JPS6290675A - Transfer device for color copying machine - Google Patents

Abstract

PURPOSE:To prevent a transfer material from being attracted to a photosensitive drum or a toner image from being disordered owing to aerial discharge right after transfer by providing a conductive brush or a rod member wound with conductive fibers nearby a transfer drum and the photosensitive drum at the downstream side of a transfer area. CONSTITUTION:The grounded conductive brush or rod member wound with conductive fibers is provided nearby the photosensitive drum and transfer drum at the downstream side of the transfer area so as to prevent the transfer material which is released from being gripped from being attracted toward the photosensitive body after the end of a transfer process and peeling discharge from occurring right after the transfer. This conductive brush 15 is formed by embedding a brush 14 of carbon fiber, etc., is a conductive base part 13 and thus the conductive member is formed as a brush type, so respective fibers operate as pin electrodes, so that superior effect to prevention against the peeling discharge is obtained. The rod type member is formed by winding a support rod 16 with conductive fibers 17 and a net of about 70 meshes is formed of conductive fibers and wound around the rod member to obtain a preferable rod member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transfer device for a color copying machine, which allows a transfer material to be smoothly conveyed to a fixing section after being released from a transfer drum gripper.

[Conventional technology]

In the color copying method, as shown in FIG. 2, a photoreceptor 2 uniformly charged by a charged corotron 11 is subjected to an image exposure source 4 through a color separation filter 3, and a latent image is formed by toner of a predetermined color. A transfer material 8 is developed by a developing device 5 having a toner image, and this toner image is held by a gripper 7 on a transfer drum having an insulating support screen wrapped around the support drum.
A color image is formed by repeating the process of transferring the image by the transfer corotron 9 a plurality of times.

The transfer material 8 on the transfer drum receives a discharge current of opposite polarity to the toner image from the transfer corotron 9 while in contact with the developed toner image on the photoreceptor drum, and the toner image is transferred, but only after a predetermined number of transfers. After the transfer is completed, the grip on the transfer drum is released, the transfer material is conveyed while being electrostatically attracted to the support screen, is peeled off by the peeling finger 9, and sent to the fixing device 11.

However, in such a copying machine, when the darnper is released, the transfer material may be peeled off before it is conveyed to a part of the peeling finger.

This is because the electrostatic attraction force of the transfer material to the support screen is weak.
This phenomenon occurs because the transfer material is subjected to the force of attraction toward the photoreceptor.

Apart from such a peeling phenomenon, image disturbance may occur when the transfer material is separated from the photosensitive drum. That is, the air discharge that occurs when the transfer material is peeled off from the photosensitive drum affects the electric charge of the toner.

As a device to prevent such a phenomenon, a needle-shaped conductive member is provided immediately after the transfer material passes through the transfer area to increase the electrostatic attraction force of the transfer material and to reduce air discharge. A device has been proposed (Japanese Patent Laid-Open No. 198478/1983). However, needle-shaped electrodes are difficult to handle and easily damage photosensitive drums, etc.Also, a device in which a wire-shaped conductive member is provided has been proposed (Japanese Patent Application Laid-open No. 186760/1983).
The L pole has the disadvantage of causing trouble due to contact with the photoreceptor due to vibration (and being easily disconnected).

Furthermore, disturbances in the transferred image may be caused by static loads on the peeling finger. As the peeling fingers are made of plastic material to avoid damaging the transfer material support screen, static charges tend to accumulate, especially when the adsorption force between the support screen and the transfer material is strong.
In addition, low temperature and low humidity have a strong effect on toner images.
White lines may appear in the image area.

[Problem that the invention seeks to solve]

An object of the present invention is to perform development 11! on a transfer material on a transfer drum.
In the color copying method, in which a color image is formed by transferring multiple times, the transfer material may be sucked onto the photosensitive drum when the transfer material is released from the gripper after the transfer process, or the toner image may be disturbed by air discharge immediately after transfer. The purpose of the present invention is to provide a transfer device that does not cause any problems.

Another object of the present invention is to provide a transfer device for a color copying machine that does not cause disturbance to the artist when the transfer material is peeled off with a peeling finger after the transfer process is completed.

[Means and effects for solving the problems] The present invention
As shown in the figure, after transferring the developed image multiple times to the transfer material on the transfer drum to form a color image, release the grip,
In a transfer device of a color copying machine in which a transfer material is peeled off by a peeling finger and conveyed to a fixing section, a rod-shaped member 12 having a conductive brush or conductive fiber wrapped around the transfer drum and the photosensitive drum on the downstream side of the transfer area is used. This transfer device is characterized by the fact that it is equipped with

In addition, in the present invention, the volume resistivity is 10' to 10' in order to prevent disturbance of the transferred image due to static charges on the peeling finger.
10Ω・Sub and/or surface resistivity is 10°~101
The peel pit finger is formed using a 0Ω material.

FIGS. 3 and 4 are perspective views of examples of conductive members used in the transfer apparatus of the present invention, which increase the adhesion force between the transfer material after transfer M and the support screen.

The third factor is that a conductive brush made of carbon fiber or the like is embedded in the conductive support portion 13. By using the conductive member as a brush, each fiber acts as a pin electrode, and is therefore highly effective in preventing peeling discharge.

FIG. 4 shows a rod member 16 in which conductive fibers 17 are wound. As the rod member 16, in addition to a metal rod having a diameter of 100 μm or more, an insulating rod can be used. In the latter case, the fibers are grounded.

Preferably, a 70-mesh 8-degree net is formed from conductive fibers and wound around a rod member. In the example shown in FIG. 4, troubles due to wire breakage do not occur, and since the bar member is fixed, the toner image is not disturbed by vibration.

In the present invention, since the conductive member is provided, the adhesion force between the transfer material and the support screen is increased, so that the peeling finger can cause the Il! Disturbance of the li image is likely to occur. Therefore, the resistance of the peeling finger is lowered.
Prevents static charge build-up. As a result of experiments, it was found that by mixing conductive powder such as finger material (carbon), the toner can be rubbed so that the volume resistivity is 10' to 1010 Ω and the image and/or surface resistivity is about 100 to 1010 Ω. Painter's disorder (occurrence of white streaks) is not observed (
became.

〔Effect of the invention〕

In order to prevent the transfer material whose grip has been released after the transfer process is completed from being attracted to the photoreceptor side, the present invention is designed to prevent the transfer material from being attracted to the photoreceptor side after the transfer process is completed. conductive brush or 251! This transfer device is equipped with a rod-shaped member wrapped with sexual fibers, and uses a low-resistance material that does not accumulate static charge as a peeling finger.It does not generate the peeling discharge of direct transfer moxibustion, and has a strong adsorption force of the transfer material. Even though the height is increased, no image disturbance occurs due to the peeling finger.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a color copying machine using the transfer device 1 of the present invention, Fig. 2 is a schematic diagram of a conventional color copying machine, and Figs. 3 and 4 are each used with the transfer device of the present invention. FIG. 2 is a perspective view of a conductive member for preventing peeling discharge. Symbols in the figure: 1... band icorotron; 2... photosensitive drum; 3.
・・Color separation filter-4・・1-plane image exposure: 5・・・・
Developing machine: 6... Transfer drum near... Gripper; 8
... Transfer material; 9... Transfer corotron; 10... Peeling finker:] 1... Fixing device: 12... Conductive member: 13... Supporting member; 14... Brush;・・・
- Conductive brush; 16... Support rod; 17... Conductive fiber. Figure 1 Helmet Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. Color copying in which a developed image is transferred multiple times to a transfer material on a transfer drum to form a color image, and then the grip is released and the transfer material is peeled off with a peeling finger and transported to a fixing section. 1. A transfer device for a machine, characterized in that a conductive brush or a rod-shaped member wrapped with conductive fibers is provided near a transfer drum and a photoreceptor drum on the downstream side of a transfer area. 2. Volume resistivity as peeling finger is 10^0~10
＾1＾0Ω・cm and/or surface resistivity is 10＾0
The transfer device according to claim 1, characterized in that a material having a resistance of ~10^1^0 Ω is used.