| 摘要 |
PURPOSE:To prevent light printing by informing the shortage of toner even at the operation stop indicating switch operation of a laser printer. CONSTITUTION:When the residual mount of toner in a developper is less, a switch 1 which indicates the operation stop of a laser printer is connected to a contact B to replace the print paper to another paper and an FF8 is set. Thus, the output of an OR gate applied with the paper end signal is at high level, an AND gate 11 is opened and an FF9 is set with a high level signal due to less residual toner. Then, a lamp 16 illuminates via a driver 15 and a toner empty is displayed. Thus, even if the paper end signal is not produced due to replaced paper, the toner empty is displayed, allowing to avoid light printing. |
