| 摘要 |
PURPOSE: A dynamic focus circuit of a monitor is provided, so that a user can directly operate a predetermined key on a keyboard to control a screen focus as a required optimum state. CONSTITUTION: If a user controls a focus by operating a predetermined key on a user keyboard(11), a micro controller(MCU)(10) outputs a voltage control signal for changing a peak to peak value of a horizontal/vertical parabola signal. If the voltage control signal is inputted, a horizontal/vertical(H/V) processor(20) mixes a predetermined horizontal/vertical parabola signal with one parabola signal indicating a predetermined peak to peak value, and outputs the mixed signals. If the predetermined parabola signal output from the H/V processor(20) is inputted, an amplifying circuit(30) amplifies the parabola signal with a high-voltage parabola signal required in a cathode ray tube(CRT), and applies the amplified parabola signal to a dynamic focus pin, then controls a focus of a screen displayed on the CRT.
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