The present invention relates to a sheet conveyance apparatus for conveying sheets, and an image forming apparatus and an image forming system equipped with the same.
Generally, image forming apparatuses such as printers are provided with a door configured to open a conveyance path through which sheets are conveyed, which is used for sheet jam and for maintenance. Hitherto, a printer having a first door supported in an openable/closable manner with respect to an apparatus body of a printer, and a second door supported in an openable and closable manner with respect to the first door has been proposed (refer to Japanese Patent Application Laid-Open Publication No. 2011-13299). The first door is configured to open a conveyance path that extends in a vertical direction, and the second door is configured to open a conveyance path in the vicinity of a pivot shaft of the first door.
The second door disclosed in the above-described Japanese Patent Application Laid-Open Publication No. 2011-13299 is arranged at a lower portion of the printer, such that if a wide opening angle is ensured for the second door, accessibility to a lever used for opening and closing the second door will be deteriorated. If a small opening angle is set for the second door, space for treating sheet jam formed by opening the second door is narrowed, and the jam processing performance is deteriorated.
According to an aspect of the present invention, a sheet conveyance apparatus includes an apparatus body including a conveyance portion configured to convey a sheet, a door supported in an openable/closable manner with respect to the apparatus body around a pivot shaft, and configured to pivot to a first position that is opened with respect to the apparatus body and to a second position that is opened further with respect to the apparatus body than the first position, the door being configured to expose the conveyance portion at both the first and second positions, a pivot member pivotably supported with respect to the apparatus body around the pivot shaft, an urging portion provided between the door and the pivot member, and configured to urge the door and the pivot member to approach each other so that the door and the pivot member are pivoted integrally with respect to the apparatus body, and a regulating portion configured to regulate pivoting of the pivot member at a predetermined pivot angle with respect to the apparatus body in a case where the door is positioned at the first position, wherein the door is configured to be retained at the first position in a state where no external force is applied to the door, is pivoted relatively with respect to the pivot member against urging force of the urging portion while the door moves from the first position to the second position, and is urged toward the first position by the urging portion in a case where the door is positioned at the second position.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Now, a first embodiment will be described with reference to the drawings. In the following description, positional relationships in up and down, right and left and front and rear directions are described based on the image forming apparatus viewed from a front side, that is, from the viewpoint of
A printer 201 serving as an image forming apparatus according to the present embodiment is a full-color laser beam printer adopting an electrophotographic system. The printer 201 includes, as illustrated in
The printer body 201A includes an image forming portion 201B for forming an image on a sheet P, and a fixing unit 220 configured to fix the image on the sheet P. Between the reading unit 202 and the printer body 201A is formed a discharge space S to which the sheet P is discharged, and a sheet discharge tray 223 on which the discharged sheet P is supported is provided in the discharge space S. Further, the printer body 201A is provided with a plurality of (two, according to the present embodiment) cassette sheet feeding devices 230 configured to feed sheets P to the image forming portion 201B, and a door 100 supported in an openable/closable manner with respect to the printer body 201A. The door 100 is arranged lower than the image forming portion 201B. Each cassette sheet feeding device 230 includes a cassette 1 that stores sheets P, a pickup roller 8 serving as a conveyance portion for conveying sheets P, a feed roller 9 and a retard roller 10 that separate and convey the sheets P one by one.
The image forming portion 201B is a so-called four-drum full-color image forming portion including a laser scanner 210, four process cartridges 211, and an intermediate transfer unit 201C. The process cartridges form toner images of respective colors, which are yellow (Y), magenta (M), cyan (C) and black (K). The respective process cartridges 211 include a photosensitive drum 212, a charging unit 213, a developing unit 214, a cleaner not shown, and so on. A toner cartridge 215 that stores toner of each color is attached in a detachable manner to the printer body 201A above the image forming portion 201B.
The intermediate transfer unit 201C includes an intermediate transfer belt 216 wound around a drive roller 216a and a tension roller 216b, and the intermediate transfer belt 216 is arranged above the four process cartridges 211. The intermediate transfer belt 216 is arranged to contact the photosensitive drum 212 of the respective process cartridges 211 and driven to rotate in a counterclockwise direction by the drive roller 216a that is driven by a driving unit not shown. The intermediate transfer unit 201C includes primary transfer rollers 219 that contact an inner circumferential surface of the intermediate transfer belt 216 at positions opposing to respective photosensitive drums 212, and a primary transfer portion TP1 is formed as a nip portion between the intermediate transfer belt 216 and the photosensitive drum 212. Further, the image forming portion 201B includes a secondary transfer roller 217 that contacts an outer circumferential surface of the intermediate transfer belt 216 at a position opposed to the drive roller 216a. A secondary transfer portion TP2 is formed as a nip portion between the secondary transfer roller 217 and the intermediate transfer belt 216 where toner image borne on the intermediate transfer belt 216 is transferred to the sheet P.
In the respective process cartridges 211 configured as above, an electrostatic latent image is formed on the surface of the photosensitive drum 212 by a laser scanner 210, and toner is supplied from the developing unit 214, by which toner images of respective colors charged to negative polarity are formed. The toner images are sequentially transferred at the respective primary transfer portions TP1 to the intermediate transfer belt 216 in multiple layers by applying transfer bias voltage of positive polarity to the primary transfer roller 219, and a full-color toner image is formed on the intermediate transfer belt 216.
In parallel with the image forming process, the sheet P fed from the cassette sheet feeding device 230 is conveyed toward a registration roller pair 240, and the registration roller pair 240 corrects skewing of the sheets. The registration roller pair 240 conveys the sheet P to the secondary transfer portion TP2 at a matched timing with a transfer timing of the full-color toner image formed on the intermediate transfer belt 216. The toner image borne on the intermediate transfer belt 216 is secondarily transferred to the sheet P at the secondary transfer portion TP2 by having the transfer bias voltage of positive polarity applied to the secondary transfer roller 217.
The sheet P to which toner image has been transferred is heated and pressed at the fixing unit 220, by which the color image is fixed to the sheet P. The sheet P having the image fixed thereto is discharged through a first sheet discharge roller pair 225a or a second sheet discharge roller pair 225b to the sheet discharge tray 223 and supported thereon. If images are to be formed on both sides of the sheet P, the sheet P is passed through the fixing unit 220 and switched back by a reverse conveyance roller pair 222 that is capable of rotating in normal and reverse directions. Then, the sheet P is re-conveyed to the secondary transfer portion TP2 through a re-conveyance path R, and an image is formed on a rear side thereof.
As illustrated in
The second angle α2 is greater than the first angle α1 (α2>α1), and a processing space C2 between the door 100 positioned at the second position and the printer body 201A is greater than a processing space C1 between the door 100 positioned at the first position and the printer body 201A. Therefore, jamming of sheets can be treated more easily and jam processing performance is improved when the door 100 is positioned at the second position than at the first position.
Meanwhile, a height H1 from a bottom surface 260 of the printer body 201A to the handle 101 of the door 100 positioned at the first position is higher than a height H2 from the bottom surface 260 to the handle 101 of the door 100 positioned at the second position. Therefore, the user can access the handle 101 more easily when the door 100 is positioned at the first position than when it is positioned at the second position, and the user can operate the door 100 easily by holding the handle 101. That is, the accessibility is higher when the door 100 is positioned at the first position.
As illustrated in
A coil portion 103C of an urging spring 103 composed of a torsion spring is wound around the pivot shaft 102C, wherein a first end 103A of the urging spring 103 is connected to the door cover 102 of the door 100 and a second end 103B thereof is connected to a hole portion 112 formed to the pivot member 110. As illustrated in
Next, an opening operation and retaining configuration of the door 100 will be described. As illustrated in
If the door 100 is opened to the first position, the stopper 232 contacts the end portion 111a of the long hole portion 111 formed on the pivot member 110. Thereby, the pivot member 110 is regulated from pivoting in an opening direction beyond the predetermined pivot angle. In this state, as illustrated in
In a state where the door 100 is positioned at the second position, a moment MD2 generated by the own weight of the door 100 in the direction opening the door 100 and a moment MS2 generated by the urging spring 103 in the direction closing the door 100 are applied to the door 100. The moment MS2 is set greater than the moment MD2 (MS2>MD2), and the first and second contact portions 102A and 110A are separated, such that the door 100 attempts to return to the first position. Therefore, if the user removes his/her hand from the door 100, the door 100 returns to the first position by urging force of the urging spring 103.
According to this configuration, even if the user removes his/her hand from the door 100, the door 100 will be retained at the first position, as illustrated in
As illustrated in
When the user opens the door 100 from the closed state to the first position, the user must operate the handle 101, but once the door 100 is opened to the first position, the user can push the door 100 to be opened to the second position without operating the handle 101. If the user removes his/her hand from the door 100 positioned at the second position, the door 100 is returned to the first position by the urging spring 103, and the door 100 can be closed easily, such that the operation performance of the door 100 is improved.
As illustrated in
As illustrated in
Meanwhile, as illustrated in
As described, as the angle formed by the arrow D direction and the direction R2 in which the door closes increases and approximates 90°, it becomes difficult for the sheet conveyance apparatus 300 to close the door 100. According to the present embodiment, even if the door 100 is opened by the user, it is retained at the first position as illustrated in
In a state where the door 100 is positioned at the first position, the angle formed by the arrow D direction and the direction R2 in which the door 100 closes is relatively small, and the door 100 can be closed easily. Furthermore, the possibility of the sheet conveyance apparatus 300 colliding strongly against the door 100 and causing damage to the door 100 or the sheet conveyance apparatus 300 can be reduced.
Next, a second embodiment of the present invention will be described. Compared to the first embodiment, the second embodiment changes the positional relationship of the stopper, the door and the pivot member, and the urging force of the urging spring. Therefore, the components similar to the first embodiment are either not shown in the drawing or denoted with the same reference numbers.
In a state where the door 200 is opened to the third position, as illustrated in
When the door 200 moves from the third position to the first position, as illustrated in
In a state where the door 200 reaches the first position, a moment MD1′ generated by the own weight of the door 200 in a direction opening the door 200 and a moment MS1′ generated by the urging spring 103 in a direction closing the door 200 are applied to the door 200. Moment MS1′ is set to be equal to moment MD1′, and the balance between these moments maintains the door 200 at the first position.
As illustrated in
In a state where the door 200 is positioned at the second position, a moment MD2 generated by the own weight of the door 200 in a direction opening the door 200 and a moment MS2 generated by the urging spring 103 in a direction closing the door 200 are applied to the door 200. The moment MS2 is set greater than the moment MD2 (MS2>MD2), and the first and second contact portions 102A and 110A are separated, such that the door 200 attempts to return to the first position. Therefore, if the user removes his/her hand from the door 200, the door 200 returns to the first position by an urging force of the urging spring 103.
According to this configuration, similar to the first embodiment, the accessibility to the door 200 and the jam processing performance can be realized at the same time. Further, as described with respect to
According to any of the embodiments described above, the urging spring 103 is provided between the pivot member 110 and the door, but the present invention is not restricted thereto. For example, a configuration can be adopted where the urging spring 103 is provided between the printer body 201A (including the stopper 232) and the door, and the pivot member 110 may be omitted. In this state, the urging force of the urging spring 103 is set to be balanced with the door positioned at the first position.
According to any of the above-described embodiments, the door is supported in an openable/closable manner on the printer body 201A, but the present invention is not restricted thereto. For example, a configuration can be adopted where a processing door supported in an openable/closable manner on the printer body 201A and capable of opening a re-conveyance path R is provided, and the above-described door (100 or 200) can be provided in an openable/closable manner to the processing door. Further, the printer body 201A should include at least one conveyance portion for conveying the sheets, such as the feed roller 9 or the retard roller 10, instead of the pickup roller 8, and configured such that the conveyance portion is exposed if the door is opened.
The above-described embodiments have been described based on the printer 201 adopting an electrophotographic system, but the present invention is not restricted thereto. For example, the present invention can be applied to an image forming apparatus adopting an ink-jet system that forms images on sheets by injecting ink through nozzles. Moreover, the present invention can be applied to an external sheet conveyance apparatus 300 or to a finisher that performs various processing such as punching and sorting of sheets.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2017-206325, filed on Oct. 25, 2017, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2017-206325 | Oct 2017 | JP | national |
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Number | Date | Country | |
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20190119056 A1 | Apr 2019 | US |