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:
Mar. 10, 1987
Filed:
Jan. 21, 1986
Thomas R Guerin, Hoffman Estates, IL (US);
Theodore V Lester, Schiller Park, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A scanning CRT control system is disclosed in which horizontal sync pulses are used to develop a pulse signal that provides an input to a transformer circuit also receiving a relatively low DC power supply input signal. The transformer circuit develops a very high DC voltage connected to a CRT screen while also providing a relatively lower voltage power supply signal that is utilized to develop the power supply signal provided to a video driver that controls beam excitation for the CRT. A compensation circuit is provided between the transformer circuit and a power supply terminal of the video driver such that a compensating signal is provided at the transformer circuit in accordance with each horizontal video scan line. The compensating signal has a frequency corresponding to the horizontal sweep frequency and a magnitude that varies in accordance with the average current loading of each individual horizontal scan line. In this manner the compensating signal will cause a variation in horizontal beam positioning so as to maintain horizontal orientation between different sequential horizontal scan lines regardless of the average beam current intensity of each of the horizontal scan lines. Preferably, the compensation circuit comprises a parallel resistor and capacitor connected in series between an output terminal of the transformer and the power supply terminal of the video driver.