JPS6053973A - Non-magnetic one-component developing device - Google Patents

Abstract

PURPOSE:To enable application of specified electric charge to a developer constantly for a long period of time without impressing a high voltage to a regulating member by forming micro-recesses on the surface of a carrying body and embedding a charge control material added in the developer into the recesses. CONSTITUTION:A developer 1 which is a non-magnetic one-component type developer, is fed to a regulating member 4 by rotation of a carrying body 3 and is formed to a thin developer layer to be used for developing of an electrostatic latent image on a holding body 7. The charge control material 5 embedded in the recesses 3a on the surface of the body 3 and the developer 1 rub against each other in the sliding contact part between the member 4 and the body 3 and since the material 5 in the developer 1 is always supplied, the developer 1 is eventually electrified constant always by the fresh member 5. The specified charge is thus applied constantly to the developer 1 even if the device is used for a long period of time and the specified sharp image is always obtd. without generation of a photographic fog and thickening of the character image.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a non-magnetic one-component developer that develops an electrostatic latent image formed on a carrier into a visible image using a non-magnetic one-component developer in an electrophotographic apparatus. The present invention relates to a component developing device.

Prior art Utility Model Publication No. 53-30339, IRF Kaisho Kaiport No. 547
As disclosed in Japanese Patent Application No. 41, a regulating member is pressed against a carrier, and the developer supplied on the carrier is frictionally charged between the regulating member and the carrier to give an electric charge to the developer. A non-magnetic component developing device is known in which a thin developer layer of a required thickness is formed, and this developer rK layer is sent to a holder and allowed to adhere to the electrostatic latent image, thereby developing it into a visible image. It is being

In this developing device, charging the developer (
In other words, if the charge level of the developer is N, the regulating member is selected in consideration of the electrification series, and the developer is frictionally charged between the regulating member and the carrier.

However, if the above structure is used for a long period of time, the developer composition will be filmed on the surface of the υ regulating member, the charging effect will be lost, and the developer will not be able to be charged.

If the developer is no longer charged, the image of a single character with fog will become thicker, making it impossible to obtain a good image.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. Shosa-+5g937, by applying a high voltage to the regulating member and injecting the charge into the developer, it is possible to reliably apply the charge to the developer. What has been done is known.

However, this configuration requires a high voltage source and is expensive, and also causes various problems due to leakage to the carrier.

OBJECTS OF THE INVENTION It is an object of the invention to always provide a constant charge to a developer over a long period of time without applying a high voltage to a regulating member.

A component of the invention in which minute recesses are formed on the surface of the carrier, and a charge control material added to the developer is embedded in the recesses.

Embodiment FIG. 1 is an overall explanatory view of a non-magnetic component developing device, in which a supporting member 3 is rotatably provided at the bottom of a hopper 2 in which a developer 1 is stored, and a regulating member 4 is fixed to the hopper 2. is in contact with the carrier 3 under a predetermined pressure.

Four minute portions 3α are formed on the surface of the carrier 3, and a charge control material 5 is embedded in this recess 3a.
A holder 7 facing the carrier 3 and holding an electrostatic latent image 6 is rotatably provided.

g is a bias power supply, which applies a bias voltage in which an AC voltage is superimposed on a DC voltage to the carrier 3;

The developer I is a non-magnetic component type developer in which a polarity control material such as a pigment such as carbon or a metal-containing azo dye is dispersed in various thermoplastic resins such as styrene resin or acrylic resin.
It is pulverized to a size of 5 to 20 μm by one classification, and a charge control material is added externally.

Hydrophobically treated silica is used as a charge control material.

Fine particles of O,+μ or less such as alumina and titanium are used, but hydrophobic silica is most preferred.

The charge control material 5 embedded in the four parts 3α is the same as the charge control material added to the developer 1, and hydrophobic silica is most preferable.

The method of embedding is to attach the charge control material to paper, cloth, etc., and rub it onto the surface of the carrier 30 while rubbing it.

The four minute parts 3α formed on the surface of the supporting body 30 are the second
As shown in the figure, the depth is 0.1μ.

The regulating member 4 is made of a metal plate such as stainless steel, and the contact pressure with the carrier 3 is set to about 70 to 200 P/d, and a thin layer of developer is deposited on the carrier 3 to a thickness of about 10 to 50 μm. It is designed to be formed in a thick layer.

The supporting body 3 and the holding body 7 face each other with a gap of 1j200μ.

However, the C1 developer 1 is supplied falling onto the carrier 3 by gravity, is sent to the regulating member 4 by the rotation of the carrier 30, is frictionally charged between the regulating member 4 and the carrier 5, and has a predetermined layer thickness. The developer is formed in a thin layer of developer, and is sent to the holder 7 by rotating the carrier 3 while applying a bias voltage.

The electrostatic latent image 6 on the holder 7 is developed into a visible image by flying towards and adhering to it.

On the other hand, at the sliding contact portion between the regulating member 4 and the supporting member 3, as shown in FIG. Since the charge control material 5 is always supplied, the developer I is constantly charged with a new charge control material 5. When the charge control material 5 is contaminated with the developer composition, it is charged to the same polarity as the developer, cleaned, and removed from the recess 3α.

Since the developer 1 is replaced with a new charge control material 5, the developer 1 is always charged to a constant level by the new charge control material 5.

For this reason, a constant charge can be applied to the developer 1 even after long-term use, and a constant and clear image can always be obtained without capri or thick character images.

Further, a recess 3α is formed on the surface of the supporting body 30.

The charge control material 5 is simply embedded in the four parts 3a, and the standard f! Since there is no need to apply a high voltage to the IJ member 4, the cost is reduced.

Using the non-magnetic component developing apparatus described above, a current printing operation was carried out under the following conditions.

(Conditions) 1. As the developer 1, one containing 2% by weight of @aqueous silica was used.

2. A selenium-based photosensitive material was used as the photosensitive material for the holder 7.

3. 150 m between supporting body 3 and holding body 7 in width mode
It was rotated at rLJ' sec.

4 The electrostatic latent image 6 was charged with +200 to +800V.

5. As the bias voltage, a DC voltage of +a00v superimposed with an AC voltage of +800 Vpp and 500 H2 was used.

6. Fill the charging member 5 with hydrophobic silica in the recess 3α of the carrier 3.
embedded as.

As a result, even after copying approximately 50,000 sheets, an image that was completely unchanged from the initial image was obtained.

As a comparative example, we used a carrier with a smooth surface and developed it under the same conditions as described above using a developer without the addition of a charge control material. The text became thick and no images could be obtained after copying about 5,000 sheets.

Without applying high voltage to the effect control member of the invention, a constant charge can always be applied to the developer over a long period of time, and it is possible to maintain a stable state that does not cause fogging or thick lines of characters over a long period of time. Images can be obtained at low cost.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and Fig. 1C is an explanatory diagram of a non-magnetic component developing device, Fig. 2 is a measurement curve obtained by measuring the size of the concave portion of the carrier with a surface roughness meter, and Fig. 3 FIG. 3 is an explanatory diagram of a charging state of a developer. 1 is a developer, 3 is a carrier, 3α is a recess, 4 is a regulating member,
5 is a charge control member, and 6 is an electrostatic latent image. 7 is a holding body. Applicant Fuji Xerox Co., Ltd. Agent Patent attorney Masaaki Yonehara Patent attorney Tadashi Hamamoto (1 rule fixed distance)

Claims (1)

[Claims] Supplying the developer I to the carrier 3, forming a thin layer of the developer 1 on the carrier 3 by the regulating member 4, and applying electric charge,
The electrostatic latent image 6 is transferred to a holder 7 that holds the electrostatic latent image 6.
A non-magnetic material that develops into a visible image by depositing developer 1 on it.
A non-magnetic component developing device characterized in that minute recesses 3α are formed on the surface of the f11 suspension 3, and a load m control member 5 added to the developer is embedded in the four portions 3α. .