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. 04, 1977
Filed:
Nov. 26, 1975
Theodore Frederick Simpson, Lancaster, PA (US);
RCA Corporation, New York, NY (US);
Abstract
In a multi-beam color display tube, having a screen on which phosphor deposits are disposed which are impinged upon by the electron beams so that they luminesce with different colors, one electron beam at a time is activated and scanned while the picture to be displayed is a blank raster. A special post-deflection coil introduces magnetic fields in the region just forward of a deflection yoke to displace the scanned beams in a controlled pattern from their normal landing points on the screen while photosensors measure the light from each color deposit at a plurality of measurement locations on the screen. The displaced beam causes the emission of an error color, the intensity of which is measured by those photosensors which are sensitive to the error color emitted. The intensity of a reference color emitted by the phosphor deposits stimulated by the undisplaced electron beam is then measured. The ratio of the error color to the reference color is then calculated for each measurement location with the largest ratio being displayed as an indication of the color purity tolerance of the tube.