| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect the density of toner even when a period to count the number of pulses is set short.SOLUTION: An LC resonance circuit 110 comprises a detection coil and capacitor, and outputs a pulse signal having a frequency according to the density of toner. A multiplication part 120 multiplies the frequency of the pulse signal output from the LC resonance circuit 110. A density detection part 150 detects the density of toner on the basis of the number of pulses of the pulse signal multiplied by the multiplication part 120 for each of periods to sample the number of pulses.SELECTED DRAWING: Figure 1 |
