CIRCUIT FOR PREVENTING PIN CUSHION OF PROJECTION TV

摘要

PURPOSE: A circuit for preventing pin cushion of projection TV is provided to prevent a degradation of pin cushion effectively by compensating for a horizontal size variation generated during an aging interval of a projection TV according to environmental temperature change. CONSTITUTION: A horizontal output pulse generation unit(210) lowers a horizontal output pulse inputted through a peripheral circuit to a constant proportion and outputs the horizontal output pulse. A power rectification unit(220) rectifies the horizontal output pulse into a DC(direct current) power. A reference voltage generation unit(230) outputs a reference voltage for controlling the DC power output from the power rectification unit(220) constant regardless of an outer power change to prevent a pin cushion. A reference voltage control unit(240) controls the reference voltage output from the reference voltage generation unit(230) according to environmental temperature. An E/W compensation signal input unit inputs a horizontal pin cushion compensation reference signal inputted through the peripheral circuit. A comparison unit(260) compares the reference voltage output from the reference voltage control unit(240) with the horizontal pin cushion compensation reference signal inputted to the E/W compensation signal input unit, and amplifies the difference value to output.