JPS6024944B2 - Electrophotographic cleaning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a cleaning device for removing residual toner on a photoreceptor in electrophotography.

Conventionally, various electrophotographic cleaning devices have been proposed. For example, cleaning devices using fur brushes or webs are widely used because the setting position can be selected arbitrarily. However, in cleaning with these cleaning devices using fur brushes or webs, a large amount of floating toner is generated, so a dust collecting fan or the like is indispensable. On the other hand, there is also a cleaning device that uses a blade, and although this device is simple,
There are problems such as the inability to arbitrarily select the setting position, damage to the surface of the photoreceptor, and the need for a toner scatter prevention device. Further, in any of the above-mentioned cleaning devices, since the toner removed by cleaning is reused, a means for transporting the toner to the developing device is required. The present invention has been made for the purpose of eliminating the drawbacks of the conventional ones described above and providing an electrophotographic cleaning device that can reliably remove toner on a photoreceptor with a simple configuration. In addition to the developing magnet, a cleaning magnet with a higher magnetic flux density than the developing magnet is installed, and the developing magnet is used during development, and the cleaning magnet is used during cleaning to maintain a constant angle between the photoreceptor and the magnetic pole. It is designed so that it is placed in a position facing each other.

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 1 shows the overall outline of the electrophotographic device.
A charging section 3, an exposing section 4, a developing section 5, a transferring section 6, and a static eliminating section 7 are located around the photoreceptor 1 rotating around a central axis 2 at appropriate intervals.

Among these, a non-magnetic sleeve 8 that rotates around a central axis 9 is disposed in the developing section 5, and a plurality of magnets 10 for attracting the magnetic toner T to the surface of the sleeve 8 are disposed within the sleeve 8. , 10... are fixedly arranged. Also, above this sleeve 8 is a hopper 1.
1 is disposed, and a magnetic toner T is provided on the surface of the sleeve 8.
It is now possible to combine the two. Thus, an image of the document is formed in the exposure section 4 on the photoconductor 1, which has been given a potential in the charging section 3, and an electrostatic latent image is formed.

Magnetic toner T is supplied from the sleeve 8 to this electrostatic latent image in the developing section 5, and the toner T is attracted by electrostatic attraction force. Next, the toner T on the photoreceptor 1 is transferred to a transfer paper 9 in a transfer section 6, and then the charge remaining on the photoreceptor 1 is removed in a removal section 7. Thereafter, when the photoreceptor 1 rotates once again, the untransferred toner T remaining on the photoreceptor 1 is cleaned by the developing device 5. The developing device 5 is used for both development and cleaning. In this way, one copy is obtained by rotating the photoreceptor 1 approximately twice. The present invention relates to an improvement in cleaning performance in such an electrophotographic copying apparatus. Next, an embodiment of the electrophotographic cleaning apparatus according to the present invention is shown in FIGS. 2A and 2B.

That is, four magnets 10A, 10B, 10C, and 10D are disposed inside the nonmagnetic sleeve 8 adjacent to the photoreceptor 1 with minute gaps between them and the inner circumferential surface 12 of the sleeve 8. However, these magnets 10A, 10B, 1
0C and 10D can be rotated independently with respect to the sleeve 8. In addition, these magnets 10A, 10
Among B, 10C, and 10D, the magnet 10A is used as a developing magnet, the magnet 10B is used as a cleaning magnet, and the remaining magnets 10C and 10D are attracted to the outer peripheral surface 13 of the sleeve 8 when the sleeve 8 rotates. This magnet is used to prevent the magnetic toner T from falling off and for conveyance. Regarding the developing magnet 10A and the cleaning magnet 10B, the developing magnet 10A is connected to the photoreceptor 1 during development, and the cleaning magnet 10B is connected to the photoreceptor 1 during cleaning.
The central axis 9 of the sleeve 8 and the central axis (
(not shown), the center axis 9 of the sleeve 8, the center of the magnets 10A, 10B at the stop position, and the twill line make the same angle at the time of development and cleaning. The magnet densities are varied at an angle of about 20° to 30° to obtain the magnet densities for developing and cleaning conditions.

Further, the developing magnet 10A moves the magnetic toner T from the outer peripheral surface 13 of the sleeve 8 to the photoreceptor 1, while the cleaning magnet 10B moves the magnetic toner T from the photoreceptor 1 to the outer peripheral surface 13 of the sleeve 8. Therefore, the magnetic flux density of the cleaning magnet 10B is set higher than the magnetic flux density of the developing magnet 10A.For example, the developing magnet 10A is 1400 Gauss, and the cleaning magnet 1
08 is said to be 1600 Gauss. According to the above-described configuration, good development and cleaning can be achieved by simply rotating the magnets 10A and 10B used during development and cleaning, respectively, so as to face the photoreceptor 1.

Next, FIG. 3 shows an embodiment for improving the cleaning performance of the non-transfer area of the photoreceptor, in which the sleeve 8 is divided into a sleeve 8A for the transfer area and sleeves 8B and 8C for the non-transfer area. A developing magnet and a cleaning magnet (not shown) are disposed inside the sleeves 8B and 8C for the non-transfer section, and only these sleeves 8B and 8C for the non-transfer section are rotated during development and cleaning, and the corresponding magnets are rotated during development and cleaning. and a photoreceptor (not shown). In addition, Fig. 2 A,
In the embodiment shown in FIG. The magnets and the cleaning magnets may be arranged alternately, and the magnets may be rotated in the same direction to take positions facing the photoreceptor.

As described above, in the electrophotographic cleaning device according to the present invention, in addition to the developing magnet, a cleaning magnet having a higher magnetic flux density than the developing magnet is provided in the sleeve of the developing section of the electrophotographic device, and during development, During cleaning, the cleaning magnet takes a position facing the photoconductor with a constant magnetic pole angle, so the magnetic toner on the photoconductor can be reliably returned to the developing section with a simple configuration. Therefore, the entire device can be miniaturized and can be manufactured at low cost, which is an excellent effect.

Another advantage is that the toner collected during cleaning can be reused for development. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an overall outline of an electrophotographic apparatus, FIGS. 2A and 2B are explanatory diagrams showing an embodiment of an electrophotographic cleaning apparatus according to the present invention, and FIG. 2B shows the state during development, FIG. 2B shows the state during cleaning, and FIG. 3 is an explanatory view of the main parts of another embodiment of the electrophotographic cleaning apparatus according to the present invention.

DESCRIPTION OF SYMBOLS 1... Photoreceptor, 5... Developing part, 8... Rotating sleeve, 10... Magnet, T... Toner.

Multi-J diagram Multi-Z diagram Many 3 figures

Claims (1)

[Claims] 1 A developing magnet and a cleaning magnet having a higher magnetic flux density than the developing magnet are arranged in a rotating sleeve that is adjacent to the photoconductor and supplies magnetic toner to the photoconductor. An electrophotographic cleaning apparatus characterized in that, during cleaning, both of the cleaning magnets can be rotated so that the angles between the photoreceptor and the magnetic poles are kept constant and the cleaning magnets face each other.