JPH08297411A - Developing device - Google Patents

Abstract

PURPOSE: To provide a developing device capable of forming a stable toner layer having a specified thickness of the toner supplied especially on the toner carrier of a one-component developing device suitable for user maintenance by means of a friction controlling member and realizing a stable toner electrification. CONSTITUTION: The controlling member 24 forming the toner thin layer on the toner carrier 21 by being brought into press-contact with the toner carrier 21 is constituted of a means for pressing the member 24 to a toner carrier 21 side and a toner seal member 26 preventing the toner entering the peripheral part of the pressing means. Since the member 24 is provided with the means for pressing the member 24 to the toner carrier 21 side and the means for preventing the toner entering the pressuring means 25, so that toner flow becomes adequate, the toner is prevented from entering the peripheral part of the means 25, and pressing force is stabilized, the toner thin layer which is always stable can be formed. Thus, the compact developing device suitable for user maintenance can be provided at a low cost with a simple constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-component developing device, and more particularly to a developing device for visualizing an electrostatic latent image by forming a toner layer of a toner supplied on a toner carrier by means of a friction regulating member. Regarding

[0002]

2. Description of the Related Art A conventional device is a developer (hereinafter abbreviated as toner) as disclosed in Japanese Patent Publication No. 63-16736.
In order to regulate the layer thickness of the toner layer on the carrier, the antinode surface presses against the toner carrier to regulate the layer thickness. The tip of the toner powder before regulation is upstream in the moving direction of the toner powder. In the case where the edge of the elastic regulation plate is formed so as to have a reverse pressure contact elastic regulation plate having a free end so that the edge is located, and the antinode surface of the elastic regulation plate is located in the ascending path of the moving path of the toner carrier. Was being considered. Further, a developing device using a forward pressure contact elastic regulation plate described in a known example of the present publication is known.

Normally, the toner carrier is configured to rotate in the opposite direction to the rotation of the toner image carrier. This is because the developing characteristics are improved with respect to the toner image bearing member compared with the case where the toner bearing member is rotated in the same direction, and when the toner bearing member is rotated in the same direction as the toner image bearing member,
This is because problems such as vibration are likely to occur due to an increase in load resistance. Therefore, in general, the layer thickness regulating member of the toner carrier is provided above the center line of the toner carrier.

[0004]

In the above-mentioned prior art, when the toner image bearing member is rotated to the right, for example, the toner bearing member is arranged on the right side or the lower side, and is rotated counterclockwise in the opposite direction to the toner image bearing member. . By doing so, the opposing surfaces of the two move in the forward direction. The paper path is located on the left side or the bottom side. As a result, it is possible to obtain a developing structure with high developing efficiency and less problems such as vibration.

However, the above is the case of monochrome printing.
In color printing and the like, when the toner images developed one by one on the photoconductor are transferred one by one on the intermediate transfer body so as to be superimposed and the color image is formed during a plurality of rotations, the intermediate transfer body is used. If the toner image carrier is rotated to the right, the toner image carrier is rotated to the left and the toner carrier is rotated to the right, which requires the toner carrier to convey the toner from the bottom side of the case. That is,
The regulating surface of the toner layer thickness regulating member must be located in the descending path of the toner image carrier. Therefore, the regulating surface of the toner layer thickness regulating member must be arranged below the center line of the toner image carrier. In this case, the toner remaining after the layer thickness is regulated (excessive amount of supply) falls on the back surface of the layer thickness regulation plate or the like and accumulates and becomes sleeping snow. The toner accumulated here becomes a toner that is never used for a lifetime unless a special toner scooping device is provided. In addition, the toner accumulated in this area in turn overflows with excessive supply of toner, and the toner accumulates and becomes a high pressure and the layer thickness becomes thick. Proper charging cannot be obtained. It causes unevenness and fluctuation of layer thickness.

Further, when the tip of the toner layer thickness regulating plate is a free end, the regulation surface of the toner layer thickness regulating member is minute due to the variation of the friction coefficient between the toner carrier and the regulation surface of the toner layer thickness regulating member. It may fluctuate, which causes fluctuation of the toner layer pressure.

Therefore, it has been difficult to form a uniform and thin toner layer essential for non-magnetic one-component development with the conventional apparatus as described above.

An object of the present invention is to provide a structure which enables the toner supplied on the above-mentioned toner carrier to be stably formed as a thin toner layer of a predetermined thickness over a long period of time, and has a simple structure and a compact structure. Another object is to provide a developing device that realizes a low price.

[0009]

To achieve the above object, a regulating surface of a toner layer thickness regulating member is arranged below a center line of a toner carrier of a developing device. The regulating surface of the toner layer thickness regulating member is composed of a pressurizing means for applying a contact pressure and a toner seal member for preventing the invasion of toner into the periphery of the pressurizing means. The pressurizing means is composed of an elastic force of a leaf spring, a coil spring, or the like.
An elastic body such as a sponge or a rubber plate, or a sheet-shaped thin plate (polyester film sheet, urethane sheet, nylon sheet, etc.) is arranged on the back surface of the regulation surface of the toner layer thickness regulation member as a toner seal member. The toner seal member comes into contact with the case member of the developing device to eliminate a gap in the vicinity and prevent toner from entering. Further, the toner seal member is configured so that an appropriate pressing force acts upon contact with the case member of the developing device, which acts on the regulation surface of the toner layer thickness regulation member. The regulation surface of the toner layer thickness regulating member is a leaf spring or a two-layer structure in which a rubber plate (urethane rubber, silicon rubber, etc.) is attached to the leaf spring, or a rubber plate (urethane rubber, silicon rubber, etc.) is used for a rigid metal plate. It is configured by a laminated two-layer structure.

[0010]

Since the regulating surface of the toner layer thickness regulating member is arranged below the center line of the toner carrier of the developing device, the toner can be conveyed from the case bottom side of the developing device. The toner layer thickness regulating member serves as a toner sealing member that applies a contact pressure to the regulating surface, and that prevents the toner from invading the pressure means (composed of elastic force of a leaf spring or a coil spring) and the periphery of the pressure means. , A sponge, an elastic body such as a rubber plate, or a sheet-like thin plate (polyester film sheet, urethane sheet, nylon sheet, etc.), and the toner seal member contacts the case member of the developing device to eliminate a gap in the vicinity of the toner. In order to prevent the toner from entering, the toner does not enter the periphery of the pressing means, the pressure is stable, and a stable thin toner layer can be formed uniformly.

Further, since a toner seal member is provided on the rear surface of the regulation surface for the toner (excessive supply amount) which remains after the layer thickness is regulated by the toner layer thickness regulating plate, the upper surface of the toner seal member is smoothly slid to collect the toner. Since the toner cannot be clogged, the toner is not clogged and the toner is not piled up to a high pressure.

Further, since the toner seal member is constituted so that an appropriate pressure force acts upon contact with the case member of the developing device and acts on the regulating surface of the toner layer thickness regulating member, the toner regulating surface is Absorbs minute vibrations that occur when the frictional force fluctuates and obtains an appropriate damper effect.

The regulating surface of the toner layer thickness regulating member is a leaf spring or a rubber plate (urethane rubber, silicon rubber, etc.) on the leaf spring.
Two-layer structure in which is bonded, or a rubber plate (urethane rubber, silicon rubber, etc.) is bonded to a rigid metal plate 2
By having a layered structure, uniform contact with the toner carrier can be obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 5, reference numeral 1 denotes a belt-shaped photoconductor as a toner image carrier (hereinafter abbreviated as photoconductor), and around the periphery of the photoconductor 1, four toners T of different colors are filled in the development. The devices 20Y, 20M, 20C and 20K are arranged, the charging device 2 for charging the photoconductor 1, the exposure device 3, the intermediate transfer member 4 placed in pressure contact with the photoconductor 1, the afterimage erasing device 5, the photoconductor cleaning device. 6 is arranged.

A transfer device 7, a paper peeling device 8 and an intermediate transfer member cleaning device 9 are sequentially arranged around the intermediate transfer member 4, and a paper P is placed between the intermediate transfer member 4 and the transfer device 7. A sheet conveying path 10 for passing the transfer section 4b is formed, and a fixing device 11 for fixing the sheet P ′ onto which the toner image T ′ has been transferred is arranged.

The photoconductor 1 is driven in the direction of arrow 12 by a drive mechanism (not shown). Then, first, the photosensitive layer on the surface of the photoconductor 1 is uniformly charged by the charging device 2, and an image and character data by a personal computer, an image scanner, etc. are imaged on the photoconductor 1 in dot units by the exposure device 3, Form an electrostatic latent image. Thereafter, the electrostatic latent image on the photoconductor 1 is developed by the developing device 20 to be visualized as a toner image and sent to the first transfer portion 4a.

Here, the photosensitive member 1 is connected to a voltage of -several hundreds V by a power source (not shown), and the intermediate transfer member 4 is connected to the ground. Therefore, in the image first transfer portion 4a, the toner is transferred from the photoconductor 1 to the intermediate transfer body 4 due to the potential difference.

After passing through the first transfer portion 4a, the photoconductor 1 is irradiated with light by the afterimage erasing device 5 to erase the electrostatic latent image, and the potential is lowered to a certain level or less. After that, the residual toner in the first transfer is cleaned by the photoconductor cleaning device 6, and the next printing operation is ready.

At the time of forming a color image, the developing device 20 is sequentially switched over in the above-described one cycle operation, and the intermediate transfer member 1
By performing a desired cycle of operation in accordance with the timing of the circumference, the toner images can be superposed on the intermediate transfer member 4.

On the other hand, the paper P is supplied to the transfer portion 4b at a timing, and the toner image T'formed on the intermediate transfer body 4 by the above-mentioned operation is transferred to the paper P by the operation of the transfer device 7. Further, it is peeled off from the intermediate transfer body 4 by the paper peeling device 8 and conveyed through the paper conveyance path 10, and the fixing device 11 melts and fixes the toner image on the paper P and discharges it to the paper discharge portion. On the other hand, the residual toner remaining on the intermediate transfer body 4 after the toner image is transferred onto the paper P is cleaned by the intermediate transfer body cleaning device 9 and is ready for the next printing.

1 to 4 are explanatory views of an embodiment of the developing device 20 according to the present invention. The photosensitive belt 1'of the photosensitive member 1 is driven from below to above as shown by an arrow 12. The toner carrier 21 of the developing device 20 is in contact with the photosensitive belt 1'or is held at a gap of about 0.1 to 0.3 and is indicated by an arrow 28.
Is driven like. The material is a conductor such as aluminum or stainless steel or a conductive rubber material. A toner replenishing roller 22 and a toner layer thickness regulating member 24 are arranged around the toner carrier 21. The toner regulating member 24 is pressed against the toner carrier 21 by a pressing means 25 with an appropriate pressing force. The pressurizing means is configured by a leaf spring 25a made of a thin plate such as stainless steel or phosphor bronze or the coil spring 2 shown in FIG.
5b. The regulating surface of the toner layer thickness regulating member 24 may extend the leaf spring material 25a of the pressing means 25 and directly contact the toner carrier 21, or the leaf spring 2 may be used.
Rubber plate 24a (urethane rubber, silicone rubber, etc.) on 5a
Two-layer structure in which is bonded, or a rubber plate (urethane rubber, silicon rubber, etc.) is bonded to a rigid metal plate 2
It has a layered structure. A toner seal member 26 is arranged on the back surface of the toner layer thickness regulating member 24. The toner seal member 26 is composed of an elastic member 26a such as foam sponge and a rubber plate, and a sheet material 26b such as a sheet-like thin plate (polyester film sheet, nylon sheet, urethane sheet, etc.). The toner seal member 26 comes into contact with the case member 27 of the developing device 20 to eliminate a gap in the vicinity and prevent toner from entering. Further, the toner seal member 26 is brought into contact with the case member 27 of the developing device 20 to exert an appropriate pressing force, which causes the toner layer thickness regulating member 24.
It is configured to act on the regulatory side of Further, the regulating surface of the toner layer thickness regulating member 24 is arranged below the center line 29 of the toner carrier 21.

Since the regulating surface of the toner layer thickness regulating member 24 is arranged below the center line of the toner carrier 21 of the developing device 20, the toner is conveyed from the case bottom side of the developing device 20. It will be possible. The regulating surface of the toner layer thickness regulating member 24 is composed of a pressurizing means 25 for applying contact pressure and a toner seal member 26 for preventing toner from entering the periphery of the pressurizing means. The toner seal member 26 is the developing device 20. Since the toner abuts against the case member 27 and eliminates the gap in the vicinity to prevent the toner from entering, the toner does not enter the periphery of the pressurizing unit 25, the pressing force becomes stable, and a stable thin toner layer can be formed uniformly at all times. .

Further, the toner (excessive supply amount) remaining after the layer thickness is regulated by the toner layer thickness regulating member 24 is provided with the toner seal member 26 on the rear surface of the regulation surface, so that the upper surface of the toner seal member slides smoothly. Since the toner cannot be accumulated, the toner is not clogged, and the toner is not piled up to a high pressure.

Since the toner seal member 26 is brought into contact with the case member 27 of the developing device 20, an appropriate pressing force acts, which acts on the regulating surface of the toner layer thickness regulating member 24. , The minute vibration that occurs when the frictional force of the toner regulation surface fluctuates is absorbed, and a proper damper effect is obtained.

The regulating surface of the toner layer thickness regulating member 24 is a leaf spring or a two-layer structure in which a rubber plate (urethane rubber, silicon rubber or the like) is attached to the leaf spring, or a rubber plate (urethane rubber, silicon) on a rigid metal plate. Uniform contact with the toner carrier 21 can be obtained by having a two-layer structure in which rubber and the like) are attached.

[0027]

According to the present invention, the developing device 20 described above is used.
Even when the toner is conveyed from the bottom side of the case, the pressing force of the toner layer thickness regulating member 24 can be stably maintained, so that the toner carrier 2
1 can be formed in a uniform thin layer, stable toner thin layer formation and stable desired toner charging can be achieved, and a 1-component developing device suitable for user maintenance can be realized with a simple configuration in a compact and low-priced developing device. There is an effect that can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a developing device according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a developing device according to a second embodiment of the present invention.

FIG. 3 is a vertical sectional view of a developing device according to a third embodiment of the invention.

FIG. 4 is a vertical sectional view of a developing device according to a fourth embodiment of the present invention.

FIG. 5 is a vertical sectional view of an embodiment of a printing system of the electrophotographic apparatus of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive member, 2 ... Charging device, 3 ... Exposure device, 4 ... Intermediate transfer member, 5 ... Afterimage erasing device, 6 ... Photosensitive member cleaning device, 7 ... Transfer device, 8 ... Paper peeling device, 9 ... Intermediate transfer member Cleaning device, 1
0 ... Paper transport path, 11 ... Fixing device, 20 ... Developing device, 2
DESCRIPTION OF SYMBOLS 1 ... Toner carrier, 22 ... Toner supply roller, 24 ... Toner layer thickness regulating member, 25 ... Pressing means, 26 ... Toner seal member, 27 ... Case member, T ... Toner, P ... Paper.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuomi Onishi 7-1, 1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory, Ltd. (72) Inventor Hachiwa ▼ Toru Omika, Hitachi-shi, Ibaraki 7-1, Machi, Hitachi, Ltd., Hitachi Research Laboratory, Ltd. (72) Inventor, Hiroyuki Tadokoro, 1-1-1, Higashitaga-cho, Hitachi, Hitachi, Ibaraki (72) Invention, Electrical Equipment Division, Hitachi, Ltd. Kazuhiro Wakamatsu 1-1-1 Higashitaga-cho, Hitachi-shi, Ibaraki, Ltd. Inside the Taga Headquarters, Electric Equipment Division, Hitachi, Ltd.

Claims (7)

[Claims] 1. A toner thin layer is formed on a toner carrier by forming a thin layer of the triboelectrically charged toner on the toner carrier by means of a fine colored powder toner and a friction regulating member that is pressed against the toner carrier. In the developing device, which conveys the toner carrier to an opposite position on the image carrier on which the electrostatic latent image is formed and visualizes the electrostatic latent image, the friction regulation member is a regulation surface of the toner carrier. And a toner seal member for preventing the invasion of the toner into the periphery of the pressing means. 2. A thin layer of the triboelectrically charged toner is formed on the toner carrier by using a toner of a minute colored powder and a friction regulating member which is pressed against the toner carrier. In a developing device for visualizing the electrostatic latent image by transporting the formed toner carrier to an opposing position on the image carrier on which the electrostatic latent image is formed, the friction regulating member may be the toner carrier. A developing device having a toner seal member for preventing the toner from entering the surface opposite to the regulation surface in contact with the developing device. 3. The developing device according to claim 1, wherein the friction regulating member is arranged below a central axis of the toner carrier. 4. The developing device according to claim 1, wherein the friction regulating member is a leaf spring member for contacting and pressing the friction regulating member with the toner carrier. 5. The developing device according to claim 1, wherein the toner seal member is an elastic member or a sheet-shaped member. 6. The toner sealing member of the friction regulating member according to claim 1, wherein the toner sealing member is an elastic member, and the regulating surface contact pressure of the friction regulating member on the toner carrier is
A developing device which is added by utilizing the elastic force of the toner seal member. 7. The developing device according to claim 1, wherein a rubber-like member having elasticity is disposed on a regulation surface of the friction regulation member which comes into contact with the toner carrier.