JPH06149015A - Corona discharger - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a corona discharger that enables the same discharger to be used for models with different charging conditions. A corona discharger including a corona discharger body facing a photoconductor and a guide rail that detachably supports the discharger body, the guide rail having a U-shaped cross section. It is a member and has a plurality of pairs of guide projections on the inner walls facing each other, and the corona discharger main body is composed of a casing having a substantially U-shaped cross section and a corona wire stretched in the casing. By inserting the guided portion laterally protruding from both side walls of the casing into the insertion space between the guide protrusions in the guide rail, the corona discharger main body can be inserted and attached. By selecting the space, the distance of the corona discharger to the photoconductor was made variable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a corona discharger such as a charging device used in an image forming section of an image forming apparatus utilizing an electrophotographic process.

[0002]

2. Description of the Related Art In an image forming apparatus utilizing an electrophotographic process such as a copying machine, a printer and a facsimile machine, for example, a charger and an exposure are provided along a rotating direction of a photosensitive drum having a photosensitive layer on its outer peripheral surface. The developing unit, the developing device, the transfer charger, the separation charger, the cleaning unit, the charge eliminating lamp and the like are sequentially arranged. The charger is
It has a structure in which a corona wire is stretched along the longitudinal direction inside a long casing having a substantially U-shaped cross section, and the surface of the photosensitive drum is uniformly negatively charged by utilizing the corona discharge of the corona wire. In the exposure section, the potential of the exposed section is dropped by irradiating the charging section with the reflected light of the document and other optical image information. An electrostatic latent image is formed on this exposed portion. The developing device develops an image by attaching toner to the electrostatic latent image portion. The transfer charger transfers the visible image onto the recording sheet by charging the corona discharge while facing the visible image on the photoconductor with the conveyed recording sheet sandwiched therebetween. The transferred recording paper is subjected to AC neutralization by a separation charger integrated with the transfer charger, and separated from the photosensitive drum. Both the transfer charger and the separation charger have a configuration similar to that of the charging charger.

However, in a conventional corona discharger such as a charger, the discharger is fixed so that the distance from the surface of the photoconductor is constant, so that the linear velocity of the photoconductor is charged. It was difficult to transfer the discharger as it is between models with different conditions. In other words, even if the model has the same distance between the discharger and the photoconductor, if the charging conditions are different, it is necessary to use another discharger with different functions such as output, and use the same charger. In this case, it was necessary to change the member holding the discharger in order to change the distance between the photosensitive member and the photosensitive member.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide a corona discharger capable of diverting the same discharger among models having different charging conditions.

[0005]

To achieve the above object, the present invention provides a corona discharger comprising a corona discharger body facing a photoreceptor and a guide rail for detachably supporting the discharger body. The guide rail is a member having a U-shaped cross section, and has a plurality of pairs of guide protrusions on the inner walls facing each other, and the corona discharger main body is a casing having a substantially U-shaped cross section. , A corona wire stretched in the casing, and the guided portion protruding outward from both side walls of the casing is inserted into the insertion space between the guide protrusions in the guide rail, so that the corona discharge is prevented. The main body of the corona discharger can be attached and the distance between the corona discharger and the photoconductor can be changed by selecting the insertion space. And a guide rail for detachably supporting the corona discharger, wherein the guide rail is a member having a U-shaped cross section having guide protrusions on inner walls facing each other. The main body is composed of a casing having a substantially U-shaped cross section and a corona wire stretched in the casing, and a guided portion protruding outward from both side walls of the casing is slid by a guide protrusion in the guide rail. By freely supporting it, the corona discharger main body can be inserted and attached, and the guide rail is supported so as to be movable back and forth with respect to the image forming apparatus main body side.

The present invention will be described in detail below with reference to the accompanying drawings. 1 (a) and 1 (b) are an exploded perspective view showing a configuration of a first embodiment of the present invention and a diagram showing a positional relationship with a photoconductor. This corona discharger includes a discharger main body 1 and a discharge main body. The guide rail 2 is a long member having a U-shaped cross section, and a plurality of pairs of guide protrusions 3 are provided on the inner walls facing each other. is doing. The corona discharger main body 1 is composed of a casing 4 having a substantially U-shaped cross section and a corona wire 5 stretched in the casing 4. A guided portion 4a is provided so as to project outward from both end portions). By inserting this guided portion 4a between the guide protrusions 3 in the guide rail 2, the corona discharger main body 1 can be inserted and detached by pulling it out. Also,
By selecting the insertion spaces 3a and 3b defined between the guide protrusions 3 and inserting the discharger main body 1, the distance from the photoconductor 6 can be changed according to the charging conditions of the model. Becomes Although only two insertion spaces are provided in this embodiment, this is an example and it is of course possible to provide three or more spaces.

As described above, in the first embodiment, since the guide rails fixed to the main body of the image forming apparatus are formed with a plurality of insertion spaces 3a, 3b, ... With different distances from the photoconductor, It is possible to select the distance from the photosensitive member when attaching the first type, and it is possible to apply the same type of discharger to the image forming units of different models.

Next, FIG. 2 is a structural explanatory view of a second embodiment of the present invention. The guide rail 10 has a guide rail main body 11 having guide projections 11a as shown in the inner walls facing each other, and the main body. 11 and a bolt 12 integrated in a proper place on the upper surface of the bolt 11. The bolt 12 is inserted into a hole 13a formed in a mounting plate 13 on the image forming apparatus main body side, and is attached by tightening an upper end portion with a nut 14. It is fixed to the plate 13. The distance between the mounting plate 13 and the guide rail body 10 is determined by adjusting the tightening position of the bolt with the nut 14. Discharger 1
Has a configuration similar to that of the first embodiment, and the mounting is completed by inserting the guided portion 4a into the insertion space 11b of the guide rail main body 11.

In the second embodiment, a mechanism composed of bolts and nuts is adopted as means for arranging the guide rail main body so that it can move forward and backward with respect to the mounting plate 13. However, this is only an example, and instead of bolts. On the outer peripheral surface of the guide rail, rods having grooves, holes, or protrusions formed at predetermined intervals in the axial direction are projected from the upper surface of the guide rail, and instead of nuts, clip members capable of engaging with the grooves, holes, or protrusions The position of the guide rail may be variably configured by engaging the above. As described above, in the second embodiment of the present invention, the distance between the guide rail 10 holding the discharger 1 and the photosensitive member can be arbitrarily changed by changing the tightening position of the nut with respect to the bolt protruding from the guide rail. Since I changed it to
The distance between the discharger 1 supported by the guide rail and the photosensitive member can be adjusted to an arbitrary value, and the same discharger can be diverted between models having different charging conditions, which is economical. Can be increased.

Next, FIG. 3 shows a third embodiment of the present invention.
Two rotary shafts 6a protruding from the center of the photosensitive drum 6,
A front side plate 20 and a rear side plate 21 that rotatably support 6b.
Positioning holes A, A ', B, and B'are provided at appropriate positions. Positioning holes corresponding to each other are A and A ', B and B'
Are set to have different heights. On the other hand, the connecting member 26 is hung downward from the front end of the casing of the corona discharger 25, and the plurality of protrusions 27 projecting from the connecting member 26 are positioned in the positioning holes A provided in the front plate 21. , B can be selectively fitted respectively. Also,
A plurality of protrusions 28 are projected from a proper position on the rear end portion of the casing of the discharger 25, and each protrusion 28 can be selectively fitted into the positioning holes A ′ and B ′ provided in the rear plate 20. There is. Therefore, by appropriately setting the positional relationship between the positioning holes A, A ′, B, B ′ and the protrusions 27, 28, the positional relationship of the discharger 25 with respect to the surface of the photoconductor 6 can be set in multiple steps. Can be changed to. In addition, in the above embodiment, since two sets of positioning holes are provided, the number of stages can be changed only in two stages. Further, a protrusion may be provided on the side plate side and a hole may be provided on the discharger side.

[0011]

As described above, according to the present invention, the casing constituting the discharger is detachably attached to the guide rail or the like, and the position of the casing with respect to the guide rail or the guide rail with respect to the photoconductor is set. Since the distance can be changed in multiple stages, the same discharger can be diverted and applied between models having different charging conditions.

[Brief description of drawings]

1A and 1B are a perspective view showing a configuration of a discharger according to a first embodiment of the present invention and a diagram showing a positional relationship between an assembled discharger and a photoconductor.

FIG. 2 is an exploded view showing a configuration of a second embodiment of the present invention.

FIG. 3 is a configuration explanatory diagram of a third embodiment of the present invention.

[Explanation of symbols]

1 discharger body, 2 guide rails, 3 guide protrusions,
3a, 3b insertion space, 4 casing, 4a guided part, 5 corona wire, 6a, 6b rotating shaft, 1
0 guide rail, 11 guide rail body, 11a
Guide protrusion, 11b insertion space, 12 bolts, 1
3 Mounting plate, 13a hole, 14 Nut, 20, 2
1 side plate, 25 discharger, 26 continuous member, 27 protrusion, 28 protrusion,

Claims (2)

[Claims] 1. A corona discharger body facing a photoconductor,
A corona discharger including a guide rail that detachably supports the discharger main body, the guide rail being a member having a U-shaped cross-section, and a guide protrusion on the inner walls facing each other. The corona discharger main body has a plurality of pairs, and the corona discharger main body is composed of a casing having a substantially U-shaped cross section and a corona wire stretched in the casing, and the guided body protruding outward from both side walls of the casing. By inserting the portion into the insertion space between the guide protrusions in the guide rail, the corona discharger main body can be inserted and the distance between the corona discharger and the photoconductor is selected by selecting the insertion space. A corona discharger characterized by a variable configuration. 2. A corona discharger body facing the photoconductor,
A corona discharger configured with a guide rail that detachably supports the discharger main body, the guide rail being a member having a U-shaped cross-sectional shape having guide protrusions on inner walls facing each other. The main body of the corona discharger comprises a casing having a substantially U-shaped cross section and a corona wire stretched in the casing. A guided portion protruding outward from both side walls of the casing is provided in the guide rail. The corona discharger is slidably supported by the guide projections so that the main body of the corona discharger can be inserted therein, and the guide rail is supported so as to be movable back and forth with respect to the main body of the image forming apparatus. .