JPH04294369A - Image forming device provided with exhaust device - Google Patents

Abstract

PURPOSE:To efficiently exhaust ozone generated by an electrostatic charger to the outside of a machine without staining a discharge wire and to produce a device for exhausting the ozone to the outside of the machine at low cost. CONSTITUTION:Aperture parts 18 and 19 are respectively formed at both ends in the longitudinal direction of an electrostatic charger case 12 in which the discharge wire 14 of the electrostatic charger 5 is stretched and provided, and insulating elastic sheets 13 and 13 are attached over the entire length of both side surfaces 12a (which is not shown in the figure 1) and 12b of the case 12 so that a leading edge part 13a may contact the surface of a photosensitive drum 4, and a gap part left between the electrostatic charger 5 and the photosensitive drum 4 is hermetically sealed by sealing materials 23 and 26 so as to form a closed space 25 between the charger 5 and the drum 4. A fan 28 is provided on one aperture part 19 side, and the ozone evolved in the closed space 25 is efficiently exhausted to the outside of the machine.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, etc., which is equipped with an exhaust device for discharging ozone generated during operation of a charger.

0002

2. Description of the Related Art Conventionally, image forming apparatuses equipped with an exhaust device for discharging ozone generated during operation of a charger to the outside of the apparatus have been disclosed, for example, in Japanese Utility Model Application Publication No. 1-120157 and Japanese Patent Application Laid-open No. 1983-12015. As seen in Publication No. 90457, the ozone generated by the charger is sucked from the top of the charger,
There is one that discharges it outside the machine through an ozone filter.

[0003] Also, as seen in Japanese Patent Application Laid-Open No. 163472/1983, air is blown from the top of the charger,
Some systems use the air blowing fan and another fan to exhaust ozone generated by the charger to the outside of the machine via an ozone filter.

0004

[Problem to be Solved by the Invention] However, in the case of the former type of exhaust device, the ozone generated in the charger passes through the discharge wire portion and is sucked toward the top of the charger. In normal cases, a cleaning device, a developing device, etc. are installed around the photoconductor, and floating toner that leaks from these devices and scatters is sucked together with ozone, and when it adheres to the discharge wire, There were cases where discharge unevenness occurred and images tended to deteriorate (blur).

[0005] Furthermore, in the case of the latter type of exhaust system,
Since air is blown from the top of the charger, the discharge wire will not get dirty, but the ozone generated from the charger will be diffused into the machine by the air blown, so the ozone filter must be used to efficiently collect the diffused ozone. As a result, some ozone tends to leak directly to the outside of the machine through gaps in the exterior cover, etc. Furthermore, since two fans are used, the cost is high.

[0006] This invention was made in view of the above-mentioned problems, and its purpose is to make it possible to efficiently discharge ozone generated by a charger to the outside of the machine without contaminating the discharge wire. do. Another object of the present invention is to make it possible to inexpensively manufacture a device for discharging the ozone to the outside of the machine.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an image forming apparatus as described above, in which openings are provided at both longitudinal ends of a case in which the discharge wire of the charger is stretched. At the same time, an insulating elastic sheet is attached to both sides of the case so that its tip is in contact with the surface of the photoreceptor over its entire length, and the remaining gap between the charger and the photoreceptor is filled. A closed space is formed between the charger and the photoreceptor by sealing the photoreceptor with a sealing material that can be slid into contact with the photoreceptor, and a fan for intake or exhaust is provided on one opening side of the case. .

Further, in the image forming apparatus equipped with the exhaust device, the charger is made removable from the main body of the image forming apparatus, and an ozone filter is attached to the opening on the exhaust side of the charger.

[0009]

[Operation] According to the image forming apparatus equipped with the exhaust device configured as described above, a closed space is formed between the charger and the photoreceptor, and ozone generated from the charger is released into the closed space. Therefore, when the fan installed on one side of the charger's opening is rotated, outside air is drawn into the closed space through one opening, and it is discharged along with the air in the closed space through the other opening. Therefore, the ozone released in the closed space can be efficiently discharged to the outside of the machine.

Furthermore, if the charger is made detachable from the main body of the image forming apparatus and an ozone filter is attached to the opening on the exhaust side of the charger, when the charger is removed from the main body of the image forming apparatus, Since the ozone filter is also removed together with the charger, the ozone filter can be easily replaced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing the main parts of an image forming apparatus equipped with an exhaust device, which is an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing the vicinity of a photoreceptor drum of a copying machine as the image forming apparatus. be.

In this copying machine, as shown in FIG. 2, paper P fed from a paper feed cassette 2 inserted into the side of the main body 1 of the apparatus is timed by a registration roller 3 and then exposed to light. It is transported to the body drum 4.

The surface of the photosensitive drum 4 is charged by a charger 5, and an image corresponding to the original is formed thereon by an optical system 6 to form a latent image, which is converted into toner by a developing device 7. is attached and visualized (toner image).

The toner image is transferred onto the paper P transported by the transfer charger 8, and then transported to a fixing unit (not shown) by the transport belt 9, and then discharged outside the machine. The toner remaining on the photoreceptor drum 4 is removed by the cleaning device 11 and collected in the toner collection chamber.

Further, as shown in FIG. 1, this copying machine is provided with an exhaust device 10 close to the surface of the photoreceptor drum 4 for discharging ozone generated while the charger 5 is in operation. ing.

The exhaust device 10 is constructed using some of the parts constituting the charger 5, and includes a front end block 16 and a rear end block 17 formed at both ends of the charger case 12 with an insulating material such as resin. are fixed together,
Openings 18, 1 in the front and rear end blocks 16, 17
9 (four locations each) are formed as shown in FIGS. 3 and 4, so that both longitudinal ends of the charger 5 are open.

As shown in FIG. 1, a discharge wire 14 is stretched approximately at the center of the front end block 16 and rear end block 17 with a predetermined tension, and its right end side is connected to the electrode 21. Further, an insulating elastic material formed of, for example, a urethane sheet is provided on both longitudinal side surfaces 12a (FIG. 3) and 12b of the charger case 12 so as to bring the tip portion 13a into contact with the surface of the photoreceptor drum 4 over the entire length thereof. sheet 1
3 and 13 are installed respectively.

Furthermore, the remaining gap between the charger 5 and the photoreceptor drum 4 is filled by attaching a sealing material 23, such as a sponge, which can slide onto the photoreceptor drum 4, to the rear plate 24 by adhesive. In addition to sealing, a sealing material 26 similar to the sealing material 23 is attached to the lower surface of the front end block 16 by adhesive to form a closed space 25 between the charger 5 and the photosensitive drum 4.

Then, when the charger 5 is rotated in the forward direction, outside air is introduced into the closed space 25 from the opening 18 on the front end block 16 side, and the outside air is transferred to the opening 19 side of the rear end block 17. A fan 28 is provided to discharge the air from the air. Note that the opening 18 is arranged near an opening formed in an exterior cover (not shown) of the main body of the apparatus in order to easily take in outside air.

The fan 28 is connected to the opening 24 of the rear plate 24.
It is disposed in a duct 27 attached to a, and is rotated by a motor (not shown). And that duct 27
A removable and replaceable ozone filter 29 is attached to the outlet portion of the ozone filter.

Note that this charger 5 is attached to the device main body 1 (see FIG. 2).
), and in the installed state shown in FIG. 1, the upper surface part facing the ceiling is covered by the mounting plate 20 on the device main body 1 side as shown in FIG. 2, and the right end side in FIG. The upper part is made of a sealing material 31 similar to the sealing material 23 attached to the rear side plate 24 by adhesive, and the upper part on the left side is a protruding part 16a that makes the front end block 16 protrude upward.
As a result, the aforementioned closed space 25 is formed between the charger 5 and the photosensitive drum 4.

Further, 32 in FIG. 1 is a connector for connecting the discharge wire 14 to a high voltage power source.

In this copying machine, when the fan 28 of the exhaust device 10 rotates forward to start copying, since there is a closed space 25 between the charger 5 and the photosensitive drum 4, that area becomes negative pressure, and Outside air is sucked in from the opening 18. Therefore, even if ozone is generated by applying a high voltage to the discharge wire 14 of the charger 5, the ozone is moved in the direction of arrow B along with the air introduced into the closed space 25 from outside the machine by the suction force by the fan 28. When it passes through the ozone filter 29, carbon dioxide gas (Co2
) and are discharged outside the aircraft.

As described above, in this embodiment, since a closed space is formed between the charger 5 and the photoreceptor drum 4, the particles scattered from the cleaning device 11 and the developing device 7 (FIG. 2) may damage the photoreceptor. Since the toner floating near the drum 4 is difficult to enter the closed space, the discharge wire is not contaminated by the floating toner, so uneven discharge does not occur.

FIG. 5 is a sectional view showing only the vicinity of the main parts of another embodiment of the present invention, and parts corresponding to those in FIG. 1 are designated by the same reference numerals. In the copying machine equipped with this exhaust device, the charger 5 is removable from the main body of the copying machine as in the embodiment shown in FIG. The ozone filter 29 is eliminated, and instead, an ozone filter 39 shown in FIG. 6 is detachably installed in the opening 19 on the exhaust side (right side in FIG. 5) of the charger 5.

Therefore, when the entire charger 5 is moved to the left in FIG. 5 and removed from the main body of the copying machine, the charger case 12 and the rear end block 17 are separated from the rear side plate 24 while being integrated. The ozone filter 39 is then pulled out together with the ozone filter 39 inserted into the end of the opening 19 of the end block 17, so there is no need to remove the rear side plate 24 when replacing the dirty ozone filter 39. Replacement work can be done easily.

Further, the image forming apparatus equipped with the exhaust device according to the present invention eliminates the ozone filter 29 in FIG.
An ozone filter similar to the ozone filter 39 provided in the opening 17 of the embodiment shown in FIG. By rotating in the opposite direction to that in the embodiment of FIG.
Even if air is taken in from the duct 27 into the closed space 25 in a direction opposite to the arrow B, the air is discharged together with ozone through the ozone filter and out of the machine from the opening 18 on the exhaust side. good.

In this way, the air pressure inside the closed space 25 will be higher than that outside the closed space 25 while the fan 28 is operating, so that the cleaning device 11 of FIG.
Toner scattered from the developing device 7 and the like and floating near the surface of the photoreceptor drum 4 becomes more difficult to enter the closed space 25.

In each of the above embodiments, examples using a drum-shaped photoreceptor have been described, but the present invention can be similarly applied to an image forming apparatus equipped with a belt-shaped photoreceptor.

[0030]

[Effects of the Invention] As explained above, according to the present invention, the ozone generated by the charger is released into the closed space between the charger and the photoreceptor, and it is formed at one end of the charger. Since the outside air taken in through the opening is discharged to the outside of the machine through the other opening, toner scattered from the cleaning device, developing device, etc. and floating near the surface of the photoconductor is difficult to enter into the closed space. Since the discharge wire is not contaminated by the floating toner, and the generated ozone can be efficiently collected and discharged, abnormal images due to uneven charging do not occur. Then, there is one fan for intake or exhaust.
Since only one piece is required, the device can be manufactured at low cost.

Furthermore, if the charger is made detachable from the main body of the image forming apparatus and an ozone filter is attached to the exhaust side opening of the charger, the ozone released into the closed space will pass through the ozone filter. This allows ozone to be discharged outside the machine in a decomposed state, preventing ozone from directly leaking out of the machine.

Since the ozone filter has a limited lifespan, it is necessary to replace it periodically, but when the charger is pulled out from the main body of the image forming apparatus, the ozone filter is attached to the opening on the exhaust side. Since the ozone filter is taken out together with the ozone filter in the same state, the dirty ozone filter can be easily replaced without removing the outer cover or the like, which improves maintainability.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main parts of an image forming apparatus equipped with an exhaust device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing the vicinity of a photosensitive drum of a copying machine, which is also an image forming apparatus.

FIG. 3 is a sectional view taken along line AA in FIG. 1;

4 is a left side view showing part of the charger 5 and photosensitive drum 4 in FIG. 1. FIG.

FIG. 5 is a sectional view showing only the vicinity of the main part of another embodiment of the present invention.

6 is a perspective view showing an ozone filter attached to the exhaust side opening of the charger of the embodiment shown in FIG. 5; FIG.

[Explanation of symbols]

1 Device body
4 Photosensitive drum 5 Charger
10 Exhaust device 11
Cleaning device 12 Charger case 12a, 12b side surface
13 Insulating elastic sheet 13a Tip part
14 Discharge wire 16 Front end block
17 Rear end block 18, 19 Opening 2
3, 26, 31 Sealing material 28 Fan
29,39 Ozone filter P paper

Claims (2)

[Claims] 1. An image forming apparatus in which a charger is disposed close to the surface of a photoreceptor, wherein openings are formed at both ends of a case in a longitudinal direction to which a discharge wire of the charger is stretched, and An insulating elastic sheet is attached to each side of the case so that its tip is in contact with the surface of the photoreceptor over its entire length, and the remaining gap between the charger and the photoreceptor is covered with the photoreceptor. forming a closed space between the charger and the photoreceptor by sealing it with a sealing material that can slide into contact with the body;
An image forming apparatus equipped with an exhaust device, characterized in that an intake or exhaust fan is provided on one opening side of the case. 2. An image forming apparatus equipped with an exhaust device according to claim 1, wherein the charger is removable from the main body of the image forming apparatus, and an ozone filter is attached to the opening on the exhaust side of the charger. An image forming apparatus equipped with an exhaust device characterized by: