| 摘要 |
PURPOSE:To omit the installation of a mode changing switch to expand a space on an operation panel and to reduce the cost of parts by constituting the device so that an operation mode is switched to an automatic density adjusting mode in case a manual density adjusting means is set up on a prescribed position. CONSTITUTION:A density knob 10 is arranged on the operation panel of the copying device, image density can be increased by sliding the knob 10 downward, and if the knob 10 is downed until the lowest end, the density adjusting mode is switched from the manual mode to the automatic mode and an automatic density adjusting mode lamp 11 is turned on. In case the required density is set up by the knob 10, voltage extracted from a slide volume 4 is inputted to a terminal A of a CPU 1 and the voltage value is A/D converted by the CPU 1. The digital value after the A/D conversion is compared with a set value, and in case both the values coincide with each other, the lamp 11 is turned on, and then the density adjusting mode is switched to the automatic mode. |
