JPS6290687A - Cleaning device - Google Patents

Abstract

PURPOSE:To prevent a protection layer from damaging by supplying various hard particles from a cleaning roller to an image carrier. CONSTITUTION:The elastic cleaning roller 4 made of silicon rubber is pressed against the surface of the photosensitive body 2 on the upstream side of a cleaning blade 3 in the running direction of the photosensitive body and then rubbed against it by a proper driving source at a proper relative speed. Further, a scraper 5 is arranged abutting on the cleaning roller 4. This scraper 5 scrapes toner scraped off with the cleaning blade 3, toner removed with the cleaning roller 4, and other foreign matter and falls them. Then, they are discharged by a screw conveyor 7. Thus, irregularity in coating, i.e. the grinding irregularity of the surface protection layer of the image carrier is eliminated to obtain an invariably stable cleaning function.

Description

Detailed Description of the Invention (1) Purpose of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus that uses an electrostatic transfer process, such as an electrophotographic copying machine or a printer, and particularly to a cleaning device therefor. .

(Prior art and problems to be solved) After transferring the toner image formed on the surface of a moving image carrier to a sheet-like transfer material such as paper, the toner image formed on the surface of the moving image carrier is transferred. An image forming apparatus configured to repeat the process of transferring toner to a sheet-like transfer material such as paper and then removing residual toner remaining on the surface of the image carrier using a cleaning means is conventionally well known.

A cleaning blade made of an elastic material such as rubber is used as a cleaning means in this type of image forming apparatus.
It is widely used because it is simple in structure and has an excellent toner removal effect. However, on the other hand, the cleaning blade does not remove the fused toner that solidifies and adheres to the surface of the image carrier.
It has been found that they are not always suitable for removing foreign matter such as paper dust, rosin, precipitates such as talc, and corona products.

In order to compensate for the disadvantages of leaning blades,
A cleaning roller made of an elastic material such as silicone rubber has been proposed so as to rub against the surface of the image carrier to remove the various foreign substances mentioned above.

The elastic cleaning roller as described above is disposed within the cleaning device, and the scraper is placed in contact with the elastic cleaning roller. As the roller rotates, the aforementioned foreign matter, toner, etc. that are rubbed off the image carrier fall and accumulate in the waste toner storage area of the cleaning device, and some of the toner is also scraped onto the roller surface with a scraper. It is common to coat the surface of the image carrier and rub the surface of the image carrier with the coated surface.

However, with such a configuration, when coating the cleaning roller with toner, not only toner but also the aforementioned foreign matter is mixed in, and this enters between the scraper and the roller and damages the scraper's knee joint and roller surface. There is a risk of damage to the product.

Naturally, when such a situation occurs, local changes occur in the thickness of the toner coating on the surface of the cleaning roller, resulting in uneven coating. Coating unevenness can be as large as 100 mm, and when this happens, the rubbing action between the cleaning roller and the image carrier becomes stronger in some areas, and the magnetic material in the toner and the abrasive agent added to the toner in small amounts become stronger. A part of the surface protective layer of the image carrier is ground by the hard particles formed by the agglomeration of the particles, causing uneven scratching.

In such a state, the effective amount of light reaching the photoconductive layer inside the protective layer will vary due to refraction and interference of the incident light that is applied to this surface to form an electrostatic latent image, and this will cause density unevenness in the image. This may result in significant deterioration of image quality.

The present invention has been made in order to cope with such a situation, and the thickness of the toner coating on the surface of the elastic cleaning roller that rubs against the image bearing member is smoothed as much as possible to prevent the occurrence of the above-mentioned defects. It is an object of the present invention to provide a cleaning device which is effective for avoiding kudzu, provides a stable cleaning action over a long period of time, and forms high-quality images.

(2) Structure of the invention (technical means for solving the problem and its operation) In order to achieve the above object, the present invention includes an elastic cleaning roller as a cleaning means, and the present invention provides an elastic cleaning roller as a cleaning means. The scraper is characterized in that the contact edge side of the scraper that contacts the roller is formed in a sawtooth shape, and that the surface portion and the edge portion of the scraper are configured to come into pressure contact with the surface of the cleaning roller.

With this configuration, it is possible to prevent the above-mentioned coating unevenness, and thus to prevent uneven scratching of the surface protective layer of the image carrier, and to always perform a stable cleaning function.

(Description of Embodiments) An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a case in which the present invention is applied to a copying machine equipped with a rotating cylindrical image carrier 2 (photoreceptor), and a cleaning blade 3 is installed close to and parallel to the photoreceptor. The installed cleaning device 1 is profitable.

The photoreceptor is assumed to rotate in the direction indicated by the arrow in the figure, and around it, as is well known, a -order charger, an image signal applying means, a developing device, a transfer means, and other image forming members are arranged. has been done. Note that since these are not directly related to the present invention, explanations thereof will be omitted.

An elastic cleaning roller 4 made of silicone rubber is located upstream of the cleaning blade when viewed in the direction of travel of the photoreceptor.
is in pressure contact with the surface of the photoreceptor 2, and is rubbed at an appropriate relative speed by an appropriate drive source (not shown).

A scraper 5 is attached to the cleaning roller and scrapes off the toner scraped off by the cleaning blade 3, the toner removed by the cleaning roller 4, and other foreign matter, and drops the toner downward. It shall be discharged to the outside.

The cleaning roller can be made of silicone rubber, urethane rubber, etc., and has a surface hardness of 40 to 40 according to JIS surface hardness.
60@, surface roughness is 25 liters or less, and pressure on the photoreceptor is 1
．． It is 0 to 2.0 kg. Further, the rotation of the cleaning roller is 50 to 99.5% to 100% of that of the photoreceptor.
A preferable range is 5 to 120%.

As shown in FIG. 2, the edge of the scraper 5 that comes into contact with the cleaning roller is formed into a sawtooth shape, and the scraper 5 is arranged so that the intermediate inclined portion 5a of each tooth portion, shown by hatching, comes into contact with the surface of the cleaning roller. It is. In other words, the surface of the scraper and the edge are alternately in contact with the cleaning roller.

First, the scraper is usually brought into pressure contact with the cleaning roller by supporting both ends of the scraper. However, in this case, the central portion of the scraper inevitably becomes separated from the cleaning roller. However, by configuring the portion of the scraper that contacts the roller as described above, both end portions of the scraper also come into surface contact with the cleaning roller, resulting in increased resistance. This makes it difficult for the scraper to bite into the cleaning roller, which prevents the scraper from curving accordingly.As a result, the contact pressure of the scraper against the cleaning roller is made uniform, and damage to the cleaning roller due to edges can be prevented.

Further, the edge on which the scraper scrapes off foreign matter adhering to the surface of the cleaning roller is oblique to the running direction of the roller. This makes it easy to remove foreign substances,
This is also advantageous in preventing damage to the rollers.

As shown in FIG. 2, the scraper 5 has a buffer pad 9
The scraper 5 is supported by a support member 6 via a drive source 8 such as a plunger, which causes the scraper 5 to reciprocate in the axial direction of the cleaning roller with an appropriate stroke. Reference numeral 9 biases the support member to one side, and cooperates with the drive source 8 to reciprocate the support member in the left-right direction in the figure.

With this structure, the surface of the cleaning roller alternately contacts the surface and edge of the scraper, so that local wear does not occur.

If the angle of the edge of the scraper is large, there will be no difference in effectiveness from the well-known straight edge, but if it is too small, the roller may be damaged at the tip, the foreign matter removal function of the two-slanted edge will be reduced, and the roller Since this has a negative effect on the effect of equalizing the contact pressure due to the above-mentioned surface contact, it is preferable to set it to about 120@.

Further, it is preferable that the reciprocating stroke of the scraper is equal to or larger than the pitch of the serrated edges. Furthermore, add a buffer pad to 1. %'l-, it is possible to prevent the scraper from biting into the cleaning roller and causing scraping defects at the time of startup.

(3) Effects of the Invention Since the present invention has the configuration described above, in a cleaning device equipped with a sleeve cleaning roller that rubs the surface of an image carrier, various hard particles are transferred from the cleaning roller to the image carrier. It can be effectively prevented from being delivered to the body and damaging its protective layer. As a result, the life of the image carrier can be greatly extended, which greatly contributes to stably obtaining high-quality images over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of a cleaning device equipped with an elastic cleaning roller according to the present invention, and FIG. 2 is a front view showing the relationship between the cleaning roller and a scraper. DESCRIPTION OF SYMBOLS 1...Cleaning device, 2...-Photoreceptor, 4-Fist elastic cleaning roller, 5...Scraper, 6...
・Supporting member, 9.Φ.Buffer pad.

Claims (1)

[Scope of Claims] A cleaning device including an elastic cleaning roller that rubs against the surface of an image carrier, and a scraper that comes into pressure contact with the cleaning roller, wherein an edge of the scraper is formed into a serrated shape, and the serrated portion A device characterized in that a surface portion and an edge portion of an intermediate portion of the cleaning roller are alternately brought into contact with the cleaning roller.