| 摘要 |
PURPOSE: A sign board using the light of the sun is provided to select the power from a power supply unit and a solar cell module according to a time slot. CONSTITUTION: A solar cell module(13) supplies power to a display unit. A first controller(151) selects one of a power supply unit and the solar cell module and controls the supply of power to a display unit according to a time setting. A laser sensor(12) is combined with a body and detects the approach of a human body. The first controller use the solar cell module to supply power to the display unit. If the laser senor detects the human body, a second controller operates the display unit. |
