| 摘要 |
PURPOSE:To detect the deterioration of a developer, by comparing the output from an optical sensor which detects the density of a toner with a reference level with the 1st and the 2nd comparators. CONSTITUTION:A comparator 11 compares the output voltage V1 from an optical element and a slice level SL1, outputs a compared output signal A and inputs the same to a timer 12. The timer 12 delays the input signal by a timer T1, outputs a strobe signal B having the width of a time T2 and inputs the same to an AND element 14. On the other hand, a comparator 13 to which the output voltage V1 is inputted compares V1 and a slice level SL2, outputs a compared output signal C and inputs the same to the element 14. The element 14 inputted with the signal B and the signal C outputs an AND Vout and detects the deterioration of the developer. |
