Patent ID: 6075687
Filing Date: 2000-06-13
Classification: H01J,H04N

Abstract:
An X-ray protection device for a monitor which comprises a cathode ray tube actuated by a high voltage from a transformer powered bv a power supply, said X-ray protection device comprising means for obtaining a signal from the transformer to represent the high voltage applied by the transformer to the cathode ray tube; a microprocessor which receives and processes the signal to give a processing result and a switching circuit which is connected to the microprocessor to be actuated by the microprocessor in response to the processing result to cut off the power supplied to the transformer so as to shut down the cathode ray tube; wherein the means for obtaining a signal from the transformer comprises a rectifier circuit which is coupled to a low voltage output of the transformer and receiving an alternate current signal from the transformer, the alternate current signal being rectified by the rectifier circuit, and a voltage division circuit which divides the rectified signal into an output signal within a predetermined voltage range.