Apparatus and method for controlling convergence of projection TV

Abstract

Disclosed is an apparatus for controlling a convergence of a projection TV. The apparatus has: a pattern generation unit to generate a reference pattern; a detection unit to output a detection signal in response to the variation of luminance of the reference pattern; a reference voltage generation unit to output a reference pulse voltage in regard to colors of RGB; a comparison unit to output a comparison signal of a wave-form output from the detection unit in response to the luminance and the reference pulse voltage; and a microprocessor to calculate a gain deviation based on the comparison result of the comparison unit, and control RGB signals to compensate the luminance up and down. The detection unit comprised of a plurality of photo sensors disposed on the screen detects the luminance of the reference pattern, the comparison unit compares the detection wave-form of the detection unit and the reference pulse voltage, and determines that the output wave-form is above a reference level. The luminance gain is automatically controlled when an earth magnetic field is compensated as the gain deviation of the luminance is detected by counting the number of pulse wave-form above the reference level, and the RGB signals are controlled in response to the gain deviation of the luminance. Therefore, the malfunction of the apparatus for controlling a convergence, which is occurred due to the luminance deviation can be prevented.

Dependencies are inferred from the claim text.