| 摘要 |
A horizontal frequency correction circuit counts the horizontal synchronous signal with the external clock and controls the speed of a drum motor by the analog signal converted from the counting value. The circuit comprises a noise mask circuit (20) receiving the horizontal sync. signal in response to the control signal from a control signal generator (10), a clock signal control section (30) for producing the clock signal in response to the control signal from the noise mask circuit, a sample and hold circuit (50) for sampling the output of 8 bit counter (40), a D/A converter (60) for converting the output of the sample and hold circuit and driving the drum motor, and a noise mask control circuit (70) for disabling the noise mask circuit.
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