JPS60205551A - Electrifying device - Google Patents

Abstract

PURPOSE:To prevent spread of a contactor consisting of a soft electrical resistor owing to bending by providing an insulating cap to one end of an electrifier having the contactor on a core material. CONSTITUTION:A cap 7 consisting of an insulating material is fitted and fixed to the end of an electrifying roller so that a contactor 3 is prevented from spreading owing to bending and projecting from the end face 6a of a photosensitive layer 6. A material for the cap 7 is selected according to the using condition of the electrifying roller and the material of an object to be electrified and is made of polycarbonate into a cylindrical shape, the end face 7a of which is positioned in the boundary part between the substrate 5 and the photosensitive layer 6. The spread of the contactor 3 owing to bending is prohibited by the end face 7a of the cap 7, by which the contact of the contactor with the substrate 5 is prevented and therefore stable electrification is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for charging a charged body such as a photoreceptor of an electrophotographic copying machine.

Conventional technology A corona charger is known as a charging device for electrophotographic copying machines, but it is dangerous because it uses high voltage, and it also generates ozone. A contact charging type charging device has been developed in which a charging object is brought into contact with the object to be charged and a voltage is applied to charge the object.

However, with this charging device, when the brush comes into contact with the object to be charged, the fibers bend and spread, contacting the substrate of the object and causing the charge to leak to the substrate. It has the disadvantage that it cannot be charged.

That is, the object to be charged is a substrate provided with a photosensitive layer, and when the fibers are bent and spread, they protrude from the end surface of the photosensitive layer and come into contact with the substrate.

To prevent this, the fibers may be made more rigid so that they are bent so that they do not spread out, but this has the disadvantage of damaging the surface of the object to be charged.

Purpose of the Invention When a charger equipped with a large number of contacts made of flexible electrical resistors is brought into contact with an object to be charged, it is possible to prevent the contact from falling and causing a slander. The purpose is to prevent touching.

Constituent of the Invention: A charger having a core material provided with a large number of contacts made of flexible electrical resistors, in which an insulating cap is provided at one end of the charger, and the cap prevents the contacts from bending and spreading.

Embodiment FIG. 1 is an overall perspective view, in which a charger 1 has a cylindrical core material 2.
The charging roller has a large number of contacts 3 made of flexible electrical resistors implanted on the surface of the charging roller, and is brought into contact with the surface of the object 4 to be charged and driven to rotate synchronously, and a voltage is applied thereto.

The charged body 4 has a cylindrical shape with a photosensitive layer 6 provided on a substrate 5, and is rotated by a rotating portion ah.

Because of this, when the charger 1 is brought into contact with the object to be charged 4, the contactor 3 bends and spreads, protrudes beyond the end surface 6α of the photosensitive layer 6, and comes into contact with the substrate 5, and the applied voltage is applied to the substrate. It leaks to 5 and cannot be charged.

Therefore, in the present invention, a cap 7 made of an insulating material is fitted and fixed on the end of the charging roller to prevent the contact 3 from bending and spreading beyond the end surface 6α of the photosensitive WI 6.

The material of the cap 7 is selected depending on the usage state of the charging roller and the material of the charged object, and in the embodiment, it is made of polycarbonate and has a cylindrical shape 9, the end surface 7α of which is located at the boundary between the substrate 5 and the photosensitive layer 6. There is.

In this manner, the end surface 7α of the cap 7 prevents the contactor 3 from bending and spreading, thereby preventing it from coming into contact with the substrate 5, thereby allowing stable charging.

In addition, by fitting the cap 7'f, the effective length of the charging roll, that is, the length of contact between the contact 3 and the charged object 4 can be shortened. The width of the transfer paper can be made wider or narrower, and only the width of the transfer paper can be charged, and unnecessary areas are not charged, and the portion beyond the middle of the transfer paper is not charred, so it is transferred to the charged object 4. When the developed image is transferred to the transfer roller by contacting the roller, the portions of the transfer roller other than the transfer width are not soiled, which is preferable.

For example, in a copying machine that has a charged body that can transfer up to 34-size transfer paper, the length of the charging roll is set to 34-size transfer paper.
If you use a cap 7 with a length that matches the paper size and a length that is equal to the difference between the 34 paper size and the 74 paper size, you can remove the cap 7 when copying E4 paper, and remove the cap 7 when copying 74 paper. By attaching the cap 7, the object to be charged 4 can be charged by a width corresponding to a 34-size size and a width corresponding to a 74-size size.

The charger 1 has a plate-shaped core material with a large number of contacts provided thereon so that their tip surfaces have the same shape as the surface of the object to be charged to form a charging bar, and a cap is fitted to the end of the charging bar. It's okay.

Effects of the Invention Since the contactor 3 can be prevented from bending and spreading and from coming into contact with the gold cap 7, the applied voltage will not leak to the substrate 5 portion and can be stably charged.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall perspective view;
Figure 2 is a cross-sectional tooth of the cap portion. 1 is a charger, 2 is a core material, 3 is a contactor, 4 is a charged object, 5
is the board, and 7 is the cap. Applicant Fuji Xerox Co., Ltd. Kinsha 1 Agent Patent attorney Masaaki Yonehara Patent attorney Tadashi Hamamoto

Claims (1)

[Claims] A charging device having a core material 2 with a large number of contacts 3 made of flexible electrical resistors is arranged so that the contacts 3 are in contact with the surface of a charged object 40, and a voltage is applied to charge the charged object. Charged body 4
1. A charging device for charging the surface of a charger 1, characterized in that an insulating cap 7 is attached to an end of the charger 1.