| 摘要 |
PURPOSE:To supplying such a device for detecting toner quantity in a toner box that a developing unit can be easily replaced by making the part of the toner box light transmissiable and providing a photosensor in the face of the light transmissiable part. CONSTITUTION:A developing unit housing 1 is removable from a copying machine main body along a guide 10, and the toner box 4 consists of a light transmissivity material and is constituted so that the toner does not adhere to it by mirror-finishing its inner wall surface, etc. The photosensor is constituted by providing a light emitting unit 14 in the face of a first bracket 12 fixed to the frame 11 of the copying machine main body, and a light receiving unit 15 in the face of a second bracket 13. Thus, the toner quantity in the toner box 4 can be detected based on the output of the photosensor. Moreover, since the photosensor is provided independently from the toner box 4, the photosensor can be reused when the developing unit is replaced to a new one, therefore, cost can be reduced. |
