JPS5930563A - Developing device - Google Patents

Abstract

PURPOSE:To enable the formation of a toner layer having a uniform distribution of electrostatic charge on a toner holding body, by coating the toner conveyance surface of the toner holding body with a resin and providing a toner regulating blade in proximity to the coated toner conveyance surface. CONSTITUTION:The toner 4 supplied from a toner supply part 3 is held on the toner conveyance surface of a toner holding body 5. Said surface is coated with a resin 6 vulnerable to electrostatic charging by friction and the surface of the resin 6 is sandblasted to permit easy holding of the toner. A toner regulating blade 7 is provided in proximity to the conveyance surface, whereby a toner layer having a uniform distribution of electrostatic charge is formed on the toner holding body. The toner layer having the electrostatic charge of the extent at which no adverse influences are given to the image quality is formed at the uniform distribution of the electrostatic charge on the body 5 in the above- mentioned way, whereby the always stable and sharp image quality virtually free from ground fogs is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates, for example, to a developing device for developing an electrostatic latent image formed on a photosensitive drum of an electronic copying machine.

[1. Technical background of Ming] Recently, as a developing device for this glaze, a grid consisting of a plurality of parallel wires has been installed between the photosensitive drum as an image bearing member and the developing roller as a toner holding member. The grid and developing roller are provided with DC and AC IN. Alternatively, by applying one of these bias voltages, the one-component toner conveyed by the developing roller is caused to fly, and the 75\
A kind of ・? between the developing roller and the grid? C. A device was developed that developed the electrostatic latent image on the C1 photoreceptor drum in a cloud state.

[Problems with background technology]

However, this type of developing device has the following problems. That is, in order to obtain reliable image quality, it is necessary to form nine layers of toner having a uniform charge amount distribution on the developing roller as a toner holding member.
In conventional devices, sufficient frictional electrification of the toner cannot be obtained because only the toner is charged by friction with a regulating blade provided close to the developing roller. For this reason, the amount of charge on the i-toner may be insufficient or uneven, which may adversely affect the flight of the toner, resulting in an adverse effect on the quality of the copied image, resulting in blurring due to soil force, etc. [Objective of the Invention] The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a uniform charge amount distribution on the toner holder and to an extent that does not adversely affect the image quality. To provide a developing device capable of forming a single layer of toner having a charge amount of 1,000 yen, thereby always providing stable and clear image quality without blurring or blurring.

[Summary of the invention]

The present invention has the following advantages: by coating the toner conveying surface of the toner holder with a resin and providing a toner regulating blade in close proximity to or almost in contact with the toner conveying surface coated with the resin, A single layer of toner having a charge distribution is formed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, J is an image carrier in an electronic copying machine, such as a photosensitive drum, on the surface of which an electrostatic latent image corresponding to the image of the original is formed by an exposure means (not shown), and is indicated by the arrow a in the figure. Rotate in the direction. Note that this photosensitive drum 1 is electrically grounded to VC. Developing devices # and 2 are disposed in close proximity to a portion facing the photosensitive drum 1. Regarding this developing device 2, 3 is a toner supply section 5 which supplies mono-component toner (either magnetic toner or non-magnetic toner 7) 4;
denotes a toner holder, such as a conductive developing roller, which conveys the toner 4 supplied from the toner supply section 3. Its surface is coated with a resin 6 that is easily triboelectrically charged, and it moves in the direction of the arrow in the figure. Rotate to . The surface of the resin 60 is sandozorasted to facilitate retention of the toner 4. As the resin 6, a methacrylate resin is used when the toner 4 is negatively chargeable, and a fluorine resin is used when the toner 4 is positively chargeable. Apply to the surface.

In addition, as the methacrylate resin, Mitsubishi Rayon's Acrycon, Acryniwato M1 Acryvet SM1
Sumipex MO, Sumipex LG, and Sumipex LO manufactured by Sumitomo Chemical.

Asahi Kasei H's Perno Kuuda, Pervet) 5ON, Perpera) 6ON, Sani Rayon's Pabic (a copolymer of methyl metal acrylate and α-methylstyrene), etc. are used. 'In addition, as fluororesins, Polyflon F-101, Polyflon F-103, Polyflon D-1 manufactured by Daikin Industries, and Teflon 6J manufactured by Mikata Fluorochemicals are used.
.

Deflon 6 CJ, Teflon: 305 tiger is used.

In addition, 7 is a toner regulating blade, the tip of which is close to the surface of the virtual roller 5 coated with resin 6 (depending on the material).
The rollers 5 and 5 may be in substantially contact with each other, and the toner conveyed by the developing roller 5 is uniformly leveled. A grid 8 is disposed between the photosensitive drum 1 and the developing roller 5. This grid 8 is made up of a plurality of conductive wires 9 arranged in parallel with each other, as shown in FIG. 20, respectively. Each of the wires 9 is arranged in an arc so as to be concentric with the photosensitive drum 1 so that the distance from the surface of the photosensitive drum 1 is the same as shown in FIG. ing. Here, each of the above wires 9
... has an insulating thin film formed on its surface, has a diameter of 120 μm, and is arranged at intervals of one wing. The insulating thin film on the surface is necessary to prevent discharge from occurring between the developing roller 25 and the photosensitive drum 1.

On the other hand, 1 and 12 are bias power supplies to the developing roller 5, 1 and 1 are DC power supplies, and 12 is an AC power supply. Further, 13 and 14 are bias power supplies to the grid 8, 13 is a DC power supply, and 14 is an AC power supply. Note that the DC power supply I J , 1.9 has a polarity (positive or negative) of the output voltage depending on the polarity of the toner used, a switching switch,
It can be switched by is, it;

In such a configuration, as a first experiment, for example, a non-magnetic negatively charged toner is used as the toner 4,
Use Acrybet SM as the resin 6, set the output voltage of DC power supply 1 to -200yYYF3, set the output voltage of AC power supply 12 to 2000° (frequency is 1 k), and set the output voltage of DC power supply 13 to +20 Orrr. 14 output voltage to 1000 volts (frequency is 1kHz
), the output voltages of the AC power supplies 12 and 14 were set to the same phase, and the results showed that compared to when the resin 6 was not coated under the same conditions, stable and clear image quality without any ground blur was obtained. It was done. That is, by coating the surface of the developing roller 5 with the resin 6, not only the toner 4 is tribo-electrified by the regulation blade 7, but also the amount of charge is increased due to the frictional electrification with the resin 6, and the amount of uncharged toner is reduced. . Therefore, with a uniform layer thickness and uniform charge amount distribution on the developing roller 5,
Moreover, it is possible to form a single layer of toner having a sufficient amount of charge to prevent blurring in the copied image. As a result, there is no blurring in the copied image, and the image quality of the copied image is significantly improved.

Next, as a second experiment, for example, a non-magnetic positively charged toner was used as the toner 4, Polyflon F'-101 was used as the resin 6, and the output voltage of the DC power supply 11 was increased by +2.
00? The output voltage of the DC power source 13 was 1,200 volts, and the other conditions were the same as in the first experiment. As in the first experiment, there was no ground braking. Stable and clear image quality was always obtained.

FIG. 3 shows another embodiment of the invention. In this embodiment, the toner regulating blade 7 is made of, for example, conductive rubber, and a predetermined potential is applied thereto from a DC power source 17. Note that 18 is a changeover switch for switching the polarity of the output voltage of the DC power supply 17.

In such a configuration, an experiment similar to that of the above embodiment was conducted, and as a result, an even greater effect was obtained.

That is, in addition to the frictional charging caused by the regulating blade 7 and the frictional charging with the resin 6 on the developing roller 4, charge injection from the regulating blade 7 to the toner 4 occurs, increasing the charging probability of the toner 4, and causing the uncharged toner to become decreases significantly. Therefore, the image quality of the copied image is further improved by further eliminating the ground force blur. In addition, in the first experimental example, the output voltage of the DC power supply 17 was -30°? the root and the second
In the experimental example, the above output voltage was set to +300? Ruto.

In the above embodiment, a case has been described in which the present invention is implemented in a developing device for an electronic copying machine, but the present invention is not limited thereto, and can be similarly implemented in a developing device such as an electronic printer or a facsimile machine.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to form a single layer of toner on the toner holder with a uniform charge distribution and a charge amount that does not adversely affect image quality. It is possible to provide a developing device that can obtain clear image quality.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing details of a grid in the same embodiment, and FIG. 3 is a block diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Photosensitive drum (image carrier), 2... Developing device, 3... Toner supply section, 4... Toner, 5... Developing roller (toner holding body), 6... Resin, 7... Toner regulation blade, 11.17... DC power supply, No. 2.
··AC source. Figure 1 Figure 2

Claims (2)

[Claims] (1) The toner supply unit includes a toner supply unit, and a toner holding body that is disposed close to the toner supply unit and the image carrier on which the electrostatic latent image is formed and conveys the toner supplied from the toner supply unit. , a developing device that develops the electrostatic latent image by causing the toner conveyed by the toner holder to fly by applying a bias voltage to the toner holder; 1. A developing device comprising: a toner regulating blade provided in close proximity to or substantially in contact with a toner conveying surface coated with the resin; (2) The developing device according to claim 1, wherein the toner regulating blade is formed of a conductive member and a predetermined potential is applied thereto.