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AssigneeKonica Corporation
InventorsHajime Tanaka, Hidetoshi Katayanagi, Toshiki Hayami
Estimating the term…
A fixing device includes; a heat roller having a cylindrical core with a heating source provided inside, an elastic body lined around the core, and a mold releasing layer covering the surface of the elastic body, and a pressure roller in pressure contact with the heat roller. A toner image is fixed by sandwiching, heating and pressurizing of the transfer material where the unfixed toner image fed to the pressed nip of the two aforementioned rollers is transferred. The hardness of the pressure roller is set higher than that of the heat roller, and the reference in Asker C hardness is set from 10 to 15°.
A fixing device comprising;
Dependencies are inferred from the claim text.
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Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating: relating to the chemical composition of…
Stable handling of copy medium: decurling device
Electrography
Term end not estimated
The present invention relates to a fixing device and an electrophotographic image forming apparatus equipped with such a fixing device, wherein the fixing device protects fixing performance against possible deterioration caused by winding of a transfer material when toner is fixed on the transfer material.
According to the prior art, toner fused on the transfer material at the time of fixing sticks to a heat roller, and winding is caused by separation failure in some cases. To solve the problem, an oil coating device, for example, is provided so that good separability is ensured even in the case of a flat nip. However, the oil coating mechanism equipped with an oil roller and related parts contain many replacements parts that require replacement work on a periodic basis. The has resulted in troublesome handling and hence waste of time, with the result that printing cost per sheet has to be increased.
The object of the present invention is to solve such a problem and to provide a fixing device and an image forming apparatus equipped therewith, wherein the fixing device is characterized by stable fixing performances and reduced printing cost without transfer material being contaminated by oil, free from troublesome handling of an oil coating device or replacement of parts.
FIG. 1 is a cross sectional view of a fixing device and an image forming apparatus equipped therewith as an embodiment of the present invention;
FIG. 2 is a cross sectional view showing the configuration of a heat roller and pressure roller used in the fixing device according to the present invention; and
FIG. 3 is a cross sectional view representing the fixing device according to the present invention and a sheet curl correction device located downstream thereof.
The following describes the embodiment of the present invention. It should be noted that the following description is not intended to define the technical scope of the aforementioned structures or meanings of the related terminologies. The following fragmentary explanation of the embodiment according to the present invention is based on the best mode, without being restricted to the meaning of the terminologies or technical scope.
FIG. 1 is a cross sectional view of an fixing device and a color image forming apparatus as an image forming apparatus equipped therewith as an embodiment of the present invention.
The color image forming apparatus corresponds to what is called a tandem type color image forming apparatus. It is composed of plural sets of image forming units 10Y, 10M, 10C and 10K, an endless belt-shaped intermediate transfer unit, a paper feeding and conveying means 21 and a fixing device 24. A document image reader SC is mounted on the top of the main body A of the image forming apparatus.