JPS60247275A - Fixing device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To stabilize the conveyance of paper to be fixed and to prevent wrinkling of said paper by forming the top end of a chute which guides the paper between a fixing roller and a press roller so as to parallel approximately with the nip part apart at an adequate space therefrom. CONSTITUTION:The fixing roller 1 having internally a heat source is made into approximately a concaved surface in which both ends have successively increasing diameters from the central part. The press roller 2 which brings the paper 3 to be fixed into press contact with the roller 1 is formed peripherally of an elastic material and the axial line 2' of the roller 2 is inclined slightly in the plane direction relative to the axial line 1' of the roller 1. The roller 1 side end of the chute 4 which guides the paper 3 between the rollers 1, 2 is inclined to meet the inclination of the nip part 5 between the rollers 1 and 2 in the conveying direction of the paper 3 as a result of intersecting the axial lines 1', 2' of the rollers 1, 2. The roller 1 side end of the roller 1 is so formed as to parallel with the nip part 5 at a space D.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a fixing device for an electronic copying machine that prevents wrinkles from forming on paper.

2. Description of the Related Art Conventionally, a fixing device for an electronic copying machine is known which includes a fixing row 2 having a substantially drum-shaped shape and containing a heat source, and a pressure row 2 that presses a sheet of paper to be fixed onto the fixing row 2. Furthermore, as shown in Fig. 3, by inclining the axis d of the pressure roller C in advance with respect to the axis s of the fixing roller a, the surface pressure of the nip I between each roller a and c can be made uniform. Some methods have also been proposed to prevent the occurrence of uneven fixation. With such a fixing device.

Since the inlet height between each row 2α and C changes along the axis and in the d direction, 1For example, if the feeding direction of shoe)g is set at the inlet height on the Δ end side as shown in FIG. is first nipped between each row 2α and C from the A end side of each roller α, C, and then the B end side nip is transferred,
A time difference occurs in the nip.

Problem to be Solved by the Invention Due to this nip time difference, one end side of the paper f is
Although it is nipped between α and C, the other end of the sheet falls down from the chute and enters between the rollers a and c, causing wrinkles on the sheet f.

The present invention was made in order to improve the above-mentioned problems, and it is an object of the present invention to provide a fixing device for an electronic copying machine that enables fixing without causing wrinkles on paper.

Means and operation for solving the problem By forming the tip of the chute for guiding the paper to be fixed between the fixing roller and the pressure roller so as to be approximately parallel to the nip portion with an appropriate distance therebetween, A fixing device for electronic copying machines that ensures that the leading edge of the paper always enters the nip in a stable state.

Embodiment An embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, numeral 1 denotes a fixing roller incorporating a heat source, which has an approximately hourglass shape (not shown) with diameter gradually increasing from the middle portion to both ends. ing. Reference numeral 2 denotes a pressure roller that presses the paper 3 to be fixed onto the fixing roller 21, and one periphery thereof is made of an elastic material, and the axis of the pressure roller 2 is aligned with the axis 1' of the fixing roller 21. In contrast, it is slightly inclined in the plane direction. Reference numeral 4 denotes a chute for guiding the paper 3 to be fixed between the rollers 1 and 2, and the end of the chute 4 on the side of the fixing row 21 crosses the axes 1' and 2' of the rollers 1 and 2. Therefore, the nip portion 5 between each row 21.2 is inclined in accordance with the inclination as shown in FIG. 2 with respect to the conveyance direction of the paper 3. In other words, the nip 5 between the rollers 1 and 2 and the end of the chute 4 on the fixing roller 1 side are formed parallel to each other with a gap between them.

Effects of the Invention Since the present invention has been described in detail above, the leading edge of the paper 3 guided by the chute 4 and reaching between each row 21.2 is moved from the A end side of each roller 1, 2 to the nip portion 5. The paper 30 enters the rows 21 and 2 and is nipped between the rows 21 and 2, but at this time, the other end of the paper 30 in the width direction is also on the chute 4, so it does not hang down from the chute 4. As a result, the leading edge of the paper 3 always enters the nip 5 between the rows 21, 2(3) in a stable state, thereby making it possible to prevent wrinkles from forming on the paper 3. In addition, since the tip of the chute 4 is made to be approximately parallel to the slope of the nip between the rollers 1 and 2 with an appropriate spacing, even when using cardboard, etc., the gap between each row 21. It is also possible to eliminate problems such as paper jams occurring at the entrance or the trailing edge of the paper 3 flying up and causing image disturbances.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention. 2 is a plan view showing a conventional fixing device, and FIG. 4 is a plan view of the conventional fixing device. 1 is a fixing roller, 2 is a pressure roller, 3 is a sheet of paper, and 4 is a plan view of the conventional fixing device. Chute, 5 is the nip part. Applicant: Fuji Xerox Co., Ltd. Representative Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto (4) Figure 1

Claims (1)

[Claims] A substantially drum-shaped fixing roller 1 having a heat source inside. The fixing roller 1 is provided with a pressure roller 22 that presses the paper 3 to be fixed, and the axis 2' of the pressure roller 22 is slightly inclined with respect to the axis 1' of the fixing roller 21. In a device with almost uniform surface pressure, the tip of the chute 4 that guides the paper 3 to be fixed between the fixing roller 1 and the pressure roller 22 is placed approximately parallel to the nip portion 5 with an appropriate interval. A fixing device for an electronic copying machine formed to do so.