JPH0391789A - Photosensitive body cleaning method for image forming device - Google Patents

Abstract

PURPOSE:To perform an excellent cleaning action on a photosensitive body by reversely rotating the photosensitive body after the photosensitive body is cleaned and then releasing a cleaning blade and a fur brush from the photosen sitive body in that order. CONSTITUTION:After a normal cleaning action, the cleaning blade 81 and the fur brush 82 are released from the photosensitive drum 1. For the releasing, at first, the photosensitive body drum 1 is reversely rotated in the direction of an arrow B. Thus, toner powder heaped up on the cleaning blade 81 is attracted to the fur brush 82 and removed. After or simultaneously with the photosensitive drum 1 is reversely rotated, the cleaning blade 82 is released from the photosensitive drum 1, and then, the fur brush 82 is released from the photosensitive drum 1. Finally, the rotation of the fur brush 82 is stopped, the operation is shifted to the following image forming stage and image formation is started.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to cleaning toner powder remaining on the surface of a photoreceptor by a cleaning blade and a Ferg brush that are arranged so as to be able to come into contact with and release from the photoreceptor. The present invention relates to a photoreceptor cleaning method for an image forming apparatus that removes .

[Prior Art] Recently, in various color image forming devices such as copying machines, printers, and facsimile machines, devices have been developed that transfer multi-color images formed overlappingly on a photoreceptor onto a transfer medium in a single transfer process. has been done. In such an apparatus, the steps of charging, exposing, and developing are repeatedly performed on the surface of the photoreceptor for each color, thereby forming visible toner images of each color in superimposition on the photoreceptor. The multiple color images formed on this photoreceptor are transferred onto a transfer medium at once by a transfer charger.

After transfer, the photoreceptor is subjected to a cleaning process for more than one rotation using a cleaning blade and a Ferg brush provided in the cleaning mechanism, thereby removing toner powder remaining on the surface of the photoreceptor and cleaning the photoreceptor. Initialization is now performed. On the other hand, in order to prevent the color image formed on the photoreceptor from being removed by the cleaning mechanism during the image forming process in such an apparatus, the cleaning mechanism is moved to a predetermined position and retracted from the photoreceptor, The cleaning blade and Ferg brush provided in the cleaning mechanism are released and separated from the surface of the photoreceptor.

[Problems to be Solved by the Invention] However, especially in the one-time transfer type image forming apparatus as described above, the cleaning process of the photoreceptor is very important.

That is, if uncleaned toner powder remains on the photoreceptor, the remaining toner is easily taken into the developing device of another color, which often results in color mixing. SUMMARY OF THE INVENTION Therefore, the present invention provides a method for cleaning a photoreceptor of an image forming apparatus, which performs a good cleaning action on the photoreceptor and prevents the occurrence of color mixture, especially in a multicolor image forming process. The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for removing toner remaining on the photoreceptor after transferring the toner visible image formed on the photoreceptor to the transfer medium side. In a method for cleaning a photoreceptor of an image forming apparatus, the powder is removed by a cleaning blade and a Ferg brush that are disposed so as to be able to come into contact with and release from the surface of the photoreceptor. To release from the photoconductor at the end of photoconductor cleaning,
First, reverse the photoreceptor so that the toner powder accumulated on the cleaning blade is moved to the fur brush side.
Next, the toner powder gathered on the fur brush side is adsorbed to the fur brush and removed from the photoreceptor, and after the cleaning blade is released from the photoreceptor, the fur brush is released from the photoreceptor. I have it. [Function] In the means having such a configuration, the toner powder accumulated on the cleaning blade is moved to the fur brush side by the reversing operation of the photoreceptor performed after cleaning the photoreceptor, and the toner powder is removed. It is adsorbed and removed by the fur brush, and then the cleaning mechanism is completely released from the photoreceptor. As a result, the toner powder on the photosensitive drum 1 is almost completely removed.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

First, an example of an image forming apparatus used in carrying out the present invention will be described. As shown in FIG. Around the photoreceptor drum 1, along the rotation direction, there are a corona charging charger 2 that uniformly charges the surface of the photoreceptor drum 1, and an exposure optical system that writes image information on the photoreceptor drum 1 to form an electrostatic latent image. Optical path 3, color developing devices 4A, 4B, 4 for each color that supply toner to the electrostatic latent image formed on the photoreceptor drum 1 and develop it to obtain a toner visible image.
G, 4D. A transfer charger 5 that transfers a color toner visible image obtained by development onto a transfer paper, a transfer belt 7 that feeds and discharges the transfer paper 6 to the transfer section where the transfer charger 5 is arranged, and a surface on the photoreceptor drum after transfer. Various devices are attached, such as a cleaning device 8 for scraping off toner remaining on the surface of the photoreceptor drum and a quenching lamp 9 for erasing unnecessary charges remaining on the surface of the photoreceptor drum after transfer.

The color developing devices 4A, 4B, 4C, and 4D have respective developing casings 41a, 4lb, 41c, and 41d.
Developing sleeves 42a, 42b, 42c, and 42d each consisting of a cylindrical member and serving as a developer carrier are provided therein. These developing sleeves 42a, 42b, 42
c, 42d are each developing casing 41a, 4lb,
41c, 4]. It is exposed toward the photoreceptor drum 1 side from an opening provided at d, and is arranged to face the surface of the photoreceptor drum 1 so as to have a constant development gap. And these developing sleeves 42
A toner transfer area, that is, a development area is formed in each opposing portion of the photoreceptor drum 1 and a, 42b, 42c, 42d.

Each of such developing sleeves 4.2a, 42b, 42c,
A two-component developer consisting of toner particles and carrier particles is adsorbed in the form of spikes on the surface of the magnetic brush 42d, thereby forming magnetic brushes. The tip portions of each of these magnetic brushes are elastically contacted in the development area, that is, the development position, and the toner transfer action, that is, the development action is performed at the contact portion.

On the other hand, the transfer paper 6 as a transfer medium fed from a paper feed cassette (not shown) provided as a storage section of the automatic paper feed section is fed into the transfer section at a predetermined timing, and is transferred to the photosensitive drum 1 by the transfer charger 5. The upper visible images 1 to 4 are to be transferred onto the transfer paper 6. Further, the transfer paper 6 on which the visible toner image has been transferred is sent to a fixing unit (not shown), where the visible toner image is fixed and then ejected to a paper ejection tray. ing.

Furthermore, the cleaning device 8 is provided with a cleaning blade 81 and a fur brush 82 that are placed in contact with the surface of the photoreceptor drum 1 . These cleaning blade 81 and Ferg brush 82 are brought into contact with and released from the photoreceptor drum 1! i2iff
The cleaning blade 8l is arranged downstream of the fur brush 82 in the conveying direction of the photosensitive drum 1 (direction A in the figure). Above fur brush 8
2 is made of a conductive fiber member, and a bias voltage having a polarity opposite to that of the toner is applied to the fur brush 82 via a conductive roller 83 placed in contact with the fur brush 82. The toner powder on the photoreceptor drum Y is attracted by the fur brush 82 and removed by the electrostatic adsorption force.

Further, the toner attached to the fur brush 82 is attracted to the conductive roller 83, and the toner is also absorbed by the scraper.
It is scraped off into the cleaning device 8 by the sliding force of 84. Also, this scraped off toner is
By the conveying action of the l-ner discharge coil 85, it is appropriately discharged outside the apparatus. On the other hand, toner powder that has passed through without being captured by the fur brush 82 and toner powder that has re-adhered to the photoreceptor drum 1 from the fur brush 82 is removed from the photoreceptor drum 1 by the Jffm force of the cleaning blade 81. It is scraped off and eventually removed.

Furthermore, a corona charger 86 is provided upstream of the fur brush 82 in the conveying direction of the photosensitive drum 1 (direction A in the figure).
By the discharge action from 6, the photosensitive drum 1 and the toner are neutralized before cleaning by the cleaning blade 81 and the fur brush 82, and the polarity of the toner is controlled.

The entire cleaning device 8 is configured to be rotatable about the installation position of the corona charger 86 as a fulcrum, and when it is rotated in the direction shown by the arrow in FIG. After that, the fur brush 82 is released from the photosensitive drum 1. When such a release operation of the cleaning device 8 is performed,
The photosensitive drum 1 is rotated in the reverse direction shown by the arrow -1'-DB.

When image formation is performed in this apparatus, the steps of charging, exposing, and developing are repeatedly performed on the surface of the photoreceptor drum for each color, so that a visible toner image of each color is exposed to light. The body drum 1 is formed in a superimposed manner. The formed multi-color image is transferred onto the transfer paper 6 at one time by the transfer charger 5.

In such an image forming process, the cleaning blade 81 and fur brush 82 of the cleaning device 8 are released from the surface of the photoconductor drum 1 so that the color image formed on the photoconductor drum l is not removed by the cleaning device 8. - Has been evacuated to a separate location.

Next, the cleaning operation of the photoreceptor drum ↓ performed after image formation is performed by the method of the following embodiment.

First, the cleaning blade 81 and fur brush 82 of the cleaning device 8 are rotated from the retracted position to the operating position where they are in contact with the surface of the photosensitive drum 1. First, the toner on the photosensitive drum 1 is attracted by the fur brush 82 and removed by the bias voltage applied to the fur brush 82. At this time, the 1-ner powder that passed through the fur brush 82 without being removed and the fur brush 8
The 1-ner powder re-adhered to the photoreceptor drum 1 side from 2 is
It is scraped off from the photoreceptor tram 1 by the sliding force of the cleaning blade 81 and is finally removed.

Next, after such a normal cleaning operation, the cleaning blade 81 and the fur brush 82 are released from the photoreceptor drum 1, but at this time, the photoreceptor drum As1 is first reversed in the direction of arrow B. As a result, the toner powder accumulated on the cleaning blade 81 is moved to the fur brush 82 side, and the fur brush 82 is moved to the fur brush 82 side.
The toner powder gathered on the second side is attracted to the fur brush 82 and removed.

After or at the same time as the photoreceptor drum starts to rotate in reverse, the cleaning blade 82 is released from the photoreceptor drum 1 as shown in FIG. 2, and then the fur brush 82 is released from the photoreceptor drum. Finally, the rotation of the fur brush 82 is stopped, and the next image forming step begins.

As described above, in the method of this embodiment, the toner powder deposited on the cleaning blade 81 is moved to the fur brush 82 side by the reverse rotation of the photoreceptor drum 1 performed after cleaning the photoreceptor drum 1, and the toner powder is transferred to the fur brush 82 side. The powder is adsorbed and removed by the fur brush 82. Therefore, according to this method, the toner powder on the photoreceptor drum 1 is almost completely removed. It is desirable that the reversal speed of the photosensitive drum 1 at this time is as low as possible.

If the bias voltage applied to the fur brush 82 is increased when the cleaning device 8 is released as described above, the toner adsorption force of the fur brush 82 can be increased at a necessary timing to improve the toner removal ability. This makes it possible to perform even better toner removal action. Further, by continuing to apply bias to the fur brush 82 even when the cleaning device 8 is released, it is possible to prevent the toner attached to the fur brush 82 from falling.

The present invention can be applied not only to multicolor image forming apparatuses but also to monochrome image forming apparatuses.

When forming a multicolor image, it is necessary to bring the cleaning device 8 into contact with and releasing the photoreceptor drum ↓ every time, but when forming a monochrome image, the cleaning device 8 can be brought into contact with and released from the photoreceptor drum 1 without releasing the cleaning device 8. It can be kept in contact with the side. Further, in the above embodiments, a drum-shaped photoreceptor is used, but it goes without saying that a belt-shaped photoreceptor can also be used.

[Effects of the Invention] As described above, in the present invention, when cleaning a photoreceptor using a cleaning blade and a fur brush in combination, the toner powder deposited on the cleaning blade is removed by the fur brush. After cleaning the photoreceptor, the photoreceptor is reversed, and then the cleaning blade and fur brush are released from the photoreceptor in that order, so that a good cleaning action can be performed on the photoreceptor, especially when cleaning the photoreceptor. In multicolor image formation, it is possible to prevent the occurrence of mixed color images due to toner contamination.

[Brief explanation of drawings]

FIG. 1 is an explanatory side view showing an example of an image forming apparatus for carrying out the image forming method of the present invention, and FIG. 2 is an explanatory side view showing an enlarged view of the cleaning device shown in FIG. It is a diagram. Engineering: Photosensitive drum, 8: Cleaning device, 8: Cleaning blade, 82: Fur brush. (Other l names) b ii ■ place 2 ■ 〒

Claims (1)

[Claims] After the toner visible image formed on the photoreceptor is transferred to the transfer medium, the toner powder remaining on the photoreceptor is removed.
In a method for cleaning a photoreceptor of an image forming apparatus, the cleaning blade and the Ferg brush are arranged so as to be able to come into contact with and release from the surface of the photoreceptor. To release the toner powder from the photoreceptor at the end of cleaning, first rotate the photoreceptor in reverse so that the toner powder accumulated on the cleaning blade is moved to the fur brush side, and then remove the toner powder gathered on the fur brush side. A method for cleaning a photoconductor of an image forming apparatus, characterized in that the fur brush is removed from the photoconductor by adsorbing it to a brush, the cleaning blade is released from the photoconductor, and then the fur brush is released from the photoconductor.