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:
Nov. 12, 1991
Filed:
Jan. 02, 1990
Applicant:
Inventors:
Robert L Donofrio, Saline, MI (US);
Andre A Van der Voort, Son en Breugel, NL;
Assignee:
North American Philips Corporation, New York, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ;
U.S. Cl.
CPC ...
313474 ; 313112 ; 313466 ; 358 73 ; 427 68 ;
Abstract
The bulls-eye effect produced by projection television cathode ray display tubes with convexly curved faceplates and multi-layer interference filters is compensated by increasing the optical absorption of one of the filter layers having a decreasing center-to-edge thickness gradient. Since the layer is thicker in the center, more attenuation of the light output occurs there than at the edges of the display window, resulting in improved luminance uniformity of the display.