JP2754908B2 - Transfer device in image forming apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device for preventing a discharge electrode wire from being cut in an image forming apparatus such as a copying machine or a printer.

2. Description of the Related Art An image forming apparatus such as a copying machine or a printer includes, for example, a charger, a developing device, a transfer charger, a charge eliminator for separation, a cleaning device, and a cleaner around a latent image carrier such as a photosensitive drum. An electric device is provided, and the photosensitive drum is uniformly charged in the dark state by corona discharge using a charger, and the original image is projected as a mirror image on the photosensitive drum, and the surface potential is attenuated according to the light and dark light image to reduce the light image. Is converted into an electrostatic latent image, a toner corresponding to the charge of the electrostatic latent image is adhered by a developing device to convert the toner image into a toner image, and transfer paper is superimposed on the toner image, and the toner is transferred to the back of the paper by a transfer charger. An electric field for moving the image is applied, the transfer paper is separated from the photosensitive drum by a separating static eliminator, and the toner image on the transfer paper is fused and fixed to the paper by heating or the like by a fixing device, and remains on the photosensitive drum after transfer separation. Cleaner and static elimination of toner and electrostatic latent image It is removed by a container.

In the above configuration, the transfer charger is configured such that a discharge electrode wire is stretched via a double-sided insulator in a grounded casing, and a high-voltage connection terminal is provided at one end of the discharge electrode wire. A corona discharge having a polarity opposite to the charging of the toner is applied to bring the paper into close contact with the photosensitive drum and simultaneously electrostatically attract the toner to the paper. At the time of this transfer, ozone is generated by corona discharge, and the ozone is chemically changed into nitrogen oxide to form a film on the photosensitive drum, which adversely affects uniform charging of the photosensitive drum. For this reason, an opening is provided at the bottom of the transfer unit casing to discharge ozone to the outside of the casing.

[Problem to be Solved by the Invention] However, in the conventional transfer charger,
If the transfer paper does not separate from the photosensitive drum and causes a jam, the transfer paper will bend into the transfer device casing and attempt to penetrate through the ozone discharge opening provided at the bottom of the casing. There is a problem that the electrode wire may be wound and cut.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a transfer device in an image forming apparatus capable of discharging ozone generated by corona discharge and preventing cutting of a wire for a discharge electrode. I do.

Means for Solving the Problems and Action Therefor To achieve the above object, a transfer device in an image forming apparatus of the present invention is provided around a photosensitive drum, and has openings in a part of upper and lower bottom walls. A casing in which a portion is formed, a discharge electrode wire stretched in the casing, and a plurality of locking pieces made of an insulating material attached so as to straddle the opening outside the bottom wall of the casing. It is characterized by having. As the insulating material, other than a synthetic resin, a material made of an activated carbon sheet absorbing ozone or a neutralizing agent chemically changing nitrogen oxides is used. Further, a suction duct may be provided at a lower portion of the casing, and a plurality of locking portions and a suction port may be formed on the upper surface of the suction duct so as to face the opening.

In the present invention, when the transfer paper is jammed without separating from the photosensitive drum, the transfer paper bends and enters the casing of the transfer charger, and further penetrates through an ozone discharge opening provided at the bottom of the casing. In this case, the transfer paper is stopped by the locking piece attached to the opening or the locking part of the suction duct provided below the opening, so that the discharge electrode wire is prevented from being cut.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a transfer device 1 in the image forming apparatus of the present invention.
FIG. 2 is a plan view showing an embodiment, FIG. 2 is an overall configuration diagram of an image forming apparatus according to the present invention, FIG. 3 is a sectional view showing another embodiment of a transfer device in the image forming apparatus of the present invention, and FIG. Third
It is a partial perspective view of a figure.

2, around a photosensitive drum 1, a charger 2, a developing device 5 having a developing sleeve 3, a sheet transport device 6 for supplying a sheet to the photosensitive drum 1, a transfer charger 1
3, a paper transport device 21 having a static eliminator 17 for separation, a belt 22 and a driving roller 23 for transporting transfer paper to a fixing device (not shown), a transfer paper peeling claw 25, a cleaning brush 27 and a cleaning blade 29 Cleaning device 26
Are arranged.

The paper transport device 6 includes an upper carry-in member 7, a lower carry-in member 9, a driving roller 10, a driven roller 11, and a guide member 12, and transfers the transfer paper to the photosensitive drum 1 from between the upper carry-in portion 7 and the lower carry-in member 9. It is possible to supply for.

As shown also in FIG. 1, the transfer charger 13 and the separation neutralizer 17 include a discharge electrode wires 15 and 19 in a casing A having an upper opening and two chambers. Fixed through 32. Transfer charger
Openings 16 and 20 are respectively formed in a part of the bottom wall of the casing A forming the 13 and the separation static eliminator 17, and ozone generated by corona discharge of the discharge electrode wires 15 and 19 is supplied with the openings 16 and 20. It discharges from 20 to the outside of the casing. A large number of guide members 18 are arranged obliquely to the paper transport direction at the upper opening of the separation neutralization device 17 to prevent transfer paper from entering the casing A.

A large number of locking pieces 14 are attached to the opening 16 formed at the bottom of the transfer charger 13 at intervals. The mounting piece 14
Is formed of an insulating material such as a synthetic resin to prevent fluctuations in discharge characteristics. The mounting piece 14 may be made of a material made of an activated carbon sheet that absorbs ozone or a neutralizing agent that chemically changes nitrogen oxides, in addition to the synthetic resin.

Next, another embodiment of the present invention will be described with reference to FIGS. Note that the same components as those in the embodiment of FIG.

The present embodiment is characterized in that a suction duct 33 is provided below the casing A in which the transfer charger 13 and the separation neutralizer 17 are formed. On the upper surface of the suction duct 33, a suction port 36 is formed so as to face the opening 20 formed at the bottom of the separation static eliminator 17, and the opening 16 formed at the bottom of the transfer charger 13 is formed. And a plurality of locking portions 34 and suction ports
35 is formed. In addition, a suction hole is provided in the side wall of the suction duct 33.
37 is formed and connected to an existing fan (not shown) by a suction tube 39. Ozone generated by the corona discharge of the discharge electrode wires 15 and 19 is discharged from the openings 16 and 20 of the casing A to the outside through the suction duct 33 and the suction pipe 39.

The operation of the image forming apparatus having the above-described configuration will be described. The photosensitive drum is uniformly charged by corona discharge in the dark state by the charger 2, and the original image is projected as a mirror image on the photosensitive drum to obtain a bright and dark image. The surface image is attenuated in accordance with the light image to convert the light image into an electrostatic latent image, and the developing device 5 attaches toner charged to the opposite polarity to the charge of the electrostatic latent image to convert the toner image into a toner image. The transfer paper conveyed at the same speed as the peripheral speed of the photosensitive drum 1 is superimposed on the toner image in the device 6, and an electric field for moving the toner image to the back of the paper is given by the transfer charger 13. The transfer paper is separated from the photosensitive drum by 17, sent to a fixing device (not shown) by a paper transport device 21, and the toner image on the transfer paper is fused and fixed to the paper by heating or the like, and the toner remaining on the photosensitive drum 1 after transfer and separation is removed. Cleaning device 26 So that remove.

If the transfer paper does not separate from the photosensitive drum 1 and, for example, the leading edge of the transfer paper catches on the paper peeling claw 25 and causes a jam, the transfer paper bends and enters the casing A of the transfer charger 13, and When the transfer paper tries to penetrate through the ozone discharge opening 16 provided at the bottom of the A, the transfer paper is locked by the locking piece 14 attached to the opening 16 shown in FIGS. Opening 16 shown in FIG.
The discharge electrode wire 15 is prevented from being cut because it is stopped by the suction duct locking portion 34 provided at the lower part of the wire.

[Effects of the Invention] As described above, in the present invention, a casing is provided around the photosensitive drum, and an opening is formed in a part of the upper and lower bottom walls, and the casing is stretched inside the casing. A discharge electrode wire, and a plurality of locking pieces made of an insulating material attached so as to straddle the opening outside the bottom wall of the casing, or a suction member disposed below the opening. Since the duct has a plurality of locking portions and suction ports formed on the upper surface of the suction duct so as to face the opening, if the transfer paper does not separate from the photosensitive drum and jams, the transfer paper is When it bends into the casing of the transfer charger and tries to penetrate through the ozone discharge opening provided at the bottom of the casing, the transfer paper is attached to the locking piece attached to the opening or the lower part of the opening. Established Since it is stopped by the locking portion of the suction duct, cutting of the discharge electrode wire is prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a transfer device in the image forming apparatus of the present invention, FIG. 2 is a general configuration diagram of the image forming apparatus according to the present invention, and FIG. FIG. 4 is a cross-sectional view showing another embodiment of the apparatus, and FIG. 4 is a partial perspective view of FIG. 1 ... photosensitive drum, A ... casing, 14 ... locking piece,
15 wire for discharge electrode, 16 opening, 33 suction duct, 34 locking part, 35 suction hole.

Claims (3)

(57) [Claims] 1. A casing disposed around a photosensitive drum and having openings in a part of upper and lower bottom walls, a discharge electrode wire stretched in the casing, and a bottom of the casing. A transfer device in an image forming apparatus, comprising: a plurality of locking pieces made of an insulating material and attached so as to straddle an opening outside a wall. 2. The transfer device according to claim 1, wherein the insulating material is a material made of a synthetic resin, an activated carbon sheet, or a neutralizing agent that chemically changes nitrogen oxides. 3. A casing disposed around the photosensitive drum and having openings at upper and lower portions, a wire for a discharge electrode stretched in the casing, and disposed at an opening at a lower portion of the casing. A transfer duct in the image forming apparatus, comprising: a suction duct to be formed; and a plurality of locking portions and suction ports formed on the upper surface of the suction duct so as to face the opening.