| 摘要 |
PURPOSE:To attain character recognition by amplifying a read signal by means of plural amplifiers with different gain using a read signal from a larger gain. CONSTITUTION:A reading magnetic head 3 scans relatively a card 1 at a prescribed position, reads a magnetic ink character and its reading signal becomes a differentiating waveform representing magnetic change amount. An output signal of the magnetic head 3 is amplified by an amplifier 4, fed to two amplifiers 6, 7 through a low pass filter 5 and amplified. Amplifiers with different gain are used for the amplifiers 6, 7. An output signal of the amplifiers 6, 7 is sampled and held in the same sampling interval as the same time by sample and hold circuits 8, 9 and subject to A/D convertion by A/D converters 10, 11. The result is fed to a microprosessing unit (MPU) 13 via a peripheral interface adapter (PIA) 12.
|
