JPH03242660A - Toner image forming device - Google Patents

Abstract

PURPOSE:To prevent paper jamming from occurring by specifying the position of the rib of a guide plate. CONSTITUTION:In this device, a toner image on a photosensitive drum is trans ferred to a paper by a transfer device 4 and the paper is guided by the guide plates 5 and 7 to a fixing machine, where the paper is heated and fixing is performed, so that the toner image is formed. The rib 51 of the guide 5 is formed so that it may be a little non-coincident with the rib 71 of the guide 7 at the entrance of the fixing machine at most of the parts but it may be coincident with the rib 71 at a part where it approaches the guide 7. Thus, the paper is easily transferred from the guide 5 to the guide 7. Even though toner is stuck to the rib 51, it is not accumulated on the guide 7 because it is allowed to drop by the bent part of the rib 51.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention applies electrophotography to copiers, printers,
The present invention relates to a toner image forming apparatus such as a facsimile machine.

[Conventional technology]

Fig. 2 shows a cross-sectional view of a general toner image forming apparatus applying electrophotography. . Reference numeral 3 denotes a photosensitive drum, which is a photosensitive member, on which toner is placed in a developing section (not shown) using an electrostatic layer so as to correspond to a recorded image. Reference numeral 4 denotes a transfer device, in which the toner on the photosensitive drum 3 is transferred onto the paper l entering the transfer device. Reference numeral 5 denotes a first guide plate, which is formed to be inclined downward along the traveling direction of the paper 1 separated from the photoreceptor 3, and then inclined upward toward the fixing section 6. .

The entrance guide 7 of the fixing device is formed to face upward in accordance with the traveling direction of the paper 1. After passing through the entrance guide 7, the fixing roller 8. When passing through the pressure roller 9, the toner is fixed onto the paper l by the high-temperature fixing roller 8, becomes a perfect image, and is ejected to the outside of the apparatus by ejection rollers 10, 10'.

In such a configuration, normally the photosensitive drum 3 and the fixing a
Two guide plates are sequentially arranged between the two guide plates 6, and correspond to the first guide 5 and the fixing line entry guide 7. Also, the first guide 5. Both fixing line entry log guides 7,
In order to lower the resistance to the paper 1 and prevent the paper 1 from being contaminated by toner scattered on the surface that comes into contact with the paper 1, many hollow parts such as ribs are provided in the surface that comes into contact with the paper 1. There is.

The conventional rib arrangement is as shown in Fig. 3, where the rib position of the fixing line entry guide 7 and the rib position of the first guide 5 match, or as shown in Fig. 4, the rib position is staggered. There are many things that do not match due to their location. If the rib positions match, toner that has adhered to the ribs for some reason will be rubbed against the bottom surface of the paper 2 and adhere to the back surface of the paper 2, and when passing over the fixing line entry guide 7, the toner will be removed from the fixing line. It attaches to the entry guide 7 rib. This toner is melted by the high temperature atmosphere of the fixing device 6. By repeating this, toner adhesion on the fixing line entry guide 7 accumulates, obstructing the advance of the paper 1, and causing wrinkles in the paper 1.

Causes paper jams. On the other hand, if the rib positions do not match, when the paper enters the fixing line entry guide 7 from the first guide 5, the ribs on both sides do not match, so it collides with the ribs of the fixing line entry guide 7. , which could cause paper jams.

[Problem to be Solved by the Invention] Since the conventional toner image forming apparatus is configured as described above, there is a problem that paper jams occur regardless of whether the ribs match or do not match. Ta.

The present invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a toner image forming apparatus that does not cause paper jams.

[Means to solve the problem]

The toner image forming apparatus according to the present invention makes the ribs of the first guide 5 and the ribs of the fixing line entry guide 7 slightly mismatched in the normal paper l traveling section, and The positions of the ribs are made to coincide with each other in the vicinity of the portions where the line entry guides 7 and the guides 7 contact each other.

[Effect]

Since the ribs of the first guide 5 in this invention are located at positions slightly mismatched with the ribs of the fixing line entry guide 7 in most of their parts, paper jams due to toner accumulation as described above do not occur.

Further, since the ribs are aligned in the vicinity of the connecting portions of both guides 5 and 7, paper jams do not occur due to mismatched rib positions.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a toner image forming apparatus according to an embodiment of the present invention, and this figure shows a transfer machine 4. 5 is a top view of the first guide 5 and the fixing line entry guide 7. FIG. In the figure, the first guide 5
The rib 51 is slightly inconsistent with the rib 71 of the fixing line entry guide 7 in most of its parts, and coincides with the rib 71 of the fixing line entry guide 7 in the vicinity thereof.

That is, among the above-mentioned ribs, the rib 51 of the first guide plate 5 on the upstream side with respect to the image carrier traveling direction is similar to the rib 51 on the first guide plate 7 on the downstream side.
The rib 71 is provided so as to coincide with the rib 71 in the vicinity of the connecting portion, and gradually move toward the outside of the image carrier from the upstream portion of the adjacent portion.

This embodiment is constructed as described above, and since the ribs 51 and 71 are formed continuously between the guide 5 and the guide 7, the paper entering from the transfer device 4
travels along the rib 51 of the first guide 5, and the paper 1
The tip of the guide 7 passes through the first guide 5 and the fixing line enters the guide 7.
can be transferred to the rib 71 without any hindrance.

Furthermore, the rib 5 of the first guide 5 is formed in a straight line.
1 is bent near the boundary with the fixing line entry guide 7, so even if toner that has adhered to the paper for some reason adheres to the ribs of the first guide, the ribs will be removed by the bent portion of the ribs 51. Since the toner falls from the toner onto the guide surface of the guide 5, the toner does not accumulate on the guide 7, which has been a problem in the past.

〔Effect of the invention〕

As described above, according to the toner image forming apparatus according to the present invention, the ribs of the first guide and the ribs of the fixing line entry guide do not match in the normal traveling part, but match in the parts where they are close to each other. With this structure, an apparatus that does not cause paper jams can be constructed at low cost, and a highly reliable apparatus can be easily obtained.

[Brief explanation of drawings]

FIG. 1 is a top view showing a toner image forming apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of a conventional apparatus, and FIGS.
The figure is a top view showing a conventional toner image forming apparatus. In the figure, 1 is a sheet of paper, 5 is a divided first guide plate, 7 is another divided guide plate (fixing line guide),
51.71 is a convex portion (rib) on the guide plate. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In a toner image forming apparatus comprising a means for forming a toner image on an image carrier and a means for heating and fixing the formed toner image on the image carrier, a portion for performing the image formation and a portion for performing the heat fixing. A guide plate for guiding the image carrier, which is divided into two or more members in a direction perpendicular to the direction of movement of the image carrier, is provided between the guide plate and the guide plate, and the guide plate has a large number of convex portions on a surface in contact with the image carrier. The convex portions are located at mutually coincident positions near the portions where the respective guide plates touch each other, and the convex portions of the two guide plates are located at slightly mismatched positions at portions other than the contact portions. 1. A toner image forming device comprising: