| 摘要 |
PROBLEM TO BE SOLVED: To prevent a head amplifier circuit from being complicated at the noise removel in the reading signal of a magnetic head by using a different reference signal with respect to a read-out signal, in which a very weak signal or noise is included, and realizing the exact read-out. SOLUTION: This circuit is furnished with the magnetic head 15 for performing the writing and reading operation of data with respect to a magnetic card, a writing circuit 21 for outputting the writing signal to the magnetic head, a reading circuit 24 for outputting the reading signal read out by the magnetic head, a noise removing circuit 25 for comparing the read-out signal with the reference signal to interrupt the signal having the level lower than that of the reference signal, and a reference signal producing circuit 27 for producing the reference signal, then the reference signal is produced as a reference voltage Vref with the reference signal producing circuit 27 in accordance with the voltage which a power source of the circuit is divided, and the voltage based on the writing data to be inputted to the writing circuit 21. COPYRIGHT: (C)2004,JPO
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