Abstract: A method and apparatus for initializing an optical recording medium comprising a phase change material using a series of flashes of light. A series of low-power, high duty cycle flashes of light are produced to initialize the media to a crystalline form, onto which data may be recorded. In accordance with another aspect of this invention, a spiral flash bulb with centrally located connectors comprises the flash illumination source for initializing the optical recording media.
Abstract: The present invention is a system for reading a CD having a surface with a multiple level data track including a laser, a focusing and positioning system configured in a way which causes the laser to follow the multiple level data track, a detector which converts the light which is reflected from the data track to an electrical signal, a digital signal processing unit configured to receive the electrical signal including a scaling-function generator for determining a plurality of signal windows from the electrical signal, and a multiple level analog to digital converter which determines a data level based on the signal windows and the electrical signal whereby multiple data levels may be read from the CD.
Type:
Grant
Filed:
January 5, 1996
Date of Patent:
December 29, 1998
Assignee:
Calimetrics
Inventors:
Bruce V. Johnson, Gregory A. McDermott, Michael P. O'Neill, Cezary Pietrzyk, Steven Spielman, Terrence L. Wong