Patent ID: 7555230
Filing Date: 2009-06-30
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a plurality of development apparatuses each for one of a plurality of colors to develop electrostatic images formed on an image retaining member; a developer supply means for supplying toner of each color to the respective development apparatus, the toner of the respective color being supplied to each of the development apparatuses in accordance with the amount of toner in each of the development apparatuses; a sensor device including a light emitting member and a light receiving member which outputs upon receiving light a detection signal in accordance with the intensity of the received light; a pattern forming means provided in each of the development apparatuses for forming a light pattern with the light emitted from said light emitting member, which light pattern is different for each of said development apparatuses when a concerned one among said development apparatuses is brought to a developing position in the image forming apparatus; and a control means which discerns said concerned development apparatus brought to the developing position and at the same time determines an amount of developer existing in said concerned development apparatus based on the detection signal generated from the light received in the light pattern associated with said concerned development apparatus, and which controls said developer supply means based on said determination to control supply of developer to said concerned development apparatus.