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. 23, 2002
Filed:
Nov. 09, 2000
Charles Michael White, Escondido, CA (US);
William Adamson Lagoni, Indianapolis, IN (US);
Thomson Licensing S.A., Boulogne, FR;
Abstract
An emitter follower amplifier is coupled between the output of a high voltage video amplifier and the cathode of a kinescope for reducing the effective capacitance presented to the video amplifier that is attributable to the kinescope cathode, socket, spark gaps, and related stray capacitances. A secondary undesired capacitance loading of the video amplifier is effectively reduced by regulating the collector-emitter voltages of the emitter follower output transistors at substantially constant values thereby improving parameters such as slew rate and bandwidth of the overall video display system. Nonlinear circuitry in the follower circuit facilitates accurate AKB current sensing and provides simplification of the voltage regulation circuitry. White limiting circuitry is included within the video amplifier for reducing excess peak white drive that results in objectionable smears. Black limiting circuitry within the video amplifier is also provided to prevent the collapse of the collector-emitter voltage of the push-pull follower output transistor. The heat sink capacitance of the video amplifier output transistor is screened out via bootstrapping.