JPS6149665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoconductor cleaning method for removing magnetic toner remaining on the photoconductor surface after transfer using a magnetic brush.

As is well known, there is a method of developing an electrostatic latent image formed on the surface of a photoreceptor using a one-component magnetic toner. This magnetically attracts magnetic toner to the surface of a magnetic roller to form a magnetic brush, and brings the magnetic brush into contact with the electrostatic latent image. At this time, charges of opposite polarity are induced in the magnetic toner by the charges forming the electrostatic latent image, and as a result, the magnetic toner is attracted to the electrostatic latent image and development is performed.

After the magnetic toner image obtained by development is transferred to a copy sheet, such as plain paper, the magnetic toner remaining on the photoreceptor surface must be removed before entering the next copying cycle. As a method of cleaning such a photoreceptor, a method using a magnetic brush as described above is known. After the surface of the photoreceptor after transfer is exposed to corona discharge or light irradiation to erase the charge of the electrostatic latent image, the residual toner is rubbed by a magnetic brush and removed.

However, since the magnetic brush has a relatively weak sliding force, it cannot perform sufficient cleaning. Therefore, the magnetic brush has been strongly pressed against the surface of the photoreceptor to increase the rubbing force, or the magnetic brush has been rotated slowly to perform the removal quietly. Pressing the magnetic brush too hard against the photoreceptor surface causes wear on the photoreceptor surface, and rotating the magnetic brush slowly slows down the overall copying speed.

The cleaning method according to the present invention is characterized by removing residual toner with a magnetic brush while disturbing the adhesion of the residual toner to the surface of the photoreceptor. The magnetic pole parts of the plurality of magnets with the same polarity, which are arranged close to the back surface of the front photoconductor including the magnetic brush, form an irregular magnetic field with a high magnetic field gradient above between the adjacent magnetic poles. The toner on the surface of the photoreceptor as it passes is disturbed, making it easier to clean with a magnetic brush.

In the cleaning method according to the present invention, there is no need to strongly press the magnetic brush against the surface of the photoreceptor, and the magnetic brush can be rotated quickly.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved photoconductor cleaning method for removing residual magnetic toner on the surface of a photoconductor using a magnetic brush.

A further object of the present invention is to provide the above-mentioned cleaning method that can easily and reliably remove residual magnetic toner.

A further object of the present invention is to provide the above-mentioned cleaning method, which removes residual magnetic toner while disturbing its adhesion to the photoreceptor surface.

The above and other objects will become more apparent from the attached drawings and the following description.

In FIG. 1, a magnetic brush 1 is formed on the surface of a non-magnetic sleeve 2 rotating in the direction of the arrow by the magnetic attraction of a magnet roll 3 stationary therein. The material of the magnetic brush 1 is iron powder or the same magnetic toner as the developer. The non-magnetic sleeve 2 can be kept stationary and the magnet roll 3 can be rotated. When rotating the non-magnetic sleeve 2 or the magnet roll 3, the rotating direction may be any direction.

The photoreceptor 4 has a photoconductive layer 5 on its surface made of selenium, zinc oxide, cadmium sulfide, polyvinyl carbazole, etc.
is formed, and the back side is a conductive non-magnetic support 6 made of aluminum or the like. The photoreceptor 4 is formed into a belt shape or a drum shape. The photoreceptor 4 moves in the direction of the arrow, and the magnetic brush 1 comes into contact with its surface.

At a position facing the magnet 1 with the photoreceptor 4 in between, a plurality of magnets 7 are arranged with the same magnetic poles close to the back surface of the photoreceptor. The north pole or the south pole may be directed toward the back surface of the photoreceptor. Alternatively, the entire magnet 7 may be biased toward the photoreceptor entrance side.

A magnet normally forms the strongest magnetic field at its magnetic pole, as shown in Figure 2, but the magnetic field at its third pole is the strongest.
As shown in the figure, when magnets are placed adjacent to each other with the same polarity facing the same direction, there will be a portion with a high magnetic field gradient like A between the magnetic poles. When a photoreceptor holding residual toner passes through such a magnetic field, particles of the residual toner are lifted at the portion A, and the adhesion of toner to the photoreceptor is disturbed. When this process is repeated as shown in FIG. 1, the adhesion of the toner to the photoreceptor becomes weaker and the toner is easily removed by the magnetic brush 1.

Furthermore, if the same magnetic poles of the magnet roller 3 are located at the positions corresponding to the magnetic poles of the magnet 7, the ears of the magnetic brush will lie flat in this area, which will weaken the sliding force of the magnetic brush. , it is possible to reduce wear on the surface of the photoreceptor.

The photoreceptor cleaning method according to the present invention is applied to electrophotographic devices, electrostatic recording devices, and the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIGS. 2 and 3 are explanatory diagrams for explaining the principle of the invention. 1... Magnetic brush, 2... Non-magnetic sleeve, 3... Magnet roll, 4... Photoreceptor,
7...Magnet.

Claims (1)

[Claims] 1 A photoconductor cleaning method in which magnetic toner remaining on the photoconductor surface is removed after transfer using a magnetic brush, in which a plurality of magnetic A photoreceptor cleaning method comprising the step of arranging magnetic pole parts of the same polarity in a row along the photoreceptor traveling direction, and using a magnetic field formed thereby to disturb the adhesion of the residual toner to the photoreceptor surface.