| 摘要 |
PROBLEM TO BE SOLVED: To surely detect whether toner remains in a toner housing part or not. SOLUTION: A signal obtained by a photodiode 64 following up pulse emitted light emitted from an LED 62 based on a light emission timing signal(LEDON) is integrated by an integrator 71 and further a sampling signal(SAMTRIG) is generated in timing for sampling a SENOUT signal obtained by comparing the integration signal with a specified threshold light quantity level signal in a comparator 72 when the signal is outputted in a state where the signal level is stable. Whether the toner remains or not is decided by using a count signal(SCOUNT) obtained as the result of sampling. |
