Patent ID: 7061192

Claim:
A switching-type vertical deflection output circuit comprising: an output-stage circuit in which the anode of a first diode is connected to the cathode of a second diode, the cathode of the first diode is connected to a first power supply, the anode of the second diode is connected to a second power supply as a reference potential or a low potential including negative voltage, and first and second switching elements are connected in parallel to the first and second diodes, respectively; a smoothing circuit which smoothes the voltage at the connection point of the first and second switching elements; a vertical deflection coil to which a smoothed voltage is supplied from the smoothing circuit; a unit which generates a vertical sawtooth voltage as a reference; a voltage conversion unit which converts a current flowing in the vertical deflection coil to a voltage; an error voltage generation unit which generates an error voltage between the vertical sawtooth voltage and a voltage converted by the voltage conversion unit thereto; a drive unit which controls the on/off operation of the first and second switching elements in the output-stage circuit by generating a drive pulse of a duty ratio in accordance with the error voltage from the error voltage generation unit; a pump-up circuit which pumps up the power-supply voltage of the first power supply to be supplied to the connection point of the first switching element and the cathode of the first diode in the output-stage circuit during the flyback period by detecting the level of the error voltage from the error voltage generation unit; and an impedance circuit which supplies a pump-up pulse generated based on the pump-up operation of the pump-up circuit to an input terminal for the conversion voltage from the voltage conversion unit in the error voltage generation unit.