Optical disk having read-exclusive and write-enable regions

• US 5,214,627 A
• Filed: 02/07/1990
• Issued: 05/25/1993
• Est. Priority Date: 02/08/1989
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Fujitsu Limited
• Inventors: Ogawa, Seiya, Nakashima, Kazuo, Hashimoto, Yasunobu, Maeda, Miyozo
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): Chevalier, Robert
• Application Number:
  US07/476,512
• Time in Patent Office: 1,203 Days
• Field of Search: 369/59, 369/54, 369/100, 369/58, 369/32, 369/47, 369/275.3, 369/284, 369/286, 369/272, 369/133, 369/240, 369/50, 358/342, 358/338
• US Class Current: 369/275.3
• CPC Class Codes: G11B 2220/211 Discs having both read-only and rewritable or recordable areas containing application data; Partial ROM media
• CPC Class Codes: G11B 7/24085 Pits

Abstract

An optical disk provided with read-exclusive regions where previously recorded information can be read, and with write-enable regions where information can be written. Information not desired to be rewritten can be recorded on the read-exclusive regions. The write-enable regions are open to users to freely add information thereto and to re-write information recorded. This optical disk can thus be used in various fields.

Claims

1. An optical disk, comprising:

a read-exclusive region on which information recorded according to a mark-length recording system is located on an inner edge of the disk in the radial direction thereof; and

a write-enable region, on which information is recorded and reproduced recording to a mark position recording system by a doubled recording of reproducing frequency used in the mark-length recording system that is located on an outer side of the disk in the radial direction thereof, the mark-length and mark position recording system are carried out while rotating the optical disk at a constant rotation angular velocity, thereby providing an optical disk having a storage capacitor per track of information recorded on said write-enable region which becomes equal to the storage capacity per track of information recorded on said read-exclusive region.

2. An optical disk, comprising:

read-exclusive regions; and

write-enable regions, said read-exclusive and write-enable regions are alternately and concentrically arranged on the disk distributed radially from an inner circumference to an outer circumference of the disk, information being reproduced from said read-exclusive regions according to a mark-length recording system and information being recorded on and reproduced from said write-enable regions according to a mark position recording system, the recording or reproducing frequency used in the mark position recording system is double that used in the mark-length recording system, the mark-length and mark-position recording systems conducted while rotating the optical disk at a constant rotational angular velocity, thereby providing an optical disk having a storage capacity per track of information recorded on said write-enable regions equal to that of information recorded on said read-exclusive regions.

6. An optical disk according to claim 2, wherein said write-enable region is provided on the side of said optical disk other than said read-exclusive region.

3. An optical disk, comprising:

read-exclusive regions; and

write-enable regions, said read-exclusive regions and said write-enable regions being alternately and concentrically arranged on the disk, distributed radially from an inner circumference to an outer circumference of the disk, information being reproduced from said read-exclusive regions according to a mark-length recording system and information being recorded on the reproduced from said write enable regions according to a mark position recording system, rotational angular velocity of the disk being employed when information is written on or erased from said write-enable regions according to the mark position recording system and is made lower than that employed when information is reproduced from said read-exclusive regions, and the recording frequency employed when information is recorded on or erased from said write-enable regions is set on the basis of the rotational angular velocities such that storage capacity per track on said write-enable regions becomes equal to that on said read-exclusive regions, a rotational angular velocity of the disk employed when information is reproduced from said write-enable regions is the same as that employed when information is reproduced from said read-exclusive regions, and the recording frequency used in the mark position recording system is double that used in the mark-length recording system.

7. An optical disk according to claim 3, wherein the recording frequency (fω

) employed when information is recorded on or erased from said write-enable regions is set to ##EQU1## where, fω

is the recording frequency employed when information is recorded on or erased from said write-enable regions fr is the recording frequency used in the mark-length recording system, η

ω

is the number of rotations used in the write-enable regions, and η

r is the number of rotations used in the mark-length region regions.

4. An optical disk, comprising:

read-exclusive regions; and

write-enable regions, said read-exclusive and write enable regions being alternately and concentrically arranged on the disk, distributed radially from an inner circumference to an outer circumference of the disk, information being reproduced from said read-exclusive regions according to a mark-length recording system and information being recorded on and reproduced from said write-enable region according to a mark-position recording, when information is to be recorded on said write-enable regions according to the mark position recording system, rotation control of the disk is carried out according to a multi-stage CAV method in which a rotational angular velocity is changed in several stages in accordance with a radial position of the disk, a variable controls a recording frequency employed when information is recorded on or erased from said writ-enable regions is conducted such that storage capacity per track of information recorded on said write-enable region becomes equal to that of information recorded on said read-exclusive region corresponding to information recorded on said write-enable regions;

each of said read-exclusive regions is followed by each of said write-enable regions, each of said read-exclusive regions is located at an inner portion from each of said write-enable regions, thereby constructing a pair including one of said read-exclusive regions and one of said write-enable regions having regions having equal storage capacity per track of information recorded, the storage capacity per track of information recorded is increased step-by-step as the radial position increases as a trigger when a linear velocity of the write-enable region of the radial position of the disk exceeds a predetermined value.

5. An optical disk according to claim 4 wherein the rotation angular velocity of the disk employed when information is read from the read-exclusive regions is identical to that employed when information is read from the write-enable regions.