JP2002008244A - Method for erasing recorded data of disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of such a problem that the excessive time is required for erasing all data recorded on a disk due to the necessity to trace tracks by laser beams emitted from an optical head for erasing real data recorded on the disk. SOLUTION: When all of the data recorded on the disk are erased, the balance adjustment of the tracking servo in the optical disk is controlled so as to be shifted from the proper track position, or the balance adjustment of the focus servo is controlled so as to be shifted from the proper focussing position, then the laser beams from the optical head is allowed to emit so as to spread over the adjacent two tracks or three tracks, and also the output level of the laser beams of the optical head is set so that the recorded data on the two tracks or three tracks are erased. Thus, the recorded data on the two tracks or three tracks are simultaneously erased, and the reduction of the time required for erasing all of the real data recorded on the disk is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for erasing recorded data in a disk device for recording data on a disk by using a laser beam emitted from an optical head, and more particularly to a method for erasing data by narrowing a track interval. The present invention relates to a method for erasing recorded data in a disk device suitable for erasing a disk.

[0002]

2. Description of the Related Art As a disk device for optically reading and writing signals using an optical head, a CD is used.
(Compact disk) In addition to compatible products, a DV with the same disk diameter as the CD to ensure mechanical compatibility and record at a higher density than the CD to increase the capacity
There are products compatible with D (Digital Versatile Disc).

In a disk drive, an optical head and a magnetic head are arranged to face each other with a magneto-optical disk interposed therebetween, and the magneto-optical disk is irradiated with laser light emitted from the optical head and generated by the magnetic head. There is a magneto-optical recording type disk device that performs data recording by applying a magnetic field.

In such a magneto-optical recording disk device, a laser pulse magnetic field modulation recording system is employed, and a magnetic super-resolution reproducing system is employed to increase the recording density.

[0005] In the above-mentioned disk device in which the recording density is increased, land / groove recording for recording data on both groove-shaped groove tracks of the disk and land tracks between the groove tracks is adopted. In a disk drive, if the track spacing is reduced due to the high density, cross writing on adjacent tracks becomes a problem. Therefore, when recording data on a disk, set the laser beam generated from the optical head to the optimum recording output at the time of initialization, and change the optimum recording output according to environmental changes such as temperature changes. The cross light is prevented as much as possible.

[0006]

When erasing data recorded on a disk in a disk device, the data itself is erased instead of erasing the data itself, but by erasing only the entry information corresponding to the data to be erased. A method for performing erasure is known. With this method, only the entry information needs to be erased, so that the erasure can be performed in a short time.

However, in the case of erasing only the entry information, the erased data cannot be read out in normal use, but since the actual data remains on the disk, the erased data can be read out by using some means. Therefore, there is a problem of leakage or falsification of data contents.

Therefore, it is necessary to erase the actual data. However, in order to erase the actual data, it is necessary to trace a track on which the actual data to be erased is recorded by a laser beam emitted from the optical head. In this case, it takes too much time to erase all data recorded on the disc.

[0009]

According to the first aspect of the present invention,
When erasing all data recorded on the disk, the balance adjustment of the tracking servo in the optical head is controlled so that the laser beam from the optical head is shifted from the proper track position at which the track on the disk is correctly irradiated. The laser beam is irradiated over two adjacent tracks, and the level of the laser light output of the optical head is set so that the recorded data recorded on the two tracks is erased. At the same time.

According to a second aspect of the present invention, when erasing all data recorded on the disk, the balance of the focus servo in the optical head is adjusted by the laser light from the optical head correctly on the signal recording surface of the disk. The laser beam from the optical head is controlled so as to deviate from the proper focus position to enlarge the light spot diameter on the signal recording surface of the disk with the laser light from the optical head, The laser beam output level of the optical head is set so that the recording data recorded on the adjacent track is erased, and the recording data on the adjacent track is erased simultaneously with the irradiation track.

[0011]

FIG. 1 is a circuit block diagram showing an embodiment of an optical disk recording apparatus for explaining a recording data erasing method of a disk apparatus according to the present invention.

The disk device shown in FIG. 1 employs land / groove recording, and land tracks and groove tracks are spirally formed on a disk d, respectively.

Reference numeral 1 denotes an interface for controlling data exchange with a host device 3 such as a personal computer or the like, which is externally connected via a connection terminal 2. Reference numeral 4 denotes data to be recorded on the disk d. This is an encoder that modulates recording data having a structure.

Reference numeral 5 denotes an optical head which emits a laser beam for tracing the disk d and writes and reads recording data on the disk d. Reference numeral 6 denotes an optical head generated from the optical head 5 based on the recording data output from the encoder 4. The laser modulation circuit 7 modulates the output intensity of the laser light to be generated and generates a write pulse corresponding to the recording data. The RF modulation circuit 7 amplifies the RF signal of the received light output obtained by the optical head 5 and binarizes the RF signal. An amplifier 8 feeds back various light-receiving outputs obtained by the optical head 5 to control various servos related to the optical head 5, that is, a head servo circuit that controls a tracking servo, a focus servo, and a thread servo. 9 denotes a tracking servo system and a focus servo. Generates an offset signal to be applied independently to each system An offset signal generator that.

The tracking servo system and the focus servo system of the head servo circuit 8 are constructed as shown in FIG. 2, and the tracking servo system comprises a trace position traced by a laser beam generated from the optical head 5 and a disk d. A tracking error signal generation circuit (TE signal generation circuit) 10 for calculating a tracking error signal indicating the amount of deviation from the track from a predetermined light receiving output of the optical head 5, and a tracking error signal generated by the TE signal generation circuit 10 And a tracking control circuit 11 that drives a tracking actuator of the optical head 5 to perform tracking control so that a tracking error signal for offset correction obtained by adding an offset signal generated from the offset signal generation circuit 9 to “0”. ing.

On the other hand, the focus servo system of the head servo circuit 8 sends a focus error signal indicating the amount of deviation between the focal point of the laser beam generated from the optical head 5 and the signal recording surface of the disk d to a predetermined value of the optical head 5. A focus error signal generation circuit (FE signal generation circuit) 12 for calculating from a light receiving output; and an offset correction circuit for adding an offset signal generated from an offset signal generation circuit 9 to the focus error signal generated by the FE signal generation circuit 12. The optical head 5 sets the focus error signal to "0".
And a focus control circuit 13 that drives the focus actuator to perform focus control.

A disk motor 14 rotationally drives the disk, and 15 is a motor servo circuit for controlling the drive of the disk motor 14. The motor servo circuit 15 controls the rotation of the disk by using a wobble component extracted from each track of the land and groove of the disk when recording the disk.

Reference numeral 16 denotes a system control circuit for performing system control relating to disk recording. The system control circuit 16
Are offset output setting means 17 for setting the output level of the offset signal generated from the offset signal generating circuit 9 and laser output setting means for appropriately setting the output of the laser light generated from the optical head 5 according to each operation mode. 18 and an erasure setting means 19 for setting how to erase the recorded data recorded on the disk.

The laser output setting means 18 sets the output level of the laser beam generated from the optical head 5 to an optimum recording level at the time of initialization when data is recorded on the disk d, and corresponds to a temperature change. Control is performed to change the output level of the laser beam so that it always becomes the optimum recording level.

In the disk device configured as described above, when erasing all the real data recorded on the disk d, the host device 3 performs an operation of erasing all the real data. When the operation is set to the operation mode for erasing all the actual data by the erasure setting means 19 by this operation, the offset output setting means 17 outputs the offset of the tracking servo system generated from the offset signal generation circuit 9 applied to the tracking control circuit 11. The signal output level is controlled so as to shift the balance adjustment of the tracking servo, and the laser light from the optical head 5 is irradiated between the tracks from the proper track position where the laser light is appropriately applied to the tracks on the disk d. The offset signal of the tracking servo system so that As a result, the laser beam from the optical head 5 traces substantially the center of the land and groove tracks, and irradiates over two adjacent tracks on the disk d.

On the other hand, the laser output setting means 18 sets the laser light output level of the optical head 5 so as to simultaneously erase the recorded data recorded on two adjacent tracks.

That is, in the operation mode state in which the actual data is completely erased, the laser beam emitted from the optical head 5 is irradiated over two adjacent tracks, and the recording data of the two tracks is erased simultaneously. Become.

Accordingly, the recording data of two adjacent tracks are simultaneously erased, and the entire erasure of the actual data on the disk d is performed in half the time when one track is traced.

Next, as an erasing method for erasing all the actual data recorded on the disk d, another erasing method different from the erasing method described above will be described below.

When an operation for erasing all the actual data recorded on the disk d is performed by the host device 3, the operation is set to an operation mode for erasing all the actual data by the erasure setting means 19 by this operation. Reference numeral 17 controls the output level of the offset signal of the focus servo system generated from the offset signal generation circuit 9 applied to the focus control circuit 13 so as to shift the balance adjustment of the focus servo. The laser servo beam is defocused from the proper focus position where the signal is properly focused on the signal recording surface, and the offset signal of the focus servo system is applied so that the light spot diameter on the signal recording surface extends to both adjacent tracks on both sides of the irradiation track. Set. As a result, the laser beam from the optical head 5 irradiates both the adjacent tracks at the same time as the irradiation track.

On the other hand, the laser output setting means 18 sets the laser light output level of the optical head 5 in order to compensate for a decrease in the irradiation intensity on the signal recording surface due to the defocus of the laser light.

Therefore, when the output level of the laser beam is set to an appropriate level for the entire erasing mode of the actual data, the optical head 5
Cross-writing is performed on the track adjacent to the irradiation track irradiated by the laser light emitted from the laser beam, and the recording data on the adjacent tracks on both sides are erased simultaneously with the irradiation track.

When the erasure setting means 11 is set to the operation mode for erasing all the actual data, the track to be traced by the laser beam from the optical head 5 is set to one of the land and the groove.

Therefore, one of the lands and grooves is traced without switching the track to be traced, and the actual data on the disk d is erased. At the time of this tracing, the recording data on the adjacent track is erased simultaneously with the irradiation track. Therefore, the entire erasure of the actual data on the disk d is performed in half the time when tracing both the land and groove tracks.

In this case, since adjacent tracks adjacent to the irradiation track directly traced by the laser light from the optical head 5 are erased by cross writing, adjacent tracks that are not directly traced by the laser light from the optical head 5 are traced. Cross-writing is performed twice before and after the track to be erased, and the erasure of the adjacent track is ensured even with the peripheral light of the laser beam for erasing the adjacent track.

When an operation for erasing a part of the actual data is performed by the host device 3, the operation is set to a partial erasure mode for partially erasing the actual data by the erasure setting means 19, and the laser output is set. The output of the laser light generated from the optical head 5 is set by the setting means 18 to a level at which cross writing to an adjacent track is not performed, and only the actual data at the designated address is erased.

The disk device shown in FIG. 1 is an optical disk recording device that performs disk recording by optical modulation. However, the present invention is not limited to this, and the present invention applies a laser beam emitted from an optical head to a magneto-optical disk. In addition, the present invention can also be applied to a magneto-optical disk recording device that performs data recording by applying a magnetic field generated by a magnetic head. In addition to generating a recording magnetic field from the magnetic head in accordance with the modulated recording data, the optical head simultaneously generates a pulsed laser beam to perform recording on the disk. The laser light output should be set to a level that erases the recorded data recorded on the adjacent track. .

[0033]

As described above, according to the present invention, when erasing all the actual data recorded on the disk, one or two tracks are traced by the laser beam generated from the optical head. And the time for erasing all the actual data can be shortened.

In this case, two or three tracks are simultaneously traced by shifting the balance adjustment of one or both of the tracking servo and the focus servo, so that the laser beam generated from the optical head can be traced simultaneously. Alternatively, the recording data recorded on three tracks can be erased simultaneously.

In particular, when the balance adjustment of the focus servo is shifted, by setting the track to be traced by the laser beam generated from the optical head to one of the land and the groove, it is easy to control the optical head to trace the track. At the same time, an adjacent track that is not directly traced is cross-written twice before and after the track to be traced, so that the erasure of the adjacent track is ensured even with the peripheral light of the laser beam for erasing the adjacent track. Can be done.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing one embodiment of an optical disk recording apparatus for explaining a recording data erasing method of a disk apparatus according to the present invention.

FIG. 2 is a circuit block diagram showing a tracking servo system and a focus servo system of a head servo circuit 8.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Interface 4 Encoder 5 Optical head 6 Laser modulation circuit 9 Offset signal generation circuit 16 System control circuit 17 Offset output setting means 18 Laser output setting means 19 Erase setting means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D090 AA01 BB03 CC03 DD03 EE07 FF02 FF05 KK03 5D118 AA03 BA01 BB05 BF04 CA09 CD02 CD11

Claims (2)

[Claims] 1. A recording data erasing method for a disk device for recording data on a disk by irradiating a laser beam generated from an optical head with tracking servo to follow a track of the disk, and recording the data on the disk. When erasing all data, the balance of the tracking servo in the optical head is controlled so that the laser light from the optical head is shifted from the proper track position where the laser light from the optical head is correctly irradiated on the track of the disk, and the laser light from the optical head is adjacent Irradiation is performed over two tracks, the level of the laser beam output of the optical head is set so that the recorded data recorded on the two tracks is erased, and the recorded data on the two adjacent tracks is simultaneously erased. A method for erasing recorded data in a disk device, characterized in that: 2. A method for erasing recorded data in a disk device for recording data on a disk by irradiating a laser beam generated from an optical head on a signal recording surface of the disk by focusing with a focus servo and irradiating the disk with the laser light. When erasing all recorded data, the balance of the focus servo in the optical head is controlled so that the laser beam from the optical head is shifted from the proper focus position where the laser beam from the optical head is correctly focused on the signal recording surface of the disk. In order to erase the recording data recorded on the adjacent track adjacent to the irradiation track of the disk irradiated with the laser light from the optical head while enlarging the light spot diameter on the signal recording surface of the disk with the laser light from Set the laser light output level of the optical head, and record A method for erasing recorded data in a disk device, wherein data is erased.