JPH0540387A - Image formation device equipped with evacuating apparatus - Google Patents

Abstract

PURPOSE:To prevent image quality from decreasing by efficiently collecting and discharging ozone that an electrostatic charger generates without staining a discharging wire with toner, etc., which is suspended at the periphery. CONSTITUTION:On the rotation-directional downstream side of the photosensitive drum 4 of the electrostatic charger 5 an ozone collection passage 25 which is opened opposite the photosensitive drum 4 is formed and a suction device 30 is provided at one end of the passage to suck the ozone generated by the electrostatic charger into the ozone collection passage 25 and discharge the ozone without passing it through the casing 12 of the electrostatic charger in a discharging process, thereby preventing the discharging wire 14 from being made dirty with the suspended toner. Further, the electrostatic charger 5 is provided to a device main body detachably and an ozone filter is fitted to the ozone collection passage 25 detachably to enable the ozone filter to be replaced at the same time with the detachment of the electrostatic charger 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer, a facsimile, etc. having an exhaust device for collecting and discharging ozone generated during operation of a charger arranged around a photosensitive drum together with air. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a high voltage is applied to a discharge wire of a charger to charge a photoconductor, and ozone is generated at that time. If the amount of this ozone is large, uneven charging occurs and the image is blurred.

Therefore, normally, in order to remove the ozone, the fan of the suction device is rotated to suck the ozone,
By passing it through an ozone filter, it is decomposed into carbon dioxide and exhausted outside the machine.

As an image forming apparatus provided with an exhaust device for decomposing ozone generated during operation of the charger and discharging it to the outside of the apparatus, for example, Japanese Utility Model Laid-Open No. 1-120157 and Japanese Patent Application Laid-Open No. 64-90457. As can be seen in Japanese Patent Publication, ozone generated by the charger is sucked from the top of the charger,
There is a device in which it is discharged to the outside through an ozone filter.

Further, as seen in Japanese Patent Laid-Open No. 63-163472, air is blown from above the charger,
There is also a fan in which ozone generated by the charger is sucked by a fan other than the air blowing fan and is discharged to the outside of the machine through an ozone filter.

[0006]

However, in the case of the exhaust device such as the former, ozone generated in the charger is sucked toward the upper portion of the charger through the portion of the discharge wire. In a normal case, a cleaning device, a developing device, etc. are provided around the photoconductor, and the floating toner leaked and scattered from these devices is sucked together with the ozone and adheres to the discharge wire. There have been cases where uneven discharge easily occurs and the image quality is easily degraded (blurred).

Further, in the case of the latter exhaust system,
Since the air is blown from the top of the charger, the discharge wire is not contaminated, but the ozone generated from the charger diffuses into the machine due to the blown air, so the diffused ozone is collected efficiently and the ozone filter is used. It becomes difficult to discharge the ozone to the outside of the machine through the result, and as a result, a part of ozone is likely to leak to the outside of the machine directly from a gap such as an exterior cover. Further, since two fans are used, the cost becomes high.

The present invention has been made in view of the above problems, and efficiently collects and discharges ozone generated by the charger without contaminating the discharge wire with toner floating in the vicinity thereof. It is an object to prevent the image quality from being deteriorated due to blurring of the image. Also,
It is also intended that the exhaust device can be manufactured at low cost and the exchangeability of the ozone filter is improved.

[0009]

In order to achieve the above object, the present invention provides an image forming apparatus as described above, comprising:
On the downstream side of the charger in the rotation direction of the photoconductor drum, an ozone recovery passage having an open surface facing the photoconductor drum is formed integrally with the casing of the charger along the axial direction of the photoconductor drum. A suction device is provided at one end.

The ozone recovery passageway may be configured such that the opening width facing the photosensitive drum is gradually widened from one end where the suction device is provided to the other end.

Further, it is effective that the image forming apparatus is provided with an elastic sealing material which is in sliding contact with the outer peripheral surface of the photosensitive drum on one side surface of the ozone recovery passage on the downstream side in the rotational direction of the photosensitive drum. .. Further, it is more effective if a charger is detachably attached to the apparatus main body, and an ozone filter is detachably attached to the ozone recovery passage of the charger on the open side facing the photoconductor drum. It is advisable to tilt the ventilation direction towards the suction device.

[0012]

According to the image forming apparatus having the exhaust device configured as described above, the ozone generated by the operation of the charger is activated by operating the suction device provided at one end of the ozone recovery passage. The ozone recovery passageway is sucked into the ozone recovery passageway from a surface facing the photoconductor drum, and the ozone recovery passageway moves along the axial direction of the photoconductor drum and is discharged.

Therefore, since ozone is discharged through the ozone recovery passage dedicated to ozone discharge without passing through the casing of the charger in the discharging process, the discharge wire is not in the passage of the ozone, and is less likely to become dirty.

Further, if the opening width of the ozone recovery passageway facing the photosensitive drum is gradually widened from one end where the suction device is provided to the other end, it is strong in the portion close to the suction device. Ozone is sucked into the ozone recovery passageway through its narrow opening due to the strong suction force, and weak suction force is generated in the distant portion, but since the opening width is wide, ozone is easily sucked into the recovery passageway. Ozone can be efficiently sucked uniformly over the entire length.

Further, if an elastic seal member is provided on one side surface of the ozone recovery passage on the downstream side in the rotation direction of the photoconductor drum, the elastic main body slidingly contacting the outer peripheral surface of the photoconductor drum is provided. The elastic sealing material can prevent the inward diffusion, and since the air downstream of the sealing material is not sucked, the ozone suction efficiency is further improved.

Further, if a charger is detachably attached to the apparatus main body and an ozone filter is detachably attached to the ozone recovery passage of the charger on the open side facing the photosensitive drum, the charger is detached from the apparatus main body. When the ozone filter is taken out, the ozone filter can be taken out at the same time, so that the exchangeability of the ozone filter is improved. If the direction of ventilation of the ozone filter is tilted toward the suction device, the ozone filter has an increased contact area with the air passing through it even if the thickness is the same, so the ozone decomposition efficiency is improved. However, since the ventilation direction of the filter is oriented in the direction along the flow of the air, the ventilation resistance is reduced and the air flow becomes smoother.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. 1 is a longitudinal sectional view showing a main part of an image forming apparatus equipped with an exhaust device according to an embodiment of the present invention.
Similarly, FIG. 3 is a bottom view showing the exhaust device and the charger, and FIG. 3 is a schematic configuration diagram showing the periphery of the photosensitive drum of the copying machine as the image forming apparatus.

In this copying machine, as shown in FIG. 3, the paper P fed from the paper feed cassette 2 inserted in the side surface of the main body 1 of the apparatus is exposed by the registration roller 3 after being timed. It is conveyed 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 on the surface of the photosensitive drum 4 by an optical system 6 so that a latent image is formed thereon. Are attached to form a visible image (toner image).

The toner image is transferred by the transfer charger 8 onto the paper P that has been conveyed thereto, and is conveyed by the conveyor belt 9 to a fixing unit (not shown) and then ejected outside the apparatus. Then, the toner remaining on the photoconductor drum 4 is removed by the cleaning device 11 and is collected in the toner collecting chamber. Further, in this copying machine, as shown in FIG. 1, an exhaust device 1 for decomposing ozone generated during the operation of the charger 5 into carbon dioxide gas and discharging it to the outside of the machine.
0 is provided close to the surface of the photoconductor drum 4 integrally with the charger 5.

As shown in FIG. 2, the charger 5 integrally fixes a front end block 16 and a rear end block 17, both of which are made of, for example, a resin insulating material, on both left and right ends of a casing 12, and the front end thereof is fixed. The discharge wire 14 is stretched around the centers of the block 16 and the rear end block 17 with a predetermined tension, and one end thereof is connected to an electrode (not shown).

As shown in FIG. 1, the ozone recovery passageway 25 having an open surface 25a facing the photoconductor drum 4 is located downstream of the charger 5 in the rotational direction of the photoconductor drum 4 (right side in the figure). Is formed by integrally fixing the ozone recovery duct 15 to the casing 12 of the charger 5 along the axial direction of the photoconductor drum 4 and sucking it into one end 25b of the passage as shown in FIGS. 2 and 4. A device 30 is provided.

As shown in FIG. 4, the suction device 30 includes a fan 27 which is rotated by a motor (not shown) and a duct 28 which is fixed to a rear plate 18 provided at the rear of the charger 5. A removable and replaceable ozone filter 29 is attached to the outlet part of the device, the ozone generated by the charger 5 when the fan 28 is rotated is sucked into the ozone recovery passage 25, and the ozone is discharged through the opening 19. Is discharged from the machine through the duct 27 through the ozone filter 29.

In this copying machine, when a high voltage is applied to the discharge wire 14 of the charger 5 of FIG. 1 at the start of copying, ozone is generated together with the electric charge. The ozone moves to the downstream side in the rotation direction by the rotation of the photoconductor drum 4 in the direction of the arrow A, and the fan 28 of the suction device 30 rotates at the same time when the high voltage is applied to the charger 5. ..

Therefore, the inside of the ozone recovery passage 25 becomes negative pressure by the suction device 30 which has started its operation, so that the air near the surface of the photosensitive drum 4 is sucked into the ozone recovery passage 25.

Therefore, even if ozone is generated from the discharge wire 14 of the charger 5 by applying a high voltage to the discharge wire 14, the ozone flows through the passage together with the air sucked into the ozone recovery passage 25. 2 is moved in the direction of arrow C, passes through the ozone filter 29 shown in FIG. 4 in the direction of arrow B, and is decomposed into carbon dioxide gas (Co ₂ ) and discharged to the outside of the machine.

As described above, in this embodiment, the ozone recovery passage 25 is provided downstream of the charger 5 in the rotation direction of the photosensitive drum 4.
The ozone recovery duct 15 in the casing 12 of the charger 5.
Of the photosensitive drum 4 by being fixed to the cleaning device 11 and the developing device 7 because ozone is sucked through the passage and decomposed into carbon dioxide gas and discharged to the outside of the machine. Even if the toner floating in the vicinity is sucked together with the ozone, the floating toner is discharged to the outside of the machine through the ozone recovery passage 25 without passing through the casing 12 having the discharge wire 14, and thus the floating toner. Since the discharge wire is not contaminated by the toner, uneven discharge does not occur.

FIG. 5 shows an embodiment in which the opening width of the ozone recovery passage is changed along the axial direction of the photosensitive drum, and the portions corresponding to those in FIG. 2 are designated by the same reference numerals. In this embodiment, the opening width L of the ozone recovery passage 35 facing the photosensitive drum 4 (see FIG. 1) is set to the one end portion 35.
It differs from the embodiment of FIG. 2 only in that the width is gradually increased from b to the other end 35c.

In this way, near the one end 35b near the suction device 30, ozone is sucked into the ozone recovery passage 35 from its narrow opening width L1 by a strong suction force.
Near the far end 35c, the suction force is weak, but the opening width L2 is wide, so that ozone is easily sucked into the ozone recovery passageway 35, so that ozone is uniformly and efficiently distributed over the entire length of the passageway. You will be sucked.

FIG. 6 is a vertical sectional view similar to FIG. 1, showing an embodiment in which an elastic seal material is provided on one side surface of the ozone recovery passage on the downstream side in the rotation direction of the photosensitive drum, and corresponds to FIG. The same reference numerals are given to the parts to be marked. In this embodiment, a tip portion 13a is slidably brought into contact with the outer peripheral surface 4a of the photoconductor drum 4 on one side surface 25c of the ozone recovery passage 25 on the downstream side (the right side in FIG. 6) in the rotational direction of the photoconductor drum 4. For example, an insulating elastic sealing material 13 formed of a urethane sheet is provided over the entire length in the longitudinal direction.

According to this embodiment, the diffusion of ozone generated from the charger 5 into the main body of the apparatus is suppressed by the elastic sealing material 13.
This can be prevented, and since the air on the downstream side (right side in FIG. 6) of the seal material 13 is not sucked, the ozone suction efficiency is further improved.

FIGS. 7 to 9 show an embodiment in which an ozone filter is detachably attached to the open side of the ozone recovery passageway facing the photosensitive drum, and parts corresponding to those in FIGS. 1 to 4 are the same. Is attached.

In this embodiment, the charger 5 is provided so that it can be easily attached to and detached from the apparatus body (see the apparatus body 1 in FIG. 3) by a slide rail (not shown), and the ozone recovery duct of the charger 5 is provided. The ozone recovery passage 25 formed by 15 is detachably attached by inserting the ozone filter 39 into the open side facing the photosensitive drum 4, and the ozone recovery passage 25 is formed when the charger 5 is attached to the apparatus main body. The one end 25b of the ozone recovery duct 15 is
As shown in FIG. 9, the rear side plate 18 is inserted into the opening 18a.

The fan 28 of the suction device 30 is attached to the other end of the duct 27, one end of which is fixed to the opening 18a.
Is provided. According to this embodiment, when the charger 5 is taken out from the main body of the apparatus, the ozone filter 39 is also taken out at the same time, so that the exchangeability of the ozone filter is improved.

FIG. 10 is a schematic view showing an embodiment in which the ventilation direction of the ozone filter is inclined toward the suction device. The ozone filter 49 is formed so that the direction of air that is sucked into the filter is inclined so that the outlet side 49b of the filter is closer to the suction device 30 side than the inlet side 49a.

In this way, even if the ozone filter 49 has the same thickness t as the ozone filter 39 of FIG. 9,
Since the contact area of the air passing therethrough with the filter material increases, the decomposition efficiency of ozone is improved, and the ventilation direction of the filter is oriented in the direction along the flow of the air, reducing the ventilation resistance and making it smoother. It becomes a flow of air.

[0037]

As described above, according to the present invention, the ozone generated from the charger is scattered with the cleaning device, the developing device, and the like, and is also charged with the toner floating near the surface of the photosensitive drum. Since it is sucked into the dedicated ozone recovery passage and discharged to the outside of the machine without passing through the casing, the abnormal image due to discharge unevenness caused by the floating toner adhering to the discharge wire does not occur.

Further, since the diffusion of ozone is reduced, the amount of ozone discharged to the outside of the apparatus without passing through the filter is reduced, and since only one suction device is required, the device can be manufactured at low cost.

Further, if the opening width of the ozone recovery passageway facing the photosensitive drum is gradually widened from one end where the suction device is provided to the other end, the suction force becomes weaker. Since the opening width is widened in the portion far from the above, it is possible to cover the decrease of the suction force, so that ozone is uniformly and efficiently sucked into the ozone recovery passage over the entire length thereof.

Further, if an elastic sealing material that is in sliding contact with the outer peripheral surface of the photoconductor drum is provided on one side surface of the ozone recovery passage on the downstream side in the rotation direction of the photoconductor drum, the ozone generated from the charger will be in the main body of the apparatus. To the ozone recovery passage is prevented by the elastic sealing material, and the ozone-free air downstream of the sealing material is not sucked into the ozone recovery passage. ..

Furthermore, if a charger is detachably attached to the main body of the apparatus and an ozone filter is detachably attached to the ozone recovery passage of the charger on the open side facing the photosensitive drum, the charger is removed from the main body of the apparatus. When the ozone filter is taken out, the ozone filter can be taken out at the same time, so that the exchangeability of the ozone filter is improved.

If the ventilation direction of the ozone filter is inclined toward the suction device, even if the ozone filter has the same thickness, the contact area with the air passing therethrough increases, so that ozone is decomposed. The efficiency is improved, and the ventilation direction of the filter is oriented in the direction along the air flow, so that the ventilation resistance is reduced and the air flow becomes smoother.

[Brief description of drawings]

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

FIG. 2 is a bottom view showing an exhaust device and a charger of the same.

FIG. 3 is a schematic configuration diagram showing the periphery of a photosensitive drum of a copying machine as the image forming apparatus.

FIG. 4 is a schematic view showing a cross section of a suction device provided in the exhaust device of FIG. 1 together with a part of a charger.

FIG. 5 is a bottom view similar to FIG. 2, showing another embodiment of the present invention only in the vicinity of essential parts.

FIG. 6 shows still another embodiment of the present invention.
It is a longitudinal cross-sectional view similar to FIG.

FIG. 7 is a longitudinal sectional view of an embodiment in which an ozone filter is detachably attached to the ozone recovery passage of the embodiment of FIG.

FIG. 8 is a bottom view of the same embodiment.

FIG. 9 is a sectional view showing the vicinity of the absorber of the same embodiment.

FIG. 10 is a front view showing an embodiment in which the ventilation direction of the ozone filter is inclined toward the suction device.

[Explanation of symbols]

1 Device Main Body 4 Photosensitive Drum 5 Charging Device 7 Developing Device 10 Exhaust Device 11 Cleaning Device 12 Casing 13 Elastic Sealing Material 14 Discharge Wire 25, 35 Ozone Recovery Passage 28 Fan 29, 39, 49
Ozone filter 30 Suction device

Claims (5)

[Claims] 1. An image forming apparatus in which a charger is disposed around a photosensitive drum, and ozone is recovered by opening a surface facing the photosensitive drum downstream of the charger in the rotation direction of the photosensitive drum. An image forming apparatus equipped with an exhaust device, characterized in that a passage is formed integrally with the casing of the charger along the axial direction of the photosensitive drum, and a suction device is provided at one end of the passage. 2. An image forming apparatus including the exhaust device according to claim 1, wherein an opening width of the ozone recovery passage facing the photosensitive drum is gradually widened from the one end to the other end. An image forming apparatus equipped with an exhaust device, characterized in that 3. An image forming apparatus provided with the exhaust device according to claim 1, wherein an outer peripheral surface of the photosensitive drum is slid on one side surface of the ozone recovery passage on a downstream side in the rotation direction of the photosensitive drum. An image forming apparatus provided with an exhaust device, which is provided with an elastic sealing material in contact therewith. 4. An image forming apparatus including the exhaust device according to claim 1, wherein the charger is detachably attached to an apparatus main body, and the ozone recovery passage of the charger is provided. 2. An image forming apparatus equipped with an exhaust device, wherein an ozone filter is detachably attached to the open side facing the photosensitive drum. 5. An image forming apparatus having an exhaust device according to claim 4, wherein the ozone filter has a ventilation direction inclined toward the suction device.