Image forming apparatus

1 . An image forming apparatus, comprising:

a housing including a sidewall in which an exhaust port is formed;

a fan;

a duct extending in an exhaust direction and configured to house the fan, the duct including a downstream end in the exhaust direction; and

an exhaust filter disposed between the downstream end of the duct and the exhaust port in the exhaust direction, the exhaust filter including a first surface facing the exhaust port and a second surface facing the downstream end of the duct,

wherein dimensions of the downstream end of the duct in directions orthogonal to the exhaust direction are smaller than dimensions of the exhaust filter in the directions orthogonal to the exhaust direction, and

wherein the downstream end of the duct faces the second surface of the exhaust filter in the exhaust direction,

wherein the sidewall includes:

a recess that is recessed toward a downstream side in the exhaust direction; and

a louver disposed downstream of the recess and the exhaust filter in the exhaust direction,

wherein an outer peripheral surface of the exhaust filter directly contacts, around an entire periphery of the exhaust filter, an inner wall surface of the recess.

2 . The image forming apparatus according to claim 1 ,

wherein the exhaust filter is configured to reduce ozone from air exhausted.

3 . The image forming apparatus according to claim 1 ,

wherein the first surface of the exhaust filter is in contact with an upstream end of the louver in the exhaust direction.

4 . The image forming apparatus according to claim 1 , further comprising a seal,

wherein the seal is disposed between an outer peripheral surface of the fan and an inner peripheral surface of the duct.

5 . The image forming apparatus according to claim 1 ,

wherein the duct includes a hook that projects toward the fan and engages with the fan to position the fan in the exhaust direction.

6 . The image forming apparatus according to claim 1 ,

wherein the duct includes a cutout extending through a peripheral wall of the duct in one of directions orthogonal to the exhaust direction and through which a harness connected to the fan passes.

7 . The image forming apparatus according to claim 1 ,

further comprising a process unit accommodated in the housing and configured to form a toner image on a sheet, wherein the fan exhausts air that has passed through the process unit.

8 . The image forming apparatus according to claim 7 ,

further comprising an intermediate filter disposed between the process unit and the duct.

9 . The image forming apparatus according to claim 8 ,

wherein the intermediate filter is a filter configured to reduce ozone from the air exhausted by the fan.

10 . The image forming apparatus according to claim 1 ,

further comprising an image forming engine configured to form an image on a sheet by an electrophotographic system, the image forming engine including:

a photosensitive drum;

a charger configured to charge the photosensitive drum;

an exposure device configured to expose the photosensitive drum to form an electrostatic latent image;

a developing device configured to develop the electrostatic latent image with toner to form a toner image; and

a transfer unit configured to transfer the toner image formed on the photosensitive drum onto the sheet,

a process unit accommodating part configured to accommodate the image forming engine;

a power supply board;

a board accommodating part configured to accommodate the power supply board;

a first exhaust port and a second exhaust port extending through a sidewall of the housing disposed downstream of the fan in the exhaust direction and intersecting with an axial direction of the photosensitive drum; and

a process duct including a first opening that faces the first exhaust port and a second opening that is open into the process unit accommodating part, the process duct being configured to guide air inside the process unit accommodating part from the second opening to the first opening,

wherein the housing accommodates the image forming engine, the process unit accommodating part, and the power supply board,

wherein the board accommodating part includes a third opening that faces the second exhaust port,

wherein the fan includes:

a first fan facing the first exhaust port and configured to exhaust air inside the process duct through the first opening to outside of the housing, and

a second fan facing the second exhaust port and configured to exhaust air inside the board accommodating part through the second opening to the outside of the housing, and

wherein the exhaust filter includes:

a first exhaust filter provided at the first exhaust port downstream of the first fan in the exhaust direction; and

a second exhaust filter provided at the second exhaust port downstream of the second fan in the exhaust direction.

11 . The image forming apparatus according to claim 10 ,

wherein the first exhaust filter includes an ozone filter that reduces ozone in the air.

12 . The image forming apparatus according to claim 10 ,

wherein the second exhaust filter includes an ozone filter that reduces ozone in the air.

13 . The image forming apparatus according to claim 10 ,

wherein the sidewall includes an intake port through which air outside the housing flows into the process unit accommodating part, and

the housing includes a third fan that is provided in the intake port and configured to suck the air outside the housing into the housing.

14 . The image forming apparatus according to claim 10 ,

further comprising a fuser configured to fix the toner image transferred onto the sheet to the sheet,

wherein the process duct is disposed between the image forming engine and the fuser in a sheet conveyance direction in which the sheet is conveyed by a conveyer, and

wherein the board accommodating part is disposed below the fuser in a vertical direction.

15 . The image forming apparatus according to claim 1 ,

further comprising an image forming engine configured to form an image on a sheet by an electrophotographic system, the image forming engine including:

a photosensitive drum;

a charger configured to charge the photosensitive drum;

an exposure device configured to expose the photosensitive drum to form an electrostatic latent image;

a developing device configured to develop the electrostatic latent image with toner to form a toner image; and

a transfer unit configured to transfer the toner image formed on the photosensitive drum onto the sheet,

a process unit accommodating part configured to accommodate the image forming engine;

a first exhaust port extending through a sidewall of the housing disposed downstream of the fan in the exhaust direction and intersecting with an axial direction of the photosensitive drum; and

a process duct including a first opening that faces the first exhaust port and a second opening that is open into the process unit accommodating part, the process duct being configured to guide air inside the process unit accommodating part from the second opening to the first opening,

wherein the housing accommodates the image forming engine and the process unit accommodating part,

wherein the process duct includes an intermediate filter disposed in the second opening,

wherein the fan includes a first fan facing the first exhaust port and configured to exhaust air inside the process duct through the first opening to outside of the housing, and

wherein the exhaust filter includes a first exhaust filter provided at the first exhaust port downstream of the first fan in the exhaust direction.

16 . The image forming apparatus according to claim 15 ,

wherein the intermediate filter includes an ozone filter that reduces ozone in the air.

17 . The image forming apparatus according to claim 1 ,

wherein the downstream end of the duct directly contacts the second surface of the exhaust filter in the exhaust direction.

18 . An image forming apparatus, comprising:

a housing in which an exhaust port is formed;

a fan;

a duct extending in an exhausting direction and configured to accommodate the fan, the duct including a downstream end in the exhausting direction;

an exhaust filter disposed between the duct and the exhaust port in the exhausting direction, the exhaust filter including a first surface facing the exhaust port and a second surface facing the duct; and

a flow path extending from an opening formed on a top surface of the housing up to the downstream end of the duct, the flow path allowing liquid on the top surface of the housing to flow up to the downstream end of the duct by gravity,

wherein dimensions of a perimeter of the downstream end of the duct each orthogonal to the exhaust direction are smaller than dimensions of the exhaust filter each orthogonal to the exhaust directions, and

wherein the perimeter of the downstream end of the duct in the exhaust direction is in contact with the second surface of the exhaust filter such that the perimeter of the downstream end of the duct in the exhaust direction is up against the second surface of the exhaust filter.

19 . The image forming apparatus according to claim 18 ,

wherein the flow path includes:

a first flow path formed to the duct and extending in a vertical direction; and

a second flow path formed to the duct continuously with a lower end of the first flow path and formed below the fan to extend between the fan and the exhaust port.

20 . An image forming apparatus, comprising:

a fan;

a duct extending in an exhaust direction and configured to house the fan, the duct including a downstream end in the exhaust direction;

a sidewall disposed downstream of the fan in the exhaust direction, the sidewall including an exhaust port extending through the sidewall; and

an exhaust filter disposed between the downstream end of the duct and the exhaust port, the exhaust filter including a first surface facing the exhaust port and a second surface facing the downstream end of the duct,

wherein the downstream end of the duct faces the second surface of the exhaust filter in the exhaust direction,

wherein the exhaust filter has an area greater than a cross-sectional area of the downstream end of the duct, and

wherein the duct, the exhaust filter, and the exhaust port fluidly communicate with each other,

wherein the sidewall includes:

a recess that is recessed toward a downstream side in the exhaust direction; and

a louver disposed downstream of the recess and the exhaust filter in the exhaust direction,

wherein an outer peripheral surface of the exhaust filter directly contacts, around an entire periphery of the exhaust filter, an inner wall surface of the recess.