VERTICAL DEFLECTION S-SHAPED CORRECTION CIRCUIT AND VERTICAL DEFLECTION WAVE GENERATING METHOD

摘要

PURPOSE: To adjust vertical S-shape independently by generating a deflection wave subjected to S-shape correction while keeping a prescribed amplitude based on amplitude correction and an arithmetic formula of a deflected wave by an S-shaped correction wave amplitude detection circuit and a ramp waveform amplifier circuit. CONSTITUTION: A multiplier circuit 6 multiplies a sawtooth wave F of a basic waveform generated from a sawtooth wave generating circuit 5 twice and a 3-degree waveform obtained thereby is amplified by an amplifier circuit 7 depending on the necessity of S-shape correction to obtain an S-shape correction wave. An amplitude detection circuit 8 outputs a voltage in response to the amplitude of S-shape correction wave and a subtractor circuit 9 subtracts the voltage from a prescribed reference voltage to provide the output of an amplitude correction voltage V. A multiplier circuit 10 multiplies the sawtooth wave F with the voltage V to correct the amplitude and sets the reference voltage so as to be subjected to amplitude correction of the sawtooth wave F by the amplitudeαof the S-shape correction wave. Then the sawtooth wave F after correction and the S-shape correction wave are added by an adder circuit 11 to keep a prescribed amplitude and to generate a deflection wave subjected to S-shape correction. Thus, the S-shape correction is adjusted singly to improve the production efficiency.