This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application Nos. 2018-198560, filed on Oct. 22, 2018, and 2019-188128, filed on Oct. 11, 2019, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein.
This disclosure relates to a sheet conveying device and an image forming system incorporating the sheet conveying device.
Sheet conveying devices are provided with a technique in which, when printing a sheet such as a flat sheet, air is blown to a sheet bundle to separate one sheet, which is a conveyance target, from other sheets. Such a technique restrains lifting of a sheet that is likely to be caused at an upstream region (a trailing end) of the sheet in a sheet conveyance direction when separating the sheet from the other sheets of the sheet bundle. Consequently, such sheet conveying devices prevent paper jam due to sheet conveyance failure.
At least one aspect of this disclosure provides a sheet conveying device including a sheet container, an air blower, and a guide. The sheet container is configured to store a plurality of sheets. The air blower is configured to blow air to the plurality of sheets to separate a single sheet from subsequent sheets of the plurality of sheets. The guide is configured to contact a surface of the single sheet separated from the subsequent sheets of the plurality of sheets over a given region downstream from any position of an upstream region in a sheet conveyance direction to guide the single sheet. The upstream region is from an upstream end to a center of the single sheet in the sheet conveyance direction.
Further, at least one aspect of this disclosure provides an image forming system including the above-described sheet conveying device and an image forming apparatus configured to form an image on a sheet of the plurality of sheets from the sheet conveying device.
Further, at least one aspect of this disclosure provides a sheet conveying device including a sheet container, an air blower, a guide, and a support. The sheet container is configured to store a plurality of sheets. The air blower is configured to blow air to the plurality of sheets to separate a single sheet from subsequent sheets of the plurality of sheets. The guide is configured to contact a surface of the single sheet separated from the subsequent sheets of the plurality of sheets to guide the single sheet. The support is configured to support both ends of the guide in a sheet conveying direction of the single sheet. Both ends of the guide are movable with respect to the support by reciprocating motion in a direction of thickness of the single sheet.
Further, at least one aspect of this disclosure provides an image forming system including the above-described sheet conveying device and an image forming apparatus configured to form an image on the single sheet of the plurality of sheets from the sheet conveying device.
Further, at least one aspect of this disclosure provides a sheet conveying device including a sheet container, an air blower, a guide, and a support. The sheet container is configured to store a plurality of sheets. The air blower is configured to blow air to the plurality of sheets to separate a single sheet from subsequent sheets of the plurality of sheets. The guide is configured to contact a surface of the single sheet separated from the subsequent sheets of the plurality of sheets to guide the single sheet. The guide has a virtual axis extending along a sheet conveyance direction. The support is configured to support both ends of the guide in the sheet conveying direction of the single sheet. Both ends of the guide are movable with respect to the support by rotational motion about a virtual shaft that extends along the sheet conveyance direction.
Further, at least one aspect of this disclosure provides an image forming system including the above-described sheet conveying device and an image forming apparatus configured to form an image on the single sheet of the plurality of sheets from the sheet conveying device.
An exemplary embodiment of this disclosure will be described in detail based on the following figured, wherein:
It will be understood that if an element or layer is referred to as being “on”, “against”, “connected to” or “coupled to” another element or layer, then it can be directly on, against, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, if an element is referred to as being “directly on”, “directly connected to” or “directly coupled to” another element or layer, then there are no intervening elements or layers present. Like numbers referred to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements describes as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors herein interpreted accordingly.
Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layer and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.
The terminology used herein is for describing particular embodiments and examples and is not intended to be limiting of exemplary embodiments of this disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Descriptions are given, with reference to the accompanying drawings, of examples, exemplary embodiments, modification of exemplary embodiments, etc., of a sheet conveying device and an image forming system according to exemplary embodiments of this disclosure. Elements having the same functions and shapes are denoted by the same reference numerals throughout the specification and redundant descriptions are omitted. Elements that do not demand descriptions may be omitted from the drawings as a matter of convenience. Reference numerals of elements extracted from the patent publications are in parentheses so as to be distinguished from those of exemplary embodiments of this disclosure.
This disclosure is applicable to any sheet conveying device, and is implemented in the most effective manner in any inkjet image forming system.
In describing preferred embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this disclosure is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes any and all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, preferred embodiments of this disclosure are described.
Descriptions are given of an embodiment applicable to a sheet conveying device and an image forming system incorporating the sheet conveying device, with reference to the following figures.
It is to be noted that elements (for example, mechanical parts and components) having the same functions and shapes are denoted by the same reference numerals throughout the specification and redundant descriptions are omitted.
Further, size (dimension), material, shape, and relative positions used to describe each of the components and units are examples, and the scope of this disclosure is not limited thereto unless otherwise specified.
As illustrated in
The image forming system 2 may have a configuration of a known inkjet type image forming system.
Furthermore, the term “sheet” (including the plurality of sheets S) has no limitation in the material, thickness, shape, size, weight, and the like. For example, the sheet is not limited to indicate a paper material but also includes a recording medium such as thread, fiber, cloth, leather, metal, synthetic resin, plastic, glass, wood, ceramics, or the like. Further, the inkjet image forming system may be replaced with an electrophotographic image forming system in which an image is formed with toner.
The sheet conveying device 1 includes a sheet feeding unit 6 and a pair of registration rollers 7. The sheet feeding unit 6 and the pair of registration rollers 7 are housed in an interior of a housing 1p of the sheet conveying device 1. A door is openable and closable to be attached to the housing 1p. Closing the door maintains the interior of the housing 1p closely sealed from outside. On the other hand, by opening the door, the sheet feeding unit 6 that functions as a sheet feeder is pulled out from the housing 1p of the sheet conveying device 1. Thus, for example, the sheets S (e.g., the plurality of sheets S) are set and replenished with respect to the sheet feeding unit 6 and various types of maintenance are performed.
A sheet bundle (the plurality of sheets S) including the sheets S is disposed in the sheet feeding unit 6. The sheet feeding unit 6 blows air to the sheet bundle to separate a sheet S1 that functions as a conveyance target (for example, a single sheet of uppermost sheets of the sheet bundle) one by one from the other sheets S2 (in other words, subsequent sheets S2) of the sheet bundle, so that the sheet S1 is fed out from the sheet feeding unit 6. The pair of registration rollers 7 conveys the sheet S (e.g., the sheet S1 of the uppermost sheets of the sheet bundle) fed from the sheet feeding unit 6 to the image forming apparatus 3.
According to the above-described configuration, for example, each sheet S of the sheet bundle (the plurality of sheets) is sent out one by one from the sheet feeding unit 6. The leading end of each of the sheets S (the plurality of sheets) sent out from the sheet feeding unit 6 reaches the pair of registration rollers 7. Thereafter, the pair of registration rollers 7 is driven at a given timing. Thus, the sheet S is conveyed to the image forming apparatus 3.
It is to be noted that the details of the sheet feeding unit 6 are described below.
The image forming apparatus 3 includes a receiving cylinder 8, a transfer cylinder 9, a sheet carrying drum 10, an air suction unit 11, and an ink discharge unit 12. Sheet grippers are provided on a surface of the receiving cylinder 8, a surface of the transfer cylinder 9, and an outer circumferential surface of the sheet carrying drum 10. Each of the sheet grippers grips the leading end of the sheet S (in other words, a downstream end of the sheet S in a sheet conveyance direction). The air suction unit 11 is disposed within an inner loop of the sheet carrying drum 10. A plurality of dispersed suction holes is formed on the surface of the sheet carrying drum 10. The air suction unit 11 sucks air to generate a negative pressure, so that a suction airflow directed to the interior of the sheet carrying drum 10 is generated in each of the plurality of dispersed suction holes.
Further, the ink discharge unit 12 is disposed facing (opposing) the surface of the sheet carrying drum 10. The ink discharge unit 12 is configured to discharge inks of four colors of cyan (C), magenta (M), yellow (Y), and black (K). The ink discharge unit 12 includes individual ink discharge heads 12K, 12Y, 12M, and 12C for each of the four-color inks. Here, by controlling the ink discharge heads 12K, 12Y, 12M, and 12C, the respective inks of four colors are discharged toward the surface of the sheet carrying drum 10.
According to this configuration, after the sheet S has been fed out from the sheet conveying device 1 to the sheet carrying drum 10, while the sheet gripper of the receiving cylinder 8 grips the leading end of the sheet S, the sheet S is conveyed to the sheet carrying drum 10 as the receiving cylinder 8 rotates. After the sheet S has been conveyed to the sheet carrying drum 10, the sheet gripper of the sheet carrying drum 10 grips the leading end of the sheet S. At this time, the suction airflow described above is generated on the surface of the sheet carrying drum 10 (specifically, on the plurality of suction holes in the surface of the sheet carrying drum 10). According to this configuration, while being attracted by suction airflow on (the plurality of suction holes of) the surface of the sheet carrying drum 10, the sheet S is conveyed as the sheet carrying drum 10 rotates (in other words, as the surface of the sheet carrying drum 10 moves).
While the sheet S is conveyed along (the plurality of suction holes of) the surface of the sheet carrying drum 10, the ink discharge heads 12K, 12Y, 12M, and 12C are controlled. Respective inks are discharged from the ink discharge heads 12K, 12Y, 12M, and 12C toward the surface of the sheet S. According to this ink discharge, an image corresponding to previously set image information is formed on the surface of the sheet S. Thereafter, the leading end of the sheet S reaches the transfer cylinder 9. At this time, the transfer cylinder 9 is driven at a given timing. Thus, the sheet S is conveyed to the drying device 4 along with movement of the surface of the transfer cylinder 9 while the leading end of the sheet S is gripped by the transfer cylinder 9.
The drying device 4 includes a conveyance unit 13 and a drying unit 14. According to this configuration, the sheet S conveyed to the drying device 4 is dried by the drying unit 14 while being conveyed by the conveyance unit 13. In the drying process, for example, moisture of the image (ink) formed on the surface of the sheet S is evaporated. At this time, the image (ink) is fixed to the surface of the sheet S. Thus, the sheet S is conveyed to the sheet ejecting device 5 while curling (deformation due to curvature) is restrained.
The sheet ejecting device 5 includes a sheet ejection tray 5t. The sheet ejection tray 5t is configured to accumulate (stack) a plurality of sheets S. According to this configuration, the sheets S (the plurality of sheets S) conveyed from the drying device 4 are sequentially collected and stored in the sheet ejection tray 5t.
Variation of Image Forming System 2.
As one variation of the image forming system 2, for example, a pre-processing device may be interposed between the sheet conveying device 1 and the image forming apparatus 3. The pre-processing device is configured to perform pre-processing of image formation. As the pre-processing, for example, the pre-processing device may perform a pre-application process that applies processing liquid on the sheet S before the image formation. The processing liquid reacts with ink to reduce bleeding of the ink to the sheet S. However, the content of the pre-processing is not particularly limited to the process as described above.
As another variation of the image forming system 2, for example, a post-processing device may be interposed between the drying device 4 and the sheet ejecting device 5. The post-processing device is configured to perform post-processing of image formation. As the post-processing, for example, the post-processing device may perform a sheet reverse process that reverses the sheet S with the image (ink) formed on the front face side, before the image formation. By reversing the sheet S and then conveying the sheet S to the image forming apparatus 3 again, an image (ink) may be formed on the back face of the sheet S.
Sheet Feeding Unit 6 of Sheet Conveying Device 1.
In
The unit housing 15 includes a sheet set opening 15a and a sheet containing portion 15b. In the example of
The guide mechanism 16 is rotatably disposed with respect to the unit housing 15. When the sheet S is conveyed, the guide mechanism 16 restrains the rise of the sheet S1 (see
The guide mechanism 16 includes a frame 20 and guides 21. The frame 20 has a hollowed rectangular shape and is coupled to the unit housing 15 (the sheet feeding unit 6) via hinges 22 (to be more specific, two hinges 22). In the example illustrated in
As illustrated in
The first support 24a is disposed on the upstream side in the sheet conveyance direction Dc. The second support 24b is disposed on the downstream side in the sheet conveyance direction Dc. Specifically, the first support 24a is disposed upstream from the second support 24b in the sheet conveyance direction Dc (in other words, the second support 24b is disposed downstream from the first support 24a in the sheet conveyance direction Dc). The first support 24a and the second support 24b are disposed extending in the sheet conveyance direction Dc and facing each other in parallel in the sheet conveyance direction Dc. The first support 24a and the second support 24b have both ends (in other words, one end and an opposed end) and have shapes identical to each other with the same dimension (lengths).
The two connecting portions, which are the first connecting portion 25a and the second connecting portion 25b, are disposed between the first support 24a and the second support 24b. In this case, the first connecting portion 25a is mutually connected to one end of the first support 24a and one end of the second support 24b. The second connecting portion 25b is mutually connected to the opposed end of the first support 24a and the opposed end of the second support 24b. The first connecting portion 25a and the second connecting portion 25b are disposed extending in the sheet conveyance direction Dc and facing each other in parallel in the width direction Db. The first connecting portion 25a and the second connecting portion 25b are mutually set to have the same dimensions (lengths) and the same shapes.
The reinforcement member 26 is disposed between the first connecting portion 25a and the second connecting portion 25b. In other words, the reinforcement member 26 is disposed at a position where the first support 24a and the second support 24b are divided into two equal parts in the width direction Db and extend along the sheet conveyance direction Dc. An end fence 27 is disposed on the reinforcement member 26 (the frame 20). One end of the end fence 27 is supported by the reinforcement member 26 and the opposed end of the end fence 27 extends downward along the vertical direction Da. The end fence 27 is configured to reciprocate along the reinforcement member 26. In this case, the end fence 27 is moved in a state in which the plurality of sheets S is stored in the sheet containing portion 15b. Accordingly, the trailing end of the sheet S (the upstream side end in the sheet conveyance direction Dc) is aligned by the end fence 27.
Further, the frame 20 includes a plurality of receiving portions (i.e., the first receiving portions 23a and the second receiving portions 23b). The first receiving portions 23a and the second receiving portions 23b that functions as a plurality of receiving portions support the guides 21 to be detachably attachable to the frame 20. The first receiving portions 23a are a plurality of receiving portions disposed along the first support 24a. The second receiving portions 23b are a plurality of receiving portions disposed along the second support 24b. For these reasons, the first receiving portions 23a and the second receiving portions 23b are disposed along the width direction Db that intersects the sheet conveyance direction Dc. In
The first receiving portions 23a and the second receiving portions 23b are aligned along the sheet conveyance direction Dc and disposed facing each other. In this case, for example, the guides 21 (for example, first hooks 21a and second hooks 21b) are placed on the two first receiving portions 23a and the two second receiving portions 23b aligned each other along the sheet conveyance direction Dc. Accordingly, the guides 21 are disposed along the sheet conveyance direction Dc.
The first receiving portions 23a and the second receiving portions 23b share the same shape and size. Each of the first receiving portions 23a has a recessed shape vertically recessed from the upper end to the lower end of a part of the first support 24a, as viewed in the vertical direction Da. Similarly, each of the second receiving portions 23b has a recessed shape vertically recessed from the upper end to the lower end of a part of the second support 24b, as viewed in the vertical direction Da. Each of the receiving portions, i.e., the first receiving portions 23a and the second receiving portions 23b, has an upper end 23t that is open and a lower end 23e that is closed, as viewed in the vertical direction Da.
According to this configuration, the guides 21 (including the first hooks 21a and the second hooks 21b) are inserted from the upper end 23t that is open, to the first receiving portions 23a and the second receiving portions 23b. Accordingly, the guides 21 (the first hooks 21a and the second hooks 21b) are placed on the lower end 23e that is closed while being in contact with the lower end 23e. As a result, the guides 21 are supported by the frame 20 via the first receiving portions 23a and the second receiving portions 23b.
Further, the first receiving portions 23a and the second receiving portions 23b, each having a recessed shape, are bent at the upper end 23t side (the opening side). In
According to this configuration, the frame 20 is rotated via the hinges 22. For example, the frame 20 is rotated so as to open the sheet set opening 15a (the sheet containing portion 15b). While the frame 20 is being rotated, the guides 21 (the first hooks 21a and the second hooks 21b) do not climb over the upper end 23t (the opening side) that is bent. That is, the guides 21 (the first hooks 21a and the second hooks 21b) are supported by the first receiving portions 23a and the second receiving portions 23b. Accordingly, the guides 21 (the first hooks 21a and the second hooks 21b) do not come out of (drop from) the first receiving portions 23a and the second receiving portions 23b. As a result, the guides 21 are constantly supported by the frame 20 via the first receiving portions 23a and the second receiving portions 23b.
Each of the guides 21 has a sheet contact portion 21p and the hooks (i.e., the first hook 21a and the second hook 21b). In the example illustrated in
Here, the length of each of the guides 21 (that is, the sheet contact portion 21p) is set in correspondence with the length (along the sheet conveyance direction Dc) of the sheet S stored in the sheet containing portion 15b. Specifically, the entire length of the sheet contact portion 21p is set to contact throughout the entire length of the surface of the sheet S1, which functions as a conveyance target, from an upstream region (i.e., the trailing end of the sheet S1) to a downstream region (i.e., the leading end of the sheet S1) in the sheet conveyance direction Dc. To be more specific, the entire length of the sheet contact portion 21p is set to contact throughout the entire length of the surface of the sheet S1 (a conveyance target), over an area from the upstream region (i.e., the trailing end of the sheet S1) to the downstream region (i.e., the leading end of the sheet S1) via a center of the sheet S1 in the sheet conveyance direction Dc. Here, the term “upstream region” is a concept including a region between the trailing end of the sheet S1 in the sheet conveyance direction Dc and the center of the sheet S1, and the term “downstream region” is a concept including a region between the leading end of the sheet S1 and the center of the sheet S1 in the sheet conveyance direction Dc. It is to be noted that, instead of the configuration according to the present embodiment, each of the guides 21 (that is, the sheet contact portion 21p) may be set to contact the sheet S1 that is one of the uppermost sheets, functioning as a conveyance target, of the plurality of sheets S stored in the sheet containing portion 15b, from the upstream region to the center of the sheet S1 in the sheet conveyance direction Dc.
Each of the first hooks 21a is integrated with the one end of the sheet contact portion 21p. Further, each of the first hooks 21a is bent toward the opposed end (i.e., the corresponding opposed one of the second hooks 21b) of the sheet contact portion 21p. On the other hand, each of the second hooks 21b is integrated with the opposed end of the sheet contact portion 21p. Each of the second hooks 21b is bent toward the opposed end (i.e., the corresponding opposed one of the first hooks 21a) of the sheet contact portion 21p. The first hooks 21a and the second hooks 21b are set to have the same shape and diameter.
According to this configuration, any of the first hooks 21a is inserted into (placed onto) a corresponding one of the first receiving portions 23a of the first support 24a and, at the same time, any of the second hooks 21b is inserted into (placed onto) a corresponding one of the second receiving portions 23b of the second support 24b. Accordingly, the sheet contact portion 21p is supported by the first support 24a and the second support 24b via the first hook 21a and the second hook 21b, respectively. As a result, the guide 21 is supported by the frame 20. In the above-described state, the guide 21 maintains the attitude in which the guide 21 hangs down with the own weight along the vertical direction Da (also referred to as the direction of gravitational force). In other words, the guide 21 maintains the attitude in which the sheet contact portion 21p is positioned immediately below the first hook 21a and the second hook 21b, viewed in the direction of gravitational force. At this time, the guide 21 (specifically, the sheet contact portion 21p) is disposed parallel to the surface of the sheet S1 that is one of the uppermost sheets (that is, the sheet S1 as a conveyance target) of the plurality of sheets S stored in the sheet containing portion 15b and is disposed parallel to the sheet conveyance direction Dc.
As an example illustrated in
Here, as one assumption, the rotational motion 21r of the guide 21 is performed by rotating about a virtual axis 21f extending along the sheet conveyance direction Dc (for example, an axis formed by extending both the first hook 21a and the second hook 21b in the sheet conveyance direction Dc). The reciprocating motion 21m of the guide 21 is assumed, for example, to be a reciprocating motion moving, at sheet feeding, along a direction in which the sheet S1 that functions as a conveyance target separates from the subsequent sheets S2 (in other words, along a thickness direction intersecting (or perpendicular to) the surface of the sheet S1). In this case, the reciprocating motion 21m of the guides 21 corresponds to a reciprocating motion in which the sheet contact portion 21p lifts or lowers, viewed in the vertical direction Da, when the first hooks 21a and the second hooks 21b rotate about the virtual axis 21f (the line of axis) of rotation of the guides 21.
To be more specific, the positional change of each of the guides 21 (movement of each of the guides 21 by the rotational motion 21r or the reciprocating motion 21m) described above is likely to generate according to types (for example, the thickness, weight, and so on) of the sheet S1 that functions as a conveyance target. For example, if the sheet S1 functioning as a conveyance target is a lightweight, thin sheet, the position of the guide 21 that is brought to contact the sheet S1 does not change. In other words, since the pressing force from the lightweight, thin sheet S1 applies small pressing force to the guide 21, the guide 21 is maintained in the initial hanging posture without changing the position. By contrast, if the sheet S1 functioning as a conveyance target is a heavyweight, thick sheet, the position of the guide 21 that is brought to contact the sheet S1 changes. In other words, since the pressing force from the heavyweight, thick sheet S1 applies large pressing force to the guide 21, the guide 21 performs the rotational motion 21r about the virtual axis 21f or the reciprocating motion 21m along the thickness direction.
In a case in which the plurality of sheets S is inserted into the sheet containing portion 15b of the sheet feeding unit 6, for example, the frame 20 is rotated via the hinges 22 while supporting the above-described four guides 21. In this case, the sheet feeding unit 6 is pulled out from the housing 1p of the sheet conveying device 1.
As described above, the sheet feeding unit 6 is provided, together with the frame 20 supporting the guides 21, in the housing 1p of the sheet conveying device 1. In this case, as the door of the housing 1p opens, the sheet feeding unit 6 is pulled out (removed), together with the frame 20, to the outside of the housing 1p.
Here, as illustrated in
Then, the frame 20 is rotated to close the sheet set opening 15a (the sheet containing portion 15b). Thereafter, the sheet feeding unit 6 is stored, together with the frame 20 supporting the guides 21, in the housing 1p of the sheet conveying device 1. Then, the door of the housing 1p is closed. Accordingly, the sheet feeding unit 6 is stored in the housing 1p again.
According to this configuration with the end fence 27 being mounted on the frame 20 (the reinforcement member 26), both a process in which the end fence 27 is retreated from the sheet set opening 15a (the sheet containing portion 15b) and another process in which the sheet set opening 15a (the sheet containing portion 15b) is opened are performed simultaneously with a single rotation of the frame 20. Thus, the setting efficiency of the sheet S to the sheet containing portion 15b is enhanced.
As illustrated in
As illustrated in
The air blowing device 28 (that functions as an air blower) includes a housing 28a and a nozzle 28b. The housing 28a is configured to supply compressed air to the nozzle 28b. The nozzle 28b is configured to blow air supplied by the housing 28a. In the example of
The air suction device 29 includes an attraction belt 29a in a form of an endless loop, a pair of rollers 29b and 29c (for example, a drive roller 29b and a driven roller 29c), and an air suction unit 29d. The attraction belt 29a is wound around the pair of rollers, that is, the drive roller 29b and the driven roller 29c. The attraction belt 29a has a plurality of suction holes are scattered over the entire surface. The plurality of suction holes penetrates through the thickness of the attraction belt 29a. In this case, for example, as the drive roller 29b rotates, the attraction belt 29a is moved in a sheet feed direction.
The air suction unit 29d is disposed inside the loop of the attraction belt 29a and communicates with the pair of rollers, that is, the drive roller 29b and the driven roller 29c. The air suction unit 29d is configured to generate the negative pressure to the lower side of the attraction belt 29a (in other words, the region opposed to the one sheet S1 of the uppermost sheets of the plurality of sheets S contained in the sheet containing portion 15b), viewed from the vertical direction Da. In this case, generation of the negative pressure to the lower side of the attraction belt 29a generates suction airflow from each suction hole toward the attraction belt 29a.
The group of sheet feed rollers 30 includes a pair of conveyance rollers (for example, conveyance rollers 30a and 30b). The pair of conveyance rollers, i.e., the conveyance rollers 30a and 30b in contact with each other rotate opposite to each other. By so doing, the sheet S that has reached the pair of conveyance rollers, that is, the conveyance rollers 30a and 30b, is conveyed toward the pair of registration rollers 7 (see
According to this configuration, for example, while the attraction belt 29a is moving, the negative pressure is generated to the lower side of the attraction belt 29a. During the above-described action, air is blown from the nozzle 28b to the sheet S1 at the sheet conveyance start position and the subsequent sheets S2 and the plurality of sheets S near the sheet S1. By so doing, the sheet S1 of the uppermost sheets of the plurality of sheets S contained in the sheet containing portion 15b (in other words, the sheet S1 functioning as a conveyance target) is separated from the other sheet S2 to float. Thus, the leading end side of the sheet S1 functioning as a conveyance target is attracted to the attraction belt 29a.
In this state, the attraction belt 29a is moved. With the movement of the attraction belt 29a, the sheet S1 functioning as a conveyance target is fed out toward the group of sheet feed rollers 30. Consequently, the leading end side of the sheet S1 functioning as a conveyance target reaches the pair of conveyance rollers (for example, the conveyance rollers 30a and 30b). At this time, the conveyance rollers 30a and 30b are rotated. As a result, the sheet S1 functioning as a conveyance target is conveyed to the image forming apparatus 3 via the pair of registration rollers 7 described above.
According to the present embodiment, the sheet feeding unit 6 includes the guides 21 to contact the surface of the sheet S1 functioning as a conveyance target over the area from the upstream region to the downstream region in the sheet conveyance direction Dc to guide the sheet S1. In this case, the sheet S1 functioning as a conveyance target is guided by the guides 21 while contacting over the given area from the upstream region to the downstream region of the sheet S1, viewed in the sheet conveyance direction Dc. With this configuration, the sheet S1 functioning as a conveyance target is restrained from floating as indicated by broken lines in
According to the present embodiment, it is preferable that the guides 21 contact the surface of the sheet S1 over an area from at least the upstream region of the sheet S1 in the sheet conveyance direction Dc to the center of the sheet S1 in the sheet conveyance direction Dc, so as to guide the sheet S1. With this configuration, the center of the sheet S1 that is easy to float by air blown from the air blowing device 28 is pressed down by the guides 21. As a result, the floating of the sheet S1 in the region from the trailing end of the sheet S1 including the center of the sheet S1 is restrained effectively.
According to the present embodiment, it is more preferable that the above-described given region is the downstream region (the leading end) of the sheet S1 in the sheet conveyance direction Dc. With this configuration, the guides 21 press down the substantially entire area in the sheet conveyance direction Dc of the sheet S1 that is about to float due to air blown by the air blowing device 28. As a result, floating of the sheet S1 is prevented more effectively.
According to the present embodiment, it is more preferable that the guides 21 are provided further from the trailing end (the end of the upstream side) of the sheet S1. Accordingly, curling of the trailing end of the sheet S1 is prevented.
According to the present embodiment, it is preferable that the guides 21 are parallel to the surface of the sheet S1 contained in the sheet containing portion 15b and parallel to the sheet conveyance direction Dc of the sheet S1. Accordingly, while maintaining the posture of the sheet S1 floating by air blown by the air blowing device 28, the sheet S1 is conveyed toward a downstream sheet conveyance passage (that is, the group of sheet feed rollers 30) without causing skew or other failure.
According to the present embodiment, the guides 21 are provided with functions capable of changing the position, such as the rotational motion 21r and the reciprocating motion 21m. In this case, in the rotational motion 21r of each of the guides 21, the sheet contact portion 21p rotates about the virtual axis 21f of the guides 21. Further, in the reciprocating motion 21m of each of the guides 21, the sheet contact portion 21p moves in the vertical direction Da. Consequently, the sheet S1 functioning as a conveyance target is separated from the subsequent sheets S2 by an optimal distance, so that the sheet S1 is held at a position to be conveyed easily and is positioned parallel in the sheet conveyance direction Dc. As a result, the sheet S1 separated by air is significantly enhanced in the conveyance accuracy and conveyance stability.
According to the present embodiment, the end fence 27 is mounted on the frame 20 (the reinforcement member 26). According to this configuration, both a process in which the end fence 27 is retreated from the sheet set opening 15a (the sheet containing portion 15b) and another process in which the sheet set opening 15a (the sheet containing portion 15b) is opened are performed simultaneously with a single rotation of the frame 20. As a result, the setting efficiency of the sheet S with respect to the sheet containing portion 15b is dramatically enhanced.
According to this embodiment, the upper end 23t side (the opening side) of the first receiving portions 23a and the second receiving portions 23b that support the guides 21 (the first hooks 21a and the second hooks 21b) is bent. In this case, the upper end 23t side (the opening side) is bent in a direction away from the hinges 22 (the second connecting portion 25b). By so doing, even when the frame 20 is rotated in order to open the sheet set opening 15a (the sheet containing portion 15b), the guides 21 (the first hooks 21a and the second hooks 21b) do not come off from the first receiving portions 23a and the second receiving portions 23b. As a result, the guides 21 are constantly supported by the frame 20 via the first receiving portions 23a and the second receiving portions 23b.
As illustrated in
The regulation members 31 are disposed at the first supports 24a and the second supports 24b described in the above-described embodiment. Each of the regulation members 31 is disposed at a position lower than the lower end 23e of the first receiving portions 23a and the second receiving portions 23b, projecting from the first receiving portions 23a of the first supports 24a and the second receiving portions 23b of the second supports 24b. In this case, the protruding direction is set in a direction along the sheet conveyance direction Dc. Further, as a protruding shape of the regulation members 31, for example, a three-dimensional shape such as a cylindrical shape or a rectangular shape is assumed. Here, as an example, a cylindrical regulation member is employed as the regulation members 31. The diameter of each of the regulation members 31 may be the same as or different from a recess width in the first receiving portions 23a and the second receiving portions 23b.
In the example illustrated in
As described above, according to Variation 1, the respective postures of the guides 21 supported by the frame 20 are restricted to a previously set inclination direction (the previously set inclination angle). In this case, when the sheet S1 functioning as a conveyance target is separated from the other sheet S2, the guides 21 rotate in the given direction (i.e., the previously set direction) while contacting the sheet S1. Accordingly, this configuration achieves the constant contact state between the guides 21 (the sheet contact portion 21p) and the sheet S1 functioning as a conveyance target. As a result, when separating the sheet S1 functioning as a conveyance target from the other sheets S2 (e.g., the subsequent sheets S2), air passes easily between the sheet S1 and the other sheets S2.
As illustrated in
In the exemplary configuration illustrated in
As described above, according to Variation 2, each of the guides 21 is supported by any of the plurality of receiving portions, i.e., the first receiving portions 23a and the second receiving portions 23b. Accordingly, the effect of restraint to lifting of the sheet S1 functioning as a conveyance target is performed at the maximum with the minimum number of guides 21. As a result, the sheet S is conveyed without causing a jam.
As illustrated in
Here, in the first method, for example, the guide 21 (for example, the sheet contact portion 21p) is increased in size or in diameter to increase the weight of the guide 21 or the guide 21 (for example, the sheet contact portion 21p) is decreased in size or in diameter to reduce the weight of the guide 21. In
In the second method, the weight 32 is attached to the guide 21. The weight 32 is attached to the guide 21 via an attachment 33. Here, it is preferable that various types of weights 32 with different weights are prepared according to the purpose of use and application. Further, it is preferable that the attachment 33 detachably attaches the weight 32 to the guide 21.
As described above, according to Variation 3, the weight of each of the guides 21 is changeable. Accordingly, the sheet S1 functioning as various types of conveyance targets from a lightweight, thin sheet S1 to a heavyweight, thick sheet S1 is stably conveyed.
Further, in the configuration of the above-described embodiment, the sheet feeding unit 6 is removed, together with the frame 20, from the sheet conveying device 1. However, the configuration of the sheet conveying device 1 is not limited to this configuration. For example, the following configuration of Variation 4 may be applied. In other words, in Variation 4, when the sheet feeding unit 6 is pulled out (removed) from the housing 1p of the sheet conveying device 1, the frame 20 remains in the housing 1p while supporting the guides 21.
As described above, according to Variation 4, the sheet feeding unit 6 does not include the frame 20 supporting the guides 21. In this case, the upper side of the sheet set opening 15a (the sheet containing portion 15b) is exposed. Accordingly, the plurality of sheets S is inserted to the sheet containing portion 15b through the sheet set opening 15a without rotating the frame 20. As a result, the setting efficiency of the sheet S with respect to the sheet containing portion 15b is enhanced.
As illustrated in
On the other hand, since the bearing 41 is fixed to the frame 20, the guides 21 do not move reciprocally in the vertical direction. Except the above-described structure, the configuration of the guide mechanism 16D according to Variation 5 is substantially identical to the guide mechanism 16 according to the present embodiment illustrated in
As described above, in the guide mechanism 16D according to Variation 5, the sheet S1 that functions as a conveyance target is separated from the subsequent sheet S2 by an optimal distance and is supported at a position from which the sheet S1 is easily conveyed. Simultaneously, the sheet S1 is positioned parallel to the sheet conveyance direction Dc. As a result, the sheet S1 separated by air is significantly enhanced in the conveyance accuracy and conveyance stability.
As illustrated in
On the other hand, since the slider 42 has a long shape extending along the first receiving portions 23a, the guides 21 do not perform the rotational motion 21r. Except the above-described structure, the configuration of the guide mechanism 16E according to Variation 6 is substantially identical to the guide mechanism 16 according to the present embodiment illustrated in
Similarly, as described above, in the guide mechanism 16E according to Variation 6, the sheet S1 that functions as a conveyance target is separated from the subsequent sheet S2 by an optimal distance and is supported at a position from which the sheet S1 is easily conveyed. Simultaneously, the sheet S1 is positioned parallel to the sheet conveyance direction Dc. As a result, the sheet S1 separated by air is significantly enhanced in the conveyance accuracy and conveyance stability.
The sheet conveying device 1 having a configuration of any one of the present embodiment and Variations 1 to 5 includes the sheet containing portion 15b, the air blowing device 28, the guides 21, and a support such as the frame 20. The sheet containing portion 15b contains the plurality of sheets including the single sheet S1 and the subsequent sheets S2. The air blowing device 28 blows air to the plurality of sheets to separate the single sheet S1 from the subsequent sheets S2. The guides 21 contacts the surface of the single sheet S1 separated from the subsequent sheets S2 to guide the single sheet S1. The support such as the frame 20 supports both ends of each of the guides 21 in the sheet conveyance direction Dc of the single sheet S1. Both ends of each of the guides 21 are movable with respect to the frame 20 by the reciprocating motion 21m in the direction of thickness of the single sheet S1 or by the rotational motion 21r about the virtual axis 21f that extends along the sheet conveyance direction Dc. When compared with a configuration in which either end of each of the guides 21 in the sheet conveyance direction Dc is rotatable or vertically movable to the frame 20, the guides 21 of the guide mechanisms 16, 16A, 16B, 16C, 16D, and 16E according to any one of the present embodiment and Variations 1 to 5 guide the single sheet S1 while the attitude of the sheet S1 is remained parallel along the sheet conveyance direction Dc. As a result, the sheet S1 separated by air is significantly enhanced in the conveyance accuracy and conveyance stability.
The effects described in the embodiments of this disclosure are listed as most preferable effects derived from this disclosure, and therefore are not intended to limit to the embodiments of this disclosure.
The embodiments described above are presented as an example to implement this disclosure. The embodiments described above are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, or changes can be made without departing from the gist of the invention. These embodiments and their variations are included in the scope and gist of the invention, and are included in the scope of the invention recited in the claims and its equivalent.
Number | Date | Country | Kind |
---|---|---|---|
2018-198560 | Oct 2018 | JP | national |
2019-188128 | Oct 2019 | JP | national |