JP2000215532A - Erasing method for cd-rw disk and cd-rw disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable prevention of erroneous reading of data before quick erasing by erasing a program memory area(PMA) and a read-in region of all sessions leaving program area and read-out area of all sessions. SOLUTION: A control section 24 records an erasing signal in a PAM region with the prescribed format based on a start time of the PAM region stored in a memory 26 and the last time of a recording part in the PAM area. Next, in a read-in region of a first session, a frame from a start position up to the last time position is erased, based on information of the start time of the first session stored in the memory 26. After a second session, an erasing signal is recorded with the prescribed erasing format based on start time information of a program region of each session stored in the memory 26 and erasing is performed. Since the PAM region and a read-in region of each session are erased, information of a program region cannot be read in.

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 a multi-session recorded CD-RW (Compact Disk-Rewritable) disk and a CD-RW disk device, and to erasing the disk in a shorter time than erasing (full erase) the entire disk. This prevents the information that should have been deleted from being read by mistake.

[0002]

2. Description of the Related Art Multi-session recording is standardized as one of recording methods for CD-RW discs. This is because a combination of the lead-in area, the program area, and the lead-out area is regarded as one session, and a plurality of sessions are defined as one session.
This is recorded on a single disk. In each session, the lead-in area includes a TOC (Table of Contents) which is information of a track in each session.
contents). The program area often stores information including user data and a path table from a previous session. In addition, recording is performed in such a manner that sessions are sequentially recorded from the inner circumference to the outer circumference of the disc.

Therefore, multi-session compatible optical disk devices (CD-ROM drive, CD-R drive,
CD-RW drive), in order to obtain all the track information and the latest user data information, that is, the path table recorded in the last session, the Q of the innermost lead-in area after the disc is loaded.
When the subcode information is read to determine that the disc is a multisession-recorded disc, a disc search is performed to find all track information up to the last session and a path table of the last session.

As a method of searching for all track information up to the last session, there is a method of successively reading the lead-in area of each session. That is, first, the TOC information of the lead-in area of the first session is read, and the program start time information of the second session obtained at this time is used as a clue to access the lead-in area of the second session. The TOC information of the third session is read, and the TOC information of the third session is read by accessing the lead-in area of the third session next using the program start time information of the third session obtained at this time as a clue. The session sequentially accesses the lead-in area of each session. Then, if there is no data in the lead-in area at the accessed location, it is determined as an unrecorded portion, and the session immediately before that is determined as the last session. When all the track information up to the last session is obtained, access to the path table and the like of the last session is continuously performed based on the track information of the last session to obtain the path table and the like of the last session.

A conventional erasing method for erasing the entire surface of a CD-RW disk is a full erase (Full E).
race and Quick Erase (Quick Eras)
e). Full erasure writes logic "0" over the entire surface, and has the advantage of completely erasing the recorded contents, but has the disadvantage of requiring a long erasing time. For example, when erasing a 74 minute disc at 1 × speed, 74
It will take more than a minute. On the other hand, quick erase is a PM that is on the inner peripheral side of the lead-in area of the first session.
A (Program Memory Area: area in which information of each track of the session before one session is completed) and only the lead-in area of the first session to the pre-gap are erased. When the PMA area and the lead-in area of the first session are erased, the multi-session compatible optical disc apparatus loaded with the CD-RW disc does not receive any information on tracks from the PMA area to be accessed first or from the lead-in area. Since it cannot be obtained, it is determined that the disk has all tracks erased. Therefore, the quick erase can achieve the same effect as the full erase by a short erasing operation.

[0006]

Since the data other than the PMA area and the lead-in area of the first session remains on the CD-RW disc on which quick erasing has been performed, a problem occurs when a new multi-session recording is performed. May be. In other words, quick erase,
When a CD-RW disc newly recorded up to the first session is loaded into a multi-session compatible optical disc device,
The optical disk device acquires the start time information of the program area of the second session from the lead-in area of the new first session, and accesses the address where the lead-in area of the second session should exist based on this information. At this time, if the lead-in area of the old data before the quick erase was accidentally present at that address, the optical disk device erroneously judges that the lead-in area of the second session was there, All the TOCs of the remaining old sessions
While acquiring information, the path table of the old last session is obtained based on the TOC information of the old last session. As a result, even though the new first session is recorded on the optical disc, there is no information corresponding to the new first session in the acquired path table. Inaccessible. Further, even if an attempt is made to record a new second session, the recording cannot be continued immediately after the new first session.

The present invention solves the above-mentioned problems of the conventional quick erase, and provides a method for erasing a CD-RW disc and a CD-RW disc apparatus which prevent erroneous reading of data before quick erase. It is assumed that.

[0008]

A method for erasing a CD-RW disc according to the present invention is a multi-session recorded CD.
A method for erasing a RW disc, wherein a PMA is stored while leaving a program area and a lead-out area for all sessions;
The area and the lead-in area of all sessions are erased.

Further, the method for erasing a CD-RW disc according to the present invention is characterized in that the multi-session recorded CD-RW disc is recorded in a Q subcode in a lead-in area of a first session at an appropriate time. The start time information of the program area of the second session being read is read, and the second time immediately before the program area is read based on the information.
Access the lead-in area of the session, read the start time information of the program area of the third session recorded in the Q subcode of the lead-in area of the second session, and immediately before the program area based on the information, By accessing the lead-in area of a certain third session and repeating this operation, the start time information of the program area of all sessions or the recording position information of the lead-in area based on the information is acquired and stored. RW
When a disc erasing command is given, the PMA area is erased, and based on the stored start time information of the program area of all the sessions or the recording position information of the lead-in area, the PMA area is sequentially stored in the lead-in area of all the sessions. Access is made to erase the area.

According to the CD-RW disc apparatus of the present invention, when a multi-session recorded CD-RW disc erasure command is given, the PMA area and all session areas are left, except for the program area and lead-out area of all sessions. Is provided with a control unit for performing control to erase the lead-in area.

In the CD-RW disc apparatus of the present invention, at an appropriate time after the multi-session recorded CD-RW disc is loaded, the CD-RW disc is recorded in the Q subcode of the lead-in area of the first session. The start time information of the program area of the second session is read, and the lead-in area of the second session immediately before the program area is accessed based on the information. The start time information of the recorded program area of the third session is read, and the third time immediately before the program area is read based on the information.
By accessing the lead-in area of the session and repeating this operation, the start time information of the program area of all sessions or the recording position information of the lead-in area based on the information is acquired and stored in the memory.
When a command to erase the W disk is given, the PMA area is erased, and based on the stored start time information of the program area of all sessions or the recording position information of the lead-in area, the PMA area is written to the lead-in area of all sessions. It is provided with a control unit for performing control for sequentially accessing and erasing the area.

According to the present invention, since the PMA area and the lead-in area of all sessions are erased, the information before erasure is prevented from being erroneously read, and the program area and the lead-out area do not need to be erased. , Can be erased in a short time.

[0013]

Embodiments of the present invention will be described below. FIG. 1 shows a schematic configuration of a CD-RW drive 10 to which the present invention is applied. The CD-RW disc 12 is rotated by a spindle motor 14 and recording is performed by an optical head 16. The rotation control of the spindle motor 14, the feed control of the optical head 16, the focus control, the tracking control, and the like are performed by the servo circuit 18 based on the return light detection signal of the optical head 16. The recording / erasing signal generation circuit 20 generates a recording signal (laser driving signal) based on the recording information sent from the host computer 22 at the time of recording, drives a laser light source in the optical head 16 to drive a CD-ROM.
The information is recorded on the RW disc 12. At the time of erasing, an erasing signal of a predetermined format is generated, and the laser light source is driven to record (ie, erase) the erasing signal on the CD-RW disc 12. The control unit 24 controls the host computer 22 based on command inputs such as recording, reproduction, and erasure.
Based on the command from the control unit, each unit in the CD-RW drive 10 is controlled to execute a corresponding operation. Memory 26
Stores information read from the PMA area of the CD-RW disc 12, the lead-in area of each session, and the like.

The information is taken into the memory 26 by a CD-R.
When the W drive 10 detects the loading of a disk, the operation is automatically performed based on a command from the control unit 24. That is,
When the CD-RW disc 12 is loaded into the CD-RW drive 10, the control unit 24 positions the optical head 16 at the start position (fixed position) of the PMA area, and records information (recording) recorded in the PMA area. The TOC information of the session in the middle is taken into the memory 26. Next, the optical head 16 is positioned at the start position (fixed position) of the lead-in area of the first session, and the information of the lead-in area is taken into the memory 26. At this time, the memory 26
When the "POINT" data indicates B0 when the "ADR" data of the Q subcode of the information fetched in the mode is mode 5, the control unit 24 determines that the disc is a multi-session disc, and the Q subcode at that time is determined. "PMIN, P
SEC, PFRAME "is determined as the start time information of the program area of the next session (second session).

As soon as the information of the lead-in area of the first session has been fetched into the memory 26, the start position of the lead-in area of the second session (CD-R
In the W standard, the position is defined as a position that is 01 minutes 00 seconds 00 frames before the start time of the program area. ), And similarly, the memory 26 of the information of the lead-in area is accessed.
Import to. Thereafter, similarly, the start position of the lead-in area of the next session is sequentially accessed based on the start time information of the next session read from the lead-in area of each session, and the information recorded in the lead-in area of each session is sequentially accessed. Is taken into the memory 26. If the information indicating the lead-in area is not read from the position accessed as the start position of the lead-in area in the next session, it is determined that the area is an unrecorded area or an erased area, and the initial operation when the disc is loaded ends. .

As a result of this initial operation, P
Data read from the MA area and the lead-in area of each session (the last session number recorded so far, the start time of the program area of each session, the start time of the first session, the start time of the PMA area, the PMA area (Including information such as the last time of the recorded section of the recorded section). When the initial operation is completed, the CD-RW drive 10 enters a standby state in which commands such as recording, reproduction, and erasing are received, and executes a corresponding operation in response to a command from the host computer 22 based on an external command input.

The erasure control by the control unit 24 when erasure of the entire CD-RW disc 12 is instructed will be described with reference to the flowchart of FIG. When an instruction to erase all tracks by quick erase is given to the host computer 22 from the outside, the host computer 22 sends the CD-RW
A command to erase all tracks by quick erase is issued to the drive 10. In response to this, the control unit 24 sets P P based on information on the start time of the PMA area stored in the memory 26 and the last time of the recorded part in the PMA area.
From the start position of the MA area to at least the end position of the recorded part in the PMA area, an erase signal is recorded in a predetermined erase format of the PMA area, and information recorded in the PMA area is erased (S1). .

Next, the lead-in area of all sessions is erased (S2 to S5). As an example, a case where erasing is performed in order from the first session (first session) will be described. The lead-in area of the first session is the start time of the first session (=
Based on the information of the first session's lead-in area (start time), the part from the start position to the 99:59:74 frame defined as the last time of the first session's lead-in area is erased. Memory 2 after the second session
6 based on the start time information of the program area of each session stored in the session 6 from the start position of the lead-in area to the start position of the program area, which is defined as 1 minute 00 second 00 frame before that time. Erasing is performed by recording an erasing signal in a predetermined erasing format in the lead-in area or a predetermined erasing format in the program area.

When the erasure of the lead-in area of all sessions is completed, the information (maximum session number,
It includes information such as the start time of the program area of each session, the start time of the first session, the start time of the PMA area, and the last time of the recorded part in the PMA area. ) Is set to a blank disk (unrecorded disk) state (S
6). Thus, the erase operation is completed.

FIG. 3 shows a state before and after erasing by the above erasing operation. The portions indicated by hatching are portions where valid information is recorded. The PMA area and the lead-in area of each session have been erased by the erase operation. Although the information is still recorded in the program area, since the PMA area and the lead-in area of each session have been erased, there is no clue to read the information in the program area. Cannot be read.

In the above-described embodiment, the start time information of the program area of each session is stored in the memory 26, and when the erasure is instructed, the position 1 minute 00 second 00 frame before that is read. The erasing is started from the start position of the program area, and the position before 1 minute 00 second 00 frame before that is determined based on the start time information of the program area of each session and stored in the memory 26. In addition, when an erasure is instructed, erasing can be performed by directly accessing the stored position indicated by the start time information of the lead-in area of each session.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a CD-RW drive according to an embodiment of the present invention.

FIG. 2 is a flowchart showing erasure control by a control unit 24 of FIG. 1;

3 is a schematic diagram showing a recording state before erasure and a recording state after erasure of a CD-RW disc by the erasure control of FIG. 2;

[Explanation of symbols]

10 CD-RW drive (CD-RW disk device), 12 CD-RW disk, 24 control unit, 26
memory.

Claims (4)

[Claims] 1. A method for erasing a multi-session recorded CD-RW disc, the method comprising erasing a PMA area and a lead-in area of all sessions while leaving a program area and a lead-out area of all sessions.
How to erase a disk. 2. At an appropriate time after a multi-session recorded CD-RW disc is loaded, the second session recorded in the Q subcode of the lead-in area of the first session.
The start time information of the program area of the session is read, and the second time immediately before the program area is read based on the information.
Access the lead-in area of the session, read the start time information of the program area of the third session recorded in the Q subcode of the lead-in area of the second session, and immediately before the program area based on the information, By accessing the lead-in area of a certain third session and repeating this operation, the start time information of the program area of all sessions or the recording position information of the lead-in area based on the information is acquired and stored. When a command to erase the RW disk is given, the PMA area is erased, and based on the stored start time information of the program area of all the sessions or the recording position information of the lead-in area, the PMA area is written to the lead-in area of all the sessions. CD-R for sequentially accessing and erasing the area
How to erase W disk. 3. When a multi-session recorded CD-RW disc erasure command is given, a PM and a lead-out area of all sessions are left.
A CD-RW disk device comprising a control unit for performing control to erase the A area and the lead-in area of all sessions. 4. At an appropriate time after loading a multi-session recorded CD-RW disc, the second session recorded in the Q subcode of the lead-in area of the first session.
The start time information of the program area of the session is read, and the second time immediately before the program area is read based on the information.
Access the lead-in area of the session, read the start time information of the program area of the third session recorded in the Q subcode of the lead-in area of the second session, and immediately before the program area based on the information, By accessing the lead-in area of a certain third session and repeating this operation, the start time information of the program area of all sessions or the recording position information of the lead-in area based on the information is acquired and stored in the memory. C
When a command to erase the D-RW disc is given, PM
A control is performed to erase the A area and sequentially access the lead-in area of all sessions based on the stored start time information of the program area of all sessions or the recording position information of the lead-in area to erase the area. A CD-RW disc device having a control unit.