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:
May. 01, 2001
Filed:
Dec. 30, 1998
Dal Frank Griepentrog, Indianapolis, IN (US);
Thomson Licensing S.A., Boulgne Cedex, FR;
Abstract
An AKB interface apparatus in a display system (,), includes a video signal processing IC (,) having outputs coupled via respective kinescope driver ICs (,) to respective kinescope cathodes (K,,K,,K,) for display of a color image, the signal processing IC having an input,for receiving an AKB input signal, the driver ICs having respective outputs (,) providing respective cathode current indicating signals (RP,GP,BP) An interface circuit (,) couples the cathode current indicating signals to the AKB input of the signal processing IC. The interface circuit comprises a load circuit (,) for generating a load voltage (Vo) in response to at least one of the cathode current indicating signals. A leakage correction circuit (,), responsive to said load voltage (Vo), feeds back a leakage correction current (Io) to the load circuit. The leakage correction circuit includes a keyed comparator (Q,,Q,,Q,) for comparing the output voltage of the load (,) with a reference potential during a vertical retrace pulse interval to provide a leakage indicating signal; and a controllable current source (Q,,Q,) is coupled to the keyed comparator and responsive to the leakage indicating signal for feeding back the leakage correction current (Io) to the load circuit (,). In one application the cathode current indicating signals are first combined (,) and then subjected to leakage compensation (,) for application to the processing IC AKB input. In another application, the cathode current indicating signals are individually leakage compensated and then combined (,) for application to the processing IC.