JP2024029786A - Image forming device - Google Patents

Abstract

[Problem] In general, an electrophotographic image forming apparatus generally uses a method of fixing toner by applying heat and pressure to a recording medium. The mainstream method of cooling is air cooling, which uses airflow generated using a cooling fan. However, the operating noise generated by the cooling fan may leak to the outside of the image forming apparatus from the air intake port, which may worsen the noise for the user. A method of installing walls in the air flow path has been proposed as a countermeasure to the noise generated by fans, but depending on the size and shape of the walls, the cross-sectional area of the duct through which air can pass may be reduced, reducing the cooling effect. There is a possibility. SOLUTION: A first wall and a second wall are provided inside an intake duct for the purpose of reducing noise. The sum of the areas of the first opening formed by the first wall and the second opening formed by the second wall is larger than the area of the air inlet. [Selection diagram] Figure 8

Description

The present invention relates to an image forming apparatus and an image forming system.

2. Description of the Related Art Conventionally, electrophotographic image forming apparatuses have been widely applied as copying machines, printers, plotters, facsimile machines, and multifunctional machines having multiple functions thereof.

The electrophotographic image forming apparatus described above generally uses a fixing section to apply pressure and heat to the recording medium to fix the toner transferred to the recording medium.

However, even after the toner is fixed on the recording medium, the heat generated in the fixing section may remain and accumulate in the fixing section. If image formation is continued without eliminating the heat accumulated in the fixing section, there is a possibility that a fixing failure or the like may occur, which may affect image formation.

For this reason, the above-described image forming apparatus is generally provided with a cooling means for the fixing section. The mainstream cooling means is air cooling that uses airflow generated by a fan, and Patent Document 1 discloses a configuration in which air is taken in from an opening provided in the exterior of the image forming apparatus to cool the fixing unit. ing.

Japanese Patent Application Publication No. 2022-52309

However, in the configuration of the prior art, since the opening communicates with the outside of the image forming apparatus, there is a problem that the operation sound of the intake fan tends to leak from the opening, increasing noise to the user.

As a noise countermeasure against the operating noise of intake fans, it is known to install walls in the air flow path to reduce the noise generated by the fans, but depending on the shape and size of the walls, the air may There is a possibility that the cross-sectional area of the opening of the duct that can be passed through is reduced, and the cooling effect is reduced.

In view of the above problems, an object of the present invention is to reduce noise generated from the fan and perform effective cooling when a fixing unit is cooled by air cooling using a fan.

An image forming apparatus that forms an image on a recording medium,
a fixing unit that fixes the toner image on a recording medium;
a fan that cools the fixing section;
a duct having an intake port for sucking air from outside the image forming apparatus, and forming an air path for introducing the air taken in from the intake port to the fan;
Equipped with
The duct includes a first wall inside the duct at a first position in the intake direction in which air is directed from the intake port to the fan, and a second wall closer to the fan than the first direction in the intake direction. a second wall inside the duct at a position of
the first wall defines a first opening at the first location;
the second wall defines a second opening at the second location;
The total area of the first opening and the second opening is larger than the area of the intake port,
It is characterized by

According to the present invention, when the fixing unit is cooled by air cooling using a fan, noise generated from the fan can be reduced and effective cooling can be performed.

1 is a perspective view showing the entire image forming apparatus according to an embodiment of the present invention. 1 is a cross-sectional view showing the entire image forming apparatus according to an embodiment of the present invention. FIG. 3 is a perspective view of a paper discharge tray section in an embodiment of the present invention. FIG. 3 is a top view of the paper discharge tray section in the embodiment of the present invention. FIG. 4 is a sectional view taken along line AA in FIG. 4 of the conventional machine. FIG. 3 is a top view of a tray lower cover, a fixing device, a paper ejection tray, and a fixing device in a conventional machine. A diagram showing the operating noise and airflow paths in a conventional machine. FIG. 2 is a perspective view of a paper ejection tray and a lower tray cover in an embodiment of the present invention. FIG. 3 is a front view of the paper discharge tray section as viewed from the vent section in the embodiment of the present invention. The figure which showed the air path in the duct in embodiment of this invention. FIG. 5 is a cross-sectional view of FIG. 4 showing a duct opening in an embodiment of the present invention. FIG. 3 is a diagram showing the flow of fan noise in a duct in an embodiment of the present invention. FIG. 5 is a sectional view taken along line AA in FIG. 4 showing the arrangement of walls in the embodiment of the present invention. FIG. 4 is a sectional view taken along line AA in FIG. 4 showing a state in which the sound absorbing member according to the embodiment of the present invention is attached. FIG. 3 is a diagram showing the flow of fan noise in a duct in an embodiment of the present invention. The figure which showed the air path in the duct in embodiment of this invention. The figure which showed the shielding wall and the linear air path in embodiment of this invention.

[First embodiment]
(Schematic configuration of image forming apparatus)
Embodiments of the present invention will be described with reference to FIGS. 1 and 2.

In an image forming apparatus 1 according to an embodiment of the present invention, FIG. 1 shows a perspective view, and FIG. 2 shows a sectional view.

1 and 2, the image forming apparatus 1 includes a document reading section 41, a sheet supply section 42, a sheet transport section 43, an image forming section 44, a fixing section 45, and an operation section 46, and forms a toner image. Four photosensitive drums 6 are arranged. A charger, a developer, and a cleaner (not shown) are arranged around the photosensitive drum 6, and these constitute the image forming unit 3 as a process cartridge. The image forming unit 3 is configured as an image forming unit 44 which is an image forming means.

An intermediate transfer belt 7 serving as intermediate transfer means is disposed above the image forming unit 44 so as to be in contact with each photosensitive drum 6.

The photoreceptor drums 6 are each charged by a charger (not shown) and exposed by the exposure unit 2 to form a latent image on the photoreceptor drums 6. Each latent image is developed by a developing device (not shown), and a toner image replenished by a toner replenishing section is formed on the photoreceptor drum 6.

As the photoreceptor drum 6 rotates, the toner image arrives at the primary transfer means 5 where the photoreceptor drum 6 and the intermediate transfer belt 7 are in contact with each other. The toner images are sequentially transferred onto the intermediate transfer belt 7 by the primary transfer means 5 disposed opposite to each photoreceptor drum 6 . A primary transfer bias is applied to the primary transfer means 5 from an electrical equipment board (not shown).

The sheets S stored in a paper feeding unit 42 serving as a paper feeding means are sent out one by one by a pickup roller. After timing is adjusted by the registration rollers 9, the sheet S is conveyed to a nip portion constituted by the secondary transfer roller 8 and the intermediate transfer belt 7, and the toner image on the intermediate transfer belt 7 is secondarily transferred onto the sheet S. Thereafter, the sheet S on which the toner image has been transferred is conveyed to the fixing device 45, where it is fixed by applying heat and pressure, whereby the toners are melted and mixed to form a printed image fixed on the sheet S. The paper is discharged onto the paper discharge tray 24 by the discharge conveyance means 18 provided downstream of the fixing device 45 .

The reversing unit for reversing the fixed sheet S transports the second-transferred sheet S to the secondary transfer section again by the reversing transport roller 17, and then transports it to the fixing device 45, and discharges the sheet S by the ejection transport means 18. The paper is discharged onto the paper tray 24.

(About the duct inside the conventional internal paper output tray)
Before describing the embodiments of the present invention, the configuration of a duct formed by the paper discharge tray 24 and the lower tray cover 25 will be described. FIG. 3 is a perspective view showing the appearance of the paper discharge tray 24 and tray lower cover 25 assembled together, and FIG. 4 is a top view. FIG. 5 is a sectional view taken along line AA in FIG. The paper discharge tray 24 is attached on the lower tray cover 25 as shown in FIG. The paper ejection tray has a paper ejection tray front side 30, a paper ejection tray rear side 31, and a paper ejection section 53 from which a recording medium on which an image is formed is ejected. An internal space 32 is formed by a paper discharge tray 24 having a paper discharge tray front side surface 30, a paper discharge tray rear surface 31, a paper discharge section 53, and a tray lower cover 25. Although details will be described later, the internal space 32 constitutes a duct. That is, the paper discharge section 53 corresponds to the top surface, the tray lower cover 24 corresponds to the bottom surface, the paper discharge tray front side surface 30 corresponds to the first side wall surface, and the paper discharge tray rear surface 31 corresponds to the second side wall surface.

A first intake port 22 is formed on one side of the paper discharge tray 24, and the outside air is connected to the internal space 32. Further, the tray lower cover 25 is formed with a second air intake port 23 that is connected to the inside of the machine. This provides a duct configuration that connects the inside of the machine to the outside of the image forming apparatus.

As shown in FIG. 7A, a blowing fan 21 is disposed adjacent to this duct to cool a part of the fixing section 45. Further, FIG. 7(c) shows a straight air path 27 through which the fan 21 takes in air from the intake port 22. That is, the first intake port 22 corresponds to an intake port, and the air taken in by the intake port is introduced from the intake port 22 to the fan 21 .

However, although this configuration allows outside air to be taken in for cooling, there is a possibility that operating noise, such as fan operating sound V1 shown in Figure 7(b), leaks outside the machine and may have a noise impact on the surrounding environment. be.

(About the wall shape that increases the sound insulation effect)
In the first embodiment of the present invention, a wall shape that enhances the sound insulation effect against fan operation noise will be described with reference to FIGS. 8 to 13.

FIG. 8A is a perspective view of the tray lower cover 25 before the first wall 26a, the second wall 26b, and the paper discharge tray 24 are attached. FIG. 8(b) is a perspective view of the tray lower cover 25 with the first wall 26a and the second wall 26b attached. FIG. 8(c) is a perspective view of the state shown in FIG. 8(b) with the paper discharge tray 24 attached to the tray lower cover. That is, the first wall 26a and the second wall 26b are attached inside the duct.

The first wall 26a and the second wall 26b are walls for blocking the operating noise of the fan, and are arranged on the tray lower cover 25.

It is preferable that each of the first wall 26a and the second wall 26b in FIG. 17 be arranged approximately at right angles to the straight air path 27 (air path).

9 is a front view of the first air intake port 22. FIG. The first wall 26a is arranged with a gap between it and the front side surface 30 of the paper discharge tray so as not to create air intake resistance for the fan. Similarly, the second wall 26b is disposed with a gap from the rear side surface 31 of the paper discharge tray so as not to create air intake resistance for the fan. However, the first wall 26a and the second wall 26b may be arranged in opposite positions to the above arrangement.

The first air intake port 22 is arranged at a position where the first wall 26a, the second wall 26b, or both can be seen throughout the entire area when the inside of the machine is viewed from the outside front. This is because the two walls block the operating sound of the fan coming out from the second intake port 23 so that it does not flow in a straight line. That is, in the intake direction that is the direction from the intake port 22 toward the fan 21, the second wall 26b is located closer to the fan 21 than the first wall 26a. Note that the arrangement of the first wall 26a and the second wall 26b in the intake direction is not limited to this, and the first wall 26a may be arranged closer to the fan 21 than the second wall 26b.

(About the two wall attachment methods)
The first wall 26a and the second wall 26b may be attached to the inside of the paper discharge tray 24 instead of being attached to the tray lower cover 25. Further, the first wall 26a and the second wall 26b may not be separate bodies, but may be integrally molded from the tray lower cover 25 or the paper discharge tray 24 in a rib shape. Furthermore, in the case of integral molding, depending on the rib height, each rib may be divided into upper and lower parts, and the lower tray cover 25 and the paper discharge tray 24 may be integrally molded.

Further, FIG. 13 is a cross section taken along the line AA in FIG. 4, and shows a state in which the first wall 26a and the second wall 26b are arranged. As shown in FIG. 13, the first wall 26a may be attached to the tray lower cover 25, the second wall 26b may be attached to the paper discharge tray 24, and the walls extending from above and below may be arranged alternately.

(About the duct opening)
Next, the configuration as an intake duct from outside air will be explained.

As shown in FIG. 10, outside air is taken into the machine through an air path 37 indicated by an arrow inside the duct. The air path is in a meandering state due to the first wall 26a and the second wall 26b. In order to avoid intake resistance, the arrangement of the two walls is determined by the opening area of the duct.

The duct opening 35 and the duct opening 36 in the shaded areas shown in FIGS. 11(a) and 11(b) are formed in the shape and arrangement of the first wall 26a and the second wall 26b, respectively. Therefore, by configuring the wall so that the total area of each of the duct opening 35 and the duct opening 36 is larger than the total opening area of the first intake port 22, a decrease in intake efficiency can be avoided. That is, the duct opening 35 corresponds to the first opening, and the duct opening 36 corresponds to the second opening.

(About wall shape to improve sound insulation effect)
FIG. 12 is a top view showing two walls that enhance the sound insulation effect of fan operation noise.

The fan operation sound V1 coming out of the second intake port 23 hits the first wall 26a and the second wall 26b and is trapped inside the machine as reflected sound V2, making it difficult for it to come out of the machine from the first intake port 22.

[Second embodiment]
(When attaching sound absorbing members to the first and second walls)
A second embodiment of the present invention will be explained using FIG. 14.

A sound absorbing member 38 can also be attached to the first wall 26a and the second wall 26b described above in order to further enhance the soundproofing effect. FIG. 14 is a cross section taken along the line AA in FIG. 4, and shows a state in which sound absorbing members are attached to the first wall 26a and the second wall 26b. An adhesive is attached to one side of the sound absorbing member 38, and the sound absorbing member 38 is pasted on the surfaces of the two walls (the sides facing the direction in which the fan 21 is arranged). The fan operating sound V1 is absorbed when it hits the sound absorbing member 38 attached to the first wall 26a and the second wall 26b, and even if it is reflected, it becomes smaller as reflected sound V2, and the operating sound of the fan 21 is attenuated. Since the noise is reflected inside the duct, the operation noise of the fan 21 emitted to the outside of the machine becomes even smaller.

[Third embodiment]
(When changing the arrangement angle of the first wall and second wall)
A third embodiment of the present invention will be explained using FIG. 15.

The angle at which the first wall 26a and the second wall 26b are arranged can be changed to improve the sound insulation effect. 15 and 16 are top views of the duct section, with the paper discharge tray 24 not attached. Further, the first wall 26a and the second wall 26b are arranged at angles of θ1 and θ2, respectively. θ1 and θ2 are each set at an acute angle in a range of approximately 90° to less than 120°. As shown in FIG. 15, when the fan operation sound V1 is reflected by the first wall 26a and the second wall 26b, it is reflected at angles θ3 and θ4, respectively. Therefore, the reflected sound V2 is reflected in a direction away from the path connecting to the outside air of the duct formed by the first wall 26a and the second wall 26b, so that the operating sound of the fan 21 is less likely to leak outside the machine. The reflection angles θ3 and θ4 are each expressed by the following equations.

θ3=(θ1-90)×2
θ4=(θ2-90)×2
Further, since the first wall and the second wall are arranged at an obtuse angle of θ1 and θ2, the straight air path 27 shown in FIG. 16 hits the first wall 26a and connects with the first wall 26a in the intake direction. Since the contact angle θ5 is an obtuse angle, the intake resistance is smaller than when the contact is made at a right angle, and the cooling efficiency of the fan is also improved.

Moreover, the same can be said about the second wall 26b.

1 Image forming apparatus 11 Fixing roller 21 Fan 22 First vent section 23 Second vent section 24 Paper discharge tray 25 Tray lower cover 26 Shielding wall 26a First wall 26b Second wall 28 Air path 30 Paper discharge Front side of tray 31 Rear side of paper ejection tray 32 Internal space 33 Duct 35 Duct opening 36 Duct opening 37 Air path 38 Sound absorbing material 45 Fixing section 53 Paper ejection section

Claims (4)

An image forming apparatus that forms an image on a recording medium,
a fixing unit that fixes the toner image on a recording medium;
a fan that cools the fixing section;
a duct having an intake port for sucking air from outside the image forming apparatus, and forming an air path for introducing the air taken in from the intake port to the fan;
Equipped with
The duct includes a first wall inside the duct at a first position in the intake direction in which air is directed from the intake port to the fan, and a second wall closer to the fan than the first direction in the intake direction. a second wall inside the duct at a position;
the first wall defines a first opening at the first location;
the second wall defines a second opening at the second location;
The total area of the first opening and the second opening is larger than the area of the air intake port,
An image forming apparatus characterized by: The image forming apparatus includes:
Equipped with a paper output tray with an internal space,
The paper ejection tray has the air intake port,
the internal space of the paper output tray is the duct;
The image forming apparatus according to claim 1, characterized in that: The duct includes a first side wall surface, a side wall surface, a bottom surface, and a top surface,
The first wall is arranged from the bottom surface to the top surface and from the first side wall surface toward the second side wall surface,
The second wall is arranged from the bottom surface to the top surface and from the second side wall surface toward the first side wall surface.
The image forming apparatus according to claim 1, characterized in that: The first wall has a sound absorbing member on a surface close to the fan in the intake direction,
The second wall has a sound absorbing member on a surface close to the fan in the intake direction.
The image forming apparatus according to claim 1, characterized in that:

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