JP5595340B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming unit that performs image forming processing on a sheet, and more particularly, to an image forming apparatus including a duct for exhaust heat.

  The image forming apparatus includes various components and members that serve as heat sources and various devices including them. For example, there are a power supply board on which power semiconductor elements and the like are mounted, and a fixing device that performs a fixing process on a sheet on which a toner image is transferred. In order to discharge the heat generated by these heat source apparatuses to the outside of the apparatus, the image forming apparatus is provided with a duct for exhaust heat.

  Generally, a fan is attached to the end of the duct in order to promote exhaust heat. An air flow is generated in the duct by the operation of the fan, and warm air in the machine is discharged outside the machine by the air flow. Patent Document 1 discloses an image forming apparatus in which exhaust efficiency is improved by arranging ducts in a vertical direction in an apparatus main body, and by an ascending airflow due to a so-called chimney effect and an airflow due to an intake operation of the fan. Is disclosed.

JP 2004-287216 A

  In the prior art, it is assumed that a fan that forcibly generates an exhaust air flow is applied to the exhaust heat duct. However, using a fan leads to power consumption, which is not desirable for energy saving effect. Further, since the driving sound is inevitably generated by the operation of the fan, it is not preferable when the image forming apparatus is arranged in a quiet environment.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can perform a heat exhausting operation without using a fan as much as possible.

  An image forming apparatus according to an aspect of the present invention includes a main body housing that houses an image forming portion that performs image forming processing on a sheet, a heat source device that is attached to the main body housing and generates heat, and the main body A duct attached to the housing and having a lower end opening and an upper end opening and extending in the longitudinal direction, and the heat source device is attached to the main body housing so as to heat the air in the duct. .

  According to this configuration, the air in the duct extending in the longitudinal direction is positively heated by the heat generated by the heat source device. Therefore, a relatively large ascending air current is generated in the duct, and the so-called chimney effect is promoted. With such a chimney effect, it is possible to take in warm air from the lower end side opening and exhaust it from the upper end side opening without using the suction force or blowing force of the fan.

  The said structure WHEREIN: It is desirable to mount | wear with the at least one part of the said heat-source apparatus exposed in the inside of the said duct. According to this configuration, the air in the duct can be efficiently heated by a part of the heat source device exposed inside the duct.

  The said structure WHEREIN: It is desirable to mount | wear with the said heat-source apparatus so that it may be located in the vicinity of the lower end side opening of the said duct. According to this configuration, the air heated by the heat generated by the heat source device naturally enters the duct from the lower end side opening, and as a result, the air in the duct can be heated.

  In the above configuration, it is one of the preferred embodiments that the heat source device is a substrate on which a heat-generating electric element is mounted. A substrate on which an exothermic electrical element is mounted is one of the devices that generate the largest heat in an image forming apparatus. By using this substrate for heating the air in the duct, the chimney effect can be enhanced, and the heat generated by itself can be directly discharged through the duct.

  In this case, an exterior member that covers the main body casing is further provided, the main body casing includes a side plate that defines a storage space for storing the image forming unit, and the substrate and the duct are arranged on an outer side surface of the side plate ( It is desirable that an exhaust port that is disposed between the rear frame surface) and the inner surface of the exterior member and communicates with the upper end side opening of the duct is provided on the upper end side of the exterior member.

  According to this configuration, the side plate functions as a kind of heat sink that absorbs the heat in the housing space, and the warm air generated between the outer side surface of the side plate and the inner side surface of the exterior member is generated by the duct and the exhaust port. Can be discharged to the outside. And since the air in a duct is heated with the heat | fever which a board | substrate emits, the said warm air can be discharged | emitted efficiently by a chimney effect.

  In the above configuration, the duct includes a bottom plate extending in a vertical direction in parallel with the side plate, the substrate is fitted into an opening provided in the bottom plate, and the electric element protrudes into the duct, It is desirable to be attached to the side plate. According to this configuration, it is possible to easily perform the assembly of the substrate to the duct, that is, the assembly in a mode in which the air in the duct can be heated.

  The duct includes a bottom plate extending in the vertical direction in parallel with the side plate, the bottom plate is attached to the side plate at a predetermined interval, and the substrate is spaced at substantially the same interval as the predetermined interval. It is desirable to be attached to the side plate below the lower end side opening. According to this configuration, heat generated from the substrate can be efficiently taken into the duct.

  According to the present invention, in the image forming apparatus, the heat in the main body casing can be efficiently discharged outside the apparatus using the chimney effect. As a result, it is possible to reduce the necessity of attaching a fan to the exhaust heat duct to generate a forced air flow. Accordingly, it is not necessary to install a fan for exhaust heat in the image forming apparatus, or it is sufficient to apply a fan with a small capacity, and an energy saving effect and a noise reduction effect can be obtained.

1 is a perspective view of an image forming apparatus according to an embodiment of the present invention as viewed from the left front side. It is the perspective view which looked at the above-mentioned image forming device from diagonally right back. It is sectional drawing which shows the internal structure of the said image forming apparatus. It is a perspective view which shows the back frame of a main body frame. It is a perspective view which shows the state in which the board | substrate was attached to the said back frame. It is a perspective view showing the state where a part of duct concerning a 1st embodiment was attached to the back frame. It is a perspective view which shows the state by which the duct which concerns on 1st Embodiment was attached to the said back frame. It is a perspective view which shows the state by which the rear exterior board was attached on the said back frame. It is a longitudinal cross-sectional view of the apparatus main body in the attachment part of the duct which concerns on 1st Embodiment. It is a perspective view showing the state where a part of duct concerning a 2nd embodiment was attached to the back frame. It is a perspective view which shows the state by which the duct which concerns on 2nd Embodiment was attached to the said back frame. In FIG. 10, it is a perspective view which shows the state by which the upper exterior board was further attached to the upper end of the said back frame. In FIG. 11, it is a perspective view which shows the state by which the upper exterior board was further attached to the upper end of the said back frame. It is a longitudinal cross-sectional view of the apparatus main body in the attachment part of the duct which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 are perspective views showing an external appearance of an image forming apparatus 1 according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing an internal structure of the image forming apparatus 1. Here, the image forming apparatus 1 exemplifies a so-called in-body discharge type copier, but the image forming apparatus may be a printer, a facsimile machine, or a multifunction machine having these functions.

  The image forming apparatus 1 includes an apparatus main body 2 having a substantially rectangular parallelepiped housing structure and having an in-cylinder space (in-cylinder discharge unit 24). The apparatus main body 2 performs an image forming process on the sheet. The apparatus main body 2 includes a substantially rectangular parallelepiped lower casing 21, a substantially rectangular parallelepiped upper casing 22 disposed above the lower casing 21, and a connection that connects the lower casing 21 and the upper casing 22. And a housing 23. The lower housing 21 accommodates various devices for image formation, and the upper housing 22 accommodates various devices for optically reading a document image. An in-cylinder space surrounded by the lower casing 21, the upper casing 22, and the connecting casing 23 serves as an in-cylinder discharge unit 24 that can store a sheet after image formation. The connection housing 23 is disposed on the right side surface 2 </ b> R of the apparatus main body 2, and is provided with a discharge port 961 for discharging the sheet to the in-body discharge unit 24.

  The in-cylinder space used as the in-cylinder sheet discharge unit 24 is open to the outside on the front surface and the left side surface of the apparatus main body 2. The user can insert a hand from these open portions and take out the sheet after image formation from the in-body sheet discharge unit 24. A bottom surface 241 of the in-cylinder space is partitioned by the upper surface of the lower housing 21 and a sheet discharged from the discharge port 961 is stacked thereon.

  The lower casing 21 is equipped with a paper feed cassette 211 that accommodates sheets to be subjected to image forming processing. The paper feed cassette 211 can be pulled out from the front surface 2F of the lower housing 21 (apparatus body 2). The paper feeding cassette 211 is a cassette provided for automatic paper feeding.

  A multi-tray unit M is mounted on the right side surface 2R of the apparatus main body 2 for allowing the user to manually feed paper. The multi-tray unit M includes a paper feed tray 213 on which a manual sheet is placed, and a paper feed unit 214 that carries the manual sheet into an image forming unit in the lower housing 21. The paper feed tray 213 is attached to the lower housing 21 at its lower end so as to be openable and closable, and is closed when not in use. When the user performs manual sheet feeding, the user opens the sheet feeding tray 213 and places a sheet thereon.

  As shown in FIG. 2, a rear side exterior member 201 is attached to the rear surface 2 </ b> B of the apparatus main body 2. Inside the exterior member 201, a duct 50 for exhaust heat extending in the vertical direction (vertical direction) is disposed. In the vicinity of the upper end of the exterior member 201, an exhaust port 202 for exhausting air (warm air) exhausted from the duct 50 to the outside is perforated. The duct 50 and its peripheral structure will be described in detail later.

  An operation panel unit 25 protrudes from the front surface of the upper housing 22. The operation panel unit 25 includes a numeric keypad, a start key and the like in addition to the LCD touch panel 251, and accepts input of various operation instructions from the user. The user can input the number of sheets to be printed and the like and input the print density and the like through the operation panel unit 25.

  An ADF (Automatic Document Feeder) device 3 that automatically supplies a document on which an image is read to a predetermined document reading position (first contact glass 222) is attached on the upper housing 22 (not shown in FIG. 3). ) The ADF device 3 is rotatably attached to the upper housing 22 at the rear edge thereof, and transports the document tray 31 on which a document to be read is placed, and transports the document via the document reading position. And a document discharge tray 33 from which the document after reading is discharged.

  Next, the internal structure of the apparatus main body 2 will be described with reference to FIG. In the lower casing 21, toner containers 99Y, 99M, 99C, and 99Bk, an intermediate transfer unit 92, an image forming unit 93, an exposure unit 94, and the above-described paper feed cassette 211 are accommodated in this order from the top.

  The image forming unit 93 forms four image forming units 10Y and 10M that form yellow (Y), magenta (M), cyan (C), and black (Bk) toner images in order to form a full-color toner image. 10C, 10Bk. Each of the image forming units 10Y, 10M, 10C, and 10Bk includes a photosensitive drum 11 and a charger 12, a developing device 13, a primary transfer roller 14, and a cleaning device 15 that are disposed around the photosensitive drum 11. .

  The photosensitive drum 11 rotates about its axis, and an electrostatic latent image and a toner image are formed on its peripheral surface. As the photoreceptor drum 11, a photoreceptor drum using an amorphous silicon (a-Si) material can be used. The charger 12 uniformly charges the surface of the photosensitive drum 11. The peripheral surface of the photosensitive drum 11 after charging is exposed by the exposure unit 94 to form an electrostatic latent image.

  The developing device 13 supplies toner to the peripheral surface of the photosensitive drum 11 in order to develop the electrostatic latent image formed on the photosensitive drum 11. The developing device 13 is for a two-component developer and includes stirring rollers 16 and 17, a magnetic roller 18, and a developing roller 19. The stirring rollers 16 and 17 charge the toner by circulating and conveying the two-component developer while stirring. A two-component developer layer is carried on the peripheral surface of the magnetic roller 18, and toner formed by transferring toner to the peripheral surface of the developing roller 19 due to a potential difference between the magnetic roller 18 and the developing roller 19. The layer is supported. The toner on the developing roller 19 is supplied to the peripheral surface of the photosensitive drum 11 and the electrostatic latent image is developed.

  The primary transfer roller 14 forms a nip portion with the photosensitive drum 11 across the intermediate transfer belt 921 provided in the intermediate transfer unit 92, and the toner image on the photosensitive drum 11 is primary transferred onto the intermediate transfer belt 921. To do. The cleaning device 15 cleans the peripheral surface of the photosensitive drum 11 after the toner image is transferred.

  The yellow toner container 99Y, the magenta toner container 99M, the cyan toner container 99C, and the black toner container 99Bk each store toner of each color, and image forming units 10Y, 10M, and 10C corresponding to the respective colors of YMCBk. Each color toner is supplied to the 10 Bk developing device 13 through a supply path (not shown).

  The exposure unit 94 includes various optical system devices such as a light source, a polygon mirror, a reflection mirror, and a deflection mirror, and is provided on the peripheral surface of the photosensitive drum 11 provided in each of the image forming units 10Y, 10M, 10C, and 10Bk. The electrostatic latent image is formed by irradiating light based on the image data of the document image.

  The intermediate transfer unit 92 includes an intermediate transfer belt 921, a driving roller 922, and a driven roller 923. On the intermediate transfer belt 921, toner images are overcoated from the plurality of photosensitive drums 11 (primary transfer). The overcoated toner image is secondarily transferred by the secondary transfer unit 98 onto a sheet supplied from the paper feed cassette 211 or the paper feed tray 213.

  The paper feed cassette 211 stores a sheet bundle in which a plurality of sheets are stacked. A pickup roller 212 is disposed on the upper right side of the paper feed cassette 211. By driving the pickup roller 212, the uppermost sheet of the sheet bundle in the sheet feeding cassette 211 is fed out one by one and carried into the carry-in conveyance path 26. On the other hand, the sheet placed on the paper feed tray 213 is carried into the carry-in conveyance path 26 by driving the paper feed roller 215 of the paper feed unit 214.

  On the downstream side of the carry-in conveyance path 26, a sheet conveyance path 28 that extends to the discharge port 961 through the secondary transfer unit 98, a fixing unit 97 and a paper discharge unit 96 described later is provided. The upstream portion of the sheet conveyance path 28 is formed between an inner wall formed in the lower housing 21 and an inner wall that forms the inner surface of the reverse conveyance unit 29. The outer surface of the reverse conveyance unit 29 constitutes one side of a reverse conveyance path 291 that reversely conveys the sheet during duplex printing. A registration roller pair 27 is disposed on the upstream side of the sheet transfer path 28 from the secondary transfer unit 98. The sheet is temporarily stopped by the registration roller pair 27, and after skew correction is performed, the sheet is sent to the secondary transfer unit 98 at a predetermined timing for image transfer.

  A fixing unit 97 and a paper discharge unit 96 are accommodated in the connection housing 23. The fixing unit 97 includes a fixing roller and a pressure roller, and performs a fixing process by heating and pressing the sheet on which the toner image is secondarily transferred in the secondary transfer unit 98. The sheet with the color image that has been subjected to the fixing process is discharged from the discharge port 961 toward the in-body discharge unit 24 by the discharge unit 96 disposed downstream of the fixing unit 97.

  A first contact glass 222 and a second contact glass 223 are fitted on the upper surface of the upper housing 22. The first contact glass 222 is provided for reading a document sheet automatically fed from the ADF apparatus 3. The second contact glass 223 is provided for reading a manually placed document sheet.

  Inside the upper housing 22, a scanning mechanism 224 and an image sensor 225 for optically reading document information are accommodated. The scanning mechanism 224 includes a light source, a moving carriage, a reflection mirror, and the like, and guides reflected light from the document to the image sensor 225. The image sensor 225 photoelectrically converts the reflected light into an analog electrical signal. The analog electric signal is converted into a digital electric signal by an A / D conversion circuit (not shown) and then input to the exposure unit 94.

[First Embodiment of Duct]
Then, the duct 50 which concerns on 1st Embodiment is demonstrated based on FIGS. FIG. 4 is a perspective view of a main body frame 40 (main body housing) that is located inside the exterior member that forms the outer surface of the apparatus main body 2 and that forms the housing structure, as viewed from the rear. Here, the state before the 1st board | substrate P1 and 2nd board | substrate P2 (heat source apparatus) and the duct 50 which are mentioned later are mounted | worn is shown.

  The main body frame 40 includes a flat front frame (not shown) and a rear frame 41 (side plates) arranged at a predetermined interval, an upper frame 42 arranged on both the frames, and a space between the two frames. The top frame 431, the middle frame 432, and the bottom frame 433 are installed horizontally. The peripheral surface of the main body frame 40 is covered with an exterior member, and the rear frame 41 is covered with a rear surface side exterior member 201 shown in FIG.

  In the accommodation space between the front frame and the rear frame 41, the toner containers 99Y, 99M, 99C, 99Bk, the intermediate transfer unit 92, the image forming unit 93, the exposure unit 94, the paper feed cassette 211, and the like are accommodated. The The upper frame 42 corresponds to the upper housing 22 described above, and houses the scanning mechanism 224 and the image sensor 225 and holds the first contact glass 222 and the second contact glass 223 on the upper surface thereof.

  The rear frame 41 is provided with a first support piece 411 and a second support piece 412 that are formed by vertically raising a part of the rear frame 41. The first support piece 411 protrudes above the rear frame 41, and the second support piece 412 protrudes substantially directly below the first support piece 411. Each of the first and second support pieces 411 and 412 includes four cut-and-raised pieces positioned at respective vertices of a rectangle that is long in the vertical direction, and the tip of each cut-and-raised piece is a plane parallel to the rear frame 41. The bent surface is bent vertically.

  FIG. 5 is a perspective view showing a state where the first substrate P1 and the second substrate P2 are attached to the first support piece 411 and the second support piece 412, respectively. The first and second substrates P1 and P2 are rectangular circuit boards on which heat-generating electrical elements such as power semiconductor modules and power supply elements are mounted on the surface side. These first and second substrates P1 and P2 are energized and generate heat when the image forming apparatus 1 is in operation. The first and second substrates P <b> 1 and P <b> 2 are arranged so that the longitudinal direction is along the vertical direction, and are supported and fixed by the first support piece 411 and the second support piece 412 at the four corners on the back surface side, respectively.

  6 and 7 are perspective views showing a state in which the duct 50 according to the first embodiment is attached to the rear frame 41. The duct 50 is a rectangular duct that is long in the vertical direction and has a horizontal cross section that is elongated in the left-right direction, and is an assembly of a channel member 51 having a U-shaped cross section and a cover plate 52 that covers the opening of the channel member 51. Consists of the body.

  As shown in FIG. 6, the channel member 51 stands from the bottom plate 511 extending in the vertical direction in parallel with the rear frame 41, the opening 512 drilled in the middle in the vertical direction of the bottom plate 511, and the left and right edges of the bottom plate 511. And a side plate 513 provided. The opening 512 is a rectangular opening that is long in the vertical direction, and has a size slightly larger than the outer size of the first substrate P1. Referring also to FIG. 9, the upper end portion of the channel member 51 is a curved surface 514 in which an upward bottom plate 511 is bent 90 ° rearward, and a tip edge thereof slightly protrudes rearward from a tip edge of the side plate 513. ing. Corresponding to the curved surface 514, an extension 515 that slightly protrudes backward is provided at the upper end of the side plate 513. The lower end 516 of the channel member 51 is adjacent to the upper end of the second substrate P2.

  The lid plate 52 is a rectangular flat plate, and is spanned between the front edges of the pair of side plates 513. The length in the vertical direction of the cover plate 52 is substantially the same as the length excluding the curved surface 514 of the channel member 51, and a bent portion 521 that is bent vertically toward the rear is formed at the upper end portion thereof. The protruding length of the bent portion 521 is the same as the protruding length of the extension portion 515. The cover plate 52 is attached so as to cover the opening of the channel member 51 so that the bent portion 521 extends along the lower edge of the extended portion 515. Thereby, the duct 50 provided with the circulation space D (refer FIG. 9) of air is formed.

  A lower end side opening 53 of the duct 50 serves as an air inlet opening, and an upper end side opening 54 serves as an air outlet opening. The lower end side opening 53 is an opening parallel to the installation surface of the image forming apparatus 1, whereas the circulation space D is bent by 90 ° by the curved surface 514, so that the upper end side opening 54 is an opening orthogonal to the installation surface. It has become.

  The bottom plate 511 of the channel member 51 is also supported by the first support piece 411 at a predetermined interval with respect to the rear frame 41. As shown in FIG. 9, the first substrate P1 includes a flat wiring board 61 and an electric element 62 mounted on the wiring board. The wiring board 61 is fitted into the opening 512, and is supported by the first support piece 411 with a distance substantially the same as that of the bottom plate 511 with respect to the rear frame 41. On the other hand, the electric element 62 is exposed in the circulation space D of the duct 50. Therefore, the air in the circulation space D of the duct 50 is heated by the heat generated by the electric element 62.

  Similarly, the second substrate P2 includes a flat wiring board 63 and an electric element 64 mounted on the wiring board. The second substrate P <b> 2 is disposed immediately below the lower end side opening 53, and the wiring board 63 is spaced from the rear frame 41 by substantially the same distance as the bottom plate 511 of the channel member 51 has the rear frame 41. It is supported by the second support piece 412. Therefore, the air heated by the heat generated by the electric element 64 flows into the circulation space D of the duct 50 through the lower end opening 53, and as a result, the air in the circulation space D is heated.

  As shown in FIG. 8, when the assembly of the first and second substrates P1, P2 and the duct 50 to the rear frame 41 is completed, the rear side exterior member 201 (see also FIG. 2) is attached thereon. . That is, the first and second substrates P <b> 1 and P <b> 2 and the duct 50 are disposed between the outer side surface of the rear frame 41 and the inner side surface of the rear side exterior member 201. The exhaust port 202 near the upper end of the exterior member 201 faces the upper end side opening 54 of the duct 50.

  According to the image forming apparatus 1 having the above configuration, the air in the duct 50 extending in the vertical direction is positively heated by the heat generated by the first and second substrates P1 and P2. In particular, in the first substrate P1, the electric element 62, which is a heat source, is exposed in the circulation space D and directly heats the air in the duct 50. The second substrate P <b> 2 is disposed immediately below the lower end side opening 53, so that the air heated by the electric element 64 is easily introduced into the duct 50.

  Here, since the duct 50 is a duct extending in the vertical direction, when warm air in the apparatus main body 2 enters the duct 50, an air flow from the lower end side opening 53 toward the upper end side opening 54 is generated by a so-called chimney effect. In addition, when the first and second substrates P1 and P2 generate heat and heat the air in the duct 50, a large upward airflow is generated in the duct 50, and the chimney effect is promoted. . That is, the heated air in the duct 50 is discharged outside the machine through the upper end side opening 54 and the exhaust port 202 by the rising airflow, while the air in the vicinity of the lower end side opening 53 that has become negative pressure due to the discharge enters the duct 50. Will be introduced. And since the 1st, 2nd board | substrates P1 and P2 continue supplying heat to the distribution space D of the duct 50, an upward airflow is always produced | generated in the distribution space D. FIG. By such a chimney effect, it is possible to take in warm air from the lower end side opening 53 and exhaust it from the upper end side opening 54 without using the suction force or blowing force of the fan.

[Second Embodiment of Duct]
Next, the duct 50A according to the second embodiment will be described with reference to FIGS. The duct 50A is a straight-advancing duct that does not have the curved surface 514 like the duct 50 of the first embodiment. The duct 50 </ b> A is a rectangular duct that is long in the vertical direction and has a horizontal cross-section that is long in the left-right direction. Consists of the body. FIG. 10 is a perspective view showing a state in which the channel member 55 is attached to the rear frame 41, and FIG. 11 is a perspective view showing a state in which the duct 50A is attached to the rear frame 41.

  The channel member 55 includes a bottom plate 551 extending in the vertical direction parallel to the rear frame 41, an opening 552 drilled in the middle of the bottom plate 551 in the vertical direction, and a side plate 553 erected from the left and right edges of the bottom plate 551. Including. The bottom plate 551 is a flat plate that extends straight from the upper end 554 to the lower end 555, the upper end 554 extends to the upper end of the main body frame 40, and the lower end 555 is adjacent to the upper end of the second substrate P2. The first substrate P1 is fitted into the opening 552.

  The lid plate 56 is a rectangular flat plate, and is spanned between the leading edges of the pair of side plates 553. The length of the lid plate 56 in the vertical direction is substantially the same as the length of the channel member 55 in the vertical direction. By attaching the cover plate 56 to the channel member 55, a duct 50A having an air circulation space D (see FIG. 14) is formed. The lower end side opening 57 of the duct 50 </ b> A serves as an air inlet opening, and the upper end side opening 58 serves as an air outlet opening. In addition, about the support structure by the 1st support piece 411 and the 2nd support piece 412, it is the same as that of 1st Embodiment.

  12 is a perspective view showing a state in which the upper exterior plate 203 is attached to the upper end of the rear frame 41 in FIG. 10, and FIG. 13 is a perspective view showing a state in which the upper exterior plate 203 is attached in FIG. An exhaust port 204 is formed in the upper exterior plate 203 at a position facing the upper end side opening 58 of the duct 50A.

  Also with such a duct 50A according to the second embodiment, the warm air in the apparatus main body 2 can be discharged outside the apparatus by using the chimney effect described in the first embodiment without using a fan or the like. That is, when the first and second substrates P1 and P2 generate heat and heat the air in the duct 50A, a large upward airflow is generated in the duct 50A and is introduced from the lower end opening 57. Air is discharged from the upper surface of the apparatus body 2 to the outside through the upper end side opening 58 and the exhaust port 204.

  According to the present invention described above, in the image forming apparatus 1, the heat in the main body casing is positively heated by the first and second substrates P1 and P2 using the air in the ducts 50 and 50A as a heat source. The effect can be promoted and warm air can be efficiently discharged outside the machine. In addition, the heat generated by the first and second substrates P1 and P2 can be efficiently discharged outside the apparatus. As a result, it is possible to reduce the necessity of attaching a fan to the exhaust heat duct to generate a forced air flow. Accordingly, it is possible to omit the installation of a fan for exhausting heat from the image forming apparatus 1, or even if a fan is necessary, it is sufficient to use a small capacity fan. Can be obtained.

  The first and second substrates P1, P2 and the ducts 50, 50A are disposed between the outer surface of the rear frame 41 and the inner surface of the exterior member 201, and the ducts 50, 50A are disposed on the upper end side of the exterior member 201. Exhaust ports 202 and 204 communicating with the upper end side opening are provided. Therefore, the rear frame 41 (the side plate of the main body frame) functions as a kind of heat sink that absorbs heat generated by devices disposed in the accommodation space between the front frame and the rear frame 41, and the rear generated thereby. Warm air between the frame 41 and the exterior member 201 can be discharged to the outside through the ducts 50 and 50A and the exhaust ports 202 and 204. In addition, since the air in the ducts 50 and 50A is heated by the heat generated by the first and second substrates P1 and P2, the warm air can be efficiently discharged by the chimney effect.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to this, For example, the following modified embodiment can be taken.

  (1) In the said embodiment, 1st, 2nd board | substrates P1 and P2 were illustrated as a heat source apparatus which heats the air in a duct. Instead of this, a component that is normally mounted on the image forming apparatus 1 that generates heat, such as a drive motor, may be used as a heating source. Alternatively, heat exchange may be performed between the exhaust heat piping of the fixing unit 97 and the air in the distribution space D of the ducts 50 and 50A.

  (2) In the above embodiment, an example in which the first substrate P1 is disposed inside the ducts 50 and 50A and the second substrate P2 is disposed directly below the ducts 50 and 50A has been described. Instead of this, both the first and second substrates P1 and P2 may be disposed inside the ducts 50 and 50A, or may be disposed directly below the ducts 50 and 50A. Alternatively, a plurality of vertical ducts may be arranged in a dual manner, and the heat source device (substrate) may be arranged inside or directly below each duct.

  (3) In the above embodiment, the example in which the electric element 62 of the first substrate P1 is exposed in the circulation space D is shown. Instead of this, a heat sink may be protruded from the back surface side of the wiring board 61 of the first substrate P1, and the heat sink instead of the electric element 62 may be exposed in the circulation space D.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Apparatus main body 40 Main body frame (main body housing)
41 Rear frame (side plate)
50, 50A Duct 51, 55 Channel member 511, 551 Bottom plate 52 Lid plate 53, 57 Lower end opening 54, 58 Upper end opening 61, 63 Wiring board 62, 64 Electrical element 93 Image forming unit P1 First substrate (heat source device)
P2 Second substrate (heat source device)

Claims (3)

A main body housing that houses an image forming unit that performs image forming processing on the sheet;
A substrate mounted on the main body housing and mounted with a heat-generating electrical element ;
A duct attached to the main body housing, having a lower end side opening and an upper end side opening and extending in a vertical direction;
An exterior member covering the main body casing ,
The substrate, at least a portion of the substrate, by being mounted in a state that is exposed to the inside of the duct, there is attached the air in the duct heatable said body housing,
The main body casing includes a side plate that defines a storage space for storing the image forming unit,
The substrate and the duct are disposed between an outer surface of the side plate and an inner surface of the exterior member,
An exhaust port communicating with the upper end side opening of the duct is provided on the upper end side of the exterior member,
The duct includes a bottom plate extending in the vertical direction in parallel with the side plate,
The image forming apparatus , wherein the substrate is fitted into an opening provided in the bottom plate, and is attached to the side plate in a state where the electric element protrudes into the duct . The image forming apparatus according to claim 1 .
An image forming apparatus , further comprising another substrate mounted so as to be positioned in the vicinity of the lower end side opening of the duct and mounted with a heat-generating electric element . The image forming apparatus according to claim 2 .
The bottom plate is attached to the side plate at a predetermined interval,
The image forming apparatus, wherein the other substrate is attached to the side plate below the lower end side opening at substantially the same interval as the predetermined interval.

Images