| 摘要 |
PURPOSE:To prevent toner from scattering from a supply opening in the development unit main body and a toner cartridge opening when toner in the toner cartridge runs out and the cartridge is detached from the development unit main body. CONSTITUTION:A development chamber 32 demarcated by a movable plate 41 and a sheet attached to the plate is formed in the development unit main body 30. The movable plate 41 is turnably supported by being provided with a support shaft 42 integrally at its lower end. A gear 45 is attached to the support shaft. On the other hand, on the opening 56 of the toner cartridge 31 a shutter 58 which covers and uncovers the opening 56 by turning 90 deg. is provided, and a segment gear 59 is provided on the shaft of the shutter 58. The segment gear 59 and the gear 45, both of which engage, and the movable plate 41 compose a development chamber extension mechanism 40. When the shutter 58 is closed, the development chamber extension mechanism 40 is driven in response to the rotation or the shutter 58, thereby extending the development chamber 32 and increasing capacity for containing toner. |
