| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inexpensive hole code reader which can detect a tampered hole code surely. SOLUTION: A hole code 14 is formed by making a plurality of holes 15 in the side end face 13 of a core 11. The side end face 13 has black color and the bottom face of the hole 15 has white color. Two photosensors 21, 22 are positioned oppositely to the hole code 14. The first photosensor 21 is focused onto the side end face 13 and the second photosensor 22 is focused onto the bottom face of the hole 15 and an 'H' signal is delivered from the sensor when it faces a white face. Since a white part is present on the side end face 13 when an 'H' signal is delivered from the first photosensor 21, a decision is made that the hole code 14 has been tampered.</p> |
