Patent ID: 6194848
Filing Date: 2001-02-27
Classification: H01J,H04N

Abstract:
An apparatus for automatically compensating for deflection of an electron beam in a cathode ray tube display due to an effect of earth's magnetic field (EMF), the apparatus comprising:detection means for detecting the EMF in response to EMF output control signals;a pulse generator for generating pulse signals with a predetermined frequency, the predetermined frequency corresponding to the EMF detected by the detection means;a counter for counting the pulse signals generated by said pulse generator at predetermined times to generate a gate signal;control means for receiving the gate signal generated by the counter and comparing the gate signal with a reference signal to generate a compensation value for the EMF, the control means further generating output state control signals for controlling an output state of the detection means; andprocess means for compensating for deflection of the electron beam in the cathode ray tube by the EMF in response to the compensation value generated by the control means.