Dynamic information storage or retrieval – Information location or remote operator actuated control – Selective addressing of storage medium
Reexamination Certificate
2001-05-10
2004-02-17
Psitos, Aristotelis M. (Department: 2653)
Dynamic information storage or retrieval
Information location or remote operator actuated control
Selective addressing of storage medium
C369S047380
Reexamination Certificate
active
06693855
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical on and from which data is recorded and reproduced, and to an optical apparatus that uses the optical as a recording medium.
2. Description of the Related Art
Optical discs, generally known as “compact discs,” are used in increasing numbers. Each optical comprises a resin substrate that is about 120 mm in diameter and about 1.2 mm in thickness. The substrate has a signal-recording surface having recording areas, in which digital data is recorded. The digital data has been subjected to error correction performed by using CIRCs (Cross Interleave Reed-Solomon Codes) or to EFM (Eight-to-Fourteen Modulation).
Compact discs (hereinafter referred to as “CDs”) were developed first as media for recording digital audio data. As they are commonly used in increasing numbers, they are now put to various uses.
Particularly in recent years, optical discs for reproducing only called “CD-ROM (Read-Only Memory) have come into common use. This is because personal computers are now used in many households as information-processing apparatuses, and CD-ROMs are used as media to record the information processed by the personal computers.
Optical discs of other types, which can record data recorded on the reproduction-only optical discs such as CD-ROMs, have been developed and come into practical use. They are recordable optical discs called “CD-R (Recordable)” and rewritable optical discs known as “CD-RWs.”
Hereinafter, the CDs (Compacts) and the other optical discs derived from the CDs shall be generally referred to as “CD-families.” The recording areas of each CD-family, in which data may be recorded, have a physical address each. The physical address indicates the position of the recording area. To record data in a target recording area or reproduce data therefrom, the optical head of an optical apparatus makes an access to the target recording area in accordance with the physical address of the recording area.
The access of the optical head to the target recording area is controlled by the controller incorporated in the optical apparatus. The controller calculates the distance the optical head should move to reach the target area, from the physical address of the target area. The optical head is moved in the radial direction of the CD-family for the distance the controller has calculated. The optical head can therefore make an access to the target recording area of the CD-family.
The physical address of each recording area of any CD-family is written in the Q channel of the subcode that is contained in the data recorded on the recording area. In a CD-ROM developed for the purpose of recording computer data and the like, the physical address of each recording area is written not only in the Q channel of the subcode, but also in the starting part of user data, called “block header.” In a CD-R or a CD-RW on which data can be recorded, the physical address of each recording area is written not only in the Q channel and block header of the subcode, but also in the wobbling groove that is made in the surface of the substrate.
In the CD-familys of the existing format, the physical address of each recording area is written in the MSF (Minutes: Seconds: Frames). This is because CDs were developed in order to record digital audio data, which is best handled if the physical addresses of the recording areas are time-axis data.
Thus, in a CD-family of the existing format, the MSF-format physical address is set at the minimum value of “00 (minute): 00 (second): 00 (frame),” for the starting position of the program area which is the innermost user-data area of the disc. The MSF-format physical address of the recording area next to the program area has an MSF-format physical address set at a greater value. The farther each recording area is located from the starting position of the program area, the greater the value its MSF-format physical address has.
A TOC (Table of Contents) is written in the read-in area and the like that are provided on the center part of each CD-family, for recording data other than the user data. Of these areas provided on the center part of the disc, the innermost one that is immediately adjacent to the above-mentioned program area has the value of “99 (minutes): 59 (seconds): 74 (frames),” which is the maximal in the MSF format. In the center part of the disc, the farther each area is located from the center of the disc, the greater the value its MSF-format physical address has. The value of a physical address changes from the maximum to the minimum, and vice versa, at the starting position of the program area.
Since physical addresses are set as described above, the physical address of the starting part of user data is represented by time-axis data of “00 (minute): 00 (second): 00 (frame).” This scheme of setting of physical addresses is very useful in the case where the user data is, for example, audio data.
If physical addresses are set as indicated above, however, the value of a physical address changes from the maximum to the minimum, and vice versa, at the starting position of the program area. To move the optical head from any program area to the center part of the disc, or vice versa, to reach any target position on the disc, complex calculation is required to find the distance the optical head must move, from the physical addresses of recording areas. Consequently, it would take much time to calculate the distance.
A double-density CD format is now studied, which is compatible with the exiting CD format and which can increase the storage capacity of a CD twice as much as that of the existing CD format. It is proposed that, in the double-density CD format, a higher unit of time, i.e., hour, be added to the MSF-format physical address, to provide an HMSF (Hour; Minutes: Seconds: Frames) format. If the physical addresses are so set in the double-density CD format, however, more complex calculation is required to find the distance the optical head should move from any program area to the center part of the disc, or vice versa, to reach any target position on the disc. This may greatly increase the time the optical head needs to make an access to the target recording area.
BRIEF SUMMARY OF THE INVENTION
The present invention has been made in view of the foregoing. An object of the invention is to provide an optical disc with which it is easy to calculate the distance an optical head should move to any target recording area, thus achieving a fast access to the target recording area. Another object of the invention is to provide an optical disc apparatus that uses such an optical disc as a recording medium.
According to the first aspect of the present invention, there is provided an optical disc that has a recording surface including a program area for recording user data and auxiliary recording areas for recording data other than the user data; and a spiral track provided in the recording surface, wobbling at a predetermined frequency and defining wobble information. The wobble information represents physical addresses of the recording areas, the value of which gradually increases from the innermost part of the disc toward the outermost part of the disc, over the entire radius of the recording area.
According to the second aspect of the invention, there is provided an optical disc that has a recording surface including a data area for recording program data and a read-in area provided inside the data area. In the optical disc, the physical address of each recording area provided in the recording surface is recorded in both the first format that is time-axis data and the second format that is binary data. The value of the physical address gradually increases from the innermost part of the disc toward the outermost part of the disc, over the entire radius of the recording area, while the first format and the second format remains in one-to-one correspondence.
According to the third aspect of the invention, there is provided an optical disc apparatus that comprises: a motor for rotating a
Kawashima Tetsuji
Miyake Kunihiko
Shishido Yukio
Tsukada Futoshi
Maioli Jay H.
Psitos Aristotelis M.
Sony Corporation
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