JPS61100785A - Cleaning device - Google Patents

Abstract

PURPOSE:To obtain stable cleaning action by forming the width of a scraper shorter than that of a sliding roller and the width of the sliding roller shorter than that of a cleaning blade. CONSTITUTION:The width of the cleaning blade 9 is formed longer than that of the sliding roller 10 by 3-15mm at both the ends and the width of the scraper 11 is formed shorter than that of the sliding roller 10 by 1-5mm at both the ends. In a range where the scraper 11 is abutted upon the sliding roller 10 in said constitution, the thickness of toner on the roller 10 is 30mu or less and the toner thickness on the scraper non-abutted part on both the ends is about 20mu. The excessive toner is carried by a photosensitive body up to the position of the cleaning blade 9 and slightly dispersed to the outside space 17 by the action of the edge of the blade 9. In this case, the toner is not carried up to a gap part 15 between the blade 9 and a sealing member 13.

Description

DETAILED DESCRIPTION OF THE INVENTION 11J Object of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus such as an electrophotographic copying machine that utilizes an electrostatic transfer process, and particularly to a cleaning device therefor.

(Prior art and issues to be solved) After forming a transferable toner image on the surface of a walking image carrier, this is transferred to a transfer material, and at this time, residual toner and other foreign matter remaining on the surface of the image carrier are removed. In a well-known image forming apparatus that repeats the process, it is essential to sufficiently remove residual toner and other foreign matter each time in order to obtain a stable image.

As this type of cleaning means, a cleaning blade made of an elastic material such as urethane rubber has been widely used since it has a simple structure and has an excellent toner removal function.

However, the objects to be removed from the surface of the image carrier are only the residual toner and not the residual toner. There are various types of foreign matter, such as paper that is mainly used as a paper, precipitated rosin, Merck, etc. This could have had a negative impact on the formation of painting techniques.

Furthermore, it has been difficult to sufficiently remove the above-mentioned foreign substances using the leaning blade as described above.

For this reason, as a cleaning means, in addition to the leaning blade described above, a roller made of an elastic material such as silicone rubber urethane is arranged near the cleaning blade, and the roller presses and rubs the surface of the image carrier. Proposed.

The above-mentioned elastic rubbing roller is made by coating the surface of a 7-recon sponge with solid silicone rubber, for example.
Its hardness is 20~. 40 (ASKERC constant load 500
For example, when press-contacting a rotating cylindrical image carrier, the nip width at the time of press-contact is set to 1 to 4 mm, and the circumferential speed of the rubbing roller at the contact area is set to be equal to that of the image carrier. It has been found that when the ratio is 50 to 300%, good results can be obtained in removing foreign substances as described above.

As described above, by using the cleaning blade and the elastic slider 10-ra, the function of removing residual toner on the surface of the image carrier and foreign matter in the pond is improved, but the structure of the relevant part of the cleaning device is Since the process is so complicated, there is a risk that problems may arise in the processing of toner and the like removed from the image bearing member by the blade and the rubbing roller.

To explain this with reference to FIGS. 3A and 3B, these figures are partial front views of the portion where the cleaning blade and the elastic rubbing roller are in contact with the image carrier, as seen from the image carrier side. , an elastic rubbing roller 10 with a suitable nip width 10c rubs an image bearing member (not shown) running almost parallel to the paper surface in the direction of arrow A, and one edge of the cleaning blade 9 disposed on the downstream side It is assumed that cleaning blade 9a is in pressure contact with the surface of the image carrier 0 Cleaning blade 9. A sealing material 13 is provided on the side of the rubbing roller 10 for scattering the removed toner, etc.
are arranged on both sides (only one of which is shown in the figure).

In such a structure, as shown in FIG.
(hereinafter the same applies) is larger than that of the cleaning blade, or if both are close to each other, the toner removed from the image bearing member will be transferred to the gap 1 between the side edge of the blade 9 and the sealing material 13.
There is a risk that the particles may enter the image forming apparatus 5 and further escape outside the cleaning apparatus, contaminating various parts inside the image forming apparatus.

Further, as shown in FIG. 3B, if the width of the cleaning blade 9 is larger than that of the rubbing roller 10, toner will not be sufficiently collected in the portions 16 near both ends of the blade, and the blade edge in this portion will The friction between the blade and the image carrier becomes extremely large, causing the blade to curl up, resulting in poor cleaning.

The present invention has been completed in view of these drawbacks, and the above-mentioned drawbacks can be solved by appropriately determining the widths of members related to the processing of removed toner, such as the width of the cleaning blade and the width of the rubbing roller. It is an object of the present invention to provide a cleaning device that can effectively avoid such problems.

(2) Structure of the invention (technical means 1 effect for solving the problem) In order to achieve the above object, the present invention provides a cleaning blade and an image carrier disposed on the upstream side of the blade when viewed from the direction of the running force of the image carrier. In the cleaning device, the width of the scraper is shorter than that of the rubbing roller, and the width of the rubbing roller is cleaned. It is characterized by being shorter than the blade.

With this configuration, an appropriate amount of toner, etc. removed from the surface of the image carrier is guided to both ends of the cleaning blade, and the toner is transferred to the outside of the cleaning device.
lc3g7. A stable cleaning action can be obtained by preventing the cleaning blade from scattering or becoming insufficient at both ends of the cleaning blade.

(Explanation of Embodiments) The present invention will be explained below with reference to the attached drawings in the case where the present invention is applied to a copying machine equipped with a rotating cylindrical photoreceptor. Fig. 1 shows the main parts of a copying machine to which the present invention is applied. 2 is a schematic side view of a cylindrical photoreceptor 1 that rotates in the direction of arrow A. After the surface photoconductive layer of a cylindrical photoreceptor 1 is charged by a charger 2, an optical image 3 of a document is irradiated to form an electrostatic a-image. Ru. Next, toner is supplied to the latent image from the developing device 4 to form a transferable toner image, and the toner image is transferred to a transfer material separately conveyed from a conveyance path 5 at a transfer site equipped with a transfer charger 6. .

The transfer material is then separated from the photoreceptor l by the action of the separation charger 7a and the separation roller 7b, and passes through the conveyance path 7c to the fixing site (
(not shown).

On the other hand, toner that does not contribute to transfer and remains on the surface of the photoconductor at the transfer site is contaminated with various foreign substances as mentioned above.
The cleaning device 8Vc is provided with a cleaning blade 9 for scraping off the residual toner, and furthermore, in the illustrated embodiment,
On the upstream side, there is a (flt property (f position roller 1)
0 is pressed and rubbed against the photoreceptor 1. The rubbing roller 1-7 consists of an inner layer TAB made of 7-recon sponge and an outer layer 10a made of solid silicone rubber, and has the function 1 of the structure described above.

These rubbing rollers 10. Toner and other foreign matter removed from the surface of the photoreceptor by the cleaning blade 9 adheres to and accumulates on the surface of the rubbing roller, is conveyed as the roller rotates, is scraped off by the scraper 11, and accumulates in the cleaning device, where it is further removed as needed. Accordingly, the screw conveyor 12 discharges the liquid to the outside.

In such a copying machine, in this embodiment, a cleaning blade 9. The widths of the rubbing roller 1° and the scraper 11 are set as follows.

FIG. 2 shows the relative arrangement of the three above as seen from the direction of arrow B in FIG.
The width of the scraper 11 is placed at both ends to make the width of the scraper 11 1 to 5 mm shorter than that of the rubbing roller.

With this configuration, within the range where the scraper is in contact with the rubbing roller, the thickness of the toner on the cola is less than 3.Ωμ゛, while the portions at both ends that are not in contact with the scraper are The remaining IAI toner is transported by the photosensitive VC and reaches the cleaning blade position, and by the action of the edge, it is diffused into the space 17 on both sides slightly outward. In this case, the cleaning blade 9. Toner scraping function of the scraper 11, toner scraping removal action of the rubbing roller 0,
Depending on the characteristics of the toner, etc.

By setting the width relationship of each of these members to appropriate values, the toner diffused at the blade edge is removed at that portion, and the blade and seal member 13
It is very easy to experimentally prevent the liquid from reaching the gap 15 between the two.

Cleaning blade 9. Suri-suri row 210
By determining the dimensional relationship between the scraper 11 and the scraper 11, an appropriate amount of toner can be supplied to the cleaning blade area without being removed by the rubbing/roller area, and the toner can be removed from both ends of the cleaning blade (C and V due to lack of toner). Turning etc.
In addition, it can effectively prevent the toner from escaping from the gap to the outside.

Next, the relationship between the cleaning blade width, the rubbing roller width, and the developing area width of one image area on the surface of the photoreceptor will be explained.

As is well known, the toner adhesion area supplied by the developing device 3, i.e., the development area, is made larger than the width of the transfer material, i.e., the image area, to prevent transfer leakage. A non-image area is formed on the outside of both sides of the photoreceptor, where the photoreceptor runs with some toner still attached.

On the other hand, when it comes to the rubbing roller, it is true that silicone rubber is preferred, but if there is a large amount of unreacted components in the rubber, this will leach onto the roller surface and affect the photoreceptor. It is known that this may cause deterioration of both images due to the disturbance of the electrostatic latent image and the contamination of the transfer material.To avoid such inconveniences, it is better to use urethane rubber. However, when using urethane material,
If only the above-mentioned dimensional relationship of the blade or the like in the cleaning device is sufficient, the lateral diffusion of toner by the blade edge may become insufficient.

In such a case, in addition to the above-mentioned legal relationship between each member, the width of the rubbing roller should be determined to be midway between the maximum developing and maximum image areas, so that at least part of the non-image area is It is advantageous to avoid toner starvation conditions at both ends of the blade by allowing some toner to reach the cleaning blade edge directly.

(3) Effects of the Invention The present invention provides a cleaning device for use in an image forming apparatus, including a Cleany Puffer Blade 1 elastic sliding roller for removing residual toner and other foreign matter, and a scraper for removing toner and the like from the roller.

By setting the respective widths in an appropriate relationship, toner can be supplied throughout the cleaning blade eclipse to avoid situations such as plate turning over due to toner shortage and cleaning failures caused by this, as well as to prevent excess toner from getting onto both sides of the blade. Dogs can also prevent the water from escaping outside the cleaning device, allowing a stable cleaning function to be maintained over a long period of time and contributing to obtaining high-quality images.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of the main parts of a copying machine to which the present invention is applied;
FIG. 2 is a front view of main parts showing the relative arrangement of the cleaning blade, rubbing roller, and scraper, and FIGS. 3A and 3B are partial front views showing the known relational arrangement of the cleaning blade and the rubbing roller. . DESCRIPTION OF SYMBOLS 1... Photoreceptor, 3... Developing device, 8... Cleaning device, 9... Cleaning blade, 10... Sliding roller 9.11... Scraper, 13... Seal member 15... Gap Figure 1 Figure 2 Oc

Claims (2)

[Claims] (1) It is equipped with a cleaning blade that comes into pressure contact with the surface of the image carrier, an elastic rubbing roller that rubs against the surface, and a scraper that comes into contact with the rubbing roller, the length of which is larger than the length of the rubbing roller in the axial direction. Also, in the cleaning device, the cleaning blade has a longer length when viewed in the same direction, and the scraper has a shorter length when viewed in the same direction. (2) The cleaning device according to claim 1, wherein the length of the rubbing roller in the axial direction is smaller than the maximum development area width and larger than the maximum image area width.