JPH04355481A - Toner attracting device - Google Patents

Abstract

PURPOSE:To provide a toner attracting device having a sufficient attracting effect with a simple structure. CONSTITUTION:A lower developing housing 1B has a two-layer structure of vertically dividing the space with a developing roller 4 into two parts. The magnetic brushes M of the developing roller 4 are slid onto its upper wall 1BU side, and a communicating hole 15 allowing the upper space S1 divided between the magnetic brushes M to communicate with the lower space S2 is formed on the upper wall 1BU, and an attracting hole 16 for attracting and recovering a toner is formed on the lower wall 1BL.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner suction device used in a developing section of an image forming apparatus such as an electronic copying machine.

0002

2. Description of the Related Art Conventionally, for example, a developing device of a high-speed copying machine is constructed as shown in FIG.
The developer (a two-component developer made by mixing carrier (iron powder, etc.) and toner at a certain ratio) housed in the developer housing 1 consisting of A and the lower developer housing 1B is moved by a paddle roller (
(not shown), and the developer frictionally charged by this stirring is transported by the transport roller 2A to the side of developing rollers 4 and 5 arranged in two stages facing the photoreceptor drum 3, and the transported developer By sliding the latent image on the photoreceptor drum 3 by the developing rollers 4 and 5, toner is attached to the latent image formed on the photoreceptor drum 3, and the latent image is developed (multi-stage development). The excess developer on the developing roller 5 side is returned to the conveying roller 2A side through a passage above the developing housing 1 by a recovering conveying roller 2B.

The developing rollers 4 and 5 have a structure in which cylindrical developing sleeves 8 and 9 made of a non-magnetic material are rotatably provided on the outside of magnet structures 6 and 7 to which a plurality of permanent magnets are fixed. (The outer conveyance sleeves of the conveyance rollers 2A and 2B are rotatable relative to the internal magnet structures.) The magnetic force from the magnet structures 6 and 7 causes the development to occur on the surfaces of the development sleeves 8 and 9. A magnetic brush is formed by supporting the agent, and this magnetic brush is caused to rub against the photosensitive drum 3 by rotation of the developing sleeves 8 and 9. still,
The magnet structures 6 and 7 are press-fitted or adhesively fixed to magnet roller shafts 10 and 11 fixed to the developer housing 1 side, and the layer thickness of the developer supported on the surface of the developer sleeve 8 is controlled by a layer thickness regulating member 12. It is regulated to be uniform in the axial direction. Furthermore, the developer conveyed to the developing roller 4 side is regulated by the regulating end 13A of the partition plate 13 to prevent the developing roller 4 from being immersed in the developer.

0004

In the developing device having such a conventional structure, in order to prevent toner from blowing out and scattering from between the developing roller 4 and the lower developing housing 1B that covers the lower part of the developing roller 4, Toner accumulated between the developing roller 4 and the lower developing housing 1B is sucked and collected by a toner suction device, and as shown in FIG. 5, a suction port 14 for sucking and collecting the toner is provided in the lower developing housing 1B. was forming. However, with this configuration, toner suction varies depending on the position of the suction port 14 formed in the lower developing housing 1B, and a sufficient suction effect cannot be obtained. That is, when the magnetic brush M formed on the surface of the developing sleeve 8 is in contact with the inner surface of the lower developing housing 1B, toner will accumulate in the area where the magnetic brush M is not in contact. If the magnetic brush M is located at a distance from the magnetic brush M, the magnetic brush M prevents toner suction at the A and B portions, making it impossible to obtain a sufficient suction effect. The present invention has been made in view of these points, and an object of the present invention is to provide a toner suction device that has a simple configuration and can obtain a sufficient suction effect.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a toner suction device having a suction means for suctioning and collecting toner accumulated between a developing roller and a lower developing housing that covers the lower part of the developing roller. , the space between the lower developing housing and the developing roller is divided into upper and lower parts.
The magnetic brush of the developing roller is in sliding contact with the upper wall side, and a communication hole is formed in the upper wall to communicate the divided upper space and lower space between the magnetic brushes. However, a suction port for sucking and collecting toner is formed in the lower wall thereof, and the suction means is also used as a suction means in another part.

[0006]

[Operation] According to this structure, the toner accumulated between the developing roller and the lower developing housing is reliably sucked and collected without being hindered by the magnetic brush on the developing roller side.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The toner suction device of the present invention will be described below with reference to the drawings. It should be noted that the same parts as those in the prior art will be given the same reference numerals and the explanation thereof will be omitted. In this embodiment, as shown in FIG. 1, the lower developing housing 1B is connected to the developing roller 4.
The magnetic brush M of the developing roller 4 is brought into sliding contact with the upper wall 1BU side of the upper wall 1BU, and the upper space S1 is divided between the magnetic brushes M. Communication hole 15 (
In this case, a slit extending in the axial direction of the magnet roller is formed in the upper wall 1BU, and a suction port 16 for collecting toner by suction is formed in the lower wall 1BL. Then, suction is carried out by a suction fan 18 through a suction pipe 17 connected to a suction port 16, and a filter 19 for collection is used.
The toner is collected at the here,
Arrows in the figure indicate airflow generated by the rotation of the suction fan 18, and the toner is sent to the filter 19 by this airflow.

Therefore, in the toner suction device having such a structure, the magnetic brush M on the developing roller 4 side comes into contact with the upper wall 1BU side of the lower developing housing 1B having a two-layer structure, so that the magnetic brush M on the lower developing housing 1B side Excess toner from the developing area (photosensitive drum side) that accumulates can be scraped up into the developing housing 1, and the internal pressure and air flow generated by the flow of the developer conveyed from the conveying roller 2 side are stopped. It is possible to prevent the toner from blowing out toward the groove side of the lower developing housing 1B due to this. The toner existing between the magnetic brushes M can be reliably sucked from the suction port 16 through the communication hole 15 through the lower space S2 without being hindered by the magnetic brush M, and excess toner from the developing area can be removed. Accumulation between the developing roller 4 and the lower developing housing 1B can be prevented. Therefore, it is possible to reduce stains caused by toner falling between the developing roller 4 and the lower developing housing 1B. Further, as shown in FIG. 2, if a second suction port 20 and its suction pipe 21 are provided below the end of the lower developing housing 1B so that the toner falling from the photoreceptor drum 3 is also suctioned and collected, the toner can be removed. It is possible to further reduce dirt. Furthermore, as shown in FIG. 3, the upper wall 1BU of the lower developer housing 1B may be made into a separate body and combined into the lower wall 1BL that is integrated with the lower developer housing 1B. In this embodiment, a multi-stage development system in which a plurality of developing rollers are arranged for the photosensitive drum has been described, but the present invention is not limited to this, and a single developing roller may be arranged.

[0009]

Effects of the Invention As described above, according to the toner suction device of the present invention, the lower developing housing that covers the lower part of the developing roller can
The layered structure ensures that toner accumulated between the developing roller and the lower developing housing can be suctioned and collected, preventing toner from blowing out from between the developing roller and the lower developing housing, and preventing toner contamination inside the device. can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a toner suction device of the present invention.

FIG. 2 is a sectional view of main parts showing another embodiment.

FIG. 3 is an exploded perspective view showing another embodiment of the lower developing housing.

FIG. 4 is a schematic cross-sectional view showing the configuration of a conventional developing device.

FIG. 5 is a sectional view of the main parts of the toner suction device.

[Explanation of symbols]

4, 5 Developing roller 1B Lower developing housing 1BU Upper wall 1BL lower wall S1 Upper space S2 lower space 15 Communication hole 16 Suction port 18 Suction fan

Claims (2)

[Claims] 1. A toner suction device comprising a suction means for sucking and collecting toner accumulated between a developing roller and a lower developing housing that covers a lower part of the developing roller, wherein the lower developing housing is connected to a space between the developing roller and the lower developing roller. The magnetic brush of the developing roller is in sliding contact with the upper wall side of the upper wall and the upper space is divided into upper and lower parts. 1. A toner suction device, characterized in that the toner suction device is formed in a wall, and has a suction port formed in the lower wall thereof for sucking and collecting toner. 2. The toner suction device according to claim 1, wherein the suction means is shared with a suction means provided in another part.