Developing device, and image forming apparatus and process unit incorporating same

摘要

A developing device includes a developer container, a developer bearer, a partition to divide an interior of the developer container into a first compartment to which developer is supplied and a second compartment in which the developer bearer is disposed, main communication openings provided at both ends of the partition, a sub-communication opening provided in an intermediate portion of the partition, developer conveyance members provided in the first compartment and the second compartment to circulate developer between the first compartment and the second compartment, and a developer amount detector to detect an amount of developer in a detection area positioned in the first compartment and adjacent to the sub-communication opening.

主权项

1. A developing device comprising:
a developer container to contain developer; a developer bearer to bear developer on a surface thereof; a partition to divide an interior of the developer container into a first compartment to which developer is supplied and a second compartment in which the developer bearer is disposed; main communication openings provided at both ends of the partition, the main communication openings through which the first compartment and the second compartment communicate with each other; a sub-communication opening provided in an intermediate portion of the partition, the sub-communication opening through which the first compartment and the second compartment communicate with each other; developer conveyance members respectively provided in the first compartment and the second compartment to circulate by rotation developer therebetween; and a developer amount detector to detect an amount of developer in a detection area positioned in the first compartment, the detection area adjacent to the sub-communication opening, wherein the developer amount detector includes:
a light-emitting element to emit light;a light-receiving element to receive the light;a first light guide including an end face disposed inside the first compartment to guide the light emitted from the light-emitting element into the first compartment; anda second light guide to guide the light guided to the first compartment to the light-receiving element, the second light guide including an end face disposed inside the first compartment across a light transmission path from the end face of the first light guide.