The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 1992
Filed:
Aug. 29, 1990
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A beam of light emitted from a light source and then modulated is focused through a write head onto a surface of a substrate which is coated with a photosensitive material and is rotated at a predetermined constant rotational speed. The write head and the substrate are displaced relatively in the radial direction of the substrate. While an optical axis of the beam of light is displaced in the direction in which the relative displacement speed between the write head and the substrate is decreased or increased, the substrate is exposed in such a way that a locus of a first turn or wind of predetermined tracks or pit arrays is recorded. Thereafter, while the substrate is rotated at the constant rotational speed, during the next rotation of the substrate the projection of the beam of light is interrupted and the optical axis of the beam of light is returned to its initial position. The above-described steps are repeated for recording the succeeding tracks or pit arrays, whereby a desired track pattern can be obtained.