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EP0345752A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Optical information recording method and apparatus and recording medium used therefor

Assignee: Hitachi Ltd
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Filing: 1989-06-07
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Granted: —
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Expires: 2009-06-07
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Abstract

Abstract A method and apparatus for optically recording information in which the phase state of each recording position of the recording film of a recording medium such as an optical disk is reversibly changed between an amorphous phase and a crystalline phase using a single laser beam, thereby optically recording information on the recording film. The recording position on the recording film is heated to the melting point thereof or more through laser beam irradiation irrespectively of the information to be recorded. After completion of the heating, in order to change the phase state of the recording film at the recording position in accordance with the information, the power and/or irradiation time of the laser beam is controlled so as to provide different times required for the temperature of the recording position to pass the crystallization temperature region of the recording film. The recording medium has at least one record of data indicative of the melting point of the recording film and data indicative of the time required to pass the crystallization temperature region for placing the recording position in the amorphous or crystalline state.

Inventors

  • 👤 Norio Goto
  • 👤 Masaji Ishigaki
  • 👤 Yukio Fukui

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-02 09:38
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/03; G11B7/00; G11B7/12; G11B7/125; G11B7/126; G11B7/004; G11B7/006; G11B7/24

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 171 words
A method for optically recording information wherein a laser beam emitted from a laser light source is irradiated to a recording film of a recording medium to heat a recording position of the recording film so that the phase state of the recording position is selectively changed in accordance with a predetermined heating condition to an amorphous state and a crystalline state corresponding to the information to be recorded, thereby directly overwriting new information on the recording film without experiencing a process dedicated to erasing, a method for optically recording optical information, comprising the steps of: heating (102) the recording film at the record­ing position by said laser beam to the melting point or more independently of information to be recorded; and changing (103) the time required for the temperature of said recording position to pass a crystallization temperature region of said recording film in accordance with the information to be recorded, thereby selectively changing of the phase state of said recording position between the amorphous state and the crystalline state.
Claim 2
Independent Claim 171 words
A method for optically recording information wherein a laser beam emitted from a laser light source is irradiated to a recording film of a recording medium to heat a recording position of the recording film so that the phase state of the recording position is selectively changed in accordance with a predetermined heating condition to an amorphous state and a crystalline state corresponding to the information to be recorded, thereby directly overwriting new information on the recording film without experiencing a process dedicated to erasing, a method for optically recording optical information, comprising the steps of: heating (102) the recording film at the record­ing position by said laser beam to the melting point or more independently of information to be recorded; and changing (103) the time required for the temperature of said recording position to pass a crystallization temperature region of said recording film in accordance with the information to be recorded, thereby selectively changing of the phase state of said recording position between the amorphous state and the crystalline state.
Claim 3
Dependent Claim 158 words
A method for recording optical information according to claim 1, wherein in the case (505) where the information represented by the amorphous state is to be recorded to the recording position, power of said laser beam to be irradiated to the recording position is set at first irradiation power P₁ for heating said recording film to a first temperature T₁ of the melting point thereof or more, whereas in the case (506) where the information represented by the crystalline state is to be recorded to the recording position, power of said laser beam to be irradiated to the recording position is set at second irradiation power P₂, which is lower than first irradiation power P₁, for heating said recording film to a second temperature T₂ of the melting point or more, which is lower than said first temperature T₁, whereby the time required for the temperature of said recording position to pass said crystallization temperature region is changed.
Claim 4
Dependent Claim 109 words
A method for recording optical information according to claim 1 wherein in the case (1505) where the information represented by the amorphous state is to be recorded, the irradiation time of said laser beam is at a first irradiation time t p1 , whereas in the case (1506) where the recording position information represented by the crystalline state is to be made crystalline, the irradiation time of said laser beam is at a second irradiation time t p2 , which is longer than the first irradiation time t p1 , whereby the time required for the temperature of said recording position to pass said crystallization temperature region is changed.
Claim 5
Dependent Claim 135 words
A method for recording optical information according to claim 2, in the case (703) where the information represented by the amorphous state is to be recorded, said laser beam is set at said first irradiation power P₁ and the irradiation time of said laser beam is set at a first irradiation time t p1 , whereas in the case (704) where the recording position is to made information represented by the crystalline state is to be recorded, said laser beam is set at said second irradiation power P₂ and the irradiation time of said laser beam is set at a second irradiation time t p2 , which is longer than the first irradiation time t p1 whereby the time required for the temperature of the recording position to pass said crystallization temperature region is changed.
Claim 6
Independent Claim 156 words
An apparatus for optically recording information comprising: optical pick-up means (193) having a laser light source for applying a single laser beam to a recording position in a recording film of a recording medium; laser driving means (194) for driving the laser light source in said optical pick-up means; moving means (195) for relatively moving said recording medium and said optical pick-up means; and system control means (196) for controlling said moving means and also controlling said laser driving means on the basis of predetermined information, said system control means having passing time control means (197) for said laser driving means so as to heat said recording position of the film to the melting point of the recording film irrespectively of information to be recorded and thereafter controlling the time required for the temperature of the recording position to pass the crystallization temperature region of the recording film in accordance with said information to be recorded.
Claim 7
Independent Claim 156 words
An apparatus for optically recording information comprising: optical pick-up means (193) having a laser light source for applying a single laser beam to a recording position in a recording film of a recording medium; laser driving means (194) for driving the laser light source in said optical pick-up means; moving means (195) for relatively moving said recording medium and said optical pick-up means; and system control means (196) for controlling said moving means and also controlling said laser driving means on the basis of predetermined information, said system control means having passing time control means (197) for said laser driving means so as to heat said recording position of the film to the melting point of the recording film irrespectively of information to be recorded and thereafter controlling the time required for the temperature of the recording position to pass the crystallization temperature region of the recording film in accordance with said information to be recorded.
Claim 8
Dependent Claim 159 words
An optical information recording medium comprising: a substrate (11) having a tracking guide; a recording (13) film provided on said substrate, said recording film being heated by a laser beam supplied from the outside so as to reach the melting point thereof or more and thereafter passing the tempera­ture of said films through a predetermined temperature region with a predetermined passing time so that said recording film changes its phase state between an amorphous state and a crystalline state indicative of information to be recorded; a protection film (16) for sealing said recording film; and a track (232) on which at least one of data indicative of the melting point of the recording film, a first passing time data indicative of the passing time data indicative of the passing time required for the recording film to become amorphous, a second passing time data indicative of the passing time required for the recording film to become crystalline is previously recorded.
Claim 9
Dependent Claim 159 words
An optical information recording medium comprising: a substrate (11) having a tracking guide; a recording (13) film provided on said substrate, said recording film being heated by a laser beam supplied from the outside so as to reach the melting point thereof or more and thereafter passing the tempera­ture of said films through a predetermined temperature region with a predetermined passing time so that said recording film changes its phase state between an amorphous state and a crystalline state indicative of information to be recorded; a protection film (16) for sealing said recording film; and a track (232) on which at least one of data indicative of the melting point of the recording film, a first passing time data indicative of the passing time data indicative of the passing time required for the recording film to become amorphous, a second passing time data indicative of the passing time required for the recording film to become crystalline is previously recorded.

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