JP2011225289A - Paper feeder and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform floating and separation of sheets by blowing air to the sheets appropriately even if sheets of any width are loaded on a paper feed tray.SOLUTION: A first air blowing part 40A and a second air blowing part 40B are disposed on the side of sheets P loaded on the paper feed tray 31. The first air blowing part 40A and the second air blowing part 40B are controlled such that when the width of the sheets P interposed between the first air blowing part 40A and the second air blowing part 40B is a predetermined value or below, the volume of air blown by the first air blowing part 40A is smaller than that of air blown by the second air blowing part 40B.

Description

  The present invention relates to a sheet feeding device and an image forming apparatus.

  A paper feeding device that feeds paper to image forming apparatuses such as copiers, printers, facsimiles, printing machines, and multi-function machines, reliably separates multiple stacked sheets one by one to prevent paper jams. It is required to be fed. In recent years, there is a case where the coated paper is stacked on a paper feeding device to form an image on the coated paper, but the coated paper has strong adhesion between the papers, and it is difficult to separate and feed the paper one by one. There are cases.

  Therefore, a paper feeding device has been proposed in which a blower opening is provided on the side with respect to the feeding direction of the stacked paper, and air is blown from the blower opening to the side of the paper so that air enters between the papers and is separated. (For example, Patent Document 1).

  There is also a paper feeding device that blows air from the side of the stacked paper other than separating the paper. In the paper feeding device described in Patent Document 2, air is blown from the side of the paper loaded on the paper feeding tray, the uppermost paper among the stacked papers is floated, and the suction installed above the paper Paper is fed by the transport unit.

JP-A-7-277541 JP 2008-239312 A

  The paper feeding devices described in Patent Literature 1 and Patent Literature 2 blow air from the side of the stacked paper and blow air from both sides of the stacked paper. When the width of the loaded paper is reduced, the air vents on both sides to which air is blown are moved to bring the air vents on both sides closer to each other.However, if the same amount of air is blown from the air vents on both sides, They will collide with each other and the paper will not float or separate properly.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a paper feeding device and an image forming apparatus that can perform air floating or the like by appropriately blowing air to paper even when paper of any width is stacked on the paper feeding tray. is there.

In order to achieve the above object, a paper feeding device according to the present invention includes:
A paper tray for loading multiple sheets of paper,
A first air blower that is movable according to the size of the paper stacked in the paper feed tray and blows air onto the paper stacked in the paper feed tray from the side in the paper feeding direction;
It is movable according to the size of the paper loaded on the paper feed tray, and the first blower blows air onto the paper loaded on the paper feed tray from the side opposite to the side where the air blows. 2 air blowers,
A control unit for controlling the first air blowing unit and the second air blowing unit;
When the width of the paper sandwiched between the first air blowing unit and the second air blowing unit becomes a predetermined value or less, the control unit blows the air volume blown by the first air blowing unit. The first air blower and the second air blower are controlled so as to be less than the air flow rate.

An image forming apparatus according to the present invention is
It has the sheet feeding device, and forms an image on the sheet fed from the sheet feeding device.

  According to the sheet feeding device and the image forming apparatus according to the present invention, even when sheets of all widths are stacked on the sheet feeding tray, the sheet can be floated by appropriately blowing air onto the sheet.

1 is an overall configuration diagram of an image forming apparatus according to the present invention. It is a perspective view which shows the principal part of the paper feeder which concerns on this invention. It is a side view of a paper feeder. FIG. 3 is a plan view of a sheet feeding device. It is a front view of a paper feeder. It is sectional drawing which shows the conveyance process of the paper P by a suction conveyance part. FIG. 4 is a block diagram illustrating a control configuration of a sheet feeding device.

[Outline of image forming apparatus]
FIG. 1 is an overall configuration diagram of an image forming apparatus X according to the present invention.

  As shown in FIG. 1, the image forming apparatus X mainly includes an image forming apparatus main body A, an image reading apparatus SC, an automatic document feeder DF, and a paper feeder LT.

  The image forming apparatus main body A includes an image forming unit including a photosensitive member 1, a charging unit 2, an image exposing unit 3, a developing unit 4, a transfer unit 5, a cleaning unit 6 and the like, a fixing unit 7, and a paper transport system. ing. The paper transport system includes a paper feed cassette 10, a first paper feed unit 11, a second paper feed unit 12, a paper discharge unit 14, a transport path switching unit 15, a circulation refeed unit 16, and a reverse paper discharge unit 17. ing.

  The document d placed on the document table of the automatic document feeder DF is transported by the paper feed unit, the image on one or both sides of the document d is read by the optical system of the image reading device SC, and read by the image sensor CCD. It is. The analog signal photoelectrically converted by the image sensor CCD is subjected to analog processing, A / D conversion, shading correction, image compression processing and the like in the image processing unit 20 and then sent to the image exposure apparatus 3.

  In the image forming unit, a charge is added to the photosensitive member 1 by the charging unit 2, an electrostatic latent image is formed by laser light irradiation from the image exposure unit 3, and the electrostatic latent image is visualized by the developing unit 4. Into a toner image. Next, the paper P stored in the paper feed cassette 10 is conveyed from the first paper feed unit 11. The sheet P is conveyed in synchronization with the toner image by the second sheet feeding unit 12 made of registration rollers. Thereafter, the paper P is fixed by the fixing unit 7 after the toner image is transferred by the transfer unit 5.

  The paper P after fixing is discharged out of the apparatus by the paper discharge unit 14. On the other hand, the toner remaining on the photosensitive member 1 is removed by the cleaning unit 6. In the case of duplex printing, the paper P on which the image is formed on the first surface is sent to the circulation refeed unit 16 and reversed, and after the image is formed again on the second surface in the image forming unit, the paper discharge unit 14 is formed. Is discharged out of the apparatus. In the case of reverse paper discharge, the paper P branched from the normal paper discharge path is switched back and upside down in the reverse paper discharge unit 17 and then discharged out of the apparatus by the paper discharge unit 14.

[Outline of paper feeder]
The paper feeding device LT connected to the image forming apparatus main body A has a paper feeding device main body 30, a first air blowing unit 40A, a third air blowing unit 50, a suction conveyance unit 60, and the like, and accommodates a large amount of paper P. Then, the paper P is fed to the image forming apparatus main body A one by one.

  The sheet feeder main body 30 includes a sheet feed tray 31, a leading end restricting member 32, a trailing end restricting member 33, and a guide rail 34. The paper feed tray 31 is configured to be drawable from the paper feed device LT by the guide rail 34.

  2 is a perspective view showing a main part of the paper feeding device LT according to the present invention, FIG. 3 is a side view of the paper feeding device LT, FIG. 4 is a plan view of the paper feeding device LT, and FIG. FIG.

  The paper P stacked on the paper feed tray 31 is accommodated by a mechanism (not shown) so as to be lifted and lowered, and is fed in the direction of arrow a shown in FIGS.

  In the feeding direction of the paper P, the leading edge restricting member 32 restricts the position of the leading edge of the paper P, and the trailing edge restricting member 33 restricts the position of the trailing edge of the paper P. The position of the leading edge regulating member 32 is fixed, but the trailing edge regulating member 33 is movable in the paper P feeding direction.

  As shown in FIG. 3, the rear end regulating member 33 is provided with a height detection sensor PS <b> 1 that detects the height of the uppermost sheet P stacked on the paper feed tray 31. Since the first blower 40A and the like blow air on the paper P loaded on the paper feed tray 31, the height of the uppermost paper P loaded on the paper feed tray 31 is set to a predetermined height. The paper feed tray 31 moves up and down based on the detection result of the height detection sensor PS1.

  A suction conveyance unit 60 is installed above the paper P stacked on the paper feed tray 31. The suction conveyance unit 60 includes a suction belt 63 that rotates by winding a large roller 61 connected to a drive source and two small rollers 62. The suction belt 63 has a large number of small-diameter through holes. A suction fan 64 is installed inside the suction belt 63, and the paper P is sucked to the suction belt 63 by the suction force of the suction fan 64. When the suction belt 63 rotates while sucking the paper P, the uppermost paper P stacked on the paper feed tray 31 is fed in the direction of the arrow a and fed into the image forming apparatus main body A.

  A third air blower 50 is installed on the downstream side in the paper feeding direction with respect to the paper feed tray 31 and in the vicinity of the suction belt 63. The 3rd ventilation part 50 is comprised by the ventilation fan 51 grade | etc., And the ventilation port 53 from which the air blows off by the 3rd ventilation part 50 is attached upwards. The air blown upward is changed in direction by the guide plate 52, blown obliquely upward from the blower port 53, and blown to the vicinity of the suction belt 63 of the suction conveyance unit 60. As a result, air is blown between the sheets to ensure separation.

  As shown in FIG. 2 and the like, the first blower 40A and the second blower 40B that blow air onto the upper part of the paper P stacked on the paper feed tray 31 from the side with respect to the feeding direction of the paper P are It is installed on both sides of the paper tray 31. 40A of 1st ventilation parts are mainly comprised from 41 A of side part control members, and the ventilation fan 42A installed in the inside of 41 A of side part control parts, and the 2nd ventilation part 40B is mainly comprised of the side part control member 41B. The air supply fan 42B is installed inside the side regulating member 41B.

  As shown in FIG. 5, the first blower 40 </ b> A and the second blower 40 </ b> B are movable in the direction of arrow b, which is a direction intersecting with the feeding direction of the paper P, and are stacked on the paper feed tray 31. The user moves the first air blowing part 40A and the second air blowing part 40B according to the width of the paper P, and the positions of both sides of the paper P are restricted by the side restricting members 41A and 41B (on the paper feed tray 31). The stacked paper P is sandwiched between the first blower 40A and the second blower 40B).

  The first blower 40A blows air onto the paper P from the blower opening 43A provided on the upper side of the side regulating member 41B, and the second blower 40B is applied to the paper P from the blower opening 43A provided on the upper side of the side regulating member 41B. Blow air. That is, the second blower 40B blows air onto the paper P from the side opposite to the side where the first blower 40A blows air.

  The paper P blown with air from the first blower 40A and the second blower 40B floats upward and moves toward the suction conveyance unit 60 located above the paper P.

  Even when the size of the paper P loaded in the paper feed tray 31 is changed, the side surfaces of the paper P are regulated by the side regulating members 41A and 41B by moving the first blower 40A and the second blower 40B. Regardless of the size of paper P stacked, air can be blown by the first blower 40A and the second blower 40B.

  FIG. 6 is a cross-sectional view showing the transport process of the paper P by the suction transport unit 60.

  FIG. 6A shows a sheet adsorption process. The first blower 40 </ b> A and the second blower 40 </ b> B lift a small number of upper sheets P stacked on the paper feed tray 31 against their own weight, and are sucked by the intake air V <b> 1 due to the negative pressure of the suction belt 63. The air V <b> 2 blown up by the third blower 50 blows near the front bottom of the suction belt 63.

  FIG. 6B shows a paper separation process. When the blowing of air by the first blower 40A and the second blower 40B is stopped, the blow by only the third blower 50 passes between the uppermost sheet P1 and the lower sheet P2. The uppermost sheet P1 is sucked by the intake air V1 of the suction conveyance unit 60 and separated from the sheet P2. The sheet P2 below the separated uppermost sheet P1 is lowered by its own weight and is accommodated on the sheet P.

  After the separation of the paper P1 from the paper P2, the driving unit (not shown) of the suction conveyance unit 60 starts driving, and the single sheet P1 sucked by the suction belt 63 is conveyed.

  As described above, the paper P is floated and separated by the first air blowing unit 40A, the second air blowing unit 40B, the third air blowing unit 50, and the suction conveyance unit 60, and the paper P is conveyed from the paper feed tray 31 one by one. .

[Air volume adjustment]
Next, the air volume adjustment of the air blown from the first blower 40 and the second blower 50 will be described.

  As described above, the first air blowing unit 40A and the second air blowing unit 40B are installed on both sides of the paper feed tray 31, and air is blown from both sides of the paper P loaded on the paper feed tray 31. . The user moves the first blower 40A and the second blower 40B in the direction of the arrow b shown in FIG. 5 according to the width of the paper P stacked on the paper feed tray 31, and the paper is moved by the side regulating members 41A and 41B. The positions on both sides of P are restricted.

  When the width of the paper P stacked on the paper feed tray 31 is small and the distance t (t is also the width of the paper P) between the side regulating members 41A and 41B shown in FIG. However, if the same amount of air is blown from the air blowing ports 43A and 43B on both sides at this time, the air collides with each other and the air does not enter between the papers properly, and the paper P does not float properly.

  Therefore, the air flow of the first blower 40A and the second blower 40B is adjusted according to the width of the paper P. Hereinafter, this point will be described in detail.

  First, a control configuration related to the present invention will be described. FIG. 7 is a block diagram showing a control configuration of the sheet feeding device LT, and shows only a control configuration related to the present invention.

  The control unit 100 is installed in the sheet feeding device LT and controls the operation of the entire sheet feeding device LT. The control unit 100 is mainly configured by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., reads various control programs stored in the ROM, expands them in the RAM, Control the operation of each part.

  The control unit 100 refers to the data table stored in the storage unit 101 and adjusts the air volume of the blower fan 42A of the first blower unit 40A and the blower fan 42B of the second blower unit 40B. The control unit 100 also controls the operation of the blower fan 51 of the third blower unit 50 and the suction fan 64 of the suction conveyance unit 60.

  Next, the operation of adjusting the air volume of the first blower 40A and the second blower 40B will be described.

  When a job for feeding the paper P from the paper feeding device LT to form an image on the paper P is started in the image forming apparatus X, the control unit 100 first operates according to a predetermined program and refers to the attribute information of the job. Information on the width (t in FIG. 5) of the paper P included in the information is acquired. In the present embodiment, the information on the width of the paper P is information determined by the positions of the side regulating members 41A and 41B, but may be information directly input from the user by the operation display unit.

  Next, the control unit 100 determines the air volume of the first blower 40A and the second blower 40B based on the information on the width of the paper P. The operation for determining the air volume is performed by the control unit 100 with reference to a data table shown in Table 1 below, for example. The data table is stored in the storage unit 101 shown in FIG.

  The numerical value on the right side of the “−” mark in the “air volume” column is the output rate of the blower fan 42A in the first blower section 40A, and the numerical value on the left side of the “−” mark is the blower fan 42B in the second blower section 40B. Is the output rate.

  The operation in which the control unit 100 determines the air volume of the first air blowing unit 40A and the second air blowing unit 40B with reference to the data table of Table 1 will be described in detail. For example, the information on the width of the paper P acquired by the control unit 100 If it is 170 mm or more, since the 1st ventilation part 40A and the 2nd ventilation part 40B are separated, air does not collide with each other. Therefore, the air blow is blown onto the paper P with the same output rate of both the blower fans 42A and 42B.

  Further, if the information on the width of the paper P acquired by the control unit 100 is 138 mm or less, the first air blowing unit 40A and the second air blowing unit 40B are close to each other, and therefore equivalent air is blown from both sides of the paper P. Air will hit each other. Accordingly, the output rate of the blower fan 42A is 0%, no wind is generated, and the output rate of the blower fan 42B is 100%.

  If the information on the width of the paper P is between 139 and 169 mm, the first blower 40A and the second blower 40B are close to each other to some extent, so the output rate of the blower fan 42A is 30%, and the blower fan The output rate of 42B is set to 100%.

  Thus, when the width of the paper P sandwiched between the first blower 40A and the second blower 40B is equal to or smaller than a predetermined value (169 mm in Table 1), the air volume blown by the first blower 40A is changed to the first air blower 40A. 2 By reducing the amount of air blown by the air blower 40B, even if the paper P of any width is stacked on the paper feed tray 31, the air does not collide with each other and the air enters the paper well so that the paper P Will surface.

  Further, the first blower 40A blows according to the width of the paper P loaded on the paper feed tray 31 so as to determine the air volume of the first blower 40A and the second blower 40B using the data table of Table 1. If the ratio between the air volume and the air volume blown by the second air blowing unit 40B is changed (the ratio is changed in three stages in Table 1), the air with the optimum air volume is blown onto the paper P depending on the width of the paper P. As a result, the paper P is appropriately floated.

  In addition to the data table of Table 1, the air volume in the first blower 40A and the second blower 40B may be determined by the width of the paper P and the basis weight of the paper P. Table 2 below is a data table showing the relationship between the width of the paper P, the basis weight of the paper P, and the air volume in the first blower 40A and the second blower 40B.

  Similarly to Table 1, in Table 2, the numerical value on the right side of the “−” mark is the output rate of the blower fan 42A in the first air blowing section 40A, and the numerical value on the left side of the “−” mark is in the second air blowing section 40B. This is the output rate of the blower fan 42B. For example, “100% −0%” means that the output rate of the blower fan 42A is 0% and the output rate of the blower fan 42B is 100%.

  In the operation referring to the data table shown in Table 2, the air volume of the first air blowing unit 40A and the second air blowing unit 40B is determined based on the width information of the paper P and the basis weight information of the paper P. The basis weight information of the paper P is information that is directly input from the user by the operation display unit and stored in the storage unit 101, for example.

The operation in which the control unit 100 determines the air volume of the first air blowing unit 40A and the second air blowing unit 40B with reference to the data table of Table 2 will be described in detail. For example, the information on the width of the paper P acquired by the control unit 100 Is 170 mm or more, and the basis weight information of the paper P is 200 g / m ² or more. In this case, since the 1st ventilation part 40A and the 2nd ventilation part 40B are separated, air does not collide mutually. Further, since the paper P is heavy, it is necessary to blow air firmly in order to float the paper P. Accordingly, the blower fans 42A and 42B blow the air onto the paper P with the same output rate of 100%.

Further, it is assumed that the information on the width of the paper P acquired by the control unit 100 is 138 mm or less and the information on the basis weight of the paper P is less than 105 g / m ² . In this case, since the first blower 40A and the second blower 40B are close to each other, when the same air is blown from both sides of the paper P, the air collides with each other. Further, since the paper P is light, the paper P is likely to float even if the air volume is small. Accordingly, in consideration of the floating of the paper P and the power consumption, the output rate of the blower fan 42A is set to 0%, no wind is generated, and the output rate of the blower fan 42B is set to 100%.

  Thus, by considering the basis weight information of the paper P together with the information on the width of the paper P, the power consumption of the blower fans 42A and 42B is determined by determining the air volume of the first blower 40A and the second blower 40B. The sheet P can be appropriately floated while being suppressed.

  Although the present invention has been described with reference to FIGS. 1 to 7, the present invention is not limited to the embodiment, and the present invention can be modified or added without departing from the gist of the present invention. included.

  In the paper feeder LT in the present embodiment, air is blown from both sides of the paper P in order to float the paper P loaded on the paper feed tray 31, but air is blown from both sides of the paper to separate the paper. Even if the image forming apparatus is a simple image forming apparatus, if the air flow rate of the first air blowing unit 40A and the second air blowing unit 40B is adjusted as described above, the air does not collide with each other, and the air enters between the sheets and is appropriately separated. I can do it.

  Moreover, in this embodiment, although the ventilation fans 42A and 42B are installed in the inside of the side part regulating members 41A and 41B in the first blowing part 40A and the second blowing part 40B, the blowing fans 42A and 42B are side restricted. It may be fixed at a place other than the members 41 </ b> A and 41 </ b> B so that only the side regulating members 41 </ b> A and 42 </ b> B can be moved in the direction intersecting with the feeding direction of the paper P depending on the width of the paper P.

  Further, in the present embodiment, the operation of the blower fans 42A and 42B is controlled by the control unit 100 installed in the paper feeding device LTB. However, in the control unit installed in the image forming apparatus main body A, the blower fans 42A and 42B are controlled. The operation may be controlled.

  Further, both sides of the paper P loaded on the paper feed tray 31 are regulated by the side regulating members 41A and 41B. However, when the small size paper P is loaded, the side regulating members 41A and 41B are not moved. Alternatively, both sides of the paper P may be regulated by auxiliary guides installed on the side regulating members 41A and 41B.

  The image forming apparatus X according to the present embodiment includes the image forming apparatus main body A and the paper feeding device LT. The image forming apparatus main body A, the image reading device SC, and the automatic document feeder DF are combined into one device. The present invention may be applied to an image forming system configured and configured such that a separate sheet feeding device LT is connected to the apparatus.

X Image forming apparatus A Image forming apparatus main body SC Image reading apparatus DF Automatic document feeder LT Paper feeder 30 Paper feeder main body 31 Paper feed tray 32 Front end restricting member 33 Rear end restricting member 34 Guide rail 40A First air blower 40B 2nd ventilation part 41A, 42A Side part regulating member 42A, 42B Blower fan 43A, 43B Blower port 50 3rd ventilation part 60 Adsorption conveyance part 100 Control part 101 Storage part

Claims (5)

A paper tray for loading multiple sheets of paper,
A first air blower that is movable according to the size of the paper stacked in the paper feed tray and blows air onto the paper stacked in the paper feed tray from the side in the paper feeding direction;
It is movable according to the size of the paper loaded on the paper feed tray, and the first blower blows air onto the paper loaded on the paper feed tray from the side opposite to the side where the air blows. 2 air blowers,
A control unit for controlling the first air blowing unit and the second air blowing unit;
When the width of the paper sandwiched between the first air blowing unit and the second air blowing unit becomes a predetermined value or less, the control unit blows the air volume blown by the first air blowing unit. The sheet feeding device, wherein the first air blowing unit and the second air blowing unit are controlled so as to be less than an air flow rate.   The control unit has a ratio of an air volume blown by the first blower unit and an air volume blown by the second blower unit according to a width of a sheet sandwiched between the first blower unit and the second blower unit. The sheet feeding device according to claim 1, wherein the sheet feeding device is changed.   The said control part determines the air volume of the air which the said 1st ventilation part blows, and the air volume of the air which the said 2nd ventilation part blows by the basic weight of the paper loaded into the said paper feed tray. Paper feeder.   4. The sheet feeding device according to claim 1, further comprising a suction conveyance unit that is installed above the sheets stacked on the sheet feeding tray and sucks the sheets to convey the sheets.   An image forming apparatus comprising the paper feeding device according to claim 1, wherein an image is formed on paper fed from the paper feeding device.

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