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:
Oct. 13, 1998
Filed:
Jul. 08, 1996
Presstek, Inc., Hudson, NH (US);
Abstract
A laser system for imaging graphic-arts constructions avoids the need to demagnify a divergent beam by using the output of a semiconductor or diode laser to optically pump a laser crystal, which itself emits laser radiation with substantially less beam divergence. A preferred implementation utilizes, as a pumping source, at least one laser device that emits in the IR, and preferably near-IR region, to image ablative or transfer-type printing members. The output of the pumping source is provided to the laser crystal via a focusing lens arrangement. The output of the laser crystal, in turn, is focused onto the surface of a recording medium to perform the imaging function. Crystal excitation and decay times are minimized by continuously maintaining the pumping source at a bias power level, which keeps the crystal at a continuous, baseline power level just short of lasing or imaging; and then selectively and intermittently increasing power to the pumping source to cause the crystal to lase (or lase at higher power) in an imagewise pattern. By selectively varying the pulse width within certain limits, it is possible to obtain image dots of different sizes while retaining a round dot shape.