JPS6377074A - Transfer device - Google Patents

Abstract

PURPOSE:To form an image of good quality without any scatter of toner by composing a control plate of an insulating member and also constituting a conveyor guide plate which guides a transfer form to the contact point of a photosensitive drum by using an elastic member, and specifying the gap between the conveyance guide plate and photosensitive drum. CONSTITUTION:The conveyor guide plate 5 made of the insulating elastic member of polyethylene terephthalate, etc., is adhered on the photosensitive drum side of the form conveyance guide 4. Further, a projection guide 52 is formed at a folded corner part and the gap between the projection guide 52 and photosensitive drum 1 is different with the angles of the form conveyance guide 4, conveyance guide plate 5, etc., to the photosensitive drum 1, but set to about 1mm. The transfer form A is sent to the photosensitive drum by being guided by the form conveyance guide 4 and conveyance guide plate 5. In this case, the point where the transfer form A contacts the photosensitive drum 1 is denoted as a contact point P, where even transfer forms are the same without reference to the difference in elasticity. When the transfer form A is charged electrostatically in front of the contact point P in the rotating direction of the photosensitive drum, no toner is scattered over the transfer paper.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a transfer device for transferring toner on the surface of a photoreceptor drum onto a conveyed transfer sheet in an electrophotographic copying machine or the like.

(b) Conventional technology In electrophotographic copying machines, etc., an electrostatic latent image is formed on the surface of a photoreceptor drum, triboelectrically charged toner is electrostatically attached to this electrostatic latent image, and A single layer of toner is formed on the transfer paper by electrostatically transferring the toner to the transfer paper whose back side is charged by a corona ion flow. Figure 3 shows the above process.
FIG. 2 is a diagram illustrating the configuration of a transfer device that executes a process of transferring toner to transfer paper. A charger box 2 is disposed facing the photosensitive drum 1, and a charger line 3 is stretched in the charger box 2. A high voltage is applied to this charger cotton 3 to generate a corona ion flow. A transfer paper is conveyed from the paper urethral guide 4, and as the back surface of the transfer paper is charged by the corona ion flow as described above, toner is transferred from the photoreceptor drum 1 onto the surface of the transfer paper.

(C1 Problem to be Solved by the Invention When transferring toner to transfer paper in this manner, it is desirable that the toner is transferred to the transfer paper after the transfer paper is brought into contact with the surface of the photoreceptor drum. This is because when the transfer paper comes into contact with the photoreceptor drum, the toner image formed on the surface of the photoreceptor drum can be reliably transferred as is to the transfer paper.

However, in the conventional transfer device as described above, the third
As shown in the figure, before the transfer paper A comes into contact with the surface of the photoreceptor drum 1, the back surface of the transfer paper A is charged by the corona ion flow, and the toner on the charged area and the surface of the photoreceptor drum 1 is charged. A Coulomb force is generated between the transfer paper and the transfer paper, and the transfer paper may fly to the charged area. As a result, toner scattering appears on the image formed on the transfer paper, causing a significant deterioration in image quality.

Furthermore, when using transfer paper that does not have stiffness, if the distance between the paper conveyance guide 4 and the photoreceptor drum 1 is too large, the contact point of the conveyed transfer paper with the photoreceptor drum 1 will become unstable; In some cases, the above-mentioned toner scattering occurs frequently, and in other cases, it is impossible to obtain an image without toner scattering, so that the quality of the formed image becomes unstable.

This invention prevents the transfer paper from being charged before it comes into contact with the surface of the photoreceptor drum, and also adjusts the distance between the paper conveyance guide and the photoreceptor drum to be appropriate depending on the stiffness (thickness) of the paper. It is an object of the present invention to provide a transfer device that can obtain high-quality images without toner scattering regardless of the stiffness of paper by changing the stiffness of the paper.

(Means for Solving Problem d1) The transfer device of the present invention regulates the charging area by the transfer charger to be forward in the rotational direction of the photoreceptor drum than the point where the transfer paper contacts the surface of the photoreceptor drum. The regulating plate is made of an insulating material, and the conveyance guide plate for guiding the transfer paper to the contact point of the photoreceptor drum is made of an elastic material, and the distance between the conveyance guide plate and the photoreceptor drum is set to 1. It is characterized by being made into a crane.

(e) Effect In the present invention, the region charged by the transfer charger is regulated by the regulation tent, so that only the area in front of the point where the transfer paper contacts the surface of the photoreceptor drum is charged.

Therefore, the transfer paper is not charged before it comes into contact with the photoreceptor drum, and there is no toner flying to the transfer paper, improving image quality.Also, the regulation plate is made of an insulating material. This eliminates leakage between the charger wire and the regulation plate, and when too much current flows between the charger line and the regulation plate, the current between the charger line and the photoconductor drum decreases, making it difficult for the transfer paper to be charged. There will be nothing to become.

In addition, since the distance between the conveyance guide plate that guides the transfer paper to the contact point and the photosensitive drum is approximately 1 ml, even if the transfer paper is weak (E), it will not be possible to transfer the transfer paper with low stiffness. Since the paper is uniformly fed along the paper transport guide to just before the point of contact with the photoreceptor drum and is adhered to the photoreceptor drum, all images can be of the same quality. Furthermore, since this conveyance guide plate is made of an elastic member, if the transfer paper is stiff, the regulation plate will be pushed and bent, and the transfer paper will be at the point of contact with the photoreceptor drum. Contact the photoreceptor drum.

(f) Embodiment FIG. 1 is a schematic diagram of a transfer device according to an embodiment of the present invention.

The photosensitive drum 1 is a cylindrical body having a photoconductive layer formed on its surface, and is rotatable in a clockwise direction.

A charger box 2 is disposed facing the photosensitive drum l. The charger box 2 is made of a conductive member such as metal, has an L-shaped cross section, and is connected to the photoreceptor drum 1.
The side facing the paper conveyance guide 4 and the side facing the paper conveyance guide 4 are open. A charger line 3 is stretched around the charger box 2 along the rotation axis of the photosensitive drum 1. A high voltage is applied to this charge line 4, and a corona ion flow is generated.

Like the charger box 2, the paper conveyance guide 4 is also made of a conductive member such as metal. The end of the paper conveyance guide 4 is slightly bent so as to face the photoreceptor drum, forming a parallel piece 41. A conveyance guide plate 5 made of an insulating elastic material such as polyethylene terephthalate (PET) is adhered to the photosensitive drum side of the paper conveyance guide 4. This conveyance guide plate 5 is adhered along the paper conveyance guide 4, and its tip portion forms a regulating portion 51 parallel to the photoreceptor drum 1, similar to the flat piece 41.

Furthermore, a protruding guide 52 is formed at the bent corner. When the protruding guide 52 is pressed against a stiff (thick) transfer paper, the protruding guide 52 is bent. The distance between the protrusion guide 52 and the photoreceptor drum 1 is about 1-fold, although it varies depending on the angle of the paper conveyance guide 4, the conveyance guide plate 5 (the protrusion guide 52), etc. relative to the photoreceptor drum 1.

The paper conveyance guide 4. The transfer paper A is guided by the conveyance guide plate 5 (protrusion guide 52) and is sent to the photoreceptor drum. Here, the point where the transfer paper A contacts the photoreceptor drum 1 is defined as a contact point P. This contact point P will be described later, but it is almost the same whether the transfer paper has a strong stiffness or the transfer paper has a weak stiffness.

Transfer paper A contacts point P with respect to the rotational direction of the photoreceptor drum
If the transfer paper was previously charged (on the left side in the figure), the phenomenon of toner flying onto the transfer paper does not occur. Therefore, a regulating portion 51 is formed on the side of the flat piece 41 facing the photosensitive drum 1. The regulating portion 51 prevents the corona ion flow from the charger vA3 from being irradiated after the contact point P (on the right side in the figure).

With the above configuration, when the transfer paper is thin and has a weak stiffness as shown in FIG. The photoreceptor drum 1 is guided to a position approximately at a contact point P and comes into contact with the photoreceptor drum 1 rotating clockwise. At this time, the gap between the photoreceptor drum 1 and the protruding guide 52 is only about 1++n, and even if there is paper with a weak stiffness, it contacts the photoreceptor drum 1 at the contact point P. In addition, when the transfer paper C is thick and has a strong stiffness as shown in FIG. Although it is in contact with the photoreceptor drum 1
rotates clockwise, a clockwise force is applied to the transfer IC. Since this transfer paper C has a strong stiffness, it presses the protrusion guide 52 clockwise to give it flex. As a result, the transfer paper C contacts the photosensitive drum 1 at the contact point P and is conveyed clockwise. In this way, even transfer paper with weak stiffness and transfer paper with strong stiffness can be brought into contact with the photosensitive drum l at the contact point P in the same manner.

Since the corona ion flow generated by applying a high voltage to the charger line 3 is not irradiated beyond the contact point P where the transfer paper B or C contacts the photoreceptor drum 1 (on the right side in the figure), the photoreceptor The toner on the surface of the body drum 1 is not attracted by the transfer paper that is not adhered to the photosensitive drum and flies to the transfer paper, and the toner does not fly off to the transfer paper.

In addition, since the conveyance guide plate 5 (regulating plate 51) is made of an insulating (elastic) material such as PET, the charger wire 3
In addition to eliminating leakage between the charge line 3 and the regulation part 51, too much current flows between the charge line 3 and the regulation part 51, resulting in a decrease in the charge line-to-photoreceptor drum current, making it difficult for the transfer paper to be charged. It will never happen.

Furthermore, in this embodiment, in order to prevent the legal regulation section 51 from getting too close to the charger line 3, the conveyance guide plate 5 is bonded to the photosensitive drum 1 side of the paper conveyance guide 4, so the impedance of the charger line 3 becomes high. It never passes.

In this embodiment, the regulating plate (regulating portion 51) is formed integrally with the conveyance guide plate 5, but may be formed separately.

fg) Effects of the Invention According to the present invention, whether the transfer paper has a strong stiffness or the transfer paper has a weak stiffness, it contacts the photosensitive drum at the same contact point. Since the charging area of the transfer charger is regulated forward of this contact point with respect to the rotational direction of the photoreceptor drum, the transfer paper is unlikely to be charged before it contacts the photoreceptor drum. In other words, toner does not adhere to the transfer paper before the transfer paper comes into contact with the phosphor drum, and toner scattering does not occur in the formed image.

In this way, it is possible to obtain a high-quality image without toner scattering, regardless of the stiffness of the transfer paper.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a transfer device which is an embodiment of the present invention, Figs. 2 (A) and (B) are diagrams showing the state in which transfer paper is fed by this transfer device, and Fig. 3 is a diagram of a conventional transfer device. FIG. 2 is a schematic configuration diagram of a transfer device. 3-charger wire, 4-paper feeding guide, 5- cliff guide plate, 51-(corona ion flow) regulating section, 52-protruding guide. The second is B)

Claims (1)

[Claims] (1) A regulation plate is provided that regulates the charging area by the transfer charger forward in the direction of rotation of the photoconductor drum from the point where the transfer paper contacts the surface of the photoconductor drum, and this regulation plate is made of an insulating member. The transfer device is further characterized in that a conveyance guide plate for guiding the transfer paper to a contact point of the photoreceptor drum is made of an elastic member, and the distance between the conveyance guide plate and the photoreceptor drum is approximately 1 mm.