Patent Application
20200102169
This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2018-185719 filed on Sep. 28, 2018, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
This disclosure relates to a sheet feeding device, an image forming apparatus incorporating the sheet feeding device, and an image forming system incorporating the sheet feeding device.
Various types of sheet feeding devices are known to include a first conveyor that conveys one conveyance target body from a bundle of conveyance target bodies loaded on a loading unit, a second conveyor that is disposed next to the first conveyor, and space below a sheet conveyance passage between the loading unit and the second conveyor.
At least one aspect of this disclosure provides a sheet feeding device including a sheet loader, a first conveyor, a second conveyor, and a guide. The sheet loader is configured to load a sheet bundle including a sheet with a flap. The first conveyor is configured to convey the sheet with the flap loaded on the sheet loader. The second conveyor is disposed adjacent to the first conveyor. The guide is disposed below the flap of the sheet to be conveyed, between the second conveyor and the sheet loader in a sheet conveying direction of the sheet. The guide is configured to guide the sheet.
Further, at least one aspect of this disclosure provides an image forming apparatus including an image forming device configured to form an image on a sheet, and the above-described sheet feeding device configured to feed the sheet toward the image forming device.
Further, at least one aspect of this disclosure provides an image forming system including an image forming apparatus configured to form an image at least on a sheet and the above-described sheet feeding device configured to feed the sheet toward the image forming apparatus.
The aforementioned and other aspects, features, and advantages of the present disclosure would be better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted.
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 feeding device, an image forming apparatus, 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 feeding device, image forming apparatus, and image forming system, and is implemented in the most effective manner in an electrophotographic image forming apparatus.
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, embodiments of the present disclosure are described below. In the drawings for explaining the following embodiments, the same reference codes are allocated to elements (members or components) having the same function or shape and redundant descriptions thereof are omitted below.
A description is given of a sheet feeding device according to an embodiment of this disclosure.
As illustrated in
The sheet feeding device 200 is disposed at a side face of an apparatus body of the image forming apparatus 100.
The recording method of the image forming apparatus 100 to which the sheet feeding device 200 according to the present embodiment is applied is not particularly limited, and any method such as an electrophotographic method or an inkjet method is adopted. A sheet entrance is provided on the right side of the apparatus body of the image forming apparatus 100 in
As illustrated in
The term “sheet” includes plain paper, coated paper, label paper, OHP sheet, film, and prepreg. Prepregs are mainly used as materials for laminates and multilayer printed wiring boards. For example, the prepreg includes a sheet-like material that is manufactured by, for example, continuously impregnating a resin varnish mainly formed by a thermosetting resin such as epoxy resin and polyimide resin, into an elongated base such as glass cloth, paper, non-woven cloth, and aramid cloth, then heating, drying, and cutting. The sheet includes an envelope or bag-like medium provided with a flap for closing the mouth of the envelope or bag-like medium.
A sheet feeding unit 20 is disposed above the corresponding sheet tray 10. The sheet feeding unit 20 separates and feeds a sheet loaded on the sheet tray 10. The sheet feeding unit 20 includes an attraction belt 21 that functions as a first conveyor and a sheet conveying body, and an upward air suction device 23.
Each sheet loaded on the lower sheet tray 10 passes through a lower conveyance passage 82 to be conveyed by the pair of ejection rollers 80 to the apparatus body of the image forming apparatus 100. Similarly, each sheet loaded on the upper sheet tray 10 passes through an upper conveyance passage 81 to be conveyed by the pair of ejection rollers 80 to the apparatus body of the image forming apparatus 100.
As illustrated in
Further, each of the upper sheet tray 10 and the lower sheet tray 10 includes an air blowing device 24 and a downward air suction device 25. The air blowing device 24 functions as an air blowing device to blow air to the upper sheets of the sheet bundle P. The downward air suction device 25 functions as an air suction device to draw (intake) air near the upper sheets of the sheet bundle P.
The air blowing device 24 that functions as an air blower includes a front air blowing device 26 and side air blowing devices 27. As illustrated in
Blowing fans are disposed in the floating air chamber 31a and the separation air chamber 31b, respectively, to send air. The air blown from the floating nozzle 26a in a direction indicated by arrow a1 in
Further, as illustrated in
Each of the side air blowing devices 27 includes side floating nozzle front portions 27a and side floating nozzle rear portions 27b. The side floating nozzle front portions 27a are arranged to face front sides of lateral sides of the sheet in the sheet conveying direction and guide air in a direction to separate and float the sheet bundle P. The side floating nozzle rear portions 27b are arranged to face rear sides of the lateral sides of the sheet in the sheet conveying direction. Air blown from the side floating nozzle front portions 27a and the side floating nozzle rear portions 27b is referred to as side floating air. The side floating air is discharged from an air discharging port provided to a portion that faces the upper part of the sheet bundle P of each of the side fences 28 and is blown to the side face of the upper part of the sheet bundle P. The air blown from the floating nozzle 26a and the separation nozzle 26b of the front air blowing device 26 and the side floating nozzle front portion 27a and the side floating nozzle rear portion 27b of the side air blowing devices 27 lifts the sheets of the upper part of the sheet bundle P. Further, as illustrated in
As illustrated in
As illustrated in
In the sheet feeding device 200, the distance between the upper face of the uppermost sheet of the sheet bundle P in the sheet tray, in which the number of sheets decreases with sheet feeding, and the lower face of the attraction belt 21 is kept within a certain range. Hence, the sheet feeding device 200 detects the height of the upper face of the uppermost sheet with the sheet top sensor 41, and controls, based on a detection signal of the sheet top sensor 41, a bottom-plate lift motor as a drive source of a lift to vertically move the bottom plate of the sheet tray. Such a configuration can control the height of the bottom plate so that the distance between the upper face of the uppermost sheet of the sheet bundle P placed on the bottom plate and the bottom face of the attraction belt 21 falls within a certain range.
Further, the accuracy of the stop position in the height direction of the sheet loading table 11 detected by the sheet top sensor 41 is enhanced for the following reason (see
The downward air suction device 25 includes a downward air suction nozzle 25a that draws air around the leading end of the sheets of the upper part of the sheet bundle P so that a negative pressure generated by the downward air suction fan 42 is applied to the area around the leading end of the sheets of the upper part of the sheet bundle P. Two of the downward air suction nozzles 25a are arranged between the floating nozzle 26a and the separation nozzle 26b.
Further, the projecting end of the downward air suction nozzle 25a is disposed to suck the uppermost sheet of the sheet bundle P at a position close to the uppermost sheet in the height direction. Accordingly, it is more effective to reduce the gap between the downward air suction nozzle 25a and the attraction belt 21 since the separation effect is enhanced when the downward air suction nozzles 25a suck the uppermost sheet at positions closer to the uppermost sheet of the sheet bundle P. However, since a gap through which the uppermost sheet of the sheet bundle P can pass is also provided, the gap is preferably about 1 mm to about 3 mm. The gap is adjusted by the height of the downward air suction nozzle 25a with a mounting screw as adjuster. In addition, since the side faces and the upper face of the projecting end of the downward air suction nozzle 25a contacts a sheet, which may be worn and deteriorate. Hence, surface treatment or processing, such as metal plating, to reduce abrasion may be performed on the side faces and the upper face of the projecting end of the downward air suction nozzle 25a, thus allowing extension of the product life.
In the suction with the downward air suction nozzles 25a, a solenoid 36 reciprocally moves a pulling shaft in directions, thus switching opening and shutting of the downward air suction shutter. The downward air suction shutter is coupled to the solenoid 36 via the pulling shaft. A controller 60 controls turn-on and -off of the solenoid 36 to switch shutting-off and opening of suction air in the downward air suction chamber 33.
The floating nozzle 26a and the separation nozzle 26b of the front air blowing device 26 and the downward air suction nozzle 25a of the downward air suction device 25 perform air blowing and suction from a notch formed in an inclined plate portion 50a which is inclined and extended so as to move up from the upper end of a front-alignment fence 50, which functions as an aligner to align the trailing end of the sheet bundle P loaded on the sheet loading table 11 toward the downstream side of the sheet conveying direction, as illustrated in
In the space 51 above the inclined plate portion 50a, as illustrated in
The space 51 below the sheet conveyance passage illustrated in
A detailed description is given of the above-described configuration having the space 51.
In
In a case in which the flap Pla is folded downward, when the envelope P1 is further fed from the state in which the front end of the envelope P1 having the folding origin P1b of the flap P1a is beyond the front-alignment fence 50, as illustrated in
If the flap P1a is lowered in the space 51, the flap P1a may contact the upper face of the inclined plate portion 50a, resulting in paper jam. It is likely that envelopes and media are damaged or broken. In particular, in the present embodiment, the tip of the downward air suction nozzle 25a, the sensor holder 52a, and the sensor cover plate 50c are extended into the space 51. Accordingly, the flap P1a that has been lowered comes into contact with the tip of the downward air suction nozzle 25a, the sensor holder 52a, and the sensor cover plate 50c, which is likely to generate paper jam easily.
In order to address this inconvenience, it is conceivable to load the envelopes and media onto the sheet loading table 11 with the flaps of the envelopes and media being open, or to open the folded flaps of the sheets before the envelopes are loaded on the sheet loading table 11 and close the open flaps of the envelopes after the printing job performed by the image forming apparatus. However, these operations are not efficient in work efficiency and low in productivity. It has been found that, even when the envelopes are loaded with the flaps P1a facing down, if the envelopes are loaded on the sheet loading table 11 while the folding line is in a posture orthogonal to the sheet conveying direction, clogging due to the lowering of the flap P1a is relatively less likely to occur. However, in a case in which the length of the side of the envelope in the sheet conveying direction with this posture is less than the length of a conveyable envelope or medium in the sheet conveying direction in the image forming apparatus 100 or the sheet feeding device 200, the envelope is not conveyed in such a posture.
For example, in a case of the sheet feeding device 200 according to the present embodiment, even though a sheet having a length of less than 148 mm in the sheet conveying direction is not conveyable, there is a demand for printing on a rectangular envelope or medium having a short side of 130 mm and a long side of 180 mm to 200 mm, with a flap P1a to be folded at a folding line along the long side, as illustrated in
As the short side of the envelope or medium is shorter, the flap P1a of the envelope or medium is closer to the center of the short side and, as illustrated in
Therefore, in the present embodiment, a guide 55 is provided in order to address the above-described inconveniences. As described above,
In order to prevent the lowering of the flap P1a, it is desirable that a width direction end 55R of the guide face illustrated in
Since the lower face of the attraction belt 21 that functions as an opposing body is disposed facing the upper face of the guide 55, the following effect is achieved. Specifically, by sandwiching the flap P1a between the upper face of the guide 55 and the lower face of the attraction belt 21, the fold of the flap P1a is strengthened and the flap P1a is made more difficult to lower. Once the folding is strengthened, the envelope or medium maintains the posture without the support by the upper face of the guide 55 in the entire region of the space 51 in the sheet conveying direction. Strengthening the folding is sufficient in a closed state to a degree in which an envelope or medium is conveyable, and includes a case in which the envelope or medium returns to an open and closed state before the guide 55 is provided when the guide 55 is not supporting the envelope or medium.
It is desirable that the upper face of the guide 55 and the lower face of the opposing body (i.e., the attraction belt 21) are disposed in parallel to a direction orthogonal to the sheet conveying direction in order to strengthen the fold by the opposing body (i.e., the attraction belt 21) and the upper end portion of the guide 55 as described above. In addition, it is effective that the width direction end 55R of the guide face of the guide 55 is located outside the folding line of the flap P1a (i.e., the side on the folding line of the envelope P1) in order to strengthen the folding preferably. The tip edge of the flap P1a is inclined so as to be closer to the upstream side of the sheet conveying direction toward the center of the width direction center at an angle θ, as illustrated in
Different from this configuration, in a case in which the tip edge of the flap P1a is orthogonal to the sheet conveying direction, it is highly likely that, when entering the gap between the upper face of the guide 55 and the lower face of the opposing body (i.e., the attraction belt 21), a portion at the center in the width direction, which is relatively easy to open in the tip edge, collides with the guide 55 first, and the flap is deformed so as to open in the portion.
For example, the guide 55 illustrated in
The guide 55 is detachably attached on the inclined plate portion 50a of the front-alignment fence 50 on the right side of the center reference line C when viewed from the upstream side of the sheet conveying direction, as illustrated in
The oblique ceiling plate 55d of the guide 55 functions as a blocker to cover the floating nozzle 26a on the right side of the center reference line C to block air from the floating nozzle 26a. An inserting projection 55e that is inserted into the opening of the floating nozzle 26a is formed on the lower face side of the oblique ceiling plate 55d, as illustrated in
The guide 55 is positioned by inserting the inserting projection 55e into the opening of the floating nozzle 26a of the inclined plate portion 50a on the right side of the center reference line C, and is attached by attracting the guide 55 to the inclined plate portion 50a made of metal by a magnetic force of the magnet 55h provided on the bottom plate 55f. In the state in which the guide 55 is attached to the inclined plate portion 50a, the guide 55 is positioned as illustrated in
The guide 55 in this example is attached by the magnetic force of the magnet 55h and is removed against the magnetic force. Therefore, in a case in which an envelope in a flap folding state which is likely to be jammed by the lowering of the flap P1a is fed, the guide 55 is attached onto the inclined plate portion 50a. By contrast, in a case in which an envelope in the flap folding state is not fed, the guide 55 is removed from the inclined plate portion 50a. If the guide 55 is attached to the inclined plate portion 50a when feeding plain sheets or other general sheets, forming the space 51 such as the anti-curling, which is the original aim, is not achieved, and therefore, attaching or removing the guide 55 relative to the inclined plate portion 50a is to prevent jam from causing due to the contact of the curled portion with the guide 55 in some cases.
Furthermore, as illustrated in
The guide 55 may be modified, as a variation, by removing the hatched portion of the front plate in
In the above example, the loading posture is for loading an envelope on the sheet loading table 11 in which the folding line of the flap P1a is located on the right side of the center reference line C. However, when the sheet is loaded on the sheet loading table 11 and fed such that the posture is rotated by 180 degrees and the folding line of the flap P1a is located on the left side of the center reference line C, a plurality of guides 55 is detachably attached at positions different from each other, in other words, at two or more positions set to be symmetrical on both the right and left sides with respect to the center reference line C (a center reference position) in accordance with the position of the flap P1a.
Thus, the plurality of guides 55 may be prepared to be symmetrical, and the plurality of guides 55 alone may be attached, and may remain attached on both of the right and left sides as long as no inconvenience occurs. Moreover, the plurality of guides 55 symmetrical on the right and left sides may be connected to each other as a single unit. In a case in which both the plurality of guides 55 symmetrical on the right and left sides are attached, a guide 58 may be symmetrical to the guide 55 in
Instead of removing the guide 55 so as not to get in the way when feeding a general sheet, the guide may be changed between a state in which the upper face of the guide 55 faces the flap P1a in the part in the width of the sheet conveyance passage and a state in which the upper face of the guide 55 does not face the flap P1a in the part in the width of the sheet conveyance passage. The shape of the guide may be deformed or, as illustrated in
As illustrated in
A host controller of the image forming apparatus 100 receives an image forming instruction associated with the sheets set in the sheet trays 10 of the sheet feeding device 200 via a control panel of the image forming apparatus 100. Then, the host controller transmits a feeding instruction and information, such as the type of the sheet loaded on the sheet loading table 11 of the sheet trays 10, to the controller 60 of the sheet feeding device 200 (see
Next, the controller 60 causes the blowing fans of the side floating air, the front floating air, and the separation air, the belt attraction fan of the upward suction air, and the downward suction fan of the downward suction air to operate. Then, the controller 60 executes a preliminary separating operation for 5 seconds (step S2). In the present embodiment, the preliminary separating operation is executed for 5 seconds. It is to be noted that the time of the preliminary separating operation is not limited to 5 seconds and may be appropriately set according to the configuration of the sheet feeding device.
During the preliminary separating operation, the side floating air shutter and the front floating air shutter are opened. Accordingly, the side floating air and the front floating air are blown to the lateral sides and the front side of the upper portion of the sheet bundle P. Thus, the first sheet being the uppermost sheet and several sheets of the second and subsequent sheets float among sheets in the upper portion of the sheet bundle P. In the preliminary separating operation, since the separation air shutter is also opened, the first sheet is separated from the second and subsequent sheets by the separation air. Further, in the preliminary separating operation, the upward suction air shutter is also opened, thus causing the floated first sheet to be attracted to the attraction belt 21.
When the preliminary separating operation is terminated (after 5 seconds have passed from the start of the operation of each fan), the attraction belt 21 is rotated to feed the first sheet. At this time, if the second sheet excessively floats or disturbs the behavior and contacts the first sheet, the second sheet might be conveyed from the sheet bundle P together with the first sheet. Hence, when the preliminary separating operation is completed, the front floating air shutter and the separation air shutter are closed to drop the floated second sheet so as not to contact the first sheet, thus restraining the multifeeding (step S3). Further, the downward suction air shutter is opened to start downward suction (step S4). The downward suction air shutter is closed until the preliminary separating operation is completed. Thus, in the preliminary separating operation, the first sheet is favorably attracted to the attraction belt 21 without being disturbed by the downward suction air. Then, a feed motor is started to rotate the attraction belt 21 on which the first sheet is attracted, thus starting sheet feeding (step S5).
When a predetermined time has passed from the start of feeding (when the leading end of the first sheet is fed to a predetermined subsequent step (for example, a pair of conveying rollers) downstream from the attraction belt 21, the upward suction air shutter is closed to release the first sheet attracted on the attraction belt 21 (step S6). Further, driving of the feeding motor is stopped to stop the attraction belt 21 (step S7).
Next, the controller 60 determines whether there is a sheet to be fed (step S8). When there is a subsequent sheet to be fed (YES in step S8), the controller 60 causes the front floating air shutter to open to resume the blowing of the front floating air toward the front side of the upper portion of the sheet bundle P. The controller 60 also causes the separation air shutter to open and resumes the blowing of the separation air (step S9).
Next, the controller 60 closes the downward suction air shutter and prevents the floating of the second sheet to be fed subsequently from being disturbed by the downward suction air (step S10). The controller 60 opens the upward suction fan shutter to resume the attraction of the sheet to the attraction belt 21 (step S11). Thus, the second sheet can be favorably attracted to the attraction belt. Then, the process from steps S3 to S8 is performed to feed the sheet.
In step S8, steps S3 to S11 are repeated until the number of sheets fed reaches a set number. If the number of sheets fed reaches the set number and there is no subsequent sheet to be fed (NO in step S8), the controller 60 causes, in step S12, each shutter to be set in the initial state, stops the operation of each fan, and terminates the feeding operation.
The sheet feeding device 200 in the above embodiment uses the attraction belt 21 and the air blowing device 24 as illustrated in
As illustrated in
Since the space 51 is generated between the upper face of the inclined plate portion 50a and the sheet conveyance passage, as similar to the sheet feeding device 200 of the above-described embodiment, when the sheet is fed while being loaded on the sheet loading table 11 in a posture in which the flap P1a of the envelope P1 is folded, in which the folding line direction is parallel to the sheet conveying direction, and in which the flap P1a is in the lower side, the flap P1a may lower in the space 51 to contact with the inclined plate portion 50a to cause jam. Therefore, in order to address this inconvenience, as illustrated in
As illustrated in
The guide 75 illustrated in
It is to be noted that, in the above-described embodiments and variations, the method of detaching and attaching the guide 55 and other members may be performed by mechanical engagement, for example, screwing, in addition to using magnetic force. The material of the guide 55 is not particularly limited to the above-described embodiments and variations. For example, the guide 55 may be made of metal or resin.
Further, although the above-described embodiments and variations describe that this disclosure is applied to the image forming system 1 including the image forming apparatus 100 and the sheet feeding device 200 but this disclosure is not limited thereto. For example, this disclosure may be applied to a sheet feeding device (for example, the sheet feeding device 200) provided in the image forming apparatus 100.
Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that, within the scope of the above teachings, the present disclosure may be practiced otherwise than as specifically described herein. With some embodiments having thus been described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the present disclosure and appended claims, and all such modifications are intended to be included within the scope of the present disclosure and appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-185719 | Sep 2018 | JP | national |
