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:
May. 27, 1980
Filed:
Jan. 19, 1978
Manfred R Kuehnle, Lexington, MA (US);
Ferdinand Martinez, Belmont, MA (US);
Stanley F Ignasiak, Holliston, MA (US);
Coulter Systems Corporation, Bedford, MA (US);
Abstract
A flexible offset printing plate is formed from a directly imaged electrophotographic member comprising an inorganic coating of a photoconductive material on a polyester substrate. The photoconductive material is an oriented crystalline deposit about 3000 Angstroms thick which has been directly sputtered with radiofrequency energy in a process using a Langmuir sheath to produce a light sensitive, readily imaged abrasion-resistant, transparent coating. It is deposited on a sheet of dimensionally stable, transparent polyester film having a thickness of about 0.005 inch with an intervening sandwiched layer of ohmic material such as indium-tin oxide about 300 Angstroms thick. The transparency of the ohmic layer and the photoconductive coating on a transparent substrate result in a transparent plate. The electrophotographic member is imaged by charging, exposure and toning with a suitable toner. The non-imaged parts of the surface are rendered hydrophilic (having a strong affinity for water and repellant to greasy ink) by suitable chemical and/or mechanical treatment while the imaged and toned parts are rendered hydrophobic (water-repellant and having a strong affinity for greasy ink). This may simply comprise choosing a type of toner which is inherently hydrophobic. The plate is mounted in an offset press and printing effected as though it were a conventional offset plate using the usual grease- or oil-based inks.