JPS631586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for recovering only normal residual developer, cleaning liquid, etc. flowing out from a photoreceptor to a developing section in a transfer type electrophotographic apparatus.

Wet or dry type developer remaining on the photoconductor without being transferred to the transfer paper is removed from the surface of the photoconductor in the cleaning section, and in the wet type, it is guided to the developing section along with the cleaning liquid by the collection gutter. Offered for reuse.

To explain this in more detail using an example in which selenium is used in the photoreceptor, the static electricity is removed by a static eliminator, then uniformly positively charged by a charger, and then the image pattern is Once an electrostatic latent image is obtained, this latent image is usually developed with a toner of negative polarity.
Further, this image is transferred to transfer paper by a transfer charger.

However, since the charging here is of positive polarity, the polarity of a portion of the toner remaining on the surface of the photoreceptor without being transferred is reversed and becomes positive. When this is led to the developing section together with the cleaning liquid, it combines with normal negative toner in the developing section and condenses. If they are reused as they are, they will clog the tubes or pipes in the device, contaminate the developing device, etc., and even create black dots on the image, causing deterioration in image quality.

The present invention is intended to eliminate the above-mentioned problems. Among the developer remaining on the surface of the photoreceptor after transfer, the developer whose polarity is reversed is removed before being collected into the developing section, so that it can be restored to normal condition. It is an object of the present invention to provide a device that collects only the toner to a developing section.

Hereinafter, details of the present invention will be explained based on the drawings.

FIG. 1 shows an embodiment of the present invention applied to a wet-type electrophotographic apparatus in which the photoreceptor is a drum type. Reference numeral 1 denotes a photoreceptor drum, around which are a static eliminator 2, a charger 3, an exposure section 4, and a developing device. A container 5, a squeeze roller 6, a transfer charger 7, a static eliminator 8, a cleaning roller 9, a cleaning liquid supply pipe 10, and a cleaning blade 11 are arranged in order of process.

Reference numeral 12 denotes a collection gutter to which the present invention is applied, which is provided directly below the cleaning section on both sides of the photoreceptor drum 1, and is used to receive developer residual liquid, cleaning liquid, etc. flowing out from the photoreceptor, and collect it into the developing device 5. be.
Reference numeral 13 indicates a power source that applies voltage to the collection gutter 12.

FIG. 2 shows a cross section of the collection gutter 12, in which a voltage of the same polarity as the toner is applied to the conductor forming the gutter, and the upper counter electrode 12a is connected to the insulator 1.
They are integrally formed via 2b.

As mentioned above, most of the toner remaining on the surface of the photoreceptor without being transferred is negative polarity toner, but some of it is positively charged at the transfer area, so its polarity is reversed and becomes positive polarity. have. This residual toner is scraped off by a cleaning blade 11 while being supplied with cleaning liquid from the developing device 5, and flows into a collection gutter 12 to which a voltage of the same polarity as the toner, that is, a negative polarity, is applied. As a result, some toner that has reversed and now has positive polarity is drawn to the collection gutter 12 and adheres to its inner wall surface, but most of the toner that has normal negative polarity is removed from the collection gutter 12. It collects on the liquid surface part far from the inner wall and closest to the counter electrode 12a, flows down, and is guided into the developing device 5. The reversed toner adhering to the inner wall of the collection gutter 12 can be easily removed by changing the polarity of the applied voltage to positive when cleaning the gutter 12.

In the embodiment shown in FIG. 3, a collection gutter 12' is formed of an insulating material, a negative electrode 12c is disposed below it, and a positive electrode 12d is disposed above it to face each other, and the reversed toner is transferred to the collection gutter 12'. It is attached to the bottom.

In the embodiment shown in FIG. 4, the collection gutter 12'' to which a voltage of negative polarity is applied is made into a U-shaped release gutter to prevent normal negative toner from adhering to the counter electrode 12a. .

Although the photoreceptor shown in Figure 1 uses selenium, the material of the photoreceptor is not limited to this, and the same effect can be achieved with a belt instead of a drum. It can also be applied to positive polarity toner, such as in reversal development.

As described above, according to the present invention, a means is provided for applying a voltage of the same polarity as the toner to the bottom side of the recovery channel, and a means for applying a ground potential or a voltage of the opposite polarity to the toner to the top side, so that the resistance is reduced. The regular toner and reversed toner present in a large liquid are forcibly separated into the upper and lower sides of the collection channel during the flow process, and by collecting the reversed toner and recovering the regular toner, the toner in the developing section is separated. It is possible to prevent condensation, extend the service life of the developer, and greatly improve copy quality with this type of developing device.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an electrophotographic apparatus incorporating one embodiment of the present invention, and FIGS. 2 to 4 are sectional views of other embodiments. 5...Developer, 11...Cleaning blade, 12...Collection gutter, 13...Power supply, 12b...
Insulator.

Claims (1)

[Claims] 1. A recovery channel is provided between the cleaning section and the developing section, which transports the cleaning solution supplied from the developing section and the developer removed from the photoreceptor from the cleaning section to the developing section, and A voltage applying means is provided for applying a voltage having the same polarity as the toner to the bottom side of the recovery flow path, and applying a ground potential or a voltage having the opposite polarity to the toner to the upper side of the recovery flow path. Developer recovery device for electrophotographic equipment.