Patent ID: 6226037
Filing Date: 2001-05-01
Classification: H04N

Abstract:
An AKB interface apparatus in a display system, comprising:a video signal processing IC having outputs coupled via respective kinescope driver ICs to respective kinescope cathodes for display of a color image, said signal processing IC having an input for receiving an AKB input signal, said driver ICs having respective outputs providing respective cathode current indicating signals; and an interface circuit, for coupling said cathode current indicating signals to the AKB input of said signal processing IC, said interface circuit comprising:a load circuit for generating a load voltage in response to at least one of said cathode current indicating signals;a leakage correction circuit responsive to said load voltage for applying a leakage correction current to said load circuit;said leakage correction circuit comprising a keyed comparator for comparing said output voltage of said load with a reference potential during a vertical retrace pulse interval to provide a leakage indicating signal;a controllable current source coupled to said keyed comparator and responsive to said leakage indicating signal for feeding back a leakage correction current to said load circuit; and filter means for coupling said leakage indicating signal to said controllable current source and for smoothing said leakage indicating signal.