magnetic disks of any diameter and their drives. Needless to say, it can also be applied to devices.

In addition, the standard recording/reproducing clock was set to 15 MHz, and the zone recording/reproducing clocks for the innermost and outermost circumferences were 15 MHz and 30 MHz in the above embodiments, but this is just an example, and the zone recording/reproducing clock may be windowed appropriately depending on the radius ratio.

〔Effect of the invention〕

As explained above, in the present invention, sector marks are recorded with the same clock and the same pattern over all sectors in the recording medium, so even if the MCAV method is used,
Sector marks of all sectors can be detected reliably, and
Using the recording medium, by detecting sector marks using a reproduction clock and counting the detected sector marks during one rotation, it is possible to determine the annular area being accessed, and record according to the determined annular area. / Since a regenerated clock is generated, even if a zone different from the target zone is accessed and the address information cannot be detected, the accessed zone can be correctly determined, the address information being accessed can be detected, and the device This has excellent effects such as preventing the system from becoming uncontrollable.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the format of an optical disc, which is a recording medium according to the present invention, FIG. 2 is a diagram schematically showing the format of sector marks in each zone, and FIG. 3 is a diagram of a recording medium drive device according to the present invention. Block diagram showing the configuration, Figure 4 is 1
50 standard formant diagram, Figure 5 is the ISO standard MC
FIG. 2 is a schematic diagram showing a format of a sector mark when applied to an AV system. DESCRIPTION OF SYMBOLS 1... Optical disk 3... Optical head 5... Sector mark judgment circuit 6... Gate generation circuit for address detection 7... Sector mark counting circuit 8... Zone judgment circuit 9... Microcomputer 14...
Reference clock generator SM: Sector mark In the drawings, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Diagram 1: Optical disc SM: Sector mark diagram

Claims (2)

[Claims] (1) A recording medium in which an address is specified by a track provided in a spiral or annular shape, and a plurality of sectors that divide the track in the circumferential direction and have a different number for each annular area consisting of a predetermined number of tracks. A recording medium characterized in that a sector mark indicating the beginning of a sector is recorded in the same clock and in the same pattern over all sectors. (2) A recording medium drive device for driving the recording medium according to claim 1 at a predetermined rotational speed and accessing each of the annular areas with a different clock, comprising means for generating a clock for reproducing the sector mark; means for detecting the sector mark based on the generated reproduction clock; means for counting the detected sector marks; and means for determining the annular area being accessed based on the rotational speed and the number of sector marks counted. A recording medium drive device comprising: