| 摘要 |
PURPOSE:To inform to a user of a fact that a variation of an operating state of an apparatus is not caused by a fault of the apparatus, in case when it occurs due to a drop of power-supply voltage, by checking the power-supply voltage in a copying machine, etc., and displaying a state of an electric power supply by use of a color corresponding to its voltage. CONSTITUTION:When transistors TR1-TR4 in a display control unit DCU connected to a port of a processor conduct, each resistance value R6-R9 is set so that currents of 20, 10, 7.5 and 5mA are made to flow to a blue light emitting diode 40a or a multi-color light emitting diode 40b, respectively. The LED 40a emits blue light of a prescribed light quantity by a driving current of 20mA, and the LED 40b emits green light by a driving current of 10mA, red light by a driving current 5mA, and emits orange light by a driving current of 7.5mA between both of them. Accordingly, a color of display is changed by magnitude of voltage inputted to ports D1-D4, and supply voltage is confirmed, therefore, it is not mistaken for a fault of an apparatus. |
