Patent ID: 8295717
Filing Date: 2012-10-23
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image carrier; a toner-image forming unit configured to form a toner image on the image carrier with toner; a photosensor that is configured to detect a toner area where the toner is sticking to the image carrier form the toner image; an information obtaining unit that obtains particle-size-change information about how particle size distribution of the toner changes over time; a toner-amount calculating unit that calculates a toner amount based on the toner area and the particle-size-change information, the toner amount being an amount of the toner sticking to the image carrier to form the toner image, and a process cartridge detachably attached to a main body of the image forming apparatus, the process cartridge including at least a developing unit of the toner-image forming unit, wherein the information obtaining unit obtains the particle-size-change information based on a toner consumption ratio that is a ratio of an accumulative toner consumption over periods of time in which the process cartridge has been used to an amount of toner initially filled in the process cartridge.