Patent ID: 8861991

Claim:
A development device comprising: a development housing; a first developer conveyance member disposed in the development housing to transport by rotation developer contained in the development housing; a developer bearer to carry by rotation the developer contained in the development housing to a development range facing a latent image bearer; and a developer amount detector to detect an amount of the developer contained in the development housing, the developer amount detector including, a light-emitting element, a light-receiving element, a first light guide including a first end into which light emitted from the light-emitting element enters, and a second end positioned inside the development housing and from which light in the first light guide exits, and a second light guide including a first end positioned inside the development housing facing the second end of the first light guide across a predetermined distance, and a second end from which light in the second light guide exits, wherein at least one of the second end of the first light guide and the first end of the second light guide is stationary, wherein the second end of the first light guide and the first end of the second light guide are arranged in an axial direction of the first developer conveyance member, forming a light transmission path therebetween, and wherein at least a part of the light transmission path is positioned inside a locus of rotation of the first developer conveyance member.