| 摘要 |
PROBLEM TO BE SOLVED: To provide a disconnection detecting circuit which can detect disconnection of a light-emitting element, while realizing low cost and miniaturization, and high reliability is maintained. SOLUTION: The disconnection detecting circuit comprises a light-emitting element (LED), a current control means connected to the light-emitting element for controlling current which flows to the light-emitting element (transistor TR<SB>1</SB>), a control signal transmitting means for transmitting a control signal to the current control means (LED lighting control circuit 12), and a detecting means for detecting the existence of the potential level variation of the light-emitting element (detecting circuit 14). The detection means detects an open circuit of the light-emitting element, by detecting the existence of the potential level variation of the light-emitting element, when the signal level of the control signal varies. COPYRIGHT: (C)2008,JPO&INPIT
|
