US RE38,164 E1Granted

Desktop color copier which includes a revolving type developing device

AssigneeRicoh Company, Ltd.

InventorsSusumu Wagi, Kyoji Omi

Life of this patent

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Abstract

A desktop color copier having a size which allows the copier to be placed on a stand when the copier is used. The desktop color copier includes a photoconductive drum for sequentially forming toner images of respective colors thereon, a charger for charging the photoconductive drum, an exposure device for exposing the charged photoconductive drum, a revolving type developing device for forming color toner images on the photoconductive drum, an image transferring devices which includes an intermediate transfer belt to which the color toner images are sequentially transferred one on top of the other, and a fixing device for fixing the color toner images on a sheet of paper. The desktop color copier includes a single paper feed tray which is located under the transferring device.

Claims53

Dependent claims

A color image forming apparatus for forming a toner image on a sheet of paper, comprising:

an image carrier for substantially forming toner images of respective colors thereon;
a charger for charging said image carrier;
an exposure device for exposing said image carrier which has been charged and forming electrostatic latent images of respective colors on said image carrier;
a revolving type developing device which is rotatively supported in said color image forming apparatus, including a plurality of color developing devices, each of which includes a developing unit for developing a toner image on said image carrier when said developing unit faces said image carrier and a toner supply unit for supplying toner to said developing unit, wherein an external shape of said revolving type developing device is a cylinder;
an intermediate transfer belt to which said toner images are sequentially transferred on top of previously transferred toner images;
a primary transferring charger for sequentially transferring said toner images from said image carrier to said intermediate transfer belt to form a composite toner image on said intermediate transfer belt;
at least one paper feed tray for storing sheets of paper and feeding the sheets of paper one at a time;
a secondary image transferring charger for transferring said composite toner image from said intermediate transfer belt to one of the sheets of paper;
and
a fixing device for fixing said toner image on said sheet of paper,
wherein a length of said intermediate transfer belt is greater than a circumference of said image carrier.

8 more elements

A color image forming apparatus for forming a toner image on a sheet of paper, comprising:

an image carrier for sequentially forming toner images of respective colors thereon;
a charger for charging said image carrier;
an exposure device for exposing said image carrier which has been charged and forming electrostic latent images of respective colors on said image carrier;
a revolving type developing device which is rotatively supported in said color image forming apparatus, including a plurality of color developing devices, each of which includes a developing unit for developing a developing a toner image on said image carrier when said developing unit faces said image carrier;
intermediate transfer belt to which said toner images are sequentially transferred on top of previously transferred toner images;
primary transferring charger for sequentially transferring said toner images from said image carrier to said intermediate transfer belt to form a composite toner image on said intermediate transfer belt;
at least one paper feed tray for storing sheets of paper and feeding the sheets of paper one at a time;
a secondary image transferring charger for transferring said composite toner image from said intermediate transfer belt to one of the sheets of paper;
and
a fixing device for fixing said toner image on said sheet of paper,
wherein a length of said intermediate transfer belt is greater than a circumference of said image carrier.

8 more elements

A color image forming apparatus for forming a toner image on a sheet of paper, comprising:

an image carrier for sequentially forming toner images of respective colors thereon;
a charger which is proximate to said image carrier;
an exposure device for exposing said image carrier which has been charged and forming electrostatic latent images of respective colors on said image carrier;
a revolving type developing device which is rotatively supported in said color image forming apparatus such that a locus of the rotation of said revolving type developing device is overlapped with a locus of the rotation of said image carrier, said revolving type developing device including a plurality of color developing devices, each of which includes a developing unit for developing a toner image on said image carrier when said developing unit faces said image carrier;
an intermediate transfer medium which is disposed proximate to said image carrier such that said toner images are sequentially transferred on top of a previously transferred toner image on said intermediate transfer medium;
at least one paper feed tray for storing sheets of paper;
rollers which feed the sheets of paper one at a time from said at least one paper feed tray to said intermediate transfer medium from which said toner images are transferred to said sheets of paper;
and
a fixing device for fixing said toner images on said sheets of paper,
wherein a length of said intermediate transfer medium is greater than a circumference of said image carrier.

7 more elements

A color image forming apparatus for forming a toner image on a sheet of paper, comprising:

an image carrier for sequentially forming toner images of respective colors thereon:
a charger which is proximate to said image carrier;
an exposure device for exposing said image carrier which has been charged and forming electrostatic latent images of respective colors on said image carrier;
a revolving type developing device which is rotatively supported in said color image forming apparatus including a plurality of color developing devices, each of which includes a developing unit for developing a toner image on said image carrier when said developing unit faces said image carrier;
an intermediate transfer belt which is disposed proximate to said image carrier such that said toner images are sequentially transferred on top of a previously transferred toner image on said intermediate transfer belt;
at least one paper feed tray for storing sheets of paper;
rollers which feed the sheets of paper one at a time from said at least one paper feed tray to said intermediate transfer belt from which said toner images are transferred to said sheets of paper;
and
a fixing device for fixing said toner images on said sheets of paper,
wherein a length of said intermediate transfer belt is greater than a circumference of said image carrier.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/851,088Filed 9 May 2001 · reissue
Priority: JP 5-08935123 Mar 1993
Granted: 1 Jul 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification0 codes

Family

Application08/215,608Parent of this continuation-in-part · filed 22 Mar 1994
Application08/581,922Parent of this continuation · filed 2 Jan 1996
Application09/040,458Reissue · filed 18 Mar 1998
US 6,049,396 AReissue · filed 11 Apr 2000
Application09/040,458Parent of this continuation
US 5,838,456 AParent of this continuation
Application08/581,922Parent of this continuation-in-part
US 5,600,445 AParent of this continuation-in-part
US RE38,164 E1This patent

From the US filing history. Foreign family members aren’t listed.