JPH0619380A - Cleaning device for image forming device - Google Patents

Abstract

PURPOSE:To maintain cleaning performance for a long period by making the wear resistance of a blade higher than that of a recovering roller. CONSTITUTION:A metallic blade 6 is abutted on the toner recovering roller 5, and toner 3 thereon is scraped off. The metallic blade 6 which is formed of the base stock of stainless steel SUS 304 through etching processing, in the shape of a plate, functioning as a spring, is bent in some degree so as to abut on the toner recovering roller 5. At this time, the wear resistance of the metallic blade 6 is set higher than that of the toner recovering roller 5. Therefore, the toner recovering roller 5 and the blade 6 are in uniform contact even in small contact pressure, the load of the blade is reduced, and the abrasion of both of them is reduced, as well, so that the chipping of the blade 6 and clogging with the toner can be prevented, and excellent cleaning performance is maintained over a long period. Moreover, since the abrasion of the blade 6 is lessened, a complex blade abrasion detecting means can be dispensed with.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for an image forming apparatus using an electrophotographic process.

[0002]

2. Description of the Related Art Since the conventional cleaning device for an image forming apparatus is mostly the same as the embodiment of the present invention,
This will be described with reference to FIG. It includes a brush roller 4 for applying a bias voltage from a bias power source (not shown) to remove the residual toner 3 on the image carrier 2;
While contacting and rotating with the brush roller 4 from the toner 3
Toner collecting roller 5 for collecting toner, and toner collecting roller 5
And a blade 6 for scraping off the toner on the toner collecting roller 5, the toner collecting roller 5 being made of a metal roller such as stainless steel, and the blade 6 being a rubber using urethane rubber or fluororubber. It consists of a blade. Further, a metal toner collecting roller 5 provided with an electrically insulating layer such as resin on the surface thereof, or a toner collecting roller 5 made of silicon rubber having a rubber hardness of 45 ° to 50 ° is used. This is because the abrasion resistance of the toner recovery roller 5 is equal to or greater than the abrasion resistance of the blade 6. Further, there is a device using a scraping member of sponge or felt that comes into surface contact with the toner collecting roller 5. Further, in order to prevent problems due to wear of the blade 6, there is a blade wear amount detecting means provided. Reference numeral 9 denotes a casing of the cleaning device 1, 10 denotes a holder, 11 denotes a toner transport coil, 12 and 13 denote driven rollers, and 14 denotes a counter roller.

[0003]

In the conventional cleaning device as described above, a metal roller such as stainless steel is used for the toner collecting roller, and a rubber blade using urethane rubber or fluororubber is used for the blade,
Further, a metal toner collecting roller provided with an electrically insulating layer such as resin on the surface thereof, or the toner collecting roller 5 having a rubber hardness.
If the wear resistance of the toner recovery roller is equal to the wear resistance of the blade,
Also, since it is large, the blade is liable to be worn or chipped, and the one using a scraping member of sponge or felt that comes into surface contact with the toner collecting roller instead of the rubber blade is clogged with toner on the sponge or felt. Occurs, the life is shorter than that of the rubber blade, cleaning failure of the toner recovery roller is likely to occur, good cleaning performance cannot be maintained for a long period of time, and blade wear amount detection means for detecting blade wear is provided. In order to detect a very small amount of wear (about 10 to 50 μm), it is necessary to improve the accuracy of parts, the detection circuit becomes complicated, and it is not for maintaining the life of the blade for a long time. There's a problem.

Therefore, an object of the present invention is to solve the above problems, to prevent blade abrasion and chipping from occurring, to prevent blade clogging, and to provide blade abrasion amount detection means. It is an object of the present invention to provide a cleaning device capable of maintaining good cleaning performance over a period of time.

[0005]

In order to achieve the above-mentioned object, the present invention according to claim 1 is at least as follows.
A brush roller that removes residual toner on the image carrier, a toner collection roller that contacts the brush roller to collect toner from the brush roller, and a contact roller that contacts the toner collection roller and that is located on the toner collection roller. In a cleaning device of an image forming apparatus having a blade for scraping off toner, the abrasion resistance of the blade is higher than the abrasion resistance of the toner collecting roller.
According to a second aspect of the present invention, in the first aspect of the invention, the toner collecting roller is made of a soft member. According to a third aspect of the invention, in the second aspect of the invention, the soft member is made of urethane foam. According to a fourth aspect of the invention, in the first aspect of the invention, the blade is made of metal. According to a fifth aspect of the invention, in the fourth aspect of the invention, the metal blade is composed of a plate-shaped spring member that is elastically deformed by contact with the toner recovery roller. According to a sixth aspect of the invention, in the fourth or fifth aspect of the invention, the metal blade is electrically insulated from the housing. According to a seventh aspect of the present invention, in the first aspect of the present invention, the toner collecting roller has a Teflon coating on the cored bar, and the blade is a plate-shaped spring member that is elastically deformed by contact with the toner collecting roller. is there.

[0006]

According to the present invention as described above, in the cleaning apparatus as described above, the abrasion resistance of the blade is greater than the abrasion resistance of the toner collecting roller, and the blade edge is Clean with less wear. According to a second aspect of the present invention, in the first aspect of the invention, the toner recovery roller is made of a soft member, and the third aspect of the invention is the second aspect of the invention, in which the soft member is made of urethane foam. Cleaning is performed by uniformly contacting the roller and the blade with a small contact pressure. According to the invention of claim 4, in the invention of claim 1,
Since the blade is made of metal, it is cleaned for a long period of time without causing abrasion or chipping and toner clogging. According to a fifth aspect of the present invention, in the fourth aspect of the invention, the metal blade is composed of a plate-shaped spring member that elastically deforms by contact with the toner collecting roller, and the toner collecting roller and the blade are in uniform contact with each other with a small contact pressure. Perform cleaning. According to a sixth aspect of the invention, in the fourth or fifth aspect of the invention, the metal blade is electrically insulated from the casing, and the bias potential of the toner collecting roller does not leak to the casing. According to a seventh aspect of the present invention, in the first aspect of the present invention, the toner collecting roller has a Teflon coating on a core metal, and the blade is a plate-shaped spring member that is elastically deformed by contact with the toner collecting roller. The toner collecting roller and the blade come into contact with each other with a small friction coefficient and a contact pressure to perform cleaning.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In this embodiment shown in the drawings, the same parts as those of the conventional one are referred to by the same reference numerals, and the description thereof will be omitted.

An embodiment of the present invention is shown in FIGS. In FIG. 1 showing a first embodiment of the present invention, a toner collecting roller 5 comprises a metal cored bar 7 and a urethane urethane soft layer 8 formed on the outer peripheral surface of the metal cored bar 7, and the soft layer 8 has a rubber hardness of 40.
The resistivity is 10 ² to 10 ⁹ Ωcm at about 80 °. The thickness is preferably 0.5 to 1 mm, but it is required to be 4 to 10 mm in order to increase the electric resistance of the roller itself to some extent. The metal blade 6 contacts the toner collecting roller 5, and the toner 3 on the toner collecting roller 5 is scraped off. This metal blade 6 is made of stainless steel SUS304 with a thickness of 0.1 mm.
It is formed by an etching process, and has a plate-like shape and spring properties. Then, the metal blade 6 is bent to some extent and brought into contact with the toner collecting roller 5. Contact pressure is 5-50gf / cm
However, if it is smaller than this range, cleaning failure due to partial poor adhesion tends to occur, and if it is larger than this range, the amount of abrasion of the toner collecting roller 5 increases. Because. With such a configuration, the wear resistance of the metal blade 6 is greater than the wear resistance of the toner collecting roller 5, and the toner collecting roller and the blade are evenly contacted with each other even with a small contact pressure. The load can be reduced, the wear of both is reduced, the blade is not chipped, and the toner is not clogged, and good cleaning performance is maintained for a long period of time. Further, since the amount of blade wear is reduced, it is not necessary to provide a complicated blade wear amount detection means.

In order to keep the metal blade 6 and the casing 9 of the cleaning device 1 electrically insulated, a resin spacer is used.
15 is provided between the blade mounting portion 16 and the blade holding member 17 of the housing 9, the blade mounting portion 16 and the blade holding member 17 are fixed with polybis 18, and the blade holding member 17 and the upper holder 10 In the same manner, the resin holder 15 and the holder 10 are also attached via the resin spacer 15 and the polybis 18
The holder 10 and the housing 9 are electrically insulated from each other, and the left end of the holder 10 in FIG. 1 is formed so as not to contact the upper end of the metal blade 6. Installed on. The reason why the metal blade 6 is electrically insulated in this way is to prevent the bias current applied to the toner collecting roller 5 from leaking.

A metal blade 6 according to a second embodiment shown in FIG.
Is made of a stainless steel plate having a plate thickness of 1.5 mm, and is formed into a shape that is bent at a substantially right angle. For fixing the same, an insulating sleeve 19 is provided on the bent horizontal portion of the metal blade 6 in FIG. It is inserted into the mounting hole 22 and fixed to the blade mounting portion 16 with a screw. In this way, the metal blade 6 is electrically insulated from the housing 9, and the metal blade 6 and the end of the holder 10 are electrically insulated from each other with a gap or an electrical insulator interposed therebetween. Other than that, there is no difference from the first embodiment.

The edge portion of the lower end portion of the bent vertical portion of the metal blade 6 in FIG. 2 is used by directly digging it into the surface of the soft layer 8 of the toner collecting roller 5. The amount of bite is set to 0.2 to 0.3 mm in the direction normal to the cylindrical surface. If it is smaller than this, the metal blade 6 and the toner collecting roller 5 are likely to come into non-uniform contact. The surface of the collecting roller 5 will be destroyed.

In a third embodiment shown in FIG. 3, the core metal 7 of the toner collecting roller 5 is provided with a coating 20 of a Teflon type high resistance heat shrinkable tube having a film thickness of 500 μm, and the metal blade 6 is a metal leaf spring. And make it a resin holder with electrical insulation
There is no difference from the first embodiment except that it is attached to No. 21. .

FIG. 4 shows the comparison data of the running test between the third embodiment and the conventional apparatus. For this test, an FT9100 copying machine manufactured by Ricoh Co., Ltd. was used, S represents the amount of wear of the metal blade 6 in the same direction as the normal line of the toner recovery roller 5, and t represents the amount of decrease in the film thickness of the Teflon coating 20, The film thickness of the coating 20 before the start of the test is 500 μm. The test result is
In the conventional device, a partial cleaning defect (marked with Δ) occurs on the toner recovery roller 5 after copying about 400,000 sheets, and with 500,000 copies, a vertical black streak-shaped cleaning defect (marked with ×) is also present on the image. )There has occurred. On the other hand, according to the apparatus of the third embodiment, the cleaning failure on the toner recovery roller 5 did not occur even after 500,000 sheets, and the cleaning failure occurred on the image for the first time after copying 700,000 sheets. This is because the amount of decrease in the film thickness of the Teflon coating 20 on the toner recovery roller 5 is large and the resistance value is decreased, so that the potential difference between the toner recovery roller 5 and the brush roller 4 cannot be maintained. . Even at this stage, the toner collecting roller 5
The above cleaning failure did not occur.

[0014]

The present invention is as described above, and the invention of claim 1 is, at least, a brush roller for removing residual toner on the image carrier, and the brush roller abutting against the brush roller. A toner collecting roller for collecting toner from the
In a cleaning device of an image forming apparatus having a blade that abuts on the toner collecting roller and scrapes off the toner on the toner collecting roller, the abrasion resistance of the blade is made larger than the abrasion resistance of the toner collecting roller. Therefore, there is an effect that the blade edge is less worn and good cleaning performance can be maintained for a long period of time without providing a complicated wear detecting means. According to the invention of claim 2, in the invention of claim 1, since the toner collecting roller is made of a soft member, the toner collecting roller and the blade are brought into uniform contact with each other with a small contact pressure, and the load of the blade can be reduced. There is an effect that abrasion is reduced and good cleaning performance can be maintained for a long period of time. According to the invention of claim 3, in the invention of claim 2, since the soft member is made of urethane foam, it is easy to mold and can be manufactured at low cost, and its resistance value is adjusted from insulation to high resistance to low resistance by adjusting the content. Can be controlled, and the toner recovery roller and the blade can evenly contact each other with a small contact pressure, the load on the blade can be reduced, the wear of both can be reduced, and good cleaning performance can be maintained for a long period of time. is there. According to the invention of claim 4, in the invention of claim 1, since the blade is made of metal, it is possible to perform good cleaning for a long period of time without causing wear or chipping and without causing clogging of the blade. The effect is that you can do it. According to a fifth aspect of the invention, in the fourth aspect of the invention, the metal blade is composed of a plate-shaped spring member that is elastically deformed by contact with the toner recovery roller, and the toner recovery roller and the blade are contacted uniformly with a small contact pressure. As a result, it is possible to reduce the abrasion of the toner collecting roller and to perform good cleaning for a long period of time. According to a sixth aspect of the invention, in the fourth or fifth aspect of the invention, the metal blade is electrically insulated from the casing, and the bias potential of the toner collecting roller does not leak to the casing through the metal blade. The advantages are that the bias current to the toner collecting roller can be reduced, the power source can be downsized, and the bias potential of the toner collecting roller can be easily maintained. According to a seventh aspect of the present invention, in the first aspect of the present invention, the toner collecting roller has a Teflon coating on a core metal, and the blade is a plate-like spring member that is elastically deformed by contact with the toner collecting roller. Since the collecting roller and the blade come into contact with each other with a small friction coefficient and contact pressure, the amount of wear between the blade and the toner collecting roller is small, and good cleaning can be performed for a long period of time without causing wear or chipping. There is.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a first embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view showing a second embodiment of the same.

FIG. 3 is a schematic vertical sectional view showing a third embodiment of the above.

FIG. 4 is a table showing comparative data of running tests between the third embodiment and the conventional device.

[Explanation of symbols]

 1 Cleaning Device 2 Image Carrier 3 Toner 4 Brush Roller 5 Toner Collection Roller 6 Blade 7 Core Bar 8 Soft Layer 9 Housing 10 Holder 15 Spacer 16 Blade Mounting Part 17 Blade Holding Member 18 Polybis 19 Insulation Sleeve 20 Teflon Coating 21 Resin Holder 22 Mounting hole

Claims (7)

[Claims] 1. A brush roller for removing residual toner on an image carrier, a toner collecting roller for contacting the brush roller to collect toner from the brush roller, and an abutting member for contacting the toner collecting roller. In a cleaning device of an image forming apparatus having a blade for scraping off toner on the toner collecting roller, the abrasion resistance of the blade is larger than the abrasion resistance of the toner collecting roller. Cleaning device. 2. The cleaning device for an image forming apparatus according to claim 1, wherein the toner collecting roller is made of a soft material. 3. The cleaning device for an image forming apparatus according to claim 2, wherein the soft member is made of urethane foam. 4. The cleaning device for an image forming apparatus according to claim 1, wherein the blade is made of metal. 5. The cleaning device for an image forming apparatus according to claim 4, wherein the metal blade is a plate-shaped spring member that is elastically deformed by contact with the toner recovery roller. 6. The cleaning device for an image forming apparatus according to claim 4, wherein the metal blade is electrically insulated from the casing. 7. The cleaning device for an image forming apparatus according to claim 1, wherein the toner collecting roller has a Teflon coating on a core metal, and the blade is a plate-like spring member which is elastically deformed by contact with the toner collecting roller.