JPS626465A - Data recording system - Google Patents

Abstract

PURPOSE:To improve the recording efficiency of an optical disk by omitting the upper digits of sector addresses arranged on a preformat area to suppress the size of the preformat area. CONSTITUTION:In optical head 13 positioning control (rough positioning control) executed by a linear motor driving part 20 while referring a moving pulse outputted from a pulse encoder 19, about + or -0.1mm positioning error from a home position appears. Thereby, the optical head 13 can be positioned on an objective sector by executing a accurate positioning control by a track jump control part 24 while detecting the sector address of practically positioned sector to remove the positioning error based upon the rough positioning control. Since the positioning error of the crude positioning control is about + or -0.1mm and about 2048 sectors exist in the range, the upper digits corresponding to the 2048 sectors are omitted and only the lower digits of 0-2047 are assigned to the sector addresses.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a frame synchronization detection device that can reliably detect frame synchronization in a recording device having a data recording format in which data is recorded in a frame structure.

[Prior Art] Devices using magnetic recording media such as magnetic tapes and magnetic disks are widely used as auxiliary storage devices in computer systems. There have been proposals to use optical recording media (for example, optical discs) that can be used as auxiliary storage devices.

For example, in the case of an optical disc, a laser spot with a diameter of 1
Two micrometer-sized pits (small holes) are placed on the recording track on the surface.
Data is recorded by forming them at a period (interval) of approximately μm, and the storage capacity is 1 per sheet with a diameter of approximately 30 cm.
011 to 1OL2 bits, an example of which is shown in FIG.

In the figure, this optical disk 1 has recording tracks formed in concentric circles and is rotated at a constant angular velocity to record and reproduce data.
A clamp hole 1a for the drive device to hold the optical disc 1 is formed in the center, and a clamp hole 1a is formed at the center of the clamp hole 1a for the drive device to hold the optical disc 1.
A data recording area 1b is formed.

Now, since the access speed of auxiliary storage devices is generally much slower than that of main storage devices, data is recorded in blocks of a certain amount in consecutive areas.

At that time, to ensure that data can be read and written in a short time, predetermined blocks of data are organized into sectors,
Each sector is identified by assigning an address (sector address).

FIG. 5 shows an example of a data recording format in a track of the optical disc 1. As shown in FIG.

In the figure, in the track TH, sectors SC consisting of a preformat area PF, a data area DF, and a gap GPI separating the preformat area PF and the data area DF are continuously arranged for a predetermined number of sectors separated by a gap GP2. is set to

Further, as shown in FIG. 6, the preformat area PF includes a synchronization signal BS for matching circuit conditions, that is, a bit synchronization signal BS for synchronizing the bit clock of the data write/read circuit with the generation timing of recording data;
It consists of a sector synchronization signal SS consisting of a bit string (pattern) with sharp autocorrelation for detecting this preformat area 1dPF, and a sector address SA for identifying the sector SC.

The bit synchronization signal BS forming the preamble is a PLLP-hasa signal for extracting the P1-clock and data based on the readout signal from the optical pickup unit.
A signal is used that allows the Locked Loop circuit to be properly locked. For example, a signal that changes the state of successive signals with a minimum reversal period (i.e., a roioto signal in which the recording state on the previous disk is a repetition of the minimum pit length)
i...'').

In addition, the preformat area PF is spaced several times apart in advance from the data area DF and the gap GP2 to Pi1,
It is formed on the track TH. For example, when manufacturing the optical disc 1, a pattern corresponding to the preformat area MPF is formed in the pregroove in which the track TR is set.

By the way, since the optical disc l mentioned above is of the CAV system, as shown in FIG. 4, in the state before data is written, the preformat area PF is
is observed in a radial pattern. Further, the number of sectors per track TR on this optical disc 1 is 24.

Now, when recording data in such a recording format, assuming that radius R1 is 15c11, radius R2 is 30cm, and track spacing is 2μ..., the total number of tracks TR in recording area 1b is TrN.

TrN=(R2-RL) Umbrella 10-"/2 Umbrella 10-"=7
, 5000. Therefore, the recording area 1b of this optical disc 1
The total number of sectors in is MxS=7.5000
剟24 = 1,800,000.

Since it is necessary to identify a huge sector in this way, the number of digits in the security address SA becomes correspondingly large, and under the above conditions, the number of digits in binary number is 21 bits. Requires.

Incidentally, although optical disks have a significantly high recording density as described above, they are considered to be quite susceptible to bit error rates, rotational fluctuations of the drive system, and the like.

Furthermore, when accessing data, the target sector is accessed by referring to the information recorded in the preformat area PF, so in order to reliably reproduce the recorded data, it is necessary to We need to improve our sexuality.

Therefore, normally, as shown in FIG. 6, a plurality of bit synchronization signals O3, sector synchronization signals SS, and sector addresses SA are arranged to configure the preformat area 1 to area PF, thereby ensuring that the preformat area PF is I made it possible to detect it.

However, as described above, since the number of digits of the sector address SA is very large, the ratio of the preformat 1 and the area PF to the recording area 1b becomes large.

As a result, a problem arises in that the recording efficiency of the optical disc 1 is reduced.

[Objective] The present invention was made to solve the above-mentioned disadvantages of the conventional technology, and an object of the present invention is to provide a data recording method that can improve the recording efficiency of an optical disc.

[Structure] In order to achieve this object, the present invention suppresses the size of the preformat area by omitting the upper digits of the sector address arranged in the preformat area. Furthermore, the number of digits of the sector address is set in accordance with the positioning accuracy of a recording and reproducing mechanism that records and reproduces data on the optical disc.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an optical disk drive device according to an embodiment of the present invention. In the figure, a disk motor 10 rotates an optical disk 1 at a predetermined rotational speed (constant angular speed), and a clamp The mechanism 11 moves the optical disc 1 to a disc motor 10.
It is connected to the shaft of

The semiconductor laser 12 outputs a laser beam for recording and reproducing data on the recording surface of the optical disc 1, and the laser beam is used to drive an optical head 13 and a winding lens 14, which are comprised of an optical system and the like. The reflected light from the recording surface is transmitted through the aperture lens 14 and the optical head 13 to a sensor section 15 consisting of a photosensor, etc., which detects tracking errors, focusing errors, and signal light. guided by.

Note that a write signal Sv is applied to this semiconductor laser 12 from a data generation circuit (not shown), so that its output laser beam is modulated by the write signal Sv.

The aperture lens 14 is moved in the tracking direction and the focusing direction by an actuator 16, and this actuator 16 is controlled by a servo circuit 17 to which an error signal SE output from the sensor section 15 is applied. Thereby, the laser beam is accurately positioned on the recording track of the optical disc 1, and the focus of the aperture lens 14 is adjusted.

Also, a semiconductor laser 12, an optical head 13, an aperture lens 1
4. The sensor section 15 and the actuator 16 are integrally constructed and are moved in the radial direction of the optical disc 1 by a linear motor 18 .

A pulse encoder 19 is attached to the linear motor 18, and each time the linear motor 18 moves a predetermined distance,
A movement pulse MP is output from the pulse encoder 19,
This movement pulse MP drives the linear motor 18 or is output to the linear motor drive section 20.

The linear motor drive unit 20 drives the linear motor 18 until the input count value of the movement pulses matches a predetermined movement pulse number PM (described later).

The read signal SR output from the sensor unit 15 is applied to a sector address detection unit 21 that detects the sector address SA and a data reproducing circuit (not shown), and the sector address detected by the sector address detection unit 21 is SA is output to microprocessor 22.

A microprocessor 22 controls each element of this optical disk drive, and data is exchanged with external devices via an interface circuit 23.

The track jump control section 24 also includes a servo circuit 17.
to 1 with the ranking control turned off and the aperture lens 1.
This is to execute precise positioning control (hereinafter referred to as fine positioning control) in which the positioning unit 4 is moved one track at a time by the number of moving tracks TM (described later).

Now, in such an optical disk drive device, the microprocessor 22 controls the linear motor drive section 20 and the track jump control section 24 so as to position the laser spot at a target sector instructed by an external device.

First, the microprocessor 22 calculates the distance between the target sector and the current position (usually the home position), that is, the amount of movement MV (described later) of the optical head 13, and calculates the number of movement pulses PM corresponding to this. The pulse number PM is output to the linear motor drive unit 20.

Thereby, the linear motor drive unit 20 drives the linear motor 18 by the number PM of movement pulses given as described above.

At this time, in the positioning control (hereinafter referred to as coarse positioning control) of the optical head 13 performed by the linear motor drive section 20 with reference to the movement pulse MP output from the pulse encoder 19, the positioning error from the home position is, for example, ±0.
．． Approximately 1mm of roughness will occur.

Therefore, the positioning error caused by this coarse positioning control is eliminated by executing fine positioning control by the track jar ramp control section 24 while detecting the sector address SA of the sector where the sector is actually located.

The optical head 13 can be positioned at the target sector.

In this way, it is not necessary to refer to the sector address SA in the coarse positioning control, and therefore, in order to position the optical head 13, it is necessary to assign the sector address SA within the range of movement in the fine positioning control. Bye.

That is, in the coarse positioning control, the microprocessor 22 can determine the approximate position of the optical head 13 in units of the range of positioning error, so the position of the sector can be determined within the range of the positioning error. It is sufficient to add an address.

Therefore, in this embodiment, as described above, the positioning error in coarse positioning control is about ±0.1 mm, and there are about 2048 sectors within this range, so as shown in FIG. 204g (-8001 in hexadecimal)
1) as the unit, omitting the upper digits, O~2047(1
Only the lower digits up to 7FFII in hexadecimal are attached as sector address SA.

In other words, the sector address SA increases from the actual sector address of 0 to the maximum sector address of 0.
.about.2047 are added repeatedly, and as a result, the sector address SA becomes 11 digits in binary.

The number of digits is approximately half of the 21 digits required in the past.

In this way, the sector address SA in this case is equal to the lower 11 digits of the actual sector address (real sector address RSA) on the optical disc 1, and the upper 10 digits of this real sector address R5A are the same as those of the microprocessor 22.
Therefore, the home position of the optical head 13 (standby position!!
It is determined by referring to the distance from

Note that the real address R5A is a serial number assigned to each sector of the optical disc 1 starting from 0, and is equal to the sector address SA conventionally assigned to the preformat area.

Next, an example of a positioning processing routine in the access processing of the optical disk I will be described with reference to the sector address SA.

As shown in FIG. 3, the macro processor 22 first calculates the amount of movement MV for moving the optical head 13 based on the target sector TS (actual sector address R8A) input from an external device and the current position of the optical head 13. (Process 101)
. That is, since the optical head 13 is always located at the home position, which is a predetermined standby position, before data access, the distance from the home position to the target sector TS is set as the movement amount MV.

After calculating the movement amount MV in this way, this is further converted into the number of movement pulses PM, which is output to the linear motor drive section 20 to operate the linear motor drive section 20, thereby causing the optical head 13 (Process 1)
．． 02).

After moving the optical head 13 in this way, input the sector address detected by the sector address detection unit 21, and change the sector where the optical head 13 is currently located to sector C3.
(processing 103).

Then, if the current sector C3 is equal to the target sector TS at this time (if the result of judgment 104 is YES), the positioning process is completed, so this process is ended and a positioning completion message is output to the external device.

If the current sector C8 is not equal to the target sector TS (if the result of decision 104 is No), the number of sectors from the current sector C8 corresponding to half the positioning error (in this case 10
The target sector TS is located within a range around 24).

Therefore, first, the value of (TS-C5) is compared with 1024 (determination 105). If the result of this judgment 105 is Y[ES, it means that the target sector TS is located in the previous set of the lower 11 digits where sector C3 is currently located (arrow in FIG. 2). TSI, C3I), (TS-C5
) from the value of 2048, which corresponds to the number of sectors of positioning error.
The number of moving sectors MS is corrected to the value obtained by subtracting the number of sectors MS (processing 106
).

If the result of judgment 105 is No, then (TS-C3)
is compared with -1024 (decision 107). If the result of this determination 107 is No, the target sector TS is
This is the case where the sector is located in the next set of the lower 11 digits where sector C8 is currently located (arrow TS2.C52 in Figure 2).
), the number of moving sectors MS is corrected to a value obtained by adding 2048 to the value of (TS-C5) (processing 108).

If the result of judgment 107 is YES, the target sector T
This is a case where S is located in the same group as the lower 11 digits where sector C3 is currently located (arrow TS3°C in Figure 2).
(see S3), in this case, the value of (TS-C5) is substituted into the number of moving sectors MS (process 109).

In this way, the position error due to coarse positioning control is calculated as the number of moving sectors MS.

Next, the absolute value of the number of moving sectors MS is compared with 1440, which corresponds to 60 tracks, and a judgment 110) is made. If the result of this judgment 110 is No, the position error is large, so the movement corresponding to the number of moving sectors MS is made. Process 111) to calculate the number of pulses PM, output this to the linear motor drive section 20 to move the linear motor 18 (process 112), and the count value of the moving pulse liver output from the pulse encoder 19 is the number of moving pulses PM. If they match and the result of determination 113 is YES, the linear motor 18 is stopped (process 114).

If the result of the judgment 110 is YES, the position error is small, so the number of moving tracks TM corresponding to the number of moving sectors MS is calculated (step 115), and the number of moving sectors MS is set in the variable N (counter). 116), until the value of this variable N becomes 0 (until the result of judgment 119 becomes YES), the track jump control unit 24 controls the optical head 13.
Track jump control is executed to jump one track (process 117), and the variable N is decremented (process 118).

As a result, the optical head 13 is positioned on the track where the target sector TS is located.

After executing these processes 114 and judgment 119, process 1
Return to step 03 and repeat the following process. Normally,
After judgment 119, the result of judgment 104 becomes YES, and this positioning processing routine ends.

Even when the sector address SA is recorded on the optical disc 1 with the upper digits omitted in this way.

The optical head 13 can be properly positioned.

In the above-mentioned embodiment, the case where the optical disc is driven by CAV was explained, but the optical disc is driven at a constant linear velocity (
The present invention can also be applied to the case of driving with ctV).

Further, various constants in the positioning processing routine may be appropriately set depending on the positioning accuracy of the optical disk drive device.

Furthermore, the format of the preformat area is not limited to that described above. For example, a sector synchronization number for identifying the sector synchronization signal may be placed next to the sector synchronization signal, or a frame synchronization signal may be further placed.

Note that the present invention is not limited to optical disk devices, but can be similarly applied to other high-density data recording devices.

[Effects] As explained above, according to the present invention, by omitting the upper digits of the sector address arranged in the preformat area, the preformat area can be reduced, thereby improving the recording efficiency of the optical disc. Get benefits.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an optical disk drive device according to an embodiment of the present invention, FIG. 2 is a signal arrangement diagram showing an example of sector address setting, and FIG. 3 is an example of a positioning processing routine. Figure 4 is a plan view showing an example of the structure of an optical disc, Figure 5 is a signal arrangement diagram showing an example of the recording format of an optical disc, and Figure 6 is a signal arrangement showing a conventional example of the preformat area. It is a diagram. 1... Optical disk, 12... Semiconductor laser, 13.
... Optical head, 14... Aperture lens, 15... Sensor section, 16... Actuator, 17... Servo circuit. DESCRIPTION OF SYMBOLS 18... Linear motor, 19... Pulse encoder, 20... Linear motor drive part, 21... Front and back address detection part, 22... Microprocessor, 23
. . . Interface circuit, 24 . . . Track jump control section.

Claims (1)

[Claims] A preformat area consisting of a preamble for matching circuit conditions, a sector synchronization signal for detecting the start of a sector, and a sector address signal for identifying a sector is placed before a data area consisting of multiple information frames. In a data recording method in which data is recorded on a recording medium in a sector configuration with an address set, the sector address signal forms only the lower digits of the target address in the preformat area, and is used when recording and reproducing data on the recording medium. First, the recording/reproducing means performs coarse positioning control of the target address, and then in the fine positioning control after the coarse positioning control, the difference between the target sector address and the sector address reached by the coarse positioning control corresponds to the positioning accuracy. A data recording method characterized in that when the number of sector addresses is larger than 1/2 of the number of sector addresses, the difference is corrected by adding or subtracting the number of sector addresses corresponding to the positioning accuracy.