| 摘要 |
PURPOSE:To prevent trouble due to miscontrol of density, by providing a manual density control system for control it to a desired value, and a reference density control system having a copying density preset, and properly selecting one of them. CONSTITUTION:A manual density control system A for controlling a density control circuit 1 through a variable resistance 2 and adjusting copying density to a desired value, and a reference density control system B for controlling a control circuit 1 through a fixed resistance group in order to control it to a preset density are installed. To make these control systems A, B selectable, they are connected to the control circuit 1 through switches SW1, SW2 of analog switches or the like. To control operation of the switches, a binary counter 6 for receiving a signal from touch swtiches provided with touch plates 4, etc. is installed, thus permitting trouble due to miscontrol of density to be prevented. |
