JP5262828B2 - Paper feeding device, paper feeding unit, image forming apparatus, and image forming unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent double-feeding wherein paper is carried while being sucked on a suction surface, regardless of the size of the paper. <P>SOLUTION: Floating action timing at which paper P loaded on a paper placing stand 2 is floated, and separating action timing at which the paper P sucked on the suction surface 30b by a suction carrying mechanism 3 is separated are determined based on the presence/absence of sucking of the paper P to the suction surface 30b detected by a suction detection sensor 6, the carrying position of the paper P detected by a paper feeding detection sensor 39, and whether an auxiliary side surface guide 43 is in a projecting state or not, thereby driving a switching mechanism 55. Thus, when the auxiliary side surface guide 43 is in the projecting state, as compared with a case where the auxiliary side surface guide 43 is not in the projecting state, time which is the floating action timing is increased, and more air is blown from a floating auxiliary air blowout port 52 to the tip surface of the paper P loaded on the paper placing stand 2. Consequently, the double-feeding can be prevented, regardless of the size of the paper. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a paper feeding device, a paper feeding unit, an image forming apparatus, and an image which blows air to the edge of the loaded paper to float the paper and sucks and feeds the paper to a suction surface constituted by a conveyance belt or the like. It relates to the forming unit.

  In recent years, an air feeding device capable of feeding a large amount of paper has been used in an image forming apparatus such as a copying machine or a printer. The air feeding device blows air to the side of the loaded paper, floats the paper, sucks the paper with a suction surface such as a perforated belt with an air inlet that sucks air, and rotates the belt. Thus, the sheet is conveyed.

  Conventionally, such a paper feeding device feeds paper of only one size. However, in recent years, with the development of digital information technology, a printing method called print-on-demand, which directly prints data created by a computer or the like without going through the plate making process, has become widespread, and it is possible to feed paper of multiple sizes. A paper device is required.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a paper feeding device having an auxiliary side guide. According to Patent Document 1, an auxiliary side guide is provided on the side guide so as to protrude in the moving direction of the side guide in order to hold the side of the paper having a size smaller than the paper size that can hold the side by the side guide. The sheet whose side is held by the side guide is fed by the feed roller.

Japanese Patent Laying-Open No. 2006-327805 (FIG. 4)

  By the way, the paper feeding device described in Patent Document 1 can feed paper of various sizes by holding the side of the paper up to the postcard size with the auxiliary side guide. However, when this auxiliary side guide is applied to an air feeding device, the side surface of the paper held by the auxiliary side guide moves away from the air outlet provided in the side guide, so the paper does not sufficiently float, A suction failure may occur in which a sheet is not sucked on a suction surface constituted by a conveyance belt or the like.

  The present invention solves such a problem, and is capable of reliably adsorbing a sheet to an adsorption surface regardless of the type of paper, and capable of separating the adsorbed sheet into one sheet. It is an object to provide a paper unit, an image forming apparatus, and an image forming unit.

  In order to solve the above-described problem, a paper feeding device according to a first aspect of the present invention includes a paper mounting table on which a plurality of paper sheets are stacked and moved up and down along the paper stacking direction, and a width direction orthogonal to the paper transport direction. A first side end holding member that holds the side surface of the paper loaded on the paper mounting table, and a first side end holding member that protrudes in the moving direction of the first side end holding member. A second side end holding member that holds a side surface of a sheet that is narrower than a sheet held by the first side end holding member, and an adsorption surface that adsorbs the uppermost sheet. A suction conveyance mechanism for sucking the sheet held on the side by the side end holding member from the upper surface and sucking the sheet to the suction surface, and transporting the sheet sucked by the suction surface to the sheet conveyance path, and a first air outlet And a second air outlet provided above the first air outlet, the first air A blower mechanism that blows air from the air outlet to the front end surface of the paper loaded on the paper mounting table and blows air from the second air blower outlet to the front end surface of the paper that is adsorbed to the suction surface; A switching mechanism that is provided between the second air outlet and switches the distribution of the amount of air blown from the first and second air outlets, and detects whether or not the sheet is adsorbed on the adsorption surface. Suction detection sensor, paper feed detection sensor for detecting paper transported by the suction transport mechanism, presence or absence of paper suction on the suction surface detected by the suction detection sensor, transport of paper detected by the paper feed detection sensor Based on the position and whether or not the second side end holding member is in the protruding state, the floating operation timing for floating the paper stacked on the paper mounting table and the paper sucked on the suction surface by the suction conveyance mechanism are separated. Determine separation operation timing Te, is characterized in that a control unit for driving the switching mechanism.

  In the sheet feeding device according to claim 1, the sheet loaded on the sheet loading table is floated based on the detection result of the suction detection sensor and the sheet feeding detection sensor and whether the second side end holding member is in the protruding state. The control unit determines whether it is a floating operation timing to be performed or a separation operation timing for separating the sheet adsorbed on the adsorption surface by the adsorption conveyance mechanism.

  The control unit switches the switching mechanism so that air is blown out from the first air blowing outlet at the timing of the flying operation, and air is supplied from the first air blowing outlet to the front end surface of the paper loaded on the paper placing table. Spray. Further, at the separation operation timing, the switching mechanism is switched so that air is blown out from the second air outlet, and air is blown from the second air outlet to the leading end surface of the paper adsorbed on the suction surface.

  In addition, when the second side end holding member is in the protruding state, the control unit increases the time that is the timing of the levitation operation to increase the first air blowing time than when the second side end holding member is not in the protruding state. A large amount of air is blown from the exit to the front end surface of the paper loaded on the paper placement table.

  As a result, air is blown from the front end surface of the paper loaded on the paper mounting table until the paper is adsorbed on the adsorption surface, and the paper is surely lifted and adsorbed on the adsorption surface regardless of the size of the paper. Will be able to. In addition, after the sheet is adsorbed on the adsorption surface, air is blown from the front end surface of the sheet adsorbed on the adsorption surface. As a result, paper other than the uppermost sheet adsorbed on the adsorption surface can be separated regardless of the size of the sheet.

According to a second aspect of the present invention, in the paper feeding device according to the first aspect, when the second side end holding member is not in the protruding state, the first mode is set, and the second side end holding member is set in the protruding state. In the first mode, when the suction detection sensor does not detect the paper , the control unit drives the switching mechanism so that the front end surface of the paper from the first air outlet. When the suction detection sensor detects the suction of the paper, the switching mechanism is driven to blow the air from the second air outlet to the front end surface of the paper sucked on the suction surface. In the mode, when the suction detection sensor does not detect the paper, the switching mechanism is driven to blow air from the first air outlet to the front end surface of the paper, and the suction detection sensor detects the suction of the paper, And the paper feed detection sensor is not detecting paper Drives the switching mechanism blows air to the leading end of the sheet sucked by the suction surface from the second air outlet, suction detecting sensor detects the adsorption of the paper, and the paper feed sensor detects the paper During this period, the switching mechanism is driven to blow air from the first air outlet to the front end surface of the paper.

In the paper feeding device according to claim 2, in the first mode, in addition to the air blown out from the air blowout port originally used for floating , the paper blown out from the first air blowout port is surely secured. Can surface. In the second mode, when the suction detection sensor does not detect the paper, the switching mechanism is driven to blow air from the first air outlet to the leading edge of the paper, and the suction detection sensor picks up the paper. During the period when the sheet is detected and the sheet detection sensor is not detecting the sheet, the switching mechanism is driven to blow air from the second air outlet to the leading end of the sheet adsorbed on the adsorption surface. detecting the adsorption of the sheet, and the period in which the sheet feeding sensor is detecting the sheet by driving the switching mechanism, since blow air from the first air outlet to the front end surface of the paper, the paper on the suction surface Until it is sucked, air is blown from the front end surface of the paper loaded on the paper mounting table, and paper having a small size such as A6, B6 size, postcard size, etc. is surely floated and sucked on the suction surface You can To become. In addition, after the sheet is adsorbed on the adsorption surface, air is blown from the front end surface of the sheet adsorbed on the adsorption surface. Thus, it is possible to separate the sheets other than the uppermost sheet adsorbed on the adsorption surface.

According to a third aspect of the present invention, there is provided a sheet feeding unit including one or a plurality of sheet trays in which sheets are stored, a sheet placing table on which a plurality of sheets are stacked and moved up and down along the sheet stacking direction, A first side end holding member that can move in the width direction orthogonal to the transport direction, and that holds the side surface of the paper stacked on the paper mounting table, and a first side end that can protrude in the movement direction of the first side end holding member. Provided on the side end holding member, and has a second side end holding member that holds the side surface of the paper that is narrower than the paper held by the first side end holding member, and an adsorption surface that adsorbs the uppermost paper. A suction conveyance mechanism for sucking the sheet held on the side by the first or second side end holding member from the upper surface and sucking the sheet to the suction surface, and for transporting the sheet sucked by the suction surface to the sheet conveyance path; The second air outlet is provided above the first air outlet and the first air outlet. An air blowout port, air is blown from the first air blowout port to the front end surface of the paper loaded on the paper mounting table, and air is blown from the second air blowout port to the front end surface of the paper adsorbed on the suction surface. An air blowing mechanism for blowing air, a switching mechanism that is provided between the air blowing mechanism and the first and second air outlets, and switches the distribution of the amount of air blown from the first and second air outlets; A suction detection sensor for detecting whether or not the paper is sucked on the surface, a paper feed detection sensor for detecting the paper transported by the suction transport mechanism, and whether or not the paper is sucked to the suction surface detected by the suction detection sensor , A floating operation timing for floating the paper loaded on the paper mounting table based on the paper conveyance position detected by the paper feed detection sensor and whether or not the second side end holding member is in the protruding state, and suction conveyance The paper sucked on the suction surface by the mechanism is separated. To determine separation operation timing of, is characterized in that a control unit for driving the switching mechanism.

In the paper feeding unit according to the third aspect , by providing the paper feeding device described above, the paper can be surely lifted and sucked on the suction surface, and other than the uppermost paper sucked on the suction surface can be separated. can do.

According to a fourth aspect of the present invention, there is provided an image forming apparatus for forming an image on a sheet, a sheet placing table on which a plurality of sheets are stacked and moved up and down along the sheet stacking direction, and a sheet conveying direction orthogonal to the sheet conveying direction. A first side end holding member that is movable in the width direction and that holds the side surface of the paper loaded on the paper placing table, and a first side end holding member that can protrude in the moving direction of the first side end holding member A second side end holding member that holds a side surface of a sheet that is narrower than a sheet held by the first side end holding member, and an adsorption surface that adsorbs the uppermost sheet, A suction conveyance mechanism that sucks the sheet held on the side by the second side end holding member from the upper surface and sucks the sheet onto the suction surface, and transports the sheet sucked on the suction surface to the image forming unit, and first air A second air outlet provided above the air outlet and the first air outlet; A blower mechanism that blows air from the first air outlet to the front end surface of the paper loaded on the paper mounting table and blows air from the second air outlet to the front end surface of the paper adsorbed to the suction surface; A switching mechanism that is provided between the first and second air outlets and switches the distribution of the amount of air blown from the first and second air outlets, and whether or not the sheet is adsorbed to the adsorption surface A suction detection sensor for detecting the paper, a paper feed detection sensor for detecting the paper transported by the suction transport mechanism, and the presence or absence of the suction of the paper to the suction surface detected by the suction detection sensor. Based on whether or not the transport position of the paper and the second side end holding member are in the protruding state, the floating operation timing for floating the paper loaded on the paper mounting table, and the paper sucked on the suction surface by the suction transport mechanism Separating operation timin to isolate To determine the one in which to drive the switching mechanism, characterized in that it comprises a control unit that performs control to form an image by the image forming unit.

In the image forming apparatus according to the fourth aspect , the paper feeding device described above is provided, so that the paper can be surely lifted and sucked to the suction surface, and other than the uppermost paper sucked to the suction surface can be separated. can do.

An image forming unit according to a fifth aspect includes an image forming unit that forms an image on a sheet, a sheet feeding device that feeds the sheet to the image forming unit, and a sheet that is fed from the sheet feeding unit to the image forming unit. And a control unit that performs control to form an image in the unit, and the sheet feeding device has a sheet placement table on which a plurality of sheets are stacked and moves up and down along the sheet stacking direction, and a width orthogonal to the sheet transport direction. The first side end holding member that can move in the direction and holds the side surface of the paper loaded on the paper placing table, and the first side end holding member that can protrude in the moving direction of the first side end holding member. A second side end holding member that holds the side surface of the paper that is narrower than the paper held by the first side end holding member, and an adsorption surface that adsorbs the uppermost paper, When the paper whose side surface is held by the side edge holding member 2 is sucked from the top surface and sucked to the suction surface, A suction transport mechanism for transporting the paper adsorbed on the suction surface to the paper transport path, a first air outlet, and a second air outlet provided above the first air outlet, A blower mechanism that blows air from the first air outlet to the front end surface of the paper loaded on the paper mounting table and blows air from the second air outlet to the front end surface of the paper adsorbed to the suction surface; A switching mechanism that is provided between the first and second air outlets and switches the distribution of the amount of air blown from the first and second air outlets, and whether or not the sheet is adsorbed to the adsorption surface A suction detection sensor for detecting the paper and a paper feed detection sensor for detecting the paper transported by the suction transport mechanism, and the control unit detects whether or not the paper is sucked to the suction surface detected by the suction detection sensor. The paper transport position detected by the paper detection sensor and the second side edge Based on whether or not the holding member is in a protruding state, a floating operation timing for floating the paper loaded on the paper mounting table and a separation operation timing for separating the paper sucked on the suction surface by the suction conveyance mechanism are determined. The switching mechanism is driven.

In the image forming unit according to the fifth aspect , by providing the above-described paper feeding unit, the paper can be surely lifted and sucked on the suction surface, and other than the uppermost paper sucked on the suction surface can be separated. can do.

  According to the paper feeding device of the present invention, air is blown from the front end surface of the paper loaded on the paper placing table until the paper is sucked on the suction surface, and the paper is surely lifted regardless of the paper size. It can be made to adsorb | suck to an adsorption | suction surface. As a result, it is possible to prevent a suction failure in which the paper is not attracted to the suction surface.

  In addition, after the paper is adsorbed on the adsorption surface, air is blown from the front end surface of the paper adsorbed on the adsorption surface. Thus, it is possible to separate the sheets other than the uppermost sheet adsorbed on the adsorption surface regardless of the size of the sheet. Thereby, it is possible to prevent the occurrence of double feeding in which a plurality of sheets are conveyed while being attracted to the attracting surface.

  According to the paper feeding unit of the present invention, by providing the above-described paper feeding device, it is possible to prevent a suction failure in which the paper is not attracted to the suction surface regardless of the size of the paper, and a plurality of sheets of paper to the suction surface. It is possible to prevent double feeding that is conveyed while being adsorbed.

  According to the image forming apparatus of the present invention, by providing the above-described paper feeding device, it is possible to prevent a suction failure in which the paper is not attracted to the suction surface regardless of the size of the paper, and a plurality of sheets of paper to the suction surface. It is possible to prevent double feeding conveyed in the sucked state, and to improve image quality.

  According to the image forming unit of the present invention, by providing the above-described paper feeding unit, it is possible to prevent a suction failure in which the paper is not attracted to the suction surface regardless of the size of the paper, and a plurality of sheets to be on the suction surface. It is possible to prevent double feeding conveyed in the sucked state, and to improve image quality.

1 is a side view illustrating a configuration example of a sheet feeding device 1 according to the present invention. 2 is a front view illustrating a configuration example of a sheet feeding device 1. FIG. 3 is a perspective view illustrating a configuration example of a sheet storage unit 20. FIG. 3 is a block diagram illustrating a configuration example of a control system of the sheet feeding device 1. FIG. 6 is a side view illustrating an operation example of the sheet feeding device 1. FIG. 6 is a time chart illustrating an example of an operation in a first mode of the sheet feeding device 1; 6 is a time chart illustrating an operation example of a second mode of the sheet feeding device 1; 3 is an explanatory diagram illustrating a configuration example of a sheet feeding unit 90. FIG. 2 is an explanatory diagram illustrating a configuration example of an image forming apparatus 100. FIG. 2 is an explanatory diagram illustrating a configuration example of an image forming unit 110. FIG.

  Hereinafter, a sheet feeding device, a sheet feeding unit, an image forming apparatus, and an image forming unit will be described as an example of the present invention with reference to the drawings.

<Configuration Example of Paper Feed Device 1>
As shown in FIGS. 1 to 3, the paper feeding device 1 includes a suction conveyance mechanism 3 that sucks and feeds the paper P stacked on the paper placement table 2, and a width direction orthogonal to the conveyance direction of the paper P indicated by an arrow F. The side guide 4 that is a first side end holding member that supports the sheet P so that the sheet P does not move by contacting the side surface of the sheet P stacked on the sheet placing table 2 and the moving direction of the side guide 4 And an auxiliary side guide 43 that is a second side end holding member that is provided on the side guide 4 so as to protrude freely and supports the side of the paper that is narrower than the paper supported by the side guide 4. Further, the paper feeding device 1 blows the floating auxiliary air A1 to the front end surface of the paper P from a floating auxiliary air outlet (hereinafter referred to as an outlet 52) located in front of the conveyance direction, and the paper sucked by the suction conveyance mechanism 3 A floating / separating air blowing mechanism (hereinafter referred to as a blowing mechanism 5) that blows separation air A2 from a separation air blowing outlet (hereinafter referred to as a blowing outlet 50) in front of the conveyance direction to P, and is blown out from the blowing mechanism 5. And a switching mechanism 55 that switches the air to the air outlet 52 or the air outlet 50.

  In the paper feeding device 1, whether or not the paper P is sucked by the suction transport mechanism 3, the position where the paper P fed out by the suction transport mechanism 3 is transported, and the auxiliary side guide 43 protrude in the moving direction of the side guide 4. The switching mechanism is synchronized with the timing when the sheet P loaded on the sheet placing table 2 is lifted and the timing when the sheet P sucked by the suction conveyance mechanism 3 is separated and separated into one sheet. 55 is controlled so that it can be switched.

  Details of the sheet feeding device 1 according to the present embodiment will be described below. The sheet feeding device 1 includes a sheet loading table 2 in a sheet storage unit 20 in which a space that can be stored in a form in which a predetermined number of sheets P are stacked is formed.

  The sheet placing table 2 is moved up and down along the stacking direction of the sheets P by a lifting mechanism (not shown). In the paper storage unit 20, a paper front end abutting surface 21 that holds the front end position of the paper P loaded on the paper placement table 2 is formed along the elevation direction of the paper placement table 2.

  The paper feeding device 1 includes an upper limit detection sensor 22 that detects the upper surface position Pu of the paper P stacked on the paper placement table 2. The upper limit detection sensor 22 includes, for example, a pair of optical sensors in which a detection position is formed at a predetermined position of the paper leading end abutting surface 21 along the stacking direction of the sheets P, and the upper limit detection sensor 22 of the sheets P stacked on the sheet mounting table 2. The upper surface position Pu is disposed at a position where it is detected that the upper surface position Pu is at the height H1 that can be sucked by the suction conveyance mechanism 3. For example, the output of the upper limit detection sensor 22 is OFF when there is no paper P at the suckable height H1, and the output is ON when the paper P is at the suckable height H1.

  In the sheet feeding device 1, when the stacking height of the sheet P on the sheet mounting table 2 is reduced by feeding out the sheet P stacked on the sheet mounting table 2 by the suction conveyance mechanism 3, the upper surface position Pu of the sheet P is changed. The sheet placing table 2 is raised to a position detected by the upper limit detection sensor 22, and the upper surface position Pu of the sheet P stacked on the sheet placing table 2 is controlled to be a height H 1 that can be sucked by the sucking and conveying mechanism 3. The

  The suction conveyance mechanism 3 includes a conveyance belt 30 at an upper portion of the paper storage unit 20. Further, the suction conveyance mechanism 3 includes a driving roller 31 around which the conveyance belt 30 is wound, a first driven roller 32, and a second driven roller group 33 having two driven rollers.

  The conveyance belt 30 is endless, and the intake ports 30 a penetrating the conveyance belt 30 are arranged in parallel in the width direction of the conveyance belt 30, and a plurality of intake ports 30 a arranged in parallel in the width direction of the conveyance belt 30 are arranged in the conveyance belt 30. It is formed over the entire length direction orthogonal to the width direction.

  The drive roller 31 has an axis in a direction orthogonal to the conveyance direction of the paper P indicated by the arrow F, and is driven to rotate by a motor described later with reference to FIG. The first driven roller 32 and the second driven roller group 33 have an axis substantially parallel to the axis of the driving roller 31 and are freely rotatable following the rotation of the conveyor belt 30 when the driving roller 31 is driven to rotate. It is a simple configuration.

  In the suction conveyance mechanism 3, the second driven roller group 33 is disposed in front of the paper leading edge abutting surface 21 in the conveyance direction of the paper P indicated by the arrow F. In addition, a driving roller 31 is arranged on the upper part of the sheet placing table 2. Further, a first driven roller 32 is disposed between the second driven roller group 33 and the driving roller 31 on the upper part of the sheet placing table 2.

  In the suction conveyance mechanism 3, the conveyance belt 30 is stretched along the conveyance direction of the paper P between the driving roller 31 and the second driven roller group 33. Thus, the suction conveyance mechanism 3 has the rear end side wound around the driving roller 31 of the conveyance belt 30 positioned above the paper P stacked on the paper placement table 2, and the second driven roller of the conveyance belt 30. The leading end side wound around the group 33 is positioned in front of the sheet leading end abutting surface 21. Further, in the suction conveyance mechanism 3, the two conveyance belts 30 are arranged side by side with respect to the conveyance direction of the paper P. When the driving roller 31 is rotationally driven in the direction indicated by the arrow, each conveying belt 30 rotates, and the side of the conveying belt 30 facing the paper placing table 2 moves in the conveying direction of the paper P indicated by the arrow F.

  The lower end position on the circumferential surface of the drive roller 31 and the lower end position on the circumferential surface of the first driven roller 32 are configured to have substantially the same height. On the other hand, in the second driven roller group 33, the lower end position on the circumferential surface of the lower driven roller is configured to be higher than the lower end position of the first driven roller 32 by a predetermined amount. .

  As a result, the surface formed between the driving roller 31 and the first driven roller 32 on the side of the conveying belt 30 facing the paper mounting table 2 is the surface of the paper P stacked on the paper mounting table 2. It becomes almost parallel. On the other hand, the surface between the first driven roller 32 and the second driven roller group 33 is inclined upward along the conveyance direction of the paper P, and the conveyance belt 30 is the first driven roller. A portion wound around the roller 32 has a bent surface.

  The suction transport mechanism 3 includes a suction chamber 34 into which air that sucks the paper P is sucked onto the transport belt 30. The suction chamber 34 has a space in which air is sucked by a fan (not shown) formed inside the conveyance belt 30, and a lower side facing the conveyance belt 30 located on the side facing the sheet placement table 2 is opened. Air is sucked in from the air inlet 30a of the conveyor belt 30 on the side facing 2.

  In the suction conveyance mechanism 3, when the air in the suction chamber 34 is sucked by a fan (not shown), the suction chamber 34 becomes negative pressure, so that the suction chamber 34 has a negative pressure from the suction port 30 a of the transport belt 30 located on the side facing the sheet placing table 2. Air is sucked in, and a flow of air that adsorbs the paper P to the transport belt 30 on the side facing the paper placement table 2 is generated.

  Accordingly, the suction surface 30b that sucks the paper P is configured by the transport belt 30 facing the paper placement table 2 in which air is sucked into the suction chamber 34 from the suction port 30a.

  The sheet feeding device 1 includes a sheet conveyance path 35 through which the sheet P fed out by the suction conveyance mechanism 3 is conveyed. The sheet conveyance path 35 includes a guide member that guides conveyance of the sheet P sucked and fed out by the adsorption conveyance mechanism 3, and includes a conveyance belt 30 on the side facing the sheet placement table 2 and a sheet leading end abutting surface 21. A sheet entrance 36 through which the sheet P enters is formed between the upper end.

  The sheet feeding device 1 includes a conveyance roller 37 and a driven roller 38 facing the conveyance roller 37 in the sheet conveyance path 35. The conveyance roller 37 is rotationally driven by a motor, which will be described later with reference to FIG. 4, and conveys the paper P fed by the suction conveyance mechanism 3 while being sandwiched between the driven roller 38.

  The paper feed device 1 includes a paper feed detection sensor 39 in the paper transport path 35. The paper feed detection sensor 39 is composed of, for example, a pair of optical sensors in which a detection position is formed on the upstream side of the transport roller 37 and the driven roller 38, and is fed out by the suction transport mechanism 3 and transported by the transport roller 37. Is detected. For example, the output of the paper feed detection sensor 39 is turned on when the leading edge of the paper P fed out by the suction transport mechanism 3 reaches, and the output is turned off when the paper P is transported by the transport roller 37 and the rear end of the paper P comes out. .

  In the side guide 4, a floating air outlet (hereinafter referred to as an outlet 40) is formed as an air outlet on the side of the paper storage unit 20. In the side guide 4, the air sucked by the blower fan 41 is blown out as floating air A <b> 3 from the blowout port 40 through the duct 42.

  The side guide 4 is provided with an auxiliary side guide 43. As shown by the two-dot chain line in FIG. 1 and FIG. 3, the auxiliary side guide 43 can freely protrude by rotating in the side direction of the paper P around the auxiliary side guide shaft 43 a. It is possible to support the side surface of a paper (for example, a postcard or a paper of A6 or B6 size or smaller) having a narrower width than the paper supported by. Further, an auxiliary side guide sensor 44 is provided on the upper side of the side guide 4. The auxiliary side guide sensor 44 is a sensor that determines whether or not the auxiliary side guide 43 protrudes in the moving direction of the side guide 4. The auxiliary side guide sensor 44 may be configured by an optical sensor or the like, or may be configured by a switch or the like.

  The blower mechanism 5 includes a blowout port 52 that blows out the floating auxiliary air A1, a blowout port 50 that blows out the separation air A2, and a switching mechanism 55 that switches the distribution of the amount of air blown from the blowout port 52 and the blowout port 50. . In the air blowing mechanism 5, when a solenoid described later in FIG. 4 of the switching mechanism 55 is driven to rotate the switching plate 53 provided on the support shaft 54 to close the air outlet 50, the air is sucked in by the air blowing fan 51. Air is blown out from the blowout port 52 toward the front end surface of the paper P. The floating auxiliary air A1 blown out from the blowout port 52 is blown together with the floating air A3 blown out from the blowout port 40 in a substantially horizontal direction with respect to the paper P. Further, in the air blowing mechanism 5, when the solenoid of the switching mechanism 55 is driven to rotate the switching plate 53 provided on the support shaft 54 to close the air outlet 52, the air outlet 50 is obliquely directed toward the transport belt 30. Is blown out. The separation air A <b> 2 blown out from the blowout port 50 is oriented along the conveyance belt 30 on the side facing the sheet placement table 2, and is substantially from the front of the sheet P sucked by the conveyance belt 30 with respect to the sheet P. Sprayed in a horizontal orientation.

  The sheet feeding device 1 includes a suction detection sensor 6 that detects the presence or absence of the paper P that is sucked to the transport belt 30 by the suction transport mechanism 3. The suction detection sensor 6 includes, for example, a pair of optical sensors, and detects the presence or absence of the detector 60 that is pushed up and displaced by the paper P sucked by the transport belt 30 by the suction transport mechanism 3. That is, when the sheet P is adsorbed to the conveyance belt 30 by the adsorption conveyance mechanism 3, a force for pushing up the detector 60 protruding from the adsorption surface 30b formed by the conveyance belt 30 is applied. When a force for pushing up the detector 60 is applied, the spring 61 is elastically deformed, and the detector 60 rotates about the shaft 62 and is displaced in the retracted direction with respect to the suction surface 30b. Further, when the sheet P attracted to the transport belt 30 disappears, the force for pushing up the detector 60 is not applied, and the detector 60 is rotated about the shaft 62 by the elastic force of the spring 61 and protrudes from the suction surface 30b. Displace in the direction of

  As described above, the detector 60 is displaced by the rotation operation depending on whether or not the sheet P is attracted to the transport belt 30 by the suction transport mechanism 3. For example, the output of the suction detection sensor 6 is turned off when the paper P is not attracted to the transport belt 30, and the output is turned on when the paper P is attracted to the transport belt 30. Thereby, it can be determined from the output of the suction detection sensor 6 whether or not the paper P is sucked onto the transport belt 30.

<Control Example of Paper Feed Device 1>
As shown in FIG. 4, the sheet feeding device 1 performs a sheet feeding control for feeding out the sheets P stacked on the sheet placing table 2 described with reference to FIG. S1 is provided.

  The control unit S1 detects from the output of the suction detection sensor 6 that the paper P is sucked to the transport belt 30 by the suction transport mechanism 3 shown in FIG. The control unit S1 detects from the output of the paper feed detection sensor 39 that the leading and trailing edges of the paper P fed out by the suction conveyance mechanism 3 have reached predetermined positions. The control unit S <b> 1 detects from the output of the auxiliary side guide sensor 44 whether or not the auxiliary side guide 43 is in a protruding state that is a state of protruding in the side direction of the paper P.

  The control unit S1 determines whether or not the sheet P is attracted to the transport belt 30 detected by the suction detection sensor 6, the transport position of the sheet P detected by the paper feed detection sensor 39, and whether the auxiliary side guide sensor 44 is in a protruding state. Based on whether or not, the switching plate 53 of the switching mechanism 55 is operated so as to close the air outlet 50 or the air outlet 52. The control unit S1 controls the driving of the solenoid SD1 included in the switching mechanism 55 to rotate the switching plate 53 so that the air sucked in by the blower fan 51 is blown out from the blowout port 50 or blown out from the blowout port 52. Can be switched.

  The control unit S1 switches to the first mode when the auxiliary side guide sensor 44 determines that the auxiliary side guide 43 is not in the protruding state, and switches to the first mode when determining that the auxiliary side guide 43 is in the protruding state. Switch to. The first mode is used when the side guide 4 holds, for example, A5 and B5 size paper, and is a mode in which the time during which air is blown out from the air outlet 52 is less than in the second mode. The second mode is a mode in which the auxiliary side guide 43 is used, for example, when holding a postcard size or A6, B6 size paper, and the time during which air is blown out from the air outlet 52 is longer than the first mode. .

  Further, the control unit S1 detects whether or not the sheet P is attracted to the transport belt 30 detected by the suction detection sensor 6, the transport position of the sheet P detected by the paper feed detection sensor 39, and the auxiliary side guide sensor 44. The motor M1 that drives the conveyance belt 30 and the motor M2 that drives the conveyance roller 37 are controlled depending on whether or not the auxiliary side guide 43 is in the protruding state. Based on the upper surface position of the paper P detected by the upper limit detection sensor 22, the control unit S <b> 1 controls the motor M <b> 3 that raises and lowers the paper mounting table 2, and determines the upper surface position Pu of the paper P stacked on the paper mounting table 2. To the height H1 that can be fed.

<Operation Example of Paper Feeding Device 1>
An operation example of the sheet feeding device 1 when it is assumed that the auxiliary side guide 43 is not used will be described. When the auxiliary side guide 43 is not used, the control unit S1 operates the paper feeding device 1 in the first mode, which is a mode in which the auxiliary side guide 43 is not used, based on the output of the auxiliary side guide sensor 44. When the control unit S1 starts the paper feeding operation, the upper surface position Pu of the paper P stacked on the paper placement table 2 becomes the suctionable height H1 by the suction conveyance mechanism 3 based on the output of the upper limit detection sensor 22. In this manner, the motor M3 that raises and lowers the sheet placing table 2 is controlled.

  In the paper feeding operation of the paper P, a fan (not shown) of the suction conveyance mechanism 3 is driven and the blower fans 41 and 51 are driven. First, the paper P is floated and sucked.

  As shown in FIG. 5A, in the floating and suction operations of the paper P, when it is determined from the output of the suction detection sensor 6 that the paper P is not attracted to the conveyor belt 30, the control unit S1 causes the switching mechanism 55 to The solenoid SD1 is driven to rotate the switching plate 53 around the support shaft 54 so as to close the outlet 50.

  In the air blowing mechanism 5, when the air blowing fan 51 is driven and the floating auxiliary air A <b> 1 is blown out from the air outlet 52 in a state where the switching plate 53 is closed in the air outlet 50, the paper P loaded on the paper mounting table 2 is discharged. Levitation auxiliary air A1 is blown onto the tip surface.

  As a result, the paper P stacked on the upper side of the paper P stacked on the paper mounting table 2 starts to float. A time t1 shown in FIG. 6 is a time for waiting for the floated paper P to be attracted to the transport belt 30 after starting the paper feeding operation, and the floating motion timing TU determined from the output of the suction detection sensor 6. It is.

  When the air in the suction chamber 34 is sucked in by a fan (not shown), the suction chamber 34 becomes negative pressure, so that air is sucked in from the suction port of the transport belt 30 located on the side facing the paper placing table 2, A flow of air that adsorbs the paper P is generated on the conveyance belt 30 on the side facing the mounting table 2.

  The uppermost sheet P stacked on the sheet placing table 2 is adsorbed by the conveyance belt 30 constituting the adsorption surface 30b at the timing ta shown in FIG. When the paper P is sucked by the transport belt 30, the detector 60 constituting the suction detection sensor 6 is pushed up by a force that sucks the paper P. In the detector 60, the spring 61 is elastically deformed and rotates about the shaft 62 as a fulcrum.

  Accordingly, when the detector 60 is detected by the suction detection sensor 6 at the timing ta shown in FIG. Here, it is determined that the first sheet P is sucked.

  When the control unit S1 detects that the sheet P is attracted to the conveyance belt 30, the control unit S1 determines that the separation operation timing TS is reached from the output of the suction detection sensor 6, and turns the solenoid SD1 as shown in FIG. By driving, the switching plate 53 is rotated about the support shaft 54 to close the air outlet 52, and the paper P is separated and transported.

  The conveyor belt 30 located on the side facing the sheet placing table 2 is bent at a portion wound around the first driven roller 32, and is formed between the first driven roller 32 and the second driven roller group 33. The conveyance belt 30 positioned therebetween is inclined upward along the conveyance direction of the paper P. As a result, the sheet P adsorbed to the conveyance belt 30 is bent at a portion where the conveyance belt 30 is wound around the first driven roller 32.

  When two or more sheets P are attracted to the conveyor belt 30, a plurality of sheets P are stuck due to electrostatic force or the like. Since the uppermost sheet adsorbed by the conveyance belt 30 is directly attracted by the adsorption air, the conveyance belt 30 is bent in accordance with the portion wound around the first driven roller 32. It becomes a form adsorbed to the conveyor belt 30.

  On the other hand, the second and subsequent sheets that are attached to the uppermost sheet and are adsorbed by the conveyance belt 30 do not directly exert an adsorbing force by adsorbing air. As a result, the second and subsequent sheets do not follow the bent form of the conveyance belt 30 at the portion wound around the first driven roller 32, and the uppermost one sheet and the second and subsequent sheets. Is separated from the tip surface.

  The switching plate 53 closes the air outlet 52 and drives the blower fan 51 of the blower mechanism 5 until it detects that the paper P is sucked on the conveyor belt 30 based on the output of the suction detection sensor 6. Then, the separation air A2 is blown out from the outlet 50. The separation air A <b> 2 blown out from the blowout port 50 is oriented along the conveyance belt 30 on the side facing the sheet placement table 2, and is substantially from the front of the sheet P sucked by the conveyance belt 30 with respect to the sheet P. Sprayed in a horizontal orientation.

  When two or more sheets P are adsorbed by the suction conveyance mechanism 3, the uppermost sheet P1 and the second and subsequent sheets are separated by separation air A2 blown from the front of the sheet P adsorbed to the conveyance belt 30. The paper P2 is separated.

  Thus, the paper P that has floated in a bundle can be spread with the separation air A2, and the sheets other than the topmost sheet adsorbed by the conveyance belt 30 can be separated, thereby preventing the occurrence of double feeding jams during conveyance. Can do.

  In the paper feeding device 1 according to the present embodiment, the air outlet 50 is closed by the switching plate 53 before the paper P is attracted to the transport belt 30, and the air outlet 52 is connected to the switching plate 53 after the paper P is attracted to the transport belt 30. As a result, the floating and separation functions of the paper P can be made compatible. However, the suction detection sensor 6 is configured so that the air outlets 50 and 52 are not completely blocked by the switching plate 53 so that the strength of the airflow of the floating auxiliary air A1 and the separation air A2 blown out by the blower mechanism 5 can be adjusted. Until the adsorption of the paper P is detected, the floating auxiliary air A1 may be blown out with a strong air volume, and when the adsorption detection sensor 6 detects the adsorption of the paper P, it may be switched to a low air volume to blow out the floating auxiliary air A1.

  At time t2 shown in FIG. 6, the output of the suction detection sensor 6 changes to ON at the timing ta and it is detected that the paper P is sucked on the transport belt 30, and as described above, the separation air A2 and This is a separation standby time for separating the paper P by the action of the flying air A3 or the like.

  When the output of the suction detection sensor 6 changes to ON at timing ta and the control unit S1 detects that the paper P has been sucked onto the transport belt 30, the control unit S1 performs the motor at timing tb when a predetermined separation waiting time t2 has elapsed. The drive roller 31 of the suction conveyance mechanism 3 is rotationally driven by M1, and the conveyance roller 37 is rotationally driven by the motor M2, and the conveyance operation of the paper P is started.

  When the driving roller 31 is rotationally driven in the direction indicated by the arrow, the conveying belt 30 rotates, and the side of the conveying belt 30 facing the paper placing table 2 moves in the direction indicated by the arrow F. As a result, the paper P sucked to the transport belt 30 by the suction transport mechanism 3 is fed out in the transport direction indicated by the arrow F. In the transporting operation of the paper P, since the blowing of the separation air A2 by the blower mechanism 5 continues, a force is generated to return the separated second and subsequent papers P toward the paper storage unit 20. This prevents the second sheet P from being transported to the sheet entrance 36 by being tied to the first sheet P.

  When the paper P sucked by the suction transport mechanism 3 is fed out by the transport belt 30, the leading end of the fed paper P enters the detection position of the paper feed detection sensor 39 at timing tc, and the output of the paper feed detection sensor 39. Changes to ON (paper present), and the paper P is detected. Further, after the leading edge of the paper P reaches the paper feed detection sensor 39, when the predetermined time elapses after the feeding by the conveying belt 30 is continued, the leading edge of the paper P is sandwiched between the conveying roller 37 and the driven roller 38.

  The control unit S1 detects that the output of the paper feed detection sensor 39 is turned ON at timing tc and the leading edge of the paper P fed by the transport belt 30 has reached the paper feed detection sensor 39, and then the transport roller 37. When the predetermined waiting time set in consideration of the time until the paper P is nipped by the driven roller 38 elapses, the rotation driving of the conveying belt 30 is stopped. On the other hand, the rotation drive of the conveyance roller 37 continues.

  As a result, the sheet P sandwiched between the transport roller 37 and the driven roller 38 is transported at time t3. In the transport operation of the paper P, the suction operation of the paper P by the suction transport mechanism 3 is continued, and a force for sucking the paper P to the transport belt 30 is working, but the transport roller 37 and the driven roller 38 are sandwiched. The conveyance force due to is stronger than the suction force, and the sheet P is pulled out with the conveyance belt 30 stopped.

  When the paper P sandwiched between the transport roller 37 and the driven roller 38 is transported, the rear end of the paper P passes through the suction detection sensor 6. When the trailing edge of the paper P passes through the suction detection sensor 6, if the paper P is not continuously sucked, the output of the suction detection sensor 6 is turned off by the displacement of the detector 60 constituting the suction detection sensor 6 (no suction). To change.

  When the paper P sandwiched between the transport roller 37 and the driven roller 38 is transported, the rear end of the paper P passes through the paper feed detection sensor 39. When the trailing edge of the paper P passes through the paper feed detection sensor 39, the output of the paper feed detection sensor 39 changes to OFF (no paper).

  When the output of the paper feed detection sensor 39 changes to OFF, the control unit S1 performs control to stop the rotation driving of the transport roller 37. That is, in the transport operation of the paper P, the suction operation of the paper P by the suction transport mechanism 3 is continued, and when the leading end of the preceding paper P reaches the paper feed detection sensor 39, the air outlet provided in the side guide 4 Since the floating air A3 from the blower fan 41 is blown from 40, the second sheet P may be adsorbed to the conveyance belt 30 exposed while the preceding first sheet P is being conveyed. is there. However, as described above, when the leading edge of the first paper P is detected by the paper feed detection sensor 39, the driving of the transport belt 30 is stopped at a predetermined timing, so that the first paper P is transported. The second sheet P adsorbed on the conveyance belt 30 in the middle is not conveyed.

  As a result, at the timing td when the trailing edge of the first sheet P passes through the suction detection sensor 6, the second sheet P is sucked onto the transport belt 30, and the first sheet at timing te. There is a case where the output of the suction detection sensor 6 remains ON (with suction) during the time t4 until the rear end of P passes through the paper feed detection sensor 39 and the output of the paper feed detection sensor 39 is turned OFF. is there.

  In this way, in consideration of the state where the output of the suction detection sensor 6 does not change because the succeeding paper P is continuously sucked by the transport belt 30 as the preceding paper P is transported, the controller S1 By using the outputs of the detection sensor 6 and the paper feed detection sensor 39, the conveyance control by the conveyance belt 30 or the like is performed.

  When the output of the paper feed detection sensor 39 changes to OFF when the output of the suction detection sensor 6 is ON, the control unit S1 waits for a predetermined separation after the output of the paper feed detection sensor 39 changes to OFF. After the elapse of time, the rotational driving of the conveying belt 30 and the conveying roller 37 is started.

  In contrast, when the output of the paper feed detection sensor 39 changes to OFF and the output of the suction detection sensor 6 is OFF, the control unit S1 changes the output of the suction detection sensor 6 to ON. After a predetermined separation waiting time has elapsed, rotation driving of the conveyor belt 30 and the conveyor roller 37 is started.

  In the example shown in FIG. 6, the first sheet P sandwiched between the transport roller 37 and the driven roller 38 is transported, and the trailing edge of the first sheet P passes through the paper feed detection sensor 39 at timing te. When the trailing edge of the first sheet P passes through the sheet feed detection sensor 39 and the output of the sheet feed detection sensor 39 changes to OFF, the process shifts to preparation for feeding the second sheet P. When the output of the paper feed detection sensor 39 changes to OFF, the control unit S1 performs control to stop the rotation driving of the transport roller 37.

  At timing te, since the second sheet P is already attracted to the conveyance belt 30, at time t5, after the output of the paper feed detection sensor 39 changes to OFF at timing te, the operation of the separation air A2 or the like is performed. Is a separation waiting time for separating the paper P.

  The control unit S1 rotates the transport belt 30 and the transport roller 37 at the timing tf when a predetermined separation standby time t5 has elapsed after the first sheet P has passed through the paper feed detection sensor 39, and the two sheets The feeding of the eye paper P is started.

  When the second sheet P attracted to the transport belt 30 is fed out, the output of the paper feed detection sensor 39 changes to ON at the timing tg, and the leading edge of the second paper P reaches the paper feed detection sensor 39. Is detected.

  The control unit S1 detects that the output of the paper feed detection sensor 39 is turned ON at timing tg and the leading edge of the paper P fed by the transport belt 30 has reached the paper feed detection sensor 39, and then the transport roller 37. When the predetermined waiting time set in consideration of the time until the paper P is nipped by the driven roller 38 elapses, the rotation driving of the conveying belt 30 is stopped. On the other hand, the rotation drive of the conveyance roller 37 continues. As a result, the paper P sandwiched between the transport roller 37 and the driven roller 38 is transported at time t6.

  When the paper P sandwiched between the transport roller 37 and the driven roller 38 is transported, the trailing edge of the second paper P passes through the suction detection sensor 6 at timing th. When the trailing edge of the paper P passes through the suction detection sensor 6, if the third paper P is not continuously sucked by the conveyance belt 30, the suction detection sensor 6 is detected by the displacement of the detector 60 that constitutes the suction detection sensor 6. Output changes to OFF (no adsorption). At this time, the trailing edge of the second sheet P does not reach the paper feed detection sensor 39, and the output of the paper feed detection sensor 39 is ON.

  When the second sheet P sandwiched between the transport roller 37 and the driven roller 38 is further transported, the trailing edge of the second sheet P passes through the paper feed detection sensor 39 at timing ti. When the trailing edge of the paper P passes through the paper feed detection sensor 39, the output of the paper feed detection sensor 39 changes to OFF.

  When the second paper P passes through the paper feed detection sensor 39 and the output of the paper feed detection sensor 39 changes to OFF, the control unit S1 shifts to preparation for feeding the third paper P. When the output of the paper feed detection sensor 39 changes to OFF, the control unit S1 performs control to stop the rotation driving of the transport roller 37.

  When the second sheet P passes through the suction detection sensor 6, the suction operation by the suction transport mechanism 3 continues, and the switching plate 53 that drives the solenoid SD <b> 1 to close the outlet 52 opens the outlet 50. It is made to close. Then, the floating auxiliary air A <b> 1 is blown out from the air outlet 52, so that the third sheet P is floated and is adsorbed by the conveyance belt 30. Times t <b> 7 and t <b> 8 are levitation / adsorption waiting times for waiting for the third sheet P to be adsorbed to the conveyance belt 30 after the second sheet P passes through the adsorption detection sensor 6.

  When the third sheet P is attracted to the transport belt 30 at the timing tj, the detector 60 is detected by the suction detection sensor 6, and the output of the suction detection sensor 6 is changed to ON (with suction). The control unit S1 determines that the paper P is attracted to the transport belt 30.

  When the output of the paper feed detection sensor 39 is OFF and the output of the suction detection sensor 6 is turned ON, the control unit S1 drives the solenoid SD1 to close the air outlet 50 and closes the air outlet 52. Thus, the process proceeds to the separation and transport operation of the third sheet P.

  The controller S1 adsorbs the third sheet P to the conveyance belt, and at the timing tk when a predetermined separation waiting time t9 has elapsed after the output of the adsorption detection sensor 6 is turned ON. 30 and the conveyance roller 37 are rotationally driven to start feeding the third sheet P. Thereafter, the above process is repeated.

  Thus, in the operation example of the first mode in which the auxiliary side guide 43 is not used, when the suction detection sensor 6 is OFF (no suction), the sheet P is reliably lifted in addition to the floating air A3 from the air outlet 40. In order to prevent this, the flying auxiliary air A1 is blown from the air outlet 52 to the front end surface of the paper P. As a result, the sheet feeding device 1 can prevent the occurrence of unsucked jam.

  Next, an operation example of the paper feeding device 1 when it is assumed that the auxiliary side guide 43 is used will be described. Components having the same names and reference numerals as those in the description of FIGS. 5 and 6 have the same functions, and thus description thereof is omitted.

  When the auxiliary side guide 43 is used, the control unit S1 operates the sheet feeding device 1 in the second mode in which the auxiliary side guide 43 is used from the output of the auxiliary side guide sensor 44. As shown in FIG. 7, in the second mode, when the paper feed detection sensor 39 is OFF and when the suction detection sensor 6 is OFF, the air outlet 50 is blocked by the switching plate 53 and floats from the air outlet 52. The auxiliary air A1 is blown onto the paper P. Thereby, even when the suction detection sensor 6 is ON at the timing td, the air outlet 50 is blocked by the switching plate 53 and air is blown from the air outlet 52 to the leading end surface of the paper P in order to float the air blowing mechanism 5. The amount of air that is not sufficient with the floating air A3 alone can be compensated. By using the auxiliary side surface guide 43, even if the distance between the air outlet 40 of the side surface guide 4 and the paper is large, even a small size paper such as A6, B6 size, postcard size, etc., can be surely lifted to attract the suction surface 30b. Can be absorbed.

  As described above, in the second mode operation example using the auxiliary side guide 43 shown in FIG. 7, the sheet P is floated when the paper feed detection sensor 39 is OFF and when the suction detection sensor 6 is OFF. Therefore, in addition to blowing the flying air A3 from the air outlet 40 to the side surface of the paper P, the air assisting air A1 is blown from the air outlet 52 to the leading end surface of the paper P. As a result, the sheet feeding device 1 can prevent the occurrence of unsucked jam.

  According to the paper feeding device 1 according to the present invention, air is blown from the front end surface of the paper P loaded on the paper placing table 2 until the paper P is attracted to the suction surface 30b. Therefore, the sheet P can be reliably lifted and sucked on the suction surface 30b. Thereby, it is possible to prevent a suction failure in which the paper P is not sucked by the suction surface 30b.

  In addition, after the sheet P is adsorbed to the adsorption surface 30b, air is blown from the front end surface of the sheet P adsorbed to the adsorption surface 30b, and when a plurality of sheets P float, A plurality of sheets P can be passed through the sheet P, and the sheets other than the uppermost sheet adsorbed on the adsorption surface 30b can be separated regardless of the size of the sheet P. Thereby, it is possible to prevent the occurrence of double feeding in which a plurality of sheets P are conveyed while being attracted to the attracting surface 30b.

  In the present embodiment, in the first mode, when the suction detection sensor 6 does not detect the paper P, the switching mechanism 55 is driven so that air is blown from the outlet 52 to the front end surface of the paper. However, air may be blown from the outlet 50 to the front end of the paper P adsorbed on the adsorption surface 30b.

<Configuration Example of Paper Feed Unit 90>
Next, the paper feeding unit 90 provided with the paper feeding device 1 according to the present invention will be described.
As shown in FIG. 8, the sheet feeding unit 90 includes three sheet trays P220, P221, and P222 in the vertical direction as an example in the present embodiment. Further, on each of the paper trays P220, P221, and P222, a suction conveyance mechanism 3 having the conveyance belt 30 shown in FIG. Further, floating air is blown to the sides of the paper trays P220, P221, and P222 from the air outlet 40 on the side surface of the paper P stacked on the paper trays P220, P221, and P222, and the width direction of the paper P is maintained. A side guide 4 is provided. The side guide 4 is provided with an auxiliary side guide 43. The auxiliary side surface guide 43 can be protruded by rotating to the side surface of the paper P, and can support the side surface of the paper having a narrower width than the paper supported by the side surface guide 4.

  When the auxiliary air for flying is blown from the air outlet 52 at the front end surface of the paper P stacked on the paper trays P220, P221, and P222, and two or more papers P are adsorbed by the adsorbing and conveying mechanism 3, The blower mechanism 5 for blowing the separation air between the first sheet and the second and subsequent sheets is provided.

  The paper trays P220, P221, and P222 are provided so that they can be pulled out in the front-rear direction of the drawing by opening a front door (not shown) provided on the front side of the drawing. The front surface of the paper tray can be configured as an exterior plate, and a handle or the like that can be put on the exterior plate can be provided, and the paper tray can be pulled out and pushed in using the handle or the like.

  The paper feeding direction of the paper P by the suction conveyance mechanism 3 is a direction (left direction in the drawing) orthogonal to the drawing direction of the paper trays P220, P221, and P222.

  The sheet P adsorbed to the conveyance belt 30 by the adsorption conveyance mechanism 3 is floating air blown from the blowout ports 40 and 52, floating auxiliary air blown from the blowout port 52, separation air blown from the blowout port 50, and the like. It is separated into one sheet by the action of. The sheet P fed from the sheet tray P220 by the suction conveyance mechanism 3 has a nip portion at substantially the same height as the lower surface of the conveyance belt 30 wound around the lower driven rollers of the second driven roller group 33 shown in FIG. Is sandwiched between a pair of conveying rollers 37 and a driven roller 38.

  The paper P sandwiched between the transport roller 37 and the driven roller 38 is transported by the transport roller 37 and the transport direction is changed downward by the action of the guide member. Next, the paper is transported downward by the transport rollers R223 to R226 constituting the vertical paper transport path, guided in the substantially horizontal direction on the left side of the drawing by the guide member, and then contacted with the transport roller R227 in the rotation stopped state. Stop in contact. Thereafter, the sheet P is fed into the image forming apparatus with the start of rotation of the transport roller 227 and the like. The transport roller R227 functions as a registration roller for timing with an image forming process in the image forming apparatus 100 described later.

  Similarly, the sheet P fed from the sheet tray P221 by the suction conveyance mechanism 3 is substantially the same height as the lower surface of the conveyance belt 30 wound around the lower driven rollers of the second driven roller group 33 shown in FIG. Are sandwiched between a pair of conveying rollers 37 and a driven roller 38 having a nip portion.

  The paper P sandwiched between the transport roller 37 and the driven roller 38 is transported by the transport roller 37 and the transport direction is changed downward by the action of the guide member. Next, after being transported downward by the transport rollers R225 and R226 and guided in a substantially horizontal direction on the left side of the drawing by the guide member, the transport roller R227 is stopped by abutting the leading end against the transport roller R227 in a rotation stopped state. It is sent into the image forming apparatus with the start of rotation.

  Further, the sheet P fed out from the sheet tray P222 by the suction conveyance mechanism 3 is substantially the same height as the lower surface of the conveyance belt 30 wound around the lower driven rollers of the second driven roller group 33 shown in FIG. It is sandwiched between a pair of conveying rollers 37 and a driven roller 38 having a nip portion.

  The paper P sandwiched between the transport roller 37 and the driven roller 38 is transported by the transport roller 37 and stopped with the leading end in contact with the transport roller R227 in a rotation stopped state, and as the transport roller R227 starts rotating. It is sent into the image forming apparatus.

  According to the paper feeding unit 90 according to the present invention, since the above-described paper feeding device 1 is provided, it is possible to prevent suction failure in which the paper P is not attracted to the suction surface, and a state in which a plurality of sheets P are attracted to the suction surface. Can prevent double feeding.

<Configuration Example of Image Forming Apparatus 100>
Next, the image forming apparatus 100 including the paper feeding device 1 according to the present invention will be described.
As shown in FIG. 9, the image forming apparatus 100 is, for example, a digital color copying machine, and includes an image forming unit 104 and an image reading apparatus 101. The image forming apparatus 100 further includes a paper feeding unit 80, a fixing unit 77, and a control unit S. The image forming unit 104 is referred to as a tandem color image forming unit, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K and a transfer unit 70.

  The image reading apparatus 101 includes an automatic document feeder 102 and a scanning exposure apparatus 103, and is installed on the upper part of the image forming unit 104. The document 7 placed on the document table of the automatic document feeder 102 is transported by a transport unit (not shown), and an image on one or both sides of the document 7 is scanned and exposed by the optical system of the scanning exposure device 103. And the like are read into the line image sensor 8 constituted by the above. The image data photoelectrically converted by the line image sensor 8 is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in an image processing unit (not shown), and then exposure units 3Y, 3M, 3C, 3K. Sent to.

  An image forming unit 10Y that forms a yellow (Y) image includes a charging unit 2Y, an exposure unit 3Y, a developing unit 4Y, a primary transfer unit 5Y, and a cleaning unit 6Y around a cylindrical photosensitive drum 1Y. An image forming unit 10M that forms a magenta (M) color image includes a charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer unit 5M, and a cleaning unit 6M around a cylindrical photosensitive drum 1M. An image forming unit 10C for forming a cyan (C) color image includes a charging unit 2C, an exposure unit 3C, a developing unit 4C, a primary transfer unit 5C, and a cleaning unit 6C around a cylindrical photosensitive drum 1C. An image forming unit 10K that forms a black (K) image includes a charging unit 2K, an exposure unit 3K, a developing unit 4K, a primary transfer unit 5K, and a cleaning unit 6K around a cylindrical photosensitive drum 1K. When color image data is input to the image forming apparatus 100, toner images of the respective colors are formed from the image forming units 10Y, 10M, 10C, and 10K. When monochrome image data is input to the image forming apparatus 100, the image forming unit. A black toner image is formed from 10K.

  The transfer unit 70 includes an intermediate transfer belt 71, a secondary transfer unit 72, a driving roller 73, and a belt cleaning unit 74.

  The intermediate transfer belt 71 is wound around a plurality of rollers including a driving roller 73 and is rotatably supported. The photosensitive drums 1Y, 1M, 1C, and 1K and the primary transfer portions 5Y, 5M, 5C, and 5K press the intermediate transfer belt 71. The toner images formed on the photoreceptor drums 1Y, 1M, 1C, and 1K are sequentially transferred to the intermediate transfer belt 71, and a toner image is formed on the intermediate transfer belt 71.

  The paper feed unit 80 includes paper trays P10, P11, and P12, the paper feed device 1 described above, a paper feed roller 81, a registration roller 82, and the like. The sheets P accommodated in the sheet trays P10, P11, and P12 are separated one by one by the sheet feeding device 1 provided in the sheet feeding unit 80, pass through the sheet feeding roller 81, and the registration roller 82 in a stopped state. Paper is fed to The sheet P is temporarily stopped by the registration roller 82, and the registration roller 82 starts to rotate at the timing when the position of the leading end of the sheet P and the toner image formed on the intermediate transfer belt 71 coincide with each other. The paper P is fed and a toner image is transferred onto the paper P. After the toner image is transferred to the paper P by the secondary transfer unit 72, the residual toner adhering to the intermediate transfer belt 71 is removed by the belt cleaning unit 74.

  The fixing unit 77 includes a fixing roller 78 and a pressure roller 79. The sheet P onto which the toner image has been transferred is heated and pressed on the image formed on the sheet P at the nip formed between the fixing roller 78 and the pressure roller 79 so that the toner image is formed on the sheet P. It is fixed. Thereafter, the paper P is sandwiched between the paper discharge rollers 83 and placed on the paper discharge tray 84 outside the apparatus.

  The control unit S includes a CPU that performs arithmetic control processing, a ROM that stores various programs, a RAM that stores various data, and the like, and performs all controls such as control related to a series of image forming processes. The control unit S controls the switching mechanism 55 of the paper feeding device 1 based on the outputs of the suction detection sensor 6, the paper feed detection sensor 39, and the auxiliary side surface guide sensor 44 described with reference to FIG.

  According to the image forming apparatus 100 according to the present invention, since the above-described paper feeding device 1 is provided, it is possible to prevent a suction failure in which the paper P is not attracted to the suction surface, and a state in which a plurality of sheets P are attracted to the suction surface. Can prevent double feeding and improve image quality.

  Although the above is an image forming apparatus that forms a color image, an image forming apparatus that forms a monochrome image may be used.

<Configuration Example of Image Forming Unit 110>
Next, the image forming unit 110 including the image forming apparatus 100 and the paper feeding unit 90 according to the present invention will be described.
As shown in FIG. 10, the image forming unit 110 includes an image forming apparatus 100 and a paper feeding unit 90.

  The sheets separated and discharged one by one by the sheet feeding unit 90 shown in FIG. 8 are conveyed to the communication port 9. An image forming apparatus 100 is connected to the communication port 9. The image forming apparatus 100 receives the sheet conveyed to the communication port 9, performs various image forming processes, and then places the sheet on a discharge tray outside the apparatus. The

  According to the image forming unit 110 according to the present invention, since the above-described paper feeding unit 90 and the image forming apparatus 100 are provided, it is possible to prevent a suction failure in which a sheet is not attracted to the suction surface, and a plurality of sheets are attracted to the suction surface. Therefore, it is possible to prevent the double feeding that is conveyed in the state of being performed and to improve the image quality.

  The present invention is extremely suitable when applied to an image forming apparatus provided with a paper feeding device that floats loaded paper with air and sucks it on a conveyor belt or the like.

  DESCRIPTION OF SYMBOLS 1 ... Paper feeder, 2 ... Paper mounting stand, 3 ... Adsorption conveyance mechanism, 4 ... Side guide, 5 ... Floating / separation air blowing mechanism, 6 ... Adsorption detection sensor, DESCRIPTION OF SYMBOLS 20 ... Paper storage part, 22 ... Upper limit detection sensor, 30 ... Conveyor belt, 40 ... Floating air outlet, 41, 51 ... Blower fan, 43 ... Auxiliary side guide, 44 ... Auxiliary side guide sensor, 50 ... Separate air outlet, 52 ... Floating auxiliary air outlet, 53 ... Switching plate, 55 ... Switching mechanism, 90 ... Paper feeding unit, 100 ... Image forming apparatus, 110 ... Image forming unit

Claims (5)

A paper mounting table on which a plurality of paper sheets are stacked and moved up and down along the paper stacking direction;
A first side end holding member that is movable in a width direction orthogonal to a paper transport direction and holds a side surface of the paper stacked on the paper mounting table;
The first side end holding member is provided in the first side end holding member so as to be freely projectable in the moving direction of the first side end holding member, and holds a side surface of a paper having a narrower width than the paper held by the first side end holding member. Two side end holding members;
A suction surface for adsorbing the uppermost sheet, and the sheet held on the side by the first or second side edge holding member is sucked from the upper surface to be sucked to the suction surface and sucked to the suction surface. A suction transport mechanism for transporting the used paper to the paper transport path;
A front end surface of a sheet having a first air outlet and a second air outlet provided above the first air outlet, and loaded on the sheet mounting table from the first air outlet. A blower mechanism that blows air onto the front end surface of the paper adsorbed on the suction surface from the second air outlet;
A switching mechanism that is provided between the blower mechanism and the first and second air outlets, and switches the distribution of the amount of air blown from the first and second air outlets;
An adsorption detection sensor for detecting whether or not a sheet is adsorbed on the adsorption surface;
A paper feed detection sensor for detecting paper conveyed by the suction conveyance mechanism;
Based on whether or not the sheet is attracted to the suction surface detected by the suction detection sensor, the sheet conveyance position detected by the paper feed detection sensor, and whether or not the second side end holding member is in a protruding state. Control for driving the switching mechanism by determining a floating operation timing for floating the paper loaded on the paper mounting table and a separation operation timing for separating the paper sucked on the suction surface by the suction conveyance mechanism A sheet feeding device. The case where the second side end holding member is not in a protruding state is a first mode,
When the second mode is a case where the second side end holding member is in a protruding state,
The controller is
In the first mode, when the suction detection sensor does not detect the paper, the switching mechanism is driven to blow air from the first air outlet to the front end surface of the paper, and the suction detection sensor When the suction of the paper is detected, the switching mechanism is driven to blow air from the second air outlet to the front end of the paper sucked on the suction surface,
In the second mode, when the suction detection sensor does not detect the paper, the switching mechanism is driven to blow air from the first air outlet to the front end surface of the paper, and the suction detection sensor Detects the suction of the paper and drives the switching mechanism during a period when the paper feed detection sensor does not detect the paper, and the leading edge of the paper sucked to the suction surface from the second air outlet Air is blown to the sheet, and the switching mechanism is driven during a period in which the suction detection sensor detects the suction of the paper and the paper feed detection sensor detects the paper. The paper feeding device according to claim 1, wherein air is blown to the front end surface. One or more paper trays in which paper is stored;
A plurality of sheets stacked on the sheet tray, and a sheet placing table that moves up and down along the sheet stacking direction;
A first side end holding member that is movable in a width direction orthogonal to a paper transport direction and holds a side surface of the paper stacked on the paper mounting table;
The first side end holding member is provided in the first side end holding member so as to be freely projectable in the moving direction of the first side end holding member, and holds a side surface of a paper having a narrower width than the paper held by the first side end holding member. Two side end holding members;
A suction surface for adsorbing the uppermost sheet, and the sheet held on the side by the first or second side edge holding member is sucked from the upper surface to be sucked to the suction surface and sucked to the suction surface. A suction transport mechanism for transporting the used paper to the paper transport path;
A front end surface of a sheet having a first air outlet and a second air outlet provided above the first air outlet, and loaded on the sheet mounting table from the first air outlet. A blower mechanism that blows air onto the front end surface of the paper adsorbed on the suction surface from the second air outlet;
A switching mechanism that is provided between the blower mechanism and the first and second air outlets, and switches the distribution of the amount of air blown from the first and second air outlets;
An adsorption detection sensor for detecting whether or not a sheet is adsorbed on the adsorption surface;
A paper feed detection sensor for detecting paper conveyed by the suction conveyance mechanism;
Based on whether or not the sheet is attracted to the suction surface detected by the suction detection sensor, the sheet conveyance position detected by the paper feed detection sensor, and whether or not the second side end holding member is in a protruding state. Control for driving the switching mechanism by determining a floating operation timing for floating the paper loaded on the paper mounting table and a separation operation timing for separating the paper sucked on the suction surface by the suction conveyance mechanism A sheet feeding unit. An image forming unit for forming an image on paper;
A paper mounting table on which a plurality of paper sheets are stacked and moved up and down along the paper stacking direction;
A first side end holding member that is movable in a width direction orthogonal to a paper transport direction and holds a side surface of the paper stacked on the paper mounting table;
The first side end holding member is provided in the first side end holding member so as to be freely projectable in the moving direction of the first side end holding member, and holds a side surface of a paper having a narrower width than the paper held by the first side end holding member. Two side end holding members;
A suction surface for adsorbing the uppermost sheet, and the sheet held on the side by the first or second side edge holding member is sucked from the upper surface to be sucked to the suction surface and sucked to the suction surface. A suction conveyance mechanism for conveying the formed paper to the image forming unit;
A front end surface of a sheet having a first air outlet and a second air outlet provided above the first air outlet, and loaded on the sheet mounting table from the first air outlet. A blower mechanism that blows air onto the front end surface of the paper adsorbed on the suction surface from the second air outlet;
A switching mechanism that is provided between the blower mechanism and the first and second air outlets, and switches the distribution of the amount of air blown from the first and second air outlets;
An adsorption detection sensor for detecting whether or not a sheet is adsorbed on the adsorption surface;
A paper feed detection sensor for detecting paper conveyed by the suction conveyance mechanism;
Based on whether or not the sheet is attracted to the suction surface detected by the suction detection sensor, the sheet conveyance position detected by the paper feed detection sensor, and whether or not the second side end holding member is in a protruding state. Determining a floating operation timing for floating the paper loaded on the paper mounting table and a separation operation timing for separating the paper sucked on the suction surface by the suction conveyance mechanism, and driving the switching mechanism, An image forming apparatus comprising: a control unit that performs control to form an image in the image forming unit. An image forming unit for forming an image on paper;
A paper feeding device for feeding paper to the image forming unit;
A control unit that performs control of supplying a sheet from the sheet feeding device to the image forming unit and forming an image in the image forming unit;
The paper feeder is
A paper mounting table on which a plurality of paper sheets are stacked and moved up and down along the paper stacking direction;
A first side end holding member that is movable in a width direction orthogonal to a paper transport direction and holds a side surface of the paper stacked on the paper mounting table;
The first side end holding member is provided in the first side end holding member so as to be freely projectable in the moving direction of the first side end holding member, and holds a side surface of a paper having a narrower width than the paper held by the first side end holding member. Two side end holding members;
A suction surface for adsorbing the uppermost sheet, and the sheet held on the side by the first or second side edge holding member is sucked from the upper surface to be sucked to the suction surface and sucked to the suction surface. A suction transport mechanism for transporting the used paper to the paper transport path;
A front end surface of a sheet having a first air outlet and a second air outlet provided above the first air outlet, and loaded on the sheet mounting table from the first air outlet. A blower mechanism that blows air onto the front end surface of the paper adsorbed on the suction surface from the second air outlet;
A switching mechanism that is provided between the blower mechanism and the first and second air outlets, and switches the distribution of the amount of air blown from the first and second air outlets;
An adsorption detection sensor for detecting whether or not a sheet is adsorbed on the adsorption surface;
A paper feed detection sensor for detecting paper conveyed by the suction conveyance mechanism,
The controller is
Based on whether or not the sheet is attracted to the suction surface detected by the suction detection sensor, the sheet conveyance position detected by the paper feed detection sensor, and whether or not the second side end holding member is in a protruding state. Determining the floating operation timing for floating the paper loaded on the paper mounting table and the separation operation timing for separating the paper sucked on the suction surface by the suction conveyance mechanism, and driving the switching mechanism. An image forming unit.

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