Method and device for compensating the horizontal scanning size

Abstract

A compensation control circuit of horizontal scanning size suitable to be used in a general monitor to compensate the variation amount of horizontal scanning size due to the influence of the anode load current. The compensation control circuit includes two parts: One is the horizontal scanning size compensation circuit and the other is the horizontal scanning size control circuit. The horizontal scanning size compensation circuit is coupled to the coil of the fly-back transformer to generate a corresponding compensation signal according to the variation of the anode load current. The compensation signal is far lower than the level of the anode voltage. Therefore, it can be processed by the general electric circuits. The horizontal scanning size control circuit is coupled to the horizontal scanning size compensation circuit to receive the compensation signal. The compensation signal can combine with the shift regulation signal sent by the microprocessor to be a D.C. modulation signal. Then the D.C. modulation signal combines with the A.C. modulation signal to generate the modulation voltage. Because the modulation voltage of the another terminal of the horizontal deflection yoke contains the D.C. compensation signal factor, the modulation voltage will compensate the influence of the horizontal scanning size due to the variation of the anode voltage when the anode load current changes.

Dependencies are inferred from the claim text.