Browse Prior Art Database

Beam Multiplication for Erasing Optical Phase-Change Recording

IP.com Disclosure Number: IPCOM000059781D
Original Publication Date: 1986-Jan-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Cohen, DK: AUTHOR [+2]

Abstract

Phase-change media, such as media changing between an amorphous and a crystalline state, requires a slow heating and cooling process for erasing recorded data. An elliptical collimated beam passes through a sinusoidal grating and a focusing lens which divides the elliptical beam into a plurality of smaller elliptical beams along a given line. The effect of the beam division is to provide a low-intensity elongated series of small elliptical beams which enable erasing of any data recording in a phase-change record medium. The sinusoidal variations within the grating are disposed along the same line as the beam is elongated. A solid-state laser supplies an elliptical beam to a sinusoidal grating which is constructed using known techniques.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 70% of the total text.

Page 1 of 2

Beam Multiplication for Erasing Optical Phase-Change Recording

Phase-change media, such as media changing between an amorphous and a crystalline state, requires a slow heating and cooling process for erasing recorded data. An elliptical collimated beam passes through a sinusoidal grating and a focusing lens which divides the elliptical beam into a plurality of smaller elliptical beams along a given line. The effect of the beam division is to provide a low-intensity elongated series of small elliptical beams which enable erasing of any data recording in a phase-change record medium. The sinusoidal variations within the grating are disposed along the same line as the beam is elongated. A solid-state laser supplies an elliptical beam to a sinusoidal grating which is constructed using known techniques. The sinusoidal grating supplies a modified elliptical beam to a focusing lens disposed from a record medium by its focal length. The periodicity of the sinusoid in the grating multiplied by the focal length of the focusing lens determines the center spacing of the erasing spots projected on a record medium disposed at the focal length from the focusing lens. An additional sinusoid can be superposed in the grating over a first sinusoid frequency for adding more erasing spots and thereby reducing a maximal intensity of the erasing spots. As more frequencies are added to the sinusoidal grating, the length of the erasing spot is also increased with a corresponding decrease...