JPH048432Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention generally relates to a developing device, and in particular, to a developing device in which a one-component developer supplied onto a developer carrier is formed into a developer layer of a predetermined thickness by a regulating member. The present invention relates to a one-component developing device that conveys a developer layer to an electrostatic latent image and develops it into a visible image.

Conventional Technology A dry type developing device for developing an electrostatic latent image formed on an electrostatic latent image holder has conventionally used a two-component developer consisting of toner and a carrier, and the toner is charged by friction with the carrier. Two-component developing devices have been actively developed and put into practical use, in which a charged toner is electrostatically attracted to an electrostatic latent image by applying an electric charge to the electrostatic latent image. Typical two-component development methods include a cascade development method and a magnetic brush development method.
From the viewpoint of copy quality such as solid black reproducibility, magnetic brush development methods have recently become mainstream. As described above, the development method using a two-component developer consisting of toner and carrier is sufficiently practical, but recently, from the viewpoint of improving copy quality such as resolution, and compacting the installation space of the developing device. From the viewpoint of preventing developer deterioration, etc., a single-component developing method and device using a single-component developer consisting only of toner has been proposed. has been desired.

As a non-magnetic one-component development method, U.S. Patent No.
The touch-down development method disclosed in No. 2,895,847 is generally well known, and in this development method, discharge by a corotron is performed as a means for imparting an electric charge to the developer. Although this method is simple, it has many drawbacks, such as the large size of the device and the need to periodically clean the corotron wire.
In order to improve this drawback, we developed non-magnetic one-component development in which a thin layer of developer is formed on the developer carrier and a charge of a desired polarity is applied to the developer using a regulating member that presses against the developer carrier. I proposed the device first.

Problems that the invention aims to solve: This device uses triboelectric charging to give the developer a charge of the desired polarity, but because the friction time is extremely short, conventional developing devices cannot charge enough developer. However, there was a problem in that a large amount of developer could not be obtained in the non-image areas, resulting in so-called foggy copies. In addition, since sufficient charge cannot be applied to the developer, the stress of the regulating member may prevent the developer from being electrostatically held sufficiently on the developer carrier, resulting in a disordered layer, or the developer may fall under the carrier. There were drawbacks such as spillage and contamination of the developing device.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a one-component developing device which solves the above-mentioned drawbacks of the prior art and is capable of producing copied images with almost no fog in non-image areas.

Means for solving the problems In order to solve the problems of the above-mentioned conventional technology,
The present invention includes a developer carrier and a regulating member that comes into contact with the developer carrier to form a thin layer of developer on the developer carrier and to apply an electric charge to the developer by frictional charging. In the developing device for visualizing the electrostatic latent image on the electrostatic latent image holder, the regulating member is formed of a soft elastic body at least at a contact portion with the developer carrier, and the soft elastic body is formed of a base material. A developing device characterized in that it contains a basic dye.

According to a preferred embodiment of the present invention, the hardness of silicone rubber, ethylene propylene rubber, styrene butadiene rubber, epichlorobidrin rubber, chloroprene rubber, butyl rubber, etc. is used as the soft elastic body.
A base material having a temperature of 10 to 70 degrees Celsius is used, and a basic dye is contained in the base material in an amount of 0.05 to 20% by weight. More preferably, the basic dye is contained in an amount of 0.1 to 5% by weight.

Examples of basic dyes include those shown below.

Function Since the regulating member is made of a soft elastic material at the contact portion with the developer carrier, for example, when coarse toner particles enter the contact area between the soft elastic material and the developer carrier, the The elastic body deforms only in the portion of the coarse toner particles. Therefore, it is possible to prevent the stress applied to the toner particles from becoming unnecessarily large, and furthermore, in the contact area, the gap between the regulating member and the developer carrier becomes unnecessarily large, causing other fine toner particles to become unnecessarily large. This eliminates the possibility of particles getting in. Furthermore, if a foreign object gets between the regulating member and the developer carrier, the foreign object can be easily removed because the soft elastic body is always vibrating between the developer carrier and the regulating member. This results in
It becomes possible to form a uniform developer layer on the developer carrier in a stable manner over time.

Furthermore, since the basic dye is contained in the soft elastic body in an amount of 0.05 to 20% by weight, the triboelectric charging characteristics of the toner caused by the regulating member can be significantly improved. As a result, when an electrostatic latent image is developed using the developing device of the present invention, a clean copy image with less fog can be obtained.

Hereinafter, the present invention will be described in more detail based on embodiments with reference to the drawings.

Embodiment 1 Referring to FIG. 1, a schematic configuration diagram of a developing device of the present invention is shown. In FIG. 1, below a hopper 2 in which developer 1 is stored, a developer carrier 5 that carries developer 1 and a developer supply member 4 are provided in pressure contact with each other and are rotatable. ,
The regulating member 3 is attached to the developer carrier 5.
are pressed together with uniform pressure in the axial direction. An electrostatic latent image holder 7 holding an electrostatic latent image 8 facing the developer carrier 5 is rotatably provided, and a bias voltage is applied to the developer carrier 5 by a bias power source 9. There is. 6 is a sealing material.

The image agent 1 is, for example, a non-magnetic one-component developer, in which a polarity control agent 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, and is then pulverized and classified. Depending on 5~
The size of the developer particles is 20 μm, and in some cases, in order to improve fluidity, 0.5
Hydrophobic silica may be added in a range of 2.0% by weight. The developer actually used in this example was 2% by weight of azo dye in a styrene-acrylic binder.
This is a negatively chargeable toner containing 10% by weight of carbon black.

The regulating member 3 is composed of a SUS304CSP3/4H plate spring 3a with a thickness of 0.1 mm, a silicone rubber (hardness of 50 degrees) as a base material, and a soft elastic body 3b containing 5.0% by weight of basic dye Solvent Orange3 adhered to this. did.
The silicone rubber base material is heat-vulcanized silicone rubber KE650-U, KE850-U, KE554-
U, KE555-U, KE752-U (Shin-Etsu Silicone), TSE221, TSE270, TSE260 (Toshiba Silicone), etc. can be used, and these heat-curable silicone rubbers are coated with basic dye using three rolls. Knead it, put it in a mold, heat it, vulcanize it, then cut it to a thickness of 1mm, width of 10mm, and length of 300mm.
Adhere it to the surface of the SUS304CSP3/4H0.1mm leaf spring 3a using adhesive. The silicone rubber base material actually used in the experiment of this example was KE650-U, and basic dye Solvent Orange3 was added to it at a rate of 5.0%.
% by weight to form a soft elastic body 3b.

In this invention, the plate spring 3a is generally made of phosphor bronze, silicon steel, stainless steel, etc. with a thickness of 0.03 to 0.5.
mm can be adopted, and the base material of the soft elastic body 3b is silicone rubber, ethylene propylene rubber, styrene-butadiene rubber, epichlorobidrin rubber, chloroprene rubber, butyl rubber, etc. with a hardness of 10 degrees to 70 degrees. and add basic dye to this
It is possible to use one containing 0.05 to 20% by weight. More preferably, the content of basic dye is 0.1
~5% by weight.

Examples of basic dyes include those shown below.

The developer supply member 4 has a cylindrical shape in which an elastic body 4b such as urethane rubber is bonded to a metal core 4a, and is pressed against the surface of the developer carrier 5 at a predetermined pressure. The developer carrier 5 is constituted by a roll made of conductive phenolic resin, for example, and the regulating member 3 is pressed against the roll at a linear pressure of 50 to 500 g/cm.

The linear pressure actually adopted in this example was 100 g/cm, the developer carrier 5 was rotated at a circumferential speed of 127 mm/sec, and the amount of charge on the developer layer on the developer carrier was measured. is shown in FIG. 3 by a broken line. Further, as a comparative example, the solid line in FIG. 3 shows the case where heat-curable silicone rubber KE650-U, which is a commonly used silicone rubber, was used. As is clear from the graph in Figure 3, by containing the basic dye in the silicone rubber, the average charge amount of the toner increases from -2μc/gr to -15μc/gr, and the toner with opposite polarity (positive charge) increases. There was no existence at all.

Next, the operation of the developing device of the present invention shown in FIG. 1 will be explained below. The developer 1 in the hopper 2 is supplied by gravity onto the elastic body 4b of the developer supply member 4, and is slightly triboelectrically charged due to the rubbing between the supply member 4 and the developer carrier 5, and is given an electric charge. After that, it is sent to the developer carrier 5,
Next, a thin developer layer with a predetermined thickness is formed on the developer carrier 5 by the regulating member 3, and frictional electrification is also generated between the regulating member 3, the developer 1, and the developer carrier 5. A charge is applied to the developer. At this time, the soft elastic body 3b of the regulating member 3 is made of silicone rubber as a base material, and is coated with basic dye Solvent.
Contains 5.0% by weight of Orange3, so
Since the triboelectric charging characteristics with the developer 1 can be significantly improved, the developer layer on the developer carrier 5 is sufficiently charged and is formed into a thin layer with a uniform thickness. be done.

This thin layer of developer is sent to the development area facing the electrostatic latent image carrier 7 by rotating the developer carrier 5 while applying a bias voltage to the developer carrier 5, and the electrostatic latent image 8 The electrostatic latent image 8 flies toward the electrostatic latent image 8 due to the electric field between the developer and the developer carrier 5.
is deposited on top and developed into a visible image.

In this way, the regulating member 3 is composed of the spring plate material 3a and the soft elastic body 3b, and the basic dye is contained in the soft elastic body. The developer can be given a sufficient electric charge. According to the present invention described in detail above, since a stable and uniform thin layer of developer having sufficient charge can be formed on the developer carrier 5, the electrostatic charge on the electrostatic latent image carrier 7 The latent image 8 can be developed faithfully without causing fog. The developer that did not contribute to development remains in a non-uniform state on the developer carrier 5 that has passed through the development area, and a portion of this remaining developer is collected by the supply member 4, and the developer is present. After the developer 1 is supplied by the supply member 4 to the non-conforming areas and the state is corrected to be almost uniform, a thin developer layer of a predetermined thickness sufficiently charged by the regulating member 3 is again applied to carry the developer. It is formed on the body 5.

Example 2 In the silicone base material used in Example 1,
A regulating member 3 was formed by kneading 2.0% by weight of Magenta (Sumitomo Chemical) and using the same conditions as in Example 1 except for the other conditions. This regulating member was adopted in the developing device shown in FIG.
As a result of measuring the amount of charge on the upper developer layer, it was -18μc/
The average charge amount of gr was obtained. Further, as a result of a copy test using this developing device, a clear copy image with no fog in the non-image area was obtained.

Example 3 Using ethylene propylene rubber as the base material, 5.0% by weight of Solvent Orange 3 was kneaded in the same manner as in Example 1 to form a soft elastic body 3b, which was used in Example 1.
A regulating member 3 was formed by adhering to a spring plate material 3a similar to the above. When this regulating member was used in the developing device shown in FIG. 1 and the average charge amount of the developer on the developer carrier 5 was measured, an average charge amount of -25 μc/gr was obtained. As a result of conducting a copy test using this developing device,
A clear copy image with no fog in the non-image area was obtained. As a comparative example, when ethylene propylene rubber into which no basic dye is kneaded is used as the soft elastic body 3b, the average charge amount of the developer is -
It was 3.5μc/gr, and the copied image also had a lot of fog.

Example 4 Silicone rubber and Solvent similar to Example 1
Form a soft elastic body 3b using Orange3,
Figure 4 shows the results of measuring the amount of charge while varying the content of Solvent Orange 3 within the range of 0.01 to 50% by weight. As is clear from Figure 4, Solvent
If the content of Orange3 is less than 0.05% by weight, Solvent
There is not much effect of adding Orange3, 20% by weight
In this case, it is observed that the surface of the rubber does not become uniform and the amount of charge of the developer decreases. As a result,
The content of Solvent Orange 3 is preferably 0.05 to 20% by weight, more preferably 0.1 to 5% by weight.

Embodiment 5 As shown in FIG. 5, a two-component magnetic developer 1' consisting of toner and carrier is used as a developer, and a conventional two-component developing magnet roll 10 is used.
is used as a developer supplying member to feed the weakly charged developer 1' onto the developer carrier 5. Even in this case, the regulating member 3 of the present invention
The developer can be sufficiently charged by using
No fogging was observed in the copied image.

Effects of the invention As described in detail above, in the present invention, the regulating member is formed of a spring plate material and a soft elastic body, and the soft elastic body contains a basic dye, so that the regulating member is charged by friction against the developer. Since the characteristics can be significantly improved, it is possible to provide the developer with a sufficient charge of a desired polarity. Further, when an electrostatic latent image is developed using the developing device of the present invention, a clean copy image with no fogging can be obtained.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of the developing device of the present invention;
The figure is an enlarged cross-sectional view of the regulating member used in the developing device of the present invention, and Figure 3 is a graph showing the charge amount distribution of the developer on the developer carrier. A comparative example is shown in which heat-curable silicone rubber KE650-U, which is a silicone rubber, is used. Figure 4 is a graph showing the relationship between the content of Solvent Orange 3 and the average charge amount of the developer, and Figure 5 is a graph showing the relationship between the content of Solvent Orange3 and the average charge amount of the developer. FIG. 2 is a schematic configuration diagram showing another embodiment of the present invention using the . DESCRIPTION OF SYMBOLS 1... Developer, 2... Hopper, 3... Regulating member, 3a... Spring plate material, 3b... Soft elastic body, 4...
...Developer supply member, 5...Developer carrier, 7...
Electrostatic latent image holder, 9... bias power supply, 10...
magnet troll.

Claims (1)

[Scope of utility model registration request] A developer carrying member and a regulating member that comes into contact with the developer carrying member to form a thin layer of developer on the developer carrying member and apply an electric charge to the developer by frictional charging are provided, and the electrostatic latent In a developing device that visualizes an electrostatic latent image on an image carrier, the regulating member is formed of a soft elastic material at least at a contact portion with the developer carrier, and the soft elastic material has a base material containing a basic material. A developing device characterized by containing a dye.