| 摘要 |
PURPOSE:To discriminate stably a storage medium by making a purely electrical discriminator for storage medium in stead of a conventional optical or mechanical reader. CONSTITUTION:When normal storage medium 1 is inserted to write device 5 and the input signal level is denoted as 0.5Vcc, outputs of voltage comparators 6 and 7 bececome H and low logical levels. Further, the output of comparator 7 is polarity- inverted in inversion circuit 8 to obtain a H-level output signal; and when they are supplied to AND circuit 9, the output logical value becomes H-level. Otherwise, when an abnormal storage medium is inserted and the value of resistance 4 is lower than the value of resistance R1 by 10% or more, outputs of voltage comparators 6 and 7 become L-level, and the output of AND circuit 9 becomes L-level also. As a result, it can be discriminated whether an inserted storage medium is normal or not by inspecting that the level of output OUT of AND circuit 9 is H or L logical level. |
