JPH11296053A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image forming device constituted so that the inside of a machine can be cooled without unnecessarily increasing the cost. SOLUTION: This image forming device is equipped with an image forming device main body 1 provided with an image forming part 5 forming a desired image on a paper P by developer and a fixing part 5 fixing the image on the paper P by heating and a both-surface unit 2 provided with an inversion path 25 for carrying the paper P to the main body 1 so that the image is formed even on the rear surface of the paper P by inverting the paper P obtained by fixing the image at one surface and removably fitted to the main body 1. Then, the unit 2 is provided with a fan 29 cooling the inside of the unit 2 and circulating air for cooling in the inside of the main body 1. Thus, the image forming device can be equipped with the unit 2 and the inside of the main body 1 can be cooled according to the need of a user.

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 an electrophotographic apparatus or a laser printer capable of forming an image on both sides of a transfer material.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic apparatus or a laser printer, an image forming apparatus capable of forming an image on both sides of a transfer material as well as on one side thereof is widely used. In such an image forming apparatus, the transfer material on which an image is formed on one side in the image forming unit is guided to a reversing conveyance path to reverse the transfer material. Also form an image. Such a reversing mechanism is not required for all the image forming apparatuses, and is not necessary depending on the use form of the user. Therefore, a switching claw is provided in the discharge conveyance path of the transfer material having an image formed on one side in the image forming unit, and the transfer material conveyed by switching the switching claw is inverted and sent out to the image forming unit again. It has been proposed that a duplex unit having a reversing conveyance path is detachably provided on a side of an image forming apparatus main body. Thus, when it is not necessary to form an image on both sides, it is possible to provide an image forming apparatus in which the double-sided unit is omitted and the switching claw is fixed.

In an image forming apparatus employing an electrophotographic process, an image is formed on a transfer material by forming an electrostatic latent image of an original image on a photosensitive member, developing the formed electrostatic latent image with toner,
The fixing is performed by fixing the toner image on the transfer material by heating and pressing. Since it is necessary to heat the toner image at a high temperature when fixing the toner image, the transfer material immediately after the fixing is in a heated state. When forming an image on both sides, the transfer material with the image formed on one side is conveyed to the image forming unit while maintaining the heat for fixing, so the temperature inside the machine increases compared to the image formation on only one side. Is remarkable. When the temperature inside the apparatus rises in this way, problems such as abnormal images may occur. Therefore, it has been proposed to provide a cooling fan inside the main body. However, when a double-sided unit is not provided, the cooling fan is not required because the temperature rise is not remarkable as in the case of double-sided copying. Therefore, providing a cooling fan to a model without such a double-sided unit means unnecessary cost increase for the user.

On the other hand, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-239647, it has been proposed to provide a fan in a double-sided unit so as to cool a transfer material passing through a reversing path. Since only cooling of the unit or cooling of the transfer material in the unit is required, it is possible to prevent at least unnecessary cost increase of the main body.

[0005]

However, in the above-mentioned conventional example, the fan is used only for cooling the transfer material in the duplex unit. Problems remained.

The present invention has been made in view of such a situation of the related art, and an object of the present invention is to provide an image forming apparatus capable of cooling the inside of an apparatus without unnecessary cost increase.

[0007]

In order to achieve the above object, a first means is to provide an image forming apparatus main body having respective process elements for forming an image by an electrophotographic process, and an image forming apparatus main body. A double-sided unit that is detachably provided, the transfer material is carried in from the image forming apparatus main body, and the carried-in transfer material is inverted in a reversing path defined by a guide member and is carried out to the image forming apparatus main body. In the image forming apparatus, the double-sided unit is provided with a fan for cooling the inside of the double-sided unit and flowing cooling air to the inside of the image forming apparatus main body.

A second means according to the first means, wherein a radiation fin is provided on the side of the guide member opposite to the transfer material conveying surface, and the fan supplies air into the main body of the image forming apparatus through the back surface of the guide plate. It is characterized by care.

A third means is that in the first means, the fan is disposed in the double-sided unit so as to face the image forming apparatus main body with the reverse conveyance path interposed therebetween. I do.

According to a fourth aspect, in the first aspect, the fan is provided so as to guide air above the fixing portion to the outside of the apparatus.

A fifth means is that, in the first to fourth means, cooling air is circulated inside the double-sided unit and inside the image forming apparatus main body at a position exposed outside the apparatus outside the double-sided unit. The opening is provided.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same reference numbers are given to the units that can be regarded as equivalent, and duplicate descriptions will be omitted as appropriate.

First, a first embodiment shown in FIG. 1 will be described. FIG. 1 is a configuration diagram for explaining the overall configuration of an image forming apparatus according to an embodiment of the present invention.

Reference numeral 1 denotes a main body of the image forming apparatus (hereinafter, referred to as "apparatus main body"), and a double-sided unit 2 is attached to a side portion thereof. A four-stage paper feed cassette 3 is provided on the lower side of the apparatus main body 1. These paper cassettes 3
A registration roller 4, an image forming unit 5 including a photosensitive drum and electrophotographic process means around the registration roller 4, and a fixing device are arranged in order from the upstream side in the conveying direction of the sheet P on the vertical conveying path of the sheet P as a transfer material extending upward from The part 6 is arranged. Also,
A switching claw 7 is provided on the downstream side of the fixing unit 6, and the paper P having passed through the fixing unit 6 by the switching claw 7 is discharged to a discharge tray 11 on the upper surface of the apparatus main body 1. And is sent to one of the reversing-side conveyance paths 9 for conveying to the duplex unit 2 side. A paper discharge roller 10 is provided downstream of the paper discharge path 8, and the paper discharge roller 10 is provided at a position facing the paper discharge tray 11.

The reversing side conveyance path 9 communicates with an upper opening 22a which is an entrance of the sheet P of the duplex unit 2.
The paper P is sent into the duplex unit 2 through the reverse-side transport path 9. When an image is formed on both sides, the switching claw 7 rotates clockwise about the support shaft 7 a to cause the sheet P, which has passed through the fixing unit 6, to be directed to the reversing side conveyance path 9.

The double-sided unit 2 has a retreat path 26 and a transport path 27 extending from the retreat path 26 to the registration roller 4 of the apparatus main body 1. The transport path of the transport path 27 is defined by a transport guide plate 28 as a guide member. Accordingly, the leading end of the sheet P conveyed to the duplex unit 2 is temporarily moved to the retreat path 2 by the conveying roller pairs 23 and 24.
6 is switched back by the transport roller pair 24, and the transport path 2
7, re-enters the apparatus main body 1 through the lower opening 22 b, and is sent to the registration roller 4 so that the surface opposite to the surface on which an image is first formed faces the image forming unit 5. Can be

Thus, the sheet P re-fed to the image forming unit 5
After the image is formed on the back side, the image on the back side is fixed by the fixing unit 6, and the sheet is stacked on the paper discharge tray 11 by the paper discharge roller 10. At this time, the switching claw 7 rotates in the counterclockwise direction, and the sheet P is not conveyed to the reverse conveying path 9 side.

The apparatus main body 1 is provided with a duct 30 and a fan 31 on the upper side as means for cooling the image forming section 5 and the fixing section 6, and the air of the image forming section 5 and the fixing section 6 is cooled by the apparatus main body 1. It is designed to exhaust outside.

Exterior 34 of double-sided unit 2 on the apparatus body 1 side
Is formed with an opening 32, and a fan 29 is attached to the opening 32 so as to discharge air from the opening 32. An opening 33 for taking in outside air is formed in a lower portion of the exterior 34 of the duplex unit 2. An opening 36 is formed on the exterior 35 of the apparatus main body 1 corresponding to the opening 32 so as to match the opening 32. This opening 36 serves as an intake port in the apparatus main body 1. The opening 36 is desirably formed at the boundary between the image forming unit 5 and the fixing unit 6 as illustrated. Further, the air taken into the apparatus main body 1 by the fan 29 is exhausted to the outside by the fan 31 through the duct 30.

As described above, in the first embodiment,
When the duplex unit 2 is mounted, air from a fan 29 that cools the duplex unit 2 is also supplied to the image forming unit 5 and the fixing unit 6 in the apparatus main body 1. Since the flow of air between the image forming unit 5 and the fixing unit 6 is generated by the two fans 29 and 31, the flow is smoother and the cooling efficiency is improved as compared with the case where the double-sided unit 2 is not provided. If the temperature rise in the apparatus main body 1 is small and the duct 30 and the fan 31 are not required inside the apparatus main body 1 when the duplex unit 2 is not mounted, this is not the case.
By providing the double-sided unit 9, the cooling efficiency can be improved when the double-sided unit 2 is mounted, as compared with the case where the double-sided unit 2 is not provided.

Note that the fan 29 reverses the blowing direction,
The air may be exhausted from the inside of the apparatus main body 1. In addition, the fan 29 is controlled so as to operate only when operated to form an image on both sides of the sheet P, thereby saving power.

In the first embodiment, air is blown between the image forming section 5 and the fixing section 6 which are heat sources inside the apparatus main body 1, so that the heat of the fixing section 6 can be removed. In addition, the influence of the temperature rise on the image forming unit 5 can be reduced. The place where the air is blown from the duplex unit 2 is not limited to the fixing unit 6, but may be another heat source such as a power supply or a polygon motor.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a cross-sectional view illustrating a configuration of a duplex unit according to a second embodiment of the present invention, and FIG. 3 is a partially cutaway perspective view illustrating a configuration of a guide plate in the duplex unit. is there.

That is, in the second embodiment,
A plurality of heat dissipating fins 41 are provided at intervals on the rear surface of the transfer guide plate 28 constituting the transfer path 27 so as to form a duct, and a cover plate 42 is provided on the upper edge of the heat dissipating fin 41. The fan 29 is arranged such that the outside air taken in from the opening 33 flows along the radiating fins 41 and is sent from the opening 32 to the opening 36 of the apparatus main body 1. As a result, the heat radiation effect of the transport guide plate 28 is increased, and the sheet P is indirectly cooled. As a result, an effect of alleviating a rise in temperature inside the apparatus main body 1 can be obtained. In this case, the radiation fins 41 can be further enhanced by forming the radiation fins 41 from a material having a high thermal conductivity, for example, a metal plate.

Further, since the radiation fins 41 are formed in a duct shape, the position at which air is blown to the apparatus main body 1 side,
The area, direction, and the like can be easily adjusted. Therefore, if air is blown toward the heat source of the apparatus main body 1 by the duct-shaped radiating fins 41, the inside of the apparatus main body 1 can be cooled in addition to the cooling of the paper P.
The temperature rise can be prevented efficiently. Furthermore, since the radiation fins 41 are formed in a duct shape, the degree of freedom in arranging the fans 29 in the double-sided unit 2 is increased, so that there is an advantage that the space in the double-sided unit 2 can be used effectively.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a configuration diagram schematically showing an overall configuration of an image forming apparatus according to the third embodiment of the present invention. In the third embodiment, a fan 29 is disposed so as to face the surface of the conveyance guide plate 28 of the duplex unit 2 on the side of the conveyance path 27.

By arranging the fan 29 in this way, the sheet P is cooled when the sheet P is passing through the transport path 27 of the duplex unit 2, and when the sheet P is not in the transport path 27, Sucks the air from the fan 29, so that the sheet P can be cooled in addition to the cooling of the apparatus main body 1. Further, a fan 29 and an opening 3 of the apparatus main body 1 for sucking air from the fan 29 are provided.
6 is set longer than the longest sheet P in terms of machine specifications, and it takes a little time from when the trailing edge of the sheet P passes through the fan 29 to when the leading edge of the sheet P reaches the inside of the apparatus main body 1. Is left, the air from the fan 29 flows into the apparatus main body 1 without hitting the paper P during that time, the amount of air flowing inside the apparatus main body 1 increases, and the cooling efficiency is improved. be able to.

Finally, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a configuration diagram schematically showing an overall configuration of an image forming apparatus according to the fourth embodiment of the present invention. In the third embodiment, the fan 2
9 is arranged above the duplex unit 2,
The hot air above the fixing unit 6 of the apparatus main body 1 is released to the outside of the duplex unit 2 via the fan 29 together with the air inside the unit. Therefore, an exhaust opening 51 is formed in the upper part of the exterior 34 of the double-sided unit 2. In this case, although the cooling effect can be expected even if the exhaust is not performed above the heat source, the air of the heat source inside the apparatus main body 1 is exhausted further upward, so that the air flow can be smoothly increased by using the ascending airflow. And exhaust can be efficiently exhausted.

[0029]

As is apparent from the above description, according to the first aspect of the present invention, the fan cools the inside of the double-sided unit, and the fan circulates cooling air into the image forming apparatus main body. Therefore, the inside of the apparatus can be cooled without unnecessary cost increase.

According to the second aspect of the present invention, the radiation fins are provided on the side of the guide member opposite to the transfer material conveying surface, and the air is supplied to the inside of the image forming apparatus through the air on the back surface of the guide member by the fan. The members can be efficiently cooled, and the image forming apparatus main body can be cooled.

According to the third aspect of the present invention, since the fan is disposed in the double-sided unit so as to face the main body of the image forming apparatus with the reversing conveyance path interposed therebetween, the transfer material passes through the conveyance path of the double-sided unit. When passing, the transfer material is cooled,
When there is no transfer material, the image forming apparatus main body side is also cooled, so that the transfer material can be surely cooled in addition to the image forming apparatus main body.

According to the fourth aspect of the present invention, since the fan is provided so as to guide the air above the fixing unit to the outside of the apparatus, the fan together with the air in the duplex unit and the fixing unit in the image forming apparatus main body. The hot air from above can escape to the outside from the duplex unit via the fan, and the air flow can be made smooth by utilizing the ascending airflow, whereby the air can be efficiently exhausted.

According to the fifth aspect of the present invention, an opening for allowing cooling air to flow inside the duplex unit and inside the image forming apparatus main body is provided at a position exposed to the exterior of the duplex unit exterior. Therefore, intake and exhaust of external air can be performed easily and reliably.

[Brief description of the drawings]

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

FIG. 2 is a side view for explaining a configuration of a duplex unit according to a second embodiment of the present invention.

FIG. 3 is a perspective view illustrating a configuration of a guide plate in a double-sided unit according to a second embodiment.

FIG. 4 is a configuration diagram schematically illustrating an overall configuration of an image forming apparatus according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram schematically showing an overall configuration of an image forming apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Double-sided unit 3 Paper feed cassette 5 Image forming part 6 Fixing part 7 Switching claw 8 Discharge path 9 Reverse transport path 25 Reverse path 27 Transport path 28 Transport guide plate 29 Fan 32, 33, 36, 51 Opening 34, 35 Exterior 41 Heat radiation fin P Paper

Claims (5)

[Claims] 1. An image forming apparatus main body including respective process elements for forming an image by an electrophotographic process, and a detachably provided main body of the image forming apparatus. A transfer material is carried in from the image forming apparatus main body. And a duplex unit for reversing the carried-in transfer material in a reversing path defined by the guide member and carrying it out to the image forming apparatus main body, wherein the inside of the duplex unit is cooled by the duplex unit. An image forming apparatus provided with a fan for circulating cooling air inside the image forming apparatus main body. 2. The image forming apparatus according to claim 1, wherein a radiation fin is provided on a side of the guide member opposite to the transfer material conveying surface, and the fan supplies air into the main body of the image forming apparatus by passing air through a back surface of the guide plate. The image forming apparatus as described in the above. 3. The image forming apparatus according to claim 1, wherein the fan is disposed in the double-sided unit so as to face the image forming apparatus main body with the reversing path interposed therebetween. 4. The image forming apparatus according to claim 1, wherein the fan is provided so as to guide air above the fixing unit out of the apparatus. 5. An opening for allowing cooling air to flow inside the duplex unit and inside the image forming apparatus main body at a position exposed to the outside of the exterior of the duplex unit. The image forming apparatus according to claim 1.