JP2019172449A - Sheet feeding device - Google Patents

Abstract

To surely separate a top sheet from subsequent sheets when sucking and conveying the top sheet floated by an airflow blown from a side to a top of stacked sheets.SOLUTION: Among sheets P stacked on a sheet feeding table 21, an uppermost plurality of sheets P are floated from a position where the sheets are stacked, by a jet of air ejected from a floating air ejection port 24 to a floating upper limit position brought into contact with a floating restriction plate 27. The jet of air blown from a pressure air ejection port 25 is blown to a side end portion of the sheets P that have floated to the floating upper limit position, and due to this high-pressure jet, the sheets P that have floated to the floating upper limit position are bent by the floating restriction plate 27 so that a central portion is positioned below a side end portion. Then, only an uppermost sheet P is corrected for bending by suction from above by a suction conveyance unit 12, and a sheet is separated from the second and subsequent sheets P at the floating upper limit position and sucked by the suction conveyance unit 12.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sheet feeding apparatus that feeds the stacked uppermost sheets one by one.

  For example, there is known a paper feeding device that sucks the uppermost sheets stacked on a paper feeding table one by one by a suction conveyance device and sends them to an image forming apparatus. In this type of paper feeding device, if the next paper is caught in the cutting burr generated on the edge of the paper or the papers are brought into close contact with each other due to static electricity, a plurality of papers are overlapped to the image forming apparatus and jammed. Cause it.

  Therefore, it is known that air is blown from the side to the uppermost part of the stacked sheets of paper, and the two sheets are separated by flowing air between the uppermost sheet and the next sheet.

  However, when the paper is curled, especially when the leading edge of the paper feed tray is curled upward, not only the top paper but also the next paper is lifted and sucked together. End up.

  Therefore, the uppermost sheet that floats on the slope of the ascending restriction member provided on the abutting wall on the leading side in the transport direction of the sheet feed table is brought into contact with the upper sheet and bent upward, so that it can be separated from the next sheet. Has been proposed (for example, Patent Document 1).

JP 2012-131614 A

  However, if the top sheet is bent upward, a large space is created between the top sheet and the next sheet, creating a negative pressure. When the next sheet is sucked after the suction conveyance, there is a possibility that the next sheet is further sucked together and double-fed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to suck and convey the uppermost sheet floated by the air flow blown from the side to the uppermost part of the stacked sheets. Another object of the present invention is to provide a sheet feeding apparatus that can reliably separate the uppermost sheet from the following sheets.

In order to achieve the above object, a sheet feeding apparatus according to an aspect of the present invention includes:
A first jet port that blows air to the side of the uppermost part of the stacked sheets and jets air that floats the plurality of uppermost sheets and regulates the descent;
A levitation regulating unit that regulates the levitation of the sheet by the air ejected from the first ejection port at the levitation upper limit position;
Blowing the side of the sheet at the upper limit position of levitation by spraying it to the side of the upper limit position of the levitation, which is restricted from moving in the vertical direction by the air ejected from the first ejection port and the levitation restriction unit, A second jet port for jetting air that presses against the center side of the sheet and deflects the sheet;
A suction conveyance unit for sucking the sheet from above the floating upper limit position and conveying the sheet adsorbed by the suction;
Blowing the leading end portion of the sheet at the floating upper limit position in the conveying direction by the suction conveying portion, the center portion of the sheet is positioned below the side end portion in the bending direction of the second sheet from the floating upper limit position. A third jet outlet that ejects air that separates the first sheet from the second sheet from the levitation upper limit position,
Is provided.

  According to the present invention, when the uppermost sheet floated by the air flow blown from the side to the uppermost part of the stacked sheets is sucked and conveyed, the uppermost sheet is moved from the next sheet onward. It can be reliably separated.

1 is an explanatory diagram showing a schematic configuration of a main part of an ink jet recording apparatus equipped with a paper feeding device according to an embodiment of the present invention. It is a perspective view which shows schematic structure of the paper feeding apparatus which concerns on one Embodiment of this invention applied to the external paper feeding stand of FIG. It is explanatory drawing which shows typically the structure of the floating unit of FIG. 2 seeing from the printing part side of the inkjet recording device of FIG. FIG. 4 is a graph showing a relationship between a pressing amount of a side end portion of a sheet toward a central portion side and a downward pressing amount of the central portion of the sheet due to air ejected from a pressing air outlet of FIG. 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals.

  The following embodiment exemplifies an apparatus or the like for embodying the technical idea of the present invention. The technical idea of the present invention is based on the material, shape, structure, arrangement, etc. of each component. It is not specified to the following. The technical idea of the present invention can be variously modified within the scope of the claims.

  FIG. 1 is an explanatory diagram showing a schematic configuration of a main part of an ink jet recording apparatus equipped with a paper feeding device according to an embodiment of the present invention. The ink jet recording apparatus shown in FIG. 1 is an ink jet line color printer.

  In the following description, the direction orthogonal to the paper surface of FIG. 1 is the left-right direction, and the surface direction of the paper surface is the right side. Also, the top and bottom of the paper surface in FIG. 1 is the vertical direction, and the horizontal direction of the paper surface in FIG. The right direction on the paper is the front and the left direction is the rear. Further, the path indicated by the thick line in FIG. 1 is a transport path R along which the paper P, which is a print medium, is transported. In the following description, upstream and downstream mean upstream and downstream in the transport path R, respectively.

  As shown in FIG. 1, the ink jet recording apparatus 1 of the present embodiment includes a paper feeding unit 2, a printing unit 3, a control unit 9, and an operation panel 10.

  The paper feeding unit 2 feeds the paper P (corresponding to a sheet in the claims) to the printing unit 3. The paper feed unit 2 includes an external paper feed unit 11, a suction conveyance unit 12, a plurality of internal paper feed trays 13, a plurality of pairs of internal paper feed rollers 14, a plurality of pairs of internal paper feed conveyance rollers 15, and a resist. And a roller 16.

  The external paper feeding unit 11 is a unit on which paper P used for printing is stacked on the paper feeding table 21. The external paper feeding unit 11 is partly exposed outside the casing (not shown) of the inkjet recording apparatus 1.

  The suction conveyance unit 12 takes out the sheets P one by one from the external sheet feeding unit 11 and conveys the sheets P along the conveyance path R toward the registration rollers 16. The suction conveyance unit 12 sucks the central portion in the width direction of the paper P by the air sucked from the suction hole 12b (see FIG. 2) of the belt 12a that is rotationally driven by a motor (not shown). Then, the sucked paper P is transported toward the front transport path R along the circumferential direction of the belt 12a.

  The internal paper feed tray 13 is for loading paper P used for printing. The internal paper feed tray 13 is disposed inside a casing (not shown) of the inkjet recording apparatus 1.

  The internal paper feed roller 14 takes out the paper P one by one from the internal paper feed tray 13 and sends it out to the transport path R. The internal paper feed roller 14 is rotationally driven by a motor (not shown).

  The internal paper feed conveyance roller 15 conveys the paper P taken out from the internal paper feed tray 13 toward the registration roller 16. The internal paper feeding / conveying roller 15 is disposed along a conveyance path R between the internal paper feeding roller 14 and the registration roller 16. The internal paper feed roller 15 is rotationally driven by a motor (not shown).

  The registration roller 16 temporarily stops the paper P transported from the suction transport unit 12 or the internal paper feed transport roller 15 and then transports the paper P toward the printing unit 3. The registration roller 16 is disposed on the downstream side of the suction conveyance unit 12 and the internal paper feed conveyance roller 15. The registration roller 16 is rotationally driven by a motor (not shown).

  The printing unit 3 includes a belt platen unit 3a and four inkjet heads 4A to 4D corresponding to the colors CKMY.

  The belt platen unit 3a conveys the sheet P fed from the sheet feeding unit 2 while holding it on the belt. The belt platen portion 3 a is disposed on the downstream side of the registration roller 16.

  Each of the inkjet heads 4A to 4D prints an image by ejecting ink of each color corresponding to the paper P conveyed by the belt platen unit 3a. The inkjet heads 4A to 4D are disposed above the belt platen portion 3a.

  Each of the inkjet heads 4 </ b> A to 4 </ b> D is configured to be movable in the vertical direction by the head gap adjustment unit 6. The head gap adjustment unit 6 moves the inkjet heads 4A to 4D up and down, thereby adjusting the interval (head gap) between the inkjet heads 4A to 4D and the paper P conveyed by the belt platen unit 3a.

  Below the inkjet heads 4A to 4D, cleaning devices 5A to 5D are provided corresponding to the inkjet heads 4A to 4D. Each of the cleaning devices 5A to 5D receives ink discharged by the purge operation of each inkjet head 4A to 4D for cleaning.

  The cleaning devices 5A to 5D wipe the remaining ink discharged from the inkjet heads 4A to 4D from the nozzle surfaces of the inkjet heads 4A to 4D by the purge operation.

  The printing unit 3 may be based on a method other than the inkjet method, such as an electrophotographic method, a thermal head method, a stencil printing method, or the like.

  An external print job is input to the control unit 9. An operation panel 10 is connected to the control unit 9. On the operation panel 10, various types of information relating to printing, for example, specifications of paper P stacked on the external paper feed unit 11 or the internal paper feed tray 13 of the paper feed unit 2 (paper size, paper type, etc.) are provided. And the environment information (temperature, humidity, etc.) of the installation location of the inkjet recording apparatus 1 are input by the user.

  Based on the print setting information of the input print job and the information input from the operation panel 10, the control unit 9 supplies the paper P of the external paper feed unit 11 and the internal paper feed tray 13 to the print unit 3. The image is printed on the paper P.

  Next, a schematic configuration of a paper feeding device according to an embodiment of the present invention applied to the external paper feeding unit 11 will be described with reference to a perspective view of FIG.

  FIG. 2 is a perspective view showing a schematic configuration of a paper feeding device 20 (corresponding to a sheet feeding device in claims) of this embodiment applied to the external paper feeding unit 11 of FIG.

  2 shows a perspective view of the paper feeding device 20 viewed from the side of the paper P. FIG. The end face of the paper P shown obliquely in FIG. 2 is the front end face of the paper P located on the main body side (printing unit 3 side) of the inkjet recording apparatus 1 of FIG.

  At the top of the paper P stacked on the paper feed tray 21 of the paper feeding device 20, the horizontal floating air indicated by the arrow A in FIG. Diagonally upward separating air is blown. The floating air A floats on the front end surface side of the plurality of sheets P at the top of the paper feed table 21, and the separation air B separates the front end surface side of the plurality of sheets P that floated. To provide a space above and below.

  However, when the paper P is curled, particularly when the leading edge of the paper P is curled upward, the top paper P and the second paper P are separated together and remain overlapped. It will be adsorbed by the suction conveyance unit 12. Then, the two sheets of paper P are double-fed to the conveyance path R by the suction conveyance unit 12, causing a conveyance abnormality such as a jam on the conveyance path R.

  Therefore, in the present embodiment, the paper feeding device 20 is provided with a configuration for preventing the double feeding of the paper P. The paper feeding device 20 has a paper feeding base 21 for the paper P shown in FIG. 1 and a pair of floating units 22 and 22 for preventing the paper P from being double-fed.

  The paper feed table 21 is moved up and down by a lifting unit (not shown) according to the increase or decrease of the stacked paper P. The position of the uppermost sheet P stacked on the sheet feed table 21 is maintained at a height at which the belt 12a of the suction conveyance unit 12 can be sucked by moving the sheet feed table 21 up and down by the lifting unit.

  Each floating unit 22 is erected on both the left and right ends on the leading end side of the paper P loaded on the paper feed table 21. Each floating unit 22 can be configured to be movable in the left-right direction with respect to the paper feed table 21 according to the size (paper width) of the paper P in the width direction.

  FIG. 3 is an explanatory view schematically showing the structure of each levitation unit 22. FIG. 3 shows a state in which each floating unit 22 is viewed from the printing unit 3 side of the inkjet recording apparatus 1 of FIG. 1, that is, from the downstream side in the conveyance direction of the paper P by the suction conveyance unit 12.

  Note that a duct member 17 and a duct member 18 are arranged on the front side of the paper P of the paper feed table 21 on the paper surface of FIG. Each of the duct members 17 and 18 has a floating air outlet 17a and a separation air outlet 18a (corresponding to a third outlet in the claims) opened on the front end side of the paper P of the paper feed base 21. .

  The floating air outlet 17 a horizontally ejects the above-described floating air A toward the front end of the uppermost sheet P of the sheet feed table 21. The separation air ejection port 18 a ejects the separation air B described above obliquely upward toward the front end of the uppermost sheet P of the sheet feed table 21.

  Each levitation unit 22 includes a duct member 23, a levitation air ejection port 24 and a pressing air ejection port 25, a guide plate 26, and a levitation restriction plate 27.

  The duct member 23 has two air flow paths 28 and 29 inside. Each air flow path 28, 29 accommodates a fan 28a, 29a for blowing. The fans 28a and 29a can adjust the air flow rate. The fan 29a blows air having a larger air volume than the fan 28a.

  The floating air outlet 24 (corresponding to a first outlet in the claims) is formed on the inner surface of the duct member 23. The inner side surface of the duct member 23 is a surface facing the left and right side surfaces in the width direction of the paper P. The floating air outlet 24 is disposed at a location facing the side surface of the uppermost sheet P loaded on the sheet feed table 21.

  The floating air outlet 24 communicates with the air flow path 28 of the duct member 23. The floating air outlet 24 jets the floating air blown to the air flow path 28 by the fan 28 a to the uppermost side of the paper P loaded on the paper feed table 21.

  The pressed air outlet 25 (corresponding to the second outlet in the claims) is formed on the inner surface of the duct member 23 and is disposed above the floating air outlet 24 adjacent to the floating air outlet 24. ing.

  The pressed air outlet 25 communicates with the air flow path 29 of the duct member 23. The pressure air outlet 25 ejects the pressing air blown by the fan 29a to the air flow path 29 above the floating air ejected from the floating air outlet 24 with a higher air volume than the floating air. To do.

  The guide plate 26 is disposed close to the side surface of the paper P except for the uppermost part of the paper feed table 21. The guide plate 26 regulates the movement of the paper P on the paper feed table 21 in the left-right direction.

  The floating restriction plate 27 (equivalent to a bending restriction portion and a floating restriction member in claims) is attached to the topmost portion of the duct member 23. The leading end of the flying regulation plate 27 extends horizontally from the duct member 23 toward the paper P and is disposed above both side edges of the uppermost paper P of the paper feed table 21.

  The levitation restriction plate 27 causes the uppermost sheet P of the sheet feed table 21 to float by the air ejected from the levitation air outlet 24 from the belt 12a of the suction conveyance unit 12 at both end portions on the leading end side of the sheet P. Is also regulated at the lower levitation upper limit position. The floating restriction plate 27 is disposed at a position that does not interfere with the suction operation of the central portion in the width direction of the paper P by the suction conveyance unit 12.

  In the sheet feeding device 20 of the present embodiment configured as described above, the uppermost plurality of sheets P among the sheets P stacked on the sheet feeding table 21 are generated by a jet of air ejected from the floating air ejection port 24. Ascend from the loaded position. The floating of the paper P is physically restricted by the both end portions on the leading end side of the topmost paper P that has floated coming into contact with the floating restriction plate 27. That is, the position of the flying restriction plate 27 is the upper limit position (floating upper limit position) of the sheet P.

  Further, the plurality of sheets of paper P that have floated and become a bundle are restrained at the upper limit of the floating position by the jet of air ejected from the floating air ejection port 24. In other words, the sheet P that has floated to the floating upper limit position is sandwiched between the floating restriction plate 27 and the air from the floating air outlet 24 and is restricted from moving in the vertical direction.

  Further, a jet of air blown out from the compressed air outlet 25 is blown onto the side end portion of the paper P that has floated to the floating upper limit position. At this time, the jet of air from the pressure air outlet 25 is surrounded by the side end surface of the paper P that has floated to the upper limit position of the flying, the floating restriction plate 27, and the jet of air that has been jetted from the floating air outlet 24. It stays in the space S. For this reason, the space S has a higher pressure than the surroundings.

  Therefore, the paper P at the upper limit of the flying position to which the air from the pressure air outlet 25 is blown is deflected by pressing the side end portion toward the center side. Here, on the leading end side of the sheet P at the floating upper limit position, the air B for separation is blown obliquely upward from the separation air outlet 18 a of the duct member 18. The separation air B separates the sheets P with the floating upper limit position overlapped, and the separation air B wraps around the gap formed between the sheets P.

  The separation air B that has entered the gaps between the sheets P is reflected by the lower surface of each sheet P at the floating upper limit position, and is blown onto the upper surfaces of the second and subsequent sheets P. For this reason, the bending direction of the second and subsequent sheets of paper P bent by the air from the compressed air outlet 25 is downward.

  On the other hand, the uppermost sheet P wraps around the gap with the second sheet P and is pushed upward by the diagonally upward separating air B blown to the lower surface of the uppermost sheet P. The air is flatly developed against the pressing force from the side end portion to the center side by air from the air. As a result, the uppermost sheet P at the floating upper limit position is held at the floating upper limit position in a flat posture and separated from the second sheet P that bends downward.

  FIG. 4 is a graph showing the relationship between the pressing amount of the side edge of the paper P toward the center by the air blown from the pressing air outlet 25 and the amount by which the central portion of the paper P is pushed downward. As shown in this graph, when the side end of the paper P is pushed toward the center by the air blown from the compressed air outlet 25, the larger the amount of pushing, the larger the amount, and the center of the paper P is pushed downward. It is done.

  For this reason, two sheets excluding the uppermost sheet P are pressed by pressing the side end portions of the plurality of sheets P that have floated to the floating upper limit position by the air blown from the pressing air outlet 25. The paper P after the eye can be bent downward and reliably separated from the uppermost paper P.

  When the second and subsequent sheets P at the upper floating position are bent downward and separated from the uppermost sheet P, the uppermost sheet P at the upper floating position is moved to the upper suction conveyance unit 12 side. Sucked.

  Specifically, the suction force from the suction conveyance unit 12 excludes the left and right ends covered with the left and right floating restriction plates 27 among the leading end side of the uppermost sheet P at the floating upper limit position facing the suction conveyance unit 12. Acts on the center. Accordingly, the central portion of the uppermost sheet P is sucked upward by the suction force from the suction conveyance unit 12.

  Note that the left and right ends of the uppermost sheet P, the flying of which is restricted by the left and right floating restriction plates 27, are sucked upward from the gap between the tips of the left and right floating restriction plates 27 by the suction conveyance unit 12. As the distance rises, it is drawn to the tip side of the lifting restriction plate 27 under the left and right lifting restriction plates 27.

  For this reason, the uppermost sheet P at the floating upper limit position is positioned such that the central portion in the width direction is positioned higher than the side end portion due to the suction force from above by the suction conveyance unit 12 and its own flexibility. To bend and deform. Then, when the central portion of the paper P is sucked upward and the left and right ends of the paper P drawn toward the leading end of the floating restriction plate 27 dodge the leading edge of the floating restriction plate 27, the paper P gets over the floating restriction plate 27. Then, it is adsorbed by the suction conveyance unit 12.

  When the uppermost sheet P at the floating upper limit position is sucked by the suction conveyance unit 12, the suction hole 12b of the belt 12a is blocked by the sucked sheet P. Then, the suction force of the suction conveyance unit 12 is consumed to attract the uppermost sheet P, and the suction force of the suction conveyance unit 12 does not act on the second and subsequent sheets P at the upper floating position.

  For this reason, the second and subsequent sheets P of the floating upper limit position whose flying is physically restricted by the floating restriction plate 27 are attracted to the suction conveyance unit 12 together with the uppermost sheet P of the floating upper limit position. Absent.

  The uppermost sheet P at the floating upper limit position adsorbed by the suction conveyance unit 12 is conveyed by the suction conveyance unit 12 toward the conveyance path R in a direction different from the suction direction of the sheet P. When the uppermost sheet P at the floating upper limit position is transported from the floating upper limit position, the stacking order of the sheets P positioned at the second sheet at the floating upper limit position before transporting is advanced to the top, 3 sheets The stacking order of the sheets P positioned after the first is advanced to the second and subsequent sheets.

  The sheet P at the floating upper limit position in which the stacking order is advanced from the second sheet to the top goes around the gap between the third sheet and the second sheet, and the uppermost position is stacked. From the state in which the central portion is bent downward by the obliquely upward separation air B blown on the lower surface of P, the air is expanded horizontally along the left and right levitation restricting plates 27. Then, it is separated from the second and subsequent sheets of paper P, sucked by the suction conveyance unit 12, and conveyed to the conveyance path R by the suction conveyance unit 12.

  Thereafter, each time the uppermost sheet P at the floating upper limit position is sucked and conveyed by the suction conveyance unit 12, the stacking order of the second and subsequent sheets P at the floating upper limit position is advanced one by one. Then, the uppermost sheet P at the floating upper limit position is sucked by the suction conveyance unit 12 and sequentially conveyed to the conveyance path R one by one.

  In this way, the sheets P that have been lifted to the floating upper limit position and bent so that the central portion in the width direction is positioned below the side end are attracted to the suction conveyance unit 12 one by one and are conveyed in the conveyance route R. It is conveyed to.

  Therefore, when the uppermost sheet P lifted by the air flow blown from the side onto the uppermost part of the stacked sheets P is sucked and transported by the suction transport unit 12, the second and subsequent sheets P are It is possible to prevent the suction and transport unit 12 from being sucked together with the uppermost sheet P and being double-fed to the transport path R.

  There are various types of paper P depending on the application. For example, the paper quality of the paper P includes plain paper, matte paper, thin paper, and additional paper with different surface textures (smoothness and roughness), and the print quality (resolution, glossiness, etc.) required for the image to be printed. It is used properly by.

  In addition to paper quality, depending on the durability required for the printed matter, the basis weight paper P corresponding to the strength of the stiffness can be used properly, the size (A4, A3, B4, B5, etc.) and orientation ( Different types of paper P (vertical and horizontal) may be used.

  Such a type of the paper P is an element that affects the ease of suction of the paper P by the suction conveyance unit 12.

  Therefore, the suction conveyance unit 12 and the floating restriction plate 27 are configured to be movable in the floating direction of the paper P using an elevating mechanism, and the suction conveyance unit 12 and the floating restriction in the floating direction of the paper P according to the type of the paper P. It is good also as a structure which adjusts the position of the board 27. FIG.

  By adopting this configuration, the suction conveyance unit 12 and the uppermost sheet P at the upper floating position are arranged in a positional relationship in which the suction conveyance unit 12 can appropriately adsorb the sheet P in the floating direction of the sheet P. be able to.

  When the position of the sheet P in the floating direction can be adjusted according to the type of the sheet P, only one of the suction conveyance unit 12 and the floating restriction plate 27 may be adjusted.

  The type of the paper P is an element that determines the flying distance of the paper P due to the air ejected from the floating air outlet 24 and the degree of deflection of the paper P due to the air ejected from the pressed air outlet 25.

  Therefore, a configuration may be adopted in which the air volume of the air ejected from the floating air outlet 24 and the pressed air outlet 25 can be changed and the air volume is adjusted according to the type of the paper P.

  By adopting this configuration, the flying distance of the paper P due to the air ejected from the floating air outlet 24 and the degree of bending of the paper P due to the air ejected from the pressed air outlet 25 are set to the highest floating upper limit position. The sheet P can be floated or bent in a size suitable for separating the upper sheet P from the second and subsequent sheets P.

  When the air volume can be adjusted according to the type of the paper P, the air volume can be adjusted by adjusting the air volume blown from the floating air outlet 24 and the air jetted from the pressed air outlet 25. Either one of the airflow or the other.

  Further, in the present embodiment, the case where the paper feeding device 20 is a part of the ink jet recording apparatus 1 (external paper feeding unit 11) has been described, but the present invention is an external device that is used by being connected to the ink jet recording apparatus 1. It can also be applied to an attached paper feeder.

  In the present embodiment, the case where the present invention is applied to the external paper feeding unit 11 of the inkjet recording apparatus 1 to configure the paper feeding device 20 that supplies the paper P to the transport path R has been described. The present invention can be widely applied to an apparatus that supplies thin sheets other than paper one by one to a supply target.

  Further, the structure in which air is blown from the floating air outlet 24 and the pressurized air outlet 25 to the side of the uppermost sheet P of the sheet feeder 21 is the same as the inkjet recording apparatus 1 of the present embodiment. May be provided on both the left and right sides of the leading end side of the paper P stacked on the paper sheet, or may be provided on only one of the left and right sides.

  Further, in addition to or instead of the floating air outlet 24 and / or the pressing air outlet 25 on both the left and right sides of the paper P, the conveyance direction of the paper P on the paper feed tray 21 (the front-rear direction in FIG. 1). A configuration may be provided in which air is blown from the floating air outlet 24 or the pressed air outlet 25 to the side of the uppermost paper P of the paper feed tray 21 on the rear side of the paper P in FIG.

  Further, in the present embodiment, the fan 28a that is an air supply source that is ejected from the floating air outlet 24 and the fan 29a that is an air supply source that is ejected from the pressed air outlet 25 are individually provided. However, a configuration may be adopted in which air is ejected from the floating air outlet 24 and the pressurized air outlet 25 using a common supply source.

  In that case, the air to be ejected from the floating air ejection port 24 and the pressing air ejection port 25, for example, individually set the flow channel cross-sectional areas of the air flow channels 28 and 29, and the air volume corresponding to each. Can do.

  In the present embodiment, the tip of the flying restriction plate 27 extends horizontally from the duct member 23 to the paper P side. However, as long as the bending direction of the second and subsequent sheets of paper P that have floated to the floating upper limit position can be guided downward, the tip of the floating restriction plate 27 may be extended from the duct member 23 in a direction other than horizontal.

  Further, in the present embodiment, the air A for separation and the air B for separation are blown from the front end surface side of the paper P to the uppermost part of the paper P stacked on the paper feed base 21 of the paper feeding device 20. However, this configuration may be omitted.

  And according to embodiment described above, invention of each aspect shown below is disclosed.

First, as an invention according to the first aspect,
A first jet port that blows air to the side of the uppermost part of the stacked sheets and jets air that floats the plurality of uppermost sheets and regulates the descent;
A levitation regulating unit that regulates the levitation of the sheet by the air ejected from the first ejection port at the levitation upper limit position;
By blowing air to the side of the sheet at the upper limit position where the movement in the vertical direction is restricted by the air ejected from the first jet port and the floating restriction part, the side end part of the sheet at the upper limit position A second jet port for jetting air that presses against the center side of the sheet and deflects the sheet;
A suction conveyance unit for sucking the sheet from above the floating upper limit position and conveying the sheet adsorbed by the suction;
Blowing the leading end of the sheet at the floating upper limit position in the conveying direction by the suction conveying unit, the second sheet from the upper floating position is bent in a direction where the center of the sheet is lower than the side end. A third jet outlet that ejects air that separates the first sheet from the second sheet from the levitation upper limit position,
Is disclosed.

  According to the sheet supply device of the invention according to the first aspect, the uppermost plurality of sheets among the stacked sheets are levitated from the stacked position by the jet of air ejected from the first ejection port. . The descending of the sheet that has floated is regulated by the air ejected from the first ejection port. The flying of the sheet is regulated by the flying regulation unit at the floating upper limit position.

  In this way, the deflection of the next sheet (the second sheet from the levitation upper limit position) following the uppermost sheet (first sheet from the levitation upper limit position) whose vertical movement is restricted at the levitation upper limit position. The direction is regulated so that the central portion of the sheet is positioned below the side end portion by the air blown from the third ejection port to the leading end portion of the sheet that has floated.

  The uppermost sheet (the first sheet from the upper levitation position) is the second sheet (the second sheet from the upper levitation position) by the air blown from the third ejection port. Separated from.

  Then, the uppermost sheet at the floating upper limit position separated from the second sheet by the air blown from the third ejection port is adsorbed by the suction conveyance unit by the suction force from above.

  The uppermost sheet at the floating upper limit position adsorbed by the suction conveyance unit is conveyed in a direction different from the sheet suction direction by the suction conveyance unit. When the uppermost sheet at the upper flying height position is transported from the upper flying height limit, the stacking order of the second sheet at the upper flying height position before transporting moves up to the top, and the third and subsequent sheets. The stacking order of the sheets located in is moved up to the second and subsequent sheets.

  The sheet at the upper limit position where the stacking order has been advanced from the second sheet to the top is the second and subsequent sheets whose stacking order has been increased from the third sheet after the upper limit position by the air blown from the third jet outlet. The sheet is separated from the sheet, adsorbed to the suction conveyance unit by the suction force from above, and conveyed by the suction conveyance unit.

  Thereafter, every time the uppermost sheet at the floating upper limit position is sucked and conveyed by the suction conveyance unit, the stacking order of the second and subsequent sheets at the floating upper limit position is advanced one by one. Then, the uppermost sheet at the levitation upper limit position is adsorbed by the suction conveyance unit and sequentially conveyed one by one.

  As described above, the sheets that are lifted to the floating upper limit position and bent so that the central portion is positioned below the side end portions are sucked and conveyed one by one by the suction conveyance unit.

  Therefore, when the top sheet lifted by the air flow blown from the side to the top of the stacked sheets is sucked and conveyed, the top sheet is securely separated from the following sheets. Thus, it is possible to suppress the next and subsequent sheets from being sucked together and double-fed.

  Next, as an invention according to a second aspect, a sheet supply device is disclosed in which the rising restriction portion restricts the floating of the side end portion of the sheet at the floating upper limit position.

  According to the sheet supply device of the invention according to the second aspect, since the floating regulating member regulates the floating of the sheet at the side end portion of the sheet, the floating regulating member when the suction conveying unit sucks the sheet is used. Interference is less likely to occur in the center of the sheet. Therefore, it is possible to efficiently apply the suction force of the suction conveyance unit from above to the central portion of the sheet bent downward, and to realize a configuration in which the uppermost sheet at the upper floating position is easily attracted to the suction conveyance unit. it can.

  Subsequently, as an invention according to a third aspect, a sheet feeding device is disclosed in which an interval between the suction conveyance unit and the floating upper limit position in the sheet floating direction is adjusted according to the type of the sheet.

  According to the sheet feeding apparatus of the invention according to the third aspect, the suction conveyance unit and the floating upper limit position in the sheet floating direction depend on the type of the sheet that affects the ease of suction of the sheet by the suction conveyance unit. The interval is adjusted. Here, the sheet type includes, for example, the texture (smoothness and roughness) of the sheet surface, the weight of the sheet, and the size of the sheet (paper quality, basis weight, and size when the sheet is a sheet). It is.

  For this reason, at least one of the position of the suction conveyance unit and the position of the levitation regulating member in the sheet floating direction can be adjusted, thereby sucking and conveying the suction conveyance unit and the uppermost sheet at the floating upper limit position. The portions can be arranged in a positional relationship where the sheet can be adsorbed appropriately.

  Next, as an invention according to a fourth aspect, the amount of air blown from at least one of the first outlet and the second outlet is adjusted according to the type of the sheet. An apparatus is disclosed.

  And according to the sheet supply apparatus of the invention according to the fourth aspect, depending on the type of sheet that affects the flying distance of the sheet by air and the degree of deflection of the sheet by air, At least one of the air volume of the air ejected from the second ejection port is adjusted. Here, the sheet type includes, for example, the texture (smoothness and roughness) of the sheet surface, the weight of the sheet, and the size of the sheet (paper quality, basis weight, and size when the sheet is a sheet). It is.

  For this reason, by allowing at least one of the air volume of the air jetted from the first jet outlet and the air volume of the air jetted from the second jet outlet to be adjustable, the flying height of the seat by the air jetted from the first jet outlet And at least one of the degree of bending of the sheet by the air ejected from the second ejection port can be set to a size suitable for reliably separating the uppermost sheet from the subsequent sheets.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Paper feed part 3 Printing part 3a Belt platen part 4A-4D Inkjet head 5A-5D Cleaning device 6 Head gap adjustment unit 9 Control part 10 Operation panel 11 External paper feed part 12 Suction conveyance part 12a Belt 12b Suction hole DESCRIPTION OF SYMBOLS 13 Internal paper feed stand 14 Internal paper feed roller 15 Internal paper feed conveyance roller 16 Registration roller 17a Floating air jet 18a Separation air jet (3rd jet)
20 Paper feeder (sheet feeder)
21 Feeding table 22 Floating unit 17, 18, 23 Duct member 24 Floating air outlet (first outlet)
25 Pressed air outlet (second outlet)
26 Guide plate 27 Levitation restriction plate (deflection restriction part, levitation restriction member)
28, 29 ... Air flow path 28a, 29a ... Fan A Air for floating B Air for separation P Paper (sheet)
R Transport route S Space

Claims (4)

A first jet port that blows air to the side of the uppermost part of the stacked sheets and jets air that floats the plurality of uppermost sheets and regulates the descent;
A levitation regulating unit that regulates the levitation of the sheet by the air ejected from the first ejection port at the levitation upper limit position;
Blowing the side of the sheet at the upper limit position of levitation by spraying it to the side of the upper limit position of the levitation, which is restricted from moving in the vertical direction by the air ejected from the first ejection port and the levitation restriction unit, A second jet port for jetting air that presses against the center side of the sheet and deflects the sheet;
A suction conveyance unit for sucking the sheet from above the floating upper limit position and conveying the sheet adsorbed by the suction;
Blowing the leading end of the sheet at the floating upper limit position in the conveying direction by the suction conveying unit, the second sheet from the upper floating position is bent in a direction where the center of the sheet is lower than the side end. A third jet outlet that ejects air that separates the first sheet from the second sheet from the levitation upper limit position,
A sheet supply apparatus comprising:   The sheet feeding apparatus according to claim 1, wherein the floating restriction unit restricts floating of the side end portion of the sheet at the floating upper limit position.   The sheet feeding device according to claim 1, wherein a distance between the suction conveyance unit and the upper limit of the flying height in the sheet floating direction is adjusted according to the type of the sheet.   The sheet supply apparatus according to claim 1, wherein an air volume of air ejected from at least one of the first ejection port and the second ejection port is adjusted according to a type of the sheet.

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