JP3348055B2 - Static eliminator for image forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a static eliminator for an image forming apparatus, and more particularly, to a static eliminator used in combination with a transfer roller.

[Detailed Description of the Invention] An image forming apparatus such as a copying machine, a facsimile, a printer or the like transfers a photosensitive drum for forming a toner image and a toner image formed on the photosensitive drum to a sheet. And a transfer roller. In this type of image forming apparatus, a static eliminator is disposed adjacent to a downstream side of a transfer roller in a transport direction of a sheet on which a toner image is transferred. The static eliminator functions to remove unnecessary charges charged on the sheet on which the toner image has been transferred.

FIG. 1 is a schematic sectional view showing an arrangement relationship of a photosensitive drum 1, a transfer roller 2, and a charge removing device 3 in a conventional image forming apparatus. Arrow P indicates the direction of paper transport. The sheet is conveyed between the photosensitive drum 1 and the transfer roller 2, and at this time, the toner image formed on the surface of the photosensitive drum 1 is transferred to the sheet by the high voltage of the transfer roller 2. The sheet on which the toner image has been transferred is charged to the charge removing device
The paper is conveyed in the direction of arrow P while being guided by, and at this time, unnecessary electric charges on the paper are removed.

[0004] As shown in a partially exploded perspective view of FIG. 2, the charge removing device 3 includes a transport base 4 and a charge removing plate 5. The transport base 4 is integrally formed of an insulating material, for example, a resin, and has a frame 6 and a plurality of transport guide ribs 7. The plurality of transport guide ribs 7 are arranged at regular intervals in a direction orthogonal to the paper transport direction P, each of which is elongated in the paper transport direction, and guides the transported paper at its upper edge. A neutralizing brush 8 is attached to the neutralizing plate 5. The charge removing plates 5 are combined so as to be fitted between the transport guide ribs 7. Further, the static elimination plate 5 and the static elimination brush 8 are incorporated in the frame 6 so that the static elimination brush 8 is also positioned in the frame 6.

[0005]

In the conventional static eliminator, a part of the frame 6 has a back surface of the static elimination brush 8 (the transfer roller 2).
Since the wall portion is formed on the side (side), there is no fear that the bristles 9 of the neutralization brush 8 are bent toward the transfer roller 2 during the combination work. Therefore, when the static elimination plate 5 is combined with the transport base 4, all the bristles 9 of the static elimination brush 8 are in a state of being erected straight. However, there is a model in which the static elimination plate 5 cannot be combined with the transport base 4 from below the transport base 4 due to the restriction of the configuration of the image forming apparatus, particularly the configuration of the transport path. Some of such models require that the discharging brush 5 be combined with the transport base 4 from the upstream side in the paper transport direction P. During such a combination operation, the upstream edge of the transport guide rib 7 provided on the transport base 4 easily hits the neutralizing brush 8. This is because it is necessary to combine the neutralization brush 8 so as to enter the downstream side in the transport direction from the upstream edge of the transport guide rib 7. At this time, the upstream edge of the transport guide rib 7 and the bristles 9 of the neutralization brush 8 collide with each other. This is because the hair 9 may be overturned. In particular, since a plurality of transport guide ribs 7 are arranged, even if the assembling operation is performed with care, the bristles 9 of the neutralization brush 8 are located on the upstream edges of some transport guide ribs.
The hair 9 may fall down.

However, as shown in FIG. 3, when the bristles 9 of the neutralizing brush 8 fall, the fallen bristles 9 are transferred to the transfer roller 2.
, And the voltage of the transfer roller 2 may leak. The present invention has been made to solve such a problem. The present invention provides a static eliminator, in which a static elimination plate having a static elimination brush attached to a transport base is combined with a static elimination plate from an upstream side in a transport direction with respect to the transport base. It is an object of the present invention to provide a static eliminator of an image forming apparatus which is free from troubles such as falling down of the brush of the static elimination brush.

[0007]

According to a first aspect of the present invention, a sheet on which a toner image is transferred by a transfer roller is provided adjacent to a downstream side of a transfer roller in a sheet transport direction. A static eliminator for removing unnecessary electric charges, which are arranged at regular intervals in a direction perpendicular to the paper transport direction, each of which is elongated in the paper transport direction, and is transported at an upper edge thereof. Having a plurality of transport guide ribs for guiding the, a transport base integrally formed of an insulating material, and a static elimination plate to which a static elimination brush is attached,
The static elimination plate is combined with the transport base from the upstream side in the transport direction, and the transport direction upstream of the transport guide ribs can be separated from the static elimination brush attached to the static elimination plate when the static elimination plate is combined. The static eliminator of the image forming apparatus is characterized by having a pointed tip shape as described above.

According to a second aspect of the present invention, there is provided the static eliminator according to the first aspect, wherein the static elimination plate has a plurality of static elimination surfaces arranged at equal intervals, and each of the static elimination surfaces is provided between each transport guide rib. , The static elimination plate is combined with the transport base from the upstream side in the transport direction to provide a static eliminator for the image forming apparatus. According to the configuration of claims 1 and 2, when the static elimination plate is combined with the transport base, the distal end of each transport guide rib provided on the transport base, specifically, the distal end facing the upstream side in the transport direction. Even if the static elimination brush collides with the portion, the static elimination brush is not fallen by the tip. That is, the tip has a pointed shape, and even if the static elimination brush collides, the brushes are not separated and the respective hairs constituting the brush do not fall down.

In an image forming apparatus, generally, a static eliminator is disposed adjacent to a downstream side of a transfer roller. This static eliminator removes unnecessary charges that are charged on the sheet on which the toner image has been transferred by the transfer roller. The static eliminator generally includes a guide formed of an insulating material for guiding conveyance of a sheet, and a static elimination plate and a static elimination brush formed of a conductor combined with the guide. Although both are combined at the time of manufacturing, there is a configuration in which the static elimination plate can be combined only from the transfer roller side with respect to the transport base due to restrictions on the form of the transport path.

In such a configuration, when the static elimination plate is combined with the transport base, the bristles of the static elimination brush attached to the static elimination plate may collide with the transport base and fall or bend. In particular, when the transport base is provided with the transport guide ribs, the upstream edge of the transport guide ribs in the transport direction extends to the vicinity of the transfer roller, so that the transport guide ribs easily collide with the neutralizing brush. Once the brush of the static elimination brush is fallen, it tends to have a fall habit. If it falls on the transfer roller side, it may come into contact with the transfer roller, causing problems such as releasing the potential of the transfer roller.

According to the configuration of the present invention, even when the neutralizing brush contacts the leading end of the transport guide rib during the operation of combining the neutralizing plate with the transport base, the leading end of the transport guide rib is sharp and the neutralizing brush is separated. And the static elimination brush does not fall down. Therefore, according to the present invention,
It is possible to provide a static eliminator for an image forming apparatus which has a good yield at the time of assembling work and is easy to assemble.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 4 is a schematic sectional view of a static eliminator according to an embodiment of the present invention, and FIG. 5 is a partially exploded perspective view of the static eliminator. Referring to FIGS. 4 and 5, the static eliminator 10 according to the present embodiment is configured such that the transfer roller 2
Adjacent to the downstream side. The static elimination device 10 includes a plurality of transport guide ribs 11, a static elimination plate 12, and a static elimination brush 13. The transport guide ribs 11 are arranged at regular intervals in a direction orthogonal to the paper transport direction P, and each of them is elongated in the paper transport direction P. The transport guide rib 11 guides the paper transported at its upper edge. The lower part of the transport guide rib 11 is the base plate 1.
4 and one. That is, the base plate 14
A plurality of conveyance guide ribs 11 are provided upright.

The base plate 14 constitutes, for example, a part of an outer wall of the image forming apparatus, and is formed of an insulating resin. Therefore, the transport guide rib 11 is also made of an insulating resin. The base plate 14 is provided so as to be openable and closable about a fulcrum (not shown), and is opened when paper is jammed. The transfer roller 2 may be attached to the base plate 14 in addition to the charge removing device 10. Also, the transfer roller 2
One of the pair of registration rollers on the upstream side may be attached. Or the static eliminator 10
One of the rollers of the fixing device disposed downstream of the fixing device may be attached.

In this embodiment, since the base plate 14 constitutes a part of the outer wall of the copying machine, when the static elimination plate 12 is combined with the transport guide rib 11, the static elimination plate 12 is positioned below the transport guide rib 11. Cannot be combined. Therefore, the neutralization plate 12 is combined with the transport guide rib 11 from the upstream side in the transport direction. A charge removing brush 13 is attached to the charge removing plate 12 by, for example, a mounting screw 15 or the like. Both the charge removing plate 12 and the charge removing brush 13 are formed of a conductive material.

After the static elimination plate 12 is combined with the transport guide rib 11, the static elimination plate 12 is fixed to the base plate 14 by mounting screws 16. Although not shown, the static elimination plate 12
Alternatively, a grounding lead wire is connected in connection with the mounting screw 16. The feature of this embodiment is as shown in FIG.
The point that the upstream side of the transport guide rib 11 in the paper transport direction has a pointed tip shape 17. With such a pointed tip shape 17, when the static elimination plate 12 is combined with the transport guide rib 11 from the upstream side in the sheet transport direction, the bristles 18 of the static elimination brush 13 attached to the static elimination plate 12 are moved even if the transport guide rib 11 is used. The hairs 18 are separated by the pointed tip shape 17 even if they are combined in such a way as to hit the upstream end of the hair. Therefore, the bristles 18 of the charge removing brush 13 do not fall down during assembly.

Therefore, according to the present invention, the assembling is easy, and the bristles 18 of the neutralizing brush 13 do not fall down when the assembling is completed, so that the yield during the assembling work is good. In this embodiment, the transport guide rib 11 is described as being integrated with the base plate 14. However, the transport guide rib 11 is not integrated with the base plate 14. for,
The present invention is also applicable to a combination of a static elimination plate from the upstream side in the paper transport direction. What is necessary is just to make the shape of the front-end | tip of the conveyance guide rib 11 in the conveyance direction upstream in such a conveyance base sharp like the embodiment of this invention.

The present invention is not limited to the embodiment described above, and various changes can be made within the scope of the claims.

[Brief description of the drawings]

FIG. 1 is an illustrative sectional view showing an arrangement relationship of a photosensitive drum, a transfer roller, and a charge removing device in a conventional image forming apparatus.

FIG. 2 is a partially exploded perspective view of a conventional static eliminator.

FIG. 3 is an illustrative view showing a state in which the brush of the static elimination brush has fallen;

FIG. 4 is an illustrative sectional view of a static eliminator of the image forming apparatus according to the embodiment of the present invention;

FIG. 5 is a partially exploded perspective view of the static eliminator according to the embodiment of the present invention.

[Explanation of symbols]

 2 Transfer Roller 10 Static eliminator 11 Conveyance guide rib 12 Static elimination plate 13 Static elimination brush 17 Tip shape 18 Hair

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 15/14 101 G03G 15/16 G03G 21/16

Claims (2)

(57) [Claims] 1. A static eliminator, which is adjacent to a downstream side of a transfer roller with respect to a sheet transport direction and removes unnecessary charges charged on a sheet onto which a toner image has been transferred by the transfer roller. It is arranged at regular intervals in the direction perpendicular to the transport direction, each is elongated in the paper transport direction, and has a plurality of transport guide ribs for guiding the paper transported at the upper edge thereof, and is integrally molded with an insulating material. A transfer base, and a static elimination plate to which a static elimination brush is attached, wherein the static elimination plate is combined with the conveyance base from an upstream side in the conveyance direction, and an upstream of the conveyance guide rib in the conveyance direction is a static elimination plate. A static elimination device for an image forming apparatus, wherein the static elimination device has a sharpened tip so that a static elimination brush attached to the static elimination plate can be swept when combined. 2. The static eliminator according to claim 1, wherein the static elimination plate has a plurality of static elimination surfaces arranged at equal intervals, and each of the static elimination surfaces is positioned between the transport guide ribs. A static eliminator for an image forming apparatus, wherein the static elimination plate is combined with a transport base from an upstream side in a transport direction.