Dynamic information storage or retrieval – Storage medium structure – Optical track structure
Reexamination Certificate
1998-12-21
2002-07-23
Neyzari, Ali (Department: 2653)
Dynamic information storage or retrieval
Storage medium structure
Optical track structure
C369S059250, C369S053410
Reexamination Certificate
active
06424615
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to an optical disk capable of recording information according to the CD format with a greater recording capacity than the currently available 12 cm CD (Compact Disc), an optical disk recording device for recording information on this optical disk and an optical disk reproduction device for reproducing information from this optical disk.
Recording and reproducing time of the currently available CD is about 74 minutes at the maximum. Recording of a longer time can be made by increasing recording density or enlarging the diameter of the CD. Since, however, time information which can be expressed according to the subcode of the CD format is 99 minutes 59 seconds 74 frames at the maximum, some arrangement must be made if one wishes to record information of 100 minutes or more.
For example, Japanese Patent Application Laid-open No. Hei 7-262696 discloses an optical disk in which the recording surface area or portion of a single disk is divided in the radial direction into a plurality of areas each having a constant recording capacity, each divided area is constituted of a lead-in area, a program area and a lead-out area, and, in PSEC, PFRAME or ZERO of Q-channel subcodes in the first lead-in area or in an identification information area which is provided inside of the first lead-in area, identification information for identifying recording states of various information such as the number of the divided areas, number of combined areas, recording capacity of each divided area and TOC of each divided area is recorded. Absolute time information recorded in each divided area starts from a common initial value. A search operation for searching a particular position in a particular divided area is performed on the basis of detection of a position of an optical pickup in the radial direction of the disk (search in the divided area) and detection of absolute time information read from the disk (search in the divided area).
According to the device of the above described publication, since the recording capacity of each divided area is constant, in a case where recording of one program information is finished before the end of the divided area when a plurality of program information are to be recorded in the respective divided areas, there occurs a blank portion in the divided area where no effective information is recorded before a start position of a next divided area (i.e., recording start position for next program information) with the result that the recording capacity of the disk is not fully utilized.
Further, in a case where each divided area has a small recording capacity, identification of each divided area becomes difficult because of poor accuracy in detecting the position of the optical pickup in the radial direction with the result that, during a search operation, a divided area which is different from a designated divided area is erroneously searched. Again, when the optical pickup has erroneously entered an adjacent divided area due to skipping caused by a shock from outside, there is likelihood that such erroneous entering of the optical pickup is not detected and reproduction is continued from that position.
It is, therefore, a first object of the invention to enable full utilization of recording capacity in an optical disk in which the recording surface is divided into a plurality of areas and information is recorded in these divided areas by using absolute time information repeatedly, enable accurate searching of a designated divided area and enable returning of an optical pickup to a correct reproduction position when skipping of the optical pickup has occurred, and also to provide an optical disk recording device for recording information on such optical disk and also to provide an optical disk reproduction device for reproducing information from such optical disk.
There is another problem in the prior art optical disk. Minutes, seconds and frames of address information of the CD format are recorded in 2 digit BCD code and, accordingly, the maximum value of address information is 99 minute 59 second 74 frame. Therefore, even though a larger amount of information can be physically recorded in a single disk, such limitation in address information imposes a limit to an amount of information which can be recorded in a single disk. It is conceivable to use address information overlappingly among respective volumes but such arrangement will impair the function of address information designating only one address resulting in occurrence of trouble in an access operation (i.e., a wrong divided area is accessed in spite of the fact that a correct address is designated).
It is, therefore, a second object of the invention to provide an optical disk in which a large amount of information can be recorded without impairing the function of address information designating only one address, and also providing a reproduction device for reproducing this optical disk.
In case information such as a game software is recorded in a CD-ROM with a higher recording density than a standard recording density determined by the CD format, there will occur a case where it is desired to prevent reproduction of such game software by a standard CD-ROM player. In the past, there has not been such an optical disk or an optical disk reproduction device which can satisfy such demand.
It is, therefore, a third object of the invention to provide an optical disk in which restriction is imposed on information which can be reproduced by a standard reproduction device of the CD format and only the first volume can be reproduced by such standard reproduction device, and also to provide an optical disk reproduction device capable of reproducing all information contained in such optical disk.
SUMMARY OF THE INVENTION
For achieving the above described first object of the invention, there is provided an optical disk having a recording surface which is divided in the radial direction of the optical disk into a plurality of volumes each comprising a combination of a lead-in area, a program area and a lead-out area, each of these volumes having a recording capacity which is not constant and being adapted to have absolute position information recorded therein, said absolute position information consisting of time information starting from a common initial value, the lead-in area, the program area and the lead-out area of the respective volumes being adapted to have information of CD format recorded therein, and adapted to have volume number information corresponding to the volume number thereof recorded in a predetermined position of said area.
According to the optical disk of the invention, recording capacity of each volume (i.e., divided area) is not constant (i.e., is variable) and, therefore, by suitably setting the recording capacity of a particular volume in accordance with the capacity of a program to be recorded in this volume, waste of recording capacity can be eliminated and the recording capacity of the disk can be fully utilized. Further, by recording volume number information corresponding to respective volumes in a predetermined position of each format in the lead-in area, program area and lead-out area in the respective volumes, what number of volume is currently being reproduced can be accurately identified by reading out the volume number information from the disk during reproduction of the disk and a search operation can be carried out without mistake even when the recording capacity of the volume is relatively small. Furthermore, since the volume number information is recorded in all of the lead-in area, program area and lead-out area, the volume number can be accurately identified even if skipping of the optical pickup takes place and, therefore, the optical pickup can be restored to a position from which the optical pickup has skipped and reproduction of information can be continued from the restored position.
The volume number information may be recorded in, e.g., ZERO field of Q-channel subcodes. The volume number information may start from 0 or 1. Whe
Ishimura Yutaka
Murata Morihiro
Takeshita Kenichiro
Neyzari Ali
Pillsbury & Winthrop LLP
Yamaha Corporation
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