JPH10240095A - Cleaning device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cleaning function, and to prevent the soiling of a device inside or an image on recording paper by providing a cover for intercepting toner scattering on a sheet state member side, from a diameter changing section of a transporting screw to the side of a large diameter section in the vicinity on the upstream side in the toner transporting direction. SOLUTION: This cleaning device respectively arranges by disposing the screw large diameter section 20a in a casing, and the screw small diameter section 20b so as to project outside the casing through a penetrating hole 16d provided on a side plate 16c. Moreover, a cover 16e in a circular-arc shape is provided so as to project inward in a specific range, on the side plate 16c inside surface and in the periphery of the penetrating hole 16d. Namely, the circular-arc shape cover 16e is disposed so as to cover the side of the screw large diameter section 20a in the toner transporting direction on the upstream side vicinity from the diameter changing section 20c of the transporting screw 20. The side position on which the circular-arc shape cover 116e is, the position for intercepting a scattering path of the toner scattering from the vicinity of the diameter changing section 20c to a scraper by the rotation of the transporting screw 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic copying machine,
The present invention relates to a cleaning device for an image forming apparatus, such as an electrostatic recording apparatus, that removes, collects, and discharges toner remaining on an image bearing member.

[0002]

2. Description of the Related Art Generally, in various image forming apparatuses such as an electrophotographic copying machine, an original is placed in a fixed or moving state on an original glass table and an illumination lamp or the like constituting an image reading means is attached to the original. The original image is read by moving the image relative to the image, an electrostatic latent image corresponding to the image is formed on the image carrier, developed, and the obtained toner image is transferred onto recording paper to form an image. I'm trying to do it.

[0003] Such an image forming apparatus is provided with a cleaning device that removes, collects, and discharges the untransferred toner remaining on the surface of the image carrier after transferring the toner image onto the recording paper. In such a cleaning device, the untransferred toner on the surface of the image carrier is scraped into the cleaning device by a cleaner blade, and the scraped toner is collected by a rotating cleaner roller, and the toner collected by the cleaner roller is removed. Is scraped off by a sheet scraper and guided to a transport screw. The transport screw is arranged so that the upstream side is disposed in the apparatus and the downstream side protrudes outside the apparatus. When the transport screw is driven to rotate, the toner collected by the transport screw is removed from the apparatus. The toner is further transported to the downstream side by a transport screw extending outside the apparatus, and is discharged to the outside.

Another cleaning device is known in which toner scraped off by a cleaner blade is guided to a conveying screw via a sheet-shaped toner seal member without providing a cleaner roller.

In these cleaning devices, various parts such as a motor, a solenoid, and a gear are arranged near the toner discharge port of the cleaning device in order to reduce the size of the device body. To
The diameter of the transport screw extending outside the cleaning device is reduced. That is, the transport screw is configured such that the screw diameter outside the cleaning device is smaller than the screw diameter inside the cleaning device.

[0006]

In such a cleaning apparatus having a conveying screw having different screw diameters, a large amount of toner stays in a portion where the screw diameter changes from large to small, and this toner is rotated by the rotation of the conveying screw. As a result, the toner is scattered and accumulates on the scraper or the toner seal member near the conveying screw described above, which hinders the collection of the toner on the conveying screw, thereby deteriorating the cleaning function.

Further, since the sheet-shaped scraper and the toner seal member described above have low strength at the ends thereof, in the former case, scattered toner accumulates between the scraper and the cleaner roller, and the accumulated scattered toner accumulates. If the amount is too large, the scraper will bend up, and in the latter case, the scattered toner will be deposited between the toner seal member and the image carrier, and if the amount of the scattered toner is too large, the toner seal member will be turned up. In both cases, there is a problem that the toner leaks out of the cleaning device from the portion where the curl is caused to fall and falls, thereby contaminating the image inside the apparatus or the recording paper.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cleaning apparatus for an image forming apparatus which can solve such problems, improve the cleaning function, and prevent the inside of the apparatus and recording paper from being stained.

[0009]

According to a first aspect of the present invention, there is provided a cleaning apparatus for an image forming apparatus having a large diameter portion and a small diameter portion having different screw diameters. A conveying screw disposed in the cleaning device, the small-diameter portion including a conveying screw disposed outside the device, and conveying the toner removed from the surface of the image carrier via a sheet-shaped member disposed in the device. The cleaning device of the image forming apparatus collects and collects the collected toner in the large diameter portion of the screw, and conveys and discharges the collected toner through the large diameter portion and the small diameter portion by driving the conveyance screw. A cover is provided on the side of the large-diameter portion near the upstream side in the transport direction to block toner scattering to the sheet-like member side.

According to a second aspect of the present invention, there is provided a cleaning device for an image forming apparatus.
The sheet-shaped member includes a cleaner roller for collecting the toner removed from the surface of the image carrier, and the sheet-like member is a scraper whose upper end portion rubs against the cleaner roller, scrapes off the toner collected by the cleaner roller, and guides the toner to the transport screw. It is characterized by:

According to a third aspect of the present invention, a cleaning device for an image forming apparatus is provided.
The sheet-like member is characterized in that the upper end portion is a toner seal member that guides the toner removed from the surface of the image carrier to the conveyance screw while approaching the surface of the image carrier.

According to the cleaning device of the image forming apparatus according to the first to third aspects, even if the toner staying at the portion where the diameter of the transport screw changes is scattered toward the sheet-like member by the rotation of the transport screw. By a cover provided on the side of the large diameter portion near the upstream side in the toner conveyance direction from the diameter change portion of the conveyance screw,
The scattering is blocked, and the accumulation of the scattered toner on the sheet-like member is prevented.

According to another aspect of the present invention, the above object is achieved.
The cleaning device for an image forming apparatus according to any one of claims 1 to 3,
In addition to any one of the above, at least one of the large-diameter portion near the upstream side in the toner conveyance direction from the diameter change portion of the conveyance screw and the cover that blocks the toner scattering is tapered from the upstream side in the toner conveyance direction to the downstream side. It is characterized by having a tapered shape.

According to the cleaning device of the image forming apparatus of the fourth aspect, at least one of the large diameter portion near the upstream side in the toner conveying direction from the portion where the diameter of the conveying screw changes and the cover for blocking toner scattering are used. Since it is configured in a tapered shape that tapers from the direction upstream to the downstream, the toner stagnation in the diameter change portion of the transport screw is reduced, and toner transport in the diameter change portion is
It will be performed better.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Prior to this, an outline of an image forming apparatus will be described using an electrophotographic copying machine as an example.

In the electrophotographic copying machine shown in FIG. 1, an original glass table 2 as an original table is provided on the upper surface of the apparatus main body 1, and a document glass table 2 is provided immediately below the original glass table 2. And a scanner (scanning optical device) 3 constituting an image reading means. The scanner 3 has an irradiation lamp 3a for irradiating scanning light to a document (not shown) on the document glass table 2, and
A reflection mirror 3b and a projection lens 3 for guiding reflected light from a document onto an image carrier (hereinafter, referred to as a photosensitive drum) 4 described below.
c.

An original supply device 5 is provided on the original glass table 2 so as to cover the original glass table 2 so as to be openable and closable. The original supply device 5 includes the illumination lamp 3
a is stopped at a predetermined position, and a document feeder (DF) 5a for scanning (sheet through) for reading while transporting the document onto the document glass table 2; An automatic document feeder (AF) that stops at a position and performs reading while moving the illumination lamp 3a
5b.

A photosensitive drum 4 is provided below the scanner 3 so as to rotate clockwise in the drawing. Around the photosensitive drum 4, a charger 6 for uniformly charging the photosensitive drum 4, the scanner 3
A developing device 7 that supplies toner to an electrostatic latent image formed on the photosensitive drum 4 by exposing the scanning light from the photosensitive drum 4 to visualize the electrostatic latent image; A transfer charger 8 for transferring the upper toner image to the recording paper side, a separation charger 9 for separating the transferred recording paper, and a toner remaining on the photosensitive drum 4 after transfer is removed, collected, and discharged. The cleaning devices 10 and the like are sequentially arranged along the rotation driving direction of the photosensitive drum 4.
The detailed configuration and operation of the cleaning device 10 will be described later.

Further, the toner image on the recording paper is thermally fixed to the exit side end of the belt-shaped paper conveyance path 11 extending from the transfer charger 8 and the separation charger 9 to the exit of the apparatus main body. A fixing device 12 is disposed, and a discharge tray 13 is mounted at an outlet of the fixing device 12.

A paper feed cassette 14 for storing cut recording paper for each size is provided immediately below the belt-shaped paper transport path 11 so as to form a four-stage paper feed unit. A roll paper 15 is arranged so as to be able to be pulled out in the vicinity of the exit side of each of the paper feed cassettes 14.

As shown in FIG. 2, the above-described cleaning device 10 forms a casing of the cleaning device and has a casing 16 having an opening formed on the side facing the surface of the photosensitive drum 4 and a casing 16 having an opening formed on the side thereof. The cleaner 1 is provided with a cleaner blade 17 positioned therein.
6, a cleaner roller 18, a scraper 19, and a transport screw 20 are provided.

The casing 16 includes a cleaner base 16a forming the bottom surface, an upper lid 16b forming the upper surface, and a side plate 16c forming the side surface (see FIGS. 3 and 4).

The cleaner blade 17 has a base end with an upper lid 16.
b is fixed to a portion above the opening, and is provided so that the leading end thereof rubs against the photosensitive drum 4.

The cleaner roller 18 is disposed below the cleaner blade 17 and is provided so as to be driven to rotate counterclockwise in the figure.

The scraper 19 is made of a sheet-like member (film-like member), and has a base end fixed to the lower surface of the casing 16 and a tip end rubbed against the cleaner roller 18. The scraper 19 is also inclined so that the toner on the scraper is directed to the conveying screw 20.

As shown in FIGS. 3 and 4, the transport screw 20 is composed of a large screw portion 20a having a different screw diameter and a small screw portion 20b, and is rotated clockwise in FIG. It is provided to be driven. The screw large-diameter portion 20a is arranged inside the casing 16, and the screw small-diameter portion 20b is arranged so as to project out of the casing 16 through a through hole 16d provided in the side plate 16c. A pipe 21 is fixed to the outer surface of the side plate 16c coaxially with the through hole 16d, and the screw small diameter portion 20b is inserted and arranged in the pipe 21.

The screw small diameter portion 20b and the pipe 21
And the gap between the screw large-diameter portion 20a and the cleaner base 16a are set to predetermined gaps that allow good toner conveyance.

The reason why the diameter of the screw outside the casing 16 is reduced is as described in the prior art. To reduce the size of the apparatus body, a motor or solenoid disposed near the toner outlet of the casing 16 is used. This is to avoid interference with various parts such as gears and gears.

An arc-shaped cover 16e, which is a feature of the present invention, is provided on the inner surface of the side plate 16c and around the through hole 16d so as to protrude inward by a predetermined distance. That is, the arc-shaped cover 16e is provided so as to cover the side of the large diameter portion of the conveying screw 20 near the upstream side in the toner conveying direction from the diameter changing portion 20c. The side position where the arc-shaped cover 16e is located is a position that blocks the scattering path of the toner scattered from the vicinity of the diameter changing portion 20c to the scraper 19 side by the rotation of the transport screw 20. In this embodiment, the cover 16e is provided integrally with the side plate 16c, but may be fixed to the side plate 16c as a separate member.

Next, the operation of the thus configured cleaning device will be described. The untransferred toner on the photosensitive drum 4 is scraped off by the cleaner blade 17 as the photosensitive drum 4 rotates, and the scraped toner is collected by the cleaner roller 18 and collected by the cleaner roller 18. The removed toner is scraped off by the scraper 19 with the rotation of the cleaner roller 18, and is guided to the large diameter portion 20 a of the transport screw 20.

The toner guided to the screw large-diameter portion 20a is transported downstream in the toner transport direction in accordance with the rotation of the transport screw 20, and further transported downstream via the screw small-diameter portion 20b. The toner is discharged and collected in a toner collection box (not shown) provided outside.

At this time, as shown in FIG. 5, the upper surface position of the conveyed toner 22 is inclined at approximately 45 ° clockwise about the screw axis as the conveying screw 20 rotates clockwise as shown in FIG. In the large screw diameter portion 20a, as shown in FIG. 5 (a), the upper surface position is located approximately below the screw shaft, and in the small screw diameter portion 20b, as shown in FIG. 5 (b). The upper surface is positioned so as to approximately reach the center of the screw shaft. That is, in these portions, the toner 22 is transported downstream without scattering.

On the other hand, in the diameter changing section 20c, the diameter changing section 20c acts as a resistance to conveyance, and the toner 22 stays there.
The upper surface position of the staying toner 22 is located beyond the screw axis as shown in FIG.
According to the rotation of the conveying screw 20, the toner 22
As shown by an arrow X, the particles fly toward the scraper 19. In the prior art, the scattered toner accumulates on the scraper 19 and prevents the toner from being collected by the screw large-diameter portion 20a, thereby deteriorating the cleaning function or causing scattered toner between the scraper 19 and the cleaner roller 18. As a result, the amount of the scattered toner accumulated becomes excessive, and as shown in FIG.
a causes a curl deformation, and the toner leaks out of the casing 16 from the end 19a where the curl deformation has occurred through a path indicated by an arrow Y (see FIG. 8), and the image on the machine or on the recording paper is removed. There was a problem of getting dirty.

However, in the present embodiment, as described above, the cover 1 is located at a position that blocks the toner scattering path.
6e, the toner scattered toward the scraper 19 is completely shut off by the cover 16e, collected again by the screw large-diameter portion 20a, and conveyed to the downstream side. Accumulation is prevented, and the above-mentioned problem can be solved.

FIG. 6 is a cross sectional view showing a cleaning apparatus according to another embodiment of the present invention. is there.

In this embodiment, a sheet-shaped toner seal member 23 is used instead of the cleaner roller 18 and the scraper 19 described in the previous embodiment. The toner seal member 23 is provided so that the upper end portion is close to the photosensitive drum 4 and the toner scraped off by the cleaner blade 17 is guided to the screw large diameter portion 20a.

Since such a cleaning device is also provided with a cover 16e similar to that described in the previous embodiment, the toner scattered toward the toner seal member 23 is completely blocked by the cover 16e. Is done. Accordingly, there is no accumulation of toner on the toner seal member 23, and a decrease in the cleaning function is prevented. In addition, scattered toner is accumulated between the toner seal member 23 and the photosensitive drum 4, and the accumulated amount of the scattered toner is excessive. As a result, the weak end portion of the toner seal member 23 undergoes curl deformation, and the toner leaks from the curled end portion as shown by the arrow Z and falls, thereby causing the image on the apparatus or on the recording paper to fall. Stain is also prevented. That is, the same effect as that of the above embodiment can be obtained.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say, for example, the diameter changing portion 2 of the transport screw 20 shown in FIG.
As shown in FIG. 7, the large-diameter portion and the cover 16e near the upstream side in the toner transport direction from 0c may be formed in a tapered shape tapering from the upstream side to the downstream side in the toner transport direction. In the case of such a configuration, the toner stagnation in the diameter change portion of the transport screw 20 described in the previous embodiment is reduced.
It will be performed better. Also, at least one of the large diameter portion and the cover 16e near the upstream side of the diameter change portion 20c of the transport screw 20 shown in FIG.
Similar effects can be expected even if the taper shape is tapered from the upstream side to the downstream side in the toner transport direction.

In the above-described embodiment, the cover 16e is formed in an arc shape so as to cover a necessary minimum. However, in order to completely prevent the toner from scattering on the sheet-like members 19 and 23, the diameter of the conveying screw 20 is changed. The entire periphery of the large diameter portion near the upstream side from 20c may be covered.

It is needless to say that the present invention can be similarly applied to various kinds of image forming apparatuses such as copiers, facsimile machines, printers and the like.

[0041]

As described above, in the cleaning device of the image forming apparatus according to any one of the first to third aspects, the toner staying in the portion where the diameter of the transport screw changes is scattered toward the sheet member by the rotation of the transport screw. Even so, the cover is provided on the side of the large diameter portion near the upstream side in the toner conveyance direction from the diameter change portion of the conveyance screw so that the scattering can be blocked, and the accumulation of the scattered toner on the sheet-like member can be prevented. With this configuration, it is possible to improve the cleaning function, and it is also possible to prevent the inside of the apparatus and the image on the recording paper from being stained due to the toner leaking and falling.

According to a fourth aspect of the present invention, in the cleaning device of the image forming apparatus, at least one of the large-diameter portion and the cover near the upstream side in the toner conveying direction from the diameter change portion of the conveying screw is moved from the upstream side in the toner conveying direction to the downstream side. The taper is formed so as to taper toward the tapered portion, so that the toner stagnation at the portion where the diameter of the transport screw changes is reduced, and the toner is conveyed more favorably at the portion where the diameter changes. The effect obtained can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a copying machine as an example of an image forming apparatus to which the present invention is applied.

FIG. 2 is a cross-sectional view illustrating a cleaning device according to an embodiment of the present invention.

FIG. 3 is a plan cross-sectional view illustrating a transport screw and its vicinity in FIG. 2;

FIG. 4 is an exploded perspective view showing the transport screw and its neighboring parts.

5A and 5B are views showing a state of the toner conveyed by the conveying screw, and FIG. 5A is a cross-sectional explanatory view showing a state of the toner conveyed in a large-diameter portion of the screw, and FIG. FIG. 4 is an explanatory cross-sectional view illustrating a state of the transported toner in FIG.

FIG. 6 is a cross-sectional view illustrating a cleaning device according to another embodiment of the present invention.

FIG. 7 is a cross-sectional plan view illustrating a main part of a cleaning device according to still another embodiment of the present invention.

FIG. 8 is an explanatory cross-sectional view showing a problem of the cleaning device in the related art.

FIG. 9 is a perspective view of the sheet-like member in FIG.

[Explanation of symbols]

 Reference Signs List 4 Image carrier 16 Casing (outer surface of cleaning device) 16e Cover 18 Cleaner roller 19 Scraper (sheet-like member) 20 Transport screw 20a Transport screw large-diameter portion 20b Transport screw small-diameter portion 20c Transport screw diameter change portion 22 Toner 23 Toner seal member (Sheet-shaped member)

Claims (4)

[Claims] 1. A transfer screw having a screw large-diameter portion and a screw small-diameter portion having different screw diameters, wherein the large-diameter portion is disposed in a cleaning device, and the small-diameter portion is disposed outside the device. Collecting the toner removed from the surface of the image carrier into a large-diameter portion of the transport screw via a sheet-like member disposed in the apparatus, and driving the transported screw to drive the transported screw to the large-diameter portion. In the cleaning device of the image forming apparatus which conveys and discharges through the small-diameter portion, the toner is scattered toward the sheet-like member on a side of a large-diameter portion near an upstream side in a toner conveyance direction from a diameter change portion of the conveyance screw. A cleaning device for an image forming apparatus, wherein a cleaning cover is provided. 2. A cleaning device comprising: a cleaner roller for collecting toner removed from the surface of the image carrier; and an upper end of the sheet-like member rubs against the cleaner roller to scrape off the toner collected by the cleaner roller. The cleaning device for an image forming apparatus according to claim 1, wherein the cleaning device is a scraper that guides the toner. 3. The sheet-like member according to claim 1, wherein an upper end portion of the sheet-like member is close to the surface of the image carrier, and is a toner seal member for guiding the toner removed from the surface of the image carrier to a conveying screw. Cleaning device for image forming apparatus. 4. A tapered shape in which at least one of a large-diameter portion near the upstream side in the toner conveying direction from a portion where the diameter of the conveying screw changes and a cover that blocks the toner scattering is tapered from the upstream side in the toner conveying direction to the downstream side. The cleaning device for an image forming apparatus according to any one of claims 1 to 3, wherein the cleaning device is configured as follows.