Fuji Xerox Co., Ltd.

Shintaro Kaneko

Ryuji Hattori

Shigemi Murata

Tetsuji Okamoto

Hirohisa Kohno

Hiroo Nishide

An image forming apparatus has a latent image writing device that writes an electrostatic latent image on an image bearing member, a developing device that develops a toner image based on the electrostatic latent image, a transferring device that transfers the toner image onto a recording material, a position correcting unit that corrects a position of the electrostatic latent image written by the latent image writing device, a recording material determining unit that determines whether or not the recording material has a long width, and a corrected amount changing unit that, when the recording material determining unit determines that the recording material has a long width, changes an amount of correcting the position of the electrostatic latent image to a value different from a set value for a recording material having a standard width.

Image forming apparatus

A developing apparatus has a developer support 2 to which a developing bias VB with an AC component VAC superimposed on a DC component is applied for visualizing a latent image on a latent image support 1 in a dual component developer G supported on the developer support 2. It includes a use history estimation 5 for estimating a use history of the developer G or a use history detection device 6 for detecting a use history of the developer G and a developing bias power supply 3 provided with a peak-to-peak voltage changing device 4 for changing a peak-to-peak voltage Vp-p of the AC component VAC based on information from the use history estimation device 5 or the use history detection means 6.

Developing apparatus

A rotary-type developing unit includes: a rotary holder mounting a plurality of developing devices; each of the developing devices having: a developing housing storing a two-component developer consisting of a toner and a carrier and including a developing opening formed in part thereof; a developer carrier disposed opposed to the developing opening of the developing housing and carrying the two-component developer thereon; and a developer delivery member stirring and delivering the developer existing within the developing housing so as to supply the developer to the developer carrier. The developer carriers of the respective developing devices are selectively arranged at a developing position facing a latent image carrier by rotating the rotary holder intermittently, whereby respective color component latent images on the latent image carrier are respectively developed by the respective corresponding developing devices. A developer storing recessed portion where a developer free from the operation of the developer delivery member is stored is formed downwardly of the developer delivery member of the developer housing, in a state in which each of the developing devices is set at the developing position.

Rotary-type developing unit

In an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer, for performing development by using a two-component developer, a carrier collecting device for collecting a carrier deposited on a photosensitive member in development is provided. The carrier collecting device includes a fixed magnet disposed in such a manner that an intermediate position between an S pole and an N pole of the fixed magnet is closest to the photosensitive member. Accordingly, the carrier can be effectively collected from the photosensitive member, and the carrier captured to the fixed magnet can be prevented from rubbing against the photosensitive member.

Apparatus for collecting developer carrier in a electrophotographic

A method of making a reproduction copy of an image or a document by electrophotography wherein high print density portions of an original image are developed and transferred onto a recording medium before low print density portions of the original image are developed and transferred onto the recording medium. The original image is multiply scanned under successive, controlled conditions to produce a series of latent images, each of which represents a print density component of the original image. Each latent image is developed and transferred onto the recording medium to produce a composite print density and gradation which closely approaches the print density and gradation of the original document or a predetermined density and gradation.

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Ebina, Japan

Shintaro Kaneko