JPS6015660A - Developing device - Google Patents

Abstract

PURPOSE:To prevent squeeze-out of a magnetic developer with a projecting part formed with a notched part of a side plate by inserting the end part of a sleeve to the notched part of the side plate. CONSTITUTION:Squeeze-out of the magnetic developer occurs when the developer is carried to a developing region after the developer carried by rotation of a sleeve 5 has the thickness controlled by a doctor member 9. A part of a side plate 12 of a tank which supports a developing roll 4 is notched, and the end part of the sleeve 5 is inserted to this notched part 13. Through the developer has the thickness controlled by rotation of the sleeve 5 in the direction of an arrow B and is carried to the developing region and is affected by a magnetic pole N of a permanent magnet 8 to move on the sleeve 5 toward the plate 12, the developer is prevented from getting out to the outside of the plate 12 by a projecting part 14 of the notched part 13 because the end part of the sleeve 5 is inserted to the notched part 13, and thus, squeeze-out of the developer is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device, and particularly to a magnetic brush type developing device that develops an electrostatic latent image using a magnetic developer.

In the magnetic brush development method, developer powder containing a magnetic substance contained in a developer container is attracted by a magnet roll and conveyed to a development area.

The image carrier material placed in close proximity to the magnet wheel is, as is well known, a layer of high-resistivity polyester sheet, photoconductive selenium, and photoconductive cadmium sulfide dispersed in an insulating binder. It is composed of an insulating film covering the surface, an organic photoconductor such as polyvinylcarbazole or poly-N-vinylcarbazole, and a layer consisting of an insulating resin binder in which photo-SN zinc oxide is dispersed.

Developer powder is fed from a developer container onto a magnetic roll through a gap of predetermined size and then conveyed along the magnetic roll to a development area by rotation of the magnetic roll. At least in the development area, the developer powder is
By forming a magnetic brush on the magnetic roll and rubbing the surface of the image carrier material with the magnetic brush, the toner material in the developer adheres to the electrical pattern image on the surface of the carrier.

In the present invention, the electrical pattern image refers to an electrostatic pattern.

It includes a capacitor pattern and a conductive pattern, but in the following explanation, is it static electricity? Use Ilfg+.

In the magnetic brush development described above, a mixture of ferromagnetic carrier particles and toner particles has conventionally been used as a developer. This magnetic carrier may be made of, for example, iron or steel9. The surface of a core made of nickel, ferrite, etc. is coated with a resin, and the toner is made of particles in which additives such as coloring pigments and dyes are dispersed in a binder resin.

By mixing the carrier particles and toner particles, they are triboelectrically charged to have opposite magnetic properties. In normal development, the materials of the carrier particles and toner particles are selected so as to impart to the toner particles a charge of opposite polarity to that of the electrostatic latent image on the image carrier.

A developer mixture (hereinafter referred to as magnetic developer) is stored in a developer container in a state in which toner particles are attached to the surface of carrier particles by triboelectric charging, and then conveyed over the surface by rotation of a magnetic roll. The magnetic developer forms a magnetic brush in the development area, and by rubbing the latent image with this magnetic brush, the toner particles are
Adheres to the latent image. After development, the magnetic developer that has consumed toner is collected into a developer container, and then fresh toner is replenished.

In order to prevent the developer from spilling out from the developing device, protrusions are conventionally provided at both ends of the doctor member that regulates the magnetic visual image agent supplied to the developing area by the magnet roll. Although felt was used on the back side, ``it had the disadvantage that it did not provide sufficient protection.

An object of the present invention is to provide a developing device which can reliably prevent the developer from spilling out from the developing device, since the above-mentioned drawbacks have been solved.

The structure of the present invention is such that a developing magnet roll, in which a permanent magnet member having a plurality of magnetic poles is provided in a cylindrical rotating sleeve made of a non-magnetic material, faces a photoreceptor drum and forms a developing gap. a developer container for supplying magnetic developer to the developing magnet roll; a doctor member for regulating the amount of magnetic developer supplied to the developer gap; In a developing device having a scraper member for scraping off magnetic developer, a side plate supporting the developing magnet roll is provided with a notch on a surface facing the roll, and both ends of the sleeve are inserted into the developing device. .

Embodiments of the present invention will be described below based on the drawings.

Here, FIG. 1 is a sectional view of a developing device according to an embodiment,
FIG. 2 is an enlarged perspective view of the main part of FIG. 1.

In the figure, 1 is a developer tank, which is a developer container, and 2 is a two-component magnetic developer containing a ferromagnetic carrier and toner, which is housed in the developer tank 1. 3 is a photosensitive drum; 4 is a developing magnet roll (hereinafter referred to as a developing roll) disposed in the developer tank 1 facing the photosensitive drum '3, forming a developing area A between it and the photosensitive drum 3; do. 5 is a non-magnetic material r1
The cylindrical sleeve 6 is a permanent magnet member provided within the sleeve 5, and the sleeve 5 and the permanent magnet member 6 constitute the developing roll 4.

The permanent magnet member 6 includes a shaft 7 and a cylindrical permanent magnet 8 having a plurality of eleven poles on the surface fixed around the shaft. Reference numeral 9 represents a doctor member having a length substantially equal to the length of the permanent magnet 8, and reference numeral 10 represents a scraper member.

In the above configuration, the magnetic developer 2 adsorbed on the surface of the developing roll 4 is conveyed in the same direction by rotating the sleeve 5 in the direction of arrow B, and its thickness is regulated by the doctor member 9. After that, it is transported to the development area A. In the development area A, the magnetic developer 2 forms a magnetic brush, and by rubbing the surface of the photoreceptor drum 3 with this magnetic brush, the toner in the magnetic developer forms an electrostatic latent image (not shown). ). The magnetic developer 2 after passing through the development area A is scraped off from the top of the sleeve 5 by the scraper member 10. Reference numeral 11 denotes a conveying magnet roll, which conveys the magnetic developer 2 to the developing roll 4.

In this developing device, the protrusion of the magnetic developer 2 occurs when the magnetic developer 2 transported by the rotation of the sleeve 5 is transported to the development area A after its thickness is regulated by the doctor member 9. However, as shown in the enlarged perspective view of main parts in FIG. A part of the surface of the notch 13 is cut out.
The end of the sleeve 5 is inserted into the sleeve.

Therefore, the thickness of the magnetic developer 2 is regulated by the rotation of the sleeve 5 in the direction of arrow B, and the magnetic developer 2 is conveyed to the development area A.
Even if the magnetic developer 2 moves on the sleeve 5 in the direction of the side plate 12 under the influence of the magnetic pole N of the permanent magnet 8, the end of the sleeve 5 is inserted into the notch 13, so the magnetic developer 2 does not flow into the notch. 1
3 of the side plate 12 prevents the developer from escaping to the outside of the side plate 12, thereby preventing the developer from spilling out.

As explained above, in the developing device according to the present embodiment, a part of the surface of the side plate 12 of the developer tank 1 supporting the developer roll 4 on the side facing 1' to the developer roll 4 is cut out to form a cutout portion 13. , and the end of the sleeve 5 is inserted into the notch 13. Therefore, the developer 2 protrudes from the notch 13.
The protrusion 14 of the side plate 12 formed by
As stated above, the present invention is an invention that can be expected to provide a developing device that can prevent developer from spilling out, and has excellent practical effects. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a developing device according to an embodiment of the present invention;
FIG. 2 is an enlarged perspective view of the first hair part. 1...Developer tank, 2...Magnetic developer, 3...
Photosensitive drum, 4... Magnet roll for development, 5.
... Sleeve, 6... Permanent magnet member, 8... Permanent magnet, 9 River doctor member, 12... Side plate, 13... Notch.

Claims (1)

[Claims] A developing magnet roll, in which a permanent magnet member having a plurality of magnetic poles is provided in a cylindrical rotating sleeve made of a non-magnetic material, is installed facing the photoreceptor drum and forming a developing gap. a developer container for supplying magnetic developer to the magnetic roll for use, a doctor member for regulating the amount of magnetic developer supplied to the developer gap, and a blade member for scraping off the magnetic developer after passing through the development gap. 1. A developing device having a scraper member, wherein a notch is provided in a side plate that supports the developing magnet roll and faces the roll, and both ends of the sleeve are inserted into the side plate.