JPS6217777A - Fixing device - Google Patents

Abstract

PURPOSE:To reduce the curling and wrinkling of paper and to improve fixing effect by providing a heating roller and a pressure roller which is in pressure contact with the heating roller and driven by the roller, and forming plural projected parts on the surface of either the heating roller or the pressure roller. CONSTITUTION:Plural convex stripes less than 0.3mm are provided on the surface of either a heating roller 1 or a pressure roller 2. When a sheet of paper 3 passes between the roller 1 and the roller 2 which is in pressure contact at specified pressure, the curling of the paper which is apt to occur between the convex stripes 4 and flat parts due to thermal effect is remarkably reduced by a physical correcting action that acts to smooth out by the convex stripes. Thus, a picture high in fixing effect can be obtained to reduce the curling and wrinkling of the paper.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to office equipment, particularly to fixing devices for copying machines, laser beam printers, and the like.

2. Description of the Related Art In recent years, the quality of images produced by copying machines and the like has improved significantly, and there is a need for more severe improvements in paper wrinkles, paper curls, and the like.

A conventional fixing device will be described below with reference to the drawings.

FIG. 5 is a front view of a conventional fixing device. In the figure,
1 is a heat roller, 2 is a rubber roller, and 3 is paper.

In the fixing device configured as described above, the paper 3 is fixed by passing between a heating roller and a pressure roller 2 that is pressed against the heating roller at a predetermined pressure while advancing in a direction perpendicular to the plane of the paper.

Problems to be Solved by the Invention However, with the above configuration, even if the temperature control of the heating roller is thermally devised, no physical countermeasures are taken, so paper curling and paper curling may occur. There was a problem in that paper wrinkles occurred during double-sided copying.

In view of the above-mentioned problems, the present invention provides a fixing device with good fixing properties without paper curl or paper wrinkles.

Means for Solving the Problems In order to solve the above problems, the present invention includes a configuration in which a plurality of protrusions of 0.31JI or less are provided on the surface of either the heating roller or the pressure roller. It is something that

Effects According to the present invention, with the above-described configuration, the paper is fixed while being straightened into a flat shape during fixing, so that the occurrence of paper curls and paper wrinkles is significantly reduced.

EXAMPLE Hereinafter, a heating roller according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an enlarged front view of essential parts of a fixing device according to a first embodiment of the present invention. In the figure, 1 is a heating roller coated with Teflon and has a built-in heat source, 2 is a pressure roller made of silicone rubber or the like, 3 is paper, and 4 is a plurality of protrusions.

The operation of the above configuration will be explained.

When the paper 3 passes between the heating roller 1 and the pressure roller 22 that is pressed against the heating roller 1 with a predetermined pressure, the paper 3 tends to curl between the ridges 4 of the heating roller 1 and the flat surface due to thermal factors. Even so, the curling is significantly reduced due to the physical correction effect of the protruding strips 4 to make them flat. Here, the reason why the protruding stripe is Q and 3mCB or less is because this protruding stripe is 0
．． This is because if it exceeds 38, the physical correction will be too large, especially for thin paper, and the paper will be deformed, or the thermal efficiency will deteriorate for thick paper, making it impossible to obtain the desired fixing quality.

As described above, according to this embodiment, paper curl and paper wrinkles can be significantly reduced by providing a plurality of protrusions of 0.3 m or less on the surface of either the heating roller or the pressure roller. .

In this first embodiment, the cross-sectional shape of the protruding strip of the heating row 21 is rectangular, but it may be an arc as shown in FIG. 2, or triangular as shown in FIG. 3. A similar effect can be obtained by using a trapezoid as shown in FIG.

Further, in this embodiment, although the heating roller is provided with a protruding strip, it goes without saying that similar effects can be obtained even if the protruding strip is provided on the pressure roller 2.

Effects of the Invention As described above, the present invention significantly reduces paper curl and paper wrinkles by providing a plurality of protrusions of 0.3111 or less on the surface of either the heating roller or the pressure roller, and improves fixing properties. Good images can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an enlarged front view of main parts of a fixing device according to a first embodiment of the present invention, FIG. 2 is an enlarged front view of main parts showing a second embodiment of the invention, and FIG. 3 is a third embodiment of the same. Enlarged front view of main parts showing
FIG. 4 is an enlarged front view of main parts showing the fourth embodiment, and FIG. 6 is a front view of a conventional fixing device. 1... Heat roller, 2... Pressure roller, 3... Paper, 4... Convex strip. Figure 1 Figure '4 ゝI

Claims (5)

[Claims] (1) It is characterized by comprising a heating roller and a pressure roller driven by the heating roller in pressure contact with the heating roller, and a plurality of protrusions are formed on the surface of either the heating roller or the pressure roller. Fixing device. (2) The fixing device according to claim 1, wherein the cross-sectional shape of the protruding stripes is arc-shaped. (3) The fixing device according to claim 1, wherein the protruding stripe has a triangular cross-sectional shape. (4) The fixing device according to claim 1, wherein the ridge has a trapezoidal cross-sectional shape. (5) The fixing device according to claim 1, wherein the height of the protruding strip does not exceed 0.3 mm.