JPS608870A - Transfer preprocessor of electronic copying machine - Google Patents

Abstract

PURPOSE:To improve transfer efficiency and prevent a form from being stained by providing a transfer pre-exposure lamp which exposes the internal surface of a photosensitive body from inside of the photosensitive body right in front of the transfer area of a transfer corotron which transfers a toner image formed on the surface of the photosensitive body. CONSTITUTION:A support plate 13 is provided in the transfer area wherein the toner image formed on the surface of the photosensitive body 1 is transferred in a developing process, and a transfer pre-exposure lamp 14 is provided over its light transmission part 13a to expose the photosensitive body 1 from inside of the photosensitive body 1. The toner image developed by a developing device 4 is held at a high potential until it reaches the transfer area of the transfer corotron 6, so part of toner is never absent from the toner image in the middle, so that neither a decrease in transfer efficiency nor the staining of the form with scattering toner is caused.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a transfer pretreatment device 6 for an electronic copying machine using a belt-shaped photoreceptor.

Prior Art Conventionally, in this type of copying machine, in order to avoid transfer efficiency, the first
As shown in the figure, a pre-transfer exposure lamp b is placed on the exit side of the developing device a.
The image potential of the photoreceptor C is lowered as shown in FIG. 2 by irradiating the photoreceptor C with the exposure lamp b.

However, in the above-mentioned transfer pretreatment device, the exposure lamp b
The toner image must be conveyed a long distance to the transfer corotron d while being held by weak electrostatic adhesion force with a lower image potential.

During this time, vibrations of the photoreceptor C and airflow inside the copying machine body occur.

Under the influence of electrostatic adsorption force caused by conductive parts such as the guide plate e installed in the paper transport path, some of the toner is missing from the toner image and adheres to the guide plate e, etc., causing paper stains. This results in a decrease in transfer efficiency.

Furthermore, in the conventional method in which the photoconductor C is exposed to light from the toner-attached surface side of the photoconductor C, the photoconductor C, which is almost uniformly charged as shown in FIG. For halftones, low resolution areas and solid areas! 5) Due to the variation in the thickness of the first layer,
As shown in FIG. 3(B), the charging of the photoreceptor C before and after exposure before transfer is non-uniform, which causes a fringe electric field to be generated in the toner image.

In other words, lines of electric force are generated inside the toner image from the high potential area (VG',) to the low potential area (FG;'), and 16
Parts of the toner image in the potential area (VG, ') that are less sensitive are scattered into the copying machine body due to vibrations of the photoconductor C, so white dots may appear in halftone areas and solid black areas after transfer. There were problems such as omissions and uneven transfer electric potential.

Purpose of the Invention The present invention has been made to improve the above-mentioned problems, and provides a transfer pre-processing device for an electronic copying machine that performs transfer pre-processing from the inside of the photoreceptor immediately before the transfer area, thereby improving transfer efficiency. and improvement of.

This is intended to prevent white dots from appearing on the transferred image and from staining the paper with scattered toner.

Structure of the Invention Immediately before the transfer area of a transfer corotron that transfers a toner image (formed on the surface of a photoreceptor to paper), a pre-transfer exposure lamp that exposes the inner surface of the photoreceptor is installed, A pre-transfer processing device for electronic copying machines designed to improve transfer efficiency.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings shown in FIG. 4 and below.

In the figure, reference numeral 1 denotes a belt-shaped photoreceptor having translucent properties, and a charged corotron 2. Inter-image static elimination lamp 3, developing device 4. Paper transport means 5. Transfer roller Iron 6
and static elimination corotron 7, paper conveyance means 8. Static elimination corotron9. The cleaning device 10 and the static elimination lamp 11 are arranged in the above order along the rotation direction (arrow) of the photoreceptor 1. In addition, the toner image formed on the surface of the photoconductor l in the developing process is transferred to the paper 1 conveyed by the paper conveyance means 8.
A support plate 13 is provided inside the photoconductor cage in the transfer area where the toner image is transferred to the photoconductor 1. The support plate 13 supports the inside of the photoconductor 1 before transferring the toner image, In addition to preventing the body 1 from vibrating irregularly, the support plate 13
A light-transmitting portion 13α such as a slit is provided at. A pre-transfer exposure lamp 14 is installed above the upper dpi light transmitting section 13a.1. The Y7 body 1, which is sensitive to the light irradiated from the light-transmitting portion 13α toward the inner surface of the photoreceptor 1, can be exposed from the inside. Further, a light shielding plate 16 is provided between each end of the supporting plate 13 and the supporting plate 15 installed below the cleaning device 10, and a light shielding plate 16 is provided between the supporting plate 13 and each end of the supporting plate 15 installed below the cleaning device 10. By introducing light between the static eliminating corotron 9 and the cleaning device 1O and exposing the photoreceptor 1 from the inside of the photoreceptor 1, the pre-transfer exposure lamp 14 doubles as a static eliminating lamp. Light shielding plate 1
6 prevents the light from the pre-transfer exposure lamp 14 from leaking to the developing device 4 side.

Effects of the Invention As described in detail above, the present invention is characterized in that the pre-transfer exposure lamp 14 is provided in the transfer area to expose the photoreceptor 1 from the inside of the photoreceptor 10.

Since the toner image developed by the developing device 4 is held at a high potential as shown in FIG. 5(a) until it reaches the transfer area, no part of the toner is lost from the toner image on the way. This eliminates the risk of the transfer efficiency being reduced or the paper being soiled (by scattered toner), and by exposing the inside of the photoreceptor 1, the toner is not affected by variations in the thickness of the toner layer. Since a uniform potential (see FIG. 5(b)) is obtained, the problem of missing white spots in halftone parts and solid black parts of the transferred image is also eliminated. Furthermore, if the pre-transfer exposure lamp 14 is used to simultaneously expose the photoreceptor 1 before cleaning, the photoreceptor 1 can be neutralized as shown in FIG. This also makes it possible to reduce the size and cost of the device.

The light intensity of the pre-transfer exposure lamp 14 can be adjusted using the transparent section +31.
Install an optical filter in 2 to adjust the amount of transmitted light, or in the case of a slit, adjust the width of the slit i! ! Alternatively, the distance from the pre-transfer exposure lamp 14 to the photoreceptor 1 or the applied voltage may be changed.

[Brief explanation of the drawing]

FIG. 1 is a diagram F3A of a conventional transfer pre-processing device, and FIGS. 2 and 3 (A) and (B) are before transfer pre-processing is performed. 4 is a diagram showing the potential of the photoreceptor after being transferred, FIG. 4 is a block diagram of a transfer pretreatment device showing an embodiment of the present invention, and FIGS. FIG. 6 is a diagram showing the potential of the photoreceptor before and after the treatment, and FIG. 6 is a diagram showing the potential of the photoreceptor after the static elimination treatment before cleaning. 1 photoreceptor, 5 a paper transport means, 6 a transfer corotron,
12 is paper, 14 is pre-transfer exposure lamp 0 Applicant Fuji Xerox Co., Ltd. Agent Patent attorney Masaaki Yonehara Patent attorney Tadashi Fuku 1 Figure 2 Figure 3 Figure 5 Management!゛(A) (B) Figure 6

Claims (1)

[Claims] A sheet of paper I2 on which a toner image formed on the surface of a translucent belt-shaped photoreceptor 1 is conveyed by the sheet conveying means 5.
Pre-transfer processing of an electronic copying machine, which is provided with a pre-transfer exposure lamp 14 located inside the photoreceptor 1 and exposing the inside of the photoreceptor 1 immediately before the transfer area of the transfer corotron 6 for transferring images. Device.