JPS608887A - Cleaning device - Google Patents

Abstract

PURPOSE:To eliminated difference in the coefficient of friction of a blade against a photosensitive body and stabilize a cleaning function by supplying a developer to a photosensitive body with a biased magnetic brush and forming a developer layer before a remaining developer is removed with the blade. CONSTITUTION:The residual developer on the photosensitive body 1 which is scraped off with the cleaning blade 27 is recovered by the rotation of a magnetic roller 28, but the magnetic brush 28a of the developer is formed on the roller 28 and rubbed against the photosensitive body 12 and a bias voltage is impressed to the roller 28, so toner sticks to the entire surface. Therefore, axial variation in the coefficient of friction of the photosensitive body is reduced, so the setting condition of the pressure, angle, etc., of the blade 27 is given a margin; even when magnetic toner for pressure fixation is used, excellent cleaning is carried out and the photosensitive body is not damaged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cleaning device for a photoreceptor provided in, for example, an electrophotographic copying machine.

[Technical background of the invention and its problems]

An example of this type of cleaning device is shown in FIG. 1. That is, in the figure, 1 is a main body of the apparatus provided facing the photosensitive drum 2, a cleaning blade 3 is provided on the upper side of the main body 1 of the apparatus, and a recovery auger 4 is provided on the lower side of the main body 1 of the apparatus. There is. 5
is a mylar blade to prevent toner from falling off.

The toner a remaining on the photosensitive drum 2 is scraped off and cleaned by the cleaning plates 1 to 3, and the scraped toner is collected by the collection auger 4.

By the way, the frictional force that acts on the cleaning blade 3 during cleaning is due to the materials of the cleaning blade 3 and the photoreceptor drum 2, and also due to the toner adhering to the S-body drum 2. : 2 sounds.

- To give a list of columns, the r strain friction coefficient for the Se photoconductor when there is no toner is 1, and the J friction coefficient a when toner is present is 0.4. As described above, there is a large difference in the coefficient of friction depending on the presence or absence of toner. Therefore, the way the cleaning blade 3 is turned over is the area where the toner is, for example, copy paper passes through and the toner is transferred to the area and onto the photoreceptor drum 2. There is a difference between the area where there is almost no remaining area and the area where almost no remaining area is left, and especially in the case of pressure fixing magnetic toner, it is extremely difficult to set the area so that both areas are sufficiently cleaned.

For this reason, in the past, when making several copies, there were inconveniences such as toner landing on the photoreceptor drum 2 in the form of black spots, or a single dove on the surface of the photoreceptor drum 2. .

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a cleaning device that eliminates the difference in the coefficient of friction of the cleaning blade against the photoconductor and that enables good cleaning. It is.

[Summary of the invention]

In order to achieve the above object, the present invention supplies a developer to the photoreceptor by a developer supplying means to form a developer layer before residual developer on the photoreceptor is removed by a cleaning blade.

[Embodiments of the invention]

The present invention will be described below with reference to one embodiment not shown in FIGS. 2 and 3. In the figure, reference numeral 11 denotes the main body of the slave copying machine, and a photosensitive drum 12 is provided within this main body.

A charger 13, a developer J4, a transfer charger 15, .
A peeling charger 16 and a cleaning device 17 are provided. Further, a paper feed cassette 18 is provided at the lower part of one side of the main body 11, and a transfer paper 19 is accommodated in this paper feed cassette 18. The transfer paper 19 is passed through the take-out roller 20 and taken out one by one.
The image is transported between the photosensitive drum 12 and the transfer/separation charger 15, 16 by the transport section 2. Further, 22 is a second conveyance section, and this second conveyance section 22 is adapted to convey the transfer paper 19 that has passed through the photosensitive drum 12. Upper 41 second conveyance section 22
A fixing device 23 and a paper ejection roller 24 are provided on this side. 25 is an 11 paper tray.

On the other hand, on the top, 11 is shown as cleaning, and 17 is written as ti phrase j'y as shown enlarged in FIG. That is, in the figure, 26 is a container, and on the front side of this container N526, 6, t clinic blade 2, and a lower part 111111 are provided with a Macnet roller 28 as moss supply means.
There is. In addition, 30 is a collection O, and this collection O is insulated between 30 and the magnet roller 28.
II! ! A doctor 29 is provided. In addition, the magnet roller 28 has a bias voltage of DC600V.
(Can be positive or negative) is applied.

During image formation, the top of the photosensitive drum 12 is charged by the charger 13 and imagewise exposed by an exposure system (not shown) to form a static 'ttL latent image. This electrostatic latent image is visualized by supplying one-component magnetic toner as a developer in the developing device 14 and sent to the transfer charger 15 . On the other hand, at this time, the transfer paper 19 in the paper feed cassette 18 is taken out by the take-out roller 20 and sent between the photosensitive drum 12 and the transfer charger 15 by the first conveying section 21. Photosensitive drum 12
The upper electrostatic latent image is transferred to the transfer paper 19 by the action of the transfer charger 15, and then, by the action of the peeling charger 16, it is peeled off from the top of the photoresistance ram 12 and transferred to the fixing device 23 by the second conveyance section 22. The image is then fixed. The transfer paper 19 on which the image has been fixed is discharged onto the paper discharge tray 25 from the paper discharge roller 24G. on the other hand,
During image transfer, not all of the developer is transferred to the transfer paper 19, but +;I( remains on the photoreceptor drum 12. This remaining developer is sent to the cleaning device 17, where it is removed. The scraped developer is then scraped off by the cleaning blade 27. This scraped off developer is collected by the rotation of the magnet roller 28, and the collected developer is scraped off from the magnet roller 28 by the blade 29. The developer is sent to the auger 30, and as the auger 30 rotates, it is transported to a collection box (not shown) on the front side of the machine.

By the way, during this cleaning, the magnetic roller 2
A developer magnetic brush 28m is formed on the developer drum 8, and is brought into sliding contact with the photoreceptor drum 12, and at the same time, a /NJ ias voltage is applied to the Macnet roller 28. As a result, the toner is completely adhered to the photoreceptor drum 12.
Cleaning blade 2 with this toner attached
scraped off by 7.

As described above, since toner is forcibly attached to the photoreceptor drum 12 before cleaning, changes in the coefficient of friction in the axial direction of the photoreceptor drum 12 can be reduced as much as possible, and the way the cleaning blade 27 is turned over can be minimized. can be equalized.

Therefore, the setting conditions such as the pressure and angle of the cleaning blade 27 can be varied, allowing for good cleaning.

Note that the bias applied to the magnet roller 28 may be an AC voltage. In this case, the highly charged toner has the effect of neutralizing its charge and weakening its adhesion.

〔Effect of the invention〕

As explained above, the present invention removes developer remaining on a photoreceptor with a cleaning blade, and before removing the residual developer with the cleaning blade, the developer is supplied to the photoreceptor to remove the developer. Since the developer supply means for forming a layer is provided, the frictional force of the cleaning blade against the photoreceptor can be made uniform, and the cleaning power can be maximized. therefore,
Even magnetic toner for pressure fixing, which has been difficult to do in the past, can be cleaned well and the photoreceptor is not damaged.

[Brief explanation of the drawing]

Figure 1 is a side sectional view showing a conventional cleaning device;
0 and 3 show one embodiment of the present invention, and FIG.
The figure is a schematic diagram of the electronic copying machine, and FIG. 3 is a side sectional view of the cleaning device. 12... Photoreceptor, 27... Cleaning blade,
28...Developer supply means (magnetic roller).

Claims (5)

[Claims] (1) A developer in which developer remaining on a photoreceptor is removed by a cleaning blade, and the developer is supplied to the photoreceptor to form a developer layer before the residual developer is removed by the cleaning blade. A cleaning device characterized by comprising a supply means. (2) The cleaning device according to claim 1, wherein the developer supply means is a magnetic brush roller. (3) The cleaning device according to claim 2, wherein a bias is applied to the magnetic brush roller. (4) The cleaning device according to claim 3, wherein the bias is an AC voltage. (5) The cleaning device according to claim 1, wherein the developer is a one-component magnetic toner.