JP3385485B2 - Discharge device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge device for charging a photosensitive member such as a copying machine or a laser printer of an electrophotographic system. 2. Description of the Related Art Conventionally, in a discharge device for electrostatically charging a photosensitive member by corona discharge in an image forming apparatus such as a copying machine or a laser printer of an electrophotographic system, air is forced to flow through a back plate. In some cases, a dust filter and an ozone removal filter are provided in the middle of the flow of air.
These filters have prevented the problem of incomplete image formation due to the deterioration of the discharge property due to the adhesion of dirt to the discharge wire, and the problem of uneven image formation due to non-uniform corona flow due to corona discharge. [0003] As described above, by forcibly flowing air through the back plate of the discharge device and providing a dust-proof filter and an ozone removal filter in the middle of the flow of air, the photosensitive element is exposed. A certain effect was recognized in absorbing dirt due to floating substances such as toner soaring from the body and oil vapor generated from a fixing device and preventing ozone from flowing out. That is, the discharge wire is contaminated by contaminants such as toner and oil vapor and the discharge property of the discharge wire is deteriorated, resulting in incomplete image formation, and corona flow due to ozone and the like generated by corona discharge. Although the problem of image unevenness due to uniformity could be prevented to some extent, it was not yet satisfactory. The present invention has been made to solve the above problems. That is, the present invention provides a high-quality, low-cost, and compact discharge device that does not have the problem of incomplete image formation due to contamination of the discharge wire and the problem of uneven image formation due to non-uniform corona flow due to corona discharge. It is intended for that purpose. SUMMARY OF THE INVENTION It is an object of the present invention to provide a discharge wire, a cleaning member for the discharge wire, and three sides of the periphery of the discharge wire except for a photoreceptor, and a side surface for discharging air. A back plate having a discharge port and provided with a guide groove for slidably guiding the cleaning member on a surface facing the photoreceptor, the back plate being attached in a longitudinal direction of the back plate, The air guide case, which is configured to be shut off from the outside air, is disposed between the outer wall of the air guide case and the guide groove, except for the outlet on the side surface of the air guide case.
Dust filter and the air guide case in the longitudinal direction.
Square provided at the end of a ventilation fan for exhausting air of the ozone removal filter and in the air guide casing,
An outlet for discharging air provided on the side surface of the back plate is provided at a position farther from the discharge wire when viewed from the photoconductor side, and the air guide case is provided.
With the ventilation fan provided at one end in the longitudinal direction ,
This is achieved by a discharge device, wherein air around the discharge wire is sucked into the air guide case from an outlet on a side surface of the back plate. Next, an embodiment of the present invention will be described with reference to the accompanying drawings and FIGS. FIG. 3 is a sectional view of an embodiment of the discharge device according to the present invention, showing a state where the discharge wire is being cleaned by the cleaning member. [0010] In FIG. 3, sensing by a back plate 12
The discharge wire 11 surrounded on three sides except the light body side is a cleaning member 30.
Cleaning is in progress. That is, the cleaning pad 31 for cleaning the discharge wire 11 is attached to the cleaning pad spring 32 attached to the cleaning pad base 33, and is attached so as to sandwich the discharge wire 11 with the cleaning pad spring 32. The cleaning pad base 33 is a back plate.
12 is slidably guided by a cleaning member guide groove 122H provided on the back plate bottom surface (surface facing the photoreceptor) 122 of the back plate. Thus, the discharge wire 11 is cleaned, and when not cleaned, the discharge wire 11 waits at a standby position at the end of the discharge device 10. Next, the discharge device of the present invention will be further described with reference to FIGS. FIG. 1 is a sectional view of an embodiment of a discharge device according to the present invention, and FIG. 2 is a sectional view taken along line XX of FIG. 1 and 2, an air guide case 13 is attached to the lower portion of the back plate 12 along the longitudinal direction of the back plate 12 as shown. The air guide case 13 is provided at the outlet 12 on the side of the back plate 12.
Except for 1H and 123H, it is configured to be shut off from the outside air (see FIG. 1). And the longitudinal direction of the air guide case 13
One end of the ozone removal filter 15, ventilation fan 16
Are attached as shown (see FIG. 2). Then, when the ventilation fan 16 is rotated to forcibly flow air in a direction indicated by an arrow F (a direction in which the air in the air guide case 13 is forcibly sucked), the flow on the outer wall of the air guide case 13 is reduced. The air flows in from the inlet 131H as shown by the arrow A, passes through the dustproof filter 14, passes through the inlet 132H, and flows into the cleaning member guide groove 122H provided on the back plate bottom surface 122H as shown by the arrow B as shown in FIG. (See FIG. 1) . Since the air at this time has passed through the dustproof filter 14, dirt on floating substances such as toner and oil vapor generated from the fixing device and the like in the air is absorbed here, and clean air is removed from the back plate 12. Will flow into it. The flow of air flows in the direction of arrow C, and the outlet 121 of the right side 121 of the back plate 12 of the back plate 12 flows.
H flows out to the air guide case 13 through the outlet 123H of the left side face 123 of the back plate, and passes through the air holes 135H and 136H in the direction of arrow D through the air holes 133H and 134H.
The air further flows through the ozone removal filter 15 in the direction E, and the air is forced to flow out in the direction of arrow F by the ventilation fan 16. [0018] Since the air at this time passes through the ozone removal filter 15, will be air such as ozone generated by corona discharge generated in the back plate 12 is absorbed to flow out, thus the ozone discharge unit Is prevented from flowing out to the outside, so that image unevenness due to non-uniform corona flow due to ozone or the like can be prevented. Further, it is possible to prevent the discharge wire and the like from being easily stained by the corona flow. Further, as a point of the present invention, air entering from the cleaning member guide groove 122H on the back plate bottom surface 122 passes through an outlet 121H on the right side 121 of the back plate and an outlet 123H on the left side 123 of the back plate to guide air. Case
It flows out to 13. That is, the air entering through the cleaning member guide groove 122H is viewed from the photosensitive member 20 and discharges air.
The air passes through the air outlets 121H and 123H farther away from the photoconductor, so that the toner flying from the photoconductor is not sucked. That is, the flow of air from the cleaning member guide groove 122H is increased, and the inflow of dirty air near the photoconductor 20 from between the photoconductor 20 and the back plate 12 can be reduced. Can be prevented from becoming dirty. Further, since the discharge wire 11 is stretched apart from the position of the air flow C, it is assumed that dirt of floating substances such as toner and oil vapor remains in the clean air flow C. Also, there is no fear that dirt adheres to the discharge wire 11. Therefore, there is no fear that the discharge property is deteriorated due to the contamination of the discharge wire 11 and the image formation is incomplete, and a high quality image forming apparatus can be realized. Further, since the cleaning member guide groove 122H provided on the back plate 12 is used as an air inlet, it is not necessary to newly provide the air, so the cost is not increased, and the cost is reduced accordingly. That means
This is useful for the compact discharge device. The discharge device can be used not only for charging the photosensitive member but also for discharging static electricity charged on the photosensitive member. According to the present invention, the discharge wire is less liable to be stained, so that the problem of incomplete image formation and the ozone generated by corona discharge are absorbed, so that high image quality and low image quality are obtained without any problem of image unevenness. A cost-effective and compact discharge device has been provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of a discharge device according to the present invention. FIG. 2 is a sectional view taken along the line XX of FIG. 1; FIG. 3 is a diagram showing a state during discharge wire cleaning of the discharge device according to the present invention. [Description of Signs] 10 Discharge device 11 Discharge wire 12 Back plate 121H, 123H Discharge port 122H Cleaning member guide groove 13 Air guide case 131H, 132H Inlet 14 Dustproof filter 15 Ozone removal filter 16 Ventilation fan 20 Photoconductor A, B, C, D, E, F Direction of air flow

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 15/02 G03G 15/16 102 H01J 19/00

Claims (1)

(57) [Claim 1] A discharge wire, a cleaning member for the discharge wire, and a periphery of the discharge wire surrounding three sides excluding the photoreceptor side, and a discharge port for air discharge on a side surface. A back plate provided with a guide groove for slidably guiding the cleaning member on a surface facing the photoreceptor; a back plate attached in a longitudinal direction of the back plate; The air outlet case is configured to be shut off from the outside air, and is disposed between the outer wall of the air guide case and the guide groove.
A dustproof filter , provided at one end in the longitudinal direction of the air guide case.
And ozone removal filter and the outlet of the air discharge provided with ventilation fan for exhausting air, the back plate side has in the air guide casing is viewed from the photoconductor side, the discharge A ventilating fan provided at one end in the longitudinal direction of the air guide case, and the air around the discharge wire is introduced into the air guide case from a discharge port on the side surface of the back plate , while being provided at a position farther from the wire. Discharge device characterized by suction.