US Patent 7420591 Optical detector of projection television

An optical detector is provided. The optical detector allows an auto-convergence control to be effectively made by cutting off external light incident to an optical sensor for use in the auto-convergence of a projection TV. The optical detector includes optical sensors and external light cut-off units. The optical sensors are positioned in an inside of the projection TV to receive test signals. The external light cut-off units are protruded to a direction to which the test signals are incident.