JP2006098643A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive image forming apparatus in which effect on toner in a rotary developing device is reduced and the formation of a highly reliable and high quality image is ensured by sharing a member disposed near the rotary developing device without disposing a dedicated member used for intercepting heat emitted to the rotary developing device from its surroundings. <P>SOLUTION: An exhaust duct 30 in which its suction port 31 is disposed near and above a developing position where the developing roller 14c of the rotary developing device 14 faces a photoreceptor drum 12 is provided in a connected row arrangement to an exhaust port 33 disposed on the lower part of the device by way of a detour so that an exhaust path 32 is formed to cover from the upper part to the inside of the external cover 20 of the side so as to cover the external face of the rotary developing device 14. The exhaust duct 30 prevents generation of heat from a power source substrate 50 from affecting toner stored in the developing cartridge 14a of the rotary developing device 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to an apparatus capable of reducing noise generated during an image forming operation.

  2. Description of the Related Art Conventionally, an electrophotographic recording type image forming apparatus that exposes and forms an electrostatic latent image on the surface of a carrier made of a photoreceptor is known. In this image forming apparatus, the electrostatic latent image is developed with toner. The toner image on the surface of the carrier carried in this manner is transferred to a recording medium such as recording paper to form an image. This electrostatic latent image can be developed with toner by rotating the developing roller facing the surface of the carrier to transfer the toner on the circumferential surface of the roller to adhere it.

  An image forming apparatus that employs this electrophotographic recording system includes a developing roller that stores toner in a container together with a developing roller that faces a carrier, and a device that includes a rotary developing device that can store a plurality of the developing cartridges. There is also. In this image forming apparatus, the developing cartridge at the developing position facing the carrier can be switched by rotating the rotary developing device about the rotation axis.

In such an image forming apparatus, as a developing cartridge that attaches toner to the surface of a carrier, a developing cartridge that contains yellow (Y), magenta (M), cyan (C), and black (K) toners is rotary developed. By being configured so as to be housed (installable) in the apparatus, it is possible to form a color image in which each color is superimposed by sequentially switching the developing cartridges, and a single color image with one color toner, for example, black (K) toner It is also possible to form a black-and-white monochrome image (hereinafter also simply referred to as a monochrome image) by (see, for example, Patent Document 1).
JP 2003-295714 A

  However, in an image forming apparatus provided with such a rotary developing device, the toner contained in the developing cartridge is greatly affected by the environment. For example, when the ambient temperature becomes high, there is a possibility that the quality of the toner may be problematic.

  On the other hand, in recent years, such an OA device is particularly required to be miniaturized, and the accommodating space in the apparatus is also narrowed. Therefore, the rotary developing device that accommodates the developing cartridge is close to the heating element. It becomes difficult to avoid becoming a layout.

  Here, in the image forming apparatus provided with such a rotary developing device, the toner is developed while rotating both the carrier and the developing roller, so that all of the toner on the peripheral surface of the developing roller is transferred to the carrier. It is difficult to make them collect in the developing cartridge. For this reason, since the toner is a fine powder, it may be scattered and accumulated around the developing position facing the carrier, and the recording paper may be soiled. For this reason, it has been proposed that an image forming apparatus employing an electrophotographic recording system is provided with an exhaust duct that sucks and exhausts the vicinity of the developing position (see, for example, the above-mentioned document 1).

  Accordingly, the present invention eliminates the need for a dedicated member that blocks heat from the surroundings applied to the rotary developing device, and diverts a member disposed near the rotary developing device, so that An object of the present invention is to provide an inexpensive image forming apparatus that can form a high-quality image with high reliability while reducing the influence on toner.

  An image forming apparatus according to a first aspect of the present invention for solving the above-described problems includes a carrier for carrying a toner image in which an electrostatic latent image is formed on the surface and developing the electrostatic latent image, and an electrostatic latent image on the surface of the carrier. A developing cartridge that develops by attaching toner to an image; and a rotary developing device that houses a plurality of developing cartridges around a rotation shaft and rotates about the rotation shaft, and is opposed to the surface of the carrier. An image forming apparatus that forms a desired image by switching a cartridge, and has an exhaust duct that sucks the vicinity of a developing position where toner is attached to a carrier and exhausts it outside the apparatus. A path is formed so as to hide the outer surface of the developing device from the heating element.

  In the present invention, the outer surface of the rotary developing device is covered with the exhaust duct so as to be hidden from the heating element. Therefore, the heat from the heating element is carried away by the exhaust duct before it reaches the developing cartridge in the rotary developing device, so that it is carried away by the exhaust flowing through the exhaust duct, and the toner in the developing cartridge is heated by the heating element. Is hardly affected by.

  According to a second invention of an image forming apparatus that solves the above problems, in addition to the specific matters of the first invention, the heating element forms an electrostatic latent image on a power supply base for supplying power to each part of the apparatus and a carrier. One or more of a scanner unit, a fixing unit for fixing toner formed on an image by heating and press-contacting a recording medium, and a driving motor for operating a driving mechanism are characterized.

  In the present invention, in the case of a layout in which a power supply substrate or the like that can be a heating element (heat source) is arranged around the rotary developing device, an exhaust duct path is set between them. Therefore, it is possible to freely lay out a power supply substrate or the like that can be a heat source without considering the influence on the toner in the developing cartridge.

  According to a third aspect of the image forming apparatus for solving the above problem, in addition to the specific matters of the first or second aspect, the exhaust duct includes at least a part or all of a member that defines a path on the heating element side. It is made of a material having excellent thermal conductivity.

  In the present invention, the side of the exhaust duct facing the heating element is excellent in thermal conductivity, for example, is made of metal, and the exhaust passage is defined. Therefore, it is possible to efficiently absorb the heat from the heating element and exchange heat with the exhaust, and to suppress the temperature rise of the heating element peripheral member such as the exhaust duct itself.

  According to a fourth invention of an image forming apparatus for solving the above-mentioned problems, in addition to the specific matters of any of the first to third inventions, the exhaust duct faces the outer peripheral surface on which the rotary developing device rotates. A pair of facing plates, and a rectifying plate that divides the exhaust flow path from the suction port side toward the exhaust port side between the facing plates into a plurality of parts and regulates the air flowing in the exhaust flow path. It is characterized by this.

  In the present invention, the exhaust in the exhaust duct can be divided and regulated to have a desired flow. Therefore, the exhaust can be efficiently performed, a heat accumulation is not formed in the exhaust path, and the temperature increase of the exhaust duct can be avoided.

  According to a fifth aspect of the image forming apparatus for solving the above-mentioned problems, in addition to the specific matters of the fourth aspect, the rectifying plate of the exhaust duct divides the exhaust passage so that suction can be performed substantially uniformly from a wide suction port. In addition, the exhaust passage is narrowed down toward the narrow exhaust port, and the exhaust passage is defined so that the passage spaces for the respective exhaust passages are substantially uniform.

  In the present invention, the air can be exhausted by being sucked evenly into the exhaust flow passages divided substantially equally. Therefore, exhaust can be performed without any difference between the flow paths, and no heat accumulation is formed in the exhaust path, so that the temperature of the exhaust duct can be prevented from rising.

  According to a sixth aspect of the image forming apparatus for solving the above-mentioned problems, in addition to the specific matter of the fourth or fifth aspect, the rectifying plate of the exhaust duct is an exhaust having a large bend between the suction port and the exhaust port. The flow path is set so as to increase the flow path space.

  In the present invention, the path with a large bending of the exhaust path in the exhaust duct has a large flow path space, and can be exhausted from the exhaust port through the flow path with little loss. Therefore, exhaust can be performed without any difference between the flow paths, and no heat accumulation is formed in the exhaust path, so that the temperature of the exhaust duct can be prevented from rising.

  As described above, according to the present invention, the exhaust duct covers the outer surface of the rotary developing device so as to hide it from the heating element. Therefore, before the heat from the heating element reaches the developing cartridge in the rotary developing device, the heat is exhausted to the exhaust duct. It can be carried away by the exhaust gas flowing inside, and the toner in the developing cartridge can be prevented from being affected by the heat of the heating element. Therefore, it is possible to form a high-quality image with high reliability by effectively reducing the influence of the heating element on the toner without taking up space or increasing the cost by dedicated heat insulation means. it can.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the drawings. 1 to 6 are views showing a first embodiment of an image forming apparatus according to the present invention.

  In FIG. 1, an image forming apparatus is a printer that is used by connecting to an external apparatus such as a personal computer that creates and outputs an image such as a character. The image forming apparatus is an image such as a character of a target image to be imaged. An image recording apparatus that receives data and records and forms the recording sheet P (recording medium) on one side or both sides of the recording sheet P (recording medium) by electrophotography, and transports a plurality of stacked recording sheets P to the image recording apparatus and records an image. And a sheet conveying device that unloads the formed recording sheet P and stacks it.

  The image recording apparatus will be briefly described. The laser beam scanning device (scanner unit) 11 that scans the laser beam L based on the image data, and the laser beam L from the laser beam scanning device 11 is irradiated and scanned. A photosensitive drum (carrier) 12 on which an electrostatic latent image based on image data of the image is exposed and formed on the surface, and an outer peripheral surface of the photosensitive drum 12 so that an electrostatic latent image can be formed by irradiation with laser light L. Each color for charging the electrostatic latent image on the photosensitive drum 12 by a developing unit containing a charging unit 13 for charging and yellow (Y), cyan (C), magenta (M), and black (K) toners. A developing cartridge 14a for each color, a rotary developing device 14 for operating the developing cartridge 14a in an installation space 14b for each color, and a target image developed on the photosensitive drum 12. An intermediate transfer belt (intermediate transfer medium) 15 that forms a toner image (monochrome image or color image) that can be transferred and recorded on the recording paper P, and the conveyed recording paper P is the intermediate transfer belt 15. And a transfer roller 16 for conveying the target image toner image carried by the intermediate transfer belt 15 onto the recording paper P to be nipped and conveyed, and a target image toner image. The recording paper P transferred and conveyed is heated and pressed to fix the toner image on the surface thereof, and the pair of fixing rollers 17 for nipping and conveying the recording paper P further downstream, and the photosensitive drum 12. Similarly to the waste toner tank 18 that collects and stores the toner remaining on the blade 18a, the toner remaining on the intermediate transfer belt 15 is stored. Over a waste toner tank 19 for storing collected by the blade, and a. The intermediate transfer belt 15 and the transfer roller 16 and the fixing roller pair 17 of this image recording apparatus also have a function of transporting the recording paper P, and thus constitute a part of the paper transporting apparatus described below. Yes.

  Briefly, the paper transporting device is detachably set at the lower part of the main body of the device, and a paper cassette 21 on which a plurality of recording papers P are stacked, and a recording paper raised by a lifting plate 21a on the bottom surface of the paper cassette 21. A pick-up roller 22 that pulls out the uppermost recording sheet P by rotating in pressure contact with the P-bundle and feeds it to a conveying path formed so as to extend along the substantially right side of the apparatus. The pair of relay transport rollers 23a and 23b that receive the recording paper P and further nipping and transporting the recording paper P to the upper transport path on the downstream side, and the recording paper P transported into the transport path by the relay transport roller pair 23a and 23b The intermediate transfer belt 15 and the transfer roller 16 of the image recording apparatus positioned on the image recording apparatus are nipped and conveyed to the image recording position. A fixed image is formed on one side of the roller pair 24 and the registration roller pair 24 that is transported through a transport path that passes between the intermediate transfer belt 15 and the transfer roller 16 or between the pair of fixing rollers 17 positioned further above. And a pair of paper discharge rollers 26a and 26b for receiving the recording paper P, carrying it out onto the paper discharge table 29 at the top of the apparatus main body, and discharging and stacking it. The sheet conveying apparatus includes a re-conveying path for inverting the recording sheet P on which the image is formed on one side and sending it to the conveying path on the upstream side of the registration roller pair 24 and an intermediate conveying roller disposed in the path. A pair 27 is provided, and when the pair of paper discharge rollers 26a and 26b is reversed, the intermediate conveyance roller pair 27 receives the recording paper P sent into the re-conveyance path and transfers it to the registration roller pair 24. Images can be formed on both sides of the recording paper P. In addition, the sheet conveying apparatus includes a manual conveyance path for sending the recording sheet P inserted from a manual insertion port (not shown) to the conveyance path on the upstream side of the registration roller pair 24, and manual conveyance provided in the path. The pair of rollers 28 is provided, and the inserted recording paper P is received by the manual feed roller pair 28 and transferred to the registration roller pair 24, whereby an image can be formed on one side of the recording paper P.

  As a result, the image forming apparatus can transfer the toner image obtained by developing the electrostatic latent image by attaching toner onto the surface of the photosensitive drum 12, on one side of the recording paper P conveyed via the intermediate transfer belt 15. Images can be formed by transferring to both sides.

  In this image forming apparatus, the developing cartridge 14a in the rotary developing device 14 rotates the developing roller 14c facing the surface of the photosensitive drum 12 with a gap in synchronism with the electrostatic latent image formed on the surface. The toner is developed by transferring and adhering the toner to the toner, and the supply roller 14d rotating in the toner storage space of the developing cartridge 14a is pressed against the developing roller 14c to rotate the toner. To supply. Further, the rotary developing device 14 is configured to switch the developing cartridge 14a that rotates about the rotating shaft 14e and opposes the surface of the photosensitive drum 12, so that yellow (Y), cyan (C), A color image formed by superimposing magenta (M) and black (K) toner on the surface of the intermediate transfer belt 15 is transferred onto the recording paper P, or a monochrome image formed with black (K) toner is recorded on the recording paper P. To form an image.

  In this image forming apparatus, since the photosensitive drum 12 rotates clockwise in FIG. 1, the developing roller 14c of the developing cartridge 14a rotates counterclockwise in FIG. 1, and therefore, from the developing roller 14c to the photosensitive drum. A part of the toner to be transferred to the toner 12 scatters and floats on the downstream side in the rotation direction. For this reason, an exhaust duct 30 having an upper portion in the vicinity of the opposite position (development position) as the suction port is disposed on the downstream side in the rotation direction of the developing roller 14c and the photosensitive drum 12.

  As shown in FIG. 2, the exhaust duct 30 has an upper portion in the vicinity of the developing position where the developing roller 14c faces the photosensitive drum 12, that is, an upper portion in the vicinity of the developing position on the inside of the main body of the rotary developing device 14 as an inlet side. A suction port 31 to be sucked, and after detouring so as to cover the upper side of the rotary developing device 14 from the suction port 31 toward the side of the side surface side cover 20 (shown in FIG. 1), And an exhaust port 33 disposed in the vicinity of the lower portion of the rotary developing device 14 adjacent to the side surface cover 20 as an outlet side for discharging suction air through the exhaust passage 32. And.

  Here, in the exhaust duct 30, a filter 34 that adsorbs toner mixed in the suction air is disposed in an exhaust path 32 on the upper side of the rotary developing device 14, and the toner from the exhaust air that passes through the exhaust path 32 is disposed. By adsorbing and removing the toner, the exhaust air discharged from the exhaust port 33 does not contain toner and contaminates the surroundings. Further, a centrifugal fan 35 (shown in FIG. 6) is disposed at the exhaust port 33 of the exhaust duct 30, and the air in the vicinity of the development position sucked from the suction port 31 by the centrifugal fan 35 in the exhaust path 32. After passing through the filter 34, the air is exhausted from the exhaust port 33. In the centrifugal fan 35, the exhaust path 32 has a filter 34 interposed in the exhaust flow path, or the exhaust path 32 extends from the inside of the main body of the rotary developing device 14 to the lower side of the side exterior cover 20. Since the exhaust passage is narrowed toward the exhaust port 33 as will be described later, the exhaust passage has a stable suction characteristic that is more resistant to throttling loss than the axial fan. Selected as a thing. Thus, even if the centrifugal fan 35 has a strong throttling effect on the flow path of the exhaust path 32, the centrifugal fan 35 can suck ambient air from the suction port 31 and exhaust it from the exhaust port 33 without generating a loud noise. Since the centrifugal fan 35 can be installed in the exhaust port 33 having a long flow path from the suction port 31, a space is secured in the vicinity of the rotary developing device 14 in which the axial fan or the like has been installed. In this image forming apparatus, the power supply substrate 50 can be installed.

  The exhaust path 32 is connected to the first path 32a from the inlet 31 to the filter 34 inlet, the second path 32b from the outlet of the filter 34 to the adjacent position of the side exterior cover 20, and the second path 32b. The third path 32c to the exhaust port 33 at the adjacent position of the side surface cover 20 is divided and assembled, and is formed so as to face the outer peripheral cover 14f that the rotary developing device 14 rotates. Duct plates (facing plates) 41 to 43 define the exhaust passage.

  The duct plate 41 is installed adjacent to the upper outer peripheral cover 14 f of the rotary developing device 14. The intermediate transfer belt positioned above the developing position of the rotary developing device 14 is installed on the duct plate 41. The transfer unit cover 25a of the intermediate transfer unit 25 configured to be detachable from the apparatus main body 15 and the power supply cover 50a that houses the power supply substrate 50 are connected to and face the exterior 34a on the upper side of the filter 34. That is, the transfer unit cover 25a and the power supply cover 50a face the duct plate 41 to define the first path 32a and the second path 32b.

  The duct plate 42 is installed so as to be adjacent to the outer peripheral cover 14f on the side of the rotary developing device 14, and is connected to the duct plate 41. The duct plate 42 is connected to the power supply cover 50a. It is installed so that the duct plate 43 adjacent to the side surface exterior cover 20 faces. That is, the duct plates 42 and 43 face each other to define the third path 32c.

  In short, the exhaust duct 30 includes the transfer unit cover 25a, the power supply cover 50a, and the duct plate 41 so that the outer peripheral cover 14f (outer peripheral surface) of the rotary developing device 14 is covered by the first to third paths 32a to 32c of the exhaust path 32. As shown in FIG. 4, the transfer unit cover 25a, the power supply cover 50a, and the duct plate 41 cover the depth direction (main scanning direction) on the upper side of the rotary developing device 14, and the rotary development thereof. Duct plates 42 and 43 disposed between the device 14 and the side surface exterior cover 20 are also covered in the depth direction.

  As a result, the exhaust duct 30 sucks the vicinity of the developing position of the rotary developing device 14 from the suction port 31 and exhausts air from which the scattered toner has been adsorbed and removed by the filter 34 from the exhaust port 33. 14 is installed so as to largely cover from the upper side of the outer surface of 14 to the lower side of the side of the side surface exterior cover 20. Therefore, the exhaust duct 30 covers the heat generating body in the apparatus, for example, the power supply board 50 that supplies power to each part of the apparatus so as to hide the outer surface of the main body of the rotary developing device 14, and as shown in FIG. The outer surface of the main body of the rotary developing device 14 is also covered from the drive motors 51 and 52 of the rotary developing device 14.

  Specifically, the power supply substrate 50 supplies a large current to the drive motors such as the laser beam scanning device 11 and the photosensitive drum 12 and also supplies a large current to the heaters of the fixing roller pair 17. Since power is supplied, considerable heat is generated. However, the exhaust duct 30 is interposed between the power supply substrate 50 and the rotary developing device 14, so that the heat generated by the power supply substrate 50 is not directly transmitted to the rotary developing device 14. The heat generated by the power supply substrate 50 can be removed by exchanging heat with the exhaust (air) received by the exhaust duct 30 and flowing through the exhaust duct 30, and the toner contained in the developing cartridge 14 a of the rotary developing device 14 can be removed. It will not be affected.

  Further, the drive motor 51 of the rotary developing device 14 has a drive gear 51a fixed to the rotating shaft in a gear shape formed on the outer periphery of one end of the exterior cover 14f of the rotary developing device 14 via the transmission gear 51b. The entire rotary developing device 14 is rotationally driven by meshing, and for this reason, a large amount of electric power is consumed from the power supply substrate 50 to generate heat. The drive motor 52 meshes a drive gear 52a fixed to the rotating shaft with the drive gear of the supply roller 14d via the transmission gear trains 52b to 52d, and the drive gear of the supply roller 14d includes Since the driving gear of the developing roller 14c is engaged and the supply roller 14d and the developing roller 14c are rotated at a high speed, a large amount of electric power is consumed from the power supply substrate 50 to generate heat. However, the exhaust duct 30 is interposed between the drive motors 51 and 52 and the rotary developing device 14 so that the heat generated by the drive motors 51 and 52 is not directly transmitted to the rotary developing device 14. The heat generated by the drive motors 51 and 52 can be carried away by exchanging heat between the exhaust duct 30 and the exhaust flowing through the exhaust duct 30, and the toner contained in the developing cartridge 14a of the rotary developing device 14 is affected. You will not receive.

  Furthermore, the power supply board 50 is accommodated in a power supply cover 50a that defines the second path 32b of the exhaust path 32. The power supply cover 50a is made of a material having excellent thermal conductivity, for example, a metal plate such as a steel plate. It is produced by. As a result, the heat generated from the power supply board 50 is efficiently exchanged (absorbed) with the exhaust flowing in the exhaust duct 30 and effectively taken away, and the temperature rise in the surroundings is reliably suppressed, and the inside of the developing cartridge 14a It is possible to more reliably avoid the influence of the toner. Here, it goes without saying that the exhaust duct 30 may be entirely made of a steel plate or the like, not just the power supply cover 50a. As a result, the power supply substrate 50 can be disposed at a position close to the rotary developing device 14, and the degree of freedom in layout can be improved.

  In addition, as shown in FIG. 4, the exhaust path 32 is configured such that rectifying plates 41 a to 41 e and 42 a to 42 e formed in a rib shape so as to face the power supply cover 50 a and the duct plate 43 stand vertically to the duct plates 41 and 42. It is installed. The rectifying plates 41a to 41e and 42a to 42e divide a long exhaust flow path (second and third paths 32b and 32c) from the outlet side of the filter 34 to the lower side of the side exterior cover 20 into a plurality of flow paths. In addition, rectification (regulation) is performed so that the exhaust flow path is narrowed toward the exhaust port 33 disposed on the front side surface of the apparatus main body. The rectifying plates 41a and 41e are configured in a wall shape in which both corners of the duct plate 41 separated from the filter 34 are floated so as to secure a space on the back side (rotary developing device 14 side) for convenience of layout. ing. Further, the duct plates 41 to 43 are formed so as to protrude outward from the rectifying plates 41a, 41e, 42a, and 42e so as to cover the outer surface of the rotary developing device 14 as much as possible to block noise. Yes.

  The rectifying plates 41 a to 41 e have a width in the depth direction of approximately 1/2 from the outlet side of the filter 34 extending in the depth direction as well as the suction port 31 of the exhaust duct 30 that sucks the vicinity of the developing position of the rotary developing device 14. It is gradually narrowed down to the center so that it becomes 2. The rectifying plates 42a to 42e are connected to the respective rectifying plates 41a to 41e so as to be continuous from the center in the depth direction to the exhaust port 33 on the front side of the apparatus main body, and have a width in the depth direction. The suction port 31 is squeezed so as to be approximately 1/5.

  The rectifying plates 41a to 41e and 42a to 42e define exhaust passages 45a to 45e from the outlet side of the filter 34 to the exhaust port 33, and the capacity of the passage space of the exhaust passages 45a to 45e is reduced. The exhaust passages 45a to 45e are squeezed while being bent so as to converge from the full depth direction to the small exhaust port 33 only on the front surface side. From this, the flow regulating plates 41a to 41e and 42a to 42e adjust the capacity of the flow passage spaces of the exhaust flow passages 45a to 45e according to the degree of bending thereof, and the exhaust flow passages 45a and 45d on both sides In addition to the central exhaust passages 45b and 45c being bent at two locations, the central portion and the front surface side, the central exhaust passages 45b and 45c are bent to approach the central portion from the outlet side of the filter 34, thereby producing a throttling effect. The capacity of the flow path space is set larger than that of the central exhaust flow paths 45b and 45c.

  As a result, the exhaust duct 30 can suck the outlet side of the filter 34 evenly for each of the exhaust passages 45a to 45e and exhaust the exhaust duct 30 efficiently. It is possible to avoid a temperature increase due to formation of a heat reservoir in the path 32.

  Thus, in this embodiment, since the exhaust duct 30 is installed so as to cover the side surface cover 20 side from the upper side of the rotary developing device 14, the heat generated by the power supply substrate 50 and the drive motors 51 and 52 is generated by the rotary developing device. The heat can be carried away by the exhaust flowing through the exhaust duct 30 before reaching the developing cartridge 14a in the toner 14, and the toner in the developing cartridge 14a can generate heat without installing a dedicated heat insulating material ( It is possible to effectively avoid being affected by temperature rise. Therefore, by diverting the exhaust duct 30, it is possible to form a high-quality image with high reliability without occupying a space with a dedicated heat insulating material or causing a high cost.

  Next, FIG. 7 is a diagram showing a second embodiment of the image forming apparatus according to the present invention. In addition, since this embodiment is comprised substantially the same as the above-mentioned embodiment, the same code | symbol is attached | subjected to the same structure and a characteristic part is demonstrated.

  In FIG. 7, the image forming apparatus includes an image recording apparatus and a sheet conveying apparatus, as in the above-described embodiment, and this image forming apparatus has its developing roller 14 c at the time of image formation by the rotary developing device 14. Therefore, in addition to the exhaust duct 30, an exhaust duct 60 is additionally provided.

  The exhaust duct 60 has a lower portion near the developing position (upstream in the rotation direction of the developing roller 14c and the photosensitive drum 12), whereas the exhaust duct 30 has the suction port 31 disposed in the upper portion near the developing position by the rotary developing device 14. A suction port 61 is arranged on the side), and in the exhaust path 62 after the suction port 61, a filter 64 for adsorbing and removing sucked toner is interposed in the same manner as the exhaust duct 30, and the centrifugal fan 35 is shared. As shown in FIG.

  The exhaust duct 60 is adjacent to the outer peripheral cover 14 f of the rotary developing device 14 by the exhaust path 62 being lowered downward from the suction port 61 between the rotary developing device 14 and the waste toner tank 18. After covering the side surface of the inside of the apparatus, it is detoured so as to cover the lower side thereof and connected to the exhaust port 33. Needless to say, the exhaust duct 60 is installed between the rotary developing device 14 and the waste toner tank 18 so as not to interfere with the optical path of the laser light L from the laser light scanning device 11.

  The exhaust path 62 is extended so that the duct plate 42 defining the exhaust path 32 of another path covers from the lower side to the side of the outer peripheral cover 14 f of the rotary developing device 14. A duct plate 66 is installed and defined so as to face each other. Like the exhaust path 32, the duct plate 66 extends in the depth direction and covers the entire side from the side of the rotary developing device 14 to the lower side.

  Thereby, the exhaust duct 60 can exhaust the air from the suction port 61 by sucking the lower side near the developing position of the rotary developing device 14 from the suction port 61 and adsorbing and removing the toner spilled by the filter 64 from the exhaust port 33. In addition, the outer surface of the rotary developing device 14 can be largely covered from the side of the inside of the device to the lower side of the side surface exterior cover 20 where the exhaust port 33 is installed. Thus, the exhaust duct 60 covers the laser beam scanning device 11 so as to conceal the outer surface of the main body of the rotary developing device 14 in addition to the power supply substrate 50 and the drive motors 51 and 52 which are heating elements in the apparatus. ing.

  Specifically, the laser beam scanning device 11 incorporates a polygon scanner that rotates at a very high speed so that the laser beam L is deflected and scanned together with a laser oscillator (not shown) that emits the laser beam L. Accompanied by. However, an exhaust duct 60 is interposed between the laser beam scanning device 11 and the rotary developing device 14 so that heat generated by the laser beam scanning device 11 is not directly transmitted to the rotary developing device 14. The heat generated by the laser beam scanning device 11 can be carried away by exchanging heat between the exhaust duct 60 and the exhaust flowing through the exhaust duct 60, and the toner contained in the developing cartridge 14a of the rotary developing device 14 can be removed. It will not be affected.

  As in the exhaust path 32, the exhaust path 62 is provided with a baffle plate so that a plurality of divided exhaust flow paths are formed, and the exhaust flow path is narrowed toward the exhaust port 33. Rectified (regulated).

  As described above, in the present embodiment, in addition to the operational effects of the first embodiment, in addition to the exhaust duct 30 of the exhaust path 32 that covers the side surface cover 20 side from the upper side of the rotary developing device 14, the rotary developing device. 14 is provided with the exhaust duct 60 of the exhaust path 62 covering the side surface from the inner side of the apparatus to the lower side, so that the entire outer surface of the rotary developing device 14 can be largely covered, and the toner in the developing cartridge 14a can be covered. In addition to the power supply substrate 50 and the drive motors 51 and 52, the influence of heat generation (temperature rise) from the laser beam scanning device 11 can be effectively avoided, and a high-quality image can be formed with higher reliability. . Further, since the exhaust ducts 30 and 60 are sucked and exhausted by the single centrifugal fan 35 with the exhaust port 33 in common, the space near the intake ports 31 and 61 is occupied by the exhaust fan. Therefore, the degree of freedom of layout of other parts can be improved.

  Next, FIG. 8 is a view showing a third embodiment of the image forming apparatus according to the present invention. In this embodiment, the layout of each part of the apparatus is changed from that of the above-described embodiment. However, since the functions are the same, the description will be simplified and the same components will be denoted by the same reference numerals. The characteristic part will be described.

  In FIG. 8, the image forming apparatus includes an image recording apparatus and a sheet conveying apparatus, as in the above-described embodiment. In the above-described embodiment, the image forming apparatus is conveyed along the schematic right side of the apparatus. By passing the recording paper P in the path, the recording paper P is nipped and conveyed between the intermediate transfer belt 15 and the transfer roller 16 or between the fixing roller pair 17 to form an image on one side. Thus, the recording paper P pulled out from the paper cassette 21 is reversed and transported in the horizontal direction, whereby the recording paper P is sandwiched and transported between the intermediate transfer belt 75 and the transfer roller 76 or between the fixing roller pair 77. An image is being formed.

  Briefly, the rotary developing device 14 and the photoconductor drum 12 are arranged in the same manner as in the above-described embodiment, by placing the laser beam scanning device 71 and the charger 73 on the top of the photoconductor drum 12, thereby electrostatic latent. An image or a toner image is formed.

  The intermediate transfer belt 75 is disposed below the photosensitive drum 12 and receives the toner image developed by the rotary developing device 14. The intermediate transfer belt 75 receives the recording paper P that has been conveyed in reverse from the paper cassette 21. Further, the toner image is transferred while being sandwiched between the lower transfer roller 76 and conveyed in the horizontal direction as it is.

  The fixing roller pair 77 is disposed at the same level as the intermediate transfer belt 75 and the transfer roller 76, and the recording paper P sandwiched and conveyed between them is heated and pressed to fix the toner image on the surface thereof. Thereafter, the recording paper P is passed through a conveyance path along the schematic left side of the apparatus, and is discharged onto and discharged from a discharge table 79 at the top of the apparatus.

  That is, in the rotary developing device 14, the exhaust duct 30 is interposed between the heating substrate such as the power supply substrate 50 and the laser beam scanning device 71 disposed on the upper side, and the fixing disposed on the lower side thereof. An exhaust duct 60 is interposed between the roller pair 77. Since the fixing roller pair 77 also includes a drive motor for heating and nipping and conveying the recording paper P, the fixing roller pair 77 serves as a heating element. However, similar to the above-described embodiment, the heat generated by the fixing roller pair 77 is generated by the exhaust duct 60. And can be removed by exchanging heat with the exhaust flowing in the interior thereof, so that the toner accommodated in the developing cartridge 14a of the rotary developing device 14 is not affected.

  As described above, in the present embodiment, in addition to the operation and effect of the second embodiment, the toner in the developing cartridge 14a is used as the fixing roller even in a layout in which the fixing roller pair 77 is disposed below the rotary developing device 14. It is possible to effectively avoid being affected by the heat generation (temperature rise) of the pair 77, and it is possible to form a high-quality image with high reliability.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea. For example, this image forming apparatus can be applied not only to a printer but also to a facsimile or a copier using an electrophotographic system.

1 is a perspective front view illustrating an overall configuration of an image forming apparatus according to a first embodiment of the present invention. It is a partially expanded perspective front view which shows the principal part structure. It is a partially expanded perspective front view which shows the principal part structure. It is a perspective view which shows the components of the principal part. It is a perspective view which shows the structure of the principal part components. It is an expansion | deployment top view which shows the structure of the principal part component. It is a figure which shows 2nd Embodiment of the image forming apparatus which concerns on this invention, and is a partially expanded perspective front view which shows the principal part structure. It is a figure which shows 3rd Embodiment of the image forming apparatus which concerns on this invention, and is a see-through | perspective front view which shows the schematic whole structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 71 Laser beam scanning device 12 Photoconductor drum 13, 73 Charger 14 Rotary developing device 14a Developing cartridge 14c Developing roller 15, 75 Intermediate transfer belt 16, 76 Transfer roller 17, 77 Fixing roller pair 18, 19 Waste toner tank 20 Side exterior cover 25 Intermediate transfer unit 25a Transfer unit cover 30, 60 Exhaust duct 31, 61 Inlet port 32, 62 Exhaust path 33 Exhaust port 34, 64 Filter 35 Centrifugal fans 41-43, 66 Duct plates 41a-41e, 42a-42e Rectifier plates 45a to 45e Exhaust flow path 50 Power supply board 50a Power supply covers 51, 52 Drive motor P Recording paper L Laser light

Claims (6)

A carrier that carries a toner image in which an electrostatic latent image is formed on the surface and develops the electrostatic latent image; a developer cartridge that develops the toner by attaching the toner to the electrostatic latent image on the surface of the carrier; And a rotary developing device that stores the developing cartridge around a rotation shaft and rotates about the rotation shaft, and performs an image forming apparatus that forms a desired image by switching the developing cartridge facing the surface of the carrier. There,
It has an exhaust duct that sucks the vicinity of the development position where toner is attached to the carrier and exhausts it outside the apparatus,
An image forming apparatus, wherein the exhaust duct is formed with a path so as to hide an outer surface of the rotary developing device from a heating element.   The heating element operates a power supply base that supplies power to each part of the apparatus, a scanner unit that forms an electrostatic latent image on a carrier, a fixing unit that fixes toner formed by heating and press-contacting a recording medium, or a driving mechanism. The image forming apparatus according to claim 1, wherein the number of driving motors is one or more than two.   3. The image forming apparatus according to claim 1, wherein at least a part or all of members that define a path on the side of the heating element is made of a material having excellent thermal conductivity.   The exhaust duct divides the exhaust duct from the pair of facing plates facing the outer peripheral surface around which the rotary developing device rotates and the suction plate side to the exhaust port side between the facing plates into a plurality of portions. The image forming apparatus according to claim 1, further comprising a current plate that regulates air flowing in the flow path.   The flow straightening plate of the exhaust duct divides the exhaust flow path so that suction can be performed substantially uniformly from the wide suction port and narrows it toward the narrow exhaust port, and the flow path space for each exhaust path becomes substantially uniform. The image forming apparatus according to claim 4, wherein the exhaust passage is defined as described above.   The rectifying plate of the exhaust duct is set so that an exhaust passage having a larger bend between the suction port and the exhaust port has a larger passage space. Image forming apparatus.

Images