JPH0648521Y2 - Non-magnetic one-component developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a developing device used in an electrophotographic apparatus or the like, and more specifically, a developer formed on a carrier having a predetermined thickness by a layer forming member. The present invention relates to a non-magnetic one-component developing device which is used as a developer layer and conveys the developer layer to an electrostatic latent image to visualize the electrostatic latent image.

[Prior Art] As a developing device in an electrophotographic copying machine or the like, a developing device employing a cascade developing method, a magnetic brush developing method, a liquid developing method, or the like is widely known. In the developing device adopting these developing methods, it is necessary to replace the developer regularly, so that the working time and labor are spent only for the frequency of maintenance and inspection.

In recent years, a one-component developing method without a carrier has been used as a developing method for reducing the frequency of exchanging the developer. Further, among them, a non-magnetic developer is adopted from the viewpoint of high transparency and applied to color development, and good results have been obtained.

This non-magnetic one-component developing method is described in US Pat. No. 2,895,847.
The "touch-down developing method" is generally well known as disclosed in Japanese Patent Publication No. 2003-242242, and in this developing method, a discharge action by a corotron is used as a means for giving an electric charge to the developer. Although this touch-down developing method is convenient, it has a large apparatus and has drawbacks in terms of work such as requiring periodic cleaning of the corotron wire.

Further, JP-A-47-13088 and JP-A-47-13089 describe inventions relating to impression development and a toner distribution step suitable for impression development. In this impression development, a device consisting of a pressure developing drum that carries toner and conveys it to the photoconductive material, a toner distribution blade, etc. is used, and the pressure developing drum rotates and the toner flowing under the toner distribution blade contacts the blade. Are triboelectrically charged to form a uniform layer, which is brought into contact with the photoconductive material and selectively transferred to the electrostatic latent image. The toner distribution blade is
It is a doctor blade made of polytetrafluoroethylene or the like having a circular tip, and one to three doctor blades are used. On the other hand, the surface of the pressure developing drum is formed of, for example, resin-graphite, and the lower layer thereof is composed of a flexible conductor and an elastic backing material.

However, even in such a structure, in order to obtain a high-quality copy image, it is necessary to form a uniform and thin layer of toner on the surface of the pressure developing drum and impart a charge to the toner.

In order to solve the drawbacks of the touch-down developing method, the inventors of the present invention have made the developer thin by contacting a charge control member on a developer carrier that supplies the developer to the electrostatic latent image carrier. An application has been filed for a non-magnetic one-component developing device capable of forming a layer and, at the same time, imparting a charge having a desired polarity to the developer by the charge control member (Japanese Patent Application No. 59-109737).
issue).

[Problems to be Solved by the Invention] In such a non-magnetic one-component developing device, a thin layer of a developer is formed on a developer carrier by bringing a layer forming member into contact with the developer carrier. However, the charge amount of the developer changes depending on the material of the carrier and the layer forming member that contacts the carrier, and is not always stable. For this reason, in the conventional apparatus, the developer is unevenly conveyed or filming, a copy image having "unevenness" is generated, or the thickness of the developer layer formed on the carrier becomes long after a long operation, that is, There is a problem in that the amount of developer conveyed is reduced, resulting in a copy image with reduced density.

Therefore, an object of the present invention is to form a thin film of the developer, which adheres to the surface of the developing roll and is conveyed to the photoconductor, in a uniform and stable state without causing filming or unevenness, and is a non-magnetic one-component developer. To provide a developing device capable of stably supplying the toner for a long period of time and to improve the copy image transferred from the photoconductor onto the paper.

Another object of the present invention is to provide a stable supply of the developer by making the charge amount in the axial direction of the developing roll surface uniform,
It is an object of the present invention to provide a developing device capable of obtaining a copied image with good image density.

[Means for Solving Problems] In order to solve the conventional problems, the non-magnetic one-component developing device of the present invention comprises a developing carrier for supplying a developer to the electrostatic latent image carrier, and an elastic member for the developing carrier. The electrostatic latent image is visualized by bringing the electrostatic charge control member into contact with the developer, applying a predetermined charge to the developer by the electrostatic charge control member, and adhering the developer on the electrostatic latent image carrier to make the electrostatic latent image visible. The surface is processed and roughened uniformly so as to have a predetermined roughness Rz (JIS standard, 10-point average roughness) over the entire surface in the direction perpendicular to the transport direction. The degree of roughening is 2 μ ≦ from the viewpoint of filming on the carrier and the uniformity of layers over time.
It has been found that Rz ≦ 10μ is suitable.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of an example of a one-component developing device to which the present invention is applied.

In FIG. 1, below the hopper 1 storing the developer 2, a developer carrying member (developing roll) carrying the developer 2 is provided.
4 and the developer supply member 3 are in pressure contact with each other and are rotatably provided.
Are pressed against each other with a uniform pressure in the axial direction of the developer carrying member 4. An electrostatic latent image holding member 6 holding an electrostatic latent image is provided rotatably so as to face the developer holding member 4, and a bias voltage is applied to the developer holding member 4 by a bias power source (not shown). It

The developer 2 is a non-magnetic one-component developer, in which a pigment such as carbon or a polarity control agent such as a metal-containing azo dye is dispersed in various thermoplastic resins such as styrene resin and acrylic resin, and pulverized.
The size is set to 5 to 20 μm by classification, and in order to improve fluidity in some cases, it may be added to the developer particles.
Hydrophobic silica may be added in the range of 0.5 to 2.0% by weight.

The developer supply member 3 has a shape in which an elastic body such as urethane rubber is adhered on a cylinder to a metal cored bar, and rotates while being pressed against the surface of the developer carrier 4 with a predetermined pressure.

The developer carrying member 4 is formed by coating the surface of a solid iron or hollow cylindrical member made of iron with a phenol resin as a semiconductive resin to a thickness of, for example, 1 mm, and a charge regulating member of 50 to 500 g / Pressed with a linear pressure of cm.

As shown in FIG. 2, the charge control member 5 has a structure in which a soft elastic body 9 is joined to an elastic member 8. As the soft elastic body 9, silicone rubber, for example, heat vulcanizing type silicone rubber, such as KE650-U, KE850-U, KE554-U, KE555-U, KE.
752-U (all manufactured by Shin-Etsu Silicone Co., Ltd.), TSE221, TSE27
A material obtained by vulcanizing a base material such as 0 or TSE260 (all manufactured by Toshiba Silicone Co., Ltd.) by containing an acid dye or the like is used.

As the elastic body 8, a leaf spring material having a thickness of 0.03 to 0.5 mm made of a material such as phosphor bronze, silicon steel or stainless steel is used.

In the present invention, as the developer carrying member 4, as shown in FIG. 3, the surface of the lever is roughened in a direction perpendicular to the developer conveying direction. The degree of roughness Rz (JIS standard, ten-point roughness Rz) is in the range of 2μ ≦ Rz ≦ 10μ from the viewpoint of the filming on the carrier and the uniformity of the layer over time as shown in FIG. 4 as a result of the experiment. Turned out to be suitable.

Roughening of the surface of the developer carrying member (developing roll) 4 can be performed as follows, for example, by belt grinding (FIG. 5) or feather cloth grinding (FIG. 6). The difference between the two grindings is only whether the grinding material is the endless belt 11 or the down cloth 12. Therefore, the belt grinding will be described below as an example.

FIG. 5 and FIG. 7 show a state in which the surface of the developing roll 4 is belt-ground, and one of the feed rollers 13 has a rotation shaft inclined as shown in the drawing, and the tip of the developing roll 4 is On the feed roller 13, the developing roll 4 is forcibly fed to the lower part of the grinding belt 11 while rotating,
A groove-shaped pattern 14 (see FIG. 3) is formed on the surface of the developing roller 4 by the grinding belt 11 in a direction perpendicular to the rotation direction. Although the developing roller 4 is spirally fed by the feed roller 13, the pattern shape of the surface of the grinding belt 11 is linear along the axial direction as shown in FIG.

This can be achieved by setting the feed speed of the feed roller 13 and the rotation speed (peripheral speed) of the grinding belt 11 to appropriate values.

Roughness Rz (JIS standard, 10-point average roughness) 2 μm to 2 by using the grain size specifications # 24 to # 1000 of the grinding belt.
It is possible to obtain one having a thickness of 0 μm.

Furthermore, it is preferable to perform the surface treatment with the grinding belt 11 twice. At this time, the surfaces can be made to have a more uniform roughness by making the directions of the first and second thrusts into the grinding belt 11 opposite to each other.

The grain size specification (# 24 to # 1000) of the grinding belt 11 is the same as in the case of the abrasive cloth, and the desired Rz can be obtained by selecting either belt grinding or feather cloth with such specifications. be able to. As described above, the surface of the developing roll 4 surface-treated with Rz = 2 to 10 μm in the axial direction does not leave a fingerprint even if it is touched with a fingertip, and thus no special attention is required in handling.

The belt grinding (Fig. 5) and the feather cloth grinding (Fig. 6) can be easily attached / detached by exchanging the attachment parts of the same machine tool. By any of the grinding methods such as belt grinding and feather cloth grinding, a desired Rz (2 to 10 μm) can be obtained by controlling the rotational speed of the abrasive, the number of times pressure grinding is performed on the developing roll, and the like. The difference between these two grinding methods is that the belt grinding method has a higher upper value of Rz.

The method for polishing the developer carrying member is not limited to the above, and for example, the method for polishing the developer carrying member is sanded from # 320 to # 1200, and is sufficiently sanded by hand in a direction perpendicular to the developer conveying direction. Good.

[Operation] In the apparatus of the present invention shown in FIG. 1, the developer 2 in the hopper 1 is supplied onto the developer supply member 3 by gravity, and the developer 2 is supplied to the developer supply member 3 and the developer carrier 4. After being frictionally charged by rubbing with the developer to give an electric charge, the developer carrying member 4
It is transferred to the charge regulating member 5 while adhering to it, where it is formed into a thin layer having a predetermined thickness by the charge regulating member 5 and has sufficient charge for development having a predetermined polarity.

This thin developer layer is sent to the portion opposite to the electrostatic latent image holding member 6 by rotating the developer holding member 4 while applying a bias voltage, and the electrostatic latent image holding member 6 is rotated by the electrostatic latent image holding member 6. An electric field between the image and the developer carrying member 5 flies toward the electrostatic latent image,
The electrostatic latent image becomes a visible image by adhering on the electrostatic latent image.

The developer that has not contributed to the development remains in a non-uniform state on the developer carrier 4 that has passed through the development area, and a part of the remaining developer is recovered by the supply member 3 and the developer exists. The developer 1 is supplied to the portion not to be supplied by the supply portion 3 to correct it to a substantially uniform state, and then a thin developer layer having a predetermined thickness sufficiently charged by the regulating member 5 is carried on the developer. Formed on the body 4.

[Effect of the Invention] According to the present invention described in detail above, since a stable and uniform thin developer layer having sufficient electric charge can be formed on the developer carrying member 4, the electrostatic latent image holding member can be formed. The electrostatic latent image on No. 6 can be faithfully developed for a long period of time without causing fog and with good gradation.

That is, in the present invention, since the surface of the developer carrying member 4 is roughened in a direction orthogonal to the developer conveying direction so as to have a predetermined roughness, the developer supply member 3 and the developer carrying member 4 are processed. A sufficient amount of electric charge is applied to the developer frictionally charged by the rubbing of the toner by the charge control member so that the developer is surely carried on the developer carrier to which a predetermined bias voltage is applied. A uniform thin layer can be formed.

When a thin layer of the developer thus sufficiently charged faces the developing area of the electrostatic latent image carrier, an appropriate amount of the developer is electrostatically charged according to the electrostatic latent image on the electrostatic latent image carrier. When the developed image is transferred onto the paper, a clear copy image with less fog is attached, because the unnecessary developer does not adhere to the non-image area on the electrostatic latent image holder. Obtainable.

In addition, since the developer uniformly forms a thin layer on the developer carrying member and is sufficiently charged by the charge regulating member,
There is no need to worry that the developer will spill around the developing device and stain the surrounding area.

[Example] In FIG. 1, 2% by weight of azo dye and 10% of carbon black in a styrene-acrylic binder were used as the developer 2.
Negatively chargeable toner containing 1% by weight, a developer supply member 3 made of a stainless steel cored bar with an ethylene propylene dimy material (EPDM) rubber layer bonded to the outer periphery thereof, and a developer carrier 4 made of a phenol resin. It consists of conductive rolls and Rz = 5 in the direction perpendicular to the developer transport direction.
Roughened to 5μ, hardness of 50 as charge control member
Degree silicone rubber as the base material, kneading 1.0% by weight of monoethanolamine with 3 rolls, heating in a mold, vulcanizing and cutting, thickness 1mm, width 10mm, length 3
As a 00 mm soft elastic body, using a device in which this is adhered to the surface of a SUS304CSP3 / 4HO, 1 mm thick leaf spring, the charge control member 5 is pressed against the developer carrier 4 with a linear pressure of 130 g / cm. Then, the developer carrying member 4 was rotated at a peripheral speed of 100 mm / s, and the carrying amount and the charge amount of the developer layer on the developer carrying member were measured. The results are shown in FIG. 8 (conveyance amount) and FIG. 9 (charge amount). In addition,
For comparison, FIGS. 8 and 9 also show the results when the developer carrying member was processed to have the same roughness in the carrying direction.

Further, since the developer carrier has an axial distribution, the amount of charge and the amount of charge at the central portion (B) and at two points (A and C) on both sides were measured. The results are shown in FIG. 10 (conveyance amount) and FIG. 11 (charge amount).

From the results shown in FIGS. 8 to 11, it is clear that when the developer carrying member is roughened at right angles to the carrying direction, it is possible to obtain a sufficient charge amount that is stable over time and a uniform carrying amount.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a non-magnetic single-component developing device of the present invention, FIG. 2 is a cross-sectional view of a charge restricting member used in the device of the present invention, and FIG. 3 is a developing component of the device of the present invention. FIG. 4 shows the relationship between the surface roughness of the developer carrier and the formed developer layer, and FIG. 5 is a perspective view showing belt grinding of the developer carrier, and FIG. Is also a perspective view showing cloth grinding, FIG. 7 is an explanatory view of belt grinding, and FIGS. 8 and 9 show changes with time of the developer transport amount and the charge amount for the example and the comparative example of the present invention, respectively. Is a graph showing
FIG. 10 and FIG. 11 are graphs showing the results of measuring the developer transport amount and the charge amount in the axial direction (three points on the central portion and both sides) of the developer carrying member. Reference numerals in the figure: 1 ... Hopper; 2 ... Developer; 3 ... Developer supply section; 4 ... Developer carrier; 5 ... Charge regulating member; 6 ... Electrostatic latent image holder; 8 ... Leaf spring material; 9 ... Soft elastic body; 11 ... Grinding belt; 12 ... Haber cloth; 13 ...
Feed roller; 14 ... Grinding groove.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tsutomu Kubo 2274 Hongo, Ebina-shi, Kanagawa Fuji Zero Tsux Co., Ltd.Ebina business office (72) Takashi Yamamuro 2274, Hongo, Ebina, Kanagawa Fujizero Tsuxu Ebina business In-house (72) Inventor Kazuhiko Tsukoshi 2274 Hongo, Ebina, Ebina, Kanagawa Prefecture Fuji Zero Tsukus Co., Ltd.Ebina business office (72) Inventor, Takayuki Sunaga 2274, Hongo, Ebina, Kanagawa prefecture Ebina business, Fuji (56) References JP-A-60-73648 (JP, A) JP-A-60-33578 (JP, A) JP-A-60-61776 (JP, A) JP-A-59-210463 (JP, A) JP-A-60-130771 (JP, A) Actual opening 57-65354 (JP, U) Actual opening 58-146249 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A charge control member is brought into contact with a developer carrying member for supplying a developer to an electrostatic latent image holding member, and a predetermined charge is applied to the developer by the charge controlling member to develop on the developer carrying member. In a developing device for forming a thin layer of an agent and visualizing an electrostatic latent image by depositing the developer of the thin layer on an electrostatic latent image holding member, the charge regulating member is an elastic body, A non-magnetic one-component developing device characterized in that the surface of the agent carrier is roughened in a direction perpendicular to the developer conveying direction.