Patent ID: 6614482
Filing Date: 2003-09-02
Classification: H04N

Abstract:
A video signal processing apparatus, comprising:a video signal input connected to a source of video signals for receiving a video input signal; a video signal output connected to a selected cathode of an image reproducing device for providing an output signal, said selected cathode having a cathode current flowing therethrough in response to said output signal; means, coupled between said video signal input and said video signal output, for amplifying said video input signal to form said output signal, said amplifying means including a driver amplifier; means, coupled to said selected cathode, for sensing said cathode current, said sensing means providing a first signal representative of said cathode current flowing in said selected cathode; and means, directly coupled between said sensing means and said amplifying means, for providing a feedback signal to said driver amplifier, said feedback signal being responsive to said first signal, said feedback signal limiting an output from said driver amplifier to an output level, thereby limiting said output signal to a predetermined level when said cathode current exceeds a cathode current level, said drive amplifier comprising a common emitter amplifier transistor coupled in a cascode driver amplifier configuration with an output common base amplifier transistor, said cascode driver amplifier being coupled to an emitter follower amplifier, said emitter follower amplifier stage having an output coupled to said image reproducing device.