Optical memory medium and its information recording and erasing method and apparatus

An information recording and erasing apparatus utilizing an optical memory medium comprising a substrate, a guard film, a recording material layer disposed between said substrate and said guard film, said recording material layer being heated by focused light to record information according to the focused light, and means responsive to a varying magnetic flux applied thereto for generating eddy currents for heating said recording material layer so as to enable at least one of recording of information on said recording material layer by the focused light and erasing of information from said recording material layer, said means for generating eddy currents being a good electrical conductor layer disposed between said substrate and said guard film, said apparatus comprising:

• magnetic flux generating means for supplying varying magnetic flux to said optical memory medium;
• and
• control means for controlling said magnetic flux generating means, said magnetic flux generating means supplying varying magnetic flux to said good conductor layer to generate eddy currents within said good conductor layer and heating said recording material layer with heat generated in said good conductor layer due to eddy current loss to effect information recording with the focused light and erasing with respect to said recording material layer.

An information recording and erasing method utilizing an optical memory medium comprising a substrate, a guard film, a recording material layer disposed between said substrate and said guard film, said recording material layer being heated by focused light to record information according to the focused light, and means responsive to a varying magnetic flux applied thereto for generating eddy currents for heating said recording material layer so as to enable at least one of recording of information on said recording material layer by the focused light and erasing information from said recording material layer, said means for generating eddy currents being a good electrical conductor layer disposed between said substrate and said guard film, said method comprising the steps of:

• supplying varying magnetic flux to said good conductor layer to generate eddy currents within said good conductor layer, and heating said recording material layer with heat generated in said good conductor layer due to eddy current loss and maintaining said recording material layer temperature below a recording transformation temperature;
• and
• recording information in accordance with the focused light.

An information recording and erasing apparatus utilizing an optical memory medium comprising a substrate, a guard film, a recording material layer disposed between said substrate and said guard film, said recording material layer being heated by focused light to record information according to the focused light, and means responsive to a varying magnetic flux applied thereto for generating eddy currents for heating said recording material layer so as to enable at least one of recording information on said recording material layer by the focused light and erasing of information from said recording material layer, said means for generating eddy currents being a good electrical conductor layer disposed between said substrate and said guard film, said apparatus comprising:

• means for supplying varying magnetic flux to said good conductor layer to generate eddy currents within said good conductor layer and for heating said recording material layer with heat generated in said good conductor layer due to eddy current loss and for maintaining said recording material layer below a recording transformation temperature;
• and
• focused light generating means for applying focused light onto said optical memory medium.