JP5850385B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  Patent Document 1 discloses an image forming apparatus including a polygon motor and a writing unit including a casing that accommodates the polygon motor, and the polygon motor mounting portion of the casing is formed of a member having good thermal conductivity such as an aluminum material. Then, a cooling device for an image forming apparatus is disclosed, in which a fan for blowing air is disposed on the mounting portion of the polygon motor, and a heat source such as a circuit board is disposed at an outlet of cooling air from the fan.

  Japanese Patent Application Laid-Open No. 2004-26883 discloses an image forming apparatus that includes a process cartridge having at least an image carrier and a fixing device that fixes a toner image formed on the sheet by the process cartridge to the sheet. An image forming apparatus comprising an air passage provided with a fan and an exhaust fan to generate an air flow between the process cartridge and the fixing device is disclosed.

  Patent Document 3 discloses an image carrier that carries a toner image, an exposure unit that exposes the image carrier, a transfer unit that transfers a toner image formed on the image carrier onto a recording medium, and the recording medium. A fixing device that fixes the toner image transferred thereon onto the recording medium; a control unit; a power source unit; and a blowing unit that generates an air flow, upstream of the air flow generated by the blowing unit. An image forming apparatus is disclosed in which the control unit, the power supply unit, and the exposure unit are arranged on the side, and the fixing device is arranged on the downstream side.

  In Patent Document 4, an exposure unit that scans and exposes a photosensitive material by emitting a light beam in a direction transverse to the feeding direction of the photosensitive material is disposed in an internal space created by a housing having a front wall and a rear wall. In the image forming apparatus, the exposure is performed such that a gap space is created between a surface of a boundary plate provided between a front wall and a rear wall so as to partition the internal space and one surface of the casing of the exposure unit. A unit is installed and the front wall from the front wall to the gap space to create a cooling air flow path from the front outside air circulation hole formed in the front wall to the rear outside air circulation hole formed in the rear wall. An image forming apparatus is disclosed in which at least two sealing members extending in a distance are provided at intervals.

  Patent Document 5 discloses a writing light exit opening in which a writing unit provided in a housing of an image forming apparatus is provided with forced air intake means for taking in outside air, and the writing unit can discharge the air taken in toward the image forming unit side. The writing unit, the image forming unit, and the fixing device are arranged from the upstream side to the downstream side in the moving direction of the taken-in air, and the heat source of the fixing device is cooled in the middle of the moving direction of the air. Forcible intake means is provided, and forced exhaust means is provided in the vicinity of the fixing device located on the downstream side in the moving direction so as to exhaust air from the inside of the housing so that the influence of hot air from the fixing device does not affect the upstream member. An image forming apparatus is disclosed.

Japanese Patent Laid-Open No. 2002-072124 JP 2004-205651 A JP 2004-341374 A Japanese Patent Laying-Open No. 2005-250015 JP 2006-337589 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can efficiently perform intake near a discharge unit that discharges a recording medium while suppressing the influence on other characteristics and functions.

  According to a first aspect of the present invention, there is provided an image carrier that holds an image to be transferred to a recording medium, a fixing device that fixes the image onto the recording medium onto which the image has been transferred from the image carrier, and the fixing device. A discharge unit that discharges the recording medium on which the image is fixed, a stacking unit that stacks the recording medium discharged from the discharge unit, an intake unit that sucks air, the image carrier, and the fixing device. An air opening having an air intake opening between them, an air guide that guides air from the air intake opening toward the air intake means, a support that supports the fixing device, and the fixing device and the discharge portion. A recording medium guide unit that is disposed in a conveyance path for conveying the recording medium therebetween and guides the recording medium on which the image has been fixed by the fixing device to the discharge unit, and the recording medium guide unit includes: , Air into the intake opening An image forming apparatus the air passage is formed through.

  According to a second aspect of the present invention, a ventilation hole is formed in the support body so that the discharge portion and the air guide portion can pass through the periphery of the fixing device from the discharge portion. The image forming apparatus according to claim 1.

  According to a third aspect of the present invention, there is provided an image holding body for holding a latent image to be transferred to a recording medium, and the air intake means has an air guide portion for sucking the vicinity of the image holding body, and the air guide portion. Has a first air guide part and a second air guide part, and the support body has an amount of air sucked from the vicinity of the discharge part, the first air guide part and the second air guide part. 3. The image forming apparatus according to claim 1, wherein a ventilation prevention unit is provided to prevent ventilation so that one of the two is less than the other. 4.

  According to a fourth aspect of the present invention, the first air guide portion includes a first intake opening portion that opens toward the vicinity of an axial end portion of the image carrier, and the second air guide portion. The image forming apparatus according to claim 3, further comprising a second intake opening that opens toward a vicinity of an axial center of the image carrier.

  According to a fifth aspect of the present invention, the support body covers the periphery of the fixing device through a gap, and air around the fixing device is sucked into the air guide portion through the gap and the ventilation hole. Item 3. The image forming apparatus according to Item 2.

  The present invention according to claim 6 is the image forming apparatus according to claim 5, wherein a large number of the vent holes are formed corresponding to the second intake openings.

  According to the first aspect of the present invention, as compared with the case where the present configuration is not provided, the intake near the discharge portion for discharging the recording medium is efficiently performed while suppressing the influence on other characteristics and functions. It is possible to provide an image forming apparatus capable of performing the above.

  According to the second aspect of the present invention, in addition to the effect obtained by the first aspect of the present invention, the recording medium is discharged while maintaining the strength of the support as compared with the case where the present structure is not provided. It is possible to realize the intake near the section at low cost.

  According to the third aspect of the present invention, in addition to the effect obtained by the first or second aspect of the present invention, priority can be given to cooling of a part near the image carrier.

  According to the fourth aspect of the present invention, cooling in the vicinity of the axial end portion can be given priority over the vicinity of the axial central portion of the image carrier.

  According to the present invention of claim 5, in addition to the effect obtained by the invention of claim 2, the periphery of the fixing device can be cooled.

  According to the sixth aspect of the present invention, in addition to the effect obtained by the fifth aspect of the invention, the periphery of the fixing device can be effectively cooled.

1 is a schematic view of an image forming apparatus according to an embodiment of the present invention. 1 is a schematic view of an image forming unit according to an embodiment of the present invention. 1 is a schematic view of a fixing device and its peripheral structure according to an embodiment of the present invention. FIG. 3 is a cross-sectional view from the left side surface excluding the fixing device according to the embodiment of the present invention. FIG. 2 is a cross-sectional view of the vicinity of the front side of the image forming apparatus main body according to the embodiment of the present invention. FIG. 3 is a perspective view illustrating a first air intake unit and a second air intake unit according to an embodiment of the present invention corresponding to the arrangement in the image forming apparatus main body. It is a perspective view of the inflow duct part which concerns on embodiment of this invention. FIG. 2 is a perspective view around the upper surface of the image forming apparatus main body according to the embodiment of the present invention. It is a perspective view of a discharge duct part and an introduction duct part concerning an embodiment of the present invention. FIG. 3 is an explanatory diagram viewed from above explaining the air flow in the image forming apparatus main body according to the embodiment of the present invention. It is explanatory drawing which looked at the flow of the air around the fixing device and air guide part which concerns on embodiment of this invention from the front side.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of an image forming apparatus 10 as an embodiment of the present invention.
Hereinafter, the horizontal direction (left and right direction in FIG. 1) of the image forming apparatus 10 is the X direction, the horizontal direction (front and rear (depth) direction in FIG. 1) orthogonal to the X direction is the Y direction, and the X direction and the Y direction are orthogonal. The vertical direction (up and down direction in FIG. 1) is described as the Z direction.

  The image forming apparatus 10 includes a recording medium supply unit 12 that is provided at a lower portion and supplies a recording medium P, a document reading unit 14 that is provided at an upper portion and reads a document D, and image information read by the document reading unit 14 or And an image formation processing unit 16 that performs image formation processing on the recording medium P based on image information input from an external device.

  The recording medium supply unit 12 includes, for example, one recording medium storage unit 22 that stores the recording media P in a stacked state, a sending roll 24 that sends out the recording medium P stored in the recording medium storage unit 22, and the recording medium P And a conveyance roll 26 for conveying the sheets one by one.

  The document reading unit 14 includes a document transport device 34 that automatically transports the document D placed on the document placement table 32, a platen member 36 that is provided below the document transport device 34 and on which the document D is placed, A reader 38 is provided so as to be movable in the X direction, and irradiates the document D with light and reads the document D based on the reflected light from the document D.

  The document transport device 34 includes a delivery roll 40 that feeds the documents D one by one, an automatic transport path 42, and a document discharge table 44 that discharges the read document D. The automatic conveyance path 42 is provided with, for example, five conveyance rolls 46a, 46b, 46c, 46d, and 46e for conveying the document D. A part of the automatic conveyance path 42 is on the platen member 36 (reading position). ).

  The reading device 38 reads the document D conveyed by the document conveying device 34 in a state stopped at the left end side of the platen member 36, and moves the document D placed on the platen member 36 in the X direction. It is supposed to read.

  The image forming processing unit 16 includes an image forming apparatus main body 50, and the image forming apparatus main body 50 includes an image forming unit 52, a main conveyance path 54, a first air intake unit 56, and a second air intake unit. 58 is provided.

On the upper part of the image forming apparatus main body 50, an upper surface 50a which is an upward surface of the image forming apparatus main body 50 and a part of the left side is curved, and a YZ surface erected by being connected to the upper surface 50a and the lower end portion. A first side wall 50b, and a second side wall 50c that is an XZ plane that is orthogonal to the first side wall 50b and is erected on the far side in the Y direction. A side wall inlet 50d is formed in the second side wall 50c.
At least the upper surface 50a and the first side wall 50b constitute a discharge space 60 from which the recording medium P is discharged.

  The image forming apparatus main body 50 is provided with a reversing conveyance unit 62 that reverses the recording medium P when forming images on both sides of the recording medium P. A gap 64 is formed between the image forming apparatus main body 50 and the reverse conveyance unit 62, and outside air flows into the image forming apparatus main body 50 from the gap 64.

  The image forming unit 52 includes an image forming unit 70 including an image holding member 68, and a latent image forming apparatus that irradiates the image holding member 68 of the image forming unit 70 with light and forms a latent image on the surface of the image holding member 68. 72, a transfer device 74 that transfers the developer image formed by the image forming unit 70 to the recording medium P, and a fixing device 76 that fixes the developer image transferred to the recording medium P by the transfer device 74 to the recording medium P. And have.

  A shutter member 78 that moves between a position that covers the image carrier 68 of the image forming unit 70 and a position that exposes the image carrier 68 is provided above the image forming unit 70.

  For example, the latent image forming apparatus 72 has a configuration in which a semiconductor laser, a polygon mirror, an imaging lens, and a plurality of mirrors (all not shown) are provided in the main body of the latent image forming apparatus. Thereby, the light emitted from the semiconductor laser is deflected and scanned by the polygon mirror, and is irradiated as the exposure light L on the outer peripheral surface of the image carrier 68 through the imaging lens and the mirror, so that the surface of the image carrier 68 is irradiated. An electrostatic latent image corresponding to the image information is formed.

The transfer device 74 is provided at a position facing the image carrier 68 of the image forming unit 70 so as to rotate in a direction opposite to the image carrier 68 and has a polarity opposite to that of the developer (for example, minus). The voltage is supplied from a power supply unit (not shown).
The inside of the image carrier 68 is grounded, and a potential difference is generated between the surface of the image carrier 68 and the transfer device 74 by supplying power to the transfer device 74. Due to this potential difference (electric field), the developer image present on the surface of the image carrier 68 is transferred onto the recording medium P.

  The fixing device 76 transfers the developer image onto the recording medium P on which the developer image has been transferred by the transfer device 74.

  The main conveyance path 54 is a conveyance path that conveys the recording medium P supplied from the recording medium supply unit 12 toward the discharge space 60. In the main conveyance path 54, in order from the upstream side in the conveyance direction of the recording medium P, a registration roll 80, a transfer device 74, a fixing device 76, a first discharge unit 82 that is a discharge roll, a conveyance roll 84, A second discharge unit 86 that is a discharge roll is disposed.

  The registration roll 80 temporarily stops the recording medium P and supplies it to the transfer device 74 at a predetermined timing.

The first discharge unit 82 is provided below the second discharge unit 86, and discharges the recording medium P on which the developer image is fixed by the fixing device 76 to the discharge space 60. The recording medium P discharged into the discharge space 60 is stacked on the stacking portion that is the upper surface 50a of the image forming apparatus main body 50 described above.
The transport roll 84 transports the recording medium P from the fixing device 76 to the second discharge unit 86.
The second discharge unit 86 discharges the recording medium P on which the developer image is fixed by the fixing device 76 to the discharge space 60. The recording medium P discharged into the discharge space 60 may be stacked on the stacking portion that is the upper surface 50a of the image forming apparatus main body 50 described above. However, the first discharge portion 82 and the second discharge portion 86 are used. The second stacking portion is provided so as to divide the discharge space into the upper and lower positions so that the recording medium discharged by the second discharge portion 86 is stacked on the second stacking portion. Good.
When images are formed on both sides of the recording medium P, the second discharge unit 86 rotates in the opposite direction to that when the recording medium is discharged into the discharge space 60, and the recording medium P on which one side has an image formed. Is conveyed from the rear end portion to the reverse conveyance unit 62 via the conveyance roll 84.

  As described above, the recording medium P on which the developer image is fixed by the fixing device 76 is discharged to the stacking portion by the first discharge portion 82 or the second discharge portion 86.

The reversal conveyance unit 62 is provided with a reversal conveyance path 92 connected to the main conveyance path 54 with one end downstream from the fixing device 76 and the other end upstream from the registration roll 80.
The reverse conveyance path 92 reverses the recording medium P on which an image is formed on one surface and conveys the recording medium P toward the upstream side of the resist roll 80 again. In the reverse conveyance path 92, for example, two reverse conveyance rollers 94a and 94b are arranged.

In the image forming apparatus main body 50, a toner cartridge 100 containing, for example, a black (K) developer image supplied to the image forming unit 70 is detachably provided above the latent image forming apparatus 72.
In the image forming apparatus main body 50, a high voltage power supply unit 102 is provided below the latent image forming apparatus 72. Further, a wall portion 104 is provided on the right side of the first intake portion 56, and a low voltage power supply portion 106 is provided on the opposite side of the first intake portion 56 with respect to the wall portion 104. .
The high voltage power supply unit 102 and the low voltage power supply unit 106 function as a power supply source for each unit of the image forming apparatus 10.

  The first intake section 56 is installed so that at least the center thereof is higher than the installation height of the latent image forming apparatus 72 (the upper end of the latent image forming apparatus 72). The air flowing in the forming apparatus main body 50 flows above the latent image forming apparatus 72.

Next, details of the image forming unit 70 will be described.
FIG. 2 shows a schematic diagram of the image forming unit 70.

The image forming unit 70 includes a photosensitive member cartridge 112, a developing cartridge 114 disposed below the photosensitive member cartridge 112, and a shutter member 78.
The exposure light L emitted from the latent image forming device 72 passes through the path 116 formed by the bottom wall of the photosensitive cartridge 112 and the upper wall of the developing cartridge 114, and then the image holding body 68 of the photosensitive cartridge 112. The outer peripheral surface is irradiated.

The photoconductor cartridge 112 has a photoconductor cartridge main body 112a.
In the photoreceptor cartridge main body 112a, an image holding body 68 provided to rotate in the direction of the arrow + R (clockwise direction in FIG. 2) and a power source (in contact with the outer peripheral surface of the image holding body 68) A charging roll 122 that charges the image carrier 68 by a potential difference generated by a voltage applied by an unillustrated), an erase lamp 124 that irradiates light to the outer peripheral surface of the image carrier 68 after transfer, and after irradiation of the erase lamp 124 And a cleaning member 126 for cleaning the outer peripheral surface of the image holding member 68.

  A sub-developer supply unit 130 is provided on the right side of the cleaning member 126. The sub-developer supply unit 130 is connected to the toner cartridge 100, and a developer image is supplied from the toner cartridge 100.

  On the side wall of the sub-developer supply unit 130, a protrusion 132 is provided that extends in a direction orthogonal to the axial direction of the image carrier 68. By inserting the protrusion 132 into a cartridge receiving portion (not shown) of the image forming apparatus 10, the image forming unit 70 is mounted in the image forming apparatus 10.

  The developing cartridge 114 is provided with a developing roll 140 that develops the electrostatic latent image formed on the surface of the image carrier 68 by the latent image forming device 72 using a developer.

  Below the developing roll 140, there are provided a first conveying member 144 and a second conveying member 146 that diffuse the developer accommodated in the developer accommodating chamber 142 while being conveyed in the axial direction.

  A developer supply unit 148 is provided on the right side of the developing roll 140, and the developer supply unit 150 provided between the developer storage chamber 142 and the developer supply unit 148 rotates to supply the developer. The developer is supplied from the unit 148 to the developer storage chamber 142.

The developer supply unit 148 is supplied with developer from the sub-developer supply unit 130 via a supply pipe (not shown).
By a motor (not shown), the first transport member 144 and the supply member 150 rotate in the −R direction (counterclockwise direction in FIG. 2), and the second transport member 146 rotates in the + R direction.

  The developer supplied from the first transport member 144 and the second transport member 146 adheres to the outer peripheral surface of the developing roll 140 and is transported to a position facing the image carrier 68 by the rotation of the developing roll 140. The The electrostatic latent image formed on the surface of the image carrier 68 is visualized as a developer image by the developer on the developing roll 140.

The shutter member 78 is in a −S direction (counterclockwise direction in FIG. 2) between a position covering the image holding body 68 and a position exposing the image holding body 68 (open state) with respect to the photoconductor cartridge main body 112a. ) And + S direction (clockwise direction in FIG. 2).
The shutter member 78 covers the surface of the image holding body 68 when the image forming unit 70 is detached from the image forming apparatus 10, and the surface of the image holding body 68 when the image forming unit 70 is attached to the image forming apparatus 10. It is exposed toward the main conveyance path 54.
The shutter member 78 is arranged between the photoreceptor cartridge 112 and the fixing device 76 in a state where the image forming unit 70 is mounted on the image forming apparatus 10 and the image holding member 68 is exposed.

  The shutter member 78 is provided so as to move in the + S direction and the −S direction by a guide member (not shown), for example, and is configured to be urged in a direction to cover the image holding body 68 by an urging means such as a spring. The Then, a projection that comes into contact with the shutter member 78 is provided on the image forming apparatus main body 50 side of the image forming apparatus 10, and the shutter member 78 is brought into contact with the projection when the image forming unit 70 is mounted. A mechanism for moving the image holding member 68 in the direction in which the image holding member 68 is exposed is included.

As shown in FIG. 3, the fixing device 76 has a fixing device main body 76 a, and is disposed inside the fixing device main body 76 a on the developer image surface side on the recording medium P, and includes a heating rotator provided with a heater therein. And a pressure roll 164 as a pressure rotator which is disposed to face the surface of the heat roll 162 and pressurizes the recording medium P toward the heat roll 162.
The fixing device 76 heats and presses the recording medium P by sandwiching the recording medium P between the heating roll 162 and the pressure roll 164 to fix the developer image on the recording medium P.

  Between the fixing device 76 and the transport roll 84 in the main transport path 54, a first switching member 184 and a second switching member disposed on the downstream side in the recording medium transport direction from the first switching member 184. 186 is provided.

The first switching member 184 is provided to be rotatable about the shaft portion 184a, and the second switching member 186 is provided to be rotatable about the shaft portion 186a.
The first switching member 184 and the second switching member 186 are formed, for example, with a gap (in a comb shape) so as to pass each other in the X direction.

  When the recording medium P is conveyed from the fixing device 76 to the first discharge unit 82, the first switching member 184 and the second switching member 186 are in the positions indicated by the solid lines, and the recording medium P is the first switching member. It passes through the right side of the member 184 and the second switching member 186, is guided by a recording medium guide unit 182 described later, and is conveyed to the first discharge unit 82.

  When the recording medium P is conveyed from the fixing device 76 to the second discharge unit 86, the first switching member 184 and the second switching member 186 move to the positions indicated by the two-dot chain line. Accordingly, the recording medium P passes through the right side of the first switching member 184 and the left side of the second switching member 186 and is conveyed to the second discharge unit 86.

  For example, when the recording medium P is transported from the second discharge unit 86 to the reverse transport path 92 as in duplex printing, the first switching member 184 and the second switching member 186 move to the positions indicated by the solid lines. To do. As a result, the recording medium P passes through the left side of the first switching member 184 and the second switching member 186 via the transport roll 84, and is guided by the second transport guide unit 188 to the reverse transport path 92. Be transported.

  As shown in FIG. 4, the support (frame) 170 is disposed between the first side surface 50b of the image forming apparatus main body 50 and the fixing apparatus main body 76a with a gap therebetween. The support 170 is made of a material having excellent strength, such as stainless steel, and both ends of the support 170 are fixed to the side surfaces of the image forming apparatus main body 50 and function as reinforcing members that reinforce the image forming apparatus main body 50. At the same time, it functions as a heat-resistant member that protects surrounding components from the heat generated by the fixing device 76. The support 170 is formed so as to cover the periphery of the fixing device 76 on the right side of FIG. Further, a positioning portion 330 is formed on the support 170, and a part of the fixing device main body 76 a is fitted into the positioning portion 330, the fixing device 76 is positioned, and the fixing device is supported by the support 170. .

A notch 332 is formed in the upper part of the support 170, and a recording medium guide 182 is provided in the notch 332. The recording medium guide unit 182 constitutes a part of the main conveyance path 54 from the fixing device 76 to the first discharge unit 82. The recording medium guide portion 182 is composed of a number of plate-like members, and the lower end of the recording medium guide portion 182 is fixed to the upper end of the notch portion 332. The space between the recording medium guides 182 is opened to form an air passage.
In this embodiment, the recording medium guide unit 182 is composed of a number of plate-shaped members. However, the present invention is not necessarily limited to this, and the number of recording medium guide units 182 may be one. Alternatively, for example, a hole may be formed in the recording medium guide part 182 of one air passage to form an air passage.

The support 170 is further formed with a large number of air holes 334. The air hole 334 connects the gap between the fixing device main body 76 a and the support 170 and the gap between the support 170 and the first side surface 50 b of the image forming apparatus main body 50. Ambient air passes toward the air guides 242 and 244. The vent hole 334 is formed to be deviated from the center in FIG. 4 to the right side, and the left side is a wall, and the wall constitutes the first ventilation prevention part 336. The first ventilation prevention unit 336 corresponds to a first intake opening 252 of a first air guide unit 242 of a second intake unit 58 to be described later, and the second intake unit from the vicinity of the discharge units 56 and 86. The ventilation to 58 is prevented. On the other hand, the left side portions of the large number of air holes 334 are formed, for example, in parallel so as to correspond to the longitudinal direction of a second intake opening 254 described later. The air can easily flow into the second intake portion 58 through the air.
In this embodiment, a large number of vent holes 334 are formed. However, the present invention is not necessarily limited to this. For example, the vent holes 334 are formed as one elongated hole extending in the longitudinal direction of the support 170. Also good.

  The vicinity of the discharge portions 56 and 86 and the second intake portion 58 are between the recording medium guide portion 182 of the notch portion 332 and between the first side surface 50b of the image forming apparatus main body 50 and the support 170. And the fixing device main body 76a and the support 170, and through the air holes 334 so as to allow ventilation. As a result, air in the vicinity of the discharge portions 56 and 86 whose humidity has been increased by the vapor discharged from the recording medium is sucked into the second intake portion 58, and condensation of the discharge portions 56 and 86 is prevented.

Next, the configuration of the front side of the image forming apparatus main body 50 will be described.
FIG. 5 is a sectional view of the vicinity of the front side of the image forming apparatus main body 50.

A front cover 202 is provided on the front side (the front side in the Y direction) of the image forming apparatus main body 50 so as to be freely opened and closed. The front cover 202 is opened and closed when the toner cartridge 100 is attached and detached.
An opening 202 a penetrating in the Z direction is formed at the lower end of the front cover 202, and outside air flows into the front cover 202 from the gap between the bottom surface of the front cover 202 and the top surface of the recording medium supply unit 12. It is supposed to be.
An inner cover 204 is provided inside the front cover 202 of the image forming apparatus main body 50.

  The inner cover 204 is formed in a hollow rectangular parallelepiped shape, and a plurality of louvers 206 that communicate the inside and outside of the inner cover 204 are formed at the lower part of the front wall 204a on the front cover 202 side of the inner cover 204. Yes. Louver 206 has a plurality of slits 206a.

On the front wall 204 a of the inner cover 204, ribs 208 are formed so as to protrude in the Y direction to the front cover 202, and a plurality of louvers 206 are surrounded by the ribs 208.
As a result, the outside air flowing in from the opening 202 a passes through the plurality of louvers 206 and flows into the inner cover 204.

An opening 210 that opens toward the inside of the image forming apparatus main body 50 is formed on the upper portion of the rear wall 204 b that is disposed to face the front wall 204 a of the inner cover 204.
A first intake portion 56 is provided in the opening 210. Specifically, the first intake fan 212 of the first intake unit 56 is attached to the periphery of the opening 210 with screws. As a result, when the first intake fan 212 is activated to perform intake air, outside air flows from the opening 202a of the front cover 202 into the opening 210 via the louver 206 of the inner cover 204, and the first air Outside air is blown into the image forming apparatus main body 50 through the blower duct 214 of the intake section 56.

Next, the details of the second intake part 58 will be described.
FIG. 6 is a perspective view showing the first air intake portion 56 and the second air intake portion 58 corresponding to the arrangement in the image forming apparatus main body 50.
FIG. 7 shows a perspective view of the inflow duct portion 220.
FIG. 8 shows a perspective view around the upper surface 50a.
FIG. 9 is a perspective view of the discharge duct part 222 and the introduction duct part 226.

As shown in FIG. 6, the second intake portion 58 is disposed on the left back side of the first intake portion 56.
The second intake portion 58 is arranged in line with the end portion in the X direction of the shutter member 78 in the open state, and an inflow duct portion 220 into which air flows, and an exhaust duct disposed at the back side of the inflow duct portion 220. Portion 222, a second intake fan (intake means) 224 for sucking air in the discharge duct portion 222 to the outside, and air in the discharge space 60 is discharged through the side wall inlet 50d (see FIG. 1). The duct part 222 is introduced into the duct part 222, and the exhaust cover 228 is attached to a back panel provided on the back side of the image forming apparatus main body 50.
The exhaust cover 228 is provided with an odor filter 230 for removing the odor of air discharged to the outside of the image forming apparatus main body 50 through the discharge duct portion 222 and the introduction duct portion 226.

First, the inflow duct part 220 will be described.
The inflow duct portion 220 has a bottom plate 232 that is an XY surface formed in a trapezoidal shape in plan view from the shutter member 78 in an open state toward the discharge duct portion 222. Side walls 234a and 234b are erected on both ends of the upper surface of the bottom plate 232 so as to extend upward in the Z direction along the outer edge. A partition wall 236 is erected on the upper surface of the bottom plate 232 at the approximate center between the side wall 234a and the side wall 234b.

  By disposing the upper surface 50a of the image forming apparatus main body 50 above the bottom plate 232, the first air guide portion 242 and the second air guide portion 244 are formed with the partition wall 236 interposed therebetween.

  Specifically, the first air guide portion 242 includes a bottom plate 232 disposed on the lower side in the Z direction and a side wall 234a disposed on the rear side in the Y direction as viewed from the direction of air flow (arrow A in FIG. 6). A partition wall 236 disposed on the front side in the Y direction with respect to the side wall 234a, an upper surface partition wall 246 that protrudes downward from the upper surface 50a and abuts against the upper end of the partition wall 236, and on the upper side in the Z direction. It has a cylindrical configuration surrounded by the arranged upper surface 50a.

The first air guide portion 242 is formed in an L shape in a plan view (XY plane).
At the end of the first air guide 242 on the shutter member 78 side, a first intake opening 252 that is an intake port for sucking air is formed, and is opposite to the first intake opening 252. A first suction portion 262 that is a suction port is formed at the end portion on the side (the discharge duct portion 222 side).

  The second air guide portion 244 includes a bottom plate 232 disposed on the lower side in the Z direction and a partition wall 236 and an upper surface partition wall disposed on the back side in the Y direction as viewed from the air flow direction (arrow A in FIG. 6). 246, a side wall 234b disposed on the front side in the Y direction with respect to the partition wall 236 and the upper surface partition wall 246, an upper surface side wall 248 that protrudes downward from the upper surface 50a and abuts against an upper end portion of the side wall 234b, It has a cylindrical configuration surrounded by an upper surface 50a disposed on the upper side in the Z direction.

  The 1st air guide part 242 and the 2nd air guide part 244 become the structure partitioned off over the full length by the partition member 270 comprised by the partition wall 236 and the upper surface partition wall 246. FIG.

The second air guide portion 244 is formed in an L shape in plan view.
At the end of the second air guide portion 244 on the shutter member 78 side, a second intake opening 254 that is an absorption port for sucking air is formed, and is opposite to the second intake opening 254. A second suction portion 264 that is a suction port is formed at the end portion on the side (the discharge duct portion 222 side).
The first air intake opening 252 and the second air intake opening 254 are opened between the fixing device 76 and the image carrier 68, and as will be described later, around the fixing device 76 and the image carrier 68. It can be inhaled from both sides.

  As described above, the second air guide portion 244 is formed in an L shape outside the first air guide portion 242, and the flow between the first air guide portion 242 and the second air guide portion 244 is determined. The length of the road is different.

Here, the image carrier 68 is moved from the back side in the rotation axis direction (Y direction) to the back side end region W1, the center region W2 disposed in front of the back side end region W1, and the center region W2. When divided into three regions, a front side end region W3 arranged on the front side, the first intake opening 252 is arranged to face the back side end region W1.
Similarly, the second intake opening 254 is disposed so as to face the central region W2.
The inflow duct portion 220 is not provided at a position facing the front end region W3, and a second sealing member 284 described later is provided.

  Note that the position of the partition member 270 in the Y direction is determined in consideration of the amount of cooling air at a portion where cooling is required in the rotation axis direction (Y direction) of the heating roll 162, for example.

In this embodiment, the partition member 270 has a ratio of the opening area of the first intake opening 252 and the opening area of the second intake opening 254 such that the opening area of the first discharge port 262 and the second discharge opening 254 are the same. It is provided at a position similar to the ratio to the opening area of the outlet 264.
For this reason, the balance of the amount of air flowing through the first air guide portion 242 and the second air guide portion 244 is kept better than in the case where this configuration is not provided. In addition, the amount of air flowing through the first air guide portion 242 and the second air guide portion 244 can be easily controlled as compared with the case where this configuration is not provided.

  The first air guide 242 and the second air guide 244 are configured to be partitioned by the partition member 270, so that the first intake opening 252 and the second air guide 252 and second Unevenness of the suction force (air volume) generated in the intake opening 254 is suppressed (when the partition member 270 is not provided, a portion where the suction force increases is determined as a predetermined portion).

  The sealing member 272 closes a gap formed between the shutter member 78 and the upper surface 50a. The sealing member 272 includes a first sealing member 282 that faces the back-side end region W1 and the center region W2, and a second sealing member 284 that faces the front-side end region W3.

The first sealing member 282 is attached to a rib 232a (see FIG. 10) protruding downward from the lower surface of the bottom plate 232 of the inflow duct portion 220 with, for example, an adhesive.
The second sealing member 284 is attached to a rib (not shown) protruding downward from the upper surface 50a with, for example, an adhesive.

  Each of the first sealing member 282 and the second sealing member 284 is formed of, for example, a rectangular parallelepiped polyurethane foam. Each of the first sealing member 282 and the second sealing member 284 is arranged so as to come into contact with the end of the shutter member 78 and elastically deform when the shutter member 78 is in an open state.

As shown in FIG. 8, the second ventilation prevention portion 172 is formed as a rib on the back surface side of the first side surface 50 b at a position corresponding to the upper side of the first intake opening 252. The second ventilation preventing portion 172 is longer than the first intake opening 252 in the Y direction, and is provided so as to cover the first intake opening 252 in the Y direction.
The second draft prevention unit 172 reduces the amount of air from the upper direction toward the first intake opening 252 in the Y direction to be smaller than the amount of air toward the second intake opening 254, and the image carrier. The amount of air from the end of 68 toward the first intake opening 252 is increased.

  Next, the discharge duct part 222 and the introduction duct part 226 will be described.

  As shown in FIG. 9, the discharge duct part 222 is connected to the inflow duct part 220 and the introduction duct part 226. The discharge duct 222 is connected to the first air guide portion 242 connected to the first air guide portion 242 and the introduction duct portion 226 of the inflow duct portion 222 and the second air guide portion 244 of the inflow duct portion 220. The second discharge guide portion 304 is provided.

  As a result, when the second intake fan 224 is moved, the air flowing into the discharge duct portion 222 from the first air guide portion 242 and the introduction duct portion 226 is discharged to the outside through the first discharge guide portion 302. In addition, the air that has flowed from the second air guide portion 244 into the discharge duct portion 222 is discharged to the outside via the second discharge guide portion 304.

The first discharge guide portion 302 includes a bottom plate 306 disposed on the lower side in the Z direction as viewed from the air flow direction (arrow B in FIG. 8), and a side wall erected on the left end portion in the X direction of the bottom plate 306. It has a cylindrical configuration surrounded by 308a, a partition wall 310 erected substantially at the center of the bottom plate 306, and an upper wall 312 disposed on the upper side in the Z direction and inclined at the same inclination angle as the upper surface 50a. .
The partition wall 310 is higher (longer in the Z direction) than the side wall 308 a in accordance with the inclination of the upper wall 312.

The second discharge guide portion 304 includes a bottom plate 306 disposed on the lower side in the Z direction, a partition wall 310 disposed on the left side in the X direction, and the bottom plate 306 as viewed from the direction of air flow (arrow B in FIG. 8). It has a cylindrical configuration surrounded by a side wall 308b erected on the right end in the X direction and an upper wall 312 disposed on the upper side.
The side wall 308b is higher (longer in the Z direction) than the partition wall 310 in accordance with the inclination of the upper wall 312.

The introduction duct portion 226 includes a cylindrical portion 320 extending in the Z direction from the upper surface of the discharge duct portion 222, and an introduction port 322 opened in a vertically long rectangular shape toward the front side in the Y direction at the upper end of the cylindrical portion 320. A side wall inlet 50d formed in the second side wall 50c is disposed on the front side in the Y direction of the inlet 322.
Accordingly, when the second intake fan 224 is moved, the air in the exhaust space 60 flows into the introduction duct portion 226 from the introduction port 322 through the side wall introduction port 50d.

  Next, an outline of the air flow in the image forming apparatus main body 50 will be described.

FIG. 10 is an explanatory view of the air flow in the image forming apparatus main body 50 as viewed from above.
FIG. 11 is an explanatory view of the air flow around the fixing device 76 and the first air guide 242 as seen from the front side. FIG. 10 is a schematic view on the XZ plane passing through the first intake opening 252.

  As an example of the flow of air flowing from the gap 64, the first intake section 56, the first discharge section 82, and the second discharge section 86 of the image forming apparatus main body 50 to the second intake section 58, a path F1 , F2, F3, F4, F5.

  The path F1 passes from the gap 64 of the image forming apparatus main body 50 to the periphery of the fixing device 76, passes between the fixing device 76 and the shutter member 78, and the first air guide portion 242 and the first discharge guide portion. This is a flow through 302 and discharged from the image forming apparatus main body 50 to the outside.

The path F2 passes between the toner cartridge 100 and the latent image forming device 72 from the first air intake portion 56, passes through the lower side of the inflow duct portion 220 and the shutter member 78, and turns around from the left side in the X direction. The flow passes through the upper side of the member 78 and joins the path F1 or the path F2 and is discharged from the exhaust cover 228 to the outside of the image forming apparatus main body 50.
The air in the vicinity of the image carrier 68 (for example, air whose temperature has been increased by the heating roll 162) passes through the first air guide unit 242 and the second air guide unit 244 through the path F1 and the path F2, and the image forming apparatus. It is discharged outside the main body 50.

  A path F <b> 3 is a flow that passes from the first air intake portion 56 to the periphery of the toner cartridge 100, passes through the periphery of the second air intake portion 58, and is discharged to the outside of the image forming apparatus main body 50.

  The path F4 extends from the first discharge unit 82 and the second discharge unit 86 to the recording medium guide unit 182 of the notch 332 and between the first side surface 50b of the image forming apparatus main body 50 and the support 170. The flow is discharged from the image forming apparatus main body 50 to the outside through the inflow duct portion 220 and the discharge duct portion 222.

  The path F5 passes from the first discharge unit 82 and the second discharge unit 86, between the fixing device main body 76a and the support 170, through the vent hole 334, and through the inflow duct unit 220 and the discharge duct unit 222. The flow is discharged from the image forming apparatus main body 50 to the outside.

Here, a second ventilation prevention portion 172 is provided above the first intake opening 252 of the first air guide portion 242, and the second ventilation prevention portion 172 is provided from the routes F5 and F6. The ventilation to the 1st air guide part 242 is prevented.
For this reason, with respect to the first air guide portion 242, the air flow in the paths F <b> 4 and F <b> 5 is prevented by the second airflow prevention portion 172 in combination with the first airflow prevention portion 336 described above. When the air flow in the paths F4 and F5 is reduced or interrupted, the intake force of the first intake opening 252 is directed toward the air in the paths F1 and F2.
Therefore, the first air guide portion 242 is easier to inhale the air flowing in the paths F1 and F2 than in the paths F4 and F5.

For example, when a heat source such as a drive motor is provided only on one side in the axial direction of the image carrier 68, it is necessary to particularly enhance the cooling effect on one side.
Since a heat source such as a drive motor is provided on the back side end region W1 side, the temperature on the back side end region W1 side is likely to rise compared to the central region W2 and the front side end region W3. Become. In this case, in the back end region W1, the air flow in the routes F1 and F3 is promoted more than the route F5, so that the back end region W1 side of the image carrier 68 is in the central region W2 and the near side. It becomes easier to cool than the end region W3.

  In the above-described embodiment, the first ventilation prevention unit 336 and the second ventilation prevention unit 172 have been described with respect to the configuration provided above the first air guide unit 242, but the present invention is not limited to this, and cooling is performed. It can be changed as appropriate in consideration of the required cooling air volume at the site.

  The shape of the second ventilation prevention portion 172 is not limited to a plate shape, and may be a “U” shape covering the upper side in the Z direction, the rear side in the Y direction, and the near side of the first intake opening 252.

  In the above embodiment, the configuration in which the first air guide portion 242 and the second air guide portion 244 are provided in the inflow duct portion 220 has been described. However, the present invention is not limited thereto, and three or more air guide portions are provided. It may be.

  In addition, by inserting the partition wall 236 and the upper surface partition wall 246 that partition the first air guide part 242 and the second air guide part 244 into the groove part (not shown), the base end part is inserted into the bottom plate 232 and the upper surface 50a. You may make it fix.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Recording medium supply part 14 Original reading part 16 Image formation process part 22 Recording medium accommodating part 24 Sending roll 26 Conveying roll 32 Original placing stand 34 Original conveying apparatus 36 Platen member 38 Reading apparatus 40 Sending roll 42 Automatic conveyance path 44 Conveying roll 50 Image forming apparatus main body 50a Upper surface 50b Side wall 50c Side wall 50d Side wall inlet 52 Image forming unit 54 Main conveying path 56 First air intake unit 58 Second air intake unit 60 Discharge space 62 Reverse conveyance unit 64 Gap 68 Image holding Body 70 Image forming unit 72 Latent image forming device 74 Transfer device 76 Fixing device 78 Shutter member 80 Registration roll 82 First discharge unit 84 Transfer roll 86 Second discharge unit 92 Reverse transfer path 94a Reverse transfer roll 100 Toner cartridge 102 High Voltage power supply unit 104 Wall unit 106 Low voltage power supply unit 112 Optical cartridge 112a Housing 114 Developer cartridge 116 Path 122 Charging roll 124 Erase lamp 126 Cleaning member 130 Sub-developer supply unit 132 Protrusion 140 Development roll 142 Developer storage chamber 144 Transport member 146 Transport member 148 Developer supply unit 150 Supply member 162 Heating roll 164 Pressurizing roll 170 Auxiliary member 172 Second ventilation prevention unit 182 First conveyance guide unit 184 First switching member 184a Shaft unit 186 Second switching member 186a Shaft unit 188 Second conveyance guide unit 202 Front cover 202a Opening 204 Inner cover 204a Front wall 204b Rear wall 206 Louver 206a Slit 208 Rib 210 Opening 212 First intake fan 214 Air duct 220 Inflow duct part 222 Exhaust duct part 22 4 Second intake fan 226 Introduction duct portion 228 Exhaust cover 230 Odor filter 232 Bottom plate 232a Rib 234a Side wall 234b Side wall 236 Partition wall 242 First air guide portion 244 Second air guide portion 246 Upper surface partition wall 248 Upper surface side wall 252 First 1 intake opening 254 2nd intake opening 262 1st suction part 264 2nd suction part 270 partition member 272 sealing member 282 first sealing member 284 second sealing member 302 first discharge guide part 304 Second discharge guide portion 306 Bottom plate 308a Side wall 308b Side wall 310 Partition wall 312 Upper wall 320 Tube portion 322 Notch portion 334 Ventilation hole 336 First ventilation prevention portion W1 Back end portion region W2 Central region W3 Front side Edge area

Claims (5)

An image carrier for holding an image to be transferred to a recording medium;
A fixing device for fixing the image to the recording medium onto which the image is transferred from the image carrier;
A fixing device main body for housing the fixing device;
A discharge unit for discharging the recording medium on which the image is fixed by the fixing device;
A stacking unit for stacking the recording medium discharged from the discharge unit;
An intake means for inhaling;
An air guide that has an air intake opening that opens between the image carrier and the fixing device main body, and that guides air from the air intake opening toward the air intake means;
A support for supporting the fixing device main body ,
The support is disposed in a conveyance path for conveying the recording medium between the fixing device main body and the discharge unit, and guides the recording medium on which the image is fixed by the fixing device to the discharge unit, A recording medium guide portion formed with an air passage for passing air to the intake opening, and a ventilation hole that allows air to pass from the discharge portion to the intake opening through the periphery of the fixing device main body. And an image forming apparatus. An image carrier for holding an image to be transferred to a recording medium;
A fixing device for fixing the image to the recording medium onto which the image is transferred from the image carrier;
A fixing device main body for housing the fixing device;
A discharge unit for discharging the recording medium on which the image is fixed by the fixing device;
A stacking unit for stacking the recording medium discharged from the discharge unit;
An intake means for inhaling;
An air guide that opens between the image carrier and the fixing device and guides air from the air intake opening toward the air intake means;
A support for supporting the fixing device main body ,
The air guide part has a first air guide part and a second air guide part,
The support is disposed in a conveyance path for conveying the recording medium between the fixing device main body and the discharge unit, and guides the recording medium on which the image is fixed by the fixing device to the discharge unit, One of the recording medium guide part in which an air passage for passing air to the intake opening part is formed and the amount of air sucked from the discharge part is the first air guide part or the second air guide part is the other. An image forming apparatus comprising a ventilation preventing unit for preventing ventilation so as to be less.   The first air guide has a first intake opening that opens toward an axial end of the image carrier, and the second air guide is an axial center of the image carrier. The image forming apparatus according to claim 2, wherein the image forming apparatus has a second intake opening portion that opens toward the portion. 2. The support body covers the periphery of the fixing device main body through a gap, and air around the fixing device main body is sucked into the air guide portion through the gap and the ventilation hole. The image forming apparatus described.   The image forming apparatus according to claim 4, wherein the ventilation hole is formed corresponding to the intake opening.

Images