Dynamic information storage or retrieval – Control of storage or retrieval operation by a control... – Control of information signal processing channel
Reexamination Certificate
1999-09-27
2003-03-25
Hindi, Nabil (Department: 2753)
Dynamic information storage or retrieval
Control of storage or retrieval operation by a control...
Control of information signal processing channel
C369S047270, C369S275300
Reexamination Certificate
active
06538964
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an optical recording method and apparatus and, more particularly, to an optical recording method and apparatus using a rewritable optical recording medium which has previously recorded address information.
2. Description of the Related Art
Recently, a digital versatile disc-rewritable (DVD-RW) has attracted considerable attention as one of rewritable optical recording media.
A blank or brand new DVD-RW has previously recorded address guide information which is referred to as LPP address. The LPP address is provided by forming land pre-pits on a recording surface of the DVD-RW. A recording operation is performed by forming recording pits on the recording surface of the DVD-RW by referring to the LPP address. A group of recording pits form a sector which represents 2-kilobyte user data. An address (sector address) is assigned to each sector. Normally, the LPP address matches the sector address.
A minimum unit of data recorded on the DVD-RW is referred to as a block which normally includes 16 sectors. It is possible to record information (recording pits) over a plurality of blocks by a single continuous recording operation. However, when a recording operation for adding information to previously recorded information or an overwriting (rewriting) operation is performed on the DVD-RW, a link is generated between a previously recorded block and a newly recorded block. According to the nature of the link, user data cannot be recorded in the link part. There are various sizes (lengths) for the link such as a 0-kilobyte link, a 2-kilobyte link or a 32-kilobyte link.
According to the 0-kilobyte link, there is no unusable area in the link part. However, a drive margin in the link part is small, and a high accuracy is required for setting a start position of a recording operation. Additionally, a service life of the disc may be shortened since a start position of recording cannot be shifted and recording is performed many times in the same link part.
According to the 32-kilobyte link, a recordable area corresponding to 32 kilobytes (16 sectors) is assigned to the link part. When the 32-kilobyte link is used, reliability of the user data is high. However, since a large recordable area is assigned to the link part, an amount of information recordable on a single DVD-RW is extremely reduced.
According to the 2-kilobyte link, a recordable area corresponding to 2 kilobytes (one sector) is assigned to the link part. The 2-kilobyte link has an advantage in that a sufficient margin is provided by the link part while an amount of information recordable on a single DVD-RW is not greatly reduced as is in the case of the 32-kilobyte link.
As a method for achieving the 2-kilobyte link, there are an internal link method and an external link method. According to the internal link method, the link part is included in a block. Accordingly, if the block contains 32 kilobytes, user data included in a single block is 30 kilobytes. (16×2 kilobytes−2 kilobytes=30 kilobytes) On the other hand, according to the external link method, the link part is provided outside the block. Thus, the user data in a single block remains unchanged, that is, the user data included in a single block is 32 kilobytes.
Generally a computer treats data by a power of two. A filing system using a conventional optical information recording medium is also based on such a data structure. In the internal link method, user data becomes a multiple of 30 kilobytes which is not a power of two. Thus, there is a problem that the internal link method is inconvenient for a conventional filing system. On the other hand, since the user data treated by the external link method is 32 kilobytes, the external link method is easily applicable to a conventional filing system.
When data is recorded by the external link method using 2-kilobyte link (hereinafter, referred to as 2-kilobyte external link method), the link part corresponding to a single sector (2 kilobytes) is provided between adjacent blocks. Accordingly, a sector address which is recorded with the use data shifts from the previously recorded LPP address. As mentioned above, a unit of data recorded on the DVD-RW corresponds to a block which contains 16 sectors. Thus, an address of a first sector of a block must be a multiple of 16. More specifically, an address of a first sector of a block must be XXX0
h
, and an address of the last sector in the same block must be xxxF
h
(xxx is an arbitrary hexadecimal number). In the 2-kilobyte external link method, the link part is provided outside the block. Thus, in order to give an address which is a multiple of 16 to a first sector of a block, an address cannot be assigned to the link part. That is, a link part which is not given an address exists between adjacent blocks. As a result, when data is recorded by the 2-kilobyte external link method, the sector address recorded with the user data shifts from the previously recorded LPP address. If such a shift occurs between the sector address and the PLL address at an arbitrary position on the DVD-RW medium, it is very difficult to calculate an address. Accordingly, there is a problem in that a recording or overwriting cannot be freely performed. Thus, although the 2-kilobyte link method is superior to other methods with respect to application to a conventional filing system, the 2-kilobyte external link method cannot be used in practice.
In a conventional recording method such as a disc-at-once method or an incremental write method, there is no link or the 0-kilobyte link, 32-kilobyte link or an internal link method using 2-kilobyte link is used. As a result, the sector address matches the LPP address. That is, a relationship between the sector address and the LPP address differs from the conventional recording method to the 2-kilobyte external link method. Thus, if an initial recording is performed by one of the methods, the same method must be used thereafter until whole recorded data is erased.
As a method for erasing recorded information on the DVD-RW, a physical erasing method or a logical erasing method may be used. In the physical erasing method, the recording pits are physically erased. In the logical erasing method, a specific pattern such as all-0 is recorded so as to substantially (logically) erase previously recorded pits. According to the nature of the DVD-RW, a service life of the DVD-RW can be longer when the logical erasing method is used than when the physical erasing method is used. As mentioned above, in the logical erasing method, an erasing pattern (erasing data) is recorded so as to erase recorded data, the sector address is recorded together with the erasing data. In order to facilitate address calculation, the sector address is recorded to match the LPP address so that the use of the DVD-RW after erasing becomes easy.
Generally, in an optical recording apparatus, when recording or overwriting is performed, a present address is recognized by reproducing both the sector address and the LPP address. Accordingly, there is a problem when data is recorded or overwritten on an erasing pattern by the 2-kilobyte external link method. This is because the erasing pattern is recorded according to the sector structure and the sector address matches the LPP address while the sector address of the sector recorded by the 2-kilobyte external link method shifts from the LPP address. Accordingly, when data is recorded or overwritten, the address of the previously recorded sector must be distinguishable from the LPP address so as to seek a target address from which the recording or overwriting operation is started.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved and useful optical recording method and apparatus in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide an optical recording method and apparatus which can record information on a rewritable recording medium having a pr
Dickstein , Shapiro, Morin & Oshinsky, LLP
Hindi Nabil
Ricoh & Company, Ltd.
LandOfFree
Optical recording method and apparatus for recording a link... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical recording method and apparatus for recording a link..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical recording method and apparatus for recording a link... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3051515