Image forming apparatus

Abstract

The present invention provides an image forming apparatus that can improve the accuracy of the positional arrangement of the first exhaust filter and the second exhaust filter. [Solution] The image forming apparatus 1 comprises a housing 2 having a right side wall 23 with an exhaust port 23a, a fan 71 for exhausting air from inside the housing 2, a first exhaust filter 72 supported by the right side wall 23, and a filter holder 80 that supports a second exhaust filter 75 sized to cover the exhaust port 23a and is detachably attached to the right side wall. The right side wall 23 has a first rib 231 and a third rib 233 as first positioning parts that abut against the first exhaust filter 72 and position the first exhaust filter 72 in a direction along the right side wall, and a louver frame 240 as a second positioning part that abuts against the filter holder 80 and position the filter holder 80 in a direction along the right side wall 23.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] Conventionally, as disclosed in Patent Document 1, there has been known an image forming apparatus including: a housing having an exhaust port; a fan configured to exhaust air inside the housing; and a filter holder attached to the housing and covering the exhaust port of the housing, wherein the filter holder supports a first exhaust filter and a second exhaust filter.

[0003] In an image forming apparatus having a first exhaust filter and a second exhaust filter, a configuration is also conceivable in which the first exhaust filter is supported by the housing, and the second exhaust filter is supported by a filter holder attached to the exterior of the housing.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] As described above, in the configuration where the first exhaust filter is supported by the housing and the second exhaust filter is supported by the filter holder outside the housing, if the arrangement positions of the first exhaust filter and the second exhaust filter are misaligned, air that has passed through the first exhaust filter may be exhausted to the outside without passing through the second filter, and there is a risk that the functions of the respective exhaust filters cannot be sufficiently exhibited.

[0006] Accordingly, the present invention provides an image forming apparatus capable of improving the accuracy of the arrangement positions of the first exhaust filter and the second exhaust filter.

Means for Solving the Problem

[0007] The image forming apparatus that solves the above problems has the following features.

[0008] That is, the image forming apparatus comprises a housing having a side wall with an exhaust port, a fan for exhausting air from inside the housing, a first exhaust filter supported by the side wall, and a filter holder that supports a second exhaust filter having a size that covers the exhaust port and is detachably attached to the side wall, wherein the side wall has a first positioning portion that contacts the first exhaust filter and positions the first exhaust filter in a direction along the side wall, and a second positioning portion that contacts the filter holder and positions the filter holder in a direction along the side wall.

[0009] In this configuration, since the second positioning section for positioning the filter holder supporting the second exhaust filter and the first positioning section for positioning the first exhaust filter are both formed on the side wall of the housing, the accuracy of the positioning of the first and second exhaust filters can be improved. As a result, the functions of the first and second exhaust filters can be fully performed.

[0010] Furthermore, the side wall has an inner protruding wall as a first positioning portion that protrudes inward from the inner surface of the side wall toward the housing, and an outer protruding wall as a second positioning portion that protrudes outward from the outer surface of the side wall toward the housing, the first exhaust filter abuts against the inner protruding wall, and the filter holder abuts against the outer protruding wall.

[0011] In this configuration, since both the outer protruding wall that positions the filter holder supporting the second exhaust filter and the inner protruding wall that positions the first exhaust filter are formed on the side wall of the housing, the accuracy of the positioning of the first and second exhaust filters can be improved. As a result, the functions of the first and second exhaust filters can be fully performed.

[0012] Furthermore, the side wall includes a louver that restricts the direction of exhaust of the air discharged through the exhaust port, and a frame that serves as the outer protruding wall surrounding the outer periphery of the louver.

[0013] This improves the accuracy of the positioning of the filter holder supporting the second exhaust filter relative to the louvers.

[0014] Furthermore, the filter holder comprises a holder housing having a first opening and supporting the second exhaust filter, the frame of the side wall fitting into the first opening, and the inner circumferential surface of the first opening in the holder housing contacting the frame of the side wall.

[0015] This improves the positional accuracy of the filter holder attached to the side wall relative to the louvers, in the direction along the side wall.

[0016] Furthermore, the filter holder has a cover that is detachably attached to the holder housing, the holder housing has a second opening that is closed by the cover attached to the holder housing and opens when the cover is removed from the holder housing, and the second exhaust filter is exposed to the outside of the holder housing through the second opening when the cover is removed from the holder housing.

[0017] This makes it easier to replace the second exhaust filter by removing the cover from the holder housing.

[0018] Furthermore, the frame of the side wall is circular, the first opening of the holder housing is square, and the inner circumferential surface of the first opening in the holder housing has a first surface extending along a first direction which is the direction along the side wall, and a second surface extending along a second direction which is perpendicular to the first direction, and the first surface and the second surface can come into contact with the frame.

[0019] Accordingly, by bringing the first surface and the second surface of the first opening in the holder housing into contact with the frame, the positional accuracy of the holder housing that supports the second exhaust filter relative to the louver can be easily improved.

[0020] Further, the frame of the side wall includes: a first wall extending along a third direction that is a direction along the side wall; and a second wall extending along a fourth direction that is a direction along the side wall and orthogonal to the third direction; the inner peripheral surface of the first opening in the holder housing includes: a third surface extending along the third direction; and a fourth surface extending along the fourth direction; the third surface is capable of contacting the first wall, and the fourth surface is capable of contacting the second wall.

[0021] Accordingly, by bringing the third surface and the fourth surface of the first opening in the holder housing into contact with the first wall and the second wall of the frame on the side wall respectively, the positional accuracy of the holder housing that supports the second exhaust filter relative to the louver can be easily improved.

[0022] Further, the housing accommodates an image forming unit that forms an image on a sheet, the image forming unit includes a drum that forms a toner image on a sheet, a charger that charges the drum, and a fixing device that fixes the toner image formed on the sheet, the first exhaust filter is an ozone decomposition filter capable of decomposing ozone contained in passing air, and the second exhaust filter is a particulate removal filter capable of removing particulates contained in passing air.

[0023] Accordingly, ozone can be removed from the air inside the housing by the first exhaust filter, and particulates can be removed by the second exhaust filter. Therefore, discharge of air containing ozone and particulates to the outside of the housing can be suppressed.

[0024] Further, the second exhaust filter has a shorter service life than the first exhaust filter.

[0025] Since the second exhaust filter is supported by a filter holder that is detachably attached to the side wall, even if the second exhaust filter has a shorter service life and requires higher replacement frequency than the first exhaust filter, the complication of replacement work can be suppressed. [Effects of the Invention]

[0026] According to the present invention, the arrangement accuracy of the first exhaust filter and the second exhaust filter can be improved. [Brief Description of the Drawings]

[0027] [Figure 1] It is a schematic central cross-sectional view showing an image forming apparatus. [Figure 2] It is a perspective view showing an image forming apparatus. [Figure 3] It is a plan view showing the vicinity of the protruding portion of the right side wall. [Figure 4] It is a side view showing a rib protruding inward of the housing formed on the right side wall, and the first exhaust filter supported by the right side wall. [Figure 5] It is a perspective view showing a rib protruding inward of the housing formed on the right side wall, and the first exhaust filter supported by the right side wall. [Figure 6] It is a perspective view showing the image forming apparatus in a state where the filter holder is attached to the right side wall. [Figure 7] (a) is a right side view showing the holder housing, and (b) is a left side view showing the holder housing. [Figure 8] (a) is a perspective view of the holder housing as viewed from the right, and (b) is a perspective view of the holder housing as viewed from the left. [Figure 9] It is a cross-sectional plan view showing the right side wall to which the filter holder is attached. [Figure 10] It is a side view showing the holder housing attached to the right side wall. [Figure 11] It is a perspective view showing the filter holder. [Figure 12]This is a perspective view showing the second exhaust filter exposed to the outside through the second opening in the holder housing of the filter holder with the cover removed. [Figure 13] This is a perspective view showing a modified version of the right wall. [Figure 14] This is a perspective view showing an image forming apparatus according to the second embodiment. [Figure 15] This is a plan view showing the vicinity of the protruding portion on the right wall of the image forming apparatus according to the second embodiment. [Figure 16] This is a side view showing the louvers and louver frame formed on the right wall of the image forming apparatus according to the second embodiment. [Figure 17] This is a side view showing a rib projecting inward from the housing formed on the right side wall of an image forming apparatus according to the second embodiment, and a first exhaust filter supported on the right side wall. [Figure 18] This is a side view showing the image forming apparatus according to the second embodiment with a filter holder attached. [Figure 19] This is a plan cross-sectional view showing the right side wall to which a filter holder is attached in an image forming apparatus according to the second embodiment. [Figure 20] This is a rear cross-sectional view showing the right side wall to which a filter holder is attached in an image forming apparatus according to the second embodiment. [Figure 21] This is a side view showing a holder housing attached to the right wall of an image forming apparatus according to the second embodiment. [Figure 22] This is a partial perspective view showing a holder housing attached to the right side wall of an image forming apparatus according to the second embodiment. [Figure 23] This is a perspective view showing a second exhaust filter exposed to the outside through a second opening in the holder housing of a filter holder with its cover removed, in an image forming apparatus according to a second embodiment. [Figure 24] This is a perspective view showing a modified example of the right side wall in the image forming apparatus according to the second embodiment. [Modes for carrying out the invention]

[0028] Next, embodiments for carrying out the present invention will be described with reference to the attached drawings.

[0029] [Image forming apparatus] The image forming apparatus 1 shown in Figure 1 is an embodiment of the image forming apparatus according to the present invention, and is a laser printer that forms an image on a sheet S using an electrophotographic method.

[0030] In the following explanation, the right side of Figure 1 is defined as the front side of the image forming apparatus 1, the left side of Figure 1 is defined as the rear side of the image forming apparatus 1, the front of the page in Figure 1 is defined as the left side of the image forming apparatus 1, and the back of the page in Figure 1 is defined as the right side of the image forming apparatus 1. Furthermore, the top and bottom sides of Figure 1 are defined as the top and bottom sides of the image forming apparatus 1, respectively.

[0031] The image forming apparatus 1 comprises a housing 2, a paper feeding unit 3, an image forming unit 5, a fuser 6, and a paper discharge unit 29.

[0032] The housing 2 houses the paper feeding unit 3, the image forming unit 5, the fuser unit 6, and the paper discharge unit 29. An opening 20 is located on the front of the housing 2, and the housing 2 has a front cover 21 that can open and close the opening 20. The front cover 21 is configured to rotate around a pivot axis 21a at its lower end, and by rotating around the pivot axis 21a, it can move between a closed position that closes the opening 20 and an open position that opens the opening 20.

[0033] The paper feeding unit 3 comprises a paper feeding tray 10 that supports the sheet S, a sheet transport unit 30, a transport roller pair 34, and a registration roller 35a. The paper feeding unit 3 is located at the bottom of the housing 2 and transports the sheet S supported by the paper feeding tray 10 to the image forming unit 5. The image forming apparatus 1 has a transport path P for the sheet S from the paper feeding unit 3 through the image forming unit 5 to the paper discharge unit 29.

[0034] The paper feed tray 10 has a pressure plate 12 and a pressing plate 13. The pressure plate 12 is a plate-shaped member that supports the sheet S from below. The pressure plate 12 is rotatable about a pivot point 12a at its rear end, and by rotating about the pivot point 12a, it can move up and down between a lowered position and an elevated position. The pressing plate 13 is located below the pressure plate 12 and can move the pressure plate 12 up and down between a lowered position and an elevated position.

[0035] The sheet transport unit 30 is a transport mechanism that separates and removes sheets S supported by the paper feed tray 10 one by one and transports them toward the image forming unit 5, and is equipped with a paper feed roller 31, a separation roller 32, and a separation pad 33.

[0036] The paper feed roller 31 is a roller for feeding the sheet S, supported by the paper feed tray 10, toward the separation roller 32. The separation roller 32 is located downstream of the paper feed roller 31 in the sheet transport direction, and the separation pad 33 is positioned opposite the separation roller 32 and is biased toward the separation roller 32.

[0037] The sheets S, fed towards the separation roller 32 by the paper feed roller 31, are separated one by one between the separation roller 32 and the separation pad 33. The separated sheets S are then fed into the transport path P.

[0038] The sheet S, which has been sent onto the transport path P, is transported toward the image forming unit 5 by the transport roller pair 34, the register roller 35a, and the pinch roller 35b positioned opposite the register roller 35a. The register roller 35a restricts the movement of the leading edge of the sheet S being transported from the paper feed tray 10 toward the image forming unit 5, stopping it temporarily, correcting the tilt of the sheet S, and then transporting the sheet S toward the image forming unit 5 at a predetermined timing. The register roller 35a is a roller for correcting the tilt of the sheet S being transported toward the image forming unit 5.

[0039] The image forming unit 5 is located downstream of the paper feeding unit 3 in the sheet transport direction and forms an image on the sheet S transported from the paper feeding unit 3. In other words, the image forming unit 5 is capable of printing an image on the sheet S. The image forming unit 5 includes a process cartridge 50 that transfers a toner image to the surface of the sheet S transported from the paper feeding unit 3, a transfer roller 55 positioned opposite the photosensitive drum 54 of the process cartridge 50, and an exposure unit 56 that exposes the surface of the photosensitive drum 54.

[0040] The process cartridge 50 is located above the paper feed section 3 in the housing 2 and includes a toner storage chamber 51, a supply roller 52, a developing roller 53, a photosensitive drum 54, a charger 57, and the like. The process cartridge 50 supports the pinch roller 35b.

[0041] The process cartridge 50 comprises a drum cartridge having a photosensitive drum 54 and a developing cartridge mounted on the drum cartridge and having a developing roller 53, and is detachably mounted on the housing 2. In this case, the process cartridge 50 is mounted on the housing 2 by inserting the drum cartridge and the developing cartridge mounted on the drum cartridge into the housing 2 as a single unit, and is detached from the housing 2 by removing the drum cartridge and the developing cartridge mounted on the drum cartridge from the housing 2 as a single unit.

[0042] The process cartridge 50 may consist of at least one of a photosensitive drum, a developing roller, and a toner container. The process cartridge 50 can be attached to and detached from the housing 2 when the front cover 21 is in the open position.

[0043] The photosensitive drum 54 is positioned with its axis aligned in the left-right direction when the process cartridge 50 is mounted in the housing 2. The photosensitive drum 54 has a metal drum shaft 54a that extends along the axial direction. The photosensitive drum 54 rotates about the drum shaft 54a.

[0044] In this embodiment, the process cartridge 50 comprises a drum cartridge having a photosensitive drum 54 and a developing cartridge mounted on the drum cartridge and having a developing roller 53. However, it can also be configured to include a cartridge having the photosensitive drum 54 and the developing roller 53, and a toner box mounted on the cartridge for containing toner.

[0045] Furthermore, in the image forming apparatus 1, a drum cartridge having a photosensitive drum 54 and a developing cartridge having a developing roller 53 can be configured to be mounted separately in the housing 2. That is, the process cartridge 50 can include at least one of a photosensitive drum, a developing roller, and a toner container, and can be configured to be detachably mounted in the main body of the apparatus.

[0046] The exposure unit 56 is equipped with a laser diode, a polygon mirror, a lens, and a reflector, and exposes the surface of the photosensitive drum 54 by irradiating the photosensitive drum 54 with laser light based on image data input to the image forming apparatus 1.

[0047] The toner storage chamber 51 contains toner, which is used as a developer. The toner stored in the toner storage chamber 51 is agitated by an agitator (not shown) and sent to the supply roller 52. The supply roller 52 then supplies the toner sent from the toner storage chamber 51 to the developer roller 53.

[0048] The developing roller 53 is positioned in close contact with the supply roller 52 and carries positively charged toner supplied from the supply roller 52 by a sliding contact member (not shown). A developing bias is also applied to the developing roller 53 by a bias application means (not shown).

[0049] The photosensitive drum 54 is positioned adjacent to the developing roller 53. The surface of the photosensitive drum 54 is uniformly charged by the charger 57 and then exposed by the exposure unit 56. The exposed portion of the photosensitive drum 54 has a lower potential than other portions, and an electrostatic latent image based on the image data is formed on the photosensitive drum 54. Then, positively charged toner is supplied from the developing roller 53 to the surface of the photosensitive drum 54 where the electrostatic latent image has been formed, causing the electrostatic latent image to become visible as a toner image.

[0050] The transfer roller 55 is positioned opposite the photosensitive drum 54, and a transfer bias is applied by a bias application means (not shown). With the transfer bias applied to the surface of the transfer roller 55, the sheet S is transported while being sandwiched between the photosensitive drum 54, on which the toner image has been formed, and the transfer roller 55, thereby transferring the toner image formed on the surface of the photosensitive drum 54 to the surface of the sheet S. In this way, the photosensitive drum 54 forms a toner image on the sheet S. The photosensitive drum 54 is an example of a drum that forms a toner image on a sheet. The sheet S on which the toner image has been transferred is transported to the fuser 6.

[0051] The fuser 6 comprises a heating unit 61 and a pressure roller 62, and fixes the toner image formed on the sheet S. The heating unit 61 is heated by power supplied from a power source (not shown). The pressure roller 62 is positioned opposite the heating unit 61. One of the heating unit 61 and the pressure roller 62 is biased toward the other by a biasing mechanism (not shown), and the heating unit 61 and the pressure roller 62 are in close contact. The image forming apparatus 1 is equipped with a motor 4, and the pressure roller 62 of the fuser 6 is driven and rotated by the driving force from the motor 4.

[0052] When the sheet S on which the toner image has been transferred is transported to the fuser unit 6, the sheet S is heated while being held between the heating unit 61 and the pressure roller 62, thereby fixing the toner image to the sheet S. In this way, the fuser unit 6 fixes the toner image formed on the sheet S.

[0053] The paper discharge unit 29 is located downstream of the image forming unit 5 in the sheet transport direction, and discharges the sheet S, on which an image has been formed in the image forming unit 5, to the outside of the image forming apparatus 1. The paper discharge unit 29 comprises a pair of paper discharge rollers 291 and a paper discharge tray 292. The pair of paper discharge rollers 291 is configured to discharge the sheet S, which has been transported from the fuser 6 along the transport path P, toward the outside of the housing 2. The paper discharge tray 292 is provided on the top cover 22 of the housing 2. The paper discharge tray 292 supports the sheet S that has been discharged to the outside of the housing 2 by the pair of paper discharge rollers 291.

[0054] [fan] As shown in Figures 1 and 2, the image forming apparatus 1 is equipped with a fan 71 that exhausts the air inside the housing 2 to the outside of the housing 2. The fan 71 is located to the right of the image forming unit 5 inside the housing 2.

[0055] The right frame 26 is housed at the rightmost end of the enclosure 2, and the enclosure 2 has a right side wall 23 that covers the right side of the right frame 26. The right side wall 23 is an example of a side wall provided by the enclosure. The right side wall 23 is located downstream of the fan 71 in the exhaust direction of the fan 71.

[0056] The right side wall 23 has a projection 23A that protrudes to the right more than the rest of the wall. The projection 23A is located at the rear upper part of the right side wall 23. The right side wall 23 has an exhaust port 23a that penetrates the right side wall 23 in the left-right direction. The exhaust port 23a is formed in the projection 23A. The exhaust port 23a is formed in a circular shape. The right side wall 23 is an example of a side wall having an exhaust port.

[0057] The fan 71 is supported by the right frame 26 and is positioned so as to overlap with the exhaust port 23a when viewed from the left or right direction. When the fan 71 is driven, an airflow is generated from left to right, and the airflow created by the fan 71 exhausts the air inside the housing 2 to the outside of the housing 2 through the exhaust port 23a. As the fan 71, for example, an axial flow fan can be used, which has a rotating shaft extending along the left-right direction and blades fixed to the rotating shaft, and which sends air along the axial direction of the rotating shaft.

[0058] [Luva] As shown in Figures 2 and 3, the right side wall 23 of the housing 2 has a louver 241 positioned at the exhaust port 23a. The louver 241 is located to the right of the fan 71. The louver 241 restricts the direction of exhaust of the air being exhausted through the exhaust port 23a.

[0059] The louvers 241 are formed in the shape of long plates extending in the front-to-back direction and are inclined upward from left to right. Multiple louvers 241 are arranged along the vertical direction. Air exhausted from left to right through the exhaust port 23a has its exhaust direction changed to diagonally upward to the right as it passes through the louvers 241. In other words, the louvers 241 restrict the exhaust direction of the exhausted air to diagonally upward to the right.

[0060] The right side wall 23 has a louver frame 240 that surrounds the outer periphery of the louver 241. The louver frame 240 is formed in a circular shape. The louver frame 240 protrudes to the right from the projection 23A of the right side wall 23. In other words, the louver frame 240 is an outer protruding wall that protrudes outward from the outer surface of the projection 23A on the right side wall 23 toward the outside of the housing 2. The louver frame 240 is also an example of a frame that serves as an outer protruding wall surrounding the outer periphery of the louver.

[0061] [First exhaust filter] As shown in Figures 2 to 4, the image forming apparatus 1 is equipped with a first exhaust filter 72 located between the louver 241 and the fan 71 on the right side wall 23 in the left-right direction. When viewed from the left-right direction, the first exhaust filter 72 is positioned to overlap with the exhaust port 23a formed on the protrusion 23A of the right side wall 23 and the louver 241. The first exhaust filter 72 is supported by the protrusion 23A of the right side wall 23.

[0062] The first exhaust filter 72 can be constructed, for example, as a honeycomb filter in which the filter material is formed in a honeycomb shape. As the filter material constituting the first exhaust filter 72, for example, paper supported with an ozone decomposition catalyst such as manganese dioxide or activated carbon, a metal such as aluminum, or ceramics can be used. In this embodiment, the first exhaust filter 72 is conductive. The first exhaust filter 72 is formed in a sheet shape.

[0063] In this embodiment, the first exhaust filter 72 is an ozone decomposition filter capable of decomposing ozone contained in the air passing through it. Inside the housing 2, ozone is generated by components that generate discharge into the atmosphere, such as the charger 57 provided in the process cartridge 50. The air inside the housing 2 containing ozone is drawn in by the fan 71 and passes through the first exhaust filter 72, thereby removing the ozone.

[0064] [Right side wall] As shown in Figures 4 and 5, the right side wall 23 has a first rib 231, a second rib 232, a third rib 233, and a fourth rib 234 that protrude inward from the housing 2.

[0065] The first rib 231 is located in front of and below the louver 241 on the projection 23A of the right side wall 23, and protrudes from the inner surface of the projection 23A toward the left, which is inward of the housing 2. The first rib 231 extends along the projection 23A and slopes downward as it is directed toward the rear.

[0066] The second rib 232 is located above and behind the louver 241 on the projection 23A of the right side wall 23, and protrudes from the inner surface of the projection 23A toward the left, which is inward of the housing 2. The second rib 232 extends along the projection 23A and slopes downward as it is directed toward the rear.

[0067] The third rib 233 is located below and rear of the louver 241 on the projection 23A of the right side wall 23, and protrudes from the inner surface of the projection 23A toward the left, which is inward of the housing 2. The third rib 233 extends along the projection 23A. The third rib 233 extends approximately in the front-rear direction.

[0068] The fourth rib 234 is located in front of and above the louver 241 on the projection 23A of the right side wall 23, and protrudes from the inner surface of the projection 23A toward the left, which is inward of the housing 2. The fourth rib 234 extends along the projection 23A and slopes downward as it extends forward.

[0069] The first rib 231 is located in front of and below the first exhaust filter 72, which is supported by a projection 23A of the right side wall 23. The first rib 231 is in contact with the front lower part of the first exhaust filter 72.

[0070] The second rib 232 is located rear and above the first exhaust filter 72, which is supported by a projection 23A of the right side wall 23. A pressing body 73 is positioned between the second rib 232 and the rear upper part of the first exhaust filter 72. The pressing body 73 is in contact with the second rib 232 and the rear upper part of the first exhaust filter 172.

[0071] The pressing body 73 is made of an elastic material such as sponge and presses the first exhaust filter 72 toward the first rib 231. The first exhaust filter 72 is pressed against the first rib 231 by the pressure from the pressing body 73.

[0072] The third rib 233 is located rear and below the first exhaust filter 72, which is supported by a projection 23A of the right side wall 23. The third rib 233 is in contact with the rear lower part of the exhaust filter 72.

[0073] The fourth rib 234 is located in front of and above the exhaust filter 72, which is supported by the protrusion 23A of the right side wall 23. The fourth rib 234 faces the front upper part of the exhaust filter 72 with a gap between them.

[0074] The first rib 231, second rib 232, third rib 233, and fourth rib 234 are located in front-lower, rear-upper, rear-lower, and front-upper positions, respectively, of the first exhaust filter 72. This allows the first exhaust filter 72 to be guided to the mounting position relative to the protrusion 23A of the right side wall 23 by the first rib 231, second rib 232, third rib 233, and fourth rib 234 when the first exhaust filter 72 is attached to the right side wall 23.

[0075] Furthermore, the first exhaust filter 72, supported by the protrusion 23A of the right side wall 23, is pressed against the first rib 231 by the pressing body 73 and also comes into contact with the third rib 233, thereby being positioned in the direction along the right side wall 23.

[0076] The first rib 231 and the third rib 233 are examples of first positioning parts that position the first exhaust filter in a direction along the side wall. The first rib 231 and the third rib 233 are also examples of inner protruding walls that act as first positioning parts, projecting inward from the inner surface of the side wall towards the housing.

[0077] Furthermore, the right side wall 23 has a fifth rib 235 and a sixth rib 236 that project inward from the housing 2. The fifth rib 235 and the sixth rib 236 are formed along the periphery of the exhaust port 23a in the projection 23A of the right side wall 23. The fifth rib 235 and the sixth rib 236 project to the left from the projection 23A of the right side wall 23. The fifth rib 235 and the sixth rib 236 project inward from the housing 2 beyond the louvers 241. The amount of leftward projection of the fifth rib 235 is greater than the amount of leftward projection of the sixth rib 236.

[0078] The fifth rib 235 has a first part 235a, a second part 235b, a third part 235c, and a fourth part 235d. The first part 235a is located at the upper end of the exhaust port 23a, the second part 235b is located at the lower end of the exhaust port 23a, the third part 235c is located at the front end of the exhaust port 23a, and the fourth part 235d is located at the rear end of the exhaust port 23a.

[0079] The sixth rib 236 has a first part 236a, a second part 236b, a third part 236c, and a fourth part 236d.

[0080] The first part 236a of the sixth rib 236 is located between the first part 235a and the third part 235c of the fifth rib 235. The second part 236b of the sixth rib 236 is located between the second part 235b and the third part 235c of the fifth rib 235. The third part 236c of the sixth rib 236 is located between the second part 235b and the fourth part 235d of the fifth rib 235. The fourth part 236d of the sixth rib 236 is located between the first part 235a and the fourth part 235d of the fifth rib 235.

[0081] The first part 236a of the sixth rib 236 faces the fourth rib 234. The second part 236b of the sixth rib 236 faces the first rib 231. The third part 236c of the sixth rib 236 faces the third rib 233. The fourth part 236d of the sixth rib 236 faces the second rib 232.

[0082] The sixth rib 236 is located to the right of the first exhaust filter 72, which is supported by a projection 23A of the right side wall 23. The sixth rib 236 is in contact with the right side surface of the first exhaust filter 72.

[0083] The first part 236a of the sixth rib 236 is in contact with the front upper part of the first exhaust filter 72. The second part 236b of the sixth rib 236 is in contact with the front lower part of the first exhaust filter 72. The third part 236c of the sixth rib 236 is in contact with the rear lower part of the first exhaust filter 72. The fourth part 236d of the sixth rib 236 is in contact with the rear upper part of the first exhaust filter 72.

[0084] The first exhaust filter 72, supported by the right side wall 23, is positioned in the left-right direction, which is perpendicular to the direction along the right side wall 23, by having its right side surface in contact with the sixth rib 236.

[0085] Furthermore, the first part 235a, second part 235b, third part 235c, and fourth part 235d of the fifth rib 235 are each capable of contacting the first exhaust filter 72, and by contacting the first exhaust filter 72, they can be positioned along the right side wall 23 of the first exhaust filter 72.

[0086] [Filter holder and second exhaust filter] As shown in Figure 6, a filter holder 80 can be detachably attached to the right side wall 23 of the image forming apparatus 1. In other words, the image forming apparatus 1 can be configured to include a filter holder 80 that is detachably attached to the right side wall 23. The filter holder 80 supports the second exhaust filter 75. The second exhaust filter 75 is housed inside the filter holder 80.

[0087] As shown in Figure 9, with the filter holder 80 attached to the right side wall 23, the second exhaust filter 75 is positioned so as to overlap with the exhaust port 23a and louvers 241 formed on the protrusion 23A of the right side wall 23 when viewed from the left and right directions. The second exhaust filter 75 is sized to cover the entire exhaust port 23a and louvers 241.

[0088] The second exhaust filter 75 can be constructed, for example, as a honeycomb filter in which the filter material is formed in a honeycomb shape. As the filter material for the second exhaust filter 75, for example, paper supported with an ozone decomposition catalyst such as manganese dioxide or activated carbon, a metal such as aluminum, or ceramics can be used. The second exhaust filter 75 has a roughly rectangular parallelepiped shape.

[0089] In this embodiment, the second exhaust filter 75 is a particulate filter capable of removing particulate matter contained in the air passing through it. Particulate matter such as toner contained in the process cartridge 50 may be suspended inside the housing 2. The air inside the housing 2 is drawn in by the fan 71, passes through the first exhaust filter 72 to remove ozone, and then passes through the second exhaust filter 75 to remove particulate matter before being exhausted. Therefore, it is possible to suppress the exhaust of air containing ozone and particulate matter to the outside of the housing 2.

[0090] As shown in Figures 6 to 10, the filter holder 80 comprises a holder housing 80A and a cover 80B. The second exhaust filter 75 is housed inside the holder housing 80A, and the second exhaust filter 75 is supported by the holder housing 80A.

[0091] The holder housing 80A is formed in the shape of a box with a roughly rectangular parallelepiped. The holder housing 80A is detachably attached to the right side wall 23. The holder housing 80A has a mounting wall 82 and a side wall 83.

[0092] The mounting wall 82 is located at the left end of the holder housing 80A when the holder housing 80A is mounted on the right side wall 23, and faces the right side wall 23. When the holder housing 80A is mounted on the right side wall 23, the right side wall 23 and the mounting wall 82 are arranged parallel to each other. The mounting wall 82 has a first opening 85.

[0093] The first opening 85 is formed in a rectangular shape, and the inner circumferential surface of the first opening 85 in the mounting wall 82 has a first inner circumferential surface 85a, a second inner circumferential surface 85b, a third inner circumferential surface 85c, and a fourth inner circumferential surface 85d. The first inner circumferential surface 85a is located on the upper periphery of the first opening 85, the second inner circumferential surface 85b is located on the lower periphery of the first opening 85, the third inner circumferential surface 85c is located on the front periphery of the first opening 85, and the fourth inner circumferential surface 85d is located on the rear periphery of the first opening 85.

[0094] The first inner surface 85a and the second inner surface 85b extend in the front-rear direction. The third inner surface 85c and the fourth inner surface 85d extend in the up-down direction. The front-rear direction is an example of a first direction, which is the direction along the side wall, and the up-down direction is an example of a second direction, which is perpendicular to the first direction. The first inner surface 85a and the second inner surface 85b are examples of first surfaces that extend along the first direction, and the third inner surface 85c and the fourth inner surface 85d are examples of second surfaces that extend along the second direction.

[0095] The vertical distance between the first inner surface 85a and the second inner surface 85b, and the front-to-back distance between the third inner surface 85c and the fourth inner surface 85d, are formed to match the outer diameter of the circularly formed louver frame 240.

[0096] Specifically, the vertical distance between the first inner surface 85a and the second inner surface 85b, and the front-to-back distance between the third inner surface 85c and the fourth inner surface 85d, are formed to be slightly larger than the outer diameter of the circularly formed louver frame 240. This makes it possible to fit the first opening 85 of the mounting wall 82 into the louver frame 240.

[0097] When the louver frame 240 is fitted into the first opening 85, the first inner surface 85a, the second inner surface 85b, the third inner surface 85c, and the fourth inner surface 85d can come into contact with the louver frame 240.

[0098] The holder housing 80A can be attached to the right side wall 23, for example, using double-sided tape. The mounting wall 82 has an adhesive portion 82a, and the holder housing 80A can be attached to the right side wall 23 by adhering the double-sided tape attached to the adhesive portion 82a to the right side wall 23. The adhesive portion 82a is positioned adjacent to the third inner circumferential surface 85c and the fourth inner circumferential surface 85d of the first opening 85, and the holder housing 80A can be adhered to the protrusion 23A located around the exhaust port 23a.

[0099] In this embodiment, the holder housing 80A is attached to the right side wall 23 using double-sided tape, but it can also be attached to the right side wall 23 by other methods, such as using hook-and-loop fasteners or adhesive.

[0100] The side wall 83 extends to the right from the periphery of the mounting wall 82. The side wall 83 has a first side wall 83A, a second side wall 83B, a third side wall 83C, and a fourth side wall 83D. When the holder housing 80A is attached to the right side wall 23, the first side wall 83A is located at the upper end of the holder housing 80A, the second side wall 83B is located at the lower end of the holder housing 80A, the third side wall 83C is located at the front end of the holder housing 80A, and the fourth side wall 83D is located at the rear end of the holder housing 80A.

[0101] An engaging portion 89A is formed on the first side wall 83A of the holder housing 80A, and an engaging portion 89B is formed on the second side wall 83B. The cover 80B is attached to the holder housing 80A by engaging the engaging portions 89A and 89B with the cover 80B.

[0102] In this embodiment, the engaging portion 89A is formed at one location on the first side wall 83A, and the engaging portions 89B are formed at two locations on the second side wall 83B. However, the number of engaging portions 89A and 89B formed and the positions of the side wall 83 are not limited to this.

[0103] When the holder housing 80A is attached to the right side wall 23, the right end is completely open, forming a second opening 86. The opening area of ​​the first opening 85 is smaller than the opening area of ​​the second opening 86.

[0104] In the holder housing 80A, the second exhaust filter 75 is housed in the space enclosed by the mounting wall 82 and the first side wall 83A, second side wall 83B, third side wall 83C, and fourth side wall 83D of the side wall 83.

[0105] The holder housing 80A has a positioning rib 88A that protrudes from the inner surface of the first side wall 83A toward the inside of the holder housing 80A, a positioning rib 88B that protrudes from the inner surface of the second side wall 83B toward the inside of the holder housing 80A, a positioning rib 88C that protrudes from the inner surface of the third side wall 83C toward the inside of the holder housing 80A, and a positioning rib 88D that protrudes from the inner surface of the fourth side wall 83D toward the inside of the holder housing 80A.

[0106] Positioning rib 88A protrudes downward from the first side wall 83A, positioning rib 88B protrudes upward from the second side wall 83B, positioning rib 88C protrudes rearward from the third side wall 83C, and positioning rib 88D protrudes forward from the fourth side wall 83D.

[0107] The second exhaust filter 75, housed within the holder housing 80A, is positioned in the front-to-back and up-to-down directions along the mounting wall 82 by contacting the positioning ribs 88A, 88B, 88C, and 88D.

[0108] In the direction along the mounting wall 82, the lower end of positioning rib 88A is located above the first inner surface 85a, the upper end of positioning rib 88B is located below the second inner surface 85b, the rear end of positioning rib 88C is located in front of the third inner surface 85c, and the front end of positioning rib 88D is located behind the fourth inner surface 85d. In other words, positioning ribs 88A, 88B, 88C, and 88D are located outside the first opening 85 in the direction along the mounting wall 82.

[0109] Therefore, the second exhaust filter 75, positioned by the positioning ribs 88A, 88B, 88C, and 88D, can completely cover the first opening 85, thereby preventing air that does not pass through the second exhaust filter 75 from being exhausted through the first opening 85.

[0110] The holder housing 80A has a positioning wall 87 that protrudes to the right from the mounting wall 82. The second exhaust filter 75 housed within the holder housing 80A is positioned in the left-right direction, which is perpendicular to the direction along the mounting wall 82, by contacting the positioning wall 87.

[0111] The projection length of the positioning wall 87 from the mounting wall 82 is D. The projection length D is set so that the second exhaust filter 75, which is positioned in the left-right direction by the positioning wall 87, does not come into contact with the louver frame 240 that protrudes to the right from the projection 23A of the right side wall 23.

[0112] As shown in Figure 10, when attaching the holder housing 80A that supports the second exhaust filter 75 to the right side wall 23, the first opening 85 of the mounting wall 82 of the holder housing 80A is fitted into the louver frame 240 of the right side wall 23. Furthermore, with one of the first inner surface 85a and the second inner surface 85b, and one of the third inner surface 85c and the fourth inner surface 85d of the first opening 85 into which the louver frame 240 is fitted, in contact with the louver frame 240, the holder housing 80A is attached to the right side wall 23.

[0113] In this embodiment, the holder housing 80A is attached to the right side wall 23 with the first inner surface 85a and the fourth inner surface 85d of the first opening 85 in contact with the louver frame 240. However, it is also possible to attach the holder housing 80A to the right side wall 23 with the first inner surface 85a and the third inner surface 85c in contact with the louver frame 240, the second inner surface 85b and the third inner surface 85c in contact with the louver frame 240, or the second inner surface 85b and the fourth inner surface 85d in contact with the louver frame 240.

[0114] In this way, by bringing the inner surface of the first opening 85 into contact with the louver frame 240, the holder housing 80A can be positioned relative to the right side wall 23 in a direction along the right side wall 23. This improves the positional accuracy of the filter holder 80 attached to the right side wall 23 relative to the louver 241 in a direction along the right side wall 23.

[0115] In particular, by bringing one of the first inner surface 85a and the second inner surface 85b, and one of the third inner surface 85c and the fourth inner surface 85d, into contact with the louver frame 240, the holder housing 80A can be positioned vertically and horizontally with respect to the right side wall 23. This makes it easy to improve the positional accuracy of the filter holder 80 attached to the right side wall 23 with respect to the louver 241 in the direction along the right side wall 23.

[0116] Thus, the right side wall 23 has a louver frame 240 as an outer protruding wall surrounding the outer circumference of the louver 241, which makes it possible to improve the accuracy of the positional position of the filter holder 80 supporting the second exhaust filter 75 relative to the louver 241. The louver frame 240 is an example of a second positioning part that positions the filter holder in a direction along the side wall.

[0117] Furthermore, the louver frame 240, which serves as an outer protruding wall for positioning the filter holder 80 that supports the second exhaust filter 75, and the first rib 231 and third rib 233, which serve as inner protruding walls for positioning the first exhaust filter 72, are both formed on the right side wall 23.

[0118] Therefore, it is possible to improve the precision of the positioning of the first exhaust filter 72 and the second exhaust filter 75. As a result, the air inside the housing 2 will pass through both the first exhaust filter 72 and the second exhaust filter 75 before being exhausted, allowing the functions of the first exhaust filter 72 and the second exhaust filter 75 to be fully performed.

[0119] As shown in Figure 11, the cover 80B of the filter holder 80 has ventilation openings 81 on the surface facing the mounting wall 82 of the holder housing 80A. The ventilation openings 81 are slit-shaped openings that extend along the front-rear direction. Multiple ventilation openings 81 are formed along the vertical direction.

[0120] The cover 80B, attached to the holder housing 80A, closes the second opening 86 of the holder housing 80A. The exhaust from inside the housing 2 passes through the second exhaust filter 75 housed in the filter holder 80, and is then exhausted to the outside through the ventilation opening 81 of the cover 80B.

[0121] As shown in Figure 12, when the cover 80B of the filter holder 80 attached to the right side wall 23 is removed from the holder housing 80A, the second opening 86 of the holder housing 80A is open, and the second exhaust filter 75 housed in the holder housing 80A is exposed to the outside through the second opening 86.

[0122] In this way, by removing the cover 80B from the holder housing 80A, the second exhaust filter 75 is exposed to the outside, making it easy to replace the second exhaust filter 75.

[0123] Here, the first exhaust filter 72 removes ozone contained in the passing air by decomposing it, so it is less prone to clogging and tends to have a longer lifespan. On the other hand, the second exhaust filter 75 removes particulate matter contained in the passing air by capturing it, so it is more prone to clogging, and the lifespan of the second exhaust filter 75 tends to be shorter than that of the first exhaust filter 72.

[0124] The second exhaust filter 75 has a shorter lifespan than the first exhaust filter 72 and therefore requires more frequent replacement. However, since the second exhaust filter 75 is supported by a filter holder 80 that is detachably attached to the right side wall 23, the replacement process can be made less complicated despite the higher replacement frequency. In particular, the second exhaust filter 75 can be easily replaced by removing the cover 80B of the filter holder 80, thus simplifying the replacement process.

[0125] [Modified view of the right wall] The right side wall 23 can also be formed as the right side wall 23-1 shown in Figure 13. The right side wall 23-1 differs from the right side wall 23 which has a protrusion 23A in that it does not have a protrusion 23A. Also, the right side wall 23-1 differs from the right side wall 23 which supports the first exhaust filter 72 in that it does not support the first exhaust filter 72. The other configurations of the right side wall 23-1 are the same as those of the right side wall 23.

[0126] The right side wall 23-1 is formed to be generally flat as it does not have a protrusion 23A that projects to the right. A circular exhaust port 23a-1 is formed in the right side wall 23-1. The right side wall 23-1 has a louver 241-1 positioned in the exhaust port 23a-1 and a circular louver frame 240-1 surrounding the outer circumference of the louver 241-1.

[0127] The exhaust port 23a-1, louver frame 240-1, and louver 241-1 are formed in the same manner as the exhaust port 23a, louver frame 240, and louver 241 of the right side wall 23, respectively. The right side wall 23-1 is an example of a side wall having an exhaust port.

[0128] The filter holder 80 can be attached to the right side wall 23-1, similar to the case of the right side wall 23. The amount of protrusion of the louver frame 240-1 from the right side wall 23-1 is the same as the amount of protrusion of the louver frame 240 from the protrusion portion 23A on the right side wall 23, so even when the filter holder 80 is attached to the right side wall 23-1, the second exhaust filter 75 and the louver frame 240-1 will not come into contact.

[0129] Furthermore, the distance between the second exhaust filter 75 and the louver 241-1 of the right wall 23-1 when the filter holder 80 is attached to the right wall 23-1 is the same as the distance between the second exhaust filter 75 and the louver 241 of the right wall 23 when the filter holder 80 is attached to the right wall 23.

[0130] Therefore, it is possible to make the particulate matter collection efficiency of the second exhaust filter 75 equivalent to that of the filter holder 80 when it is attached to the right side wall 23, and the particulate matter collection efficiency of the second exhaust filter 75 when it is attached to the right side wall 23-1.

[0131] [Second Embodiment of Image Forming Apparatus] The image forming apparatus 1, which includes a housing 2 having an exhaust port 23a, a fan 71 for exhausting air from inside the housing 2, and a filter holder 80 detachably attached to the right side wall 23 of the housing 2, can also be configured as the image forming apparatus 1A shown in Figure 14.

[0132] As shown in Figures 14 and 15, the image forming apparatus 1A differs from the image forming apparatus 1 in that it has a housing 2A, a right frame 126, a fan 171, and an exhaust filter 172 instead of the housing 2, right frame 26, fan 71, and exhaust filter 72. The other components of the image forming apparatus 1A are the same as those of the image forming apparatus 1, so their description is omitted.

[0133] Enclosure 2A differs from enclosure 2 in that it has a right-side wall 123 instead of the right-side wall 23. The other configurations of enclosure 2A are the same as those of enclosure 2, so their explanation is omitted.

[0134] A fan 171 is housed inside the housing 2A to exhaust the air inside the housing 2A to the outside. The fan 171 is located to the right of the image forming unit 5 inside the housing 2A.

[0135] The right frame 126 is housed at the rightmost end of the enclosure 2A, and the enclosure 2A has a right side wall 123 that covers the right side of the right frame 126. The right side wall 123 is an example of a side wall provided by the enclosure. The right side wall 123 is located downstream of the fan 171 in the exhaust direction of the fan 171.

[0136] Unlike the right side wall 23, the right side wall 123 does not have a protruding portion 23A. The right side wall 123 has an exhaust port 123a that penetrates the right side wall 123 in the left-right direction. The exhaust port 123a is located at the lower rear of the right side wall 123. The exhaust port 123a is formed in a square shape. The right side wall 123 is an example of a side wall having an exhaust port.

[0137] (fan) The fan 171 is supported by the right frame 126 and is positioned so as to overlap with the exhaust port 123a when viewed from the left or right direction. When the fan 171 is driven, an airflow is generated from left to right, and the airflow created by the fan 171 exhausts the air inside the housing 2A to the outside of the housing 2A through the exhaust port 123a. As the fan 171, for example, an axial flow fan can be used, which has a rotating shaft extending along the left-right direction and blades fixed to the rotating shaft, and which sends air along the axial direction of the rotating shaft.

[0138] (Luba) As shown in Figures 14 to 16, the right side wall 123 of the housing 2A has a louver 1241 positioned at the exhaust port 123a. The louver 1241 is located to the right of the fan 171. The louver 1241 restricts the direction of exhaust of the air being exhausted through the exhaust port 123a.

[0139] The louvers 1241 are formed in the shape of long plates extending in the front-to-back direction and are inclined upward from left to right. Multiple louvers 1241 are arranged along the vertical direction. Air exhausted from left to right through the exhaust port 123a has its exhaust direction changed to diagonally upward to the right as it passes through the louvers 1241. In other words, the louvers 1241 restrict the exhaust direction of the exhausted air to diagonally upward to the right.

[0140] The right side wall 123 has a louver frame 1240 that surrounds the outer periphery of the louver 1241. The louver frame 1240 is formed in a rectangular shape. The louver frame 1240 protrudes to the right from the right side wall 123. In other words, the louver frame 1240 is an external protruding wall that protrudes outward from the outer surface of the right side wall 123 toward the outside of the housing 2A. The louver frame 1240 is also an example of a frame that serves as an external protruding wall surrounding the outer periphery of a louver.

[0141] The louver frame 1240 includes an upper frame 1240a located above the louver 1241, a lower frame 1240b located below the louver 1241, a front frame 1240c located in front of the louver 1241, and a rear frame 1240d located behind the louver 1241. The upper frame 1240a and the rear frame 1240d extend along the front-to-back direction, while the front frame 1240c and the rear frame 1240d extend along the up-to-down direction.

[0142] The front-to-back direction is an example of a third direction, which is the direction along the side wall, and the up-and-down direction is an example of a fourth direction, which is perpendicular to the third direction. The upper frame 1240a and lower frame 1240c are examples of a first wall extending along the third direction, and the front frame 1240c and rear frame 1240d are examples of a second wall extending along the fourth direction.

[0143] (First exhaust filter) As shown in Figures 14, 15, and 17, the image forming apparatus 1A includes a first exhaust filter 172 located between the louver 1241 and the fan 171 on the right side wall 123 in the left-right direction. The first exhaust filter 172 is positioned so as to overlap with the exhaust port 123a and the louver 1241 formed on the right side wall 123 when viewed from the left-right direction. The first exhaust filter 172 is supported by the right side wall 123.

[0144] The first exhaust filter 172 can be constructed, for example, as a honeycomb filter in which the filter material is formed in a honeycomb shape. As the filter material constituting the first exhaust filter 172, for example, paper supported with an ozone decomposition catalyst such as manganese dioxide or activated carbon, a metal such as aluminum, or ceramics can be used. In this embodiment, the first exhaust filter 172 is conductive. The first exhaust filter 172 is formed in a sheet shape.

[0145] In this embodiment, the first exhaust filter 172 is an ozone decomposition filter capable of decomposing ozone contained in the air passing through it. Inside the housing 2A, ozone is generated by components that generate discharge into the atmosphere, such as the charger 57 provided in the process cartridge 50. The air inside the housing 2A containing ozone is drawn in by the fan 171 and passes through the first exhaust filter 172, thereby removing the ozone.

[0146] (Right side wall) As shown in Figure 17, the right side wall 123 has a first rib 1231, a second rib 1232, a third rib 1233, and a fourth rib 1234 that protrude inward from the housing 2A.

[0147] The first rib 1231 is located above the louver 1241 on the right side wall 123 and protrudes to the left from the inner surface of the right side wall 123 toward the inside of the housing 2A. The first rib 1231 extends in the front-rear direction along the right side wall 123.

[0148] The second rib 1232 is located below the louver 1241 on the right side wall 123 and protrudes to the left from the inner surface of the right side wall 123 toward the inside of the housing 2A. The second rib 1232 extends in the front-rear direction along the right side wall 123.

[0149] The third rib 1233 is located in front of the louver 1241 on the right side wall 123 and protrudes to the left from the inner surface of the right side wall 123 toward the inside of the housing 2A. The third rib 1233 extends in the vertical direction along the right side wall 123.

[0150] The fourth rib 1234 is located behind the louver 1241 on the right side wall 123 and protrudes from the inner surface of the right side wall 123 toward the left, inward into the housing 2A. The fourth rib 1234 extends in the vertical direction along the right side wall 123.

[0151] The first rib 1231 is located above the first exhaust filter 172, which is supported by the right side wall 123. The first rib 1231 can contact the upper end of the first exhaust filter 172. The second rib 1232 is located below the first exhaust filter 172, which is supported by the right side wall 123. The second rib 1232 can contact the lower end of the first exhaust filter 172.

[0152] The third rib 1233 is located in front of the first exhaust filter 172, which is supported by the right side wall 123. The third rib 1233 can abut against the front end of the first exhaust filter 172. The fourth rib 1234 is located behind the first exhaust filter 172, which is supported by the right side wall 123. The fourth rib 1234 can abut against the rear end of the first exhaust filter 172. In this embodiment, the first exhaust filter 172, supported by the right side wall 123, is in contact with the second rib 1232 and the fourth rib 1234.

[0153] The first rib 1231, the second rib 1232, the third rib 1233, and the fourth rib 1234 are located above, below, in front of, and behind the first exhaust filter 172, respectively. This allows the first exhaust filter 172 to be guided to its mounting position relative to the right side wall 123 by the first rib 1231, the second rib 1232, the third rib 1233, and the fourth rib 1234 when the first exhaust filter 172 is attached to the right side wall 123.

[0154] Furthermore, the first exhaust filter 172, supported by the right side wall 123, is positioned along the right side wall 123 by contacting the second rib 1232 and the fourth rib 1234. The first exhaust filter 172 can also be positioned along the right side wall 123 by contacting the second rib 1232 and the third rib 1233.

[0155] Furthermore, the first exhaust filter 172 can be positioned along the right side wall 123 by contacting the first rib 1231 and the third rib 1233, and it can also be positioned along the right side wall 123 by contacting the first rib 1231 and the fourth rib 1234.

[0156] The first rib 1231, the second rib 1232, the third rib 1233, and the fourth rib 1234 are examples of first positioning parts that position the first exhaust filter in a direction along the side wall. The first rib 1231, the second rib 1232, the third rib 1233, and the fourth rib 1234 are also examples of inner protruding walls that act as first positioning parts, projecting inward from the inner surface of the side wall towards the housing.

[0157] (Filter holder and second exhaust filter) As shown in Figures 18 to 21, the filter holder 80 supporting the second exhaust filter 75 can be detachably attached to the right side wall 123 of the image forming apparatus 1A. In other words, the image forming apparatus 1A can be configured to include a filter holder 80 that is detachably attached to the right side wall 123.

[0158] The filter holder 80 is mounted on the right side wall 123 in a configuration in which the fourth side wall 83D is positioned upward, the third side wall 83C is positioned downward, the first side wall 83A is positioned forward, and the second side wall 83B is positioned backward.

[0159] With the filter holder 80 attached to the right side wall 123, the first inner surface 85a of the first opening 85 is located in front of the louver 1241, the second inner surface 85b is located behind the louver 1241, the third inner surface 85c is located below the louver 1241, and the fourth inner surface 85d is located above the louver 1241.

[0160] The first inner surface 85a and the second inner surface 85b extend along the vertical direction, while the third inner surface 85c and the fourth inner surface 85d extend along the front-to-back direction. The third inner surface 85c and the fourth inner surface 85d are examples of third surfaces extending along the third direction, and the first inner surface 85a and the second inner surface 85b are examples of fourth surfaces extending along the fourth direction.

[0161] The projection length D of the positioning wall 87 from the mounting wall 82 in the holder housing 80A is set such that the second exhaust filter 75, which is positioned in the left-right direction by the positioning wall 87, does not come into contact with the louver frame 1240 that protrudes to the right from the right side wall 123.

[0162] In the first opening 85 of the mounting wall 82 of the filter holder 80, the vertical distance between the fourth inner surface 85d and the third inner surface 85c is set to match the vertical distance between the upper frame 1240a and the lower frame 1240b of the louver frame 1240 on the right side wall. Furthermore, the front-to-back distance between the first inner surface 85a and the second inner surface 85b is set to match the front-to-back distance between the front frame 1240c and the rear frame 1240d of the louver frame 1240 on the right side wall.

[0163] Specifically, the vertical distance between the fourth inner surface 85d and the third inner surface 85c is slightly larger than the vertical distance between the upper frame 1240a and the lower frame 1240b, and the front-to-back distance between the first inner surface 85a and the second inner surface 85b is slightly larger than the front-to-back distance between the front frame 1240c and the rear frame 1240d. This makes it possible to fit the first opening 85 of the mounting wall 82 into the louver frame 1240.

[0164] When the louver frame 1240 is fitted into the first opening 85, the first inner surface 85a of the first opening 85 can come into contact with the front frame 1240c of the louver frame 1240, and the second inner surface 85b of the first opening 85 can come into contact with the rear frame 1240d of the louver frame 1240. In addition, the third inner surface 85c of the first opening 85 can come into contact with the upper frame 1240a of the louver frame 1240, and the fourth inner surface 85d can come into contact with the lower frame 1240b of the louver frame 1240.

[0165] The holder housing 80A can be attached to the right side wall 123, for example, using double-sided tape. In this case, the mounting wall 82 can attach the holder housing 80A to the right side wall 123 by adhering the double-sided tape attached to the adhesive portion 82a to the right side wall 123.

[0166] In this embodiment, the holder housing 80A is attached to the right side wall 123 using double-sided tape, but it can also be attached to the right side wall 123 by other methods, such as using hook-and-loop fasteners or adhesive.

[0167] As shown in Figure 21, when attaching the holder housing 80A supporting the second exhaust filter 75 to the right side wall 123, the first opening 85 of the mounting wall 82 of the holder housing 80A is fitted into the louver frame 1240 of the right side wall 123. Furthermore, with one of the first inner circumferential surfaces 85a and 2nd inner circumferential surfaces 85b and one of the third inner circumferential surfaces 85c and 4th inner circumferential surfaces 85d of the first opening 85 into which the louver frame 1240 is fitted, the mounting wall 82 is attached to the right side wall 123 with the louver frame 1240 in contact with the louver frame 1240.

[0168] As shown in Figures 21 and 22, in this embodiment, the holder housing 80A is attached to the right side wall 123 with the second inner surface 85b of the first opening 85 in contact with the rear frame 1240d of the louver frame 1240, and the third inner surface 85c of the first opening 85 in contact with the lower frame 1240b of the louver frame 1240.

[0169] However, it is also possible to attach the holder housing 80A to the right side wall 123 with the first inner surface 85a in contact with the front frame 1240c and the third inner surface 85c in contact with the lower frame 1240b. Furthermore, it is also possible to attach the holder housing 80A to the right side wall 123 with the first inner surface 85a in contact with the front frame 1240c and the fourth inner surface 85d in contact with the upper frame 1240a. In addition, it is also possible to attach the holder housing 80A to the right side wall 123 with the second inner surface 85b in contact with the rear frame 1240d and the fourth inner surface 85d in contact with the upper frame 1240a.

[0170] In this way, by bringing the inner surface of the first opening 85 into contact with the louver frame 1240, the holder housing 80A can be positioned relative to the right side wall 123 in a direction along the right side wall 123. This improves the positional accuracy of the filter holder 80 attached to the right side wall 123 relative to the louver 1241 in a direction along the right side wall 123.

[0171] In particular, by bringing the first inner surface 85a into contact with the front frame 1240c or the second inner surface 85b into contact with the rear frame 1240d, and then bringing the third inner surface 85c into contact with the lower frame 1240c or the fourth inner surface 85d into contact with the upper frame 1240a, the holder housing 80A can be positioned vertically and longitudinally with respect to the right side wall 123. This makes it easy to improve the positional accuracy of the filter holder 80 attached to the right side wall 123 relative to the louver 1241 in the direction along the right side wall 123.

[0172] Thus, the right side wall 123 has a louver frame 1240 as an outer protruding wall surrounding the outer circumference of the louver 1241, which makes it possible to improve the accuracy of the positional position of the filter holder 80 that supports the second exhaust filter 75 relative to the louver 1241. The louver frame 1240 is an example of a second positioning part that positions the filter holder in a direction along the side wall.

[0173] Furthermore, the louver frame 1240, which serves as an outer protruding wall for positioning the filter holder 80 that supports the second exhaust filter 75, and the first rib 1231, second rib 1232, third rib 1233, and fourth rib 1234, which serve as inner protruding walls for positioning the first exhaust filter 172, are all formed on the right side wall 123.

[0174] Therefore, it is possible to improve the precision of the positioning of the first exhaust filter 172 and the second exhaust filter 75. As a result, the air inside the housing 2A will pass through both the first exhaust filter 172 and the second exhaust filter 75 before being exhausted, allowing the functions of the first exhaust filter 172 and the second exhaust filter 75 to be fully performed.

[0175] As shown in Figure 23, when the cover 80B of the filter holder 80 attached to the right side wall 123 is removed from the holder housing 80A, the second opening 86 of the holder housing 80A is open, and the second exhaust filter 75 housed in the holder housing 80A is exposed to the outside through the second opening 86.

[0176] In this way, by removing the cover 80B from the holder housing 80A, the second exhaust filter 75 is exposed to the outside, making it easy to replace the second exhaust filter 75.

[0177] Here, the first exhaust filter 172 removes ozone contained in the passing air by decomposing it, making it less prone to clogging and thus tending to have a longer lifespan. On the other hand, the second exhaust filter 75 removes particulate matter contained in the passing air by capturing it, making it more prone to clogging, and thus its lifespan tends to be shorter than that of the first exhaust filter 172.

[0178] The second exhaust filter 75 has a shorter lifespan than the first exhaust filter 172 and therefore requires more frequent replacement. However, since the second exhaust filter 75 is housed in a filter holder 80 that is detachably attached to the right side wall 123, the replacement process can be made less complicated despite the higher replacement frequency. In particular, the second exhaust filter 75 can be easily replaced by removing the cover 80B of the filter holder 80, thus simplifying the replacement process.

[0179] (Modified version of the right wall) The right side wall 123 can also be formed as shown in Figure 24, as shown in right side wall 123-1. Right side wall 123-1 differs from right side wall 123 in that it has an exhaust port 123a-1, a louver 1241-1, and a louver frame 1240-1 instead of an exhaust port 123a, a louver 1241, and a louver frame 1240. Also, right side wall 123-1 differs from right side wall 123, which supports the first exhaust filter 172, in that it does not support the first exhaust filter 172. The other configurations of right side wall 123-1 are the same as those of right side wall 123.

[0180] Exhaust port 123a-1 is formed in the same way as exhaust port 123a. Louver 1241-1 is formed in the same way as louver 1241. Right side wall 123-1 is an example of a side wall having an exhaust port.

[0181] The louver frame 1240-1 surrounds the outer perimeter of the louver 1241-1 and is formed in a rectangular shape. The louver frame 1240-1 has an upper frame 1240a-1 located above the louver 1241-1, a lower frame 1240b-1 located below the louver 1241-1, a front frame 1240c-1 located in front of the louver 1241-1, and a rear frame 1240d-1 located behind the louver 1241-1.

[0182] The upper frame 1240a-1 and the lower frame 1240b-1 protrude to the right from the right side wall 123-1. The amount of protrusion of the upper frame 1240a-1 and the lower frame 1240b-1 from the right side wall 123-1 is smaller than the amount of protrusion of the upper frame 1240a and the lower frame 1240b of the louver 1241 from the right side wall 123. The front frame 1240c-1 and the rear frame 1240d-1 do not protrude to the right from the right side wall 123-1.

[0183] The filter holder 80 can be attached to the right side wall 123 by fitting the first opening 85 of the mounting wall 82 of the holder housing 80A into the louver frame 1240-1 of the right side wall 123-1.

[0184] As described above, the amount of protrusion of the upper frame 1240a-1 and lower frame 1240b-1 of the louver frame 1240-1 from the right side wall 123-1 is smaller than the amount of protrusion of the upper frame 1240a and lower frame 1240b of the louver frame 1240 from the right side wall 123, and the front frame 1240c-1 and rear frame 1240d-1 of the louver frame 1240-1 do not protrude from the right side wall 123-1. Therefore, even when the filter holder 80 is attached to the right side wall 123-1, the second exhaust filter 75 and the louver frame 1240-1 do not come into contact. [Explanation of Symbols]

[0185] 1, 1A Image forming device 2, 2A enclosure 5 Image forming unit 6. Fuser 23, 123 Right side wall 23a, 123a Exhaust port 54 Photosensitive drum 57. Charger 71,171 fans 72, 172 First exhaust filter 75. Second exhaust filter 80 Filter holder 80A Holder Housing 80B Cover 85 First opening 85a 1st inner surface 85b 2nd inner circumferential surface 85c 3rd inner surface 85d 4th inner surface 86. Second opening 231 First Rib 233 Second Rib 240, 1240 Louver frame 241 1241 Louver 1231 First Rib 1232 Second Rib 1233 Third Rib 1234 Fourth Rib 1240a Upper frame 1240b Bottom frame 1240c front frame 1240d rear frame S Seat

Claims

1. A housing having a side wall with an exhaust port, A fan for exhausting air from inside the enclosure, A first exhaust filter supported by the aforementioned side wall, A filter holder is provided that supports a second exhaust filter, which is sized to cover the aforementioned exhaust port, and is detachably attached to the side wall. Equipped with, The aforementioned side wall is A first positioning unit that contacts the first exhaust filter and positions the first exhaust filter in a direction along the side wall, An image forming apparatus characterized by having a second positioning unit that contacts the filter holder and positions the filter holder in a direction along the side wall.

2. The aforementioned side wall is The inner protruding wall, which serves as the first positioning portion, protrudes from the inner surface of the side wall toward the inside of the housing, The side wall has an outer protruding wall that protrudes outward from the outer surface of the side wall, which serves as a second positioning portion, The first exhaust filter is in contact with the inner protruding wall, The image forming apparatus according to claim 1, wherein the filter holder abuts against the outer protruding wall.

3. The aforementioned side wall is A louver that restricts the direction of exhaust of the air discharged through the aforementioned exhaust port, The image forming apparatus according to claim 2, further comprising a frame as the outer protruding wall surrounding the outer periphery of the louver.

4. The filter holder comprises a holder housing having a first opening and supporting the second exhaust filter, The image forming apparatus according to claim 3, wherein the frame of the side wall fits into the first opening, and the inner circumferential surface of the first opening in the holder housing abuts against the frame of the side wall.

5. The filter holder has a cover that is detachably attached to the holder housing, The holder housing has a second opening that is closed by the cover attached to the holder housing and is opened when the cover is removed from the holder housing. The image forming apparatus according to claim 4, wherein the second exhaust filter is exposed to the outside of the holder housing through the second opening when the cover is removed from the holder housing.

6. The frame of the side wall is circular in shape. The first opening of the holder housing is rectangular in shape. The inner circumferential surface of the first opening in the holder housing has a first surface extending along a first direction which is the direction along the side wall, and a second surface extending along a second direction which is perpendicular to the first direction. The image forming apparatus according to claim 4 or claim 5, wherein the first surface and the second surface are capable of contacting the frame.

7. The frame of the side wall has a first wall extending along a third direction which is the direction along the side wall, and a second wall extending along a fourth direction which is the direction along the side wall and perpendicular to the third direction. The inner circumferential surface of the first opening in the holder housing has a third surface extending along the third direction and a fourth surface extending along the fourth direction. The image forming apparatus according to claim 4 or claim 5, wherein the third surface is capable of contacting the first wall, and the fourth surface is capable of contacting the second wall.

8. The housing contains an image forming unit that forms an image on a sheet, The image forming unit comprises a drum for forming a toner image on a sheet, a charger for charging the drum, and a fuser for fixing the toner image formed on the sheet. The first exhaust filter is an ozone decomposition filter capable of decomposing ozone contained in the air passing through it, The image forming apparatus according to claim 1, wherein the second exhaust filter is a particulate filter capable of removing particulate matter contained in the air passing through it.

9. The image forming apparatus according to claim 1, wherein the second exhaust filter has a shorter lifespan than the first exhaust filter.

Images