Electrophotography – Image formation – Development
Reexamination Certificate
2000-02-18
2001-12-25
Grainger, Quana M. (Department: 2852)
Electrophotography
Image formation
Development
C399S260000
Reexamination Certificate
active
06334037
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus and, more particularly, to an improvement in the developer replenishment mechanism of the image forming apparatus.
An image forming apparatus for forming an electrostatic latent image on an image carrier, developing the image with toner in a developing unit, and transferring the toner image onto a sheet, comprises a container (toner cartridge or toner bottle) for replenishing the developing unit with toner. This toner cartridge has a spiral on its inner surface. When the toner cartridge itself rotates, the contained toner is squeezed out from an outlet port along the spiral and supplied to the developing unit.
The outlet port of the toner cartridge is open in mounting a new toner cartridge on the apparatus main body or dismounting an empty toner cartridge from the apparatus main body. For this reason, toner escapes from the outlet port and scatters in the apparatus to contaminate the apparatus.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a developer cartridge which prevents a developer from escaping from a outlet port and scattering in an apparatus in mounting/dismounting on/from the apparatus main body.
It is another object of the present invention to provide an image forming apparatus having the developer cartridge which prevents a developer from escaping from the outlet port and scattering in the apparatus in mounting/dismounting on/from the apparatus main body.
According to the present invention, there is provided a developer cartridge which is rotatably mounted in a developing unit of an image forming apparatus, and supplies a developer to the developing unit while rotating, comprising a cylindrical cartridge main body having a developer outlet hole in an outer surface near one end, and a ring-like cartridge-side shutter which is fitted on the outer surface near one end of the cylindrical cartridge main body to be movable along a rotating shaft of the cylindrical cartridge main body between a position where the developer outlet hole is opened and a position where the developer outlet hole is closed, wherein the developing unit has a guide for inserting the developer cartridge and a driving unit for rotating the developer cartridge, the guide has a main body-side shutter with a hole, and when the developer cartridge is mounted, the cartridge-side shutter of the cylindrical cartridge main body moves from the position where the developer outlet hole is closed to the position where the developer outlet hole is opened, the developer outlet hole aligns itself with the hole of the main body-side shutter, and every time the cylindrical cartridge main body and the main body-side shutter integrally rotate to align the developer outlet hole and the hole of the main body-side shutter with a developer replenishment port formed below the main body-side shutter, the developer in the developer cartridge is supplied from the developer replenishment port to the developing unit via the developer outlet hole and the hole of the main body-side shutter.
According to the present invention, there is provided an image forming apparatus comprising a developing unit for developing an electrostatic latent image on an image carrier with a developer, and a transfer unit for transferring the developed developer image onto a transfer medium, wherein the developing unit has a developer cartridge rotatably mounted to supply the developer to the developing unit while rotating, a guide for inserting the developer cartridge, and a driving unit for rotating the developer cartridge; the developer cartridge has a cylindrical cartridge main body having a developer outlet hole in an outer surface near one end, and a ring-like cartridge-side shutter which is fitted on the outer surface near one end of the cylindrical cartridge main body to be movable along a rotating shaft of the cylindrical cartridge main body between a position where the developer outlet hole is opened and a position where the developer outlet hole is closed; the guide has a main body-side shutter with a hole; and when the developer cartridge is mounted, the cartridge-side shutter of the cylindrical cartridge main body moves from the position where the developer outlet hole is closed to the position where the developer outlet hole is opened, the developer outlet hole aligns itself with the hole of the main body-side shutter, and every time the cylindrical cartridge main body and the main body-side shutter integrally rotate to align the developer outlet hole and the hole of the main body-side shutter with a developer replenishment port formed below the main body-side shutter, the developer in the developer cartridge is supplied from the developer replenishment port to the developing unit via the developer outlet hole and the hole of the main body-side shutter.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumetalities and combinations particularly pointed out hereinafter.
REFERENCES:
patent: 5475469 (1995-12-01), Okada et al.
patent: 5774773 (1998-06-01), Otsuka et al.
Foley & Lardner
Grainger Quana M.
Toshiba Tec Kabushiki Kaisha
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