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:
Jul. 13, 1982
Filed:
Jan. 25, 1978
Applicant:
Inventors:
Jan van der Waal, Eindhoven, NL;
Gerard Vermeulen, Eindhoven, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
G03C / ;
U.S. Cl.
CPC ...
430 24 ; 313403 ;
Abstract
A method of manufacturing a pair of associated reproduction masks for manufacturing shadow masks for display tubes. In order to obtain elongate apertures which are enlarged in width on the side of the mask facing the screen, the second reproduction mask is formed by reproducing the first reproduction mask on a photographic plate by means of light rays which have a substantially greater divergence in a plane perpendicular to the long dimension of the apertures than in the plane parallel thereto.