Sheet conveyance device, image forming device and image reading device

Abstract

To properly clean a rotating body that conveys a sheet while suppressing an increase in size of a sheet conveyance device.SOLUTION: A sheet conveyance device includes: a rotating body that conveys a sheet by rotating in contact with the sheet; and a cleaning part that cleans the rotating body. The cleaning part includes: a cleaning member that contacts an outer peripheral surface of the rotating body to remove a foreign matter from the outer peripheral surface of the rotating body; and a housing that stores the foreign matter removed from the outer peripheral surface of the rotating body, wherein a part of the housing is arranged in a position capable of coming into contact with the sheet, and guides the sheet conveyed by the rotating body.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sheet conveying device, an image forming apparatus, and an image reading apparatus. [Background technology]

[0002] A conventional sheet conveying device includes a rotating body that rotates in contact with a sheet to convey the sheet. Such a sheet conveying device is disclosed, for example, in Patent Document 1. In Patent Document 1, a roller is used as the rotating body that conveys the sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-269709 Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which a sheet is conveyed by contacting a rotating body with the sheet, if the rotating body is not properly cleaned, the rotating body may slip relative to the sheet, resulting in conveyance problems. To prevent this problem, a cleaning unit that cleans the rotating body can be installed. However, installing a cleaning unit requires securing installation space for the cleaning unit, which increases the size of the sheet conveying device.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a sheet conveying device, an image forming device, and an image reading device that are capable of properly cleaning the rotating body that transports the sheet while preventing the sheet conveying device from becoming larger. [Means for solving the problem]

[0006] To achieve the above object, a sheet conveying device according to a first aspect of the present invention includes a rotating body that conveys a sheet by rotating in contact with the sheet, and a cleaning unit that cleans the rotating body. The cleaning unit includes a cleaning member that contacts the outer peripheral surface of the rotating body to remove foreign matter from the outer peripheral surface of the rotating body, and a housing that stores the foreign matter removed from the outer peripheral surface of the rotating body. A part of the housing is positioned so as to be able to contact the sheet, and guides the sheet conveyed by the rotating body.

[0007] An image forming apparatus according to a second aspect of the present invention includes the sheet conveying device described above and a printing section that prints on the sheet conveyed by the sheet conveying device.

[0008] An image reading device according to a third aspect of the present invention includes the sheet conveying device described above, and an image reading section that reads an image formed on a sheet conveyed by the sheet conveying device. [Effects of the Invention]

[0009] The configuration of the present invention can appropriately clean the rotating body that transports the sheet while suppressing an increase in size of the sheet transport device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic diagram illustrating the internal configuration of the multifunction peripheral according to the embodiment. [Figure 2] FIG. 2 is a schematic diagram of a paper feeding device according to an embodiment. [Figure 3] FIG. 2 is a schematic diagram illustrating an internal configuration of a document transport device according to an embodiment. [Figure 4] 2 is a schematic diagram of a document feed belt cleaning unit and its periphery that is installed in the document transport device according to the embodiment; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described below using a multifunction peripheral as an example. <Overall configuration of the multifunction device> The multifunction device 100 of this embodiment has a configuration as shown in FIG. 1. The multifunction device 100 corresponds to an "image forming device" and an "image reading device." The multifunction device 100 includes a paper feeder 1 and a document transporter 2 as sheet transport devices. The paper feeder 1 transports paper P as a sheet. The document transporter 2 transports a document D as a sheet. The configurations of the paper feeder 1 and the document transporter 2 will be described in detail later.

[0012] In the following description, the direction perpendicular to the conveyance direction of sheets (paper P and document D) in multifunction device 100 is referred to as the width direction. The direction perpendicular to the paper surface of Fig. 1 is the width direction. For example, the front-to-rear direction of multifunction device 100 corresponds to the width direction.

[0013] The multifunction device 100 includes a printing unit 10. The printing unit 10 includes a paper transport path PP (in FIG. 1, the paper transport path PP is indicated by a dashed arrow). The printing unit 10 supplies paper P to the paper transport path PP and transports the paper P along the paper transport path PP. The paper feeder 1 supplies the paper P to the paper transport path PP. The printing unit 10 executes a print job. In other words, the printing unit 10 prints an image on the paper P being transported along the paper transport path PP.

[0014] Although not shown, the printing unit 10 includes one or more paper transport roller pairs. Each paper transport roller pair has a pair of rollers that are pressed against each other. The paper transport roller pair has a paper transport nip between the pair of rollers. The paper transport roller pair rotates to transport paper P that has entered the paper transport nip. In other words, the paper transport roller pair nip the paper P between the pair of rollers and transports the paper P by rotating in that state. The paper transport roller pair is arranged on the paper transport path PP and transports the paper P along the paper transport path PP.

[0015] The printing unit 10 includes an image forming unit 3. The image forming unit 3 includes a photosensitive drum 31 and a transfer roller 32. The photosensitive drum 31 carries a toner image on its peripheral surface. The transfer roller 32 is pressed against the photosensitive drum 31, forming a transfer nip between the photosensitive drum 31 and the transfer roller 32. The transfer roller 32 rotates together with the photosensitive drum 31. The image forming unit 3 transfers the toner image onto the paper P while transporting the paper P that has entered the transfer nip. This causes an image to be printed on the paper P.

[0016] Although not shown, the image forming unit 3 includes a charging device, an exposure device, and a developing device. The charging device charges the circumferential surface of the photosensitive drum 31. The exposure device forms an electrostatic latent image on the circumferential surface of the photosensitive drum 31. The developing device develops the electrostatic latent image on the circumferential surface of the photosensitive drum 31 into a toner image.

[0017] The printing unit 10 includes a fixing unit 4. The fixing unit 4 includes a heating roller 41 and a pressure roller 42. The heating roller 41 has a built-in heater. The pressure roller 42 presses against the heating roller 41, forming a fixing nip between the heating roller 41 and the pressure roller 42. The pressure roller 42 rotates together with the heating roller 41. The fixing unit 4 fixes the toner image transferred onto the paper P to the paper P while transporting the paper P that has entered the fixing nip. The paper P that has exited the fixing nip is discharged onto the discharge tray T1.

[0018] The multifunction device 100 also includes an image reading unit 20. The image reading unit 20 reads an image formed on an original document D and generates image data of the read original document D. In a copy job, which is a print job that involves reading the original document D, the printing unit 10 prints an image onto paper P based on the image data of the original document D obtained by reading the original document D. In a scan job, the image data of the original document D obtained by reading the original document D is sent to and saved in an external device. Examples of external devices include a personal computer that is communicably connected to the multifunction device 100, and an external memory (for example, a USB memory) that is attached to the multifunction device 100.

[0019] The image reading unit 20 includes a contact glass C1 on which an original D is placed. The original D is placed on the contact glass C1 by a user. The image reading unit 20 also includes a contact glass C2. The original D is automatically transported onto the contact glass C2 by the document transport device 2.

[0020] The image reading unit 20 includes optical components such as a light source 201, an image sensor 202, and a mirror (reference numerals omitted). The light source 201 irradiates light onto the original D. The light reflected from the original D is reflected by the mirror and guided to the image sensor 202. The image sensor 202 receives the light reflected from the original D. The image reading unit 20 generates image data of the original D to be used in copy jobs, scan jobs, etc. by A / D converting the output value of the image sensor 202 that has received the light reflected from the original D.

[0021] The image reading unit 20 has a reading mode for reading the original D, a placed reading mode, and a conveyed reading mode. In the placed reading mode, the user places the original D on the contact glass C1, light is irradiated onto the original D on the contact glass C1, and image data of the original D is generated based on the reflected light. On the other hand, in the conveyed reading mode, the original D is conveyed onto the contact glass C2 by the original conveying device 2, light is irradiated onto the original D passing over the contact glass C2, and image data of the original D is generated based on the reflected light.

[0022] 1, the paths of light emitted from the light source 201 and the light reflected by the document D are shown by dashed two-dot lines. As an example, FIG. 1 shows the path of light reflected by the document D on the contact glass C2.

[0023] <Configuration of the paper feeder> The paper feeding device 1 has a configuration as shown in FIG. 2. The paper feeding device 1 has a part of a paper transport path PP. The paper transport path PP of the paper feeding device 1 is connected to the paper transport path PP of the main body of the multifunction device 100. The paper feeding device 1 supplies paper P to the paper transport path PP and transports the paper P along the paper transport path PP. In this way, the paper P is supplied to the main body of the multifunction device 100 (i.e., the printing unit 10).

[0024] The paper feeding device 1 includes a paper cassette CA. The paper cassette CA is detachable from the main body of the multifunction device 100. Paper P is set in the paper cassette CA. As a print job is executed, the paper P in the paper cassette CA is consumed and reduced. When the paper P runs out in the paper cassette CA due to the execution of the print job, the paper cassette CA is removed from the main body of the multifunction device 100, and paper P is set in the paper cassette CA. Then, after the paper P is set, the paper cassette CA is re-installed in the main body of the multifunction device 100.

[0025] A paper lift plate L1 is disposed in the paper cassette CA. By setting paper P in the paper cassette CA, the paper P is placed on the paper lift plate L1. The paper lift plate L1 can be displaced so that the downstream end in the paper transport direction swings up and down, with the upstream end of the paper transport direction as a fulcrum. In other words, the paper lift plate L1 can be raised and lowered. In the following description, raising the paper lift plate L1 means that the downstream end of the paper transport direction of the paper lift plate L1 is displaced upward.

[0026] The paper feeding device 1 includes a paper pickup roller 11. The paper pickup roller 11 is supported rotatably around an axis extending in the width direction. The paper pickup roller 11 is connected to a motor (not shown) and rotates by receiving driving force from the motor. The paper pickup roller 11 is disposed facing the paper lift plate L1 in the vertical direction. When paper P is set in the paper cassette CA, the paper P on the paper lift plate L1 and the paper pickup roller 11 face each other in the vertical direction. The paper pickup roller 11 rotates while contacting the topmost paper P on the paper lift plate L1 from above. The paper pickup roller 11 rotates while contacting the paper P on the paper lift plate L1, thereby transporting the paper P on the paper lift plate L1. This causes the paper P to be pulled out of the paper cassette CA.

[0027] During the execution of a print job, the paper lift plate L1 repeatedly rises and stops rising. The paper lift plate L1 rises until it comes into contact with the topmost sheet P on the paper lift plate L1, and stops rising when the contact pressure with the topmost sheet P on the paper lift plate L1 reaches a target value. This maintains contact between the paper P in the paper cassette CA and the paper pickup roller 11 even if the number of sheets P in the paper cassette CA decreases.

[0028] The paper feeding device 1 includes a paper feed roller 12 and a paper separation roller 13. The paper feed roller 12 and the paper separation roller 13 are disposed downstream in the paper transport direction from the paper pickup roller 11. The paper feed roller 12 and the paper separation roller 13 are each supported rotatably around an axis extending in the width direction.

[0029] Paper feed roller 12 rotates by receiving a driving force from a motor (not shown) (for example, the same motor as the motor connected to paper pickup roller 11). Paper separation roller 13 presses against paper feed roller 12, forming a paper feed nip between itself and paper feed roller 12. When paper P is pulled out from paper lift plate L1, the paper P enters the paper feed nip. Paper feed roller 12 and paper separation roller 13 rotate in contact with paper P that has entered the paper feed nip, thereby transporting the paper P that has entered the paper feed nip.

[0030] The paper separation roller 13 is connected to a torque limiter (not shown). The torque limiter is disposed on the rotational shaft of the paper separation roller 13. The torque limiter disables the rotational shaft of the paper separation roller 13 from rotating if the rotational drive force transmitted from the paper feed roller 12 to the paper separation roller 13 is below a threshold value. When the preceding paper P and the next paper P overlap and enter the paper feed nip, the paper feed roller 12 contacts the preceding paper P and moves it forward, but the paper separation roller 13 does not contact the preceding paper P but contacts the next paper P. This makes it difficult for the rotational drive force to be transmitted from the paper feed roller 12 to the paper separation roller 13. As a result, the rotational drive force transmitted from the paper feed roller 12 to the paper separation roller 13 becomes below the threshold value, and the paper separation roller 13 does not rotate.

[0031] In this way, while paper feed roller 12 rotates, paper separation roller 13 does not rotate, so that the progress of the next paper sheet P, which does not come into contact with paper feed roller 12 but comes into contact with paper separation roller 13, is suppressed. This separates the preceding paper sheet P from the next paper sheet P. In other words, this eliminates the problem of multiple sheets of paper P being fed overlapping each other.

[0032] <Configuration of the paper pickup roller cleaning unit> The paper feeding device 1 is equipped with a paper pickup roller cleaning unit 14 (see FIG. 2). The paper pickup roller cleaning unit 14 cleans the paper pickup roller 11. In this configuration, the paper pickup roller cleaning unit 14 corresponds to the "cleaning unit," and the paper pickup roller 11 corresponds to the "rotating body."

[0033] Paper pickup roller cleaning unit 14 removes foreign matter from the outer peripheral surface of paper pickup roller 11. When paper P comes into contact with the outer peripheral surface of paper pickup roller 11, paper dust adheres to the outer peripheral surface. When paper pickup roller cleaning unit 14 cleans paper pickup roller 11, at least paper dust is removed as foreign matter from the outer peripheral surface of paper pickup roller 11.

[0034] The paper pickup roller cleaning unit 14 includes a housing 140, a brush roller 141, and a scraper 142. The brush roller 141 corresponds to the "cleaning member."

[0035] The housing 140 has a storage area. Specifically, the housing 140 is box-shaped and has walls that surround a space that serves as the storage area. However, the box-shaped member that serves as the housing 140 has an opening 140a that connects the internal area (i.e., the storage area) of the housing 140 with the external area. The housing 140 stores the foreign matter removed from the paper pickup roller 11 in the storage area.

[0036] The housing 140 is detachable from the main body of the multifunction device 100 (in other words, the paper feeding device 1). By removing the housing 140 from the main body of the multifunction device 100, it is possible to dispose of foreign matter accumulated in the housing 140. After the disposal operation, the housing 140 is reattached to the main body of the multifunction device 100.

[0037] Brush roller 141 is rotatably attached to housing 140. Brush roller 141 has a rotation shaft and a plurality of raised bristles standing up from the outer circumferential surface of the rotation shaft. Brush roller 141 brings the raised bristles into contact with the outer circumferential surface of paper pickup roller 11.

[0038] Scraper 142 is attached to housing 140. Scraper 142 contacts the outer peripheral surface of brush roller 141. Brush roller 141 rotates with scraper 142 in contact with its outer peripheral surface. Scraper 142 charges brush roller 141 by contacting the outer peripheral surface of brush roller 141. Brush roller 141 electrically attracts foreign matter adhering to the outer peripheral surface of paper pickup roller 11, thereby removing the foreign matter from the outer peripheral surface of paper pickup roller 11. Scraper 142 also removes the foreign matter from the outer peripheral surface of brush roller 141 by contacting the outer peripheral surface of brush roller 141. The foreign matter removed from the outer peripheral surface of brush roller 141 falls and is stored in a storage area of ​​housing 140.

[0039] Brush roller 141 is disposed in the storage area of ​​housing 140, with a portion of it exposed to the outside of the storage area through opening 140a of housing 140. The portion of brush roller 141 exposed through opening 140a of housing 140 comes into contact with paper pickup roller 11.

[0040] Scraper 142 is entirely disposed in the storage area of ​​housing 140. One end of scraper 142 contacts the outer peripheral surface of brush roller 141, and the other end is attached to housing 140. As a result, foreign matter removed from the outer peripheral surface of brush roller 141 by scraper 142 is stored in the storage area of ​​housing 140.

[0041] In a configuration in which brush roller 141 and scraper 142 are attached to housing 140, simply by removing housing 140 from the main body of multifunction device 100 (i.e., paper feeding device 1), brush roller 141 and scraper 142 can also be removed from the main body of multifunction device 100. This is convenient because maintenance of brush roller 141 and scraper 142 (for example, checking the degree of wear) can be performed at the same time as discarding accumulated matter (foreign matter) accumulated in housing 140.

[0042] Here, the housing 140 has a part of its wall as a guide portion 1401. The guide portion 1401 is a portion that guides the paper P that is transported by the paper pickup roller 11.

[0043] Specifically, the paper pickup roller cleaning unit 14 is positioned upstream of the paper pickup roller 11 in the paper transport direction and above the paper lift plate L1. This causes a portion of the wall of the housing 140 to face the paper lift plate L1 in the vertical direction. When paper P is placed on the paper lift plate L1, a portion of the wall of the housing 140 faces the paper P on the paper lift plate L1 in the vertical direction. The portion of the wall of the housing 140 that faces the paper P on the paper lift plate L1 in the vertical direction is the guide portion 1401.

[0044] As a result, when the paper pickup roller 11 transports the paper P on the paper lift plate L1, even if the paper P on the paper lift plate L1 floats up, the top surface of the paper P contacts the guide portion 1401. As a result, the paper pickup roller 11 can transport the paper P on the paper lift plate L1 smoothly. In other words, the guide portion 1401 (i.e., a part of the housing 140) guides the paper P on the paper lift plate L1 transported by the paper pickup roller 11. In yet another way, the housing 140 has a guide surface, and guides the paper P on the paper lift plate L1 by bringing the top surface of the paper P on the paper lift plate L1 transported by the paper pickup roller 11 into contact with the guide surface.

[0045] In this embodiment, as described above, a part of housing 140 (specifically, guide portion 1401) is positioned so as to be able to come into contact with paper P. This part of housing 140 guides paper P transported by paper pickup roller 11. This eliminates the need to provide a separate member for guiding paper P near the area where housing 140 is located, thereby preventing paper feeding device 1 from becoming larger. In other words, paper pickup roller 11 can be properly cleaned while preventing paper feeding device 1 from becoming larger.

[0046] By properly cleaning the paper pickup roller 11, it is possible to effectively remove foreign matter such as paper dust adhering to the paper pickup roller 11. As a result, it is possible to prevent problems such as the paper pickup roller 11 slipping on the paper P. In other words, it is possible to prevent problems with the transport of the paper P.

[0047] For example, the area around paper pickup roller 11 is covered with an openable cover to improve the efficiency of jam clearance. Opening the cover exposes the area around paper pickup roller 11. This configuration is convenient because the housing 140 can be attached or detached by opening the cover around paper pickup roller 11 (i.e., the cover for jam clearance).

[0048] Furthermore, in this embodiment, foreign matter adhering to brush roller 141 is removed by scraper 142. This prevents brush roller 141 from insufficiently cleaning paper pickup roller 11. Foreign matter removed from brush roller 141 is collected in housing 140, preventing foreign matter from scattering around paper pickup roller 11.

[0049] <Configuration of the paper separation roller cleaning unit> The paper feeding device 1 is equipped with a paper separation roller cleaning unit 15 (see FIG. 2). The paper separation roller cleaning unit 15 cleans the paper separation roller 13. In this configuration, the paper separation roller cleaning unit 15 corresponds to the "cleaning unit," and the paper separation roller 13 corresponds to the "rotating body."

[0050] Paper separation roller cleaning unit 15 removes foreign matter from the outer peripheral surface of paper separation roller 13. When paper P comes into contact with the outer peripheral surface of paper separation roller 13, paper dust adheres to the outer peripheral surface. When paper separation roller cleaning unit 15 cleans paper separation roller 13, at least paper dust is removed as foreign matter from the outer peripheral surface of paper separation roller 13.

[0051] The paper separation roller cleaning unit 15 includes a housing 150, a brush roller 151, and a scraper 152. The brush roller 151 corresponds to the "cleaning member."

[0052] The housing 150 has a storage area. Specifically, the housing 150 is box-shaped and has walls that surround a space that serves as the storage area. However, the box-shaped member that serves as the housing 150 has an opening 150a that connects the internal area (i.e., the storage area) of the housing 150 with the external area. The housing 150 stores the foreign matter removed from the paper separation roller 13 in the storage area.

[0053] The housing 150 is detachable from the main body of the multifunction device 100 (in other words, the paper feeding device 1). By removing the housing 150 from the main body of the multifunction device 100, it is possible to dispose of foreign matter accumulated in the housing 150. After the disposal operation, the housing 150 is reattached to the main body of the multifunction device 100.

[0054] Brush roller 151 is rotatably attached to housing 150. Brush roller 151 has a rotation shaft and a plurality of raised bristles standing up from the outer circumferential surface of the rotation shaft. Brush roller 151 brings the raised bristles into contact with the outer circumferential surface of paper separation roller 13.

[0055] Scraper 152 is attached to housing 150. Scraper 152 contacts the outer peripheral surface of brush roller 151. Brush roller 151 rotates with scraper 152 in contact with its outer peripheral surface. Scraper 152 charges brush roller 151 by contacting the outer peripheral surface of brush roller 151. Brush roller 151 electrically attracts foreign matter adhering to the outer peripheral surface of paper separation roller 13, thereby removing the foreign matter from the outer peripheral surface of paper separation roller 13. Scraper 152 also removes the foreign matter from the outer peripheral surface of brush roller 151 by contacting the outer peripheral surface of brush roller 151. The foreign matter removed from the outer peripheral surface of brush roller 151 falls and is collected in a collection area of ​​housing 150.

[0056] Brush roller 151 is disposed in the storage area of ​​housing 150, with a portion of it exposed to the outside of the storage area through opening 150a of housing 150. The portion of brush roller 151 exposed through opening 150a of housing 150 contacts paper separation roller 13.

[0057] Scraper 152 is entirely disposed in the storage area of ​​housing 150. One end of scraper 152 contacts the outer peripheral surface of brush roller 151, and the other end is attached to housing 150. As a result, foreign matter removed from the outer peripheral surface of brush roller 151 by scraper 152 is stored in the storage area of ​​housing 150.

[0058] In a configuration in which brush roller 151 and scraper 152 are attached to housing 150, simply by removing housing 150 from the main body of multifunction device 100 (i.e., paper feeding device 1), brush roller 151 and scraper 152 can also be removed from the main body of multifunction device 100. This is convenient because maintenance of brush roller 151 and scraper 152 (for example, checking the degree of wear) can be performed at the same time as discarding accumulated matter (foreign matter) accumulated in housing 150.

[0059] Here, the housing 150 has a part of its wall as a guide portion 1501. The guide portion 1501 is a portion that guides the paper P that is transported by the paper separation roller 13.

[0060] Specifically, paper separation roller cleaning unit 15 is disposed upstream of paper separation roller 13 in the paper transport direction and below the transport path of paper P. As a result, the underside of paper P heading toward the paper feed nip between paper feed roller 12 and paper separation roller 13 comes into contact with guide portion 1501, allowing paper P heading toward the paper feed nip to smoothly enter the paper feed nip. As a result, paper separation roller 13 transports paper P smoothly. In other words, guide portion 1501 (i.e., a part of housing 150) guides paper P heading toward the paper feed nip. In yet another way, housing 150 has guide portion 1501 that functions as a guide surface, and guides paper P heading toward the paper feed nip by bringing the underside of paper P heading toward the paper feed nip into contact with guide portion 1501.

[0061] In this embodiment, as described above, a part of the housing 150 (specifically, guide portion 1501) is positioned so that it can come into contact with the paper P. This part of the housing 150 guides the paper P being transported by the paper separation roller 13. This eliminates the need to provide a separate member for guiding the paper P near the area where the housing 150 is located, and prevents the paper feeding device 1 from becoming larger. In other words, the paper separation roller 13 can be properly cleaned while preventing the paper feeding device 1 from becoming larger.

[0062] By properly cleaning the paper separation roller 13, it is possible to effectively remove foreign matter such as paper dust adhering to the paper separation roller 13. As a result, it is possible to prevent problems such as the paper separation roller 13 slipping on the paper P. In other words, it is possible to prevent problems with the transport of the paper P.

[0063] For example, the area around the paper separation roller 13 is covered with an openable cover to improve the efficiency of jam clearance work. By opening the cover, the area around the paper separation roller 13 is exposed. With this configuration, the housing 150 can be attached and detached by opening the cover around the paper separation roller 13 (i.e., the cover for jam clearance), which is convenient.

[0064] Furthermore, in this embodiment, foreign matter adhering to brush roller 151 is removed by scraper 152. This prevents brush roller 151 from insufficiently cleaning paper pickup roller 11. Foreign matter removed from brush roller 151 is collected in housing 150, preventing foreign matter from scattering around paper separation roller 13.

[0065] As a modified example, although not shown, a cleaning unit for cleaning the paper feed roller 12 may be further provided.

[0066] <Configuration of the document feeder> As shown in Fig. 3, the document transport device 2 has a document transport path DP. The document transport device 2 transports the document D along the document transport path DP. The document transport path DP passes through a predetermined position on the contact glass C2, which is the reading position in the transport reading mode. While the document D is being transported by the document transport device 2, the document D passes through a predetermined position on the contact glass C2. This makes it possible to read the document D in the transport reading mode.

[0067] The document transport device 2 is equipped with a document tray TR. Documents D are set on the document tray TR. A document transport path DP runs from the document tray TR to a discharge tray T2 via a predetermined position on the contact glass C2. When a job that involves reading documents D, such as a copy job, is executed in the transport reading mode, the documents D on the document tray TR are sequentially supplied to the document transport path DP and transported along the document transport path DP. As a result, the number of documents D on the document tray TR decreases. The scanned documents D are discharged to the discharge tray T2.

[0068] An original lift plate L2 is disposed on the original tray TR. By setting an original D on the original tray TR, the original D is placed on the original lift plate L2. The original lift plate L2 can be displaced so that the end on the upstream side in the original transport direction swings up and down, with the end on the downstream side in the original transport direction as a fulcrum. In other words, the original lift plate L2 can be raised and lowered. In the following description, raising the original lift plate L2 means that the end on the downstream side in the original transport direction of the original lift plate L2 is displaced upward.

[0069] The document transport device 2 includes a document pickup roller 21. The document pickup roller 21 is supported rotatably around an axis extending in the width direction. The document pickup roller 21 is connected to a motor (not shown) and rotates by receiving driving force from the motor. The document pickup roller 21 is disposed facing the document lift plate L2 in the vertical direction. When documents D are set on the document tray TR, the documents D on the document lift plate L2 and the document pickup roller 21 face each other in the vertical direction. The document pickup roller 21 rotates while coming into contact with the topmost document D on the document lift plate L2. The document pickup roller 21 rotates while coming into contact with the documents D on the document lift plate L2, thereby transporting the documents D on the document lift plate L2. This causes the documents D to be pulled out of the document tray TR.

[0070] During the execution of a job involving the reading of documents D, the document lift plate L2 repeatedly rises and stops rising. The document lift plate L2 rises until it comes into contact with the topmost document D on the document lift plate L2, and stops rising when the contact pressure with the topmost document D on the document lift plate L2 reaches a target value. This allows the documents D on the document tray TR to maintain contact with the document pickup roller 21 even if the number of documents D on the document tray TR decreases.

[0071] The document transport device 2 includes a document feed belt 22. The document feed belt 22 is disposed downstream of the document pickup roller 21 in the document transport direction. The document feed belt 22 is an endless belt. The document feed belt 22 is stretched by a plurality of tension rollers (reference numbers omitted). The plurality of tension rollers are supported rotatably around axes extending in the width direction.

[0072] One of the tension rollers is a drive roller, which rotates by receiving a driving force from a motor (not shown). The document feed belt 22 is driven (i.e., rotates) by the rotation of the drive roller.

[0073] The document transport device 2 includes a document separation roller 23. The document separation roller 23 is disposed downstream in the document transport direction relative to the document pickup roller 21. The document separation roller 23 is supported rotatably around a shaft extending in the width direction.

[0074] The document separation roller 23 is pressed against the document feed belt 22, forming a document feed nip between itself and the document feed belt 22. When a document D is pulled out from the document lift plate L2, the document D enters the document feed nip. The document feed belt 22 and the document separation roller 23 rotate in contact with the document D that has entered the document feed nip, thereby transporting the document D that has entered the document feed nip.

[0075] The document separation roller 23 is connected to a torque limiter (not shown). The torque limiter is disposed on the rotation shaft of the document separation roller 23. The torque limiter disables the rotation shaft of the document separation roller 23 from rotating if the rotation drive force transmitted from the document feed belt 22 to the document separation roller 23 is equal to or less than a threshold value. When the preceding document D and the next document D overlap and enter the document feed nip, the document feed belt 22 contacts the preceding document D and advances it, but the document separation roller 23 does not contact the preceding document D but contacts the next document D. This makes it difficult for the rotation drive force to be transmitted from the document feed belt 22 to the document separation roller 23. As a result, the rotation drive force transmitted from the document feed belt 22 to the document separation roller 23 becomes equal to or less than the threshold value, and the document separation roller 23 does not rotate.

[0076] In this way, while the document feed belt 22 rotates, the document separation roller 23 does not rotate, so that the progress of the next document D, which does not come into contact with the document feed belt 22 but comes into contact with the document separation roller 23, is suppressed. This separates the preceding document D from the next document D. In other words, multi-feeding, in which multiple documents D are fed overlapping each other, is eliminated.

[0077] Although not shown, the document transport device 2 includes one or more document transport roller pairs. The document transport roller pair has a pair of rollers that are in pressure contact with each other. The document transport roller pair has a region between the pair of rollers as a document transport nip. The document transport roller pair transports the document D that has entered the document transport nip by rotating. In other words, the document transport roller pair nip the document D between the pair of rollers and transports the document D by rotating in that state. The document transport roller pair is disposed in the document transport path DP and transports the document D along the document transport path DP.

[0078] <Configuration of the document feed belt cleaning unit> The document transport device 2 includes a document feed belt cleaning unit 24 (see FIG. 4). The document feed belt cleaning unit 24 cleans the document feed belt 22. In this configuration, the document feed belt cleaning unit 24 corresponds to the "cleaning unit," and the document feed belt 22 corresponds to the "rotating body."

[0079] The document feed belt cleaning unit 24 removes foreign matter from the outer peripheral surface of the document feed belt 22. When the document D comes into contact with the outer peripheral surface of the document feed belt 22, paper dust adheres to the outer peripheral surface of the document feed belt 22. When the document feed belt cleaning unit 24 cleans the document feed belt 22, at least paper dust is removed as foreign matter from the outer peripheral surface of the document feed belt 22.

[0080] The document feed belt cleaning unit 24 includes a housing 240, a brush roller 241, and a scraper 242. The brush roller 241 corresponds to the "cleaning member."

[0081] The housing 240 has a storage area. Specifically, the housing 240 is box-shaped and has walls that surround a space that serves as the storage area. However, the box-shaped member that serves as the housing 240 has an opening 240a that connects the internal area (i.e., the storage area) of the housing 240 with the external area. The housing 240 stores foreign matter removed from the document feed belt 22 in the storage area.

[0082] The housing 240 is detachable from the main body of the document transport device 2. By removing the housing 240 from the main body of the document transport device 2, it is possible to discard foreign matter accumulated in the housing 240. After the discarding operation, the housing 240 is reattached to the main body of the document transport device 2.

[0083] The brush roller 241 is rotatably attached to the housing 240. The brush roller 241 has a rotation shaft and a plurality of raised bristles standing on the outer circumferential surface of the rotation shaft. The brush roller 241 brings the raised bristles into contact with the outer circumferential surface of the document feed belt 22.

[0084] Scraper 242 is attached to housing 240. Scraper 242 contacts the outer peripheral surface of brush roller 241. Brush roller 241 rotates with scraper 242 in contact with its outer peripheral surface. Scraper 242 charges brush roller 241 by contacting the outer peripheral surface of brush roller 241. Brush roller 241 electrically attracts foreign matter adhering to the outer peripheral surface of document feed belt 22, thereby removing the foreign matter from the outer peripheral surface of document feed belt 22. Furthermore, scraper 242 removes the foreign matter from the outer peripheral surface of brush roller 241 by contacting the outer peripheral surface of brush roller 241. The foreign matter removed from the outer peripheral surface of brush roller 241 falls and is stored in a storage area of ​​housing 240.

[0085] Brush roller 241 is disposed in the storage area of ​​housing 240, with a portion of it exposed to the outside of the storage area through opening 240a of housing 240. Brush roller 241 brings the portion exposed from opening 240a of housing 240 into contact with document feed belt 22.

[0086] Scraper 242 is entirely disposed in the storage area of ​​housing 240. One end of scraper 242 contacts the outer peripheral surface of brush roller 241, and the other end is attached to housing 240. As a result, foreign matter removed from the outer peripheral surface of brush roller 241 by scraper 242 is stored in the storage area of ​​housing 240.

[0087] In a configuration in which brush roller 241 and scraper 242 are attached to housing 240, simply by removing housing 240 from the main body of document transport device 2, brush roller 241 and scraper 242 can also be removed from the main body of document transport device 2. This is convenient because maintenance of brush roller 241 and scraper 242 (for example, checking the degree of wear) can be performed at the same time as discarding accumulated matter (foreign matter) accumulated in housing 240.

[0088] Here, the housing 240 has a part of its wall as a guide portion 2401. The guide portion 2401 is a portion that guides the document D transported by the document feeding belt 22.

[0089] Specifically, the document feed belt cleaning unit 24 is disposed downstream of the document feed belt 22 in the document transport direction and above the transport path of the document D. As a result, the upper surface of the document D that has passed through the document feed nip between the document feed belt 22 and the document separation roller 23 comes into contact with the guide portion 2401, thereby smoothly transporting the document D that has passed through the document feed nip. As a result, the document feed belt 22 transports the document D well. In other words, the guide portion 2401 (i.e., a part of the housing 240) guides the document D that has passed through the document feed nip. In further words, the housing 240 has the guide portion 2401 that functions as a guide surface, and guides the document D that has passed through the document feed nip by bringing the upper surface of the document D that has passed through the document feed nip into contact with the guide portion 2401.

[0090] In this embodiment, as described above, a part of the housing 240 (specifically, the guide portion 2401) is disposed in a position where it can come into contact with the document D. Then, the part of the housing 240 guides the document D transported by the document feed belt 22. This eliminates the need to provide a separate member for guiding the document D near the area where the housing 240 is disposed, and prevents the document transport device 2 from becoming larger. In other words, the document feed belt 22 can be properly cleaned while preventing the document transport device 2 from becoming larger.

[0091] By properly cleaning the document feed belt 22, it is possible to effectively remove foreign matter such as paper dust adhering to the document feed belt 22. As a result, it is possible to prevent problems such as the document feed belt 22 slipping relative to the document D. In other words, it is possible to prevent poor transport of the document D.

[0092] For example, the area around document feed belt 22 is covered with an openable cover to improve the efficiency of jam clearance work. Opening the cover exposes the area around document feed belt 22. This configuration is convenient because the housing 240 can be attached or detached by opening the cover around document feed belt 22 (i.e., the cover for jam clearance).

[0093] Furthermore, in this embodiment, foreign matter adhering to brush roller 241 is removed by scraper 242. This makes it possible to prevent brush roller 241 from insufficiently cleaning document feed belt 22. Foreign matter removed from brush roller 241 is collected in housing 240, making it possible to prevent foreign matter from scattering around document feed belt 22.

[0094] As a modified example, although not shown, a cleaning unit for cleaning the document pickup roller 21 may be further provided, or a cleaning unit for cleaning the document separation roller 23 may be further provided.

[0095] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0096] 1. Paper feeder (sheet transport device) 2 Document transport device (sheet transport device) 10 Printing Department 11 Paper pickup roller (rotating body) 13 Paper separation roller (rotating body) 14 Paper pickup roller cleaning unit (cleaning unit) 15 Paper separation roller cleaning unit (cleaning unit) 20 Image reading unit 22 Document feed belt (rotating body) 24 Document feed belt cleaning unit (cleaning unit) 100 Multifunction devices (image forming devices, image reading devices) 140, 150, 240 enclosure 141, 151, 241 Brush roller (cleaning material) 142, 152, 242 scraper D Original (sheet) P Paper (sheet)

Claims

1. a rotating body that rotates in contact with a sheet to transport the sheet; a cleaning unit that cleans the rotating body, The cleaning unit includes: a cleaning member that comes into contact with the outer peripheral surface of the rotating body to remove foreign matter from the outer peripheral surface of the rotating body; a housing that stores the foreign matter removed from the outer circumferential surface of the rotating body, A sheet conveying device in which a part of the housing is disposed at a position where it can come into contact with the sheet and guides the sheet conveyed by the rotating body.

2. The cleaning unit further includes a scraper that contacts the outer circumferential surface of the cleaning member to remove foreign matter from the outer circumferential surface of the cleaning member, The sheet conveying device according to claim 1 , wherein the housing stores the foreign matter removed from the outer peripheral surface of the cleaning member by the scraper.

3. the cleaning member and the scraper are attached to the housing; The sheet transporting device according to claim 2 , wherein the housing is detachable from a main body of the sheet transporting device.

4. The sheet conveying device according to claim 1 , wherein the cleaning member is a brush roller that rotates in contact with the outer circumferential surface of the rotating body.

5. a sheet conveying device according to any one of claims 1 to 4; a printing unit that prints on the sheet transported by the sheet transport device.

6. a sheet conveying device according to any one of claims 1 to 4; an image reading unit that reads an image formed on the sheet conveyed by the sheet conveying device.

Images