Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
2000-03-28
2003-09-16
Psitos, Aristotelis M (Department: 2653)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S047540
Reexamination Certificate
active
06621783
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to methods of retrieving disk information from an optical disk, such as a CD-R or CD-RW disk (which will hereinafter be generically called a “CD-R/RW” disk), and controlling access and recording to a CD-R/RW disk, and optical disk recording apparatus for recording desired information onto a CD-R/RW disk. More particularly, the present invention is concerned with a technique which allows disk information to be obtained quickly and accurately from a multi-session-recorded CD-R/RW disk using PMA (Program Memory Area) information recorded in a PMA area of the optical disk and which permits access to each desired track and additional writing (including overwriting) of a track on the basis of the thus-retrieved disk information. Note that the terms “disk information” used in the context of the present invention refers to such information recorded in the PMA and TOC (Table Of Contents) areas of the CD-R/RW disk.
Multi-session recording is standardized as an example of various recording schemes applicable to the CD-R/RW disks. The multi-session recording scheme is characterized by recording a plurality of sessions on a CD-R/RW disk, each of which is a set of a lead-in area, a program area and a lead-out area. More specifically, in each of the sessions, the lead-in area has stored therein lead-in information such as TOC information of the individual tracks present in that session. In many cases, the program area in the session has stored therein information including user data and a path table continuing from a preceding session. Further, according to the multi-session recording scheme, the sessions are recorded on the disk one after another from the disk's inner circumference to the outer.
Therefore, the conventional CD-R drive, CD-RW drive or drive having a combination of the functions of the CD-R and CD-RW drives (hereinafter “CD-R/CD-RW drive”) are designed in such a way that upon insertion or loading of a disk into the drive, Q subcode information in the innermost lead-in area is read out in order to retrieve all the disk information and latest user data (path table recorded in the last session) and then, once the disk in question has been identified as a multi-session-recorded disk, a “disk search” is conducted to search for all the disk information up to the last session and the path table recorded in the last session.
Among various approaches for searching for all the disk information up to the last session is to sequentially read the lead-in areas of the individual sessions. Namely, according to this approach, the TOC information of the first or leading session is read out along with program-starting-time information of the second session, then access is made, on the basis of the program-area-starting-time information of the second session, to the lead-in area of the second session to read out the TOC information of the second session along with program-starting-time information of the third session, then access is made, on the basis of the program-area-starting-time information of the third session, to the lead-in area of the third session to read out the TOC information of the third session along with program-starting-time information of the fourth session, and so on. Such procedures are repeated to sequentially access the lead-in areas of the individual sessions of the disk. When it is determined that there is no more data recorded in the lead-in area of a specific session accessed, the specific session is considered to be an unrecorded portion and the session immediately preceding the specific session is judged to be the last session. Once all the disk information up to the last session has been retrieved, access is made to the path table and the like recorded in the last session on the basis of the disk information of the last session, to thereby retrieve the path table and the like from the last session. Only after completion of the retrieval of these information, access to the individual tracks and additional writing of a new track become possible.
Further, the conventionally-known techniques for erasing an entire recorded surface of the CD-RW disk have two major types, the “full erase” and “quick erase”. The “full erase” technique is characterized by writing logical “0”s onto the entire recorded surface and has the advantage of being able to completely erase all the recorded contents; however, this technique is disadvantageous in that it takes a long erasing time. For example, where the records are to be erased from a 74-minute disk at the standard (non-increased or non-reduced) speed, the full erase would take at least 74 minutes or more. The “quick erase” technique, on the other hand, is characterized by erasing information recorded in the PMA area existing inward of the lead-in area of the first session as well as information recorded from the lead-in area of the first session to a pre-gap in such a way that information recorded outward of the pre-gap is left unerased; note that the PMA area is an area for storing the PMA information pertaining to the currently-recorded track, such as starting and ending times etc. of the track, each time a succession of recording procedures is suspended. Also note that the PMA area also keeps storing the disk information of each already-completed session until the full erase or quick erase is instructed. Once the recorded information is erased from the PMA area and lead-in area of the first session, a multi-session-capable optical disk apparatus, having installed therein the CD-RW disk, is no longer able to obtain any information from either the initially accessed PMA area or the lead-in area of the first session, so that the optical disk apparatus determines that all the tracks have been erased. As a consequence, the quick erase technique can achieve the same advantage as the full erase technique by erasing operations of a shorter time.
However, with the above-mentioned approach of sequentially reading the lead-in areas of the individual sessions, a very long time would be taken to retrieve the information of all the tracks if the disk has a great many sessions, which would undesirably result in a long waiting time before reproduction or additional writing of a track is permitted.
Further, because the quick-erased CD-RW disk still has data on and after the first track of the first session left unerased, the following inconveniences tend to be encountered in newly performing multi-session recording. Namely, upon loading of a CD-RW disk having data recorded thereon up to the first session after the quick erasure, the multi-session-capable optical disk apparatus retrieves program-area-starting-time information of the second session from the lead-in area of a new first session and, on the basis of the starting-time information, accesses particular addresses where the lead-in area of the second session is supposed to exist. If certain data of any of the old sessions, which existed before the quick erasure, is still left at the accessed addresses, then the optical disk apparatus sometimes erroneously retrieves the left data. Particularly, if the left data is data of the lead-in areas of some old session, the optical disk apparatus would take it to be data of the lead-in area of the second session, on the basis of which it sequentially reads the data of the lead-in areas of the old sessions. By so doing, the optical disk apparatus would retrieve all the TOC information of the old sessions and also obtain the path table of the last one of the old sessions on the basis of the TOC information of the last session. Thus, although the new first session has now been recorded on the optical disk, no access can be made to individual files of the new first session due to the fact that the path table obtained includes no information corresponding to the new first session. Another inconvenience is that a new second session can not be recorded on the disk immediately after the new first session.
Furthermore, because no erasure takes place in the CD-R disk, arrangements have to
Pillsbury & Winthrop LLP
Psitos Aristotelis M
Yamaha Corporation
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