JPS63129381A - Cleaning device - Google Patents

Abstract

PURPOSE:To fully achieve a foreign matter removing function and to always attain stable cleaning action irrespective of the state of an original by isolating a scraper from a cleaning roller at least once in the operation of the cleaning roller. CONSTITUTION:Due to the turn of a roller, toner that a cleaning blade 3 and the cleaning roller 4 remove is conveyed, and arrives at the scraper 5. The toner is scraped by the scraper 5, comes in a toner storage part, and discharged to the outside of the titled device by means of a conveyance screw 6. The scraper 5 is isolated from the roller 4 at least once while the cleaning roller is operating. Thus the part of the toner remains in the cleaning roller, and comes in a press-contact part between the roller and the photosensitive body. Hence a satisfactory toner layer is formed on an original rich in white base, whereby a desired grinding action is executed. Even after an original is copied many times, their quality is not deteriorated.

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 recording process, such as an electrostatic copying machine and a printer, and particularly to a cleaning device for the same. be.

(Prior art and solution nabe, gI!! title) An optical image of an original is projected onto the surface of a charged image carrier to form an electrostatic latent image corresponding to the original on the surface, and this is transferred to a developer (hereinafter referred to as toner). Image forming apparatuses that continuously perform the steps of applying a toner image to form a transferable toner image and transferring the image to a sheet-like transfer material such as paper are conventionally well known.

In such an image forming apparatus, in preparation for the next step, it is necessary to sufficiently clean residual toner that does not contribute to transfer and remains on the surface of the image carrier at a post-transfer position.

In order to remove the residual toner, a cleaning blade made of an elastic material such as rubber, an elastic cleaning roller, or the like is brought into contact with the image carrier and rubbed against the image carrier to remove the residual toner. It is not only toner that adheres to the body surface, but in the current situation where paper is used as a transfer material in almost all cases, there are also fine paper dust and other foreign substances generated from the paper that is the transfer material. On the other hand, the cleaning blade has an excellent toner removal function, but is not very effective against paper dust, etc., and the cleaning roller forms a thin layer of toner on its surface and uses the abrasive action of this to remove toner other than toner. This removes paper dust and other foreign substances, so if you continue to perform image forming operations on originals that have many blank areas with no toner attached, the amount of toner present on the surface of the image carrier will become too small, especially when the above-mentioned problem occurs. The formation of a single layer of toner on the cleaning roller becomes insufficient, and foreign matter such as paper dust on the image carrier cannot be sufficiently removed. For this reason, when a large number of originals with many white backgrounds are repeatedly copied, paper dust and the like gradually accumulate on the surface of the image carrier, resulting in deterioration of image quality such as blurred images.

In order to avoid such drawbacks, conventional techniques have been used to prevent toner shortage by allowing a small amount of toner to be deposited on areas other than the latent image area during development on the surface of the image carrier corresponding to the document. Although some methods have been proposed to compensate for this, such a method wastes toner, requires an additional mechanism to control the timing of toner adhesion, and is not used unnecessarily. Since the image bearing member is charged and neutralized, its life is adversely affected, which is undesirable.

The present invention has been made to deal with such a situation, and does not require any particularly complicated accompanying mechanisms or control means.
It is an object of the present invention to provide a leaning device that can fully exhibit the foreign matter removal function of an elastic cleaning roller and always perform a stable cleaning action regardless of the condition of the document.

(2) Structure of the Invention In order to achieve the above object, the present invention uses an elastic cleaning roller, removes the removed toner with a scraper that is in contact with the roller, and forms a thin layer of toner on the roller surface. The cleaning device configured as above is characterized in that the scraper is separated from the roller at least once during the operation of the roller, and the toner adhering to the roller is directly fed to the pressure contact portion with the image carrier. That is.

With this configuration, there is no need to increase the total amount of toner consumption, and there is no need to particularly precisely control the timing and amount of toner to be applied, so that a sufficient amount of toner can always be applied to the pressure contact area between the image carrier and the cleaning roller. of toner can be supplied.

(Description of Embodiments) FIG. 1 is a side view of the main parts of an embodiment in which the present invention is applied to a copying machine equipped with a cylindrical image carrier that rotates once, and the image carrier extends perpendicularly to the plane of the paper. A cleaning device 2 is disposed parallel to a body 1 (referred to as a photoreceptor), and one free edge of a cleaning blade 3 attached to the cleaning device 2 hits the surface of the photoreceptor traveling in the direction of arrow A. The cleaning blade scrapes off residual toner that has reached the cleaning blade position on the surface of the photoreceptor.

The upstream side of the cleaning blade 3 as seen in the direction of travel of the photoconductor is made of an elastic material such as silicone rubber, polyurethane, or nylon, and has a rubber hardness (Asuka 0m weight 300gr).
An elastic cleaning roller 4 of 25 to 50 inches is provided, and is rotated by an appropriate drive source (not shown) in the direction of arrow B (or in the opposite direction) to rub against the photoreceptor and remove toner and paper dust. Remove foreign objects such as

Toner and the like removed from the surface of the photoreceptor by the cleaning blade and cleaning roller are conveyed as the roller rotates, reach the position of the scraper 5, are scraped off by this, reach the toner storage section, and are further removed. It is assumed that the conveyance screw 6 discharges the liquid to the outside of the apparatus.

As is well known, around the photoreceptor, there are provided a negative charger, an image signal applying means, a developing device, a transfer charger, a separation means, and other members necessary for forming a fine rain image. Of course, they are not directly related to the present invention, so they are all omitted.

In the cleaning device as described above, although not particularly shown in the figure, for example, the end of the scraper 5 (the side opposite to the side that contacts the cleaning roller) is attached to the rotating shaft 5a, and the and the drive shaft of the cleaning roller by a known intermittent movement mechanism, or
A well-known and appropriate method can be used, such as turning on and off a switch using a cam or the like to intermittently energize or deenergize a solenoid, thereby separating the scraper that is always biased toward the roller 4 by a spring or the like. Using known means, the scraper 5 is arranged to be separated from the roller 4 at least once during the operation of the cleaning roller.

The toner-attached portion on the surface of the cleaning roller is 1/loo to the entire circumference of the roller, preferably 1150-
115.

With the above configuration, a part of the toner that should originally be removed by the scraper remains on the cleaning roller and reaches the pressure contact part with the photoconductor again, so it can be used even in the case of originals with many white backgrounds as described above. Since a sufficient layer of toner is formed, the desired abrasive action is carried out, and deterioration in image quality can be prevented even when many copies are made.

The above photoreceptor was constructed by sequentially laminating the following adhesive layer, charge generation layer, and charge transport layer on an aluminum cylinder having an outer diameter of 60 m5+.

As an adhesive layer, an ammonia aqueous solution of casein (11.2 gr of casein, 1 gr of 28% ammonia water, 222 g of water)
+al) Apply by dip coating method and dry to a coating amount of 1. A subbing layer of Ogr/m was formed.

For the charge generation layer, 1 part by weight of a charge generation material having the following structure, butyral resin (S-LEC BM2: manufactured by Tanezu Kagaku Co., Ltd.)
1 part by weight and 30 parts by weight of isopropyl alcohol were dispersed for 4 hours using a ball mill disperser.

dip coating this dispersion onto the adhesive layer;
This was dried to form a charge generation layer. The initial thickness of the layer was 0.35 μm.

For the charge transport layer, a charge transport material represented by the following formula was used, and 1 part by weight of the material, 1 part by weight of polysulfone resin (P1700, manufactured by Union Carbide), and 6 parts by weight of monochlorobenzene were mixed. Stir and dissolve.

This solution was applied to the charge generation layer by a dip coating method and dried to form a film. The film thickness at this time was 13 m.

When paper was passed through the photoconductor described above using a leaning device as shown in Figure 1, good images were obtained with no image blurring or image blurring even after 10,000 sheets were passed. Ta.

In addition, the amount of toner consumed is small, and when the above-mentioned method is applied, the amount of toner required to make 10,000 copies is approximately 120.
00 copies were obtained.

FIG. 2 shows another embodiment of the present invention, which basically has the same configuration as that shown in FIG. Parts corresponding to those in are shown with the same reference numerals.

In this device, an appropriate number of rod-shaped magnetic bodies 8 are arranged around the inside of the cleaning roller and extend in the longitudinal direction thereof.

With this configuration, when the scraper is separated from the cleaning roller, the toner tends to be attracted to the cleaning roller, so that the toner does not fall due to vibrations, etc., and a single layer of toner can be reliably formed.

When paper was passed in the same manner as described above using the leaning roller, good quality images were obtained even after passing 10,000 sheets.

For comparison, the cleaning device shown in FIG.
When paper was passed while the scraper was kept in contact with the cleaning roller, deterioration in image quality due to one image deletion was observed after approximately 1,000 sheets were continuously passed.

As explained above, according to the present invention, there is no need to increase the amount of toner consumed, there is no need to particularly accurately control the amount and timing of toner deposition, and the present invention has an extremely simple configuration and is stable. It can perform a cleaning action.

Although the invention has been described above with respect to a copying machine equipped with a rotating cylindrical photoreceptor, the invention is not limited thereto, and may be applied to other types of copying machines, other types of image forming apparatuses, and printers. It is easy to understand that it can also be applied to

(3) Effects of the Invention Since the present invention has the configuration described above, a stable cleaning action can be obtained over a long period of time regardless of the condition of the original, which greatly contributes to obtaining high-quality images. .

[Brief explanation of the drawing]

FIG. 1 is a side view of a main part showing an embodiment in which the present invention is applied to a copying machine equipped with a rotating cylindrical photoreceptor. FIG. 2 is a side view showing another embodiment same as the above. 1... Φ photoreceptor, 2... cleaning device, 3... meeting...
cleaning blade, 4... cleaning roller,
5...Scraper, 8...Magnetic material. Figure 1

Claims (2)

[Claims] (1) A cleaning roller that rubs and removes residual toner and other foreign matter from the image carrier, and a scraper that comes into contact with the cleaning roller and forms a thin layer of toner on the surface of the roller with a portion of the toner transferred thereto. 1. A cleaning device comprising: separating the scraper from the cleaning roller at least once during operation of the cleaning roller. (2) The cleaning device according to claim 1, wherein the cleaning roller is provided with a magnetic material.