摘要 |
An image forming apparatus includes an image bearing member, an electrostatic image forming device for forming an electrostatic image based on an image signal on the image bearing member, a developing device for developing the electrostatic image on the image bearing member, a detector for detecting the amount of a toner in the developing device, an integrating device for integrating a number of image signals produced by the apparatus, and an estimator for estimating and indicating whether the apparatus has consumed a predetermined amount of toner, on the basis of the integrated amount integrated by the integrating device before the detector detects the consumption of all the toner. |