JPH1195641A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a recording paper on which a toner image is transferred to be preliminarily heated before the toner image is thermally fixed by a fixing device without increasing a new heating means in an image forming device equipped with the fixing device thermally fixing the toner image transferred on the recording paper from an image forming unit and a belt carrying device carrying the recording paper on which the toner image is transferred to the fixing device by sucking it to the surface of a belt by a sucking action. SOLUTION: This device is provided with a heat guiding component body 6 guiding heat radiated from the fixing device 5 to the surface of the belt 43 while simultaneously using the sucking action of the belt carrying device 4. The component body 6 is the box-like structural body 60 disposed on at least the upper side of the fixing device so that the heat radiated from the fixing device is collected in an inside space, for example. Then, the part of the box-like structural body 60 opposed to the belt surface of the carrying device 5 is provided with an opening 62 on which the sucking action of the carrying device 4 acts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, and a multifunction machine using a heat fixing method, and more particularly, to a method of heating and fixing a recording sheet after a toner image is transferred. And an image forming apparatus that can be preliminarily heated in the step (a).

[0002]

2. Description of the Related Art An image forming apparatus utilizing a heat fixing method forms a toner image corresponding to predetermined image information by an image forming unit including, for example, a photoreceptor, an image exposing device, a developing device, and a transfer device. After the toner image is transferred to the recording paper, the recording paper on which the toner image has been transferred is conveyed to a fixing device of a heat fixing method, whereby the toner of the toner image is heated and melted and fixed on the recording paper. . In a fixing device that performs such heat fixing, the higher the speed of a high-speed machine or a color image forming device, the higher the fixing temperature, and the ambient temperature around the fixing device tends to increase due to heat released from the main body of the device. To get stronger,
As shown in FIGS. 8 and 9, a heat collecting duct 02 is disposed above the fixing device 01 for the purpose of suppressing the temperature rise.
A heat exhausting facility is provided for discharging heat (high-temperature air, dotted line in FIG. 9) emitted from the fixing device main body to the outside of the apparatus main body through a heat collecting duct 02 by an exhaust fan 03. .

In this type of image forming apparatus,
As a transport unit for transporting the recording paper on which the toner image has been transferred by the image forming unit to the fixing device,
For example, as shown in FIGS. 8 and 9, between the transfer unit of the image forming unit and the fixing device 01, a suction-type belt conveyance for adsorbing and conveying the recording paper P to the surface of the conveyance belt by the suction action. Some use the device 04. The suction type belt transport device 04 is disposed in a state of being stretched around a plurality of support rolls 07 so that a transport belt 06 provided with a large number of air holes 05 rotates along the paper transport direction. And the conveyor belt 0
6, an intake section composed of an intake fan 08, an intake exhaust duct 09, and the like is disposed, and the recording sheet P after transfer onto the surface of the transporting belt 06 that rotates and travels is acted on by the intake section. (The solid line with an arrow in FIG. 9) is used to convey the sheet in a sucked state.

[0004] The suction type belt conveying device is relatively far from the image forming unit (transfer section) for the purpose of minimizing the adverse effect of the heat released from the fixing device and the space for installation. The image forming apparatus is frequently used in an image forming apparatus disposed at a position, thereby enabling the recording sheet after the transfer of the toner image to be stably conveyed to the fixing device in a correct conveying posture.

[0005]

In an image forming apparatus utilizing a heat fixing method, especially when coated paper (so-called coated paper) is used as the recording paper,
Due to the rapid heating by the fixing device, air existing between the coating layer of the coated paper and the toner of the toner image does not escape to the base material side of the paper and thermally expands into bubbles. In some cases, troubles occur in that satisfactory fixing is not performed and image quality is reduced.

Incidentally, in order to reduce the generation of bubbles during the heating and fixing of such coated paper, it is effective to heat the coated paper on which the toner image has been transferred before heating and fixing the coated paper. It is known that there is.

Therefore, for example, a countermeasure method is conceivable in which a dedicated heating means for preliminarily heating the recording paper before fixing is provided in the middle of the paper transport path on the upstream side of the fixing device. In order to avoid this, it is necessary to newly add a heating means, which leads to an increase in complexity and size and cost of the apparatus, and furthermore, it is necessary to separately take measures to exhaust heat generated when the heating means is heated. Taking measures against the exhaust heat may further increase the complexity, size, and cost of the device.

An object of the present invention is to provide an image forming apparatus which can preliminarily heat a recording sheet on which a toner image has been transferred before performing heat fixing by a fixing device without adding a new heating means. Is to do.

[0009]

The present inventor has conducted intensive studies to achieve the above object. As a result, in an image forming apparatus of the heat fixing type, as described above, heat released from the fixing device in the machine is used. Focusing on the fact that the heat is simply discharged outside the apparatus body to prevent the temperature rise, the heat released from the fixing device is used as a heat source, and the above-described suction operation of the belt transport device is applied to the heat belt surface. The present inventors have found that the recording paper after transfer can be preliminarily heated before heat-fixing without adding a new heating means by using the medium as a guiding member of the present invention, thereby completing the present invention.

That is, an image forming apparatus according to the present invention comprises: an image forming unit for forming a toner image and transferring the toner image to recording paper; a fixing device for heating and fixing the toner image transferred from the image forming unit to the recording paper; An image forming apparatus disposed between the transfer unit of the image forming unit and the fixing device, and having a belt conveyance device for adsorbing the recording paper on which the toner image has been transferred to the belt surface by suction and conveying the recording paper to the fixing device; , A heat induction component for guiding the heat released from the fixing device to the belt surface while using the suction action of the belt conveying device.

In this means, the heat released from the fixing device by the heat induction structure is guided to the belt surface while being assisted by the suction action of the belt conveying device. Then, the heat guided to the belt surface is supplied to the recording sheet which is adsorbed and conveyed to the belt surface of the belt conveying device after the transfer, and as a result, the recording sheet is preliminarily heated.

The heat induction component is not particularly limited as long as it can guide the heat released from the fixing device to the belt surface while using the suction action of the belt conveying device. For example, a box-shaped structure disposed at least above the fixing device so as to collect heat released from the fixing device in an internal space, and a belt surface of the belt conveying device of the box-shaped structure. An opening to which the suction action of the belt conveying device is exerted is provided at the opposing portion.

[0013] In the case of the heat induction structure composed of the box-shaped structure, the heat released from the fixing device is collected in the box-shaped structure, and then conducted to the belt surface through the opening by the suction action of the belt conveying device. I will As the box-shaped structure, it is desirable to effectively use a heat-exhaust duct that is already installed to take measures against heat-discharge of the fixing device.

[0014] In the heat induction structure composed of the box-shaped structure, the heat collected in the box-shaped structure is more reliably taken out and guided to the belt surface side to open the box-shaped structure. It is desirable to attach a blower fan to the opening.

Further, the heat induction member is a heat absorbing member disposed at least above the fixing device so as to absorb heat emitted from the fixing device. The end on the side of the conveyor may have a shape protruding toward the side of the belt conveyor.

In the case of the heat induction member composed of this heat absorbing member, after the heat released from the fixing device is absorbed by the heat absorbing member, the end portion of the protruding shape to which the suction action of the belt conveying device is exerted. From the belt surface. As the heat absorbing member, any member having a property capable of absorbing and retaining heat (specifically, iron, aluminum, stainless steel, or the like) may be used. For example, a heat sink (thermal conductor) is used. be able to.

[0017]

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

<First Embodiment> FIG. 1 is a schematic diagram showing the overall configuration of an image forming apparatus according to an embodiment of the present invention. In this image forming apparatus, an image forming unit 2 using an intermediate transfer method, a sheet feeding unit 3, a suction type belt transport device 4, and a fixing device 5 of a heat fixing type are arranged in the apparatus main body 1. , The main part is constituted. When the image forming apparatus is configured as a copying machine, an image reading device for reading image information of a document to be copied is further provided, although not shown. In the case where the printer is configured as a printer, an external input device for inputting image information to be printed from an external device or a recording medium is further provided, although not shown.

The image forming unit 2 includes black (B),
Four image forming units 20K, 20Y, 20M, and 20C for forming toner images of yellow (Y), magenta (M), and cyan (C) color components, respectively, are formed by the image forming units 20. And an intermediate transfer section 21 for first-transferring the toner image onto the intermediate transfer belt and then secondary-transferring it onto recording paper. Four image forming units 20K, 2
Reference numerals 0Y, 20M, and 20C denote a photosensitive drum 22 which rotates in the direction of arrow a, and image forming-related devices disposed around the photosensitive drum 22, that is, a charger 23, an image exposure device 24, and a developing device 25. , Primary transfer unit 26, cleaner 2
7 and the like. Further, the intermediate transfer unit 21
Is an intermediate transfer belt 28 that is stretched over a plurality of support rolls and rotates in the direction of arrow b in synchronization with the photosensitive drum 10 in a state of being in contact with the photosensitive drum 22 in each of the image forming units 20; The secondary transfer device 29 is roughly configured. Although not shown, a cleaner, a static eliminator, and the like are provided around the intermediate transfer belt 28.

The paper feed section 3 is roughly composed of a plurality of paper feed trays 30 each storing various types of recording paper P, and a sending device 31 for feeding out the recording paper in the paper feed tray 30 one by one. After the recording paper P sent from a predetermined paper feed tray 30 is passed through a paper transport path (dashed line) constituted by a plurality of roll pairs 32, a paper guide member, and the like,
Paper is fed up to the registration roll 33 disposed in front of the secondary transfer device 29 of the image forming unit 2.

The belt conveying device 4 includes the image forming unit 2
Are arranged before and after between the secondary transfer device 29 and the fixing device 5. Basically, each of them is basically a belt transport unit 40 on which a belt for actually transporting the recording paper P is disposed.
And a suction unit 41 that suctions the recording paper P to be attracted to the belt surface of the belt conveyance unit 40. As shown in FIG. 1 and FIG. 2, the belt transport unit 40 is configured such that a plurality of transport belts 43 provided with a large number of air holes 42 are stretched over a plurality of support rolls 44 at intervals. It is configured to rotate and travel along the transport direction. On the other hand, as shown in FIGS. 1 and 2, the intake section 41 has an intake duct 45 installed below the belt transport section 40, and an exhaust port connected to the intake duct 45 and located at the rear of the apparatus main body 1. Exhaust duct 4 installed up to
6 and an intake fan 47 disposed at a predetermined position of the intake duct 45 or the exhaust duct 46. The rotation of the intake fan 47 causes an intake action in the intake duct 45, and the belt conveyance unit 40. The air existing above the belt 43 passes through the air holes 42 and the like of the belt 43 and is sucked into the intake duct 45, and the sucked air is discharged out of the apparatus main body 1 through the exhaust duct 46. Has become.

The fixing device 5 passes through a nip portion between the heating roll 51 and the pressure roll 52, which are arranged to rotate while being pressed against the inside of the housing 50, and the nip portion between the two rolls 51, 52 (after fixing). The main part thereof is constituted by a feeding roll 53 for feeding the recording paper out of the housing 50). The press roll 43 may be a heat press roll. The recording paper after fixing is usually
The sheet is immediately discharged to the outside of the apparatus main body 1 by the discharge roller 34. However, if necessary, three roll pairs 35 for switching the transport direction of the paper and transporting the paper, and a reversing roll that can be rotated forward and backward. After being drawn into the sheet reversing path constituted by the pair 36, the sheet is discharged out of the apparatus main body 1 in a state where the front and back surfaces of the sheet are reversed.

The (color) image formation by this image forming apparatus is basically performed as follows.

First, each of the image forming units 20K, 20Y, 20
At M and 20C, toner images of predetermined color components are formed, respectively. That is, in each image forming unit 20, after the rotating photosensitive drum 22 is charged by the charger 23,
A light image based on image information is scanned on the charged drum surface by the image exposure device 24 to form an electrostatic latent image of a predetermined color component. Thereafter, the electrostatic latent image is supplied from the developing device 25. The toner image is developed by the toner.
Next, the respective toner images formed on the respective photosensitive drums 22 in the respective image forming units 20 are sequentially primary-transferred to the intermediate transfer belt 28 of the intermediate transfer unit 21 by the respective primary transfer units 26 and are superimposed. After the primary transfer, the surface of the photosensitive drum 22 is cleaned by removing the toner and the like remaining on the surface by the cleaner 27.

The composite toner image transferred onto the intermediate transfer belt 28 is transferred from the paper supply unit 3 to a recording paper P which is fed by a registration roll 33 to the secondary transfer device 29 at a predetermined timing. The secondary transfer is performed collectively by a roll type secondary transfer device 29. The recording paper P after the completion of the secondary transfer is conveyed to the fixing device 5 while being separated from the intermediate transfer belt 28 and adsorbed on the belt 43 of the belt conveying device 4, and is heated by the heating roll 51 of the fixing device 5. The toner composite image is heated and fixed by passing through the nip with the pressure roll 52. Then, the recording paper P after the completion of the fixing is sent out of the housing 50 by the sending roll 53 and is then discharged to the outside of the apparatus main body 1 by the discharge roll 34. The belt surface of the intermediate transfer belt 2 after the secondary transfer is cleaned by a cleaner or discharged by a discharging device. By performing the above operations, a color toner image is formed on the recording paper P.

In this image forming apparatus,
As shown in FIGS. 1 and 2, heat released from the fixing device 5 is transferred to a belt transport device 4 disposed downstream in the sheet transport direction.
The heat induction component 6 for guiding to the surface of the belt 43 while using the suction action of the suction section 41 is also provided.

The heat induction structure 6 according to this embodiment includes:
As shown in FIG. 2 and FIG.
Is formed by a heat collecting duct 60 having a hollow structure, which is disposed so as to cover the upper side of the housing at a predetermined interval.
The heat collecting duct 60 is formed of a metal plate or a heat-resistant plastic plate so that at least the lower surface 60 a has a shape substantially corresponding to the outer shape of the housing 50 of the fixing device 5. Opposing surface 60b whose end substantially faces at least a part of the belt 43
It consists of a box-shaped structure formed so that it becomes. A large number of heat intake holes 61 for taking in heat released from the fixing device 5 (actually, the housing 50) into the duct are provided on the lower surface 60a of the box-shaped structure.
Are provided on the opposite surface 60b so that a plurality of openings 62 are uniformly distributed over the entire surface. The facing surface 60b and the opening 62 are at least
What is necessary is just to be formed so that the intake action of
The size, shape, etc., are not particularly limited.

By providing the heat induction structure 6 including the heat collection duct 60, during image formation, heat released from the fixing device 5 passes through the heat induction structure 6 as described in detail below. The belt is guided to the surface of the belt 43 of the belt transport device 4.

That is, in this image forming apparatus, when the power of the apparatus main body is turned on, the heating is controlled so that the heating roll 51 of the fixing device 5 is maintained at the fixing temperature until the power is turned off thereafter. It has become. As a result,
As shown in FIG. 3, the heat (dotted line in the figure) generated from the heating roll 51 of the fixing device fills the housing 50 and is released outside the housing 50. The heat released from the fixing device 5 in this manner is
By ascending, the heat is collected by being introduced into the duct through a heat intake hole 61 provided in the lower surface 60 a of the heat collection duct 60. On the other hand, when the image forming operation is started, the belt conveyance unit and the suction unit 4 of the belt conveyance device 4 are started.
1 is activated. As a result, the intake section 41
When the suction fan 46 rotates, a suction action (solid line with an arrow in the drawing) is generated, so that the air above the belt 43 is sucked into the suction duct 45 through the ventilation holes 42 and the like of the belt 43. When the suction action reaches the opening 62 formed on the facing surface 60 b of the heat collection duct 60, the heat collected inside the heat collection duct 60 passes through the opening 62 and is taken out of the duct. 45, and is consequently guided to the surface of the belt 43 (strictly speaking, while the heat collides with the belt surface, the heat is applied to the ventilation holes 4).
2 flows into the intake duct 45).

Therefore, in this image forming apparatus, the heat released from the fixing device 5 is guided to the surface of the belt 43 of the belt conveying device 4 through the heat induction member 6, so that the belt 43 is warmed by the heat and The heat directly contacts the recording paper P after transfer, which is absorbed and conveyed to the belt 43 surface. As a result, the recording paper P after the transfer is heated from the lower surface of the paper by the heated belt 43 before being sent to the fixing device 5, and
The sheet is heated from the upper surface side of the sheet by heat guided from the heat induction structure 6 to the belt surface.

Thus, even when coated paper is used as the recording paper P, the coated paper is preliminarily heated in the course of being conveyed by the belt conveying device 4 and then transferred to the fixing device 5. Since it is fed, there is no rapid heating during heat fixing. For this reason, in the coated paper on which such preliminary heating is performed, bubbles generated at the time of heating and fixing as in the related art are eliminated or reduced. Then, the belt 43 is passed through the heat induction structure 6.
The heat guided to the surface is finally exhausted out of the apparatus main body 1 through the exhaust duct 46.

In the image forming apparatus according to this embodiment, the heat released from the fixing device 5 is effectively used to guide the heat to the recording sheet after the transfer by guiding the heat to the belt surface side of the belt conveying device 4. By discharging to the outside through the exhaust duct of the belt conveying device 4 later,
Unlike the conventional device (FIG. 8), there is no need to provide heat exhaust equipment (exhaust duct, intake fan, etc.) on the fixing device 5 side.

<Second Embodiment> An image forming apparatus according to a second embodiment has the same configuration as the image forming apparatus of the first embodiment except that the configuration of the heat induction structure 6 is partially changed. is there. That is, as shown in FIG. 4 and FIG. 5, the heat induction component 6 in this embodiment uses the heat collection duct 60 of the heat induction component 6 in the first embodiment under almost the same conditions. In addition, a blower fan 65 is attached to the facing surface 60b of the heat collection duct 60. The blower fan 65 is for sucking out the heat collected in the heat collecting duct 60 and gently sending it toward the surface of the belt 43, and is provided on the facing surface 60b facing the belt 43 as shown in FIG. It is attached around the opening 62. In this example, two low power type fans are used as the blower fan 65. However, if the type and quantity of the fan can be satisfied as long as they do not adversely affect the conveyance state of the recording paper or the transferred toner image,
There is no particular restriction.

In the heat induction structure 6 of this embodiment, as shown in FIG.
b, an air blowing action (broken line with an arrow in the figure) of the blowing fan 65 is generated, so that heat from the fixing device 5 collected inside the duct of the heat collecting duct 60 is sucked out, and the heat is collected on the surface of the belt 43. Sent to. At this time, the heat sent by the blower fan 65 is transferred to the belt conveying device 4.
Is also guided to the surface of the belt by the suction action of the suction section 41. Thereby, similarly to the case of the first embodiment,
Transferred recording paper P transported by belt transport device 4
Is preliminarily heated before heat fixing. In the case of this embodiment, the heat collected in the heat collecting duct 60 is more reliably sucked out of the duct by the blower fan 65 and guided to the surface of the belt 43. This can be performed more reliably.

Third Embodiment An image forming apparatus according to a third embodiment has the same configuration as the image forming apparatus of the first embodiment except that a heat absorbing member 70 is used as the heat induction component 6. It is. That is, the heat absorbing member 70 of the heat induction component 6 in this embodiment is disposed above the housing 50 of the fixing device 5 as shown in FIGS.
The end 70a on the side of the belt conveying device 4 is constituted by a heat absorbing member such as a heat sink having a shape protruding toward the belt conveying device 4. The protruding end 70a of the heat absorbing member 70 is disposed so as to face at least a partial area of the belt 43, and the (absorbed) heat is released from the end. A large number of cut grooves 71 are formed in order to facilitate the formation. By providing a large number of cut grooves 71, the surface area of the end portion 70a is greatly increased.

In the heat induction component 6 of this embodiment, as shown in FIG. 7, the heat released from the housing 50 of the fixing device 5 rises and is absorbed by the heat absorbing member 70. On the other hand, the protruding end 70 a of the heat absorbing member 70 is subjected to the suction action by the suction section 41 of the belt conveyance device 4. As a result, the heat absorbed by the heat absorbing member 70 is deprived of the end portion 70a by the above-described suction action, and the belt 4
It is led to the 3rd side. As a result, similarly to the first embodiment, the transferred recording sheet P conveyed by the belt conveying device 4 is preliminarily heated before heat fixing. In the case of this embodiment, the heat absorbing member 70 can be formed to have a thin thickness.
Heat collection duct 60 such as a box-like structure as in the embodiment
Therefore, the installation space is smaller than that of the first embodiment, and the size of the entire apparatus can be reduced.

<Modification> In each embodiment, the pre-heating of the recording paper before the transfer is performed only in the belt transport device disposed downstream (closer to the fixing device) of the two belt transport devices in the paper transport direction. Although it is configured to perform the heat transfer, the heat from the heat induction structure 6 may be configured to be guided to the belt surfaces of the two belt conveyance devices. In this case,
Preheating can be performed more efficiently and reliably.

In each of the embodiments, the image forming unit 2 employs an intermediate transfer system in which a toner image is transferred to recording paper via an intermediate transfer belt in two stages. One photosensitive drum 22
In this case, an image forming unit 2 configured to directly transfer a toner image from the photosensitive drum to recording paper may be used. In that case, the belt transport device 4 and the heat induction component 6 are disposed between the photosensitive drum and the fixing device 5.

[0039]

As described above, according to the image forming apparatus of the present invention, there is provided a heat induction structure for guiding the heat released from the fixing device to the belt surface while using the suction action of the belt conveying device. Therefore, the recording paper to which the toner image has been transferred can be preliminarily heated before performing the heat fixing by the fixing device without adding a new heating unit.

Thus, even when coated paper is used as the recording paper, the coated paper is heated and fixed after being preliminarily heated, so that it is not suddenly heated. Therefore, the generation of bubbles during heating and fixing is eliminated or reduced, and it is possible to prevent defective fixing and deterioration in image quality due to the generation of bubbles. In addition, the heat induction component can be configured by effectively utilizing existing parts and equipment, thereby providing a special heating means for preliminarily heating the recording paper before heat fixing. Since there is no need to separately provide a separate device inside the forming device body,
There is no problem that the new heating means is added to increase the complexity and size of the apparatus and increase the cost.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a configuration of a heat induction component (heat collecting duct) of the first embodiment.

FIG. 3 is an explanatory view showing the principle of preheating performed by the heat induction component shown in FIG. 2;

FIG. 4 is a perspective view illustrating a configuration of a heat induction component (a heat collection duct with a blower fan) according to a second embodiment.

FIG. 5 is an explanatory view showing the principle of preheating performed by the heat induction component shown in FIG.

FIG. 6 shows a heat induction component (heat absorbing member) according to a third embodiment.
It is a perspective view which shows a structure of.

FIG. 7 is an explanatory view showing the principle of preheating performed by the heat induction component shown in FIG.

FIG. 8 is a perspective view illustrating a configuration example of a fixing device and a belt conveyance device in a conventional image forming apparatus.

9 is an explanatory diagram illustrating an operation state of the fixing device and the belt conveyance device illustrated in FIG. 8;

[Explanation of symbols]

Reference numeral 2 denotes an image forming unit, 4 denotes a belt conveying device, 5 denotes a fixing device, 6 denotes a heat induction member, 43 denotes a conveying belt, and 60 denotes a belt.
Heat collecting duct (box-shaped structure), 62: opening, 65: blower fan, 70: heat absorbing member, 70a: end portion on the belt conveying device side, P: recording paper.

Claims (4)

[Claims] An image forming unit that forms a toner image and transfers the toner image to recording paper; a fixing device that heats and fixes the toner image transferred from the image forming unit to recording paper; and a transfer unit of the image forming unit. A belt conveying device disposed between the fixing device and the recording medium to which the toner image has been transferred, the recording paper onto which the toner image has been transferred is attracted to a belt surface by an air suction action, and is conveyed to the fixing device. An image forming apparatus provided with a heat induction structure for guiding the heat to the surface of the belt while using the suction action of the belt conveying device. 2. A box-shaped structure, wherein the heat-inducing component is disposed at least above a fixing device so as to collect heat emitted from the fixing device into an internal space, and the box-shaped structure is provided. The image forming apparatus according to claim 1, wherein an opening is provided in a portion of the body facing the belt surface of the belt transport device, to which the suction operation of the belt transport device is applied. 3. A blower fan is attached to an opening formed in a portion of the box-shaped structure facing a belt surface.
The image forming apparatus as described in the above. 4. A heat absorbing member, wherein the heat induction member is disposed at least above a fixing device so as to absorb heat released from the fixing device, and the belt of the heat absorbing member is provided. The image forming apparatus according to claim 1, wherein an end on the side of the conveying device has a shape protruding toward the side of the belt conveying device.