| 摘要 |
PURPOSE:To reduce electric power consumption by controlling the lighting of an illuminating lamp of a liquid crystal display by the output of a photosensor and lighting the lighting lamp only when the ambient is dark. CONSTITUTION:The brightness of the ambience is detected with a photosensor 41, and the change in the quantity of light is converted to a change in resistance value, a change in voltage, a change in current, etc. and is fed as an input signal to a control device for an illuminating lamp. The voltage or current to be applied to an illuminating lamp 30 is controlled according to the brightness of the ambient to regulate the quantity of light of the illuminating lamp. In other words, the lamp 30 is lighted only when a level is measured in such a dark place where the display of a liquid crystal display 25 is illegible. |
