| 摘要 |
<p>PURPOSE:To detect a malfunction, by using a current obtained by cutting a photocurrent, which is cut at the threshold level as an input current which is generated by light passes through the punched hole for detection of malfunctions provided in the trailing edge part or the like of an information medium. CONSTITUTION:A punched hole for detection of malfunctions is provided for every bit in the trailing edge or the like of an information medium, and photocurrent obtained by cutting said current at the threshold level which pass through these holes are used as input currents. Input lines of 12 input currents expressed by R, X, O, 1-9 are input to OR gate circuits 1 three by three. Outputs A-D of these circuits 1 are input to an AND gate 3. The output E of the circuit 3 is input to a malfunction detecting pulse generating circuit 4 to generate a pulse F. Meanwhile, input lines of 12 pieces of input signals are input to an OR gate circuit 2 to output an output G. The pulse F and the output G are input to an AND gate circuit 5, and a pulse H is generated only when a malfunction occurs. The pulse H is input to an FF6, and a signal I indicating the occurrence of the malfunction is output to the output side.</p> |
