Developing device having toner agitation member and cleaning member cleaning light transmission

摘要

A developing unit (50) having a toner container (51) in which a toner agitator (53) and a cleaning member (54) is provided. The toner agitator (53) agitates the toner in the toner container (51) and transport the toner into a developing chamber (57). The toner container (51) has a pair of light transmission windows (56a,56b) through which light passes. If no toner exists between the light transmission windows (56a,56b), the light passes through to provide a signal indicative of exchange of the developing device unit (50). If toner exists therebetween, light cannot pass through two windows. The cleaning member (54) wipes off the toner from the surface of the windows. A blade shaped light blocking member (80) is provided between the support member (53a) of the agitator (53) and the support member (54a) of the cleaning member (54). The light blocking member (80) is formed from resin. The light blocking member (80) is formed integrally with the agitator (53), the cleaning member (54), and the rotational shaft (55) so as to rotate around the axial center of the rotational shaft (55) with rotation of the rotational shaft (55).