PURPOSE: To prevent a key from being broken easily by preventing a key opening/closing control circuit from being activated unless a certain amount of time passes in the case when a received code does not coincide with a preset code.
CONSTITUTION: A data code from a data code-setting circuit 1 is coded by a transmission circuit 2, is modulated, is changed into a light signal by a light- emitting diode 3, and is transmitted. The transmitted light signal is received by a photo diode 4, is demodulated by a data-reading circuit 5, and is compared with a data code from a data code-setting circuit 6 by a comparison circuit 7. When both of them coincide with each other, a control circuit 8 releases a key 9. When both of them do not coincide with each other, a timer 10 starts counting, thus preventing the control circuit 8 from operating unless a certain amount of time passes, even if the key code coincides, namely preventing the key 9 from opening.
| JP3350632 | [Title of Invention] Anti-theft device for vehicles |
| JP4823492 | Automatic door device |
| JPH05314399 | GATE OPENING/CLOSING CONTROL SYSTEM |
SUDA SHINJI
HONGO KATSUNOBU
