JP2008164905A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which of eliminates trouble caused by melting of waste toner to be conveyed along the waste toner conveying means, without increasing the size of the apparatus even if a space between the fixing housing and process housing is narrow. <P>SOLUTION: The fixing housing 74 of a fixing unit 7 is located above a process casing PH incorporating the waste-toner conveying means 62, with a space S. In a stay 113 holding the fixing housing 74 in its lengthwise direction, a vent hole 113f by which a space above the end of the space S communicates with an air path T is disposed in the lengthwise direction. The apparatus includes: an exhaust port 115 formed in the exterior housing of the apparatus and communicating with the air path T; and a fan 117 by which a current of air flowing toward the exhaust port 115 is created in the air path T. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus in which a fixing device that thermally fixes a toner image on a recording sheet and a waste toner transport unit that transports waste toner are positioned through a narrow gap.

  An image forming apparatus used in a copying machine, a printer, a facsimile, and a multifunction machine having at least two of these functions performs selective exposure according to image information on the surface of a uniformly charged photosensitive drum. Then, a latent image is formed, the formed electrostatic latent image is developed to form a toner image, and the toner image is transferred to a recording sheet to form an image. The recording sheet is discharged to a discharge tray after the toner image is fixed by the fixing unit. In general, a fixing device melts and fixes unfixed toner on a recording sheet by pressing a heating roller containing a heat source such as a halogen heater against the recording sheet. On the other hand, the toner remaining on the surface of the photosensitive drum is removed by a cleaning blade or the like, and is transported to a waste toner container by a transport paddle, a screw, or the like provided in the waste toner transport unit.

  Incidentally, a fixing device including a heating roller, a heat generation source, and the like is accommodated in a fixing housing. The waste toner conveying unit is unitized as a process cartridge together with other image forming units, and is accommodated in an exterior housing (hereinafter also referred to as a process housing) of the process cartridge. Due to the demand for downsizing of the image forming apparatus, the gap between the fixing housing and the process housing becomes narrow, and the air in the gap is warmed by exhaust heat from the fixing device and stays as hot air. When the temperature of the hot air rises due to continuous operation for a long time, if the waste toner transport unit is accommodated in the upper part of the process cartridge, the temperature in the waste toner transport unit rises. The waste toner dissolves when the temperature in the waste toner transport unit rises to the softening point of the waste toner, but the temperature in the waste toner transport unit decreases when the fixing unit no longer generates heat when the operation ends. As a result, the waste toner that has melted in the waste toner transport unit is fixed, and the drive load of the waste toner transport is increased by the transport paddle or screw, which may cause problems such as locking of the drive unit such as a motor. Arise.

Therefore, for example, Patent Document 1 discloses that fans that forcibly exhaust hot air are provided at both ends in the longitudinal direction above the fixing device, and the hot air staying above the fixing device is stably discharged out of the apparatus. . On the other hand, for example, in Patent Document 2, an inner wall that separates the waste toner conveying portion and the process housing is provided in the process cartridge, and an air passage is formed between the process housing and the inner wall, and the heat is discharged from the fixing device. It is disclosed to reduce the influence on the waste toner conveying unit.
JP 2002-62771 A JP 2000-81828 A

  However, as disclosed in Patent Document 1, it has been difficult to add a new fan due to layout restrictions due to a request for downsizing the apparatus. On the other hand, as disclosed in Patent Document 2, the inner wall is formed in the process cartridge and the air passage is formed, so that the process cartridge increases in size, so that the gap between the fixing housing and the process housing is reduced. There was a problem that was against the request.

  The present invention has been made in view of such a problem, and even when the gap between the fixing housing and the process housing is narrow, the waste toner transported through the waste toner transport unit is not increased in size. It is an object of the present invention to provide an image forming apparatus capable of eliminating problems caused by melting.

  In order to achieve the above object, the image forming apparatus according to claim 1, a fixing unit that heat-fixes the toner image on a recording sheet onto which the toner image formed on the surface of the photoconductor is transferred, and the photoconductor. And a waste toner transport unit that removes and transports the toner remaining on the surface of the image forming apparatus. A fixing unit that accommodates the fixing unit via a gap above a casing in which the waste toner transport unit is provided. A housing member is located, and a holding member that holds the fixing housing in the longitudinal direction is provided with a vent hole that communicates with the air passage above the end of the gap in the longitudinal direction.

  An image forming apparatus according to a second aspect is the image forming apparatus according to the first aspect, wherein an exhaust port that is formed in an exterior housing of the device and communicates with the air passage, and the air passage faces the exhaust port. And a fan for generating an air flow.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the casing is an exterior housing of a process cartridge that houses the waste toner conveying unit, and the holding member is the This is a stay that connects the side walls of the exterior chassis of the apparatus over the longitudinal direction of the fixing housing.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the holding member has a vertical piece that holds the fixing housing, and is horizontally opposite to the fixing housing from a lower end of the vertical piece. A horizontal piece extending to the side, and the vent is provided by forming a slit at a corner formed by the vertical piece and the horizontal piece.

  According to the image forming apparatus of the first aspect, the fixing housing that accommodates the fixing unit via the gap is positioned above the casing in which the waste toner conveying unit is provided. Due to the demand for downsizing of the apparatus, the gap between the casing and the fixing housing is narrow, and the exhaust air generated from the fixing means raises the temperature of the air existing in the gap and becomes hot air, which may cause hot hot air to stay. is there. When hot hot air stays, the heat of the hot air is transmitted and the temperature of the waste toner conveying means rises. In view of this, the holding member is provided with a vent that communicates the end of the gap with the air passage. Therefore, it is possible to prevent the hot air existing in the gap from flowing out into the air passage through the vent and being released, and the hot air from staying in the gap. Therefore, it is possible to suppress an increase in the temperature of the waste toner conveying unit, and it is possible to eliminate a problem caused by melting of the waste toner conveyed by the waste toner conveying unit. Further, a vent hole communicating with the air passage is provided above the end of the gap. Therefore, by using the rising airflow due to the temperature gradient, the hot air existing in the gap easily flows out to the air passage through the vent hole, and the temperature rise of the waste toner conveyance path means can be suppressed more effectively. Further, since the vent hole is provided in the holding member that holds the fixing housing in the longitudinal direction in the longitudinal direction, the temperature of the waste toner conveying means that is adjacent to the fixing means via the gap is increased over the entire longitudinal direction of the fixing means. Can be suppressed. Furthermore, since the temperature rise of the waste toner conveying means can be suppressed only by adding a vent to the holding member that is an existing member for holding the fixing housing, an air passage is provided in the case of adding a fan or in the process unit. The apparatus does not increase in size as in the case. Note that providing the holding member with the vent in the longitudinal direction means that the holding member has one or a plurality of vents in the longitudinal direction, and the vent does not necessarily have to be provided over the entire longitudinal direction. .

  According to a second aspect of the present invention, the image forming apparatus includes an exhaust port that is formed in the exterior housing of the device and communicates with the air passage, and a fan that generates an air flow toward the exhaust port in the air passage. Therefore, the hot air existing in the gap is forcibly discharged from the exhaust port to the outside of the apparatus through the air passage by the fan, so that the temperature rise of the waste toner conveying means can be more effectively suppressed. In addition, it is possible to use a fan provided for discharging ozone generated when charging the surface of the photoreceptor as this fan, and in this case, it is not necessary to add a new fan, so the apparatus is Does not increase in size.

  According to another aspect of the image forming apparatus of the present invention, the casing is an exterior housing of a process cartridge that houses waste toner conveying means. Therefore, the present invention can be applied to an image forming apparatus in which a process cartridge is detachably provided to the apparatus main body. Further, the holding member that holds the fixing housing in the longitudinal direction is a stay that connects the side walls of the exterior chassis of the apparatus across the longitudinal direction of the fixing housing. Therefore, the fixing housing can be stably held on the exterior chassis.

  According to another aspect of the image forming apparatus of the present invention, the holding member includes a vertical piece that holds the fixing housing, and a horizontal piece that extends horizontally from the lower end of the vertical piece to the opposite side of the fixing housing. A vent is provided by forming a slit at a corner formed by the piece. Since the fixing housing and the exterior housing of the process cartridge are close to each other via a gap, the horizontal piece of the holding member that holds the fixing housing and the exterior housing of the process cartridge are close to each other. Then, the hot air existing in the gap between the fixing housing and the exterior housing of the process cartridge flows into the gap between them, and the temperature in the process unit rises, which may affect various devices in the process unit. . However, since the vent is provided by forming a slit at the corner formed by the vertical piece and the horizontal piece of the holding member, the hot air flowing into the gap between the horizontal piece and the exterior housing of the process cartridge is reduced, and the process unit The temperature rise inside can be suppressed.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. A copy / facsimile multifunction peripheral 100 equipped with an image forming apparatus according to an embodiment of the present invention has a built-in image forming apparatus for forming an image on a recording sheet, as shown in FIG. A main body 110, a reading table 120 functioning as a flatbed scanner for reading an image of an original, and an operation panel 130 for inputting start of image reading and image formation.

  As shown in FIG. 2, the main body 110 is provided with a paper feeding cassette 101 for sequentially supplying recording paper for recording images on the bottom of the apparatus, and above the paper feeding cassette 101. An image forming unit 102 is disposed, and a paper discharge tray 103 is disposed above the image forming unit 102. A conveyance path 104 for conveying recording paper from the paper feed cassette 101 to the paper discharge tray 103 extends upward from one end side of the paper feed cassette 101 to the image forming unit 102 and further extends upward. Then, it is formed so as to bend in the horizontal direction and lead to the paper discharge tray 103. Further, the reverse conveyance path 105 that reverses the recording sheet on which the image is recorded on one side by the image forming unit 102 and sends the recording sheet to the image forming unit again is substantially downward from between the image forming unit 102 and the paper discharge tray 103. Further, it is formed so as to be connected to the conveyance path 104 on the upstream side of the paper feed cassette 101.

  The paper feed cassette 101 has a box shape that can store recording paper of various sizes, and is provided at the bottom of the apparatus so that it can be pulled out, so that it can be loaded with recording paper as required. The recording paper stored in the paper feed cassette 101 is always positioned at the paper feed position at one end of the uppermost paper by the guide 101a. A paper feed mechanism 101b including a pickup roller, a reverse roller, and a separation pad is provided at the paper feed position, and the recording paper is fed into the transport path 104 one by one.

  The image forming unit 102 includes a charging device 2, an LED head 3, a developing device 4, a transfer roller 5, and a cleaning device 6 disposed around the photosensitive drum 1, and a conveyance path 104 on the downstream side of the photosensitive drum 1. And a fixing device 7 disposed in the space. Among these, the photosensitive drum 1, the charging device 2, and the cleaning device device 6 are housed in a cartridge as a process unit PU and integrated. The process unit PU includes a process housing PH made of synthetic resin that houses and houses the photosensitive drum 1, the charging device 2, and the cleaning device device 6 as an exterior housing, and faces the transfer roller 5 of the photosensitive drum 1. A portion is exposed from the process housing PH.

  The photosensitive drum 1 is rotated at a predetermined speed by a motor, and the surface thereof is charged to a constant voltage by the charging device 2. The charging device 2 is a non-contact corona charging method called a so-called scorotron charger, in which a discharge wire is disposed substantially at the center of a casing electrode forming a half space, and a grid electrode is provided on the photosensitive drum 1 side. The corona discharge is generated by applying a predetermined voltage to the discharge wire, and the amount of ions generated by the corona discharge is controlled by the grid electrode. The charging device 2 may employ another charging device such as a contact roller charging method instead of the non-contact corona charging method.

  The LED head 3 is a so-called self-luminous printer head in which LED arrays are arranged in parallel for the number of recording pixels and light emitted from the LED array is imaged on the surface of the photosensitive drum 1 by a selfoc lens array. The surface of the photosensitive drum 1 is selectively exposed to the body drum 1 based on the image information, and an electrostatic latent image is formed on the surface. The surface of the photosensitive drum 1 charged by the charging device 2 is attenuated by being exposed by the LED head 3, and an electrostatic latent image is formed by a potential difference from the unexposed portion. As the image information, for example, an image of a document read by the reading table 130 functioning as a flatbed scanner is transmitted to the LED head 3 as an electric signal. As the exposure device, a scanning optical system using a semiconductor laser in addition to the LED head 3 may be employed.

  The developing device 4 includes a supply roller, a development roller, and a toner container. The toner in the toner container is developed through the supply roller due to a difference in bias voltage applied to the supply roller and the development roller from an electric circuit (not shown). A toner layer is formed on the surface of the developing roller. The developing roller on which the toner layer is formed is rotated at a position close to the photosensitive drum 1, and the toner on the developing roller moves to the photosensitive drum 1 due to a potential difference from the electrostatic latent image on the photosensitive drum 1. A toner image is formed on the surface of the photosensitive drum 1 based on the electrostatic latent image. Such a developing device 4 is an example, and selection of magnetic toner or non-magnetic toner, selection of contact development method or non-contact development method, and the like are arbitrary.

  The transfer roller 5 is a roller made of EPDM foam or urethane sponge, and is pressed against the photosensitive drum 1 at a position opposed to the conveyance path 104 so that a bias voltage is applied from an application circuit (not shown). Yes. The recording sheet supplied from the sheet feeding cassette 101 via the conveyance path 104 is nipped by the photosensitive drum 1 and the transfer roller 5 and a bias voltage is applied, so that a toner image formed on the surface of the photosensitive drum 1 is formed. Transferred to recording paper.

  As shown in FIG. 3, the cleaning device 6 includes a cleaning blade 61 and waste toner transport means 62 including a transport paddle and a screw, and removes and collects toner and paper dust remaining on the surface of the photosensitive drum 1. To do. The cleaning blade 61 is pressed against the surface of the photosensitive drum 1 after transfer, and a constant voltage is applied from an electric circuit (not shown), thereby removing toner and paper dust remaining on the surface of the photosensitive drum 1 and electrostatically. Erase the latent image. Waste toner or paper dust scraped off by the cleaning blade 61 is transported to the front side of the apparatus by a waste toner transport means 62 that is rotationally driven by a motor (not shown), and is accumulated in a waste toner collection container (not shown). ing.

  As shown in FIG. 2 or 3, the fixing device 7 includes a heating roller 71 and a pressure roller 72 that are respectively disposed at positions opposed to the conveyance path 104, and is on a recording sheet conveyed through the conveyance path 104. An unfixed toner image is thermally fixed on the recording. The heating roller 71 is a hollow roller made of aluminum or the like, and a heat source 73 such as a halogen heater that generates heat by power supply from a power supply circuit (not shown) is disposed in the inner space thereof, and the surface is maintained at a predetermined temperature. . The heating roller 71 is driven to rotate at a predetermined peripheral speed by a motor (not shown). The pressure roller 72 is rotatably supported by the bearing and is pressed against the heating roller 71 with a predetermined pressing force. The pressure roller 72 is rotated by the rotation of the heating roller 71. When the recording sheet on which the unfixed toner image is transferred is nipped and conveyed between the pressure contact portions of the heating roller 71 and the pressure roller 72, the toner is melted by the heat of the heating roller 71 and pressed by the pressure contact portion. The toner image is fixed by heat. A heating roller 71 and a pressure roller 72 are combined with a cleaning roller for cleaning the surface of the heating roller 71, a temperature sensor for measuring the surface temperature of the heating roller 71, and the like, and a fixing housing 74 made of synthetic resin which is an exterior housing of the fixing device 7. Contained and contained.

  As shown in FIG. 2, the recording paper is conveyed from the paper feed cassette 101 along the conveyance path 104 to the image forming unit 102, and after the image is formed by the image forming unit 102, the recording paper is transferred to the paper discharge tray 103. Discharged. The conveyance path 104 is extended substantially upward from the paper feed cassette 101 to the image forming unit 102, and a pair of conveyance rollers 80 for nipping and conveying the recording paper is appropriately provided in the middle. A pair of paper discharge rollers 81 that nip the recording paper and discharge it toward the paper discharge tray 103 are provided at the end of the conveyance path 104. With such a conveyance path 104, a reverse C path is formed from the paper feed cassette 101 to the paper discharge tray 103.

  Further, when the recording sheet that has passed through the image forming unit 102 is reversed and supplied again to the image forming unit 102, such as when performing double-sided image formation, the trailing edge of the recording sheet is the discharge roller 81. When the sheet is conveyed to a predetermined position near the position, the paper discharge roller 81 is rotated in the reverse direction, and the conveying path of the recording paper is switched by the turning pawl 83 to be conveyed toward the reverse conveyance path 105. The reverse conveyance path 105 is extended so as to rejoin the conveyance path 104 on the upstream side of the paper feed cassette 101 from a branch point of the conveyance path 104 provided with the deflection pawl 82 substantially downward. In the middle, a pair of conveyance rollers 80 for nipping and conveying the recording paper is appropriately provided. A diverting claw 82 is provided at a branch point between the conveyance path 104 and the reverse conveyance path 105 to switch the conveyance path of the recording paper. When the recording paper is conveyed from the image forming unit 102 to the paper discharge roller 81 side, the reverse conveyance path 105 is blocked by the leading end, and when the recording paper is fed from the paper discharge roller 81 side to the reverse conveyance path 105. Operates so as to block the conveyance path 104 by the tip. In this way, the surface of the recording paper that has passed through the image forming unit 102 is reversed and supplied again to the image forming unit 102.

  As shown in FIG. 4, a schematic perspective view partially showing the appearance of the frame of the main body 110 is formed between the side walls 111 and 112 on both front and rear sides of the exterior chassis constituting the exterior portion of the frame of the main body 110 ( A stay 113 is provided to be connected in the width direction of the recording paper to be conveyed. As shown in FIG. 3 to be referred to, the fixing unit 7 is held on the vertical piece 113a of the stay 113 by a pin or the like. An opening 111 a is formed in the front side wall 111 below the stay 113 so that the process unit PU can be attached to and detached from the main body 110. The stay 113 is also a member for reinforcing the strength reduction due to the opening 111a. In this way, the fixing device 7 is arranged at a predetermined position above the process unit PU.

  As shown in FIG. 3 or FIG. 4, the stay 113 includes a horizontal piece 113b that extends horizontally from the lower end of the vertical piece 113a to the left (the direction opposite to the side where the fixing device 7 is held). It is a long member having substantially the same cross section as a whole formed by molding a thin metal plate such as stainless steel. A vent hole 113 c is formed in the vertical piece 113 a of the stay 113 in order to release hot air in the fixing device 7 due to exhaust heat of the fixing device 7. In addition, an ozone discharge slit 113d is formed in the horizontal piece 113b of the stay 113 in order to discharge ozone generated by corona discharge in the charging device 2.

  As shown in FIG. 2, the ozone generated in the charging device 2 is discharged to the air passage T through the ozone discharge slit 113d, and is guided to the exhaust port 115 by the fan 114 together with the air in the air passage T. The ozone filter 116 disposed in front of the mouth 115 is removed. The air passage T is formed by a space surrounded by the stay 113, the duct 117, and the upper exterior housing 118. The duct 117 is a space defined by the inside of the stay 113 (the side opposite to the side on which the fixing device 7 and the process unit PU are located and defined by the inner surfaces of the vertical piece 113a and the horizontal piece 113b) and the exhaust. It is a synthetic resin molded member that communicates with the opening 115, and is formed in a shape suitable for inducing air, such as a shape that draws an arc from the inside of the stay 113 toward the exhaust opening 115. The lower surface of the end portion on the stay 113 side of the duct 117 is placed on the upper end surface of the placing piece 113e extending upward from the left end (the side opposite to the side on which the vertical piece 113a is located) of the horizontal piece 113b of the stay 113. Therefore, a gap is not formed between the stay 113 and the stay 113. The upper exterior housing 118 is a synthetic resin molding member that forms a part of the exterior housing of the main body 110. The upper exterior housing 118 covers the upper portion of the stay 113 and the duct 117, and the discharge tray 103 is formed on the upper surface thereof. The fan 114 generates an air flow toward the exhaust port 115 in the air passage T, and is disposed in the vicinity of the end of the duct 117 on the exhaust port 115 side. The exhaust port 115 is an opening formed on the left side surface of the exterior housing of the main body 110 and is connected to the opening at the left end of the duct 117. The ozone filter 116 absorbs ozone sent together with the passing air, and is disposed in the duct 117 so as to be positioned between the exhaust port 115 and the fan 114.

  As shown in FIG. 3, the fixing device 7 includes a heating roller 71 whose surface is maintained at a predetermined temperature by a heat source 73. Therefore, the temperature in the fixing device 7 rises due to the exhaust heat of the fixing device 7, the air in the fixing device 7 is warmed to become hot air, and is directed upward by the rising air current due to the temperature gradient. A guide member that is located above the fixing device 7 and forms a guide surface near the terminal end of the conveyance path 104 has a large number of openings (not shown) penetrating in the vertical direction. 7 is released to the outside of the main body 110, so that most of the exhaust heat of the fixing device 7 is dissipated. Further, a part of the hot air in the fixing device 7 flows into the air passage T through the vent hole 113c formed in the vertical piece 113a of the stay 113, is guided by the fan 114, and is discharged from the exhaust port 115 to the outside of the apparatus. Released.

  However, as the temperature in the fixing device 7 rises due to the exhaust heat of the fixing device 7, the temperature of the air near the outside of the fixing device 7 also rises. Below the fixing unit 7, a process unit PU is arranged close to the fixing unit 7. Air existing in the gap S (shaded area in FIG. 3) between the fixing device 7 and the process unit PU, more specifically, between the lower surface of the fixing housing 74 and the upper surface of the process housing PH, Heated by exhaust heat and becomes hot air. In addition, the gap S is a narrow space in the vertical direction due to a request for downsizing of the apparatus, and a portion communicating with the outside of the apparatus is limited to a small part, so that hot air stays and becomes high temperature. If high-temperature hot air stays in the gap S, the heat of the hot air is transmitted, and the temperature of the waste toner conveying means 62 portion of the cleaning unit 6 accommodated in the upper portion of the process housing PH rises, causing a problem. Therefore, in the present embodiment, the stay 113 is provided with a vent 113 f that communicates with the air passage T above the left end of the gap S.

  As shown in FIGS. 3 and 4, the vent 113 f is provided by forming a slit extending in the longitudinal direction of the stay 113 at a corner formed by the vertical piece 113 a and the horizontal piece 113 b. In FIG. 4, four vent holes 113 f are provided in the stay 113, but the present invention is not limited to this. The vent 113f is preferably provided so as to be long in the longitudinal direction of the stay 113, but is stacked on the upper exterior housing 118 mounted on the upper end surface of the mounting piece 113e and the discharge tray 103 on the upper surface thereof. It may be determined appropriately from the viewpoint of strength in consideration of the weight of the recording paper and the external force applied when the fixing device 7 held by the stay 113 is attached or detached. Moreover, although the vent 113f is provided in the corner | angular part which the vertical piece 113a and the horizontal piece 113b make, it is not limited to this. In the present embodiment, a corner formed by the vertical piece 113a and the horizontal piece 113b is located above the end of the gap S, and a vent 113f is provided at this corner. By providing the vent 113f above the end of the gap S, the rising airflow due to the temperature gradient can be used, and the hot air existing in the gap S (hereinafter referred to as hot air in the gap S) passes through the vent 113f. This is because it easily flows out to the air passage T in the direction of the arrow shown in FIG.

  As described above, according to the copy / facsimile multifunction peripheral 100, the stay 113 is provided with the vent 113f communicating with the air passage T above the left end of the gap S between the fixing unit 7 and the process unit PU. The hot air in the gap S flows out to the air passage T through the vent 113f and is released, and the hot air can be prevented from staying in the gap S. Therefore, it is possible to suppress an increase in the temperature of the waste toner transport unit 62, and it is possible to eliminate a problem caused by melting of the waste toner transported by the waste toner transport unit 62. When the vent 113f was not provided, the hot air in the gap S was flowing out from the ozone discharge slit 113d of the stay 113 to the air passage T, but the hot air did not flow out sufficiently and was retained in the gap S, so the temperature was high. .

  Further, since air in the air passage T is guided to the exhaust port 115 together with ozone by the fan 114, the hot air in the gap S flows into the air passage T through the vent port 113f by forced exhaust by the fan 114, and the duct 117. The inside is guided and discharged from the exhaust port 115 to the outside of the apparatus. Therefore, it is possible to more effectively suppress the temperature rise of the waste toner conveying means 62.

  Further, since the temperature rise of the waste toner conveying means 62 can be suppressed only by adding the vent 113f to the stay 113 which is an existing member, the apparatus is not increased in size. Furthermore, the fan 114 is a fan that discharges ozone generated in the charging device 2, and a new fan is not added, so that the size of the apparatus does not increase.

  Note that the configuration of the copy / facsimile multifunction peripheral 100 shown in this embodiment is merely one aspect of the image forming apparatus according to the present invention, and various modifications can be made without departing from the scope of the present invention. is there. For example, the case where the waste toner removed by the cleaning device 6 is transported by the waste toner transport unit 62 and accumulated in the waste toner collection container has been described. However, the removed waste toner may be transported by the waste toner transport means and supplied to the developing device 4. Further, the case where the stay 113 directly holds the fixing device 7 has been described. However, the stay 113 may indirectly hold the fixing device 7 via another member.

  Further, the case where the process unit PU accommodates the photosensitive drum 1, the charging device 2, and the cleaning device device 6 has been described. However, the image forming device accommodated in the process unit PU is not limited to these combinations, and the cleaning device 6 may constitute an independent unit. The case where hot air stays in the gap S between the process housing PH and the fixing housing 74 has been described. However, as long as the fixing device 7 and the waste toner conveying unit 62 are close to each other and hot air stays in a substantially closed gap therebetween, the specific mode is not limited.

  Further, in the present embodiment, the mode in which the image forming apparatus is implemented as the copy / facsimile multifunction peripheral 100 has been described. However, the image reading apparatus is not limited to this, and a printer, a facsimile machine, a copier, and any of these multifunction peripherals. Etc. are applicable.

1 is a schematic perspective view showing an external appearance of a copy / facsimile multifunction peripheral 100 according to an embodiment of the present invention. 1 is a schematic longitudinal sectional view showing a main body 110 of a copy / facsimile multifunction peripheral 100. FIG. FIG. 3 is a schematic longitudinal sectional view showing an enlarged vicinity of a gap S of a main body 110. 2 is a schematic perspective view partially showing an appearance of a frame of a main body 110. FIG.

Explanation of symbols

1 Photoconductor drum (photoconductor)
2 Charging device 3 LED head 4 Developing device (developing means)
5 Transfer roller (transfer means)
6 Cleaning device 7 Fixing device (fixing means)
62 Waste toner conveying means 74 Fixing housing 100 Copy / facsimile multifunction machine (image forming apparatus)
111 Front side wall 112 of exterior chassis 112 Rear side wall 113 of exterior chassis Stay (holding member)
113a Vertical piece 113b Horizontal piece 113f Vent 114 Fan 115 Exhaust 117 Duct PH Process housing (exterior housing)
PU process unit S clearance

Claims (4)

Fixing means for thermally fixing the toner image on a recording sheet onto which the toner image formed on the surface of the photoreceptor is transferred;
In an image forming apparatus comprising: a waste toner conveying unit that removes and conveys toner remaining on the surface of the photoreceptor;
A fixing housing that accommodates the fixing means is located above a casing in which the waste toner conveying means is provided, and a holding member that holds the fixing housing in the longitudinal direction is positioned above the end of the gap. An image forming apparatus characterized in that a vent hole communicating with the air passage is provided in the longitudinal direction. An exhaust port formed in an exterior housing of the device and communicating with the air passage;
The image forming apparatus according to claim 1, further comprising: a fan that generates an air flow toward the exhaust port in the air passage. The casing is an exterior housing of a process cartridge that houses the waste toner conveying means;
The image forming apparatus according to claim 1, wherein the holding member is a stay that connects between side walls of an exterior chassis of the apparatus over the longitudinal direction of the fixing housing.   The holding member includes a vertical piece that holds the fixing housing, and a horizontal piece that extends horizontally from the lower end of the vertical piece to the opposite side of the fixing housing, and is formed at a corner formed by the vertical piece and the horizontal piece. The image forming apparatus according to claim 3, wherein the vent is provided by forming a slit.

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