This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2019-181141 filed Oct. 1, 2019.
The present disclosure relates to an image forming apparatus.
An image forming apparatus that includes a body and a drawer unit drawable from the body is known. The image forming apparatus has a sheet transport path structure in which a transport path member of the body forming a sheet transport path and a transport path member of the drawer unit are separable. The image forming apparatus forms an image on a sheet transported along the sheet transport path. The sheet transport path structure includes a transport path member of the body that restricts a movement of one side of a sheet to a predetermined direction, a transport path member of the drawer unit facing the transport path member and slidably assembled with the transport path member to restrict a movement of another side of a sheet while having a predetermined distance between itself and the transport path member, and a cleaning mechanism disposed at a sliding start point of the transport path member of the drawer unit. The cleaning mechanism includes a cleaning member longer than or equal to a predetermined length from an end of the transport path member of the drawer unit to an end of the transport path member of the body facing the end. When the drawer unit is pulled out or attached, a distal end of the cleaning member slides over the transport path member of the body while being in contact with the transport path member (Japanese Unexamined Patent Application Publication No. 2011-241012).
An image forming apparatus that includes a sheet tray, an apparatus body, a sheet inverting unit, a pulled-in sheet container, and a pushing unit is known. The sheet tray accommodates sheets subjected to image formation. The apparatus body removably accommodates the sheet tray, and has a jam removal port on a side from which the sheet tray is pulled out and below a tray holding space. The sheet inverting unit is formed in the apparatus body to pull in sheets downward to invert the sheets. The pulled-in sheet container is formed at the lowermost portion in the apparatus body substantially horizontally to be continuous with the jam removal port to accommodate sheets pulled in downward by the sheet inverting unit. The pushing unit moves in the pulled-in sheet container toward the pull-out side of the sheet tray in association with a pull-out operation of the sheet tray, and pushes a jammed sheet out through the jam removal port while being in contact with the jammed sheet in the pulled-in sheet container during this movement (Japanese Unexamined Patent Application Publication No. 2004-35129).
Aspects of non-limiting embodiments of the present disclosure relate to reliable removal of sheets remaining on a transport path and cleaning of the transport path.
Aspects of certain non-limiting embodiments of the present disclosure address the features discussed above and/or other features not described above. However, aspects of the non-limiting embodiments are not required to address the above features, and aspects of the non-limiting embodiments of the present disclosure may not address features described above.
According to an aspect of the present disclosure, there is provided an image forming apparatus according to an aspect of the present disclosure that includes a drawer unit, a sheet inverting unit, a sheet guide plate, and a projection. The drawer unit is drawable from an apparatus body. The sheet inverting unit is disposed in the apparatus body, and pulls a sheet into a lower portion of the drawer unit to invert the sheet. The sheet guide plate is disposed on the sheet inverting unit to face the drawer unit, and includes a recess extending in a pull-out direction of the drawer unit that crosses a direction in which the sheet is transported. The projection protrudes toward the recess from a portion of a lower surface of the drawer unit facing the sheet guide plate near a pull-out start point in the pull-out direction and on a rear of a transport area of the sheet.
Exemplary embodiments of the present disclosure will be described in detail based on the following figures, wherein:
With reference to the drawings, the present disclosure will be further described below in detail using exemplary embodiments and specific examples. The present disclosure, however, is not limited to these exemplary embodiments and specifications.
In the following description with reference to the drawings, it should be noted that the drawings are schematic, the dimensional ratios throughout the drawings are different from the actual ones, and components other than needed are omitted as appropriate for ease of understanding.
For ease of understanding the following description, the front-rear direction is referred to as an X-axis direction, the left-right direction is referred to as a Y-axis direction, and the vertical direction is referred to as a Z-axis direction in the drawings.
(1) Entire Structure and Operation of Image Forming Apparatus
(1.1) Entire Structure of Image Forming Apparatus
The image forming apparatus 1 includes an image forming portion 10, a sheet feeder 20 attached to a lower portion of the image forming portion 10, and a sheet discharge portion 30 disposed at an end of the image forming portion 10 and to which printed sheets P are discharged.
The image forming portion 10 includes a system controller (not illustrated), an exposure device 12, a photoconductor unit 13, a developing device 14, a transfer device 15, a sheet transport device 16a, and a fixing device 17. The image forming portion 10 forms a toner image on a sheet P fed from the sheet feeder 20 from image information received from an image processing portion 40.
The sheet feeder 20, including sheet trays 21 and 22 as an example of drawer units, is disposed on the bottom of the image forming portion 10 to feed sheets to the image forming portion 10. Specifically, the sheet feeder 20 includes the multiple sheet trays 21 and 22, which accommodate sheets P of different types (different in, for example, material, thickness, size, or grain orientation) of recording media, to feed sheets P picked up from either one of the multiple sheet trays 21 and 22 to the image forming portion 10. The sheet trays 21 and 22 are drawable to an operator (in the −Y direction), and pulled toward the operator to be replenished with sheets P.
The sheet discharge portion 30 discharges sheets P to which images are output by the image forming portion 10 and fixed by the fixing device 17. The sheet discharge portion 30 thus includes a transport path 31, along which sheets P subjected to fixing are transported, and a discharged sheet container T1, to which the sheets P are discharged. The sheet discharge portion 30 also includes a sheet inverting unit 18, which inverts the sheets P and feeds the sheets P to a sheet transport device 16b for outputting images on both sides of the sheets P. The sheet discharge portion 30 may have a function of performing postprocessing on a sheet bundle output from the image forming portion 10, such as cutting or stapling.
(1.2) Structure and Operation of Image Forming Portion
In the above image forming apparatus 1, a sheet P picked up from one of sheet mount portions of the sheet feeder 20 designated for each print job at the timing of image formation is fed to the image forming portion 10.
The photoconductor units 13 are arranged side by side below the exposure devices 12, and each include a photoconductor drum 131, serving as an image carrier driven to rotate. In the rotation direction of each photoconductor drum 131, a charging device 132, the exposure device 12, the developing device 14, a first-transfer roller 152, and a cleaning blade 134 are arranged.
Each developing device 14 includes a development housing 141, which accommodates a developer. The development housing 141 accommodates a development roller 142 disposed to face the photoconductor drum 131.
The developing devices 14 have substantially the same structure except for developers accommodated in the development housings 141 to form toner images of yellow (Y), magenta (M), cyan (C), and black (K).
The surface of the rotating photoconductor drum 131 is charged by the charging device 132 to have electrostatic latent images formed with latent-image-forming light emitted from the exposure device 12. Electrostatic latent images formed on the photoconductor drum 131 are developed into toner images by the development roller 142.
The transfer device 15 includes an intermediate transfer belt 151, the first-transfer rollers 152, and a second-transfer roller 153. The intermediate transfer belt 151 receives superposed toner images of respective colors formed by the photoconductor drums 131 of the respective photoconductor units 13. The first-transfer rollers 152 sequentially transfer (first-transfer) the toner images of different colors formed by the photoconductor units 13 to the intermediate transfer belt 151. The second-transfer roller 153 collectively transfers (second-transfers) the toner images of different colors that have been transferred to the intermediate transfer belt 151 in a superposed manner to sheets P, which are recording medium.
The toner images of different colors formed on the photoconductor drums 131 of the photoconductor units 13 are sequentially electrostatically transferred (first-transferred) onto the intermediate transfer belt 151 by the first-transfer rollers 152 to which a predetermined first transfer voltage is applied from a power supply (not illustrated) controlled by the system controller at first transfer portions where the intermediate transfer belt 151 and the photoconductor drums 131 are in contact, to form a superposed toner image from toner of different colors.
Along with the movement of the intermediate transfer belt 151, the superposed toner image on the intermediate transfer belt 151 is transported to a second transfer portion TR at which the second-transfer roller 153 is pressed against a back-up roller 165 with the intermediate transfer belt 151 interposed therebetween.
At the timing when a superposed toner image is transported to the second transfer portion TR, a sheet P is fed to the second transfer portion TR from the sheet feeder 20. A predetermined second transfer voltage is applied from a power supply (not illustrated) controlled by a system controller 11 to the back-up roller 165, facing the second-transfer roller 153 with the intermediate transfer belt 151 interposed therebetween, to collectively transfer a multilayer toner image on the intermediate transfer belt 151 to the sheet P.
Toner remaining on the surface of each photoconductor drum 131 is removed by the corresponding cleaning blade 134, and the surface of the photoconductor drum 131 is recharged by the corresponding charging device 132.
The sheets P to which toner images have been transferred by the transfer device 15 are transported to the fixing device 17 via the sheet transport device 16a while having the toner images unfixed. The sheets P transported to the fixing device 17 have the toner images fixed by heating and pressing operations with a pair of a heating module 17a and a pressing module 17b.
The sheets P subjected to fixing are stacked on the discharged sheet container T1. To output images on both surfaces of the sheets P, the sheets P are inverted by the sheet inverting unit 18, and fed to the second transfer portion TR of the image forming portion 10 again. After the transfer of the toner images and fixing of the transferred images, the sheets P are fed to the sheet discharge portion 30. The sheets P fed to the sheet discharge portion 30 are subjected to postprocessing such as cutting or stapling, as appropriate.
(2) Sheet Inverting Unit
The structure of the sheet inverting unit 18 and removal of remaining sheets will be described below with reference to the drawings.
(2.1) Structure of Sheet Inverting Unit
As illustrated in
In the image forming apparatus, when the sheet inverting unit 18 inverts a sheet P, the sheet P needs to be constantly held by reverse rollers 16d. If, for any reason, a sheet P of a small size, in particular, deviates from the reverse rollers 16d, the sheet P falls from the sheet transport path 16c to the pulled-in sheet container 181, and is left in the pulled-in sheet container 181 as a jammed sheet.
When an image forming operation is continued while leaving such jamming in the pulled-in sheet container 181, subsequent sheets P become caught on a remaining sheet P1 left in the pulled-in sheet container 181, and the sheets P become jammed sequentially. Thus, the remaining sheet P1 left in the pulled-in sheet container 181 after falling from the sheet transport path 16c needs to be immediately removed.
However, in the image forming apparatus 100 according to a comparative example illustrated in
Whenever a sheet P falls in the pulled-in sheet container 181, a user has to ask a maintenance worker to remove the jammed sheet. The remaining-sheet removal operation is troublesome also for the maintenance worker because he/she has to completely remove the sheet tray 22 from the apparatus body to remove the remaining sheet P1.
As illustrated in
The pulled-in sheet container 181 includes the sheet guide plate 182, which faces the lowest sheet tray 22 of the sheet feeder 20 and guides the pulled-in sheets P in the horizontal direction (X direction). As illustrated in
As illustrated in
As illustrated in
(2.2) Removal of Remaining Sheets
When the sheets P deviate from the reverse rollers 16d on the sheet transport path 16c and fall on the pulled-in sheet container 181, the sheets P are left unremovable as a remaining sheet P1 on the sheet guide plate 182, as illustrated in
After the remaining sheet P1 is left on the sheet guide plate 182, when the sheet tray 22 is pulled toward the operator (in the −Y direction), as illustrated in
Now, the structure of the sheet inverting unit 18A and cleaning of the sheet guide plate 182 will be described below with reference to the drawings.
As illustrated in
The pulled-in sheet container 181 includes the sheet guide plate 182, which faces the lowermost sheet tray 22 of the sheet feeder 20 to guide the pulled-in sheets P in the horizontal direction (X direction). As in the case of the first exemplary embodiment, the sheet guide plate 182 has recesses 182a, which extend in the pull-out direction (Y direction) of the sheet tray 22 that crosses the transport direction of the sheets P.
As illustrated in
In addition, second projections 184 protrude toward the sheet guide plate 182 from portions of the lower surface 22a of the sheet tray 22 facing the sheet guide plate 182 near the pull-out start point in the pull-out direction (−Y direction) and on the rear of a transport area of the sheets P.
As in the projections 183, each of the second projections 184 has a base end 184a fixed to the lower surface 22a of the sheet tray 22, and a distal end 184b in contact with a surface 182b of the sheet guide plate 182. The projections 183 and the second projections 184 having such a structure are preferably formed from elastic foam. Particularly, desirable examples of elastic foam are polyurethane foam and silicone foam to prevent damages on the sheet guide plate 182 or breakage of the projections 183 and 184 due to long time use, as the second projections 184, in particular, move relative to the surface 182b of the sheet guide plate 182 while being in contact with the surface 182b to clean the sheet guide plate 182.
As illustrated in
Thus, the user that cleans the sheet guide plate 182 of the sheet inverting unit 18A to remove the remaining sheet P1 is prevented from becoming stained through the pull-out operation of the sheet tray 22.
When the remaining sheet P1 is left on the sheet guide plate 182, as illustrated in
As illustrated in
As illustrated in
The foregoing description of the exemplary embodiments of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalents.
Number | Date | Country | Kind |
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JP2019-181141 | Oct 2019 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
8899578 | Tomatsu | Dec 2014 | B2 |
9056745 | Harada | Jun 2015 | B2 |
9290340 | Yamamoto | Mar 2016 | B2 |
9302884 | Sugiura | Apr 2016 | B2 |
20140291929 | Nguyen | Oct 2014 | A1 |
20210107306 | Kimura | Apr 2021 | A1 |
Number | Date | Country |
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2004035129 | Feb 2004 | JP |
2011-241012 | Dec 2011 | JP |
Number | Date | Country | |
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20210094783 A1 | Apr 2021 | US |