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:
Jan. 13, 1981
Filed:
Feb. 26, 1979
Jacob van den Berg, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A method of making a display screen for a color television display tube in which a photoconductive layer on the window portion of the tube is provided with a uniform charge which may be either positive or negative. A charge pattern is then formed on that layer by scanning it with an electron beam passing through an apertured color selection electrode. The energy of the beam is such that the average depth of penetration of the electrons is greater than the thickness of the photoconductive layer so that the charge disappears at the regions struck by the beam. The remaining charge pattern is developed with a suspension of charged phosphor particles. By repeating this process, patterns of red, green and blue luminescent phosphor particles can be successively provided to form the display screen. It is also possible to scan the layer simultaneously or successively by three electron beams and to develop the resultant charge pattern with a light-absorbing pigment.