JPH01227178A - Fixing device for electrophotographic printer - Google Patents

Abstract

PURPOSE:To prevent sheets ejected from a fixing device from curling by inserting a printing sheet into two sets of heat rollers and pressure rollers reversely arranged and fixing an image. CONSTITUTION:One heat roller 1 is arranged on the front 6a of the printing sheet 6, while the other heat roller 3 is arranged on the back 6b thereof. The printing sheet 6 whereto toner attaches to the front 6a side initially passes through the heat roller 1 and the pressure roller 2 to fix toner, and curls in the direction shown by a symbol (a). Then, the sheet 6 advances along a sheet guide 5 and passes through the heat roller 3 and the pressure roller 4 arranged by reversing the positions of the heat roller 1 and the pressure roller 2 in the preceding stage. As a result, the sheet 6 curls in the direction shown by a symbol (b), which offsets the previous force in the direction of the symbol (a), and its curl is corrected. Ultimately the sheet is ejected horizontally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic printer, and more particularly to a fuser.

[Conventional technology]

Conventionally, this type of fixing device is composed of a pair of heat rollers and a pressure roller, and a sheet of paper carrying toner is passed between these two rollers, and the toner is fixed on the paper by the heat of the heat roller.

[Problem to be solved by the invention]

The conventional fuser described above has only one pair of heat rollers and pressure rollers, so heat is applied only to the heat roller side of the paper, which evaporates the moisture in the paper and causes the paper to curl toward the heat roller side. There is.

An object of the present invention is to provide a fixing device for an electrophotographic printer that solves the above problems.

[Means to solve the problem]

In order to achieve the above object, in the fixing device of the electrophotographic printer of the present invention, a pair of a heat roller that heats the printing paper and a pressure roller that presses the printing paper against the heat roller is provided along the conveyance path of the printing paper. One heat roller is disposed on the front side of the printing paper, and the other heat roller is disposed on the back side of the printing paper.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.

In the figure, the present invention includes a pair of heat rollers 1 and 3 that heat the printing paper 6 and pressure rollers 2 and 4 that press the paper 6 against the heat rollers 1 and 3 on the transport path of the printing paper 6.
The heat rollers 1 are placed on the front and rear sides of the paper guide 5 along the paper guide 5, and one heat roller 1 is placed on the front side 6a of the printing paper 6, and the other heat roller 3 is placed on the back side 6b of the printing paper 6. It is.

In the embodiment, the printing paper 6 with toner attached to the front surface 6a first passes between the heat roller 1 and the pressure roller 2, the toner is fixed, and the paper 6 curls in the direction a. Next, along the paper guide 5, press the heat roller 1 at the front stage.
By passing between the heat roller 3 and the pressure roller 4, which are arranged with the positional relationship reversed between the paper and the pressure roller 2, the paper curls in the b direction. 6, the curl is corrected and the paper is discharged horizontally.

[Effects of the Invention] As explained above, in the present invention, since printing paper is passed through two pairs of heat rollers and pressure rollers whose arrangement positions are reversed to perform fixing, curling of the paper discharged from the fixing device is prevented. There are preventable effects.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the fixing device of the present invention. 1.3...Heat roller 2,4...Pressure roller S...Paper guide 6...Printing paper patent applicant Niigata NEC Co., Ltd.

Claims (1)

[Claims] 1. In the fixing device of an electrophotographic printer, there are two pairs of a heat roller that heats the printing paper and a pressure roller that presses the printing paper against the heat roller along the printing paper conveyance path. A fixing device for an electrophotographic printer, characterized in that a roller is disposed on the front side of the printing paper, and the other heat roller is disposed on the back side of the printing paper.