| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lighting device capable of illuminating bus route maps and time tables for easy viewing, while suppressing power consumption. <P>SOLUTION: A lighting device comprises: a solar cell 2; a rechargeable battery 3 charged with power from the solar cell; LEDs 4 which emit light by the power from the rechargeable battery 3; a human detection sensor 6 which detects the presence of people around it; a charging control circuit 7 which controls power supply from the solar cell 2 to the rechargeable battery 3; a dimming circuit 8 which controls power supply from the rechargeable battery 3 to the LEDs 4 so as to enable the LEDs 4 to emit light in brightness at multiple levels; and a control unit which controls the charging control circuit 7 and the dimming circuit 8 based on voltage of the solar cell 2, voltage of the rechargeable battery 3, and a human body detection signal from the human detection sensor 6. At night, the lighting device causes the LEDs 4 to emit light in a standby mode when the human detection sensor 6 does not detect the presence of people, and causes the LEDs 4 to emit light in an illumination mode, which is brighter than the standby mode, when the human detection sensor 6 detects the presence of people. <P>COPYRIGHT: (C)2012,JPO&INPIT |
