JPS6251554A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent paper from being crumpled and jammed and to prevent distrubance of an image by directing a chute body made of rigid material to a position lower than an inlet of a fixing roll, fixing an elastic material sheet to the forward end of the chute body, and bringing the forward end of the chute body into contact with a pressure roll at a position lower than the inlet. CONSTITUTION:A paper on which an unfixed image is placed is fed from a transport 5 toward a position lower than a rolling contact portion of a heat roll 2 with a pressure roll 3 by a chute body 7. Subsequently, the paper is fed in along an elastically deformable sheet 8, which is fixed to the forward end of the chute body 7 and brought into contact with the pressure roll 3 1 to 2mm apart from the rolling contact portion. Accordingly, the paper is kept flat until it enters the rolling contact portion, so that the paper is hardly crumpled, and if a paper is firm, the paper directly enters the rolling contact portion so that a jam hardly occurs. Though the paper works in such a manner as to lower a chute device 6 at the rolling contact portion, jumping of the trailing end is avoided not to cause disturbance of an image because the sheet 8 lacks firmness, and the leading end of the sheet is lower than the rolling contact portion.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used in electronic copying machines and the like to heat-fix an unfixed image, for example, a toner image, on an image support button such as paper.
The present invention also relates to a fixing device comprising a heating roll and a pressure roll that press and roll into contact with each other, and a chute device that guides an image support material carrying an unfixed image to a rolling contact portion between the two rolls.

2. Description of the Related Art In the chute device of this fixing device, the height of the inlet of the fixing device, which is the pressure rolling contact portion of the heating roll and the pressure roll, and the tip of the chute device is determined to ensure the running properties of thick paper such as postcards and the wrinkles of the paper. , is an important parameter regarding image disturbance, etc.

Conventionally, when the leading edge of an image support material such as paper hits the pressure roll of the fixing device and then enters the fixing device, wrinkles tend to occur, especially when the image support material is paper. As shown, the height of the tip of the chute 1 is set higher than the entrance of the fixing device, which is the pressure rolling contact portion of the heating roll 2 and the pressure roll 3.

As a result, stiff paper such as postcards hits the heating roll 2 and stops at the entrance of the fixing device, resulting in a jam at the entrance of the fixing device.

In order to solve this problem, conventional methods have been used as shown in Figure 4.
A weighted star wheel 4 is disposed opposite to the upper surface of the transport 5.

Problems to be Solved by the Invention The above-mentioned conventional means cause copying stains and jamming of weak paper such as second base paper.

In addition, by setting the tip of the chute 1 higher than the entrance of the fixing device, the trailing edge of the paper is raised.
The unfixed image hits the heating roll 2, causing image disturbance.

Means and Effects for Solving the Problems The present invention has been made in view of the above-mentioned problems, and the chute device of the fixing device is composed of a chute body and an elastically deformable sheet fixed to the tip of the chute body. This chute device has a configuration in which the chute body is oriented at a position lower than the entrance of the fixing device, and the leading edge of the sheet is brought into contact with a pressure roll at a position lower than the entrance of the fixing device. The image support material that has been removed is conveyed from the chute main body along the sheet toward a position lower than the entrance of the fixing device.

Example An embodiment of the present invention will be described based on FIGS. 1 and 2.

In the figure, 6 is a chute device, and this chute device 6 consists of a chute body 7 and a sheet 8 with one end attached to the lower side of the tip of this chute body 7.

Like the conventional chute 1, the chute body 7 is made of a rigid material such as metal or plastic. The sheet g is made of a heat-resistant plastic material such as polyamide or polyimide, and has a thin thickness of 100 to 300 μm and is elastic.

As shown in FIG. 2, the chute device 6 configured as described above is arranged so that the leading edge of the sheet 8 is located approximately 1 to 2 inches away from the inlet of the fixing device, which is the pressure rolling contact portion between the heating roll 2 and the pressure roll 3. The chute body 7 is mounted in such a manner that it is in contact with the pressure roll 3 and faces from an extension of the transport 5 to a position lower than the entrance of the fixing device.

In the above configuration, the paper carrying the unfixed image is transported from the transport 5 to the chute body 7 and the sheet 81C? j is conveyed toward a position lower than the entrance of the fixing device. Therefore, the paper remains flat until it enters the fixing device, and the occurrence of wrinkles is reduced to a minimum. Further, since the tip of the chute device 6 is lower than the entrance of the fixing device, stiff paper such as postcards is directly conveyed to the entrance of the fixing device, thereby preventing jams in this area.

Further, the paper at the entrance of the fixing device is in the chute family f6.
However, since the tip of the chute device 6 is lower than the entrance of the fixing device, and the tip is made of a stiff sheet 8, the trailing edge of the paper is prevented from flying up. This prevents image distortion.

Effects of the Invention According to the present invention, it is possible to prevent wrinkles in image supporting materials with a weak width such as paper, to prevent jams in image supporting materials with strong stiffness such as postcards, and to prevent image disturbance. A fixing device having the above structure can be obtained at low cost. Furthermore, the chute device in the fixing device according to the present invention has a tolerance of ±0 in its mounting position compared to the conventional chute.
．． 5■, whereas it is ±l-0m+, the mounting tolerance can be widened, and the assemblability and serviceability of the chute device can be improved.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show an embodiment of the present invention, Fig. 1 is a side view showing only the chute device, Fig. 2 is an overall side view, and Fig. 3 and Fig. 4 show a conventional example. FIG. 2 is a heating roll, 3 is a pressure roll, 6 is a chute device,
7 is the chute body, 8 is the seat.

Claims (1)

[Claims] A heating roll 2 and a pressure roll 3 that are pressed and rolled into contact with each other,
In a fixing device such as an electronic copying machine, which includes a chute device 6 that guides the image support material to the rolling contact portion of both rolls 2 and 3,
The chute device 6 is composed of a chute body 7 and an elastically deformable sheet 8 fixed to the tip of the chute body 7. , a fixing device characterized in that the leading edge of the sheet 8 is brought into contact with the pressure roll 3 at a position lower than the entrance of the fixing device.