| 摘要 |
PURPOSE: To precisely control a toner concentration without considering a mechanical and electrical change, even in the irregular fluctuation of an analog signal detected by a toner concentration sensor and the toner concn. with a simple change even in a change in design. CONSTITUTION: This toner concentration controller is provided with a comparator 52 comparing an analog signal for showing the state of a toner quantity detected by the toner concentration sensor 10 with the reference signal of a constant voltage, and converting into a rectangular wave signal, a pulse width detecting means 53 detecting the pulse width of the converted rectangular wave signal, and an arithmetic processing part 55 using plural bits of information of the pulse width detected by the pulse width detecting means 53, to calculate an operation value with an operation for averaging, difference and addition, and constituted to control the supplying of the toner based on the operation value processed by the arithmetic processing part 55. |
