Phase change type optical recording apparatus and optical recording method using an overwrite system
AssigneeKabushiki Kaisha Toshiba
InventorsHiroshi Hasegawa, Hiromichi Kobori
Life of this patent
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Abstract
An optical recording apparatus that rewrites recorded information on a modified constant angular velocity type phase change optical disk by overwriting using at least a recording light beam, erasing light beam and off-pulse light beam irradiation. The apparatus comprises a semiconductor laser for irradiating the optical disk with the light beam and a control unit for controlling the intensities P1, P2 and P3, wherein P1>P2>P3, of the light beam with which the optical disk is irradiated and their irradiation periods .tau.1 and .tau.3 to obtain a relation of {(P2-P3).times..tau.3}/{(P1-P2).times..tau.1}=below 1.
Claims19
An optical recording apparatus for recording information on a disk-like optical recording medium by irradiating the recording medium with a light beam of a first intensity P1 during a first irradiation period .tau.1 so as to form an amorphous state area at the recording medium and then irradiating the recording medium with a light beam of a third intensity P3 during a third irradiation period .tau.3 and irradiating the recording medium with a light beam of a second intensity P2 so as to form a crystal state area at the recording medium, comprising:
- light beam irradiating means for irradiating the optical recording medium with the light beam;
- and
- control means for controlling the intensities P1, P2 and P3 so that P1>P2>P3 and for controlling the irradiation periods .tau.1 and .tau.3 of the light beam to satisfy the following relation:
- {(P2-P3).times..tau.3}/{(P1-P2).times..tau.1}=below 1, and
- wherein the control means causes data indicative of the first intensity P1, the second intensity P2, the third intensity P3, and the irradiation periods .tau.1 and .tau.3 to be stored in at least one of an outer circumference portion and an inner circumference portion of the disk-like optical recording medium.
An optical recording method for recording information on an optical recording medium comprising the steps of:
- irradiating the recording medium with a light beam of a first intensity P1 during an irradiation period .tau.1 so as to form an amorphous state area on a recording area of the recording medium and then irradiating the recording medium with a light beam of a third intensity P3 during an irradiation period .tau.3 and irradiating the recording medium with a light beam of a second intensity P2, wherein P1>P2>P3, so as to form a crystal state area at the recording medium;
- enabling a latter half of the amorphous state area which is formed by irradiation with the light beam of the first intensity P1 and enlarged by irradiation with the light beam of the third intensity P3 to be crystallized by irradiation with the light beam of the second intensity P2 so that the latter half of the amorphous state area is erased;
- and
- storing data indicative of a first irradiation intensity P1, a second irradiation intensity P2, a third irradiation intensity P3, and irradiation periods .tau.1 and .tau.3 in at least one of an outer circumference portion and an inner circumference portion of the optical recording medium.
A method for recording and reproducing information on and from a zone constant angular velocity type phase change optical disk having a plurality of zones comprising the steps of:
- recording and reproducing information using at least a recording light beam, erasing light beam and off-pulse light beam, by varying at least an irradiation time of the recording light beam and an irradiation time of the off-pulse light beam in accordance with a respective recording zone of the optical disk;
- and
- recording and reproducing data indicative of irradiation intensities and irradiation periods of the recording light beam in at least one of an outer circumference portion and an inner circumference portion of the optical recording medium.
An optical recording apparatus for recording information on an optical recording medium comprising;
- a light beam generating unit;
- and
- a control circuit that causes the light beam to irradiate the recording medium at a first intensity P1 during an irradiation period .tau.1 so as to form an amorphous state area on the recording medium and then to irradiate the recording medium with the light beam at a third light intensity P3 during an irradiation period .tau.3 and to irradiate the recording medium with the light beam at a second intensity P2 so as to form a crystal state area at the recording medium, wherein an information recording area for recording the recording information and a recording condition recording area are disposed on the optical recording medium, the recording condition recording area being disposed on at least one of an outer circumference side and inner circumference side of the information recording area and storing therein recording condition data representing the intensities P1, P2 and P3, wherein P1>P2>P3, and irradiation periods .tau.1 and .tau.3 of the light beam, wherein P1, P2, P3, .tau.1 and .tau.3 satisfy the following condition:
- {(P2-P3).times..tau.3}/{P1-P2).times..tau.1)}=below 1.
An optical recording method for recording information on an optical recording medium comprising the steps of:
- detecting recording condition data from a recording condition recording area prior to recording information on the recording medium, the recording condition data being stored in a recording condition recording area disposed on at least one of an outer circumference side and an inner circumference side of an information recording area of the recording medium and representing intensities P1, P2, P3, wherein P1>P2>P3, and irradiation periods .tau.1 and .tau.3 of the light beam satisfying the following condition:
- {(P2-P3).times..tau.3}/{(P1-P2).times..tau.1}=below 1;
- and
- recording the information on the recording medium based on the recording condition data detected by the detecting step by performing the steps of:
- irradiating the recording medium with a light beam of a first intensity P1 during an irradiation period .tau.1 so as to form an amorphous state area at the recording medium,
- irradiating the recording medium with a light beam of a third intensity P3 during irradiation period .tau.3, and
- irradiating the recording medium with a light beam of a second intensity P2 so as to form a crystal state area at the recording medium.
An optical recording medium, comprising:
- an information recording area;
- and
- a recording condition recording area being formed on the optical recording medium, and the recording condition recording area being formed on at least one of an outer circumference side and an inner circumference side of the information recording area and stores therein recording condition data representing the intensities P1, P2 and P3, wherein P1>P2>P3 and irradiation period .tau.1 and .tau.3 of the light beam satisfying a condition
- {(P2-P3).times..tau.3}/{P1-P2).times..tau.1)}=below 1.
Dependencies are inferred from the claim text.