DETECT LIGHT REFLECTED FROM A DEVELOPER MEMBER OF A TONER CARTRIDGE

摘要

An image forming apparatus includes a toner cartridge, a light source, a light guiding device, and an optical sensor. The toner cartridge includes a developer member and a photosensitive member. The developer member receives toner and applies the toner to the photosensitive member. The light source emits light. The light guiding device guides the light from the light source at a plurality of areas on the developer member. The optical sensor detects an amount of reflected light reflected from the developer member.