Back to results
US 6,029,022 AGranted
Image forming apparatus
AssigneeMinolta Co., Ltd.
InventorMakoto Takase
Life of this patent
Estimating the term…
Abstract
The object of the present invention is to provide an image forming apparatus capable of producing excellent images without transfer irregularities regardless of impedance fluctuation dependent on transfer timing, and which avoids enlargement of the apparatus. The aforesaid objects are attained by the image forming apparatus of the present invention which sequentially transfers toner images formed by a plurality of image forming units onto the same transfer sheet via a plurality of transfer charging means, wherein transfer output is controlled in accordance with the change of impedance of the transfer area dependent on the timing of each transfer.
Claims24
An image forming apparatus comprising:
- a plurality of image forming units for forming a plurality of toner images;
- a transfer device for sequentially transferring said plurality of toner images onto the same transfer member via a predetermined transfer output in a plurality of transfer areas;
- a controller for controlling the transfer output of said transfer device in accordance with the change in impedance of a transfer area dependent on the timing of each transfer,
- a transfer member transporting device for transporting said transfer member sequentially past the transfer areas of said transfer device;
- and
- an impedance detection unit positioned upstream from the transfer area on the farthest upstream side of said transfer member in the direction of transport so as to control the transfer output of said transfer device via said controller in accordance with a detected impedance value.
3 more elements
An image forming apparatus comprising:
- a plurality of image forming units for forming a plurality of toner images;
- a transfer device for sequentially transferring said plurality of toner images onto the same transfer member via a predetermined transfer output in a plurality of transfer areas;
- and
- a controller for controlling the transfer output of said transfer device in accordance with the change in impedance of a transfer area dependent on the timing of each transfer,
- wherein the change in impedance of a transfer area dependent on the timing of each transfer is a rise in impedance when the trailing edge of said transfer member separates from an upstream transfer area.
2 more elements
An image forming apparatus comprising:
- a plurality of image forming units for forming a plurality of toner images;
- a transfer device for sequentially transferring said plurality of toner images onto the same transfer member via a predetermined transfer output in a plurality of transfer areas;
- and
- a controller for controlling the transfer output of said transfer device in accordance with the change in impedance of a transfer area dependent on the timing of each transfer,
- wherein the change in impedance of a transfer area dependent on the timing of each transfer is a drop in impedance when the leading edge of said transfer member enters a downstream transfer area.
2 more elements
An image forming apparatus comprising:
- a plurality of image forming units for forming a plurality of toner images;
- a transfer device for sequentially transferring said plurality of toner images onto the same transfer member via a predetermined transfer output in a plurality of transfer areas;
- and
- a controller for changing the transfer output in accordance with a previously prepared table stored in memory expressing the relationship between the change in impedance and transfer output.
1 more element
A method of forming an image, said method comprising the steps of:
- forming a plurality of toner images;
- sequentially transferring said plurality of toner images onto a same transfer member via a predetermined transfer output in a plurality of transfer areas;
- controlling the transfer output of a transfer device in accordance with the change in impedance of a transfer area dependent on the timing of each transfer,
- transporting said transfer member sequentially past the transfer areas of said transfer device;
- detecting an impedance value via an impedance detection unit positioned upstream from the transfer area on the farthest upstream side of said transfer member in the direction of transport;
- and
- controlling the transfer output of said transfer device via said controller in accordance with said detected impedance value.
4 more elements
A method of forming an image, said method comprising the steps of:
- forming a plurality of toner images;
- sequentially transferring said plurality of toner images onto a same transfer member via a predetermined transfer output in a plurality of transfer areas;
- and
- controlling the transfer output of a transfer device in accordance with the change in impedance of a transfer area dependent on the timing of each transfer,
- wherein the change in impedance of a transfer area dependent on the timing of each transfer is a rise in impedance when the trailing edge of said transfer member separates from an upstream transfer area.
2 more elements
A method of forming an image, said method comprising the steps of:
- forming a plurality of toner images;
- sequentially transferring said plurality of toner images onto a same transfer member via a predetermined transfer output in a plurality of transfer areas;
- and
- controlling the transfer output of a transfer device in accordance with the change in impedance of a transfer area dependent on the timing of each transfer,
- wherein the change in impedance of a transfer area dependent on the timing of each transfer is a drop in impedance when the leading edge of said transfer member enters a downstream transfer area.
2 more elements
A method of forming an image, said method comprising the steps of:
- forming a plurality of toner images;
- sequentially transferring said plurality of toner images onto a same transfer member via a predetermined transfer output in a plurality of transfer areas;
- and
- changing the transfer output in accordance with a previously prepared table stored in memory expressing a relationship between the change in impedance and transfer output.
1 more element
Dependencies are inferred from the claim text.