JPS58137871A - Cleaning device for electrostatic recording device - Google Patents

Abstract

PURPOSE:To obtain a brush cleaning device for a one-compnent magnetic toner which can be applied to high-speed copy and has a high cleaning effect, by using a magnetic brush, an electrode, etc. to utilize magnetic and electric attractions. CONSTITUTION:An excess one-component magnetic toner of a recording drum 1 is swept off by a magnetic brush which is formed by a sleeve 4, a magnetic roller 2, etc. consisting of magnetic particles. The one-component magnetic toner in the magnetic brush is attracted to a toner recovering electrode 5 by the electric field generated by the electrode 5 and is recovered through a scraping member 8 or the like. By this constitution where the magnetic attraction due to the magnetic brush is not used for development but is used exclusively for cleaning, and the electric attraction due to the electrode is used, and brush cleaning device for the one-component magnetic toner which can be applied to high-speed copy and has a high cleaning effect is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides cleaning methods for electrostatic recording devices such as electrophotographic copying machines. In particular, the present invention relates to an improvement in a cleaning device for an electrostatic recording device that performs development using component-based magnetic toner.

Conventionally, as a cleaning device for an electrostatic recording device that performs development using -component magnetic toner, there is a developing/cleaning device that performs magnetic brush development and cleaning in the same device, and a magnetic cleaning device that uses only -component magnetic toner. A brush cleaning device was used. As a cleaning method that does not utilize magnetism for other-component magnetic toners, the well-known fur brush cleaning method and blade cleaning method are used.

However, in the case where a developing/cleaning device is used, the photosensitive drum rotates twice to obtain one copy, so it is not suitable for high-speed copying. In addition, in the case of a magnetic brush cleaning device made only of negative-component magnetic toner, the magnetic toner's magnetism is not so strong, so no significant cleaning effect can be expected, and in some cases, the magnetic toner may re-adhere to the surface of the photoreceptor. can also occur.

Further, other cleaning devices do not utilize the magnetism of magnetic toner but utilize mechanical sliding force, which is undesirable because they damage the photoreceptor or generate noise.

An object of the present invention is to provide a brush cleaning device which eliminates the above-mentioned drawbacks of conventional cleaning devices and is applicable to high-speed copying and has a high cleaning effect. a magnetic roller means for adsorbing to form a magnetic brush and removing the component-based magnetic toner remaining on the recording medium; an electrode for electrically collecting the toner attracted to the magnetic particles; This is achieved by a cleaning device in an electrostatographic copying machine that includes means for removing the adsorbed toner and collecting means for collecting the removed toner.

The present invention will be described in detail below using the drawings.

FIG. 1 is a schematic structural diagram of an embodiment of the magnetic brush cleaning device of the present invention. In the figure, reference numeral 1 denotes a recording drum rotating in a clockwise direction, and an image of magnetic toner is y! It has been made. When the recording medium 11Lffi photoconductor is used, the photoconductor is statically neutralized using static eliminating light 10 before the cleaning section a.

Next, when the toner image comes to a position facing the magnetic brush formed by the magnetic roller 2 and the magnetic particles 3, it is attracted by the magnetic particles 3 and carried into the cleaning section C. In the cleaning section O, the magnetic particles 3 are transferred to the sleeve 4 by the rotation of the non-magnetic sleeve 4 rotating outside the magnetic roller 2.
The magnetic grains 3 are conveyed clockwise along the top, but before conveyance, the layer thickness of the magnetic grains 3 is first adjusted by the ear stand regulating member 7 for cutting the ears. The surface of the sleeve 4 may be roughened by sandblasting, metal spraying, etc. to improve conveyance.

The magnetic particles 3 with a uniform layer thickness are conveyed by the rotation of the sleeve 4 and reach a toner collection electrode 5 provided at a position facing the magnetic roller 2. A pressure having a polarity opposite to the charged potential of the toner is applied to the electrode 5 by a power source 9 for collecting toner, and the toner is removed by the electric field between it and the non-magnetic sleeve 4 of the magnetic roller 2. is attracted to.

The toner that has been removed to the eye side is collected in the toner collecting section 6 by the scraping member 8. The collected toner is fixed to the bottom surface of the cleaning section by the collecting magnet 12, so that the collected toner does not scatter.

The magnetic toner is recovered through the following steps.

The method of using the magnetic granules according to the present invention is that in addition to the ear sweeping force generated by the magnetic field and the electrostatic force, the magnetic field is concentrated at the tip of the magnetic granules, so there is a strong magnetic attraction force toward the magnetic toner. It showed an extremely good leaning effect.

It is clear from the above-mentioned reasons that it is necessary to select a material with high magnetic permeability for the magnetic particles used here. In addition, in order to increase the surface area per unit volume of the magnetic particles and improve the toner adhesion retention, it is necessary to reduce the particle size to 10 μmN.
Those in range H of 100 μm are better. Experimentally 3
The one with a diameter of about 0AWLφ had the best effect in terms of conveyance.

When cleaning a conductive sinner, since the toner itself has lost its charge, an attraction force due to electrostatic force cannot be expected, but charge injection into the toner is likely to occur in order to promote adhesion to the toner collection electrode 5. Thus, better results were obtained by using magnetic particles whose volume resistivity was lower than that of the toner.

Since the electric field can be strengthened even in the case of insulating toner, it is preferable to use one with low volume resistance. In response to these requirements, the use of ferrite particles has the following advantages: high magnetic permeability, a constant resistance value, little change over time, and a constant particle size. , showed stable cleaning performance.

On the other hand, for insulating toner, we used magnetic particles coated with a resin that is charged with the opposite polarity to the toner.
It has been found that the strong attraction force due to magnetic force and electrostatic force is excellent in the cleaning effect.

In FIG. 1, the magnetic field produced by the magnetic four-wheeler 2 forms a repelling magnetic field at the portion where the toner is attached to the toner collecting electrode 5 from the magnetic particles, which is effective in collecting the toner.

Note that if the applied voltage of the cleaning power source lO applied to the magnetic roller 2 is VtO, and the applied voltage of the collection power source 9 applied to the toner collection electrode 5 is v9, then in the case of toner charged to ■, V9<Via≦. 0, and in the case of toner charged to ■, it is appropriate to set 0≦v1o (ve).

As described above, according to the present invention, when cleaning the -component magnetic toner, cleaning is performed using magnetic and electrostatic attraction forces and a magnetic brush made of magnetic particles, so that efficient cleaning can be performed. This makes it a cleaning device that can also be used for high-speed copying.

Furthermore, according to the present invention, since the magnetic toner is removed from the magnetic particles electrostatically, the device can be made smaller and has excellent effects such as eliminating noise and toner scattering problems. be.

[Brief explanation of the drawing]

No. tg is a schematic structural diagram of an embodiment of the present invention. 0 1...Recording body drum 1a... Recording body 21. ...Magnetic ring 3...Magnetic grains 4...Sleeve 5...Toner collection electrode 6...Toner collection section 7...・
... Ear standing regulation part 8 ... Scraping plate 9
...... Power supply for collection lO... Power supply for cleaning 11... Static elimination light 12... Collection magnet representative Hanito Yoshimi Kuwabara

Claims (4)

[Claims] (1) A magnetic brush is formed by magnetically layering magnetic grains, and a magnetic brush is used to remove the magnetic toner remaining on the recording medium. A cleaning device for an electrostatic recording device, comprising an electrode for picking up a target, a means for removing toner adsorbed to the electrode, and a collecting means for collecting the removed toner. (2) A cleaning device 0 for an electrostatic recording device according to claim 1, wherein the magnetic particles are made of 7-magnetic light particles with particle diameters ranging from 10 to 100.
゛ (3) The electrostatic device according to claim 1 or 2, characterized in that the magnetic particles are coated with a resin that is charged with a polarity opposite to that of the toner due to friction with the recording medium. A cleaning device in a recording device. (4) Claim l! characterized in that the magnet body in the magnetic pusher has a repulsive magnetic field where the magnetic brush and the electrode face each other! I Items 1 to 3 XJ Recordings in Electrostatic Recording Devices at.