US 2014/0270819 A1Published application

Image forming apparatus

AssigneeRicoh Company, Ltd.

InventorsYuuji WADA, Atsushi NAGATA

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Abstract

An image forming apparatus includes a primary transfer bias adjuster to adjust, in a second mode, a primary transfer bias by a correction amount in accordance with a degree of deterioration of a developing agent detected by a first developing agent condition detector so as to reduce a primary transfer current of the primary transfer bias upon transferring a toner image from a first image bearing member onto an intermediate transfer member, and to adjust, in a first mode, the primary transfer bias by a correction amount less than the correction amount in the second mode or not to adjust the primary transfer bias in accordance with the degree of deterioration of the developing agent detected by the first developing agent condition detector upon primarily transferring the toner image from the first image bearing member onto the intermediate transfer member.

Claims20

Dependent claims

An image forming apparatus, comprising:

an intermediate transfer member to move in a first direction;
a plurality of image bearing members to bear toner images thereon, the plurality of image bearing members disposed along the first direction;
a plurality of toner image forming devices to form the toner images on the plurality of image bearing members using different developing agents;
a primary transfer device to apply a primary transfer bias to primarily transfer each of the toner images formed on the plurality of image bearing members onto a surface of the intermediate transfer member to form a composite toner image;
a secondary transfer device to apply a secondary transfer bias to secondarily transfer the composite toner image formed on the intermediate transfer member to a recording medium;
a controller to selectively control image forming operation between a first mode and a second mode such that in the first mode the composite toner image is formed using at least two of the plurality of image bearing members including a first image bearing member and a second image bearing member and after the composite toner image is formed on the intermediate transfer member the secondary transfer bias is applied to secondarily transfer the composite toner image from the intermediate transfer member to the recording medium, and in the second mode the toner image is formed on the first image bearing member used in the first mode which is disposed downstream from the second image bearing member in the first direction and after the toner image is primarily transferred from the first image bearing member onto the intermediate transfer member the secondary transfer bias less than that in the first mode is applied to transfer the toner image from the intermediate transfer member to the recording medium;
a first developing agent condition detector to detect a degree of deterioration of a developing agent used to form the toner image on the first image bearing member;
and
a primary transfer bias adjuster to adjust, in the second mode, the primary transfer bias by a correction amount in accordance with the degree of deterioration of the developing agent detected by the first developing agent condition detector so as to reduce a primary transfer current of the primary transfer bias upon transferring the toner image from the first image bearing member onto the intermediate transfer member, and to adjust, in the first mode, the primary transfer bias by a correction amount less than the correction amount in the second mode or not to adjust the primary transfer bias in accordance with the degree of deterioration of the developing agent detected by the first developing agent condition detector upon primarily transferring the toner image from the first image bearing member onto the intermediate transfer member.

6 more elements

An image forming apparatus, comprising:

an image bearing member to rotate;
an intermediate transfer member to move in a first direction;
a plurality of toner image forming devices to form sequentially and overlappingly a plurality of toner images using different developing agents on a surface of the image bearing member to form a composite toner image;
a primary transfer device to apply a primary transfer bias to primarily transfer the composite toner image formed on the image bearing member onto a surface of the intermediate transfer member;
a secondary transfer device to apply a secondary transfer bias to secondarily transfer the composite toner image having been primarily transferred on the intermediate transfer member onto a recording medium;
a controller to selectively control image forming operation between a first mode and a second mode such that in the first mode the composite toner image is formed using at least two of the plurality of toner image forming devices including a first toner image forming device and a second toner image forming device and after the composite toner image is primarily transferred onto the intermediate transfer member the secondary transfer bias is applied to secondarily transfer the composite toner image from the intermediate transfer member onto the recording medium, and in the second mode the first toner image forming device used in the first mode forms the toner image which is transferred after the toner image formed by the toner image forming device other than the first toner image forming device is transferred and after the toner image formed by the first toner image forming device is primarily transferred onto the intermediate transfer member the secondary transfer bias less than that in the first mode is applied to transfer the toner image from the intermediate transfer member onto the recording medium;
a developing agent condition detector to detect a degree of deterioration of a developing agent used to form the toner image on the first toner image forming device;
and
a primary transfer bias adjuster to adjust the primary transfer bias by a correction amount in accordance with the degree of deterioration of the developing agent detected by the developing agent condition detector so as to reduce a primary transfer current of the primary transfer bias upon transferring the toner image formed by the first toner image forming device in the second mode, and to adjust the primary transfer bias by the correction amount less than the correction amount in the second mode or not to adjust the primary transfer bias in accordance with the degree of deterioration of the developing agent detected by the developing agent condition detector upon primarily transferring the toner image formed by the first toner image forming member in the first mode.

6 more elements

An image forming apparatus, comprising:

a plurality of image bearing members to rotate in a first direction;
a plurality of toner image forming devices to form a toner image on a surface of each of the plurality of image bearing members with developing agents including toners having different volume resistivities;
a plurality of transfer devices to apply a transfer bias to transfer the toner images formed on the plurality of image bearing members onto a transfer medium to form a composite toner image;
a developing agent condition detector to detect a degree of deterioration of the developing agents;
and
a transfer current adjuster to adjust a transfer current of the transfer bias by a correction amount in accordance with the degree of deterioration of the developing agent detected by the developing agent condition detector upon transferring the toner images formed on at least two image bearing members, the toner images being formed with the developing agents including the toners having different volume resistivities,
wherein the correction amount is different between the at least two image bearing members.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/209,330Filed 13 Mar 2014
Priority: JP 2013-05249614 Mar 2013
Published: 18 Sep 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G03G 15/553
Self-diagnostics; Malfunction or lifetime display: monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of…
G03G 15/0189
Using more than one reusable electrographic recording member, e.g. one for every monocolour image: primary transfer to an intermediate transfer belt
G03G 15/1605
Of a toner pattern, e.g. a powder pattern , e.g. magnetic transfer: using at least one intermediate support
G03G 15/556
Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job: for…