JP5674239B2 - 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 capable of suppressing a temperature rise in an image forming apparatus main body corresponding to each part.

  According to the first aspect of the present invention, there is provided an image holding body for holding an image to be transferred to a recording medium, a fixing device for fixing an image on a recording medium to which an image has been transferred from the image holding body, and an image by the fixing device. A discharge portion for discharging the fixed recording medium; a first intake passage for sucking air between the image carrier and the fixing device; and a second intake portion for drawing air from the discharge portion to the fixing device. A first air guide portion connected to the first intake passage and having the first intake opening, and connected to the first intake passage and the second intake passage. A second air guide portion having a plurality of intake openings, and a ventilation prevention portion for preventing wind from passing from the second intake passage to the first air guide portion. The opening opens in one area in the axial direction of the image carrier, and the second intake opening An image forming apparatus which is opened to other areas of the axial direction of the image carrier.

  According to a second aspect of the present invention, the second intake opening is provided closer to the center of the image carrier than the first intake opening with respect to the axial direction of the image carrier. The image forming apparatus according to Item 1.

  The present invention according to claim 3 further includes a frame provided between the fixing device and the first air guide portion and supporting the fixing device, wherein the discharge portion is the first intake air. Provided above the opening in the gravitational direction, and the airflow prevention part is provided between the discharge part and the first intake opening so as to cover the upper side of the first intake opening in the gravitational direction. The image forming apparatus according to claim 1 or 2.

  According to a fourth aspect of the present invention, in the airflow prevention portion, the first intake opening is covered with the upper side in the gravity direction and both sides in the axial direction of the image holding body. The image forming apparatus described.

  The present invention according to claim 5 is the image forming apparatus according to any one of claims 1 to 4, wherein the ventilation preventing portion is provided so as to protrude toward the frame body from the first air guide portion side. .

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the ventilation prevention unit is provided so as to protrude from the frame toward the first air guide unit.

  According to the first aspect of the present invention, it is possible to suppress the temperature rise in the image forming apparatus main body corresponding to each part.

  According to the second aspect of the present invention, it is possible to cool the end side more than the central side in the axial direction of the image holding body as compared with the case where this configuration is not provided.

  According to the third aspect of the present invention, in addition to the effect of the present invention according to the first or second aspect, the image forming apparatus has no effect on other configurations as compared with the case where the present configuration is not provided. The temperature rise in the body can be suppressed corresponding to each part.

  According to the fourth aspect of the present invention, in addition to the effects of the first aspect of the present invention according to any one of the first to third aspects, the temperature rise in the image forming apparatus main body is further reduced as compared with the case without the present configuration. It can be suppressed corresponding to each.

  According to the present invention of claim 5, in addition to the effects of the present invention of any one of claims 1 to 4, the configuration can be simplified as compared to the case without this configuration.

  According to the sixth aspect of the present invention, in addition to the effect of the present invention according to any one of the first to fourth aspects, the configuration can be simplified as compared with the case where the present configuration is not provided.

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. 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. FIG. 2 is a schematic view of the periphery of the upper surface of the image forming apparatus main body according to the embodiment of the present invention as viewed from the left side. 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 1st air guide part which concerns on embodiment of this invention from the front side. It is explanatory drawing which looked at the flow of the air around the fixing device and 2nd air guide part which concerns on embodiment of this invention from the front side. FIG. 6 is a schematic view of an upper surface periphery of an image forming apparatus main body according to a second embodiment as viewed from the left side.

[First Embodiment]
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 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 transported from the transport roll 84 to the discharge space 60.
When images are formed on both sides of the recording medium P, the second discharge unit 86 rotates in the opposite direction to when the recording medium P is discharged into the discharge space 60, and the recording medium on which the image is formed on one side. P 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 from the first discharge portion 82 or the second discharge portion 86 to the discharge space 60.

  A partition plate is provided in the discharge space 60 so as to partition the recording medium P discharged from each of the first discharge portion 82 and the second discharge portion 86, and each of the first discharge portion 82 and the second discharge portion 86 is provided. The recording medium P discharged from the recording medium P may be sorted.

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, for example, so as to move in the + S direction and the −S direction by a guide member (not shown), and is configured to be urged in a direction covering the image holding body 68 by an urging means such as a spring. Is done. 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 carrier 68 in the direction in which it is exposed is mentioned.

Next, details of the fixing device 76 and its peripheral structure will be described.
FIG. 3 shows a schematic diagram of the fixing device 76 and its peripheral structure.

The fixing device 76 has a fixing device main body 76a, and a heating roll 162 as a heating rotator disposed inside the fixing device main body 76a on the developer image surface side on the recording medium P and provided with a heater therein, A pressure roll 164 is accommodated as a pressure rotator that is arranged opposite to 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.

The frame (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. The frame 170 functions as a reinforcing member that reinforces the image forming apparatus main body 50, and also functions as a heat-resistant member that protects surrounding components from the heat generated by the fixing device 76.
The frame 170 is configured to come into contact with a plate-shaped ventilation prevention portion 172 formed on the first side wall 50b.

  A recording medium guide 182 that forms a part of the main conveyance path 54 from the fixing device 76 to the first discharge unit 82 is formed on the upper portion of the frame 170.

  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 moves to the right side and the second switching member 186 moves to the left side (the first switching member 184 and the first switching member 184). The second switching member 186 moves to the position indicated by the solid line). As a result, the recording medium P passes through the right side of the first switching member 184 and the second switching member 186, is guided by the recording medium guide unit 182, 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 moves to the left side, and the second switching member 186 crosses the first switching member 184 and moves to the right side. Move (the first switching member 184 and the second switching member 186 move to a position indicated by a 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 moves to the right and the second switching member 186 is on the left. (Similar to the case of transporting the recording medium P from the fixing device 76 to the first discharge unit 82, the first switching member 184 and the second switching member 186 move to the positions indicated by the solid lines). 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 transported to the reverse transport path 92.

Next, the configuration of the front side of the image forming apparatus main body 50 will be described.
FIG. 4 is a cross-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 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 intake fan 212 is activated to perform intake air, outside air flows from the opening 202 a of the front cover 202 into the opening 210 via the louver 206 of the inner cover 204, and the first intake section 56. The outside air is blown into the image forming apparatus main body 50 through the air duct 214.

Next, the details of the second intake part 58 will be described.
FIG. 5 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. 6 shows a perspective view of the inflow duct portion 220.
FIG. 7 is a perspective view around the upper surface 50a.
FIG. 8 is a schematic view of the periphery of the upper surface 50a as viewed from the left side in the X direction.
FIG. 9 is a perspective view of the discharge duct part 222 and the introduction duct part 226.

As shown in FIG. 5, 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. Part 222, an exhaust fan 224 for exhausting the air in the exhaust duct part 222 to the outside, and an introduction duct part for introducing the air in the exhaust space 60 into the exhaust duct part 222 via the side wall inlet 50d (see FIG. 1). 226 and an exhaust cover 228 attached to a rear 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.
As shown in FIGS. 5 and 6, the inflow duct portion 220 is a bottom plate that is an XY surface formed in a trapezoidal shape in a plan view (XY surface) from the shutter member 78 in an open state toward the discharge duct portion 222. 232. 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 an upper end portion 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).
A first air intake opening 252 for taking in air is formed at the end of the first air guide 242 on the shutter member 78 side, and is opposite to the first air intake opening 252 (exhaust duct). A first suction opening 262 is formed at the end of the 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 a plan view (XY plane).
A second air intake opening 254 for inhaling air is formed at the end of the second air guide 244 on the shutter member 78 side, and is opposite to the second air intake opening 254 (exhaust duct). A second suction opening 264 is formed at the end of the portion 222 side.

  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 FIGS. 7 and 8, the airflow prevention unit 172 has the inflow duct unit 220 (first air guide unit 242) at a position on the first side wall 50 b corresponding to the upper side of the first intake opening 252. It is formed so as to protrude from the side toward the frame body 170. The ventilation member 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 ventilation prevention unit 172 reduces the amount of air from the upper direction toward the first intake opening 252 in the Z direction to be smaller than the amount of air toward the second intake opening 254, and the end of the image carrier 68. The amount of air directed from the portion 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 exhaust fan 224 is moved, the air flowing into the discharge duct unit 222 from the first air guide unit 242 and the introduction duct unit 226 is discharged to the outside through the first discharge guide unit 302. The air flowing from the second air guide portion 244 into the discharge duct portion 222 is discharged to the outside through 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 direction of air flow (arrow B in FIG. 9), 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 in which air flows (arrow B in FIG. 9). 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.
Thus, when the exhaust 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. 11 is a schematic view on the XZ plane passing through the first intake opening 252.
FIG. 12 is an explanatory view of the air flow around the fixing device 76 and the second air guide unit 244 as seen from the front side. FIG. 12 is a schematic view on the XZ plane passing through the second intake opening 254.

  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.

  As illustrated in FIGS. 10 and 11, the path F <b> 1 passes through the periphery of the fixing device 76 from the gap 64 of the image forming apparatus main body 50, passes between the fixing device 76 and the shutter member 78, and passes through the first air. The flow is discharged from the image forming apparatus main body 50 to the outside through the guide unit 242 and the first discharge guide unit 302.

As shown in FIGS. 10 and 12, the path F <b> 2 passes from the gap 64 of the image forming apparatus body 50 to the periphery of the fixing device 76, passes between the fixing device 76 and the shutter member 78, and passes through the second air. The flow is discharged from the image forming apparatus main body 50 to the outside through the guide unit 244 and the second exhaust guide unit 304.
By the path F2, the air near the image carrier 68 (for example, the air in the central region W2 and the front end region W3 whose temperature has been increased by the heating roll 162) passes through the second air guide unit 244 to form an image. It is discharged to the outside of the apparatus main body 50.

As shown in FIGS. 10 to 12, the path F <b> 3 passes between the toner cartridge 100 and the latent image forming device 72 from the first intake portion 56 and passes under the inflow duct portion 220 and the shutter member 78. Thus, the flow passes through the upper side of the shutter member 78 so as to wrap around from the left side in the X direction, merges with 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.
By the path F1 and the path F3, the air in the vicinity of the image holding member 68 (for example, the air in the back end region W1 whose temperature has been increased by the heating roll 162) passes through the first air guide 242 and passes through the first image forming apparatus main body. 50 is discharged outside.

  As shown in FIG. 10, the path F <b> 4 flows from the first suction portion 56 to the outside of the image forming apparatus main body 50 through the periphery of the toner cartridge 100, through the periphery of the second suction portion 58. It is.

As shown in FIG. 12, the path F5 passes from the first discharge part 82 and the second discharge part 86 between the reinforcing member 170 of the fixing device 76 and the first side wall 50b, and the inflow duct part 220 and The flow is discharged from the image forming apparatus main body 50 to the outside through the discharge duct portion 222.
Due to the conveyance of the recording medium P heated by the heating roll 162, for example, in the vicinity of the first unloading section 82 and the second unloading section 86 on the downstream side of the main conveyance path 54 with respect to the recording medium conveyance direction. As a result, water droplets may be generated (condensation). Such water droplets generated in the vicinity of the first carry-out portion 82 and the second carry-out portion 86 are discharged to the outside of the image forming apparatus main body 50 through the inflow duct portion 220 by the path F5.
Further, the air in the discharge space 60 is discharged to the outside of the image forming apparatus 50 through the inflow duct portion 220 by the path F5.

  In the present embodiment, the paths F1, F2, and F3 form a first intake path that sucks in the vicinity of the image carrier 68, and the path F5 allows the vicinity of the first discharge section 82 and the second discharge section 86 to pass. A second intake path for intake is configured.

Here, a ventilation prevention unit 172 is provided above the first intake opening 252 of the first air guide unit 242, and this ventilation prevention unit 172 is provided through the path F5 (second intake path). The ventilation to the 1 air guide part 242 is prevented.
For this reason, about the 1st air guide part 242, the flow of the air of the path | route F5 is prevented by the ventilation prevention part 172 (refer FIG. 11, FIG. 12). When the air flow in the path F5 is reduced or interrupted, the intake force of the first intake opening 252 is directed toward the air in the paths F1 and F3.
Therefore, the first air guide part 242 is easier to inhale the air flowing on the image carrier 68 side (path F1 (path F2) and path F3) than the second air guide part 244.

  As described above, in the back end region W1 where the first intake opening 252 faces, a larger amount of air from the image carrier 68 side is sucked and exhausted than the central region W2 and the front region W3. It is comprised so that.

For example, when a heat source such as a drive motor is provided only on one side of the image holding member 68 in the axial direction, it is necessary to particularly enhance the cooling effect on this one side.
In the present embodiment, a heat source such as a drive motor is provided on the back end region W1 side. For this reason, the temperature on the back side end region W1 side is likely to rise as compared with the central region W2 and the front side end region W3. 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 airflow prevention unit 172 has been described with respect to the configuration provided above the first air guide unit 242. However, the present invention is not limited to this, and the amount of cooling air at a portion where cooling is required is considered. Can be changed as appropriate.

The ventilation prevention unit 172 is not limited to the configuration formed on the first side wall 50b, but may be provided on the frame 170, or may be provided on the fixing device main body 76a.
Further, the airflow preventing portion 172 may be formed integrally with the first side wall 50b, the frame body 170, and the fixing device main body 76a, or may be configured to be detachable as another member.
Further, the airflow prevention unit 172 is not limited to the configuration protruding from the inflow duct unit 220 (first air guide unit 242) side toward the frame body 170, but from the frame body 170 or the fixing device main body 76a to the inflow duct unit 220 side. It is good also as a structure which protrudes toward.

  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.

[Second Embodiment]
Next, a second embodiment will be described.
FIG. 13 is a schematic view of the periphery of the upper surface 50a in the second embodiment as viewed from the left side in the X direction.

In the second embodiment, the ventilation preventing portion 400 is formed on the first side wall 50b. The ventilation prevention unit 400 is formed in 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. The side wall extending in the Z direction of the draft prevention unit 400 extends toward the shutter member 78.
When the ventilation prevention unit 400 is formed in this way, the first air guide unit 242 is more on the image carrier 68 side than the second air guide unit 252 as compared to the case where this configuration is not provided. It becomes easy to inhale the air of the flow from.

Note that the lower end portion of the side wall extending in the Z direction of the ventilation preventing portion 400 may be in contact with the shutter member 78 as long as the movement of the shutter member 78 is not hindered.
Further, a groove portion may be formed in the shutter portion 78, and the shutter portion 78 may be moved in a state where the lower end portion of the side wall extending in the Z direction of the ventilation preventing portion 400 is fitted in the groove portion.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Recording medium supply part 14 Document reading part 16 Image forming process part 50 Image forming apparatus main body 50a Upper surface 50b 1st side wall 50c 2nd side wall 50d Side wall inlet 52 Image forming part 54 Main conveyance path 56 1st Intake portion 58 Second intake portion 60 Discharge space 62 Reverse conveyance unit 64 Clearance 68 Image holding member 70 Image forming unit 72 Latent image forming device 74 Transfer device 76 Fixing device 78 Shutter member 82 First discharge portion 86 Second Discharge unit 92 Reverse conveyance path 170 Frame body 172 Ventilation prevention unit 182 Recording medium guide unit 184 First switching member 186 Second switching member 220 Inflow duct unit 222 Exhaust duct unit 224 Exhaust fan 226 Introduction duct unit 228 Exhaust cover 242 First 1 air guide 244 2nd air guide 252 1st intake opening 254 2nd intake opening 262 First suction opening 264 Second suction opening 270 Partition member 272 Sealing member 302 First discharge guide portion 304 Second discharge guide portion W1 Back end region W2 Central region W3 Front end region

Claims (5)

An image carrier for holding an image to be transferred to a recording medium;
A fixing device for fixing an image on a recording medium onto which the image has been transferred from the image carrier;
A discharge unit for discharging the recording medium on which the image is fixed by the fixing device;
A first air intake path that sucks air between the image carrier and the fixing device;
A second air intake passage for taking in air so as to guide air from the discharge portion to the fixing device;
A first air guide connected to the first intake passage and having a first intake opening;
A second air guide portion connected to the first intake passage and the second intake passage and having a second intake opening;
An airflow prevention unit for preventing wind from passing from the second air intake passage to the first air guide unit;
Have
The first intake opening opens in one area in the axial direction of the image carrier,
The second intake opening opens to another region in the axial direction of the image holding body, and is closer to the center of the image holding body than the first intake opening with respect to the axial direction of the image holding body. An image forming apparatus. A frame body provided between the fixing device and the first air guide portion and supporting the fixing device;
Further comprising
The discharge portion is provided above the first intake opening in the direction of gravity,
The draft protection section, the discharge section and the first intake be between opening image forming apparatus according to claim 1, wherein is provided so as to cover the gravity direction upper side of the first intake opening. 3. The image forming apparatus according to claim 1, wherein the ventilation prevention unit covers the first intake opening with an upper side in a gravity direction and both sides in an axial direction of the image holding member. The image forming apparatus according to claim 2 , wherein the ventilation prevention unit is provided so as to protrude from the first air guide unit side toward the frame body. The image forming apparatus according to claim 2 , wherein the ventilation prevention unit is provided so as to protrude from the frame toward the first air guide unit.

Images