JPS6031174A - Cleaning device - Google Patents

Abstract

PURPOSE:To maintain stably a function of a cleaning blade extending over a long period of time by providing a toner passing through-hole formed on a scraper plate contacting by pressing to a magnetic roller, on plural stages, or providing plural kinds of toner selecting through-holes. CONSTITUTION:A large hole 6a is provided in a row in the vicinity of the fitting side on a suitable place of a cleaning device of a scraper plate 6, and a small hole 6b is provided in a row on the side contacting to a magnetic roller. In this state, a fine one of a toner scraped by a cleaning blade passes through the scraper plate from the small hole 6b, etc. and is carried immediately, and that which has become like a lump or a mixed comparatively large paper piece, etc. cannot pass through the small hole, pass through the large hole 6a after rolling in the space, are carried by getting on the surface of a fine particle toner which has passed through the small hole along the magnetic roller, and this part is removed exactly by a tuft cutting blade 4, goes into a storing part of the left and discharged by a screw converyor 5. Accordingly, the tuft cutting blade, the magnetic roller, etc. are not damaged by impurities, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for an image forming apparatus that uses an electrostatic copying process, such as an electrostatic copying machine or a printer.

After forming a transferable toner image on the surface of a moving photoreceptor and transferring the image to a transfer machine, residual toner on the surface of the photoreceptor that did not contribute to transfer is removed, and the toner image formation and transfer process are repeated again. In order to remove residual toner, a cleaning blade made of an elastic material such as rubber is brought into pressure contact with the surface of the photoreceptor to scrape off the residual toner. Due to its excellent scraping function,
It is already widely used.

In this type of cleaning device, a magnetic roll is arranged upstream of the cleaning blade, and the scraped toner is attracted to the magnetic roll and conveyed to the storage area, and the toner is collected in the storage area as needed. Conventionally, cleaning apparatuses have been known in which the toner is discharged from the cleaning apparatus by an appropriate means such as a screw conveyor.

A cleaning device with such a configuration reduces friction with the photoconductor blade because the required amount of toner is small and the amount of residual toner is also small when producing small-sized prints or prints with a large amount of white material, for example. If the coefficient becomes large, the grade will be reversed as shown by the symbol 2', and the cleaning action will no longer function, and there is a risk of damaging the magnetic roll. A system configured as shown in has been proposed.

To briefly explain this with reference to the figure, a cleaning device 1o is disposed in an image forming apparatus (not shown) in close proximity to a rotatable cylindrical rotating body 1 arranged to extend perpendicularly to the plane of the paper. The cleaning device is formed into a cylindrical shape and is arranged substantially parallel to the photoreceptor, to which a cleaning blade 2 is attached as shown.

A transferable image formed by a charging, exposing, and developing section (not shown) disposed around the photoreceptor 1 is transferred to a transfer material (not shown) at the next transfer site, and the toner that did not contribute to the transfer is transferred to a transfer material (not shown) at the next transfer site. is the residual toner T in the cleaning device 10.
When the cleaning blade 2 reaches the area, the toner is scraped off by the cleaning blade 2, and the scraped toner is conveyed to a storage section by the magnetic roller 3 and discharged to the outside of the cleaning device by the screw conveyor 5.

In such a device, in order to avoid the aforementioned drawback that the amount of residual toner reaching the blade is too small, the magnetic roller 3 is provided with a large number of through holes as shown in the second figure. At the same time, a scraper plate 6 having a magnetic roller 6a is disposed, and an ear cutting blade 4 is formed in the toner conveyance path by the magnetic roller, so that the scraped toner passes through the through hole of the scraper plate 6 and reaches the ear cutting blade 4. A part of the toner proceeds to the storage part and is discharged, and a part of the toner regulated by the blade 4 is maintained in a state where it is accumulated to some extent on the upstream side of the cleaning blade 2 in the vicinity of the photoreceptor again. Configure it as follows.

With this configuration, even if the amount of residual toner reaching the cleaning device is small depending on the condition of the document as described above, a certain amount of toner is always present on the upstream side of the cleaning blade 2. Disadvantages due to toner shortage, such as, can be avoided.

However, with this configuration, in FIG. 1, the photoreceptor 1. Magnetic low 23. Cleaning blade 2. The toner accumulated in the space surrounded by the scraper plate 6 tends to move slowly, and for this reason, the toner newly scraped off by the cleaning blade 2 passes directly through the surface of the accumulated toner. and was transported through the hole 6a of the scraper plate 6,
Old toner tends to remain stuck around the magnetic roller.

For this reason, the magnetism of the toner in this area becomes cloth and loses its fluidity, and there is a risk that the toner may fall off the magnetic roller and scatter into the device, staining the transfer machine, and may also accumulate in the space. It was impossible to avoid the defect that the toner solidified and clogged the hole 6a of the scraper plate 6, resulting in poor cleaning.

The present invention has been made in view of the current situation, and includes a plurality of through-holes formed in a scraper plate that is in contact with a magnetic roller for through-holes for passing through toner, and scraped-off toner is removed by forming through-holes in multiple stages. By arranging multiple types of through-holes for sorting toner in the path through which the toner is conveyed, the toner replacement of the magnetic roller roller is facilitated and the above-mentioned surface defects are eliminated.
Furthermore, the present invention provides a cleaning device capable of selectively removing minute pieces of paper, solidified toner blocks, etc. mixed in toner.

3 to 5 are partial plan views showing the structure of the scraper plate used in the present invention, and the one shown in FIG. Large holes 6a are arranged in a row, and small holes 6b are arranged in a row on the side that contacts the magnetic roller. FIG. 4 also shows that the scraper plate 6 has an open part 6C extending almost the entire length of the scraper plate 6 on the side to be attached to the cleaning device, and a large number of comb-shaped protrusions are formed on the magnetic roller side, and a large number of small holes are formed in between. A gap 6d is formed therein. Furthermore, FIG. 5 shows that the cleaning device is mounted by arranging a number of tapered triangular holes 6e on the side and making small holes 6f in the scraper plate on the side of the magnetic roller. be.

In all of these, it is immediately clear from the figure that the scraper plate 6 is attached to the cleaning device by making the area of the penetrating part larger in the side part and smaller in the vicinity of the opposite edge. It is common in

FIG. 6 is a diagram showing the operation when using a cleaning device equipped with such a spacer plate 6, and its configuration is basically the same as that shown in FIG. The same reference numerals are given to the parts, and the explanation thereof will be omitted.

In the figure, the residual toner T conveyed on the photoconductor rotating in the direction of arrow A is scraped off by the cleaning blade 2, but at this time, the photoconductor 1. Magnetic roller 3. Cleaning blade 2. It is assumed that a certain amount of toner is always accumulated in the space surrounded by the scraper plate 6 and the like.

Fine pieces of toner scraped off by the cleaning blade are immediately conveyed through the small holes 6b etc. through the souffle (7)-Paper plate, but lumps or relatively large pieces of paper mixed together are transported. After being unable to pass through the small hole, it moves around in the space, passes through the large hole 6a, and is conveyed along the magnetic roller on the surface of the fine toner that has passed through the small hole, and this part is cut into ears 9. blade 4
is reliably removed, enters the storage section on the left side of the figure, and is discharged by the screw conveyor 5.

Therefore, among the scraped toner and foreign matter, large particles of toner and foreign matter are constantly removed and the cleaning action is performed, so that only fine toner particles are always transported to the vicinity of the magnetic magnet. Therefore, there is no risk of dripping, ear cutting blades, magnetic rollers, etc. being damaged by foreign objects.

FIG. 7 shows another embodiment of the present invention, in which the photoreceptor 1. The same reference numerals are given to the parts of the cleaning device 10 that correspond to those shown in FIG. 1, and a description thereof will be omitted.

In this device, the scraper plate 6 that acts (8) on the magnetic roller 3 may have a configuration as shown in FIG. A sieve plate 7 is disposed at a position such that the other edge thereof is close to the surface of the magnetic roller. The sieve plate 7 is formed by forming a large number of small holes of appropriate size in a plate body, as part of its structure is shown in FIG.

With such a configuration, lumps or foreign substances mixed in the toner conveyed along the surface of the magnetic roller through the scraper plate 6 fall onto the screw conveyor 5 side by the sieve plate 7. Only the fine particles will return to the photoreceptor, so
The same effect as that shown in FIG. 6 can be achieved.

As explained above, the cleaning device according to the present invention constantly removes lumps or impurities that are not included in the residual toner or is gradually formed, and also removes fine particles on the upstream side of the scraping end of the cleaning blade. Since only toner is collected, there are problems such as contamination of various parts of the device due to toner dripping, clumpy toner particles, accumulation of foreign matter, clogging of the scraper plate due to growth, etc. It is possible to avoid drawbacks such as poor cleaning and maintain the function of the cleaning blade stably over a long period of time even when making small size copies or copies with many white areas.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an outline of the configuration of a known cleaning device, FIG. 2 is a partial plan view showing a scraper plate used in the device shown in FIG. 1, and FIGS. 3 to 5 are 6 is a side sectional view showing the cleaning device according to the present invention; FIG. 7 is a side sectional view showing another embodiment of the present invention; FIG. FIG. 8 is a partial plan view of a sieve plate used in the apparatus shown in FIG. 7. 1. Photoreceptor, 2. Cleaning blade, 3. Magnetic roller, 4. Ear cutting blade, 6. Scraper plate, 7. Sieve plate, 10. Cleaning device. Applicant Canon Co., Ltd. (11)

Claims (2)

[Claims] (1) A cleaning device for removing residual toner on the surface of a moving image carrier, a device for conveying the removed toner, and a means for bringing a portion of the conveyed toner back to the vicinity of the cleaning device. A cleaning device for an image forming apparatus, the cleaning device comprising: a means for sorting toner conveyed by the conveying means. (2) The cleaning according to claim 1, wherein the toner sorting means is a scraper plate having a small-area toner passing section on a side closer to the conveying means and a large-area toner passing section on a far side. Device.