JPH0580673B2 - - Google Patents

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 forming a transferable toner image on a moving image carrier, this toner image is transferred to a transfer material, and then residual toner remaining on the surface of the image carrier is removed using a cleaning blade or other appropriate means. Image forming apparatuses in which the cleaning process is repeated are conventionally well known.

In such image forming devices, fine paper particles generated from the transfer material, which is mainly paper, deposits such as precipitated rosin and talc, and nitrogen oxides generated due to the presence of high pressure generating members in the device. Various foreign substances such as discharge products are generated, so
In addition to removing the residual toner as described above, the cleaning device must also remove these foreign substances.

These foreign substances may lower the resistance of the surface of the image carrier and cause image deterioration, and this effect is particularly significant in a high humidity environment.

In order to avoid such drawbacks, the above-mentioned precipitates and
It has already been proposed to remove discharge products and the like.

FIG. 3 is a side view of the main parts schematically illustrating a case where such means is applied to a copying machine, in which a photosensitive member 11 is placed close to a photosensitive member 10 formed in the shape of a rotating cylinder. After the body surface is uniformly charged,
An electrostatic latent image is formed by the light image 12 applied at the exposure section.

This latent image is visualized by the developing device 13, and after this developed image is transferred to the transfer material supplied from the passage 14 by the action of the transfer charger 15, it is transferred to the next process such as the fixing part. reach. At this time, residual toner remaining on the surface of the photoreceptor without contributing to transfer reaches the cleaning device 16, and the cleaning blade 16a
removed by

At this time, in the illustrated copying machine, a sliding roller 16b made of an elastic material is placed upstream of the cleaning blade 16a and is configured to press and rub against the surface of the photoreceptor so as to rotate relative to the surface of the photoreceptor. It is preferable to use silicone rubber, silicone sponge, etc. for the roller 16b, and by doing so, it is possible to rub and remove foreign substances such as the discharge products as described above.

The removed foreign matter is removed by the scraper 16c along with the toner scraped off by the cleaning blade.
The screws are removed and guided by the screw conveyor 16d, and then discharged to the outside of the cleaning device by the screw conveyor 16d.

As explained above, by using the elastic rubbing roller in combination with well-known toner removal means such as cleaning blades and fur brushes, it is possible to effectively remove precipitates other than residual toner, corona discharge products, etc., and produce high-quality images. Obtainable.

As mentioned earlier, using silicone rubber as an elastic rubbing roller is superior in terms of functionality and durability, but the silicone oil contained in this type of material gradually invades the surface. As a result, oil adheres to the photoreceptor, toner sticks to it, and there is a risk that the oil will be transferred to the transfer material and cause fogging on the image. Such development is not so noticeable in a high humidity environment, but is particularly noticeable in a low humidity environment.

Furthermore, if the image forming apparatus has been stopped for a long period of time, a large amount of leached oil may adhere to the roller pressure area of the image carrier, and toner may adhere to this area, causing deterioration of image quality. Something happened.

This invention has been made to deal with the above-mentioned current situation, and the above-mentioned drawbacks can be overcome by moving the elastic rubbing roller toward and away from the image carrier as necessary. The object of the present invention is to provide an image forming apparatus.

(2) Structure of the invention (technical means and effects for solving the problems) In order to achieve the above object, the present invention includes a cleaning blade that comes into contact with the image carrier, and an oil-containing elastic roller, and the image carrier In a cleaning device for removing residue from a body surface, the oil-containing elastic roller is disposed upstream of a cleaning blade when viewed in the running direction of the image carrier so as to be able to approach and separate from the image carrier. When the humidity in the vicinity is higher than a predetermined value, the oil-containing elastic roller contacts the image carrier to clean the surface of the image carrier together with the cleaning blade, and when the humidity is lower than the predetermined value, the oil-containing elastic roller contacts the image carrier and cleans the surface of the image carrier together with the cleaning blade. This device is characterized in that the roller is separated from the image carrier and the cleaning blade cleans the surface of the image carrier.

With this configuration, it is possible to sufficiently remove deposits other than residual toner, such as deposits from the transfer material adhering to the surface of the image carrier and discharge products caused by the presence of a high-pressure member, and It is also possible to eliminate contamination of the image bearing member due to oil exuding from an oil-containing elastic roller such as a silicone roller, and deterioration in image quality caused by this.

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

FIG. 1 is a side view of the main parts showing the case where the present invention is applied to a copying machine having a configuration similar to that of FIG. , an exposure section 3 for forming an electrostatic latent image;
A developing device 4, a transfer material supply path 5, a transfer charger 6, a cleaning device 7, etc. are provided, and the basic image forming process is the same as that shown in FIG. 3, so a description thereof will be given below. Omitted.

The cleaning device 7 in the illustrated embodiment is provided with a cleaning blade 7a, and residual toner that does not contribute to transfer and remains on the surface of the photoreceptor is scraped off by this cleaning blade.

A magnetic roller 7b is disposed within the cleaning device upstream of the blade, and a magnetic brush formed on the roller 7b rubs the surface of the photoreceptor to remove foreign matter such as paper dust. The toner removed from the photoconductor surface is then transferred to the screw conveyor 7c.
shall be discharged from the cleaning device by

In the thus constructed cleaning device, an elastic rubbing roller 7d made of an oil-containing elastic material such as silicone rubber or sponge is further disposed.

As shown in the figure, the elastic sliding roller 7d is pivotally supported by one end of a rod 8, and the other end of the rod 8 protrudes outside the casing of the cleaning device, and is attached to the core of the solenoid 9. There is. A scraper 7e is in contact with the rubbing roller 7d to scrape off foreign matter adhering to the roller.

The solenoid 9 is connected to a humidity detection member 18 via a control unit 17, and in response to the humidity detected by the humidity detection member 18, the solenoid is energized and de-energized to cause the rod 8 to slide. The roller 7d is rubbed against or separated from the surface of the photoreceptor.

The above operation of the rubbing roller is such that when the relative humidity exceeds 45%, the controller activates a solenoid to press the rubbing roller against the photoreceptor, and when the relative humidity drops below that, the roller is separated from the photoreceptor. Further, the roller is configured to be separated from the photoreceptor even when the operation of the copying machine is stopped.

Although the illustrated device is equipped with a humidity detection means, it is of course possible to use means for directly detecting the surface resistance of the photoreceptor instead of humidity detection, and to control the rubbing roller using this. It is.

FIG. 2 shows another embodiment of the present invention, showing a copying machine similar to that of FIG. 1, and similar parts are designated by the same reference numerals.

In this embodiment, the end of the rod 18 that pivotally supports the elastic rubbing roller 7d is exposed at a suitable location outside the copying machine, so that if an image is blurred, the sliding roller 7d can be moved manually to the photoreceptor. The image quality will be restored by removing foreign matter by pressing it against the surface of the lens.

The cleaning blade in the above embodiments is not limited to this, and other cleaning means such as a fur brush can be used.
Further, it is not necessary to use a magnetic roller, and a fur brush, scooping sheet, etc. can also be used. Furthermore, it goes without saying that the means for displacing the rubbing roller is not limited to a solenoid.

(3) Effects of the Invention As explained above, according to the present invention, the cleaning blade and the oil-containing elastic roller that can move toward and away from the image carrier selectively perform cleaning according to the humidity near the image carrier. Since the image bearing member can be cleaned using a cleaning blade or a cleaning blade and an oil-containing elastic roller, residual toner and other foreign matter adhering to the image bearing member can be effectively removed, and the elastic roller This greatly contributes to constantly and stably obtaining high-quality images by avoiding deterioration in image quality due to adhesion of exuded oil due to contact with the image carrier for a long period of time.

[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, FIG. 2 is a side view of a main part of another embodiment of the invention, and FIG. 3 shows a known cleaning means for a copying machine. FIG. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 2... Charger, 4... Developing device, 7... Cleaning device, 7a... Cleaning blade,
7d...Elastic rubbing roller.

Claims (1)

[Scope of Claims] 1. A cleaning device that includes a cleaning blade that comes into contact with an image carrier and an oil-containing elastic roller and removes residue on the surface of the image carrier, wherein the oil-containing elastic roller is attached to the surface of the image carrier. The oil-containing elastic roller is disposed on the upstream side of the cleaning blade when viewed in the running direction so as to be able to move toward and away from the image carrier, and when the humidity near the image carrier is higher than a predetermined value, the oil-containing elastic roller is brought into contact with the image carrier. and cleaning the surface of the image carrier together with the cleaning blade, and when the humidity is lower than a predetermined value, the oil-containing elastic roller is separated from the image carrier and the cleaning blade cleans the surface of the image carrier. A cleaning device characterized by: