| 摘要 |
PURPOSE:To save unnecessary waste of papers and developer, by automating selection of a paper feed tray contining papers of desired size as soon as the power supply of a copying machine is switched on. CONSTITUTION:Upon switching on the power supply, S5 of the paper size detection switches of an upper paper feed tray is turned on and their S6 is turned off, and when S3 of paper size selection switches is turned on, RS-FF18, 19 are not set, and the output is left at 0. On the other hand, when the signal (f) of an initializing circuit 17 becomes 1, S7 of the paper size detection switches of a lower paper feed tray 8 is turned off, and their S8 is turned on, a size signal A3 is produced from a paper size detection circuit 13. Since the signal A3 coincides with a size signal A3' delivered from the switch S3' resulting in converting the output signal of an equality circuit 16 into 1, thus permitting the output of the FF18 to be made 0, that of FF19 to be made 1, a lower paper feed mechanism 9b to drive a paper feed roller 92, the paper 10 on the tray 8 to be fed, and the selection of the tray 8 to be indicated on an indicator 20. |
