JP2002091192A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that restricts friction between a carrying guide plate and a transfer material on a carrying path and prevents print displacement and a jam. SOLUTION: The image forming device has an image carrier means 13 which is capable of holding a toner image thereon, a toner image forming means 4 which forms a toner image on the image carrier means 13, and a carrying means which carries a transfer material 32 via the carrying guide plate 21. The image forming device also has a transfer means 5 which transfers the toner image, formed on the image carrier means 13 by the toner image forming means 4, to the transfer material 32, carried directly or indirectly by the carrying means, in a predetermined transfer position. In the image forming device, a Mylar 22 having a hole is attached to the carrying guide plate 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, a toner image formed on a photosensitive drum is transferred to a recording material such as a transfer material at a transfer position and then fixed to form an image.
At this time, the transfer material is pulled out one by one from a paper feed cassette by a pickup roller, and is conveyed to a transfer position with timing controlled by a registration roller. At the transfer position, the transfer material is brought into close contact with the photoreceptor drum to increase transfer efficiency and reduce transfer residual toner, and finally obtain a transfer image free of dust and the like, thereby finally achieving high quality. Images can be obtained. For this purpose, a transfer guide plate is provided on the transfer path to guide the transfer material to the transfer position.

However, when the transfer material comes into contact with the conveyance guide plate, there is a problem that the transfer of the transfer material is hindered and the transfer position with respect to the transfer material shifts or the amount of untransferred toner increases. For this purpose, Japanese Patent Application Laid-Open No. H11-288188 discloses that a sheet made of PET (polyethylene terephthalate) is made conductive, and is adhered to a guide plate installed on a main body made of sheet metal (conductive) to thereby form a transfer material and a sheet. There is disclosed an image forming apparatus that prevents electrostatic attraction with the image forming apparatus, and that can reliably transfer a transfer material without transfer failure.

[0004]

However, in the image forming apparatus proposed above, it is not sufficient to accurately guide the transfer material to the transfer position, and the transfer residual toner is generated and the transfer position is shifted. There were many images with dust and smudges. Accordingly, it is an object of the present invention to provide an image forming apparatus that suppresses friction generated between a transfer guide plate and a transfer material on a transfer path, thereby preventing printing displacement and jam.

[0005]

According to a first aspect of the present invention, there is provided an image bearing member capable of holding a toner image, and a toner image formed on the image bearing member. A toner image forming unit, a conveying unit that conveys a transfer material via a conveying guide, and a toner image formed on the image carrier unit by the toner image forming unit, which is directly or indirectly conveyed by the conveying unit. An image forming apparatus for attaching a mylar having a hole to the transport guide, in a transfer charging unit for transferring the transfer guide to the transfer material at a predetermined transfer position. According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein a mylar with a fold is attached to the transport guide plate.
According to a third aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein a mylar having an aperture shape formed by a heat treatment is attached to the transport guide plate.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram schematically showing a mechanism of an image forming process according to an embodiment of the present invention. FIG. 2 is an enlarged view showing a transfer position in the image forming process of FIG. FIG. 3 is a diagram showing a transport guide plate used in the image forming apparatus according to the first aspect. FIG.
FIG. 4 is a view showing a transport guide plate used in the image forming apparatus according to the second embodiment. FIG. 5 is a view showing a transport guide plate used in the image forming apparatus according to the third aspect.

In FIG. 1, a photosensitive drum 13 serving as an image carrier is rotated by a motor (not shown) to uniformly charge the surface of the photosensitive drum 13 as a charging device 1 and a laser writing system as an exposure device 2. Unit. The transfer belt 7 is an intermediate transfer member. The transfer belt 7 is provided between rotating rollers, and is rotated by rotating the rotating rollers. The photosensitive drum 13 and the transfer belt 7 are in contact with each other at a rotating roller portion of the photosensitive drum 13. In the transfer area in contact, on the transfer belt 7 side,
A transfer roller 25, which is a transfer means having conductivity, is in contact with the back surface of the transfer belt 7 under predetermined conditions.

Here, the image forming operation of the image forming apparatus according to the embodiment of the present invention will be described. After the photosensitive drum 13 is uniformly charged by the charging device 1, the photosensitive drum 13 is scanned and exposed by the laser exposure device 5 based on image information, and an electrostatic latent image is formed on the surface. The electrostatic latent image formed here is developed by the developing device 4 as a toner image forming unit, and an image is formed on the photosensitive drum 13. The image formed on the rotating photosensitive drum 13 is transferred onto the transfer belt 7 rotating in synchronization with the photosensitive drum 13. The toner image on the transfer belt 13 is transported from a paper cassette (not shown) to a transfer area by a transport means such as a transport guide plate 21 via a pair of registration rollers 11, and is transferred onto the transfer material 32 by the transfer roller 14. After the transfer is completed, the transfer material 32
The image is fixed by a fixing device (not shown), and the image is completed.
The print image is discharged to a discharge stack unit via a discharge roller. The cleaning device 9 including a cleaning blade that always contacts the photosensitive drum 13 and cleans the toner on the photosensitive drum 13, the waste toner collecting device, and the cleaning device 8 for the transfer belt 7 during the image forming operation. The toner image is held at a position separated from the surface of the transfer belt 7 and is brought into contact with the surface of the transfer belt 7 after the toner image is transferred onto the transfer material 32 described above.

As shown in FIG. 2, the transfer means guides the transfer material 32 to the transfer area by the transfer guide plate 21 before the transfer area. Even if the transfer guide plate 21 in front of the transfer area is made conductive to prevent charging with the transfer material, it is difficult to accurately guide the transfer material 32 to the transfer area if the friction is large. Therefore, in the present invention, as shown in FIG.
The frictional resistance between the transfer material 32 and the transport guide plate 21 is reduced,
Problems such as jams caused by the transfer material 32 and the conveyance guide plate 21 can be prevented.

FIG.
May be a mylar 23 in which a fold is formed in a rib shape. Since the transfer material 32 is conveyed only in contact with the crests of the folds, the frictional resistance in conveyance can be reduced, as with the mylar 22. This can prevent a problem such as a jam caused by the transfer material 32 and the transport guide plate 21. Furthermore, what is stuck on the transport guide plate 21 may be a mylar 24 having a drawn shape as shown in FIG. As in the case of the mylars 22 and 23, the frictional resistance in conveyance can be reduced. Thereby, the transfer material 32
And the conveyance guide plate 21 can prevent problems such as jamming. When the transfer guide plate 21 is conductive such as a sheet metal and leaks along the transfer material 32 at the time of transfer and there is a possibility of transfer failure, another one is used for the perforated mylar 23.
By sandwiching a mylar having no sheet holes therebetween, electrical resistance is increased to prevent leakage and to prevent a decrease in transfer rate and the like.

[0011]

As described above, the image forming apparatus of the present invention prevents the electrostatic attraction between the transfer guide plate and the transfer material, and enables the transfer of the transfer material without jam.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a mechanism of an image forming process according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing a transfer position in the image forming process of FIG. 1;

FIG. 3 is a view showing a transport guide plate used in the image forming apparatus according to the first embodiment.

FIG. 4 is a view showing a conveyance guide plate used in the image forming apparatus according to the second embodiment.

FIG. 5 is a view showing a transport guide plate used in the image forming apparatus according to the third embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Charging device 2 Exposure device 3 Potential sensor 4 Developing unit 5 P sensor 7 Transfer belt 8 Belt cleaning device 9 Drum cleaning device 10 Static elimination device 11 Paper transfer 12 Separation unit 21 Transport guide plates 22, 23, 24 Transport mylar 25 Transfer roller 26 Separation charger 27 Lubricant application device 28 Belt cleaning blade 29 Waste toner receiver 31 Registration roller 32 Transfer material

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[Procedure amendment]

[Submission date] October 13, 2000 (2000.10.
13)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

[Title of the Invention] Image forming apparatus

Claims (3)

[Claims] 1. An image carrier means capable of carrying a toner image, a toner image forming means for forming a toner image on the image carrier means, and a transport means for transporting a transfer material via a transport guide plate; Transfer means for directly or indirectly transferring the toner image formed on the image carrier means by the toner image forming means to the transfer material conveyed by the conveyance means at a predetermined transfer position; An image forming apparatus characterized in that a mylar with a hole is attached to the image forming apparatus. 2. The image forming apparatus according to claim 1, wherein a creased mylar is attached to the transport guide plate. 3. The image forming apparatus according to claim 1, wherein a mylar having a drawn shape formed by heat treatment is attached to the transport guide plate.