LASER DISCS SOFTWARE USED

Brand	Owner (click to sort)	Address	Description
COMPUTER DIMENSIONS	THE MCGRAW-HILL COMPANIES, INC.	1221 Avenue of the Americas New York NY 10020	laser discs and software used for classroom instruction in a variety of subjects at the high school level and instruction manuals therefor;COMPUTER;
COMPUTER DIMENSIONS	INTERNATIONAL THOMSON PUBLISHING, INC.	One Station Place Stamford CT 06902	laser discs and software used for classroom instruction in a variety of subjects at the high school level and instruction manuals therefor;COMPUTER;
	Where the owner name is not linked, that owner no longer owns the brand

Technical Examples

An optical system for an optical head of an optical disc drive is capable of using first and second discs, protective layer of the second disc being thicker than that of the first disc, a data density of the second disc being lower than that of the first disc. A light source selectively emits first and second laser beams having first and second wavelengths, respectively. An objective lens converges the first and second beams on the first and second discs, respectively. The second beam is incident on the objective lens as diverging light, and the first beam is incident on the objective lens as a beam of which degree of divergence is smaller. A diffraction lens structure is formed in the high NA exclusive area, which compensates for aberrations of a portion of the first laser beam, and causes aberrations to a portion of the second laser beam passed therethrough.