Image forming apparatus

Abstract

To enable more efficient heat exhaustion than before.SOLUTION: An image forming device having an exhaust unit for exhausting heat from within a device is provided, the exhaust unit being provided on a side face of the image forming device and provided with a notch-shaped recess that is open above a position where heat is exhausted from the side face.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] In an electrophotographic image forming apparatus, an air flow path is installed to cool the inside of the image forming apparatus. In a configuration having an intake part or an exhaust part or both, when the outer surface of the image forming apparatus where the intake part or the exhaust part is formed is closely attached to the wall, it will be blocked. Therefore, a technique of recessing the outer surface of the image forming apparatus so as not to block the air flow path and allowing it to escape to the lower surface and the left and right surfaces is already known.

[0003] <00000第一行]]

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, when the rear, left, and right of the apparatus are simultaneously attached to the wall, there is a problem that the exhaust air flow cannot escape. Also, even when adopting a method of allowing the exhaust air flow to escape downward, there is a problem that the space is narrow and heat is likely to be trapped. In particular, in the exhaust part, since heat has the property of rising, there is a problem that heat cannot escape appropriately to the outside. Furthermore, although the exhaust part can be provided limited to the corner of the apparatus, in this configuration, the range for allowing the exhaust air flow to escape is narrow, and heat at a position away from the corner cannot necessarily be escaped. Thus, in the conventional technology, there is a problem that heat inside the apparatus cannot be escaped considering the characteristics of heat and exhausted efficiently.

[0005] An object of the present invention is to provide an image forming apparatus capable of exhausting heat more efficiently than the conventional one.

Means for Solving the Problems

[0006] The image forming apparatus according to the present invention is an image forming apparatus having an exhaust unit for exhausting heat from inside the apparatus, wherein the exhaust unit is the image forming apparatus Seiso It has a notched recess provided on the side of the base, with an opening above the position where the heat is exhausted from the side. The upper opening that forms the notch shape has a portion that protrudes outward from the bottom surface of the recess, thereby forming the recess as a depression. It is configured as an image forming apparatus characterized by the following features. [Effects of the Invention]

[0007] According to the present invention, heat can be exhausted more efficiently than in the conventional method. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the overall configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] Figure 1 is a cross-sectional view conceptually showing the internal structure of the image forming apparatus. [Figure 3] This is a view from the direction of arrow A (rear side of the device) in the schematic diagram of the device body (Figure 1). [Figure 4] This is a cross-sectional view of the area around the fan where a notch has been cut out and recessed on the upper side. [Figure 5] This figure shows an example of exhaust when there is a wall on the back side of the device. [Figure 6] This figure shows an example where there is a recess above the duct or fan location, forming a recessed area without a notch. [Figure 7] This diagram shows how a wall lower than the main unit of the device is positioned to block the duct. [Figure 8] This figure shows an example where an outer cover is attached to the main body of the device, and the airflow of heat discharged from ducts and fans flows to the upper side of the main body of the device, with the filter being detachably positioned. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will now be described. The present invention has the following features in relation to a heat exhaust duct. In short, in an electrophotographic image forming apparatus, an airflow path is installed to cool the inside of the image forming apparatus, and in a configuration in which the airflow path has an exhaust section, the exhaust section is blocked if the outer surface of the image forming apparatus is placed flush against a wall. Therefore, the outer surface of the image forming apparatus is recessed to prevent the airflow path from being blocked, and the airflow is configured to escape upward. Furthermore, a feature of the present invention is that the duct is constructed so that the path is formed from the exhaust surface to the upper surface, rather than having a diagonal recessed shape at the corner. The features of the present invention described above will be explained in detail with reference to the following drawings.

[0010] Figure 1 is a perspective view showing the overall configuration of an image forming apparatus according to an embodiment of the present invention, and Figure 2 is a cross-sectional view conceptually showing the internal structure of the image forming apparatus shown in Figure 1.

[0011] The in-cylinder paper-discharge type color copier 1 of this embodiment mainly consists of a roughly box-shaped device body 10 with an open top surface, which is the housing of the entire image forming apparatus; an image reading unit 2 located at the top of the device body 10 for reading the image of the original document; an image forming unit 3 located below the image reading unit 2 for forming an image based on the image information read by the image reading unit 2 or transmitted by an external device; a paper feeding unit 4 located at the bottom of the device body 10 for supplying recording media P (hereinafter referred to as paper P) such as paper (referring to sheet-like materials including copy paper, resin sheets for OHP, cardboard, postcards, etc.; the same applies hereinafter); a paper discharge unit 5 located above the image forming unit 3 for discharging the paper P; and a paper transport path 6 located between the paper feeding unit 4 and the paper discharge unit 5.

[0012] The image reading unit 2 is attached to the top surface of the main body 10 of the device and consists of a contact glass 20 which serves as a document tray on which the document is placed, a light source 21 which is positioned directly below the contact glass 20 and moves while illuminating the document, an imaging lens 22 which forms an image of the reflected light from the document, an image sensor 23 such as a CCD which is positioned at the imaging position and serves as a reading means for reading the document image, and multiple mirrors which reflect the reflected light from the document and guide it to the imaging lens 22. In addition, a pressure plate 24 is provided on the upper part of the image reading unit 2 to hold down the document placed on the contact glass 20 (shown in Figure 2, Figure 1 is omitted). Note that there is also a structure in which an automatic document feeder (ADF) is installed to automatically feed the document onto the contact glass 20 instead of the pressure plate 24, but this is well known so it is not shown or explained.

[0013] The image forming unit 3 consists of four process cartridges 3Y, 3M, 3C, and 3K corresponding to a total of four toner colors: yellow, magenta, cyan, and black; a writing unit 30 located below these four process cartridges 3Y, 3M, 3C, and 3K that writes latent images to each of the photosensitive drums; four toner bottles 31Y, 31M, 31C, and 31K that contain new toner of the colors corresponding to each of the process cartridges; a transfer unit 32 that first transfers the images formed by each process cartridge to the paper P; and a fixing unit 33 that fixes the images to the paper P.

[0014] Process cartridges 3Y, 3M, 3C, and 3K are arranged along the lower surface of the intermediate transfer belt 32a, described later, in the order of yellow, magenta, cyan, and black from the upstream side in the direction of movement of the outer peripheral surface indicated by the arrows in the figure. Each process cartridge 3Y, 3M, 3C, and 3K is an image-making device that is integrally molded and detachable from the main body 10, with a photoreceptor drum Y, M, C, K, which is a latent image carrier that rotates clockwise on the paper plane of Figure 2, at its center. The device includes a charging means that uniformly charges the outer peripheral surface of each photoreceptor drum Y, M, C, and K by applying an electrostatic latent image treatment, a developing means 30Y, 30M, 30C, and 30K that visualizes the electrostatic latent image formed on each photoreceptor drum Y, M, C, and K by the writing unit 30 described later into a monochromatic toner image using the corresponding toners, and a cleaning means that cleans and collects the remaining toner after transfer that remains on the outer peripheral surface of the photoreceptor drum Y, M, C, and K.

[0015] The writing unit 30 is an exposure device equipped with a polygon mirror and an fθ lens, which scans the image information input from the image reading unit 2, a personal computer, an external scanner, etc., while irradiating it with laser light from a laser light emitter, selectively exposing the outer surfaces of the uniformly charged photoreceptor drums Y, M, C, and K, lowering the surface potential of the irradiated area, and forming an electrostatic latent image on the photoreceptor drum.

[0016] Each toner bottle 31Y, 31M, 31C, and 31K is individually filled with the four colors of new toner mentioned above, and the toner of each color is supplied to the developing means 30Y, 30M, 30C, and 30K of each process cartridge 3Y, 3M, 3C, and 3K via a transport path not shown.

[0017] The transfer unit 32 is an intermediate transfer type transfer device mainly composed of an intermediate transfer belt 32a, which is an endless belt made of a multilayer structure of elastic resin as an intermediate transfer body; four support rollers 32b, 32c, 32d, and 32e that support and tension the intermediate transfer belt 32a; four primary transfer rollers 32f that face the photoreceptor drums Y, M, C, and K on either side of the intermediate transfer belt 32a; and a secondary transfer roller 32g that is positioned opposite the support roller 32b.

[0018] The support roller 32b is a drive roller connected to drive means (not shown), and has a function of rotationally driving the intermediate transfer belt 32a in the direction of the arrow in the figure. Note that a secondary transfer roller 32g is arranged at a position facing the support roller 32b (hereinafter referred to as the drive roller 32b) serving as the drive roller with the intermediate transfer belt 32a interposed therebetween, and a cleaning device 32h for scraping and cleaning the residual toner adhering to the outer peripheral surface of the intermediate transfer belt 32a is provided near the support roller 32c.

[0019] Each primary transfer roller 32f is a transfer bias (transfer voltage) applying means of the contact application method, is connected to a bias power source (not shown), and is configured to be able to apply a primary transfer bias from the back surface (inner peripheral surface) of the intermediate transfer belt 32a. The position of each primary transfer roller 32f is considered in view of image deterioration due to void discharge. That is, it is arranged at a position slightly shifted downstream in the surface movement direction of the intermediate transfer belt 32a from the facing position where the center-to-center distance between each photosensitive drum Y, M, C, K and the intermediate transfer belt 32a is the shortest distance and they are in contact.

[0020] The secondary transfer roller 32g is urged by urging means (not shown) and is pressed against the intermediate transfer belt 32a on the outer periphery of the drive roller 32b, and is configured to form a secondary transfer nip between the drive roller 32b. Further, the drive roller 32b is a contact-type transfer bias applying means connected to a bias power source (not shown). Note that the secondary transfer roller 32g may be used as the transfer bias applying means, and in that case, a transfer bias having a polarity opposite to that of the toner image to be transferred is applied.

[0021] The fixing unit 33 forms a fixing nip between a fixing roller 33a and a fixing belt 33c which is an endless belt stretched around a heating roller 33b, and a pressing roller 33d as a pressing member that presses against the fixing belt 33c. Heat and pressure are applied to the paper P conveyed through the paper conveyance path 6 described later in this fixing nip, and the toner image transferred at the secondary transfer nip of the transfer unit 32 described above is melted and adhered to the paper P for fixing.

[0022] The paper feeding unit 4 includes, for example, paper feed cassettes 40 and 41 capable of accommodating paper P of various sizes. The paper feed cassettes 40 and 41 are configured to be retractable from the main body 10 of the device and are equipped with paper feed rollers 42 and 43 that press against the stored paper P from above. Based on a control signal from a control means (not shown), the paper P stored in the paper feed cassettes 40 and 41 are fed by the paper feed rollers 42 and 43 to the paper transport path 6, which will be described later.

[0023] Furthermore, the paper feeding unit 4 is equipped with a manual feed tray 44 for placing any paper within a predetermined size range that can be transported, and a paper feed roller 45 for feeding out this paper. The paper placed in the manual feed tray 44 can be fed to the paper transport path 6, which will be described later, by rotating the paper feed roller 45.

[0024] The paper discharge unit 5 includes a paper discharge tray 50 consisting of a slanted portion formed between the aforementioned toner bottles 31Y, 31M, 31C, and 31K and the image reading unit 2, followed by a flat portion. The paper P discharged from the paper discharge port by the paper discharge roller pair 63 is then collected on the paper discharge tray 50. In other words, the illustrated example is a so-called in-cylinder paper discharge type paper discharge unit, but the present invention is not limited to image forming apparatuses having this type of paper discharge unit. This paper discharge unit is provided with means, which will be described later, for dissipating the heat generated in the aforementioned image forming unit 3 (image making unit).

[0025] The paper transport path 6 mainly consists of a normal transport path 60 that uses a vertical transport method (vertical pass method) to transport paper from the paper feeding section 4 located at the bottom of the main body 10 to the paper discharge section 5 located at the top of the main body 10, and a reverse transport path 61 that reverses the paper P for double-sided printing. These normal transport path 60 and reverse transport path 61 are equipped with multiple transport roller pairs at intervals corresponding to the minimum paper size, and these transport roller pairs rotate while gripping the paper P to transport the paper P.

[0026] In addition to the transport roller pair, the normal transport path 60 is equipped with a registration roller pair 62 below the secondary transfer nip and a paper discharge roller pair 63 near the end in the paper transport direction. The registration roller pair 62 adjusts the timing of transporting the paper P to the secondary transfer nip of the transfer unit 32 based on commands from a control means (not shown), and then transfers the image to the paper P at the secondary transfer nip. After that, the paper P passes through the fixing unit 33 to fix the image, and is discharged from the paper discharge port 64 onto the paper discharge tray 50 by the paper discharge roller pair 63.

[0027] The aforementioned switching between the normal transport path 60 and the reverse transport path 61 is performed by the switching claw 65. For example, when the paper P guided by the switching claw 65 leaves the normal transport path 60, the reverse transport roller pair 66 carries it to the upper transport path 67 of the reverse transport path 61, and the reverse transport roller pair 66 reverses, flipping the leading and trailing ends of the paper P in a switchback manner, and while it is being transported to the normal transport path 60 in front of the registration roller pair 62, the front and back sides of the paper P are flipped.

[0028] Next, the image forming operation of the illustrated color copier 1 will be described. When making a copy, first open the pressure plate 24 (shown in Figure 2, not shown in Figure 1) and place the original document on the contact glass 20 of the image reading unit 2. If an ADF is provided instead of the pressure plate 24, place the original document on the ADF's document glass. Next, when you press the start switch on the operation panel 71, the image reading unit 2 is driven, and light emitted from the moving light source 21 strikes the surface of the original document and is reflected. This reflected light is then reflected by multiple mirrors and passed through the imaging lens 22 to form an image on the image sensor 23. The image sensor 23 converts this into an electronic signal and reads the image (content of the original document). If an ADF is installed, the original document is automatically transported from the ADF's mounting table onto the contact glass 20 before the above operation is performed. Then, depending on the mode setting selected on the operation panel, the image formation operation is performed in full color mode or black and white mode.

[0029] When forming a color image in full-color mode, when the image formation operation is started in the color copier 1, each photoreceptor drum Y, M, C, and K is driven to rotate clockwise when viewed from the front of the color copier 1 (direction in Figure 1). At this time, the outer surfaces of each photoreceptor drum Y, M, C, and K are uniformly charged to a predetermined polarity (for example, negative) by each charging means. Next, laser light is irradiated onto each charged surface based on image information color-separated to correspond to the toner color from the writing unit 30, forming an electrostatic latent image on the outer surface of each photoreceptor drum Y, M, C, and K. Then, these electrostatic latent images are made visible as monochrome toner images by each developing means 30Y, 30M, 30C, and 30K, and a primary transfer bias is applied to each toner image of each color by the corresponding primary transfer roller 32f, and they are sequentially transferred onto the intermediate transfer belt 32a to form a full-color toner image. When forming a monochrome image in black and white mode, the above operation is performed using only the black process cartridge 3K.

[0030] Then, the paper P stored in the paper cassettes 40 and 41 of the paper feeding unit 4 is fed one sheet at a time into the paper transport path 6 by the paper feed rollers 42 and 43. The fed paper P moves upward along the paper transport path 6 and stops when its leading edge hits the registration roller pair 62. Even if the leading edge of the paper P is at an angle to the transport direction, this contact straightens it out. Next, the registration roller pair 62 is rotated in time with the timing when the color toner image formed on the intermediate transfer belt 32a reaches the secondary transfer nip, and the paper P is fed towards the secondary transfer nip of the transfer unit 32.

[0031] Next, a secondary transfer bias is applied at the secondary transfer nip of the transfer unit 32, and the full-color toner image on the intermediate transfer belt 32a is transferred to the paper P by electrostatic force. After that, the paper P is sent to the fuser nip of the fuser unit 33. There, heat and pressure are applied by the fuser belt 33c and pressure roller 33d, fixing the unfixed toner image on the paper P. After the toner image is fixed, the paper P is ejected onto the paper output tray 50 by the rotation of the paper output roller pair 63. When multiple sheets of paper P are ejected, they are stacked in the order of ejection as shown in Figure 2.

[0032] Furthermore, when double-sided mode is selected and double-sided copying is performed, the switching claw 65 switches the transport path, and the paper P with the image fixed on one side is temporarily stored in the upper transport path 67 of the reversal transport path 61. Then, the reversal transport roller pair 66 reverses the direction of travel in a switchback manner, the transport rollers transport the paper along the reversal transport path 61, and the paper is re-fed in front of the registration roller pair 62, and image formation (printing) on ​​the back side is performed in the same way as the image formation operation described above.

[0033] Furthermore, residual toner on the photoreceptor drums Y, M, C, and K is cleaned by the respective cleaning means, and then a bias with an AC component superimposed on DC is applied by the charging means, so that the photoreceptor drum is uniformly charged at the same time as being discharged. In addition, residual toner on the intermediate transfer belt 32a is cleaned by the cleaning device 32h, and the color copier 1 prepares for the next image forming operation.

[0034] Figure 3 is a view of the device body 10 from the direction of arrow A (rear side of the device body) in the schematic diagram (Figure 1). Around the fan 136 for exhausting heat from the device body 10, there is a recess cut out on the upper side (above the fan 136). A cross-sectional view of this area is shown in Figure 4. To dissipate heat from inside the main body, the fan 136 is rotated from the duct 137 to expel the heat from inside the device to the outside. If there are no obstacles on the back side, side A, the heat inside the device is discharged in a straight line as exhaust 508. In this embodiment, around the fan 136 on the back side of the device, a notch shape 138 is provided in the part of the device body that is above the downstream heat exhaust flow path that discharges heat from inside the device to the outside. With this configuration, for example, even if there is a wall B on the back side of the device as shown in Figure 5, the heat discharged from inside the device is exhausted upward as exhaust 507 due to the notch shape 138 and is not blocked by wall B.

[0035] In other words, in the device body 10, a notched recess is formed by a first exhaust surface 501 located at a horizontal position X2 at or near the same as the lower end position X1 of the fan 136 on the downstream side in the heat exhaust direction, where heat is exhausted by the fan 136, and a second exhaust surface 502 extending upward (approximately vertically upward in this example) from both sides in the width direction of the first exhaust surface 501, which is a side surface for guiding the hot airflow exhausted from the fan 136 to the top of the first exhaust surface 501, with the top of the recess being open. With this configuration, heat can be efficiently exhausted even if the back and sides of the device body 10 are blocked by a wall or the like. Conventionally, when heat with an upward characteristic is exhausted downward, the problem arises that heat accumulates and does not escape properly, but this problem can be resolved.

[0036] Furthermore, if the duct 137 and fan 136 are located at the bottom of the device body 10, the exhaust path can be secured by making the notch shape 138 longer in the vertical direction of the device. In other words, the second exhaust surface 502 described above can be extended further upward. In this way, by having a notch shape with an opening on the upper side of the device body 10, taking into account the characteristic of heat rising, heat from inside the device can be exhausted efficiently.

[0037] Furthermore, as shown in Figure 6, another example will be described in which there is a recess above the position of the duct 137 and fan 136 provided at the exhaust port of the device body 10. In this case, although the device body 10 has the above-mentioned recess, a portion 602 is formed above the recess, protruding from the bottom surface 503 of the recess toward the outer wall of the device, so a configuration like the recessed portion 601 without the aforementioned notch can be considered. With such a configuration, as shown in Figure 7, even if a wall 506 that is lower in height than the device body 10 is positioned to block the duct 137, heat can be exhausted 507 from a position that avoids that position. In other words, even if the above-mentioned first exhaust surface 501 is blocked by the above-mentioned wall 506 which is higher than the first exhaust surface 501, if the height of the wall 506 does not reach the upper end of the above-mentioned second exhaust surface 502, heat can be exhausted from the open space 701 of the recessed portion 601 that is not blocked by the above-mentioned wall 506. In this example, the height of the upper surface of the wall 506 is approximately at the center of the recess 601 provided on the back surface of the device body 10. Even when heat is exhausted from the duct 137 or fan 136, which are located at a lower position than the center, heat from inside the device can escape from the opening space 701 at a position higher than the center that is not covered by the wall 506 within the recess 601.

[0038] Furthermore, as shown in Figure 8, consider a configuration in which an outer cover 510 is attached to the main body 10 of the device, and the airflow of heat discharged from the duct 137 and fan 136 flows to the upper side of the main body 10. In this case, a filter 509 is detachably placed at the opening on the upper side of the main body 10, which is the downstream side of the airflow, to filter the airflow containing fine particles and dust discharged along with the exhausted heat. This makes it possible to remove the filter 509 from the front side opposite to direction A shown in Figure 1, in direction C, thereby improving the replaceability of the filter.

[0039] As described above, the image forming apparatus in this embodiment is an image forming apparatus 1 (or apparatus body 10) having an exhaust section (e.g., fan 136, duct 137) for exhausting heat from inside the apparatus. The exhaust section is provided on the side of the image forming apparatus and has a notched recess (e.g., the part of the notched shape 138) that opens above the position from which the heat is exhausted from the side (e.g., the position of surface A shown in Figure 4). With this configuration, heat from inside the apparatus can be released considering the thermal characteristics and the heat can be exhausted efficiently.

[0040] Furthermore, the recessed portion includes a first exhaust surface (e.g., a first exhaust surface 501) positioned horizontally at the same or near the lower end of the exhaust section, and a second exhaust surface (e.g., a second exhaust surface 502) extending upward from both sides in the width direction of the first exhaust surface, guiding the hot airflow exhausted from the exhaust section to the area above the first exhaust surface. With this configuration, the hot airflow exhausted from the fan 136 can be guided upward without being dispersed.

[0041] Furthermore, the upper opening that forms the notch shape has a portion (for example, the portion 602 shown in Figure 6) that protrudes outward from the bottom surface of the recess (for example, the bottom surface 503 of the recess shown in Figure 6), thereby forming the recess as a depression (for example, the depression 601 shown in Figure 6). With this configuration, even if there is a low wall (for example, wall 506) that covers part of the opening on the side of the device, heat can be exhausted from the space that is not covered by the opening (for example, the opening space 701). Furthermore, a filter (for example, filter 509) for filtering the exhausted hot airflow is detachably provided in the upper opening that forms the notch shape described above. With this configuration, the user can easily replace the filter from the front without having to go around to the rear of the device.

[0042] Furthermore, the recessed portion and the wall in contact with the surface of the image forming apparatus on the recessed portion side (for example, wall B shown in Figure 5) form a duct shape that guides the airflow of heat exhausted from the exhaust section. With this configuration, heat inside the apparatus can be released considering its thermal properties, and heat can be exhausted more efficiently.

[0043] Furthermore, the duct shape is formed with a first exhaust surface (for example, a first exhaust surface 501) positioned horizontally at the same or near the lower end of the exhaust section, and a second exhaust surface (for example, a second exhaust surface 502) extending upward from both sides in the width direction of the first exhaust surface, guiding the hot airflow exhausted from the exhaust section to the area above the first exhaust surface. With this configuration, the hot airflow exhausted from the fan 136 can be guided upward more reliably without being dispersed.

[0044] Conventionally, in technologies such as those described in Patent Document 1, an intake opening was formed between the lower surface of a slide tray that assists in loading sheets from the output tray and the slide opening, and the slide opening also served as the intake opening, resulting in a compact design. However, this configuration had the problem that the intake opening would be blocked if the image forming apparatus was installed flush against (or very close to) a wall. However, in the image forming apparatus with a recess in this embodiment, the exhaust port is positioned so as not to be blocked even when in close contact with a wall, and a recess is formed on the surface on the outside of the image forming apparatus extending from the exhaust port toward the upper surface of the image forming apparatus, thereby reducing the deterioration of exhaust efficiency caused by the intake opening being blocked. [Explanation of Symbols]

[0045] 1. Color copier 2 Image reading unit 3 Image forming unit 4 Paper feed section 5. Paper output section 6. Paper transport path 10 Main unit of the device 136 Fans 137 Duct 138 Notch Shape 501 First exhaust surface 502 Second exhaust surface 509 Filter 601 Recess [Prior art documents] [Patent Documents]

[0046] [Patent Document 1] Patent No. 3923709 specification

Claims

1. An image forming apparatus having an exhaust unit for exhausting heat from inside the apparatus, The exhaust unit is provided on the side of the image forming apparatus, A notched recessed portion with an opening above the position where the heat is exhausted from the side, It has, An image forming apparatus characterized in that the upper opening that forms the notch shape has a portion that protrudes from the bottom surface of the recess to the outside of the apparatus, thereby forming the recess as a depression.

2. The aforementioned recessed portion is, A first exhaust surface is positioned at the same horizontal position as or near the lower end of the exhaust section, A second exhaust surface extends upward from both sides in the width direction of the first exhaust surface and guides the hot airflow exhausted from the exhaust section to the upper part of the first exhaust surface, The image forming apparatus according to claim 1, characterized by having the following features.

3. The recessed portion and the wall in contact with the surface of the image forming apparatus on the recessed portion side form a duct shape that guides the airflow of heat exhausted from the exhaust portion. The image forming apparatus according to feature 1.

4. The aforementioned duct shape is, The exhaust section is formed having a first exhaust surface positioned horizontally at the same or near the lower end position as the lower end of the exhaust section, and a second exhaust surface extending upward from both sides in the width direction of the first exhaust surface, which guides the hot airflow exhausted from the exhaust section to the upper part of the first exhaust surface. The image forming apparatus according to feature 3.

Images