US Patent 9063507 Development device, process cartridge, and image forming apparatus

A development device includes a developer storage chamber configured to store a developer, a developer carrying member configured to carry the developer, a light transmission member capable of transmitting detection light for detecting a remaining amount of a developer in the developer storage chamber, a shaft member which is provided to the developer storage chamber and configured to rotate, a conveyance unit which is provided to the shaft member and configured to convey the developer, and a cleaning unit which is provided to the shaft member and configured to rub and clean the light transmission member, wherein the shaft member includes an opening.