| 摘要 |
PURPOSE:To eliminate occurrence of reading error and to attain accurate data reading by binarizing an electric signal by an optical sensor and outputting binarized data for each dot from the number of dots between variation points and binary state. CONSTITUTION:Output signals of a CCD line sensor 1 are converted 2 to digital signals and irregularity of the quantity of light etc. is corrected by a quantity of light correcting circuit 3. Corrected signals are inputted to a binarizing circuit 4 and binarized, and distance between variation points is determined from addresses of variation points on the sensor 1, and binarized state at this distance is stored in a memory 5. A CPU 6 connected to the memory 5 divides the distance between variation points by number of elements of the sensor 1 corresponding to the size of 1 dot of the card, and changes the result of division to integer and calculates the number of dots at each variation point. Binary data for each dot written in tracks can be reproduced from the number of dots and binary state at this distance.
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