Image forming apparatus with ventilation guides for exhausting air and method associated with the same

According to one embodiment, there is provided an image forming apparatus including a fixing portion, an exterior member, a first ventilation guide, a second ventilation guide, and a blowing portion. The exterior member has a first opening portion opened to an outside. The first ventilation guide is disposed between the fixing portion and the exterior member. The first ventilation guide forms a first space communicating with the first opening portion between the first ventilation guide and the exterior member. The second ventilation guide is disposed between the fixing portion and the first ventilation guide, and has a second opening portion. The second ventilation guide forms a second space communicating with the second opening portion between the second ventilation guide and the first ventilation guide.

FIELD

Embodiments described herein relate generally to an image forming apparatus and methods associated therewith.

BACKGROUND

An exterior member of an image forming apparatus may become warm due to heat emitted from a fixing portion or the like of the image forming apparatus. Generally, the hot exterior member is disposed at a position away from an operator to avoid injury.

However, from the viewpoint of downsize of the image forming apparatus, there is an increased chance that the image forming apparatus has a configuration in which the hot exterior member is positioned near the operator.

DETAILED DESCRIPTION

An image forming apparatus of an embodiment has a fixing portion, an exterior member, a first ventilation guide, a second ventilation guide, and a blowing portion. The exterior member has a first opening portion opened to an outside. The first ventilation guide is disposed between the fixing portion and the exterior member. The first ventilation guide forms a first space communicating with the first opening portion between the first ventilation guide and the exterior member. The second ventilation guide is disposed between the fixing portion and the first ventilation guide. The second ventilation guide has a second opening portion positioned closer to the fixing portion than the first space. The second ventilation guide forms a second space communicating with the second opening portion between the second ventilation guide and the first ventilation guide. The blowing portion exhausts air inside the first space and the second space.

Hereinafter, the image forming apparatus of the embodiment will be described with reference to the drawings. Here, first, “front”, “rear”, “left”, and “right” in the embodiment are defined. “Front” means a side closer to an operator standing at a position where characters of a control panel16of an image forming apparatus1appear in a correct orientation than a center portion of an inside of the image forming apparatus1. On the other hand, “rear” means a side farther to an operator standing at the position where characters of the control panel16appear in the correct orientation than the center portion of the inside of the image forming apparatus1. “Left” and “right” respectively means “left” and “right” with respect to the operator standing at the position where characters of the control panel16appear in the correct orientation. In the drawings described below, a front side is referred to as “front”, a rear side is referred to as “rear”, a left side is referred to as “left, and a right side is referred to as “right”.

First Embodiment

FIG. 1is a perspective view schematically illustrating an appearance of an image forming apparatus1of the first embodiment. InFIG. 1, a scanner portion12is not illustrated.FIG. 2is a block diagram illustrating a system configuration example of the image forming apparatus1. For example, the image forming apparatus1is a Multi Function Peripheral (MFP). However, the image forming apparatus1is not limited to the above example and may be a copy machine, a printer, or the like.

The image forming apparatus1of the embodiment is, for example, a front rolling type image forming apparatus. After an image is formed while a sheet S passes through a position close to an operator on an inside of the image forming apparatus1, the sheet S is discharged in a direction away from the operator (see an arrow P inFIG. 1). Therefore, a component such as a fixing portion22which is relatively high in temperature and a transporting path through which the heated sheet S passes are disposed on a side close to the operator on the inside of the image forming apparatus1. However, the image forming apparatus1is not limited to the front rolling type image forming apparatus.

First, an entire configuration of the image forming apparatus1will be described.

As illustrated inFIGS. 1 and 2, for example, the image forming apparatus1includes a housing11, the scanner portion12, a paper feeding portion13, a printer portion14, a paper discharge portion15, a control panel16, and a control portion17.

The housing11forms an outer shell of the image forming apparatus1. For example, the housing11accommodates the paper feeding portion13, the printer portion14, the paper discharge portion15, and the control portion17. In addition, the housing11has a front portion11aand a rear portion11b. The front portion11ais a region that is positioned at a position closer to an operator standing at a position where characters of the control panel16appear in the correct orientation than a center portion of the inside of the image forming apparatus1. On the other hand, the rear portion11bis a region that is positioned at a position farther to the operator standing at the position where characters of the control panel16appear in the correct orientation than the center portion of the inside of the image forming apparatus1.

The paper feeding portion13includes a paper feeding cassette, a manual feeding tray13a, and a pickup roller. The manual feeding tray13acan be opened and closed with respect to the housing11. The sheet S is loaded while the manual feeding tray13ais in an opened state with respect to the housing11. The pickup roller sends the sheet S loaded on the manual feeding tray13ato the printer portion14.

The printer portion14forms an image on the sheet S based on image data. The printer portion14includes a transfer portion21and the fixing portion (fixing device)22. The transfer portion21includes an electrostatic charger, a photoconductive drum, an exposure unit, a developing device, and a transfer roller. The transfer portion21transfers a toner image formed on a surface of the photoconductive drum to the sheet S. The fixing portion22includes a heat roller22aand a press roller22b(seeFIG. 3). The fixing portion22heats and presses the sheet S passing between the heat roller22aand the press roller22b. The sheet S to which the toner image is transferred is heated and pressed, and thereby the fixing portion22fixes the toner image on the sheet S. In the embodiment, the fixing portion22is disposed at the front portion11aof the housing11.

The paper discharge portion15includes a first paper discharge guide15a, a second paper discharge guide15b, and paper discharge rollers15c(seeFIG. 3). A part of a transporting path T, in which the sheet S is transported, is formed between the first paper discharge guide15aand the second paper discharge guide15b. The transporting path T includes a transporting path Ta which is formed from the paper feeding portion13to the paper discharge portion15through the printer portion14, and a transporting path Tb (reverse path) through which the sheet S passes during double-sided printing. The paper discharge rollers15cdischarge the sheet S passing between the first paper discharge guide15aand the second paper discharge guide15bto the outside of the housing11. In addition, the paper discharge rollers15cis rotated reversely during double-sided printing, thereby sending the sheet S to the transporting path Tb (reverse path).

Returning toFIG. 1, the control panel16has a display portion26and an input receiving portion27. The display portion26includes a display screen. Various types of information are displayed on the display portion26. The input receiving portion27includes a plurality of buttons. The input receiving portion27receives inputs of various operation instructions. However, the input receiving portion27may be realized by a touch panel (touch sensor) provided on the display screen.

The control portion17controls the entire image forming apparatus1. For example, the control portion17controls operations of the scanner portion12, the paper feeding portion13, the printer portion14, the paper discharge portion15, and the control panel16.

Next, a cooling structure30provided in the image forming apparatus1of the embodiment will be described.FIG. 3is a sectional view that is taken along line F3-F3of the image forming apparatus1illustrated inFIG. 1. As illustrated inFIG. 3, the cooling structure30includes a top cover31, a stay member32, a heat exhaust path forming member33, and a blowing portion34(seeFIG. 5).

First, the top cover31will be described.

The top cover31is an example of a “first exterior member”. The top cover31forms a part of the outer shell of the image forming apparatus1as a part of the housing11. For example, the top cover31forms a part of an upper surface (upper surface of the housing11) of the image forming apparatus1. The top cover31is disposed in the front portion11aof the housing11. The top cover31is disposed above the fixing portion22. For example, the top cover31is provided across an entire width of the housing11so as to extend between a left end portion and a right end portion of the housing11(seeFIG. 1).

In the embodiment, the top cover31has an upper wall31a, a front wall31b, and a rear wall31c. The upper wall31aextends substantially horizontally. The front wall31bextends obliquely downward of a front side from a front end portion of the upper wall31a. On the other hand, the rear wall31cextends obliquely downward of a rear side from a rear end portion of the upper wall31a. Therefore, the top cover31is formed in a recessed shape of which a lower side is opened.

The top cover31has at least one (for example, plural) first opening portion41that is opened to the outside (outside of the housing11) of the image forming apparatus1. For example, the first opening portion41is provided on the front wall31bof the top cover31.

Here, in the embodiment, the control panel16is disposed above the top cover31. For example, the control panel16has a first surface16aand a second surface16b. The first surface16aincludes the display portion26and the input receiving portion27. The second surface16bis positioned on a side opposite to the first surface16a. The front wall31bof the top cover31faces the second surface16bof the control panel16. A gap ga is provided between the front wall31bof the top cover31and the second surface16bof the control panel16.

Viewed from another viewpoint, as illustrated inFIG. 1, the top cover31has a first end portion31e1and a second end portion31e2. For example, the first end portion31e1is a left end portion of the top cover31. The second end portion31e2is a right end portion of the top cover31. Therefore, the control panel16is disposed closer to the first end portion31e1of the top cover31than a center portion of the top cover31in a width direction of the housing11. The “width direction of the housing” is a direction from the first end portion31e1to the second end portion31e2of the top cover31. If the control panel16is disposed closer to one of the right and left ends of the top cover31, it is easy for the operator to reach out to the paper discharge portion15behind the control panel16as viewed from the operator. For example, if the control panel16is disposed closer to the left end portion of the top cover31, the operator can easily extend the right hand, which is a dominant hand of many operators, to the paper discharge portion15.

FIG. 4is a perspective view illustrating the top cover31in a state where the control panel16is removed. As illustrated inFIG. 4, for example, a plurality of first opening portions41are provided in a region of the top cover31which is covered by the control panel16when the control panel16is viewed in a front view. “When the control panel is viewed in a plan view” means, for example, a case where the control panel16is viewed from a direction substantially perpendicular to the display portion26. In addition, in the embodiment, equal to or greater than half of the plurality of first opening portions41is positioned closer to the first end portion31e1of the top cover31than the center portion of the top cover31in the width direction (longitudinal direction of the top cover31) of the housing11.

Next, the stay member32will be described.

The stay member32is an example of a “first ventilation guide”. The “ventilation guide” referred to in the present application is not limited to a member that forms a duct. The “ventilation guide” broadly means a member that guides a flow of air. For example, the “ventilation guide” is not necessarily provided over an entire length and an entire width of a space to be a ventilation path, and may also be a member that is partially provided for the entire length and the entire width of the space to be the ventilation path. In other words, the “ventilation guide” may be a member that defines at least a part of the ventilation path.

FIG. 5is a perspective view illustrating the stay member32in a state where the top cover31is removed. As illustrated inFIG. 5, the stay member32is one of reinforcing members for reinforcing the image forming apparatus1. For example, the image forming apparatus1has a first structure member51that is provided at the left end portion of the housing11and a second structure member52that is provided at the right end portion of the housing11. The stay member32extends between the first structure member51and the second structure member52so as to connect the first structure member51and the second structure member52. For example, the stay member32is a plate-like sheet metal member extending along a substantially horizontal direction. In addition, viewed from another viewpoint, the stay member32is also a base member to which the control panel16is attached. A support member53(for example, a fixed bracket) that supports the control panel16is attached to the stay member32(seeFIG. 3).

As illustrated inFIG. 3, the stay member32is disposed between the fixing portion22and the top cover31. The stay member32faces an internal space of the top cover31from a lower side. Therefore, a first space S1, which is at least a part of a first ventilation path through which cooling air flows, is formed between the stay member32and the top cover31. For example, the first space S1is a space surrounded by the upper wall31a, the front wall31b, and the rear wall31cof the top cover31, and the stay member32. The first space S1communicates with the first opening portion41of the top cover31. The first space S1is formed along an inner surface of the top cover31. The first space S1is formed along the longitudinal direction of the top cover31.

Next, the heat exhaust path forming member33will be described.

The heat exhaust path forming member33is an example of a “second ventilation guide”.

FIG. 6is a perspective view illustrating the heat exhaust path forming member33in a state where the top cover31and the stay member32are removed. As illustrated inFIG. 6, the heat exhaust path forming member33is a member that forms a heat exhaust path exhausting air that is heated by the sheet S passing through the fixing portion22and the transporting path T to the outside of the image forming apparatus1. The heat exhaust path forming member33extends in the width direction of the housing11.

The heat exhaust path forming member33has at least one (for example, plural) second opening portion42that is opened to the inside of the housing11. In the embodiment, a plurality of second opening portions42are arranged in the width direction of the housing11. The plurality of second opening portions42are disposed at substantially equally to the left and right with respect to the center portion of the housing11in the width direction of the housing11.

As illustrated inFIG. 3, the heat exhaust path forming member33is disposed between the stay member32and the fixing portion22. The heat exhaust path forming member33has a first bottom wall portion33a, a second bottom wall portion33b, a first upright wall33c, and a second upright wall33d. The first bottom wall portion33ais inclined with respect to a horizontal surface so as to follow an inclination of the transporting path T of the sheet S (for example, so as to follow the first paper discharge guide15a). For example, the first bottom wall portion33ais inclined so as to be positioned downward as the first bottom wall portion33aadvances to the front side of the housing11. The second bottom wall portion33bis positioned on the front side of the housing11than the first bottom wall portion33a. The second bottom wall portion33bis inclined with respect to the horizontal surface so as to follow a part of an outer shape of Automatic Duplex Copy Unit (ADU unit) U which is described in a second embodiment in detail. The second bottom wall portion33bis inclined so as to be positioned upward as the second bottom wall portion33badvances to the front side of the housing11. The first bottom wall portion33aand the second bottom wall portion33bare respectively inclined so that an internal space of the heat exhaust path forming member33is formed to be relatively wide. The first upright wall33cextends above from a rear end portion of the first bottom wall portion33a. The second upright wall33dextends above from a front end portion of the second bottom wall portion33b. Therefore, the heat exhaust path forming member33is formed in a recessed shape of which an upper side is opened.

The plurality of second opening portions42are provided in the first bottom wall portion33aof the heat exhaust path forming member33. The plurality of second opening portions42are positioned closer to the fixing portion22than the first space S1. The second opening portion42is positioned above from the fixing portion22and the transporting path T. For example, the second opening portion42is positioned above at least a part of the fixing portion22. The second opening portion42is opened downward. The second opening portion42communicates with the transporting path T through a gap gb between the first paper discharge guide15aand the ADU unit U, and the like. In addition, the second opening portion42communicates with at least a part of a space in a periphery of the fixing portion22through the transporting path T.

As illustrated inFIG. 3, the heat exhaust path forming member33is disposed between the fixing portion22and the stay member32. The stay member32faces the internal space of the heat exhaust path forming member33from above. Therefore, a second space S2, which is at least a part of the second ventilation path through which exhaust hot air flows, is formed between the heat exhaust path forming member33and the stay member32. For example, the second space S2is a space surrounded by the stay member32, the first bottom wall portion33a, the second bottom wall portion33b, the first upright wall33c, and the second upright wall33dof the heat exhaust path forming member33. The second space S2communicates with the second opening portion42of the heat exhaust path forming member33. The second space S2is formed along the inner surface of the heat exhaust path forming member33. For example, the second space S2is formed along a longitudinal direction of the top cover31.

At least one of the stay member32and the heat exhaust path forming member33has a partition wall W1that partitions between the first space S1and the second space S2. The partition wall W1forms a boundary portion between the first space S1and the second space S2. In the embodiment, the partition wall W1is formed by the stay member32. The partition wall W1is positioned on a side opposite to the transporting path T of the sheet S with respect to the first bottom wall portion33aof the heat exhaust path forming member33. In other words, the partition wall W1is positioned farther away from the first bottom wall portion33aof the heat exhaust path forming member33with respect to the transporting path T of the sheet S. The partition wall W1is an example of a “first wall”. The first bottom wall portion33aof the heat exhaust path forming member33is an example of a “second wall”.

Next, the blowing portion34will be described.

The blowing portion34is formed of at least one fan. For example, the blowing portion34is adjacent to the second end portion31e2of the top cover31. The blowing portion34faces the first space S1and the second space S2in the width direction of the housing11. The blowing portion34exhausts air on the inside of the first space S1and the second space S2to the outside of the image forming apparatus1. For example, the blowing portion34exhausts air on the inside of the first space S1and the second space S2to the right side of the image forming apparatus1. However, the blowing portion34may be formed by a plurality of fans.

Next, an operation of the image forming apparatus1of the embodiment will be described.

In the embodiment, when the blowing portion34is driven, as illustrated by an arrow A1inFIG. 3, cold air on the outside of the housing11flows into the first space S1from the first opening portion41through the gap ga between the front wall31bof the top cover31and the second surface16bof the control panel16as cooling air. Therefore, as illustrated by an arrow A1inFIG. 5, air flowing into the first space S1from the first opening portion41flows through the first space S1along the longitudinal direction of the top cover31. Some of air flowing into the first space S1from the first opening portion41flows along the inner surface of the top cover31. Therefore, cooling of the top cover31is promoted. In addition, some of air flowing into the first space S1from the first opening portion41flows along the partition wall W1that partitions between the first space S1and the second space S2. Therefore, cooling of the partition wall W1is promoted. Air flowing through the first space S1is exhausted by the blowing portion34from the first space S1to the outside of the image forming apparatus1.

In addition, when the blowing portion34is driven, as illustrated by an arrow B1inFIG. 3, air positioned in a periphery of the fixing portion22and the transporting path T flows into the second space S2from the second opening portion42as exhaust hot air. Therefore, as illustrated by an arrow B1inFIG. 6, air flowing into the second space S2from the second opening portion42flows through the second space S2along the longitudinal direction of the top cover31. Air flowing through the second space S2is exhausted by the blowing portion34from the second space S2to the outside of the image forming apparatus1.

According to the configuration described above, a cooling performance of the image forming apparatus1can be enhanced.

Here, for example, according to the front rolling type image forming apparatus1, it is easy to downsize the image forming apparatus1. Furthermore, according to the front rolling type image forming apparatus1, it is easy to access necessary components when paper jam occurs. On the other hand, according to the front rolling type image forming apparatus1, the fixing portion22and the transporting path T through which the heated sheet S passes are disposed in positions adjacent to the operator. Therefore, the top cover31and the control panel16relatively adjacent to the operator become warm. However, in order to cool the top cover31and the control panel16, if cooling air is simply introduced into the housing11, a temperature of the fixing portion22may decrease. If the temperature of the fixing portion22decreases, power consumption of the fixing portion22increases.

Therefore, in the embodiment, the image forming apparatus1includes the stay member32, the heat exhaust path forming member33, and the blowing portion34. The stay member32is disposed between the fixing portion22and the top cover31. The stay member32forms the first space S1communicating with the outside between the stay member32and the top cover31. The heat exhaust path forming member33is disposed between the fixing portion22and the stay member32. The heat exhaust path forming member33has the second opening portion42that is positioned closer to the fixing portion22than the first space S1. The heat exhaust path forming member33forms the second space S2communicating with the second opening portion42between the heat exhaust path forming member33and the stay member32. The blowing portion34exhausts air on the inside of the first space S1and the second space S2.

According to the configuration described above, the ventilation path of a two-layer structure is formed in the inside of the housing11. Therefore, cold air of the outside of the housing11flows into the first space S1, which is a first layer, as cooling air and thereby it is possible to efficiently cool the top cover31. In addition, cooling air flows through the first space S1and thereby the boundary portion (partition wall W1) between the first space S1and the second space S2can be cooled. Therefore, heat is unlikely to be transferred from warm air within the housing11to the top cover31and the control panel16. Therefore, it is possible to suppress an increase in the temperature of the top cover31and the control panel16.

In addition, warm air in the periphery of the fixing portion22flows into the second space S2, which is a second layer, and exhausts to the outside as exhaust hot air. Therefore, it is possible to suppress that the boundary portion (partition wall W1) between the first space S1and the second space S2is continuously heated by warm air in the periphery of the fixing portion22. Therefore, it is possible to suppress an increase in the temperature of the boundary portion (partition wall W1) between the first space S1and the second space S2. In addition, warm air in the periphery of the fixing portion22flows into the second space S2that is positioned between the first space S1and the fixing portion22. Therefore, it is possible to suppress that the periphery of the fixing portion22is cooled by cooling air flowing through the first space S1. Therefore, a decrease in the temperature of the fixing portion22is suppressed and it is possible to suppress an increase in power consumption.

Here, air within the housing11contains moisture evaporated from the sheet S as the sheet S is heating by the fixing portion22, and thus has a relatively high humidity. Therefore, when there is a temperature difference in the flow of a plurality of types of air flowing through the housing11, moisture in air condenses in the boundary portion between a space through which warm air flows and a space through which cold air flows. Therefore, water droplets may adhere to the boundary portion. For example, in the embodiment, the water droplets adhere to the boundary portion (partition wall W1) between the first space S1and the second space S2due to the dew condensation.

Therefore, in the embodiment, the boundary portion (partition wall W1) between the first space S1and the second space S2is disposed on a side opposite to the transporting path T of the sheet S with respect to the first bottom wall portion33aof the heat exhaust path forming member33in which the second opening portion42is provided. In other words, the partition wall W1on which the dew condensation occurs is disposed at a position deep with respect to the transporting path T of the sheet S. That is, the boundary portion (partition wall W1) between the first space S1and the second space S2is formed by a wall different from a wall forming the transporting path T of the sheet S. Therefore, it is possible to suppress that moisture adheres to the sheet S passing through the transporting path T.

In the embodiment, the first opening portion41is provided at a position which is covered by the control panel16. Therefore, the first opening portion41is unlikely to be seen from the operator. Therefore, it is possible to enhance an appearance of the image forming apparatus1. Furthermore, if the first opening portion41is provided at a position which is covered by the control panel16, it is possible to reduce a possibility of accidentally dropping objects in the first opening portion41. Furthermore, if the first opening portion41is provided at the position which is covered by the control panel16, some of air flowing into the first opening portion41also comes into contact with the control panel16as forced convection air. Therefore, it is possible to more efficiently cool the control panel16.

Second Embodiment

Next, a second embodiment will be described with reference toFIGS. 7 to 16. The second embodiment is different from the first embodiment in that a ventilation path is also formed behind a front cover61. Moreover, in the second embodiment, configurations other than the following description are the same as those in the first embodiment. Therefore, the same reference numerals are given to the configurations having the same or similar functions and duplicate explanation will be omitted.

FIG. 7is a sectional view illustrating an image forming apparatus1of the second embodiment.

As illustrated inFIG. 7, a cooling structure30of the image forming apparatus1of the embodiment includes a top cover31, a stay member32, a heat exhaust path forming member33, an ADU unit U, a first sponge member81, a second sponge member82, and a blowing portion34.

The ADU unit U includes a front cover61, a ventilation path forming member62, a transport guide63, and a transport roller64.

First, the front cover61will be described.

The front cover61is an example of a “second exterior member”. The front cover61forms a part of an outer shell of the image forming apparatus1as a part of a housing11. The front cover61extends along a substantially perpendicular direction. For example, the front cover61forms a part of a front surface (front surface of the housing11) of the image forming apparatus1. At least a part of the front cover61is arranged in a substantially the horizontal direction with a fixing portion22.

In the embodiment, the front cover61has a recessed portion61athat accommodates a manual feeding tray13a(seeFIG. 1). The recessed portion61ais recessed rearward from a surface of the front cover61. The manual feeding tray13ais rotatable around a rotation portion61bprovided at a lower end portion of the manual feeding tray13a. The manual feeding tray13ais movable between an accommodated position which is accommodated in the recessed portion61aand a using position which projects to an outside of the recessed portion61a. The front cover61has a ceiling surface61c(upper surface) which forms an upper end portion of the recessed portion61a. A gap gc is formed between the ceiling surface61cand a leading end portion of the manual feeding tray13aas a gap for opening and closing the manual feeding tray13a. The gap gc is substantially 3 mm.

The front cover61has at least one (for example, plural) third opening portion43that is opened to the outside (outside of the housing11) of the image forming apparatus1. For example, the third opening portion43is provided on the ceiling surface61cof the front cover61. The third opening portion43is opened downward. The third opening portion43is positioned at a lower end portion of a third space S3which is described below.

FIG. 8is a view of the front cover61as seen from obliquely downward.

As illustrated inFIG. 8, a plurality of third opening portions43are arranged in a width direction of the housing11in the ceiling surface61cof the front cover61. Since the third opening portion43is provided on the ceiling surface61cof the front cover61, it is difficult to see from the operator.

Next, a ventilation path forming member62will be described.

The ventilation path forming member62is an example of a “third ventilation guide”.

FIG. 9is a perspective view illustrating a ventilation path forming member62in a state where a transport guide63which is described below is removed. As illustrated in FIG.9, the ventilation path forming member62is attached to an inner surface of the front cover61. For example, the ventilation path forming member62is provided at a center portion of the front cover61in the width direction of the housing11. The ventilation path forming member62has a rear wall62a, a first side wall62b, and a second side wall62c. The rear wall62ais away from the inner surface of the front cover61. For example, the first side wall62bextends from a left end portion of the rear wall62ato the front cover61. The second side wall62cextends from a right end portion of the rear wall62ato the front cover61. Therefore, the ventilation path forming member62is formed in a recessed shape of which a front side is opened.

As illustrated inFIG. 7, the ventilation path forming member62is disposed between the front cover61and the fixing portion22. The front cover61faces the internal space of the ventilation path forming member62from the front side. Therefore, the third space S3, which is at least a part of a third ventilation path through which cooling air flows, is formed between the ventilation path forming member62and the front cover61. For example, the third space S3is a space surrounded by the rear wall62a, the first side wall62b, and the second side wall62cof the ventilation path forming member62, and the front cover61. The third space S3communicates with the third opening portion43of the front cover61. The third space S3is formed along the inner surface of the front cover61. For example, the third space S3is formed along a perpendicular direction.

Here, the third space S3communicates with the first space S1described above. Hereinafter, an example of a communication structure causing the third space S3and the first space S1to communicate with each other will be described.

As illustrated inFIG. 7, the heat exhaust path forming member33has a projection portion33ewhich is positioned between the ventilation path forming member62and the top cover31. The projection portion33ehas at least one (for example, plural) first hole71communicating with the first space S1. The first hole71is positioned above the ventilation path forming member62.

FIG. 10is a perspective view illustrating the stay member32and the heat exhaust path forming member33in a state where the top cover31is removed. As illustrated inFIG. 10, a plurality of first holes71are arranged in the width direction of the housing11.

On the other hand, as illustrated inFIG. 7, the upper end portion of the ventilation path forming member62has at least one (for example, plural) second hole72communicating with the third space S3. The second hole72faces the first hole71of the heat exhaust path forming member33. A plurality of second holes72are arranged in the width direction of the housing11so as to correspond to the plurality of first holes71. Therefore, the third space S3communicates with the first space S1through the first hole71and the second hole72. The second hole72is an example of an opening portion causing the third space S3and the first space S1to communicate with each other. Here, for example, a sum of opening areas of the plurality of second holes72is greater than a sum of opening areas of the plurality of third opening portions43. Therefore, pressure loss is unlikely to occur within the third space S3.

Next, the transport guide63will be described.

The transport guide63is an example of a “fourth ventilation guide”.

FIG. 11is a perspective view illustrating the transport guide63. As illustrated inFIG. 11, the transport guide63is attached to the inner surface of the front cover61or the ventilation path forming member62so as to cover the ventilation path forming member62. For example, the transport guide63is provided at a center portion of the front cover61in the width direction of the housing11. The transport guide63has a rear wall63a, a first side wall63b, and a second side wall63c. The rear wall63ais away from the rear wall62aof the ventilation path forming member62. The rear wall63adefines one surface of the transporting path Tb (reverse path) of the sheet S during double-sided printing. That is, the rear wall63acomes into contact with the sheet S during double-sided printing thereby guiding the sheet S. The first side wall63bextends from the left end portion of the rear wall63ato the front cover61. The second side wall63cextends from the right end portion of the rear wall63ato the front cover61. Therefore, the transport guide63is formed in a recessed shape of which a front side is opened.

As illustrated inFIG. 7, the rear wall63aof the transport guide63has at least one (for example, plural) fourth opening portion44which is opened to the inside of the housing11. In the embodiment, a plurality of fourth opening portions44are arranged in the width direction of the housing11. The fourth opening portion44is opened closer to the fixing portion22than the third space S3. The fourth opening portion44communicates with the transporting path Tb. For example, the fourth opening portion44is directly exposed to the transporting path Tb. The fourth opening portion44communicates with at least a part of a space of a periphery of the fixing portion22through the transporting path T. For example, the fourth opening portion44is provided at a position above from the fixing portion22.

As illustrated inFIG. 7, the transport guide63is disposed between the ventilation path forming member62and the fixing portion22. The ventilation path forming member62faces the internal space of the transport guide63from the front side. Therefore, a fourth space S4, which is at least a part of a fourth ventilation path through which exhaust hot air flows, is formed between the transport guide63and the ventilation path forming member62. For example, the fourth space S4is a space surrounded by the rear wall63a, the first side wall63b, and the second side wall63cof the transport guide63, and the ventilation path forming member62. The fourth space S4communicates with the fourth opening portion44of the transport guide63. The fourth space S4is formed along the inner surface of the transport guide63. For example, the fourth space S4is formed along a perpendicular direction.

At least one of the ventilation path forming member62and the transport guide63has a partition wall W2that partitions between the third space S3and the fourth space S4. The partition wall W2forms a boundary portion between the third space S3and the fourth space S4. In the embodiment, the partition wall W2is formed by the ventilation path forming member62. The partition wall W2is positioned on a side opposite to the transporting path T of the sheet S with respect to the rear wall63aof the transport guide63. In other words, the partition wall W2is positioned farther away from the rear wall63aof the transport guide63with respect to the transporting path T of the sheet S. The partition wall W2is an example of the “third wall”. The rear wall63aof the transport guide63is an example of the “fourth wall”.

Here, the fourth space S4communicates with the second space S2described above. Hereinafter, an example of a communication structure causing the fourth space S4and the second space S2to communicate with each other will be described.

As illustrated inFIG. 7, the second bottom wall portion33bof the heat exhaust path forming member33has at least one (for example, plural) third hole73communicating with the second space S2. The third hole73is positioned above the transport guide63.

FIG. 12is a perspective view illustrating the heat exhaust path forming member33in a state where the top cover31and the stay member32are removed. As illustrated inFIG. 12, a plurality of third holes73are arranged in the width direction of the housing11. The heat exhaust path forming member33has a partition wall W3that is upright at a position between the first hole71and the third hole73. The partition wall W3partitions between the first hole71and the third hole73.

On the other hand, as illustrated inFIG. 7, an upper end portion of the transport guide63has at least one (for example, plural) fourth hole74communicating with the fourth space S4. The fourth hole74faces the third hole73of the heat exhaust path forming member33. A plurality of fourth holes74are arranged in the width direction of the housing11so as to correspond to the plurality of third holes73. Therefore, the fourth space S4communicates with the second space S2through the third hole73and the fourth hole74. The fourth hole74is an example of the opening portion causing the fourth space S4and the second space S2to communicate with each other. Here, for example, a sum of opening areas of the plurality of fourth holes74is greater than a sum of opening areas of the plurality of fourth opening portions44. Therefore, pressure loss is unlikely to occur within the fourth space S4.

The ADU unit U described above is rotatable with respect to a remaining portion of the image forming apparatus1around a rotation shaft Ua provided at a lower end portion of the ADU unit U (seeFIG. 7). Therefore, for example, when paper jam occurs, the operator rotates the ADU unit U to the front side of the housing11to access the inside of the housing11.

In the embodiment, in order to allow the rotation of the ADU unit U, a first gap g1is formed between the heat exhaust path forming member33and the ventilation path forming member62(between the top cover31or the stay member32and the ventilation path forming member62). Similarly, in order to allow the rotation of the ADU unit U, a second gap g2is formed between the heat exhaust path forming member33and the transport guide63. The first gap g1and the second gap g2are respectively closed by a first sponge member81and a second sponge member82.

Next, the first sponge member81will be described.

The first sponge member81is an example of a “first elastic member”. For example, the first sponge member81is positioned between the top cover31and the ventilation path forming member62. In the embodiment, the first sponge member81is positioned between the projection portion33eof the heat exhaust path forming member33and the ventilation path forming member62to be positioned between the top cover31and the ventilation path forming member62. The first sponge member81is sandwiched between the heat exhaust path forming member and the ventilation path forming member62, and is elastically deformed between the heat exhaust path forming member33and the ventilation path forming member62. Therefore, the first sponge member81closes the first gap g1between the heat exhaust path forming member33and the ventilation path forming member62in the periphery of the first hole71and the second hole72. The first sponge member81has a first communication port81acausing the first hole71and the second hole72to communicate with each other. The third space S3communicates with the first space S1through the second hole72of the ventilation path forming member62, the first communication port81aof the first sponge member81, and the first hole71of the heat exhaust path forming member33.

FIG. 13is a perspective view illustrating the first sponge member81.FIG. 13is a view in which the heat exhaust path forming member33, to which the first sponge member81is attached, is viewed from obliquely downward. As illustrated inFIG. 13, the first sponge member81is attached to a lower surface of the heat exhaust path forming member33. For example, the first sponge member81is fixed to the lower surface of the heat exhaust path forming member33by adhesive, a double-sided tape, or the like.

Next, the second sponge member82will be described.

The second sponge member82is an example of a “second elastic member”. The second sponge member82is positioned between the heat exhaust path forming member33and the transport guide63. The second sponge member82is sandwiched between the heat exhaust path forming member33and the transport guide63, and is elastically deformed between the heat exhaust path forming member33and the transport guide63. Therefore, the second sponge member82closes the second gap g2between the heat exhaust path forming member33and the transport guide63in the periphery of the third hole73and the fourth hole74. The second sponge member82has a second communication port82acausing the third hole73and the fourth hole74to communicate with each other. The fourth space S4communicates with the second space S2through the fourth hole74of the transport guide63, the second communication port82aof the second sponge member82, and the third hole73of the heat exhaust path forming member33.

FIG. 14is a perspective view illustrating the second sponge member82.FIG. 14is a view in which the heat exhaust path forming member33, to which the second sponge member82is attached, is viewed from obliquely downward. As illustrated inFIG. 14, the second sponge member82is attached to a lower surface of the heat exhaust path forming member33. For example, the second sponge member82is fixed to the lower surface of the heat exhaust path forming member33by adhesive, a double-sided tape, or the like.

Next, an operation of the image forming apparatus1of the embodiment will be described.

In the embodiment, when the blowing portion34is driven, as illustrated by an arrow A2inFIG. 15, cold air of the outside of the housing11flows into the third space S3from the third opening portion43as cooling air in addition to the flow of air of the arrow A1explained in the first embodiment. Therefore, air flowing into the third space S3from the third opening portion43flows into the third space S3upward. Some of air flowing into the third space S3from the third opening portion43flows along the inner surface of the front cover61. Therefore, cooling of the front cover61is promoted. In addition, some of air flowing into the third space S3from the third opening portion43flows along the partition wall W2that partitions between the third space S3and the fourth space S4. Therefore, cooling of the partition wall W2is promoted. Air flowing through the third space S3flows into the first space S1through the second hole72of the ventilation path forming member62, the first communication port81aof the first sponge member81, and the first hole71of the heat exhaust path forming member33. Air flowing into the first space S1merges with air flowing into the first space S1through the first opening portion41and exhausts to the outside of the image forming apparatus1.

In addition, when the blowing portion34is driven, as illustrated by an arrow B2inFIG. 16, some of air that is positioned in the periphery of the fixing portion22and the transporting path T flows into the fourth space S4from the fourth opening portion44as exhaust hot air in addition to the flow of air of the arrow B1explained in the first embodiment. Therefore, air flowing into the fourth space S4from the fourth opening portion44flows into the fourth space S4upward. Air flowing into the fourth space S4flows into the second space S2through the fourth hole74of the transport guide63, the second communication port82aof the second sponge member82, and the third hole73of the heat exhaust path forming member33. Air flowing into the second space S2merges with air flowing into the second space S2through the second opening portion42and exhausts to the outside of the image forming apparatus1.

According to the configuration described above, it is possible to further efficiently cool the image forming apparatus1. That is, in the embodiment, the ventilation path forming member62is disposed between the fixing portion22and the front cover61. The ventilation path forming member62forms the third space S3communicating with the outside between the ventilation path forming member62and the front cover61. The transport guide63is disposed between the fixing portion22and the ventilation path forming member62. The transport guide63has a fourth opening portion44that is positioned closer to the fixing portion22than the third space S3. The transport guide63forms the fourth space S4communicating with the fourth opening portion44between the transport guide63and the ventilation path forming member62.

According to the configuration described above, the ventilation path of a two-layer structure is also formed in the front surface portion of the housing11. Therefore, cold air of the outside of the housing11flows into the third space S3, which is a first layer, as cooling air and thereby it is possible to efficiently cool the front cover61. In addition, cooling air flows through the third space S3and thereby the boundary portion (partition wall W2) between the third space S3and the fourth space S4can be cooled. Therefore, heat is unlikely to be transferred from warm air within the housing11to the front cover61. Therefore, it is possible to suppress an increase in the temperature of the front cover61.

In addition, warm air in the periphery of the fixing portion22flows into the fourth space S4, which is a second layer, and exhausts to the outside as exhaust hot air. Therefore, it is possible to suppress an increase in the temperature of the boundary portion (partition wall W2) between the third space S3and the fourth space S4. In addition, warm air in the periphery of the fixing portion22flows into the fourth space S4that is positioned between the third space S3and the fixing portion22. Therefore, it is possible to suppress that the periphery of the fixing portion22is cooled by cooling air flowing through the third space S3. Therefore, a decrease in the temperature of the fixing portion22is suppressed and it is possible to suppress an increase in power consumption.

Here, in the embodiment, the water droplets adhere to the boundary portion (partition wall W2) between the third space S3and the fourth space S4due to the dew condensation. Therefore, in the embodiment, the boundary portion (partition wall W2) between the third space S3and the fourth space S4is disposed on a side opposite to the transporting path T of the sheet S with respect to the rear wall63aof the transport guide63in which the fourth opening portion44is provided. In other words, the partition wall W2on which the dew condensation occurs is disposed at a position deep with respect to the transporting path T of the sheet S. That is, the boundary portion (partition wall W2) between the third space S3and the fourth space S4is formed by a wall different from a wall forming the transporting path T of the sheet S. Therefore, it is possible to suppress that moisture adheres to the sheet S passing through the transporting path T.

In the embodiment, the third opening portion43is provided at the ceiling surface61cforming the upper end portion of the recessed portion61aof the front cover61. Therefore, the third opening portion43is unlikely to be seen from the operator. Therefore, it is possible to enhance an appearance of the image forming apparatus1.

In the embodiment, the first sponge member81is not attached to the ventilation path forming member62but attached to the heat exhaust path forming member33. Therefore, even if the ADU unit U is opened, the first sponge member81remains on the inside of the housing11. Therefore, it is possible to prevent the operator from erroneously removing the first sponge member81. This also applies to the second sponge member82.

Above, the image forming apparatus1of the first and the second embodiments is described, but the embodiments are not limited to the examples described above. For example, in the embodiments described above, the top cover31and the heat exhaust path forming member33are formed in the recessed shape. Instead thereof, the stay member32may be formed in the recessed shape so as to face the first space51or the second space S2from a plurality of directions. Similarly, the front cover61may be formed in the recessed shape so as to face the third space S3from a plurality of directions. In addition, the ventilation path forming member62may be formed in the recessed shape so as to face the fourth space S4from a plurality of directions.

For example, instead of the heat exhaust path forming member33, the first hole71may be provided in the top cover31or the stay member32. Instead of the ventilation path forming member62, the second hole72may be provided in the front cover61. Instead of the heat exhaust path forming member33, the third hole73may be provided in the stay member32. Instead of the transport guide63, the fourth hole74may be provided in the ventilation path forming member62.

Furthermore, the first sponge member81may be positioned between at least one of the top cover31and the stay member32, and at least one of the front cover61and the ventilation path forming member62. The second sponge member82may be positioned between at least one of the stay member32and the heat exhaust path forming member33, and at least one of the ventilation path forming member62and the transport guide63.

According to at least one embodiment described above, the first ventilation guide in which the first space is formed between the first exterior member and the first ventilation guide, and the second ventilation guide in which the second space is formed between the first ventilation guide and the second ventilation guide are provided. Therefore, it is possible to improve cooling efficiency of the image forming apparatus.