JPH11327264A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which prevents sticking of a silicon compound to a discharge wire constituting an electrifying device, eliminates the need of the maintenance of a discharge wire, and also increases design freedom. SOLUTION: Air lead-in fans 72 and 73 for taking outside air into the main body 36 of the image forming device are arranged on the front side of the main body 36 of the image forming device and furthermore on the front side of an image formation frame 35. Air sent out from the air lead-in fans 72 and 73 is led to the rear side of a discharge wire via ducts 77, and the air is blown toward a photoreceptor drum from the rear side of the discharge wire. Thereafter the air is discharged out of the main body 36 of the image forming device by means of an air exhaust fan 82 disposed at the rear of the main body 36 of the image forming device. As a result, a gas containing a silicon compound, around the discharge wire, is forcibly discharged by the fresh outside air toward the rear of the main body 36 of the image forming device.

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 printer, a copying machine, and a facsimile for forming an image on a transfer member such as paper or a plastic sheet.

[0002]

2. Description of the Related Art For example, a printer for forming a color image on a sheet material (transfer member) such as paper generally has a transfer drum system, an intermediate transfer system, a tandem system and a multiple development system.
Recording methods. Of these, in response to the recent demand for high-speed recording, a tandem method that is superior to other methods in recording speed has been often adopted. In the tandem type printer, black, cyan, magenta, and yellow image forming units are appropriately arranged in a sheet conveying direction, and toner images of respective colors formed by these image forming units are transferred to a sheet member. A desired color image is fixed on the sheet material by a fixing device (fixing device).

In such a color printer, a charging device constituting an image forming means is configured to charge the surface of a photoreceptor by discharging a discharge wire. In such a charging device, the amount of the silicon compound attached to the surface of the discharge wire increases as the operation time elapses.

Therefore, conventionally, the charging device has
A wire cleaning tool that slides on the discharge wire is attached, and the wire cleaning tool is manually operated to remove the silicon compound attached to the discharge wire.

[0005]

However, in the prior art as described above, the wire cleaning tool has to be attached to the charging device and the wire cleaning tool has to be manually operated as described above. Burden was heavy. In addition, since a space for manually operating the wire cleaning tool had to be secured around the charging device, the degree of freedom in designing a color printer (image forming apparatus) was small.

Accordingly, it is an object of the present invention to provide an image forming apparatus which can reduce the burden of maintenance of a charging device by a user and increase the degree of freedom in design.

[0007]

According to a first aspect of the present invention, an image forming frame for removably housing an image forming unit for visualizing an electrostatic latent image of a photosensitive member as a toner image is provided on a transfer member of the image forming apparatus main body. The image forming apparatus is configured to be able to be pulled out in a front side direction orthogonal to a transport direction. An air introduction fan for taking in outside air into the image forming apparatus main body is disposed on the front side of the image forming apparatus main body and on the front side of the image forming frame, and the air sent from the fan is discharged through a duct. After guiding the air to the back side of the wire and blowing the air from the back side of the discharge wire toward the photoreceptor, the air is discharged by an air discharge fan arranged on the back side of the image forming apparatus main body. It is characterized in that it is discharged to the outside.

According to the present invention having such a configuration, the atmosphere around the discharge wire is forcibly discharged to the outside of the image forming unit by fresh outside air, and the air discharged from the image forming unit is discharged by the discharge fan. Air is exhausted to the back side of the image forming apparatus main body. Therefore, not only can the silicon compound be effectively prevented from adhering to the discharge wire, but the exhaust gas discharged from the image forming apparatus main body is
There is no direct blow to the user at the front side of the image forming apparatus main body, and no exhaustion from the image forming apparatus main body gives the user any discomfort.

According to a second aspect of the present invention, the image forming frame detachably accommodates a plurality of color image forming units, and the air introducing fan and the air discharging fan each include at least one image forming unit.
It is characterized by being arranged more than one.

According to the present invention having such a configuration, a plurality of image forming units using toners for respective colors such as black, cyan, magenta, and yellow are accommodated, and a color image is formed by the plurality of image forming units. Also, in the image forming apparatus, the atmosphere around the discharge wires of the plurality of image forming units is forcibly exhausted to the rear side of the image forming apparatus main body by the air introduction fan and the air discharge fan. The silicon compound is prevented from adhering to the image forming apparatus, and the user located on the front side of the image forming apparatus main body is not discomforted by the exhaust from the image forming apparatus main body.

The invention according to a third aspect is characterized in that the air discharge fan is arranged at a position on the back side of the image forming apparatus main body and on the side of the fixing device.

According to the present invention having such a configuration, it is possible to create a flow of air around the fixing device which is heated to a high temperature, and to effectively cool the periphery of the fixing device.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[Image Forming Apparatus] FIG. 1 is a schematic configuration diagram of a color printer (image forming apparatus) 2 in which the fixing device of the present invention is used.

First, a schematic configuration of the color printer 2 will be described with reference to FIG. The color printer 2 includes a sheet feeding unit 4 for feeding sheet materials 3 as transfer members one by one, a conveying unit 6 for conveying the sheet material sent from the sheet feeding unit 4 to an image forming unit 5 described later, An image forming unit 5 for forming a toner image to be transferred onto the sheet material conveyed by the conveying unit 6
A transfer conveyance unit 7 that receives the sheet material conveyed by the conveyance unit 6, conveys the sheet material in a predetermined direction, and transfers the toner image formed by the image forming unit 5 to the sheet material; A fixing unit 8 for fixing the toner image on the sheet material conveyed by the transfer conveyance unit 7 to the sheet material;
The image forming unit 5 includes a paper discharge unit 10 that receives the sheet material discharged from the fixing unit 8 and an optical unit 11 that irradiates the image forming unit 5 with laser light for exposure.

The sheet feeding section 4 feeds the sheet material 3 stacked on the first sheet feeding tray 12 to the sheet feeding roller 13 and the reverse roller 1.
4 and a second paper feed unit 18 that feeds a sheet material (not shown) on the manual feed tray 16 by a paper feed roller 17.

The transport section 6 includes a transport path 20 for guiding the movement of the sheet material 3 sent from the first paper feed section 15, a transport roller 21 disposed in the middle of the transport path 20, and a transport roller 21. The registration roller pair 22 receives the sheet material from the printer, corrects the skew of the sheet material, and sends the sheet material to the image forming unit 5.
And a manual feed path 23 that is connected to the feed path 20 upstream of the registration roller pair 22 in the sheet feed direction.

The image forming section 5 includes a first image forming section 24 having black toner (hereinafter abbreviated as black) and a toner containing cyan pigment (hereinafter abbreviated as cyan) in order from the upstream side in the sheet conveying direction. , A third image forming unit 26 having a magenta pigment-containing toner (hereinafter, abbreviated as magenta), and a fourth image having a yellow pigment-containing toner (hereinafter, abbreviated as yellow). Part 27
It consists of Each of the first to fourth image forming units (image forming units) 24 to 27 has a cylindrical photoconductor drum (photoconductor) 28 and a developing device that forms a toner image on the outer peripheral surface of the photoconductor drum 28. A cleaning device 33 including a device 30; a fur brush 31 for removing residual toner on the photosensitive drum 28; and a cleaning blade 32; and a charging device 34 for applying a charge to the photosensitive drum 28 to charge the photosensitive drum 28. And
Note that the image forming unit 5 can be pulled out of the image forming apparatus main body 36 integrally with the image forming frame 35.

The transfer / conveying section (transfer means) 7 includes an endless transfer belt 37 made of a fluororesin material and the transfer belt 3.
Roller 38 and Tension Roller 40 for Wrapping 7
And transfer rollers 41a, 41b, 41c, 41d arranged at positions facing the respective photosensitive drums 28, respectively. Then, these transfer rollers 41a to 41d
The transfer belt 37 is interposed between the transfer belt 37 and the photosensitive drum 28. Further, belt guide rollers 42 and 43 are disposed at appropriate positions on the inner peripheral side of the transfer belt 37. The transfer conveyance section 7 includes a photosensitive drum 28, a transfer roller 41
In order to prevent the deterioration of the transfer belt 37a and the transfer belt 37, the print roller is lowered to the position indicated by the two-dot chain line when printing is stopped, and the tension roller 40 is slightly moved to the drive roller 38 side. The pressure acting on the transfer belt 37 and the tension acting on the transfer belt 37 are released. In addition, the transfer conveyance section 7
Is provided with a mechanism (not shown) for separating the other cyan, magenta, and yellow transfer rollers 41b to 41d from the photosensitive drum 28 when only a monochrome image is created. Here, the drive roller 38 is connected to a drive motor (not shown) via a torque limiter (not shown).
When a torque equal to or more than a predetermined value acts, a slip occurs on the drive motor. Accordingly, the transfer belt 37 is given a driving force by the driving roller 38, but follows the rotation of the photosensitive drum 28.

The fixing section (fixing device) 8 includes a heating roller 44 having a built-in heater, a fixing roller 45, an endless metal belt 46 wound around the heating roller 44 and the fixing roller 45, a fixing roller And a pressing roller 47 pressed against the pressing roller 45. And the endless belt 46
A donor roller (release agent application roller) 48 for applying a silicone oil as a release agent to the outer surface of the roller, an oil roller (supply roller) 50 that rolls into contact with the donor roller 48 and supplies the release agent, A cleaning roller 51 for rolling and contacting the donor roller 48 to clean the surface of the donor roller 48 is provided.

The paper discharge section 10 guides the sheet material discharged from the fixing section 8 to the upper portion of the image forming apparatus main body 36 via a discharge path 53, and the paper discharge tray 54 for stacking the image material on the image forming surface.
have. The paper ejection cover 52 can be pulled out of the image forming apparatus main body 36 when the jam is cleared, and can be stored in the image forming apparatus main body 36 when the jam is not cleared.

The optical unit 11 has an exposure device 11a, 11b, 11c, 11d having a polygon scanner mirror 55, image forming lenses 56, 57 and a mirror 58, and is arranged corresponding to each photosensitive drum 28. Slit 6 formed in optical unit frame 60
Irradiation is performed from 1a, 61b, 61c, 61d toward the photosensitive drum 28.

The color printer 2 configured as described above
When a sheet material is sent out from the first paper supply unit 15 or the second paper supply unit 18, the sheet material is sent to the first
It is fed between the photosensitive drum 28 of the image forming unit 24 and the transfer belt 37 of the transfer / conveyance unit 7. And the sheet material is
While being conveyed by the transfer belt 37 between the photosensitive drum 28 and the transfer rollers 41a to 41d, black, cyan,
The toner images formed on the magenta and yellow photosensitive drums 28 are sequentially transferred. Then, the sheet material on which the transfer of the color image has been completed is sent by the transfer belt 37 between the fixing roller 45 and the pressing roller 47 of the fixing unit 8, where the sheet material is heated and pressed to fix the color toner image. You. The sheet material on which the fixing operation has been completed is discharged to the discharge tray 54.

Next, the flow of air in the image forming apparatus main body 36 will be described with reference to FIGS. FIG.
5 is a plan view showing the flow of air in the image forming apparatus main body 36. FIG. FIG. 3 shows a cross section of the image forming units 24 to 27 on the side of the charging device 70 and the cleaning device 71.

As shown in these drawings, on the front side of the image forming apparatus main body 36 and on the front side of the image forming frame 35, a first air introducing fan 72 for taking in outside air into the image forming apparatus main body 36 and a second air introducing fan 72 are provided. Two air introduction fans 73 are arranged in a pair. The first image forming unit 24 is provided in the air introduction chamber 74 in which the first air introduction fan 72 is disposed.
And the discharge wire 7 of the charging device 70 of the second image forming unit 25
6 Duct 77 attached to the back side (upper side in FIG. 3)
Are communicated via a branch passage 78, and the air sent from the first air introduction fan 72 is introduced into the back side of each of the discharge wires 76, 76 of the first image forming unit 24 and the second image forming unit 25. It is supposed to be. Note that the duct 77 is disposed in the direction in which the discharge wires 76 are disposed (the direction orthogonal to the transfer body transport direction).
Is attached along. Also, the image forming frame 35
Can be pulled out in a direction perpendicular to the transfer body transport direction, that is, in a front side direction of the image forming apparatus main body 36.

A third image forming section 26 and a fourth image forming section 27 are provided in the air introducing chamber 75 in which the second air introducing fan 73 is disposed.
A duct 77 attached to the back side of the discharge wire 76 of the charging device 70 is communicated via a branch path 78, and the air sent from the second air introduction fan 73 is supplied to the third image forming unit 26 and the fourth Each discharge wire 7 of the image forming unit 27
6, 76 on the back side.

An outlet 80 for generating an airflow that passes through the discharge wire 76 and travels toward the photosensitive drum 28 is provided in the duct 77 attached to each of the image forming units 24 to 27.
Are formed. Therefore, the air taken in from the first air introduction fan 72 is supplied to the branch passage 78 and the duct 7.
The discharge wire 76 is blown toward the surface of the photoreceptor drum 28 from the back side of the discharge wire 76. As a result, a gas containing a silicon compound or ozone existing around the discharge wire 76 is forcibly discharged from the charging device 70 into the space in the image forming apparatus main body 36, and the silicon compound adheres to the discharge wire 76. It can be effectively prevented. Therefore, the user does not need to clean the discharge wire 76.

The gas discharged from the charging device 70 is
The fixing device 8 flows through the space 81 in the image forming apparatus main body 36 and is located on the rear side (back side) of the image forming apparatus main body 36 and the fixing device 8 (FIG. 1).
See) Air exhaust fan 82 attached to a nearby site
As a result, the toner is discharged to the external space on the rear side of the image forming apparatus main body 36. As described above, since the air taken into the image forming apparatus main body 36 passes through the space on the fixing device 8 side,
The components, frame, and the like around the fixing device 8 can be cooled. Further, since air is taken in from the front side of the image forming apparatus main body 36 and exhausted to the rear side of the image forming apparatus main body 36, a gas containing a silicon compound or ozone is directly blown to the user. No discomfort to the user.

As described above, in the present embodiment, the outside air taken in by the air introduction fans 72 and 73 is charged by the charging device 70.
Is discharged from the back side of the discharge wire 76 toward the surface of the photoreceptor drum 28 to forcibly discharge a gas containing a silicon compound and ozone around the discharge wire 76 from the charging device 70. The silicon compound can be effectively prevented from adhering to the wire 76, and maintenance by a user is not required. In addition, a wire cleaning tool for the discharge wire, which is installed in the conventional image forming apparatus, is not required, and a space for operating the wire cleaning tool is not required, so that the degree of freedom in designing the image forming apparatus is increased. In addition, according to the present embodiment, a silicon compound can be effectively prevented from adhering to the discharge wire 76, so that a good image without discharge unevenness can be formed.

In this embodiment, the image forming apparatus main body 3
6 from the front side of the image forming apparatus main body 3
Since the exhaust gas is discharged to the rear side of 6, the gas containing ozone and silicon compound is not directly blown to the user, and the user is not uncomfortable.

Further, in this embodiment, the air discharge fan 8
2 is disposed on the rear side of the image forming apparatus main body 36 and at a position beyond the fixing device 8, so that the image forming apparatus main body 36
The flow of the air flowing through the space is guided to the fixing device 8 side, and the components and the like heated by the fixing device 8 can be cooled.

Although the image forming apparatus according to the above embodiment has been described as applied to a color printer, it is not limited to this, and can be widely applied to facsimile machines, copiers, and the like.

In the above embodiment, the plurality of image forming units from the first image forming unit 24 to the fourth image forming unit 27 are
Although the explanation has been given taking the example of attaching to 5, the present invention is not limited to this.
The present invention is also applicable to a case where a single imaging unit is mounted on an imaging frame. That is, the present invention can be applied to an image forming apparatus that prints only a black and white image.

Further, in the above-described embodiment, a configuration in which the air introducing fans 72 and 73 are arranged in a pair has been described. However, air may be introduced into the image forming apparatus main body 36 by a single air introducing fan. Alternatively, three or more air introduction fans may be arranged.

In addition, in the above-described embodiment, the mode in which the single air exhaust fan 82 is disposed on the rear side of the image forming apparatus main body 36 and on the side of the fixing device 8 has been described. A plurality of devices may be arranged at appropriate positions on the rear side of the device main body 36.

[0036]

As is apparent from the above description, according to the first aspect of the present invention, outside air is taken into the image forming apparatus main body at the front side of the image forming apparatus main body and at the front side of the image forming frame. An air introduction fan is arranged, the air sent from the fan is guided to the back side of the discharge wire via a duct, and the air is blown from the back side of the discharge wire toward the photoconductor, and then the air is used in an image forming apparatus. Since the air is discharged to the outside of the image forming apparatus main body by an air discharge fan arranged on the rear side of the main body, the atmosphere around the discharge wire is forcibly discharged to the outside of the image forming unit by fresh outside air, In addition, the air exhausted from the image forming unit is exhausted to the rear side of the image forming apparatus main body by the air exhaust fan. Thus, according to the present invention,
It is possible to effectively prevent the silicon compound from adhering to the discharge wire, and it is possible to form a good image without charging unevenness, as well as to eliminate the need for user maintenance and to reduce the user's burden of maintenance. or,
According to the present invention, since the maintenance of the user is not required, the wire cleaning tool used in the conventional example is not required, and it is not necessary to secure a space for operating the wire cleaning tool. Design flexibility is increased. Further, according to the present invention, the exhaust air discharged from the image forming apparatus main body does not directly blow to the user at the front side of the image forming apparatus main body, and the exhaust from the image forming apparatus main body does not impair the user. No pleasure.

According to the second aspect of the present invention, the image forming frame detachably houses a plurality of color image forming units, and at least one air introducing fan and one air discharging fan are provided.
Or more, and the atmosphere around the discharge wires of the plurality of image forming units is forcibly exhausted to the rear side of the image forming apparatus main body by an air introduction fan and an air discharge fan. The compound can be prevented from adhering, and the maintenance of the discharge wire by the user can be eliminated. Therefore, according to the present invention, the effect of reducing the maintenance burden on the discharge wire of the user is increased by the configuration in which the plurality of image forming units are accommodated.

Further, according to the third aspect of the present invention, since the air discharge fan is disposed at the position on the back side of the image forming apparatus main body and on the side of the fixing apparatus, the air discharging fan is heated to a high temperature. An air flow can be created around the periphery, and the periphery of the fixing device can be effectively cooled.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a flow of air inside the image forming apparatus.

FIG. 3 is a sectional view of a main part of the image forming unit according to the embodiment of the present invention.

[Explanation of symbols]

2 ... color printer (image forming apparatus), 8 ... fixing device, 24 to 27 ... first to fourth image forming units (image forming units), 28 ... photosensitive drums (photosensitive bodies), 35 ... Image forming frame 36, image forming apparatus main body 72, 73
Air introduction fan, 76 discharge wire, 77 duct, 82 air discharge fan

Claims (3)

[Claims] An image forming frame for detachably housing an image forming unit for visualizing an electrostatic latent image of a photoreceptor as a toner image can be pulled out in a front side direction orthogonal to a transfer body conveying direction of an image forming apparatus main body. An air introduction fan that takes in outside air into the image forming apparatus main body is disposed on the front side of the image forming apparatus main body and on the front side of the image forming frame. The delivered air was guided to the back side of the discharge wire through the duct, and the air was blown from the back side of the discharge wire toward the photoconductor, and then the air was disposed on the back side of the image forming apparatus main body. An image forming apparatus, wherein the air is discharged to the outside of the image forming apparatus main body by an air discharge fan. 2. The image forming frame according to claim 1, wherein a plurality of color image forming units are detachably accommodated, and at least one of the air introduction fan and the air discharge fan is arranged. The image forming apparatus as described in the above. 3. The image forming apparatus according to claim 1, wherein the air discharge fan is disposed at a position on a back side of the image forming apparatus main body and on a side of the fixing device.