| 摘要 |
<p>PURPOSE:To obtain many key codes and improve the reliability without being influenced by the using circumstances by providing a key holding part with a light receiving part, a light emitting part and a coding means, as well as a lock main body with a light emitting means, a light receiving means and a code discriminating means respectively. CONSTITUTION:Photoelectric transfer components 11, 12 facing the light emitting end 13a and the light receiving end 14a of the light conducting members 13, 14 buried in an outer casing 4 respectively and a pulse code modulation circuit 9 connected to these photoelectric transfer components 11, 12 are provided in a key holding part 8. When a key 5 is inserted into a key hole 6, the fixed pulse light is injected from the light emitting end 13a by means of the emission circuit 19 of a lock main body, and the pulse light becomes coded electric signals by means of the pulse code modulation circuit 9. These electric signals are converted into light signals and injected into the light receiving end 14a from the photoelectric transfer component 12. These output signals are further compared to the set code signals in a code discriminating circuit 22 through a light receiving circuit 20, and the coincidence of the signals results in unlocking.</p> |
