JP6929166B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a printer that forms an image by an electrophotographic method, an electrostatic recording method, or the like.

In the electrophotographic image forming apparatus, a fixing apparatus for fixing an unfixed toner image formed on a recording material is provided. The fixing device is generally a heating device that heat-fixes an unfixed toner image by heating a recording material (paper, sheet material, etc.). For example, a heat roller type fixing device has a heat roller having a heater inside and a pressure roller that presses against the heat roller, and carries an unfixed toner image at a fixing nip portion that is a pressure contact portion of both rollers. The recorded material is sandwiched and transported. Then, the recording material and the toner image are heated and pressurized at the fixing nip portion, and the toner image is fixed to the recording material. The recording material conveyed from the fixing device is discharged to the paper ejection section in the single-sided image forming mode, and is conveyed to the double-sided conveying section in the double-sided image forming mode (automatic double-sided mode).

In an image forming apparatus provided with such a heating type fixing device, as in Patent Document 1, a fan for cooling a sheet after fixing that has been heated by heating by the fixing device may be provided.

Further, Patent Document 2 discloses an image forming apparatus including the above fan. The image forming apparatus is provided with an operation unit and a display unit at a position adjacent to a paper ejection unit on the upper surface of the apparatus main body of the image forming apparatus above the fixing device.

Japanese Unexamined Patent Publication No. 2016-335545 Japanese Unexamined Patent Publication No. 2006-72200

It is known that when the recording material is heated by using the fixing device described above, water vapor is generated by evaporating the water contained in the recording material. Therefore, when a cooling device for cooling the recording material after fixing is provided as in Patent Document 1, water vapor flows downstream in the sheet transport direction due to the air blown from the fan and is exhausted from the sheet discharge port. However, depending on the amount of water vapor generated, it may not be sufficient to exhaust the air from the seat discharge port, and water vapor may accumulate in the transport path. In this way, when water vapor accumulates in the transport path, water droplets adhere to the transport guide and the like, and dew condensation occurs, and moisture adheres to the recording material after image formation that is transported in the device, and the recording material becomes dirty. There is a risk that it will end up.

On the other hand, in order to prevent water vapor from accumulating in the transport path, it is conceivable to provide an exhaust port for exhausting water vapor to the outside of the device in addition to the sheet discharge port. However, when an exhaust port is provided in addition to the seat discharge port, it is difficult to provide an exhaust port on the upper part of the fixing device in a configuration in which the operation unit is provided on the upper part of the fixing device as in Patent Document 2. Further, if the exhaust port is provided at a position on the upper part of the device different from the position where the operation unit is provided, the exhaust port is provided at a position visually recognizable by the user, so that the appearance quality of the device is deteriorated.

Therefore, the present invention provides an image forming apparatus capable of preventing stains due to adhesion of water droplets to a recording material by more efficiently suppressing dew condensation due to water vapor generated from the fixing apparatus without deteriorating the appearance quality. The purpose is to provide.

An image forming apparatus having an image forming means for forming an image on a recording material, heating the record material on which the image is formed by the image forming unit, a fixing unit configured to fix an image on a recording material, said fixing means A first cover member that covers at least the upper part of the fixing means and constitutes an upper surface of the image forming apparatus, and a first cover member of the first cover member. The first cover member includes a second cover member having a second engaging portion that engages with the engaging portion and provided with an input means for receiving input from the user, and the first cover member is the second cover member. a supporting portion and the the engaging portion first engagement portion to support said second cover member in engagement, communicates with the space between the fixing means and the discharge port, of the space has an exhaust port for exhausting air out of the apparatus, the said second cover member is extended beauty, have a low had extended portion than the height in the vertical direction the supporting portion on the lower side in the vertical direction The exhaust port is provided between the support portion and the extension portion in a direction intersecting the vertical direction in a state where the first engaging portion and the second engaging portion are engaged with each other. It is characterized by being able to be.

According to the present invention, it is possible to prevent the recording material from being contaminated due to the adhesion of water droplets by more efficiently suppressing dew condensation due to water vapor generated from the fixing device without deteriorating the appearance quality.

The schematic block diagram of the image forming apparatus which concerns on embodiment. The perspective view of the operation unit which concerns on embodiment. (A) A perspective view of the operation unit as viewed from the upper surface side. (B) A perspective view of the operation unit as viewed from the lower surface side. The perspective view of the exterior cover member which concerns on embodiment. (A) A perspective view of the entire exterior cover member. (B) An enlarged perspective view of a portion of the exterior cover member to which the operation unit cover is mounted. The perspective view which showed the fixing method of the operation unit which concerns on embodiment. (A) State before fixing the operation unit. (B) The state after fixing the operation unit. A cross-sectional view taken along the line AA of FIG. 4 (B). (A) A cross-sectional view showing a state in which the operation unit is moved in the direction of arrow V1. (B) A cross-sectional view showing a state in which the operation unit is moved in the direction of arrow V2. The perspective view of the vicinity of the discharge double-sided transport part which concerns on embodiment. FIG. 5 is a cross-sectional view of the vicinity of the discharge double-sided transport portion according to the embodiment.

The best embodiments for carrying out the present invention will be illustrated in detail below with reference to the drawings. However, the dimensions, materials, shapes, etc. of the components described in this embodiment should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions, and the invention of the present invention. It is not intended to limit the scope to the following embodiments.

[Structure of image forming apparatus main body]
FIG. 1 is a schematic configuration diagram of a cross section of the image forming apparatus 100 according to the present embodiment. The image forming apparatus 100 of the present embodiment has an SFP (Single Factor) configuration having only a function of forming an image on a recording material. As shown in FIG. 1, the image forming apparatus 100 is an intermediate transfer type full-color printer in which four cartridges 7a, 7b, 7c, and 7d as image forming portions are arranged along the upper surface of the intermediate transfer belt 5. The four cartridges 7a to 7d are configured to be substantially the same except that the toner colors used are different from yellow, magenta, cyan, and black. In the following, one of the four cartridges 7a to 7d will be described as the cartridge 7, and the other cartridges will be represented by reference numerals in parentheses to omit duplicate description.

The four cartridges 7 (7a to 7d) arranged side by side in the vertical and oblique directions are a photosensitive drum unit 26 (26a to 26d) having a photosensitive drum 1 (1a to 1d) as an electrophotographic photosensitive member, and a developing unit 4 (4a to 4a to). 4d) is provided.

The photosensitive drum 1 is rotationally driven clockwise (Q direction) in FIG. 1 by a driving member (not shown). Further, around the photosensitive drum 1, cleaning members 6 (6a to 6d), charging rollers 2 (2a to 2d), and a developing unit 4 are arranged in the order of their rotation directions.

The cleaning member 6 removes the toner agent remaining on the photosensitive drum 1 after the toner image formed on the photosensitive drum 1 is transferred onto the intermediate transfer belt 5. The toner agent removed by the cleaning member 6 is collected in the removal toner chamber in the photosensitive unit 26 (26a to 26d).

Further, the charging roller 2 uniformly charges the surface of the photosensitive drum 1. After the surface of the photosensitive drum 1 is charged by the charging roller 2, the laser beam is exposed to the surface of the photosensitive drum 1 from the scanner unit (exposure means) 3 through the unit openings 32 (32a to 32d). As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 1. In this embodiment, the scanner unit 3 is arranged below the cartridge 7.

Further, the developing unit 4 is for supplying toner to the electrostatic latent image formed on the photosensitive drum 1 and developing the electrostatic latent image as a toner image. The developing unit 4 has a developing roller 25 (25a to 25d) that comes into contact with the photosensitive drum 1 and supplies toner to the surface of the photosensitive drum 1, and a supply roller 34 that comes into contact with the developing roller 25 and supplies toner to the developing roller 25. (34a to 34d) are provided.

When forming an image on the recording material S, first, the electrostatic latent image formed on the surface of the photosensitive drum 1 by the scanner unit 3 is developed as a toner image by the cartridge 7 and transferred to the intermediate transfer belt 5.

The intermediate transfer belt 5 is stretched on the drive roller 10 and the tension roller 11 and is driven in the direction of arrow R in FIG. Further, a primary transfer roller 12 (12a to 12d) is arranged inside the intermediate transfer belt 5 so as to face each photosensitive drum 1 (1a to 1d), and a transfer bias is applied by a bias applying means (not shown). It is configured to be.

For example, when a negatively charged toner is used, a positive electrode bias is applied to the primary transfer roller 12, so that the toner image is sequentially transferred onto the intermediate transfer belt 5. Then, the toner images of the four colors are transferred to the secondary transfer unit 15 in a state where the toner images of the four colors are overlapped on the intermediate transfer belt 5.

At this time, the toner remaining on the intermediate transfer belt 5 after the secondary transfer to the recording material S is removed by the transfer belt cleaning device 23, and the removed toner passes through a waste toner transfer path (not shown). It is collected in a waste toner collection container (not shown).

On the other hand, in synchronization with the image forming operation described above, the recording material S is fed to the secondary transfer unit 15 by a transport mechanism including a feeding device 13 and a resist roller pair 17.

The feeding device 13 includes a feeding cassette 24 for storing a plurality of recording materials S, a feeding roller 8 for feeding the recording material S, and a feeding roller 8 for feeding the recording material S fed to the feeding roller 8. It has a pair of 16.

The feeding cassette 24 is detachably configured from the image forming apparatus 100. The user pulls out the feeding cassette 24, removes it from the image forming apparatus 100, sets the recording material S, and inserts the recording material S into the image forming apparatus 100 to complete the replenishment of the recording material S.

Of the recording materials S stored in the feeding cassette 24, the feeding roller 8 is pressed against the recording material S located at the highest position, and is separated one by one by the separation pad 9 as the feeding roller 8 rotates (friction). Single separation method) The recording material S is transported to the downstream side in the transport direction.

Then, the recording material S conveyed from the feeding device 13 is conveyed from the lower side to the upper side of the image forming apparatus 100 by the resist roller pair 17 along the conveying path extending in the vertical direction of the image forming apparatus 100, and the secondary transfer unit 15 Will be transported to. In the secondary transfer unit 15, by applying a positive electrode bias to the secondary transfer roller 18, the four-color toner image on the intermediate transfer belt 5 can be secondarily transferred to the transferred recording material S. It is possible.

Then, the recording material S conveyed from the secondary transfer unit 15 is conveyed to the fixing device 14 as a fixing means provided on the upper part of the image forming apparatus 100, and the image transferred to the recording material S by the fixing device 14 is transferred. The image is fixed on the recording material S by heating and pressurizing.

In the single-sided image forming mode, the recording material S on which the toner image is fixed passes through the lower part of the sorting member 40, is discharged from the discharge port 190 to the discharge tray 20 by the discharge roller pair 19, and is loaded. The discharge tray 20 is an example of a loading unit.

In this way, the recording material S supplied by the feeding device 13 is conveyed to the transport path extending in the vertical direction of the image forming apparatus 100, which is a direction intersecting the feeding direction. After that, the recording material S on which the toner image is fixed by the fixing device 14 is conveyed by the discharge roller pair 19 in the discharge direction which is the direction intersecting the vertical direction, and is discharged to the discharge tray 20. As described above, in the present embodiment, the configuration in which the transport path shape from the feeding device 13 to the discharge tray 20 is substantially C-shaped in the side view is illustrated, but a transport path having a substantially S-shape in the side view is provided. It may be a configuration.

Further, in the double-sided image forming mode, the sorting member 40 swings in the direction of arrow T2 in FIG. The recording material S passes through the upper part of the sorting member 40, and the rear end portion comes to the position of the sorting member 40 in a state where the front end portion of the recording material S is discharged from the reversing transport port 410 by the rotational drive of the reversing roller pair 41. Will be transported to. After that, the distribution member 40 swings in the direction of arrow T1 in FIG. Then, the reversing roller pair 41 is rotationally driven in the opposite direction, and the recording material S is guided to the double-sided roller pair 42 (42a to 42c). After that, the recording material S is conveyed and guided to the lower side of the image forming apparatus 100 by the rotational drive of the double-sided roller pair 42, and is retransmitted in a state of being inverted with respect to the resist roller pair 17.

After that, as in the case of the single-sided image forming mode, the recording material S is fed to the secondary transfer unit 15 by the resist roller pair 17, and the toner image is transferred. Then, it is introduced into the fixing device 14 again, passes through the lower part of the sorting member 40, and is discharged from the discharge port 190 to the discharge tray 20 by the discharge roller pair 19.

[Operation unit configuration]
Next, the operation unit 50 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 2 is a perspective view of the operation unit 50 according to the present embodiment, FIG. 2 (A) is a perspective view of the operation unit 50 as viewed from the upper surface side, and FIG. 2 (B) is a perspective view of the operation unit (A). It is the figure which turned over 50, and is the perspective view which looked at the operation unit 50 from the lower surface side.

As shown in FIG. 1, the operation unit 50 is arranged on the upper surface of the image forming apparatus 100. Then, the operation unit 50 is attached to the exterior cover member 120 that covers the upper surface of the image forming apparatus 100 at a position substantially above the fixing device 14 in the vertical direction upper side with respect to the position where the fixing device 14 is provided. It is engaged and fixed (Fig. 4). The operation unit 50 is provided on the exterior cover member 120 at a position separated from the discharge tray 20. The exterior cover 120 is an example of the first cover member.

Further, the operation unit 50 has an operation unit cover 511 that engages with the exterior cover member, a display unit 512, and an operation key 513. The operation unit cover 511 is an example of the second cover member. The operation unit cover 511 is provided with a display unit 512 for displaying the function and status of the image forming apparatus 100 to the user, and an operation key 513. By operating the operation key 513, the user or the service person can instruct the image forming operation and input the setting change of the image forming apparatus 100. The operation key 513 is an example of the input means.

As shown in FIG. 2A, the display unit 512 is rotatable in the direction of arrow U with respect to the operation unit cover 511 about a rotation axis (not shown). Further, the display unit 512 can hold the posture at an arbitrary angle by being manually operated by the user. The rotation operation of the display unit 512 may be configured to automatically rotate so as to rise in the direction of the arrow U when the user operates the display unit 512.

The operation key 513 is formed by forming a plurality of holes in the operation unit cover 511 so that the operation key 513 is exposed from the plurality of holes on the upper surface of the image forming apparatus 100, and can be pressed vertically by the user. ing. The user can operate the image forming apparatus 100 via the operation key 513.

In the present embodiment, the operation unit 50 is provided with a display unit 512 and an operation key 513, but other configurations such as an NFC (Near Field Communication) antenna and an IC chip for communicating with a mobile terminal are provided. May be good.

Further, as shown in FIG. 2B, a substrate 514 that is electrically connected to the display unit 512 and the operation key 513 is provided on the lower surface of the operation unit cover 511. The substrate 514 is electrically connected to the CPU of the image forming apparatus 100 by an electric wire (not shown), and can communicate with each other. Further, the board 514 can receive an instruction from the user via the operation key 513 and can control the content to be displayed on the display unit 512. Further, a plurality of switches (not shown) are arranged on the board 514 at positions corresponding to the operation keys 513, and instructions from the operation keys 513 by the user are received via the plurality of switches. The substrate 514 is an example of a control substrate.

The operation unit cover 511 has a wall surface portion 511b whose end portion projects downward with respect to the operation cover upper surface portion 511a, extends downward in the vertical direction, and is continuous in the circumferential direction. The wall surface portion 511b is an example of an extension portion and an example of a second cover wall surface portion. As shown in FIG. 2B, the wall surface portion 511b is formed so as to surround the lower surface portion 511c on the back side of the operation cover upper surface portion 511a. When the operation unit cover 511 is viewed from the back side, the operation unit cover 511 has a substantially box shape having a concave shape.

Further, a plurality of protrusions 516 (516a to 516f) as second engaging portions are provided inside the wall surface portion 511b.

Further, the operation unit cover 511 has a space in the center where the display portion 512 is arranged, and is provided with a fastening hole 518 and a rib-shaped claw engaging portion 517. The protrusion 516, the claw engaging portion 517, and the fastening hole 518 are configured to engage with the exterior cover member 120 and fix the operation unit cover 511 to the exterior cover member 120, which will be described in detail later.

[Structure of exterior cover member]
Next, the exterior cover member 120 of the image forming apparatus 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 3.

FIG. 3 is a perspective view of the exterior cover member 120 according to the present embodiment. 3A is an overall perspective view of the exterior cover member 120, and FIG. 3B is an enlarged view of a portion of the exterior cover member 120 on which the operation unit cover 511 is mounted.

The exterior cover member 120 of the present embodiment is integrally formed with the discharge tray 20, and is a cover that covers the upper surface of the image forming apparatus 100 and is provided so as to prevent foreign matter, dust, and the like from entering the apparatus. Be done.

On the upper surface of the exterior cover member 120 above the image forming apparatus 100 which is substantially directly above the fixing device 14, a wall surface which protrudes upward from the upper surface portion 120a and is continuous in the circumferential direction so as to form a concave substantially box shape. A unit 201 is provided. The wall surface portion 201 is an example of the first cover wall surface portion. The height of the wall surface portion 201 of the exterior cover member 120 in the vertical direction is lower than the height of the wall surface portion 511b of the operation unit cover 511 in the vertical direction. Therefore, when the operation unit cover 511 is engaged with the exterior cover member 120, the upper end portion 201a of the wall surface portion 201 of the exterior cover member 120 comes into contact with the lower surface portion 511c of the operation unit cover 511. The upper end portion 201a is an example of a support portion.

Further, the peripheral length of the wall surface portion 201 of the exterior cover member 120 is shorter than the peripheral length of the wall surface portion 511b of the operation unit cover 511. Therefore, when the operation unit cover 511 engages with the exterior cover member 120, the outside of the wall surface portion 201 of the exterior cover member 120 is covered with the wall surface portion 511b of the operation unit cover 511.

Here, the exhaust port 203 is outside the wall surface portion 201 of the exterior cover member 120 and faces the lower surface portion 511c of the operation unit cover 511 in a state where the exterior cover member 120 and the operation unit cover 511 are engaged with each other. It is provided at the position. As a result, it is possible to prevent the air containing water vapor exhausted from the exhaust port 203 from adhering to the substrate 514 provided on the operation unit cover 511 and condensing.

The wall surface portion 201 has an engaging portion 202 (202a to 202f) having a shape recessed toward the inner wall. Here, the inner wall direction is the direction from the outside to the inside of the wall surface portion 201.

The engaging portion 202 is arranged at a position corresponding to the protrusion 516 (516a to 516f) of the operation unit 50, and is an engaging piece as a first engaging portion that engages with the protrusion 516 (516a to 516f). 222 (222a to 222f) is provided. An exhaust port 203 (203a to 203f) opened at a position corresponding to the engaging portion 202 (202a to 202f) is provided below the engaging portion 202 of the exterior cover member 120 to prevent dew condensation, which will be described later. It is provided in.

Further, the wall surface portion 201 is provided with a low wall portion 211 (211a to 211f) having a height lower than that of the wall surface portion 201 on the outside of the engaging portion 202 (202a to 202f) in the circumferential direction of the wall surface portion 201. .. That is, in the direction intersecting the vertical direction, the discharge port 203 (203a to 203a) is provided between the wall surface portion 201 and the low wall portion 211 (211a to 211f) of the exterior cover member 120. The low wall portions 211 (211a to 211f) are provided to separate the exhaust port 203 from the upper surface portion 120a of the exterior cover member 120, and can prevent foreign matter and the like from falling into the exhaust port from outside the device. can.

The low wall portions 211 (211a to 211f) do not come into contact with the operation unit cover 511 in a state where the exterior cover member 120 and the operation unit cover 511 are engaged with each other. Therefore, a gap is formed between the low wall portion 211 (211a to 211f) and the wall surface portion 511b of the operation unit cover 511 in a state where the exterior cover member 120 and the operation unit cover 511 are engaged with each other. As a result, the air in the image forming apparatus 100 containing the water vapor generated from the fixing apparatus 14 is discharged to the outside of the apparatus from the exhaust ports 203 (203a to 203f). In the state where the exterior cover member 120 and the operation unit cover 511 are engaged, the wall surface portion 201 of the exterior cover member 120 is in contact with the lower surface portion 511c of the operation unit cover 511 to support the operation unit cover 511. Therefore, the air exhausted from the exhaust port 203 is exhausted to the outside of the device without flowing into the inside of the wall surface portion 201.

In the present embodiment, the discharge port 203 is provided between the wall surface portion 201 and the low wall portion 211 of the exterior cover member 120 in the direction intersecting the vertical direction. That is, the discharge port 203 is provided outside the wall surface portion 201 and inside the low wall portion 211 in the circumferential direction. Then, the low wall portion 211 is in a state where the exterior cover member 120 and the operation unit cover 511 are engaged with each other in the direction intersecting the vertical direction with the wall surface portion 201 of the exterior cover member 120 and the wall surface portion 511b of the operation unit cover 511. It is provided between. That is, the low wall portion 211 is provided outside the discharge port 203 in the circumferential direction and inside the wall surface portion 511b of the operation unit cover 511. Therefore, as compared with the case where the exhaust port is directly provided on the upper part of the main body of the device or the case where the low wall portion is not provided, it is possible to further prevent foreign matter and the like from falling into the exhaust port from outside the device.

Further, inside the wall surface portion 201, a claw portion 204, a fastening hole 205, an electric wire opening 206, and a partition wall 207 are provided. The claw portion 204 engages with the claw engaging portion 517 of the operation unit cover 511. The fastening hole 205 is coaxial with the fastening hole 518 of the operation unit cover 511, and the operation unit 50 and the exterior cover member 20 can be firmly fixed by fastening with screws. The electric wire opening 206 is an opening through which an electrical connection line (not shown) for electrically connecting the substrate 514 of the operation unit 50 and the CPU of the image forming apparatus 100 is inserted. The upper surface of the partition wall 207 comes into contact with the lower surface portion 511c of the operation unit cover 511, and the water vapor flowing in from the electric wire opening 206 adheres to the substrate 514 of the operation unit 50 and condenses to prevent malfunction. .. Further, the partition wall 207 is an example of the partition wall portion.

[Fixing the operation unit]
A method of fixing the operation unit 50 to the exterior cover member 120 according to the embodiment of the present invention will be described with reference to FIGS. 2 to 5.

FIG. 4 is a perspective view showing a method of fixing the operation unit 50 according to the present embodiment. FIG. 4A shows a state before the operation unit 50 is fixed, and FIG. 4B shows a state in which the operation unit 50 is fixed to the exterior cover member 120.

FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4B showing a method of fixing the operation unit 50 according to the present embodiment. FIG. 5A shows a state in which the operation unit 50 is moved in the direction of arrow V1, and FIG. 5B shows a state in which the operation unit 50 is moved in the direction of arrow V2. The arrow V1 direction and the arrow V2 direction are examples of predetermined directions.

When fixing the operation unit 50 to the exterior cover member 120, first, the operation unit 50 is lowered perpendicularly to the exterior cover member 120 in the direction of arrow V1 from above the exterior cover member 120. At this time, the positions of the protrusions 516 (516a to 516) of the operation unit cover 511 and the positions of the engaging portions 202 (202a to f) of the exterior cover member 20 are aligned. Here, the protrusion 516 is moved in the direction of the arrow V1 toward the exhaust port 203 that is open below the engaging portion 202. When the operation unit 50 is lowered in the direction of the arrow V1, the upper end portion 201a of the wall surface portion 201 of the exterior cover member 120 and the lower surface portion 511c of the operation unit cover 511 come into contact with each other. Further, the upper end portion of the partition wall 207 and the lower surface portion 511c of the operation unit cover 511 come into contact with each other.

Next, the operation unit 50 is horizontally moved in the arrow V2 direction from the front side to the back side of the image forming apparatus 100, and the claw engaging portion 517 of the operation unit cover 511 and the claw portion 204 of the exterior cover member 20 are moved. Engage and temporarily fix. At this time, as the operation unit cover 511 moves in the arrow V2 direction, the protrusions 516 (516a to 516a to f) and the engaging parts 202 (202a to 202a) engage with each other. Specifically, as the arrow V2 moves, the protrusion 516 (516a to f) abuts on the wall surface of the engagement portion 202 (202a to f) and engages with the engagement piece 222 (222a to f). Vertical movement is restricted.

The engaging pieces 222 (222a to 222a) come into contact with the lower surface portion 511c of the operation unit cover 511 in a state of being engaged with the protrusions 516 (516a to 516a to f). The engaging piece 222 is an example of the first engaging portion and is an example of the supporting portion. As described above, the length of the wall surface portion 511b of the operation unit cover 511 in the vertical direction is smaller than the length of the wall surface portion 201 of the exterior cover member 120 in the vertical direction.

That is, the wall surface portion 511b of the operation unit cover 511 does not come into contact with the upper surface portion 120a of the exterior cover member 120. Further, the height of the low wall portion 211 is lower than that of the wall surface portion 201 of the exterior cover member 120.

As a result, a gap is formed between the exhaust port 203 (203a to 203a) and the wall surface portion 511b of the exterior cover 511. Therefore, with the protrusions 516 (516a to 516) of the operation unit cover 511 and the engaging pieces 222 (222a to f) of the exterior cover member 120 engaged, the protrusions 516 (516a to f) are at the exhaust port 203 ( The configuration is such that the exhaust from the exhaust port 203 (203a to 203a) is not obstructed without blocking the 203a to 203a). The configuration of the exhaust gas from the exhaust port 203 will be described later with reference to FIG. 7. The operation unit cover 511 of the operation unit 50 is positioned with respect to the exterior cover member 120 by the engagement between the claw engaging portion 517 and the claw portion 204 and the engagement between the protrusion 516 and the engaging portion 202.

[Condensation measures]
The dew condensation countermeasures according to the embodiment of the present invention will be described with reference to FIGS. 6 and 7.

FIG. 6 is a perspective view of the vicinity of the discharge double-sided transport portion according to the embodiment of the present invention, and FIG. 7 is a cross-sectional view of the vicinity of the discharge double-sided transport portion.

As shown in FIG. 1, the discharge double-sided transport unit is located substantially above the fixing device 14.

The discharge transport path W1 is a path for discharging the recording material S from the discharge port 190 to the discharge tray 20, and is composed of an upper surface of the first guide member 45a and a lower surface of the second guide member 45b facing the upper surface. When the swingable distribution member 40 is in the T1 direction in the drawing, the recording material S conveyed from the fixing device 14 passes through the lower surface of the distribution member 40 and is guided to the discharge transfer path W1.

The double-sided transfer path W2 is a path for guiding the recording material S on which an image is formed on one surface to the reversing roller pair 41 that conveys the recording material S to the determination transfer port 410, and is a path that guides the upper surface of the second guide member 45b and the third facing the upper surface of the second guide member 45b. It is composed of the lower surface of the guide member 45c. When the distribution member 40 is in the T2 direction in the drawing, the recording material S conveyed from the fixing device 14 passes through the upper surface of the distribution member 40 and is guided to the double-sided transfer path W2.

The discharge double-sided transport unit is provided with a first intake fan 43a for sucking outside air from the outside of the image forming apparatus 100 and keeping the inside of the apparatus at a positive pressure with respect to the outside of the apparatus. The air flowing out of the first intake fan 43a is guided by the duct 44 in the direction of arrow X1. The air flowing out of the first intake fan 43a is also used to dry the first guide member 45a, the second guide member 45b, the third guide seat 45c, etc. through the duct 44.

As shown in FIG. 1, a second intake fan 43b for sucking outside air from outside the device is provided on the upper left of the image forming apparatus 100. The air flowing out from the second intake fan 43b is blown onto the cartridge 7 as shown in X2 in the figure to promote cooling. Further, the second intake fan 43b has a function of keeping the inside of the device at a positive pressure with respect to the outside of the device. In particular, the space between the fixing device 14 to which the recording material S on which the image is fixed by the fixing device 14 is conveyed to the discharge port 190 and the reverse transfer port 410 acts as a positive pressure. Here, the positive pressure refers to a state in which the pressure inside the image forming apparatus 100 is higher than that outside the apparatus.

As described above, the recording material S on which the image is formed in the image forming apparatus 100 evaporates the water content contained in the recording material S when the fixing device 14 heats and pressurizes the recording material S. Along with this, air containing a large amount of water vapor may be discharged from the fixing device 14.

In this way, the air containing water vapor is discharged from the discharge port 190 and the reverse transfer port 410 to the outside of the device as the sheet is discharged by the discharge roller pair 19 and the sheet is moved by the reverse roller pair 41. It is exhausted.

However, when the amount of water vapor generated from the fixing device 14 is large, the exhaust from the discharge port 190 or the reversing transport port 410 is not sufficient, and the water vapor adheres to the transport guide or the like, which may cause dew condensation inside the device. There is sex. Therefore, in the present embodiment, the exterior cover member 120 is provided with the exhaust ports 203 (203a to 203a) separately from the sheet discharge port 190 and the reverse transfer port 410.

The air containing water vapor generated by the recording material S passing through the fixing device 14 is warmer than the air in the device, and flows above the fixing device 14 due to the temperature difference. Therefore, the air that is not exhausted from the discharge port 190 and the reverse transport port 410 flows to the upper side of the fixing device 14 through the gaps between the upper members such as the second guide member 45b, the third guide member 45c, and the transport path. To go.

Then, the air flowing above the fixing device 14 is taken in from the first intake fan 43a, passes through the duct 44, flows from the vent 46 in the direction of arrow X3, and further to the exterior cover member 120 above the device. It flows toward. As described above, the exterior cover member 120 is provided with exhaust ports 203 (203a to 203f). Therefore, the air flowing in the direction of arrow X3 and flowing above the device passes through the exhaust port 203 of the exterior cover member 120 as shown in the direction of arrow X4 in FIG. 7, and passes through the gap between the exterior cover member 120 and the operation unit cover 511. It is exhausted to the outside of the device. More specifically, the air in the image forming apparatus 100 containing water vapor is exhausted from the gap between the low wall portion 211 of the exterior cover 120 and the wall surface portion 511b of the operation unit cover 511.

In the present embodiment, as described above, the inside of the image forming apparatus 100 is maintained at a positive pressure by the first intake fan 43a and the second intake fan 43b. Therefore, the air containing a large amount of water vapor is easily exhausted to the outside of the device of the image forming apparatus 100 through the exhaust port 203 of the seat and the exhaust port 203 communicating with the outside of the device. That is, the air containing water vapor generated from the fixing device 14 does not stay in the exhaust double-sided transport section or the like located above the fixing device 14, but flows to the discharge port 190, the reverse transport port 410, or the exhaust port 203.

Further, in the present embodiment, as shown in FIG. 4, the exhaust port 203 is provided at a position hidden by the wall surface portion 511b of the operation unit cover 511 on the exterior cover 120. That is, it is provided at a position that is difficult to see in the image forming apparatus 100. As a result, even when the fixing device 14 is provided above the image forming apparatus 100 and the exhaust port 203 is provided on the upper surface of the apparatus main body of the image forming apparatus 100, the appearance quality of the image forming apparatus 100 is not impaired. The air inside the device can be sufficiently exhausted. Therefore, it is possible to provide an image forming apparatus 100 capable of preventing stains due to adhesion of water droplets to the recording material due to dew condensation inside the apparatus.

Further, if the exhaust port 203 is exposed on the upper surface of the exterior cover 120, foreign matter or the like may fall from the exhaust port 203 into the image forming apparatus 100. However, in the present embodiment, the exhaust port 203 is not exposed on the upper surface of the exterior cover 120, and the upper part of the exhaust port 203 is covered with a part of the operation unit cover 511. Therefore, it is possible to prevent foreign matter from falling into the device from the exhaust port 203. Further, since the low wall portion 211 is provided between the exhaust port 203 and the upper surface portion 120a of the exterior cover 120, foreign matter or the like falls from the gap between the exterior cover 120 and the operation unit cover 511 to the discharge port 203. It can be prevented from being stored.

[Other Embodiments]
In the present embodiment, the operation unit 50 is fixed by moving the image forming apparatus 100 horizontally from the front side to the back side, but the moving direction may be reversed from the back side to the front side. Further, the moving direction may be changed by 90 degrees from the left side to the right side or from the right side to the left side.

Further, in the present embodiment, after the operation unit 50 is temporarily fixed by engaging the claw portion 517 and the claw portion 204 of the exterior cover member 20, the fastening hole 518 of the operation unit 50 and the exterior cover member 120 are fastened. The hole 205 is fixed with a screw, but the configuration is not limited to this. For example, by increasing the engaging force between the claw engaging portion 517 and the claw portion 204, fixing of the exterior cover member 120 with screws may be omitted.

Further, the operation unit 50 is vertically lowered and then moved horizontally so that the protrusion 516 of the operation unit 50 is inserted into the engaging portion 202 of the exterior cover member 120, but the configuration is not limited to this. good. For example, the protrusion 516 may be elastically deformed so as to be able to escape from the engaging portion 202, so that the horizontal movement of the operation unit 50 may be omitted and the operation unit 50 may be fixed only by the vertical movement. Further, the shapes of the protrusion 516 and the engaging portion 202 are not limited to the above-described configurations, and the concave and convex portions have a shape as long as the shape does not hinder the function of discharging air from the exhaust port 203 in the engaged state. It may have such a shape.

In order to take in outside air from the outside of the image forming apparatus 100 and keep the inside of the apparatus at a positive pressure with respect to the outside of the apparatus, an intake fan 43a is arranged in the discharge double-sided transport portion, and an intake fan 43b is arranged in the vicinity of the cartridge 7. However, the arrangement and number of fans are not limited to this. Other configurations may be used as long as the inside of the device is maintained at a positive pressure with respect to the outside of the device. For example, if the configuration is such that the outside air is taken in from the outside of the device, a fan for cooling the drive motor that operates the supply device 13 may be arranged. Further, in the present embodiment, the air taken in by the intake fan 43b is discharged in the X2 direction, but the intake air is used for cooling the fixing device 14 and the recording material S through above the intermediate transfer belt 5. There may be.

Further, although the exterior cover member 120 is integrated with the discharge tray and covers the entire upper surface of the image forming apparatus 100, the discharge tray may be a separate body. Further, the configuration may be such that it is substantially directly above the fixing device 14 and covers only the lower side of the operation unit 50.

Further, although the configuration in which the display unit 512 and the operation keys 513 are provided on the operation unit cover 511 is shown, the operation keys 513 may be omitted by providing the touch panel that also serves as the display unit and the operation unit. In this case, the user inputs a job of the image forming apparatus, inputs a setting change, and the like via the touch panel. Even in this case, it is preferable to provide a partition wall between the control board and the wire opening so that water vapor does not adhere to the control board that controls the touch panel and dew condensation does not occur.

100 Image forming device 120 Exterior cover member 14 Fixing device 19 Discharge roller vs. 190 Discharge port 20 Discharge tray 201 Wall surface 202 (202a to 202f) Engagement part 203 (203a to 203f) Exhaust port 204 Claw part 205 Fastening hole 206 Wire opening Part 207 Partition part 222 (222a to 222f) Engagement piece 40 Sorting member 41 Reversing roller pair 410 Reversing transport port 43a First intake fan 43b Second intake fan 44 Duct 50 Operation unit 511 Operation unit cover 511a Top surface part 511b Wall surface Part 511c Bottom part 512 Display part 513 Operation key 514 Board 516 (516a to 516f) Protrusion part 517 Claw engagement part 518 Fastening hole

Claims (8)

An image forming apparatus having an image forming means for forming an image on a recording material.
Heating the record material on which the image is formed by the image forming unit, a fixing unit configured to fix an image on a recording material,
A discharge port for discharging the recording material on which the image is fixed by the fixing means, and
A first cover member that covers at least the upper part of the fixing means and constitutes the upper surface of the image forming apparatus.
A second cover member having a second engaging portion that engages with the first engaging portion of the first cover member and provided with an input means for receiving an input from a user.
The first cover member includes a support portion that supports the second cover member in a state where the second engaging portion and the first engaging portion are engaged, the fixing means, and the exhaust port. It has an exhaust port that communicates with the space between the device and exhausts the air in the space to the outside of the device.
Said second cover member is extended beauty below the vertical direction, a height in the vertical direction has a low had extended portion from the support portion,
The exhaust port is provided between the support portion and the extension portion in a direction intersecting the vertical direction in a state where the first engaging portion and the second engaging portion are engaged. An image forming apparatus characterized by. The second engaging portion abuts against the first engaging portion by moving the second cover member in a predetermined direction with respect to the first cover member, and the second engaging portion is subjected to the second engaging portion. The first aspect of the invention is characterized in that the second cover member engages with the first engaging portion in a state where the second cover member is restricted from moving in the vertical direction when the first engaging portion is abutted against the first engaging portion. The image forming apparatus according to. The first cover member has a plurality of exhaust ports different from the exhaust port, and a plurality of engaging pieces different from the first engaging portion at positions corresponding to the plurality of exhaust ports.
The second cover member has a plurality of protrusions that engage with the plurality of engaging pieces, unlike the second engaging portion.
The image forming apparatus according to claim 2. The second cover member is provided with the extending portion continuously in the circumferential direction so that the surface of the second cover member facing the first cover member has a concave shape, and the second cover wall surface portion. The first cover member has a first cover wall surface portion in which the support portion is continuously provided in the circumferential direction and the peripheral length is smaller than that of the second cover wall surface portion.
The length of the second cover wall surface portion in the vertical direction is smaller than the length of the first cover wall surface portion in the vertical direction.
The image forming apparatus according to any one of claims 1 to 3, wherein the exhaust port is provided on the outside of the first cover wall surface portion. The second cover member has a control substrate that controls the input means inside the second cover wall surface portion and between the first cover member and the second cover member.
The first cover member has an opening through which a connection line for electrically connecting the control substrate and another substrate provided in the image forming apparatus is inserted inside the first cover wall surface portion, and the control. The image forming apparatus according to claim 4, further comprising a partition wall portion provided so as to separate the substrate from the opening. An intake fan for sucking air from the outside of the image forming apparatus into the apparatus is further provided.
The image forming apparatus according to any one of claims 1 to 5, wherein the exhaust port exhausts air taken in by the intake fan. The image forming apparatus according to any one of claims 1 to 6, wherein the first cover member has a loading portion for loading a recording material discharged from the discharge port. The image forming apparatus according to claim 7, wherein the second cover member is arranged at a position adjacent to the loading portion of the first cover member.

Images