| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a lighting device capable of preventing degradation of solid light-emitting elements and deterioration of emission efficiency at normal times as well as at abnormal times. <P>SOLUTION: The device includes a lighting device structured of a current-limiting means 2 consisting of resistors R1 to R4, a transistor Q1, and a shunt regulator IC1, a current detecting means 3 made of a shunt regulator IC2, and an overcurrent-limiting means consisting of resistors R5 to R7, a transistor Q2, and a fuse F, and a light-emitting part 1 made by serially connecting light-emitting diodes LED1 to LED4. A load current I1 flowing in the light-emitting part 1 is limited by the current-limiting means 2 at normal times, and when abnormalities arise at the current-limiting means 2 due to failure or the like at a part of the circuit, the abnormalities are detected by the current-detecting means 3, and the load current I1 flowing in the light-emitting part 1 is shut off by the overcurrent-limiting means 4. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
