JPS60119577A - Ozone removing method - Google Patents

Abstract

PURPOSE:To remove generated ozone from a transfer and a separation part immediately and prevent the disorder of an image due to the ozone by utilizing the attracting device of a transfer paper conveying device to attract and removing the ozone generated by the transfer part and separation part. CONSTITUTION:An electrostatic latent image is made visible with toner to form a toner image T. The toner image T formed on a photosensitive drum 1 is transferred to transfer paper P at a transfer part by the corona discharging of an electrostatic charger 3. The transfer paper P is separated from the drum 1 and sent in the conveying device by the corona discharging of a separating corona charger 4. A large amount of ozone is generated according to the operations of the transfer and separating corona chargers 3 and 4. The generated ozone is attracted and discharged by the attracting device 6 of the conveying device 5 through a coupling member 7. Consequently, the image disorder, i.e. drowsy look due to the ozone is prevented and a copy of good image quality is obtained from the 1st sheet at the start of copying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an ozone removal method for an electrophotographic copying machine that uses corona discharge to transfer a toner image and separate a transfer paper.

[Prior art]

In general, in a Seiko photocopier, a photoreceptor drum with a photoconductive substance on its surface is charged, exposed to phototherapy to form an electrostatic latent image, and the electrostatic latent image is transferred to the toner. After being visualized by the toner image, this toner image is transferred to a transfer paper in a transfer section. As this transfer means, a means is used in which a transfer paper is brought into contact with a photoreceptor drum, and a corona discharge of opposite polarity to the toner is generated from the back side of the transfer paper to transfer the toner image from the drum to the transfer paper. . However, after this transfer process, an electrostatic attraction force acts between the drum surface and the transfer paper, especially in the parts of the drum surface where toner is not adsorbed, making it difficult to separate the transfer paper from the drum surface. Become. For this reason, in general, in the separation section, a separation corona charger is provided separately from the transfer corona charger in order to leak the charge generated on the transfer paper during transfer, and this is connected to an AC biased by a DC bias voltage. Apply voltage and
Corona discharge is applied from the back side of the transfer paper.

However, when a corona charger is used during transfer and separation, a large amount of ozone is generated in the transfer and separation sections, and this ozone oxidizes nitrogen in the air to form nitrogen oxides. This nitrogen oxide further reacts with moisture in the air to become nitric acid or nitrous acid, which adheres to the surface of the photoreceptor drum. When nitric acid or nitrous acid, which is a water-soluble substance, adheres to the surface of the photoreceptor, the surface of the photoreceptor becomes low in resistance, its charge retention ability decreases, and image distortion occurs.

This tendency for image disturbance to occur is more pronounced when the copying machine is turned off after copying is completed and left for a long period of time in a humid environment. In actual use, this image disturbance may occur after copying is completed, when the power is turned off and left unattended, and when the power is turned on the next morning and copying is started, several or even dozens of images may be blurred in the morning. This appears as a blurring phenomenon called.

In order to prevent this image distortion, conventional methods of removing ozone, which is the cause of the generation, have been to cut out a part of the corona charger for transfer or separation to prevent the generated ozone from accumulating, or to prevent ozone from accumulating in the corona charger. Attempts have been made to coat the inside of the shield of the vessel with manganese dioxide to adsorb ozone, but none of these methods were sufficiently effective in removing ozone. It has also been proposed to provide a separate suction device to remove ozone by suction, but this not only increases costs but is also very inconvenient in terms of miniaturizing the copying machine.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently removing ozone generated in a transfer and separation corona charger of a copying machine at low cost and without causing any hindrance to miniaturization of copying machines. .

[Summary of the invention]

In the present invention, the ozone generated in the transfer and separation corona charger is removed by suction using the suction device of the transfer paper conveying device disposed downstream of the transfer and separation section, and a separate ozone suction device is installed. The purpose is to efficiently remove generated ozone at low cost and prevent image disturbances caused by ozone.

[Embodiments of the invention]

Next, the present invention will be described based on drawings showing an example of the configuration of an ozone removal device used for carrying out the present invention.

In the drawing, ■ is a photosensitive drum, 2 is a paper guide that guides the transfer paper P to the transfer section where the transfer corona charger 3 is arranged,
4 is a separation corona charger provided adjacent to the transfer corona charger 3; 5 is a belt for conveying the transfer paper P separated by the separation corona charger 4 toward a fixing device (not shown); A type transfer paper conveyance device 6 is a suction device provided in the conveyance device to attract and convey the transfer paper P.

Reference numeral 7 denotes a connecting member that connects the notches 3' and 4' of each shield of the transfer corona charger 3 and the separation corona charger 4 to the suction device 6.

To explain the operation of the ozone removal apparatus configured as described above, first, the photosensitive drum 1, which is rotated in the direction of the arrow, is charged and exposed to form an electrostatic latent image. The electrostatic latent image is then visualized with toner to form a toner image T. On the other hand, the transfer paper P is guided by the paper guide 2 and carried into the transfer section at a speed equal to the circumferential speed of the photoreceptor drum 1p.

Then, in the transfer section, the toner image T is superimposed on the toner @T formed on the photoreceptor drum 1, and the toner image T is transferred onto the transfer paper P by corona discharge from the transfer corona charger 3. The transfer paper P onto which the toner @T has been transferred is then separated from the photosensitive drum 1 by corona discharge from the separation corona charger 4 and sent to the transfer paper conveying device 5 . The sheet is then attracted by the belt of the transfer sheet conveyance device 5 and conveyed toward a fixing device (not shown).

At this time, a large amount of ozone is generated due to the operation of the transfer and separation corona charger 3.4. In the present invention, the generated ozone is sucked into the suction device 6 of the transfer paper conveying device 5 via the connecting member 7 and discharged to the outside.

In this way, the ozone generated by the transfer and the corona discharge of the separation corona charger 3.4 is immediately and efficiently discharged outside the machine without staying in the transfer section and the separation section.
There is no adverse effect on the photoreceptor drum 1. Therefore, image disturbance caused by ozone, so-called morning blur, can be prevented, and when copying is started, copies with good image quality can be obtained from the first copy.

In the configuration example of the ozone removal device described above, the connecting member connected between the transfer and separation corona charger and the suction device is as follows:
Appropriate means can be used, and an ozone filter can be attached to the outlet of the suction device, if necessary.

〔Effect of the invention〕

As explained above, the present invention utilizes the suction device of the transfer paper conveyance device to suction and eliminate ozone generated in the transfer section and the separation section. Therefore, image disturbances caused by ozone can be prevented. Further, since a separate suction means is not provided to remove ozone by suction, ozone can be effectively removed without any hindrance to miniaturization and cost reduction of copying machines.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing an example of the configuration of an ozone removal apparatus used for carrying out the ozone removal method of the present invention. ■...Photosensitive drum, 3...Transfer corona charger, 4...Separation corona charger, 5
......Transfer paper conveyance device, 6...
Suction device, 7...Connection member 0

Claims (1)

[Claims] a photoreceptor that forms a toner image on its surface and moves in one direction;
A transfer corona charger for transferring the toner image onto a transfer paper, a separation corona charger for separating the transfer paper from the photoreceptor after transfer, and a suction device for conveying the separated transfer paper to a fixing device. In an electrophotographic copying machine equipped with a transfer paper conveyance device, an ozone removal method characterized in that ozone generated in the transfer corona charger and the separation corona charger is suctioned and removed by a suction device of the conveyance device. .