JPS6349770A - Electrode sleeve device for toner image formation - Google Patents

Abstract

PURPOSE:To fix a magnetic piece and an electrode sheet accurately on a sleeve by providing a cylindrical sleeve with a step consisting of a thick and a thin part and fixing the magnetic piece on the thick part at the step. CONSTITUTION:The cylindrical sleeve 3 is not uniform in thickness, but provided with the step consisting of the thick part and thin part. Then the magnetic piece 6 is fixed on the thin part of the step to the overall width of the sleeve and the electrode sheet 5 where electrodes are formed corresponding to picture elements is fixed covering the magnetic piece 6 and thick part. Therefore, no special jig is used to set the magnetic piece 6 and the front end part of the electrode sheet 5 in parallel to a main shaft. Further, the distance between the electrode tip part and magnet surface is reducible, so the magnetic force of the magnets is utilized effectively to accurately fix the magnetic pole piece 6 and electrode sheet 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention is directed to a non-magnetic sleeve that is conveyed between a group of electrodes arranged on a sleeve and a recording body adjacent thereto by a magnet rotating within the sleeve. Electrode sleeve device for toner image formation used in an image forming device of the type that forms an image by applying electrostatic force to the conductive magnetic toner passing through the #electrode group on the recording medium according to the voltage applied to the electrode group. Regarding awns.

(9: Bright background) This type of image forming apparatus is disclosed in Japanese Patent Application Laid-open No. 127578/1983. This device will be explained with reference to FIG. FIG. 4 is an explanatory cross-sectional view showing the main parts of the recording section. The recording sheet (recording body) 4 consists of a surface layer 4a which has been subjected to insulation treatment and a conductive sheet body 4b, and the sheet body 4b is always grounded. The recording sheet 4 is wrapped around a lower roller 12 and a ball roller (not shown) in an endless manner, and is moved in the direction of arrow A by the clockwise rotation of the lower roller 12. is made of a non-magnetic material, and is fixed to a wooden frame on the main body of the device, and a multi-pole magnet 8b is rotatably supported inside it. There is a magnetic piece (ferromagnetic material) on the sleeve 8a near the M short distance with the lower roller 12.
8d is attached, and the upper part of the magnetic piece 8d and the sleeve 8a
Meanwhile, the electrode sheet 8c is obliquely attached in an arc shape. The number of electrodes corresponding to the pixel density is formed on the electrode sheet h8c. Conductive and magnetic toner 20 is supplied onto the surface of the sleeve 88, and spikes of the toner 20 are formed on the surface of the sleeve 8a by the multipolar magnet 8b. When the multipolar magnet 8b rotates in the direction of arrow C, the ears of toner 20 move in the direction of arrow B, which is the opposite direction. The plate lla regulates the height of the toner spikes on the sleeve 8a. The ears of toner 20 whose height has been regulated further move in the direction of arrow B, and the electrode sheet 8
magnetic pieces 8d-h through the electrode sheet 8C.
The spikes of toner 20 come. At this time, the control circuit 22 applies a predetermined voltage to the selected electrode of the electrode sheet 8C according to the image, and the spiked toner 20 on the corresponding compensation electrode is charged to ■, and on the other hand, the toner on the recording sheet 4 is charged. The back side of the insulating surface P+4a is exposed to e, and the toner 20 is therefore placed on the surface layer 4a by electrostatic attraction, overcoming the magnetic attraction of the magnet 8b. Return ni'yo eta record sheet 4
The recording sheet 4 is rotated in the direction of the arrow by the rotation of the lower roller 2, and when it reaches the sleeve 9a made of non-magnetic material, the toner 20 on the surface layer 4a of the recording sheet 4 is removed from the sleeve 9a. The toner is scraped off by the toner spikes 21 on the sleeve 9a due to the magnetic force of the rotating multi-pole magnet 9b inside. The sleeve 9a and the surface layer 4a are separated by a predetermined distance, and a toner regulating blade llb is provided at a predetermined distance from the sleeve 9a. Both ends of the multi-polar magnet 9b are fixed to the main body of the device, both ends of a vibrator-shaped sleeve 9a are rotatably supported by the main body of the device, and the sleeve 9a is connected to a magnet (not shown). cat causes it to rotate in the direction of the arrow. In this way, the image recorded by the toner 20 on the recording sheet 4 by the sleeve 8a is erased by the sleeve 9a.

However, conventionally, it has been a difficult task to align and fix the elongated magnetic piece 8d and the thin electrode sheet 8c to the cylindrical sleeve 8a in such a way that their tips are accurately aligned.

Also, since the magnetic force of the multipolar magnet 8M) is limited, the sleeve 8a should be as thin as possible, and the distance from the electrode sheet 8C on the magnetic piece 8d to the surface of the multipolar magnet 8b should be as small as possible. However, in the conventional method of fixing the magnetic piece 8d on the surface of a single cylindrical sleeve 8a and fixing the electrode sheet 8C thereon, the electrode sheet 8c on the magnetic piece 8d and the multipolar magnet The distance from the surface of 8b was large. Therefore, in order to display an image with an appropriate degree of e on the recording sheet 4, it is necessary to limit the distance between the recording sheet 4 and the electrode sheet 8C to an extremely small value, or to apply a considerably large voltage to the control circuit 22. Ta. However, if the distance between the recording sheet 4 and the electrode sheet 8c is made small, toner fogging occurs and the image on the recording sheet 4 becomes darker than necessary. In this case, it is necessary to increase the withstand voltage of the circuit elements used, which has the disadvantage of increasing costs.

Also, instead of using a plastic magnet mainly made of ordinary ferrite magnets for the multipolar magnet 2, is it possible to strengthen the magnetic force by using a plastic magnet made mainly of rare earth magnets with high holding power? is undesirable due to high cost.

(Object of the Invention) The present invention has been made in order to eliminate the above-mentioned conventional drawbacks in the above-mentioned type of image forming apparatus. It is an object of the present invention to effectively utilize the magnetic force of the magnet and to accurately fix the attachment of a magnetic piece and an electrode sheet.

(Summary of the invention) Kimitsuda consists of a cylindrical sleeve made of a non-magnetic material that surrounds a rotating multipolar magnet, a magnetic piece fixed on the surface of the sleeve, and a group of electrodes arranged on the magnetic piece. , the magnetic toner is transported along the surface of the sleeve by the rotation of the L magnet, and passes between the electrode group and the recording medium adjacent thereto. an electrode sleeve device for forming a toner image by electrostatic force in accordance with a voltage applied between the cylindrical sleeve and the cylindrical sleeve, the cylindrical sleeve having a thick wall portion and a thin wall portion that are stepped; The piece is at the level of the step ff1l:
The thin wall portion is fixed on the thin wall portion.

(Embodiments of the Invention) Hereinafter, the present invention will be explained in detail with reference to FIGS. 1 to 3. The a-forming operation of the six image forming apparatuses will be explained using the various elements 8a, 8b, and 8c in FIG. 4 described above.

The structure is the same as that in FIG. 4 except that the structure described below is used for the portion 8d, so a redundant explanation will be omitted.

In FIGS. 1 and 2, both ends of the main shaft 1 are provided with bearings 9a,
9b, and a gear 10 driven by a gear (not shown) is fixed to the right end of one shaft l. The flanges 10a, 10b support the bearings 9a, 9b, and at the same time fix a substantially pipe-shaped sleeve 3 (corresponding to the aforementioned sleeve 8a) made of a non-magnetic material. The sleeve 3 is made of a non-magnetic material such as plastic resin. Flange 10a.

10b is fixed to the main body of the image forming device (not shown). A multipolar magnet 2 (corresponding to the multipolar magnet 8b described in JIJ) is fixed on the main shaft 1 and is magnetized in the circumferential direction. The sleeve 3 is not a pipe with a uniform thickness, but is a tube having a thick wall portion and a thin wall portion, and has at least one step.A magnetic piece is placed on the thin wall portion of the first step. 6 (corresponding to the above-mentioned magnetic piece 8d) is fixed (this magnetic piece 6 extends over the entire width of the sleeve 3), and the electrode sheet 5 is spread over the magnetic piece 6 and the thick part.
(corresponding to the aforementioned electrode sheet 8c) is fixed. When the main shaft l rotates clockwise in FIG. 1, the ears of conductive magnetic toner on the sleeve 3 are sent counterclockwise along the thick part of the sleeve 3 as in FIG. The toner is placed on the recording sheet 4 on the top of the magnetic piece 6 in the form of an image. The remaining toner that did not get on the recording sheet moves to the thin wall portion of the sleeve 3 and is sent counterclockwise along the sleeve 3. The reason why the sleeve 3 is provided with at least one step is to make the image recorded on the recording sheet brighter.

11'W, the sleeve 3 shown in FIG. 2 is made of plastic resin and is made by extrusion molding, or
As shown in FIG.
1 and a thick sleeve piece 3-2.

In the embodiment of the present invention, since the structure is as described above, the magnetic piece 6
The distance between the tip of the upper electrode sheet 5 and the multipolar magnet 2 can be reduced, and the strength of the magnetic field at the closest position between the recording sheet 4 and the electrode sheet 5 can be increased. Further, the magnetic piece 6 and the electrode sheet 5 are attached to the sleeve 3 on the main shaft 1 based on the step between the thick part and the thin part of the sleeve 3.
Since it can be fixed parallel to the main body, the fixing work becomes easier.

(Effects of the Invention) As explained above, according to the present invention, the magnetic piece and the electrode sheet can be fixed to the sleeve based on the stepped portion on the sleeve surface. The tip of the piece and the electrode can be fixed to the main shaft in a straight line. In addition, since it is possible to reduce the distance between the tip of the electrode and the magnet surface, it is possible to use a strong magnet as in the past, increase the voltage applied to the electrode, or minimize the distance between the recording medium and the electrode. The advantage is that you don't have to worry about doing it.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of an electrode sorbing device for toner image formation according to the present invention, FIG. 2 is a vertical cross-sectional view thereof, and FIG.
The figure is a cross-sectional view of another embodiment, and FIG. 4 is a conventional image forming method.
It is a sectional view of the main part of A position. ■...Main shaft 2...Multipole 7 gnect 3.
...Sleeve 4...Recording sheet 5...Electrode sheet 6...Magnetic piece 8a...Sleeve
8b... Multipolar magnet 8C... Electrode sheet 8
d...Magnetic piece 9a...Erasing sleeve 9b...Rotating magnet 10a, 10b=Flange 12...Lower roller 13a, 13b=-Bearing Fig. 2

Claims (1)

[Claims] It consists of a cylindrical sleeve made of a non-magnetic material that surrounds a rotating multipolar magnet, a magnetic piece fixed on the surface of the sleeve, and a group of electrodes arranged on the magnetic piece. The conductive magnetic toner, which is conveyed along the surface and passes between the electrode group and the recording medium adjacent thereto, is applied to the recording medium according to the voltage applied between the selected electrode of the electrode group and the recording medium. An electrode sleeve device for forming toner images for adhesion by electrostatic force, the device comprising:
An electrode sleeve device for forming a toner image, wherein the cylindrical sleeve has a thick part and a thin part forming a step, and the magnetic piece is fixed on the thin part at the position of the step.