JP3974147B2 - Residual toner recovery device for image forming apparatus - Google Patents

Description

  The present invention relates to a residual toner collecting device of an image forming apparatus, and more particularly to an improvement in the structure of a belt for conveying residual toner.

  In recent image forming apparatuses such as copying machines and facsimile machines, from the viewpoint of resource saving, toner remaining on the surface of the photosensitive member after the transfer of the toner image is scraped off, transported to the developing device, and reused. Recycling is being done. Therefore, in many cases, a toner recycling device is configured by arranging a toner conveying screw in the vicinity of the photosensitive member as a toner discharging device for conveying the scraped toner, and a toner recycling belt for conveying the toner to the developing device.

  In such an image forming apparatus, the toner recycling belt is surrounded by a part of the housing, and the residual toner from the photosensitive member is conveyed and collected to the developer agitating portion of the developing device so as not to be scattered. To recycle the toner. As the toner recycling belt, an endless conveying belt with fins is often used.

  However, when transporting residual toner using a conveyor belt with fins, the residual toner tends to stay in the gap between the fin tip of the conveyor belt and the inner wall of the housing. If the toner is used for a long period of time, the residual toner will rub against the inner wall of the housing with the fins. The agglomerated toner is separated from the inner wall of the housing and sent to the developing device, and even if agitated, the agglomerated state is not fully recovered and is used for development, causing an abnormal image. was there.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a residual toner recovery device of an image forming apparatus that can prevent the generation of aggregated toner by a belt for residual toner recovery.

According to a first aspect of the present invention, there is provided an image forming apparatus according to claim 1, wherein the toner of the image forming apparatus for conveying the residual toner using an endless belt with fins is provided. In the collecting apparatus, the bottom portion is disposed at a portion where the housing for storing the endless belt and conveying the toner with the fin on the bottom surface portion of the endless belt on the tip side of the fin is located on both sides of the tip of the fin. and a slope that connects the side portions together when provided along the longitudinal direction of the endless belt, the slope of the toner is also pushed to the side of the housing by the fin, again of the housing It is formed so as to return to the bottom surface portion .

According to the second aspect of the present invention, in the residual toner collecting apparatus of the image forming apparatus of the first aspect, the slope is driven by toner pushed to the side surface of the housing by the one fin, and the next fin is It is characterized in that it is inclined to fall to the bottom part before it arrives and to be conveyed by the next fin .

According to a third aspect of the present invention, there is provided an image forming apparatus using the residual toner collecting device of the first or second image forming apparatus.

In the residual toner collecting device of the image forming apparatus according to the present invention , since the slope is provided along the longitudinal direction of the endless belt at the portion connecting the bottom surface portion and the side surface portion of the housing that houses the endless belt, It is possible to prevent residual toner from agglomerating and compressing, preventing aggregation of residual toner and adverse effects on the image due to the aggregation toner , and even if residual toner is pushed to both sides of the housing by fins during transportation will come back again into the bottom part on the residence of the toner, there is an effect that the anti-aggregation effectively prevented to thereby Rukoto.

The image forming apparatus according to a third aspect of the present invention has the same effects as those of the above-described claims by using the residual toner collecting device of the image forming apparatus of the first or second aspect .

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings. In the following,

  FIG. 1 is a perspective view showing an overall configuration of a process cartridge unit for an image forming apparatus provided with a residual toner collecting apparatus according to the present invention, and FIG. 2 is a side sectional view of the process cartridge unit of FIG. The process cartridge unit 1 includes a photosensitive drum 3, a developing sleeve 4 of a developing device, a developer stirring member 5, a cleaning device 6, a charging device 7, and a cleaning device 6 in a case 2 around the photosensitive member (hereinafter simply referred to as a case). A recycle conveyance unit 8 is provided for sending the residual toner collected in step 1 to the developer stirring member 5 of the developing device.

  A toner discharge screw 9 is disposed inside the portion where the cleaning device 6 is formed, and the residual toner scraped from the surface of the photosensitive drum 3 by the cleaning blade 10 of the cleaning device 6 rotates in conjunction with the photosensitive drum. The toner is discharged into the case 2 a that houses the recycle conveyance unit 8 through the toner discharge screw 9, and is sent to the developer stirring member 5 by the toner recycle belt 11. The discharge direction of the residual toner by the toner discharge screw 9 is the front side of the drawing sheet, and the toner transport direction by the toner recycling belt 11 is from the left to the right in the drawing.

  The toner recycling belt 11 is an endless belt and includes a large number of fins 12... And one is wound around a pulley 13 provided at the end of the toner discharge screw 9 and the other is wound around a driven pulley 14. The residual toner that has been driven and rotated by a toner discharge screw 9 that rotates in conjunction with the photosensitive drum 3 is sent to the developer stirring member 5.

  FIG. 3 is a perspective view showing the shape of the fin 12 of the toner recycling belt 11 in the embodiment of the residual toner collecting apparatus according to the present invention. The fin 12 in the illustrated example is formed in a dogleg shape so as to be bent along a line perpendicular to the toner recycling belt 11. The fin 12 serves to collect the toner on both sides of the fin 12 in the central portion of the toner recycling belt 11 because the tip portion has a dogleg shape when the residual toner is sent to the developer stirring member 5. The outer side, i.e., the side of the case 2a in the conveying direction, is prevented from going to both sides to prevent the toner from staying or aggregating due to compression.

  FIG. 4 is a perspective view showing the fin shape of the toner recycling belt 11 in another embodiment of the residual toner recovery device according to the present invention. Although the fin 12 of the previous embodiment is entirely shaped like a dogleg, the fin 12a of this embodiment has a dogleg shape only at the tip and the base remains flat. In order to prevent toner retention and aggregation, it is sufficient that at least the tip end is formed in a U-shape, and if the base end is left flat as in the present embodiment, the waist strength of the fin 12a is not reduced. It will end.

  FIG. 5 is a perspective view showing the fin shape of the toner recycling belt 11 in still another embodiment of the residual toner collecting apparatus according to the present invention. The fins 12b of the present embodiment are also generally U-shaped like the fins 12 of the first embodiment, but one side is orthogonal to the longitudinal direction of the toner recycling belt 11 and the other side is the longitudinal direction. It is crossed to make an acute angle with the direction. The other side of the fins 12b is the residual toner supply side to the toner recycling belt 11 by the toner discharge screw 9. That is, since the residual toner is most likely to aggregate at the supply portion from the toner discharge screw 9, the supply-side portion is shaped like a letter to feed the residual toner to the opposite side, effectively preventing stagnation and condensation.

  FIG. 6 is a cross-sectional view showing the shape and structure of both ends of the tip of the case 2a and the fin 12 in still another embodiment of the residual toner collecting apparatus according to the present invention. A connecting portion between the bottom surface portion and the side surface portion of the case 2a is provided with a slope 15 along the longitudinal direction. That is, when the residual toner is pushed to both sides of the case 2 a by the fins 12, it falls on the bottom surface until the next fin 12 comes on the slope 15 and is conveyed by the next fin 12. ing. Since this is repeated in the middle of conveyance, the remaining toner is more effectively prevented from staying and condensing.

1 is a perspective view showing an overall configuration of a process cartridge unit for an image forming apparatus provided with a residual toner collecting device according to the present invention. FIG. 2 is a side sectional view of the process cartridge unit of FIG. 1. FIG. 4 is a perspective view showing the shape of a fin of a toner recycling belt in an embodiment of a residual toner recovery device according to the present invention. FIG. 7 is a perspective view showing the shape of a fin of a toner recycling belt in another embodiment of the residual toner recovery device according to the present invention. FIG. 10 is a perspective view showing a shape of a fin of a toner recycling belt in still another embodiment of the residual toner collecting device according to the present invention. FIG. 10 is a perspective view showing the shape of a fin of a toner recycling belt in still another embodiment of the residual toner collecting device according to the present invention.

Explanation of symbols

1: Process cartridge unit 2: Case around photosensitive member 2a: Case of recycling conveyance unit 3: Photosensitive drum 4: Developing sleeve 5: Developer stirring member 6: Cleaning device 7: Charging device 8: Recycling conveyance unit 9: Toner discharge Screw 10: Cleaning blade 11: Toner recycling belt 12, 12a, 12b: Fin 13: Pulley 14: Driven pulley 15: Slope

Claims (3)

  In a toner collecting device of an image forming apparatus for transporting residual toner using an endless belt with fins, the endless belt is accommodated, and the fin on the bottom surface of the endless belt on the tip side of the fin is stored. The housing for transporting toner is provided with slopes for connecting the bottom surface and the side surfaces along the longitudinal direction of the endless belt at the positions located on both sides of the tip of the fin. A residual toner recovery device of an image forming apparatus, wherein the toner is formed so as to return to the bottom surface of the housing again even when the toner is pushed to the side of the housing by the fin. 2. The residual toner collecting apparatus of an image forming apparatus according to claim 1, wherein the slope is moved to the bottom part until the toner pushed onto the side surface of the housing by one of the fins reaches the next fin. A residual toner recovery device of an image forming apparatus, wherein the residual toner recovery device has an inclination that falls and is conveyed by the next fin. An image forming apparatus using the residual toner collecting device of the image forming apparatus according to claim 1.

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