| 摘要 |
An LED illumination device (10) that can be mounted between a pair of sockets (32, 32) provided to a fluorescent light fixture is provided with a first power source circuit that illuminates an LED using DC power obtained by converting and rectifying AC power supplied from the sockets, and a second power source circuit that illuminates the LED using an internal battery. When the illumination device is mounted between the pair of sockets, an IC chip (33) installed in the illumination device detects a first current conduction state in two AC power lines (29, 31) that supply the AC power necessary to drive the first power supply circuit and a second current conduction state in another AC power line (31), and, on the basis thereof, determines that the device is in a normal illumination mode (a) when both current conduction states are current-conducting states, determines that the device is in a normal off mode (b) when the first current conduction state is a non-current-conducting state and the second current conduction state is a current-conducting state, and determines that the device is in an emergency illumination mode (c) when both current conduction states are non-current-conducting states. On the basis of the determination results, the LED illumination device is controlled according to the mode. When in the emergency illumination mode, the LED is illuminated by the second power source circuit, and the LED illumination device functions as an emergency light. |
