JP2022135272A - Sheet feeding device and image formation device - Google Patents

Abstract

To provide a sheet feeding device capable of maintaining paper powder removal performance of a paper powder removal roller.SOLUTION: A paper powder removal part 67 of a sheet feeding device comprises: a first paper powder removal roller 81 which is rotated in contact with a pickup roller 63 to recover paper powder from the pickup roller 63; a second paper powder removal roller 83 which is rotated in contact with a feed roller 65 to recover paper powder from the feed roller 65; a first scraping member 85 which contacts with the first paper powder removal roller 81 to scrap the paper powder recovered by the first paper powder removal roller 81; a second scraping member 87 which contacts with the second paper powder removal roller 83 to scrap the paper powder recovered by the second paper powder removal roller 83; and a storage part 89 which recovers and stores the paper powder scraped by the first scraping member 85 and the second scraping member 87.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sheet feeding device that feeds sheets and an image forming apparatus that includes the sheet feeding device.

The sheet feeding device includes a pickup roller that feeds a sheet from a sheet bundle accommodated in a sheet feeding cassette, and a feed roller that conveys the sheet fed by the pickup roller downstream in the feeding direction. there is The feed roller contacts the retard roller to form a separation nip, and the sheet is conveyed while being loosened in the separation nip.

Since the pickup roller and the feed roller rotate in contact with the sheet, paper dust is likely to be generated due to friction with the sheet. In the separation nip, paper dust is also generated due to friction between sheets. If such paper dust adheres to each roller, the sheet conveying force may be reduced. Alternatively, if paper dust scatters and adheres to the photosensitive drum or mixes with the developer, image defects may occur. Therefore, an image forming apparatus may be provided with a paper dust removing unit as described in Japanese Patent Application Laid-Open No. 2002-200013.

The paper dust removing means includes a paper dust removing roller that electrostatically attracts paper dust from the first conveying roller, a first sponge that scrapes the paper dust attracted from the paper dust removing roller, and the removed paper dust. and a paper dust reservoir to be collected.

JP-A-2003-81477

However, in the paper dust removing means described in Patent Document 1, the first sponge scrapes the paper dust from the paper dust removing roller, so there is a risk that the first sponge will become clogged and the paper dust removing performance will deteriorate. There is

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding device capable of maintaining the paper dust removing performance of the paper dust removing roller and an image forming apparatus including the sheet feeding device.

In order to solve the above-described problems, the sheet feeding apparatus of the present invention includes a pickup roller that feeds a sheet in a predetermined feeding direction by rotating in contact with the sheet, and a pickup roller downstream of the pickup roller in the feeding direction. a feed roller that is arranged on the side of the pickup roller and that picks up the sheet fed by the pickup roller and conveys it to the downstream side; a first paper dust removing unit for removing and collecting paper dust adhering to the first paper dust removing unit rotating in contact with the pickup roller to collect paper dust from the pickup roller a removing roller, a second paper dust removing roller that rotates in contact with the feed roller and collects paper dust from the feed roller, and the first paper dust removing roller that contacts the first paper dust removing roller. and a second scraping member that scrapes the paper dust collected by the second paper dust removing roller in contact with the second paper dust removing roller. and a storage section for collecting and storing the paper dust scraped by the first scraping member and the second scraping member.

In the sheet feeding device of the present invention, the first scraping member and the second scraping member may be elastic films.

In the sheet feeding device of the present invention, the first paper dust removing roller and the second paper dust removing roller are charged by contact with the first scraping member and the second scraping member, respectively, and the pick-up roller and collecting paper dust electrostatically from the feed roller.

The sheet feeding device of the present invention further includes a paper feed holder that supports the pickup roller, the feed roller, and the paper dust removing section, and the paper feed holder is attached to a storage section provided in the apparatus main body. It may be characterized by being detachable.

In the sheet feeding device of the present invention, the storage section may be detachable from the sheet feeding holder.

An image forming apparatus according to the present invention includes the sheet feeding device and an image forming section that forms an image on the sheet conveyed by the sheet feeding device.

According to the present invention, since paper dust is removed without using a sponge, it is possible to prevent deterioration in paper dust removal performance.

1 is a front view schematically showing the internal structure of an image forming apparatus according to an embodiment of the invention; FIG. 4 is a cross-sectional view of a sheet feeding unit of the sheet feeding device according to one embodiment of the present invention; FIG. 3 is a perspective view of a sheet feeding unit of the sheet feeding device according to one embodiment of the present invention; FIG. 2 is a rear perspective view of a unit housing portion of the image forming apparatus according to the embodiment of the present invention; FIG. 2 is a front perspective view of a unit housing portion of the image forming apparatus according to the embodiment of the present invention; FIG.

An image forming apparatus and a sheet feeding apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

First, referring to FIG. 1, the overall configuration of an image forming apparatus 1 according to this embodiment will be described. FIG. 1 is a cross-sectional view schematically showing the internal structure of the image forming apparatus 1. As shown in FIG. In the following description, the right side of the paper surface of FIG. 1 is the front side (front side) of the image forming apparatus 1 . Fr, Rr, L, and R in each figure indicate the front side, rear side, left side, and right side of the image forming apparatus, respectively.

An apparatus body 3 of the image forming apparatus 1 includes a sheet feeding device 5 , an electrophotographic image forming section 7 , a fixing device 9 , and a discharge device 11 . A discharge tray 13 is formed on the upper surface of the apparatus main body 3 .

An opening 3a is formed in the rear surface of the device main body 3. As shown in FIG. The opening 3 a is opened and closed by the rear cover 15 . The rear cover 15 is supported by the device main body 3 so as to be rotatable about its lower end. Further, inside the rear cover 15, a transport unit 17 is supported by the apparatus main body 3 so as to be rotatable about its lower end. A sheet main transport path 19 is formed between the apparatus main body 3 and the transport unit 17 . The sheet is transported along the main transport path 19 in an upward transport direction from the sheet feeding device 5 through the image forming unit 7 and the fixing device 9 toward the ejection device 11 . The upstream side and the downstream side in the following description refer to the upstream side and the downstream side in the sheet conveying direction. Moreover, let the direction orthogonal to a conveyance direction be a width direction.

A reverse transport path 21 is formed between the transport unit 17 and the rear cover 15 . The reverse conveying path 21 branches off from the main conveying path 19 on the downstream side of the fixing device 9 and joins the main conveying path 19 on the downstream side of the sheet feeding device 5 . By rotating the rear cover 15 downward, the reverse transport path 21 is opened, and by rotating the transport unit 17 together with the rear cover 15 downward, the main transport path 19 is opened.

A cassette insertion port 23 and a manual paper feed port 25 are formed on the front surface of the apparatus main body 3 . The cassette insertion opening 23 is formed in the lower part of the front surface, and the manual paper feeding opening 25 is formed above the cassette insertion opening 23 . A manual feeding path 27 is formed between the manual feeding port 25 and the main feeding path 19 . A cassette accommodating portion 29 communicating with the cassette insertion opening 23 is formed in the lower portion of the device main body 3 . The cassette accommodating portion 29 communicates with the opening 3a.

The sheet feeding device 5 includes a sheet feeding cassette 31 in which sheets are stored, and a sheet feeding section 33 that feeds sheets along the sheet feeding direction from the sheet feeding cassette 31 toward the main conveying path 19 . . In the following description of the sheet feeding device 5, the terms "upstream side" and "downstream side" refer to the upstream side and the downstream side in the sheet feeding direction. The sheet feeding device 5 will be described later.

The image forming unit 7 includes four process cartridges 35 corresponding to toners of four colors (yellow, magenta, cyan, and black), an intermediate transfer belt 37 that circulates, and transfer rollers 39 . The four process cartridges 35 are arranged along the running direction of the intermediate transfer belt 37 so as to face the lower track of the intermediate transfer belt 37 . The four process cartridges 35 superimpose toner images of respective colors on the running intermediate transfer belt 37 . The formed toner image is transferred onto a sheet conveyed along the main conveying path 19 at a transfer nip formed between the transfer roller 39 and the intermediate transfer belt 37 .

A fixing device 9 fixes the toner image transferred to the sheet onto the sheet. The discharging device 11 discharges the sheet on which the toner image is fixed. The discharged sheets are stacked on the discharge tray 13 .

Next, the sheet feeding device 5 will be described with reference to FIGS. 1, 2 and 3. FIG. 2 is a side view showing the feeding section 33 of the sheet feeding device 5, and FIG. 3 is a perspective view showing the feeding unit 51 of the feeding section 33 of the sheet feeding device 5. FIG. The sheet feeding device 5 includes the sheet feeding cassette 31 and the feeding section 33 as described above.

As shown in FIG. 1, the paper feed cassette 31 includes a body portion 41 in which sheets are stored, a stacking plate 43 on which the sheets are placed in the body portion 41, and a lift plate for tilting the stacking plate 43. 45 and . The placing plate 43 is arranged at the rear end portion of the bottom plate of the main body portion 41, and the rear end portion of the accommodated sheet is placed thereon. The mounting plate 43 is supported by the main body 41 so as to be rotatable upward about the front end. The lift plate 45 is arranged between the bottom plate of the main body portion 41 and the mounting plate 43 and is rotatable upward about the front end portion. The paper feed cassette 31 is attached to and detached from the cassette accommodating portion 29 through the cassette insertion opening 23 .

Next, the feeding section 33 will be described mainly with reference to FIGS. 2 and 3. FIG. The feeding section 33 includes a feeding unit 51 and a retard roller 53 .

As shown in FIG. 2 , the paper feed unit 51 includes a paper feed holder 61 , a pickup roller 63 , a feed roller 65 and a paper dust remover 67 .

The paper feed holder 61 is a substantially rectangular parallelepiped box-shaped member with an open bottom, and has a top plate, a front plate, and left and right side plates. A projection 71 (see FIG. 3) projecting forward is formed on the outer surface of the front plate. A spring receiving portion is further formed on the outer surface of the front plate. A coil spring 73 is supported on the upper surface of the spring receiving portion in a posture along the vertical direction. . Cylindrical left and right bearing portions 75L and 75R (only the left bearing portion 75L is shown in FIG. 3) are formed at the downstream end portions (rear end portions) of the left and right side plates.

Both ends of the rotating shaft 63 a of the pickup roller 63 are rotatably supported between the upstream ends (front ends) of the left and right side plates of the paper feed holder 61 . Both ends of the rotary shaft 65a of the feed roller 65 are rotatably supported by left and right bearing portions 75L and 75R of the paper feed holder 61. As shown in FIG. A right end portion of the rotation shaft 65a of the feed roller 65 protrudes outward from the right bearing portion 75R. A gear fixed to the rotary shaft 63a of the pickup roller 63 and a gear fixed to the rotary shaft 65a of the feed roller 65 (both not shown) are connected via an idle gear 77 (see FIG. 3).

As shown in FIG. 2, the paper dust removing section 67 has first and second paper dust removing rollers 81 and 83, first and second scraping members 85 and 87, and a storage section 89. ing. The paper dust removing section 67 is arranged between the pickup roller 63 and the feed roller 65 and supported by the paper feed holder 61 .

The first paper dust removing roller 81 has a diameter smaller than that of the pickup roller 63 . Both ends of the rotating shaft of the first paper dust removing roller 81 are rotatably supported by upper end portions of left and right side plates of the paper feed holder 61 . The paper dust removing roller 81 contacts and rotates with the pickup roller 63 . The first paper dust removing roller 81 is made of a material that is easily electrified to a polarity opposite to that of paper dust. In general, paper dust tends to be positively charged, so the first paper dust removing roller 81 is made of fluorine-based resin, such as Teflon (registered trademark) or polyethylene, which is easily negatively charged.

The second paper dust removing roller 83 has a diameter smaller than that of the feed roller 65 . The second paper dust removing roller 83 is arranged downstream of the first paper dust removing roller 81, and both ends of the rotating shaft are rotatably supported by the upper ends of the left and right side plates of the paper feed holder 61. . The second paper dust removing roller 83 is driven to rotate in contact with the feed roller 65 . The second paper dust removing roller 83 is also made of fluorine-based resin that is easily charged to the opposite polarity of the paper dust.

The first and second paper dust removing rollers 81 and 83 are exposed through an opening 61 a formed in the upper plate of the paper feed holder 61 .

The first scraping member 85 is a resin (for example, PET) film. The first scraping member 85 is supported by the paper feed holder 61 in a substantially vertical posture, and is slightly deformed to the surface of the first paper dust removing roller 81 from the downstream side in the rotation direction of the first paper dust removing roller 81 . I am in contact while In this example, the first scraping member 85 is pressed against the first paper dust removing roller 81 from behind along the substantially horizontal direction. Specifically, the leading edge of the first scraping member 85 is in contact with the surface of the first paper dust removing roller 81 .

The second scraping member 87 is a resin (for example, PET) film. The second scraping member 87 is supported by the paper feed holder 61 in a substantially vertical posture, and is slightly spread over the surface of the second paper dust removing roller 83 from the downstream side in the rotational direction of the second paper dust removing roller 83 . It is pressed while deforming. In this example, the second scraping member 87 contacts the second paper dust removing roller 83 substantially from below. Specifically, the tip edge of the second scraping member 87 is in contact with the surface of the second paper dust removing roller 83 .

Both scraping members 85 and 87 are in contact with both paper dust removing rollers 81 and 83 with a pressure that does not hinder the driven rotation of both paper dust removing rollers 81 and 83 .

The reservoir 89 has a box shape with an open top and is arranged below the scraping members 85 and 87 . The storage portion 89 is detachably supported by the paper feed holder 61 by snap-fitting or the like.

As shown in FIG. 2 , the retard roller 53 is held by a retard holder 91 . The retard holder 91 is arranged in the rear portion of the cassette accommodating portion 29 (see FIG. 1) and is biased upward by a biasing member (not shown). The retard roller 53 is supported by a rotating shaft 53a via a torque limiter (not shown). The retard roller 53 stops until a torque exceeding a predetermined torque is applied, and when the torque exceeding the predetermined torque is applied, the retard roller 53 idles about the rotating shaft 53a.

The paper feed unit 51 is attached to and detached from a unit accommodating section 101 provided in the apparatus main body 3 . The unit housing portion 101 will be described mainly with reference to FIGS. 4 and 5. FIG. 4 is a perspective view of the unit accommodating portion 101 as seen from the rear, and FIG. 5 is a perspective view of the unit accommodating portion 101 as seen from the front.

The unit accommodating portion 101 is formed in the widthwise central portion of the rear end portion of the upper wall of the cassette accommodating portion 29 (see FIG. 1).

As shown in FIG. 4, left and right side wall portions 103L and 103R are formed at the rear end portion of the upper wall of the cassette accommodating portion 29 so as to face each other with a predetermined gap in the width direction. The tip of the drive input shaft 105 is supported by the left side wall 103L. The drive input shaft 105 is rotated by being driven by a motor (not shown). As shown in FIG. 5, engaging pieces 107 with long holes 107a protrude downward from the front sides of the left and right side walls 103L and 103R.

In order to mount the paper feed unit 51 in the unit housing portion 101, first, the rear cover 15 and the transport unit 17 (see FIG. 1) are rotated to open the opening 3a and open the main transport path 19. As shown in FIG. Then, the paper supply unit 51 is inserted between the left and right side walls 103L and 103R from the opening 3a with the front plate of the paper supply holder 61 facing forward, and as shown in FIG. The formed protrusion 71 is snap-fitted to the engaging piece 107 of the unit accommodating portion 101 . Further, as shown in FIG. 4, the left end of the rotation shaft 65a of the feed roller 65 is connected to the tip of the drive input shaft 105 supported by the left side wall portion 103L, and the rotation shaft 65a of the feed roller 65 is The right end portion is supported by the right side wall portion 103R.

When the paper feed unit 51 is mounted in the unit housing portion 101 in this manner, the coil spring 73 is compressed between the paper feed holder 61 and the upper wall of the cassette housing portion 29 as shown in FIG. The paper feed holder 61 is urged downward. As a result, the paper feed holder 61 is urged downward around the rotating shaft 65 a of the feed roller 65 . That is, the pickup roller 63 is urged downward. Also, as shown in FIG. 2, feed roller 65 contacts retard roller 53 to form a separation nip.

In order to remove the paper feed unit 51 from the unit storage section 101, first, the rear cover 15 and the transport unit 17 are rotated to open the opening 3a to open the main transport path 19. As shown in FIG. Then, the user puts his or her hand through the opening 3a and rotates the sheet feeding unit 51 downward about the rotating shaft 65a of the feed roller 65 to release the snap-fit connection between the engaging piece 107 and the protrusion 71. FIG. Further, the connection between the left end portion of the rotation shaft 65a of the feed roller 65 and the tip portion of the drive input shaft 105 is removed, and the right end portion of the rotation shaft 65a of the feed roller 65 is removed from the right side wall portion 103R. After that, the paper feeding unit 51 is pulled out from the unit housing portion 101 .

A sheet feeding operation and a paper dust removing operation of the sheet feeding device 5 having the above configuration will be described. When the sheet feeding cassette 31 containing sheets is mounted in the cassette housing portion 29, the lift plate 45 rotates to tilt the mounting plate 43 upward as shown in FIG. As a result, the uppermost sheet S rises to a predetermined feeding height. As a result, the pickup roller 63 comes into contact with the uppermost sheet S of the sheet bundle and is pushed up to rotate the paper feed holder 61 upward, and the pickup roller 63 rises to the paper feed height.

After that, the drive input shaft 105 is driven to rotate the feed roller 65 . The rotation of the feed roller 65 is transmitted to the pickup roller 63 via the idle gear 79, and the pickup roller 63 rotates. As a result, the uppermost sheet S with which the pickup roller 63 is in contact is fed downstream along the feeding direction. The sent out sheet S is handled by the separation nip and conveyed to the main conveying path 19 .

As shown in FIG. 2, when the pickup roller 63 and the feed roller 65 rotate, the first and second paper dust removing rollers 81 and 83 follow the pickup roller 63 and the feed roller 65 to rotate. Further, the first and second paper dust removing rollers 81 and 83 contact the first and second scraping members 85 and 87 while rotating. This contact negatively charges the first and second paper dust removing rollers 81 and 83 . Then, when the paper dust D adheres to the pickup roller 63 and the feed roller 65, the pickup roller 63 and the feed roller 65 are picked up at or near the contact portion between the pickup roller 63 and the feed roller 65 and the first and second paper dust removal rollers 81 and 83. Paper dust D is electrostatically attracted from the roller 63 and the feed roller 65 to the first and second paper dust removing rollers 81 and 83 . That is, the paper dust D on the pickup roller 63 and the feed roller 65 is removed. The removed paper dust D adheres to the first and second paper dust removing rollers 81 and 83 .

The paper dust adhering to the first and second paper dust removing rollers 81 and 83 in this way is removed by the first and second scraping members 85 and 87 at the contact portions with the first and second scraping members 85 and 87 . is scraped off. The scraped paper dust D drops into the storage section 89 due to its own weight and is collected. Specifically, the paper dust scraped by the first scraping member 85 falls along the first scraping member 85 and falls from the first scraping member 85 to the reservoir 89 . The paper dust scraped by the second scraping member 87 directly drops into the storage section 89 .

The paper dust D collected in the storage section 89 is discarded when the paper feed unit 51 is removed from the unit storage section 101 for maintenance or replacement of the feed roller 65 and the pickup roller 63, for example. The paper feed unit 51 is removed from the unit storage section 101 as described above. Thereafter, the storage section 89 is removed from the paper feed holder 61 and the paper dust is discarded.

As described above, the paper dust removing unit 67 of the present invention causes the paper dust adhering to the pickup roller 63 and the feed roller 65 to adhere to the paper dust removing rollers 81 and 83 once, and then to the paper dust removing rollers 81 and 83. Scraping members 85 and 87 scrape off adhering paper dust. Since the paper dust is removed without using a sponge in this way, deterioration of the paper dust removing performance can be prevented.

In addition, the paper dust removing rollers 81 and 83 are charged by contact with the scraping members 85 and 87 and electrostatically remove paper dust from the pickup roller 63 and the feed roller 65, so that both rollers are less likely to be damaged. .

Furthermore, since the paper dust removing section 67 is provided in the detachable paper feeding unit 51 , the paper dust can be easily discarded by removing the paper feeding unit 51 . Furthermore, if the storing section 89 is configured to be detachable from the paper feed holder 61, it is easier to dispose of the paper dust.

The first and second scraping members 85 and 87 may be formed of elastic blades that are thicker than the film.

Although the invention has been described with respect to certain embodiments, the invention is not limited to the above embodiments. Those skilled in the art can modify the above embodiments without departing from the scope and spirit of the present invention.

1 Image forming device 5 Sheet feeding device 7 Image forming unit 61 Paper feed holder 63 Pickup roller 65 Feed roller 67 Paper dust removing unit 81 First paper dust removing roller 83 Second paper dust removing roller 85 First scraping member 87 2 Scraping member 89 Storing part 101 Receiving part

Claims (6)

a pickup roller that rotates in contact with the sheet to feed the sheet in a predetermined feeding direction;
a feed roller disposed on the downstream side of the pickup roller in the feeding direction for handling the sheet fed by the pickup roller and conveying the sheet to the downstream side;
a paper dust removing unit disposed between the pickup roller and the feed roller for removing and collecting paper dust adhering to the pickup roller and the feed roller;
The paper dust removing unit
a first paper dust removing roller that rotates in contact with the pickup roller to collect paper dust from the pickup roller;
a second paper dust removing roller that rotates in contact with the feed roller to collect paper dust from the feed roller;
a first scraping member that contacts the first paper dust removing roller and scrapes the paper dust collected by the first paper dust removing roller;
a second scraping member that contacts the second paper dust removing roller and scrapes the paper dust collected by the second paper dust removing roller;
A sheet feeding device, comprising: a storage unit that collects and stores paper dust scraped by the first scraping member and the second scraping member. 2. The sheet feeding device according to claim 1, wherein said first scraping member and said second scraping member are elastic films. The first paper dust removing roller and the second paper dust removing roller are charged by contact with the first scraping member and the second scraping member, respectively, and electrostatically remove paper from the pickup roller and the feed roller. 3. The sheet feeding device according to claim 1, wherein powder is collected. The apparatus further comprises a paper feed holder that supports the pickup roller, the feed roller, and the paper dust removing section, wherein the paper feed holder is detachable from a storage section provided in the apparatus main body. The sheet feeding device according to any one of claims 1 to 3. The sheet feeding apparatus according to any one of claims 1 to 4, wherein the storage section is detachable from the sheet feeding holder. The sheet feeding device according to any one of claims 1 to 5;
and an image forming unit that forms an image on the sheet conveyed by the sheet feeding device.

Images