Image forming device and image forming method

Abstract

The invention relates to a method and apparatus for forming image on two side of a recording medium that is capable of forming an appropriate image even on a special transfer sheet, such as a thick paper or an envelope. The transfer current applied to a first transfer means 21 and a second transfer means 22 is increased by 10-30% from that at the time of using ordinary paper, and also the temperature of fixing rollers 18 and 19 is raised by 10-30% from that at the time of using the ordinary paper. In the case of feeding longer paper than the circumferential length of an intermediate transfer belt 10 from a roll paper feeding device 300, the transfer of a toner image to the intermediate transfer belt 10 is inhibited. Also, in the case of the long-sized paper, the temperature of the fixing rollers 18 and 19 is raised by 10-30% from that at the time of ordinary paper. This invention can prevent defects of tranfer printing and fixation and improve the quality of the image even in case of using the thick paper, envelope, longer paper and special paper.

Description

[0001] This application is a divisional application of the invention patent application with the application number 01137194.3, the application date is October 24, 2001, the applicant is Ricoh Co., Ltd., and the invention title is "image forming method and device thereof". technical field [0002] The present invention relates to a method and apparatus for forming images on both sides of a recording medium. Background technique [0003] Some image forming apparatuses such as copiers, printers, and facsimiles can form images on both sides of a recording medium (hereinafter simply referred to as “paper” for simplicity). In the conventional image forming apparatus capable of double-sided recording, the following method is generally used: the image (developed image) formed on one side of the image carrier is transferred to paper, fixed, and then the paper is turned over by a reversing passage or the like. , the paper is fed again, and the ...

AI Technical Summary

Problems solved by technology

[0011] However, in the above devices, it is sometimes necessary to use special paper

[0012] For example, in the case of special paper such as thick paper, if the image is formed as in the case of normal paper, it is difficult for the paper to pass through the conveying path, and paper bending, paper jams, or problems in image density or fixability may occur. Problems such as low image quality

For this problem, the devices described in the above-mentioned publications have not considered

[0013] In addition, when the intermediate transfer belt is used as the second image carrier and can be recorded on both sides, when special paper such as long recording paper is used, there is a problem of how to deal with long image data exceeding the circumference of the intermediate transfer belt.

[0014] In addition, when fixing long paper as special paper, there are problems such as lowering of the fixing temperature, correspondence between the paper feed unit and the paper discharge unit for long paper, and the simplification of the method of making the recording paper long paper into the information input device.

For the above-mentioned problem, the devices described in the above-mentioned publications do not involve

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