JPH08123265A - Exhauster for image forming device - Google Patents

Abstract

PURPOSE: To efficiently remove ozone generated from an electrostatic charging corotron without separately incorporating an ozone discharging duct and an ozone discharging fan at the inside of the exhaust flow path of the image forming device. CONSTITUTION: An ozone filter 21 is arranged in the midway of the exhaust flow path 23 communicating with the inside of the image forming device 1, and the air in the image forming device 1 is sucked by a fan 22 installed on the downstream side away from the ozon filter 21, then, the air is discharged outside the image forming device 1. The upstream side of the ozone filter 21 in the exhaust flow path 23 is divided by a partition board 24 into a 1st flow path communicating between the ozone filter 21 and the electrostatic charging corotron 5 and a 2nd flow path communicating between the ozone filter 21 and the inner part of the image forming device 1 other than the electrostatic charging corotron 5, and as for the 1st flow path, the opening area facing to the ozone filter 21 is made larger than the opening area facing to the electrostatic charging corotron 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for removing ozone, dust, toner, paper dust, etc. generated inside an image forming apparatus such as an electrophotographic copying machine or a laser printer from the inside of the image forming apparatus. The present invention relates to an exhaust device, and more particularly, to an exhaust device for efficiently removing ozone generated in a charging corotron inside an image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine or a laser printer, ozone or paper dust is generated in the image forming process, toner is scattered, and dust or dirt enters from the outside of the apparatus. Is stagnation around the charged corotron. On the other hand, the air inside the image forming apparatus is exhausted to the outside of the apparatus by the cooling fan through the exhaust flow passage, but the air flow from each part inside the apparatus is directed to the cooling fan. It was difficult to obtain enough air volume to remove by suction. As a result, ozone, paper dust, toner, dust, etc. remain in the vicinity of the charging corotron and are not discharged to the outside of the device and adhere to the charging corotron wire, so that the charging effect on the surface of the photoconductor drum is impaired. There is an inconvenience that the image becomes stable and a high quality image cannot be obtained.

Therefore, in the prior art, Japanese Patent Laid-Open No. 63-27148
As disclosed in Japanese Patent Laid-Open No. 2 (1993), in order to remove ozone, toner, paper powder, dust, etc. that have stagnated around the charging corotron, an exhaust flow passage for exhausting the air inside the image forming apparatus to the outside of the apparatus, A stagnation suction fan was provided separately from the cooling fan. FIG. 3 shows the above-mentioned Japanese Patent Laid-Open No. 63-271482
FIG. 3 is a cross-sectional view showing an outline of the structure of the exhaust device shown in Japanese Patent Publication.

In FIG. 1, around the photosensitive drum 4 provided inside the image forming apparatus 1, a charging corotron 5, a developing device 6, and a developing device 6 are arranged in order along the rotation direction of the photosensitive drum 4 indicated by an arrow A. A transfer corotron 7 and a cleaner 8 are arranged.

An exhaust device 20 having an exhaust flow passage 23 communicating with the outside of the image forming apparatus through an ozone filter or a dust filter (not shown) is provided above the photosensitive drum 4. In addition, an ozone discharge duct 30 is arranged inside the exhaust flow passage 23 so as to surround the charging corotron 5, and the ozone generated in the charging corotron 5 is sucked into the ozone discharge duct 30. An ozone discharge fan 31 for sending the exhaust gas toward the outlet side of the exhaust flow passage 23 is provided.

In the above structure, the surface of the photosensitive drum 4 rotating in the direction of arrow A is charged when passing through the charging corotron 5, and the charged portion is scanned by an image writing device (not shown). Beam developing device 6
A latent image is formed while moving to.

Then, in the developing device 6, toner is attached to the latent image, a toner image is formed and the toner image is moved to the position of the transfer corotron, where it is supplied between the photosensitive drum 4 and the transfer corotron 7. The toner image on the photosensitive drum 4 is transferred onto the sheet to be printed.

The sheet on which the image is transferred is further discharged to the outside of the image forming apparatus 1 via a fixing device (not shown). On the other hand, the photosensitive drum 4 rotates in the direction of arrow A from the position of the transfer corotron 7 to reach the cleaner 8, where the toner left on the surface without being transferred onto the paper is removed.

During operation of the above image forming apparatus, the ozone discharge fan 31 in the ozone discharge duct 30 is rotationally driven to suck the ozone generated by the discharge of the charging corotron 5, and to discharge the ozone in the exhaust flow passage 23. Send it to the exit side. On the other hand, the air inside the image forming apparatus 1 other than the charging corotron 5 is discharged from the exhaust flow passage 23 to the outside by suction of a cooling fan (not shown) arranged on the outlet side.

[0010]

However, in the exhaust device having the structure disclosed in Japanese Patent Laid-Open No. 63-271482, ozone is discharged further inside the exhaust flow passage arranged in the image forming apparatus. Since the ozone discharge duct with the built-in fan is incorporated, there is a problem that the structure becomes complicated and the manufacturing cost becomes high. In addition, the image forming apparatus becomes large in size, which causes a problem that it cannot cope with the recent space saving of the office.

[0011]

It is an object of the present invention to solve the above problems and to generate from a charging corotron without separately incorporating a duct for discharging ozone or a fan for discharging ozone inside the exhaust flow passage. An object of the present invention is to provide an exhaust device for an image forming apparatus, which is capable of efficiently removing ozone.

[0012]

To achieve the above object, in the exhaust device of the image forming apparatus of the present invention, an ozone filter is arranged in the middle of an exhaust flow passage communicating with the inside of the image forming apparatus,
In the exhaust device of the image forming apparatus, the air inside the image forming apparatus is sucked by a fan provided on the downstream side of the ozone filter and discharged to the outside of the image forming apparatus. The upstream side is partitioned by a partition plate, and a first flow passage communicating between the ozone filter and a charging corotron provided inside the image forming apparatus, and an image formation other than the ozone filter and the charging corotron. A second flow passage communicating with a portion inside the apparatus, and an opening area of the first flow passage facing the ozone filter is formed larger than an opening area facing the charging corotron. It is characterized by being present.

A dust filter is preferably added to the air inflow side of the ozone filter.

[0014]

In the exhaust system of the present invention, the upstream side of the ozone filter disposed in the exhaust flow passage is divided into the first flow passage and the second flow passage by the partition plate. The flow passage is opened facing the charging corotron. When the fan on the downstream side of the exhaust flow passage is driven, the air around the charging corotron is sucked from the opening of the first flow passage facing the charging corotron and moves toward the ozone filter side. On the other hand, the second flow passage communicates with each part inside the image forming apparatus other than the charging corotron, and sucks and exhausts the air in each part.

Since the opening area of the first flow passage that faces the ozone filter is larger than the opening area that faces the charging corotron, the opening side of the first flow passage that faces the charging corotron. The flow velocity of the air sucked from is high.

As a result, the ratio of the amount of air sucked from the charging corotron to the total amount of air sucked from the exhaust flow passage by the fan becomes large, and stagnant suspended matter such as ozone and toner around the charging corotron is efficiently removed. To be done.

Further, by adding the dust filter to the air inflow side of the ozone filter, deterioration of the function due to clogging of the ozone filter can be suppressed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an electrophotographic copying machine as an image forming apparatus to which the exhaust device of the present invention is applied. On the upper surface of the image forming apparatus 1, a platen for placing a document is placed. Two are provided. A scanning device 3 is arranged on the lower surface of the platen 2 so as to be horizontally movable inside the image forming apparatus 1. The scanning device 3 scans the surface of the original by irradiating the original S on the platen 2 with the light S, and reflects the reflected light through the optical system such as a reflecting mirror and a lens onto the surface of the photoconductor drum 4 arranged below. Irradiate. The photoconductor drum 4 is configured to be rotationally driven with the movement of the scanning device 3, and the charging corotron 5 is arranged around the photoconductor drum 4 in order along the rotation direction of the photoconductor drum 4 indicated by an arrow A. A developing device 6, a transfer corotron 7, and a cleaner 8 are arranged.

On the other hand, a paper feed tray 9 is detachably provided at the bottom of the image forming apparatus 1, and a large number of papers P are accommodated therein. At a position facing the upper surface of the paper feed tray 9 on the paper take-out side, a paper feed roller 10 for sequentially feeding the paper P in the paper feed tray 9 is arranged. The paper P delivered from the paper feed tray 9 by the paper feed roller 10 is configured to be guided between the photoconductor drum 4 and the transfer corotron 7 by a guide means such as a plurality of guide rollers and guide members. There is.

The belt conveying device 11 guides the paper P passing between the photosensitive drum 4 and the transfer corotron 7,
It is provided for feeding to the fixing device 12. A discharge roller 13 is provided on the downstream side of the fixing device 12, and the image forming apparatus 1 is located at a position facing the discharge side of the discharge roller 13.
A discharge tray 14 is attached to the side surface of the.

Next, provided in the image forming apparatus 1,
Explaining the exhaust device 20, the exhaust device 20 has an exhaust flow passage 23 provided below the space inside the image forming apparatus 1 in which the scanning device 3 is housed and opened to the outside of the image forming apparatus 1. ing.

The ozone filter 21 is arranged in the middle of the exhaust flow passage 23, and the ozone filter 21 is disposed inside the image forming apparatus 1 on the downstream side, that is, on the outlet side of the exhaust flow passage 23 to the outside of the image forming apparatus 1. A fan 22 is arranged for sucking air and discharging the air to the outside of the apparatus. The exhaust flow passage 23 is
The upstream side of the ozone filter 21 is divided into two passages by a partition plate 24.

FIG. 2 is an enlarged sectional view showing a peripheral portion of the partition plate 24 shown in FIG. 1. The exhaust flow passage 23 is divided into the first flow passage 23A and the second flow passage 23A by the partition plate 24. The flow passage 23B is divided into two flow passages. Of the two flow passages, the first flow passage 23A has an upstream end facing the charging corotron 5 and opening. On the other hand, the downstream end of the first flow passage 23A is opened so as to face the ozone filter 21. The vertical distance H1 of the opening at the downstream end of the first flow passage 23A is larger than the vertical distance H2 of the opening at the upstream end. That is, the first flow passage 23A is formed so that the opening area facing the ozone filter 21 is larger than the opening area facing the charging corotron 5.

On the other hand, the second flow passage 23B has a partition plate 24.
The lower part of the image forming device is open and communicates with each part inside the image forming apparatus 1. The ratio of the air volume sucked from the first flow passage 23A and the air volume sucked from the second flow passage 23B is determined by the position of the partition plate 24 facing the ozone filter 21. The position of the partition plate 24 with respect to the ozone filter 21 is set so that a sufficient air volume for sucking and removing suspended matters such as ozone and toner from around the charging corotron 5 can be obtained in the first flow passage 23A.

Next, the operation of the exhaust device 20 having the above structure will be described together with the operation of the image forming apparatus 1. When the power of the image forming apparatus 1 shown in FIG. 1 is turned on, the motor of the fan 22 arranged on the downstream side of the exhaust flow passage 23 of the exhaust device 20 is driven, and the fan 22 starts rotating. And
When a document to be copied is placed on the platen 2 and a copy operation is performed using an operation panel (not shown) arranged outside the image forming apparatus 1, the scanning device 3 below the platen 2 is moved to the surface of the document via the platen 2. Scanning is performed by applying light S. The light S reflected by the surface of the original enters the platen 2 again,
The light is deflected through the scanning device 3 and the optical system fixedly arranged inside the image forming apparatus 1, and the surface of the photosensitive drum 4 is irradiated with the light.

The surface of the photosensitive drum 4 at the position of the charging corotron 5 is charged by the discharging of the charging corotron 5. The photosensitive drum 4 is rotationally driven in the direction of arrow A, and when it reaches a position where the light from the scanning device 3 is irradiated, a latent image is written on the surface of the photosensitive drum 4 here. When the photoconductor drum 4 continues to rotate in the direction A, the position where the latent image is recorded on the surface of the photoconductor drum 4 comes to the position of the developing device 6, and at this position toner is discharged from the developing device 6 to the photoconductor drum 4. A toner image is formed by being attached to the latent image on the surface. The position where the toner image is formed on the surface of the photoconductor drum 4 moves to the position where the transfer corotron 7 is provided by the rotation of the photoconductor drum 4.

The paper P accumulated and stored in the paper feed tray 9 is positioned at the uppermost position from the paper feed tray 9 by the rotation of the paper feed roller 10 at the same timing as the rotation of the photosensitive drum 4. The sheet is taken out and supplied to the gap between the photoconductor drum 4 and the transfer corotron 7 by the guide means including a plurality of guide rollers and guide members. Then, when the paper P passes through the gap in synchronization with the rotation of the photoconductor drum 4, the toner image on the photoconductor drum 4 is transferred to the paper P by the action of the transfer corotron 7.
Is transferred to The sheet P on which the image is transferred is further conveyed by the belt conveying device 11 and passes through the fixing device 12, where the image on the sheet P is fixed, and then the sheet P is discharged to the discharge tray 14 by the discharge roller 13. Is discharged.

On the other hand, the surface of the photosensitive drum 4 on which the toner image is transferred to the paper P reaches the position of the cleaner 8 by the rotation of the photosensitive drum 4, and the toner left on the surface of the photosensitive drum 4 is removed here. To be done.

In the course of the copying operation as described above, ozone is generated around the charging corotron 5 due to discharge, and fine toner powder is scattered around the photosensitive drum 4. Further, in the conveyance path of the paper P from the paper feed tray 9 to the discharge tray 14, fine paper dust is generated from the paper P along with the conveyance operation. Further, fine dust and dirt constantly enter the inside of the image forming apparatus 1 from the outside.

On the other hand, due to the rotation of the fan 22, an air flow toward the outside is always generated in the exhaust flow passage 23. Then, the air flow is divided by the partition plate 24 on the upstream side of the ozone filter 21 into a flow passing through the first flow passage 23A and the second flow passage 23B. Of these, the first
The air flow passing through the flow passage 23A of
Since the opening area of the first flow passage 23A on the side facing the charging area is smaller than the opening area on the ozone filter 21 side, the velocity of the air flow is high on the opening side facing the charging corotron 5. . Therefore, the charging corotron 5
Ozone generated around the is immediately captured by the high-speed airflow flowing into the first flow passage 23A that is open facing the charging corotron 5, and passes through the first flow passage 23A to the ozone filter 21. Carried. Then, the clean air from which ozone has been removed is discharged to the outside of the image forming apparatus 1 through the exhaust flow passage 23.

On the other hand, the air existing around the photosensitive drum 4 and in the conveying path of the paper P becomes an air flow moving toward the ozone filter 21 by the suction of the fan 22.
The air flow passes through the second flow passage defined by the partition plate 24 and flows into the ozone filter 21. The airflow includes toner and paper dust scattered inside the image forming apparatus 1 or dust and dirt that has entered from the outside and is removed from the inside of the image forming apparatus 1 together with the airflow.

In the above embodiment, the case where only the ozone filter 21 is used in order to simplify the structure of the exhaust device 20 and suppress the manufacturing cost, etc., but a dust filter may be used together with the ozone filter 21. Good. When the dust filter is used, it is preferable to add the ozone filter 21 so as to overlap the air inflow side. By using the dust filter, the ozone filter 21 is prevented from being clogged with toner, paper powder, dust, or the like discharged from the inside of the image forming apparatus 1, and the function of removing ozone is maintained for a long time. It becomes possible.

[0033]

As described above, according to the present invention,
A first flow passage, which is defined by a partition plate on the upstream side of the ozone filter in the exhaust flow passage, connects the ozone filter and a charging corotron provided inside the image forming apparatus, the ozone filter and the charging corotron. And a second flow passage that communicates with other parts inside the image forming apparatus, and the opening area of the first flow passage that faces the ozone filter is smaller than the opening area that faces the charging corotron. Since it is also formed large, the following effects can be obtained.

That is, according to the present invention, since the ratio of the air volume sucked from the charging corotron to the total air volume sucked from the exhaust flow passage by the fan can be increased, the ozone generated around the charging corotron is increased. It is possible to efficiently remove floating substances such as toner and toner. Therefore, the adherence of floating matters to the charging corotron wire is avoided, and the charging action of the charging corotron on the surface of the photosensitive drum is stabilized, so that a high quality image can be obtained. In addition, conventionally, the ozone discharge duct and the ozone discharge fan, which are provided inside the image forming apparatus to remove the ozone floating around the charging corotron and the toner, are not required. Can be simplified. As a result, the image forming apparatus can be downsized in response to space saving in offices and the like, and the number of parts constituting the image forming apparatus is reduced, so that the image forming apparatus can be easily manufactured. The manufacturing cost can be reduced.

Furthermore, by adding a dust filter to the air inflow side of the ozone filter, clogging of the ozone filter due to toner, dust, etc. can be prevented, the function of the ozone filter can be maintained for a long period of time, and maintenance is easy. Becomes

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming apparatus to which an exhaust device of the present invention is applied.

FIG. 2 is an enlarged cross-sectional view of a main part of the exhaust device of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional exhaust device.

[Explanation of symbols]

1 image forming device, 2 platen, 3 scanning device, 4 photoconductor drum, 5 charging corotron,
6 developing device, 7 transfer corotron, 8 cleaner, 9 paper feed tray, 10 paper feed roller, 11
Belt transport device, 12 fixing device, 13 discharge roller, 14 discharge tray, 20 exhaust device, 2
1 Ozone filter, 22 Fan, 23
Exhaust flow passage, 23A first flow passage, 23B second flow passage, 24 partition plate.

Claims (2)

[Claims] 1. An ozone filter is arranged in the middle of an exhaust flow passage communicating with the inside of the image forming apparatus, and the air inside the image forming apparatus is sucked by a fan provided on the downstream side of the ozone filter, In an exhaust device of an image forming apparatus configured to discharge to the outside of the image forming apparatus, an upstream side of the ozone filter in the exhaust flow passage is partitioned by a partition plate, and the charging provided inside the ozone filter and the image forming apparatus is performed. It is divided into a first flow passage that communicates with the corotron and a second flow passage that communicates between the ozone filter and a portion inside the image forming apparatus other than the charging corotron. The exhaust area of the image forming apparatus is characterized in that the opening area of the path facing the ozone filter is formed larger than the opening area facing the charging corotron. Location. 2. The air inflow side of the ozone filter,
The exhaust device for an image forming apparatus according to claim 1, further comprising a dust filter.