Patent Publication Number: US-11643292-B2

Title: Sheet feeding device

Description:
FIELD OF THE INVENTION AND RELATED ART 
     The present invention relates to a sheet feeding device for feeding (conveying) a sheet. 
     Conventionally, as disclosed in Japanese Laid-Open Patent Application Hei 11-189355, a sheet alignment means for correcting oblique movement of the sheet on a side registration basis has been proposed. This sheet alignment means causes a side end of the sheet fed (conveyed) by a feeding portion and a feeding roller pair, to abut against an abutment member by an obliquely feeding roller pair. 
     In the case where a long sheet, for example, an elongated sheet with respect to a sheet feeding direction in which the sheet is fed, is fed, the sheet is fed in some instances in a state in which a nip of each of the obliquely feeding roller pair and the feeding roller pair is separated. 
     Further, in order to adjust a variation in position of a leading end of the sheet fed, on a side upstream of a registration roller pair, feeding of the sheet is once stopped and then is resumed at predetermined timing. 
     However, in the case where the feeding of the sheet is once stopped on the side upstream of the registration roller pair and then the sheet is fed again, there is a liability that a slip occurs between the feeding portion and the sheet. In this case, there is a liability that the sheet cannot be fed to the registration roller pair and thus improper feeding such as non-feeding of the sheet or the like occurs. 
     SUMMARY OF THE INVENTION 
     A principal object of the present invention is to provide a sheet feeding device capable of reducing a degree of oblique movement of a sheet and a degree of improper feeding of the sheet. 
     According to an aspect of the present invention, there is provided a sheet feeding device comprising: a sheet supporting portion configured to support a sheet; a side end regulating portion configured to regulate a side end of the sheet supported by the sheet supporting portion; a feeding portion configured to feed the sheet supported by the supporting portion and regulated by the regulating portion; a first feeding roller pair configured to feed the sheet fed by the feeding portion, in a sheet feeding direction; an abutment member which is provided downstream of the first feeding roller pair with respect to the sheet feeding direction, which extends in the sheet feeding direction, and against which a side end of the sheet with respect to a widthwise direction of the sheet is abutted; an obliquely feeding roller pair configured to obliquely feed the sheet in an inclination direction relative to the sheet feeding direction so that the sheet approaches the abutment member in the widthwise direction; a second feeding roller pair provided downstream of the obliquely feeding roller pair with respect to the sheet feeding direction and configured to feed the sheet; a first contact-and-separation mechanism configured to contact and separate the first feeding roller pair so as to be changeable between a first feedable state in which the first feeding roller pair is capable of feeding the sheet while nipping the sheet and a first separated state in which rollers of the first feeding roller pair are in separation from each other; a second contact-and-separation mechanism configured to contact and separate the obliquely feeding roller pair so as to be changeable between a second feedable state in which the obliquely feeding roller pair is capable of feeding the sheet while nipping the sheet and a second separated state in which rollers of the obliquely feeding roller pair are in separation from each other, wherein when the sheet fed has a first length, feeding of the sheet is stopped after the sheet is fed to an upstream side of the second feeding roller pair by the feeding portion in a state in which the first feeding roller pair is put in the first separated state by the first contact-and-separation mechanism, and then is resumed in a state in which the first feeding roller pair is changed from the first separated state to the first feedable state and in a state in which the obliquely feeding roller pair is put in the second separated state by the second contact-and-separation mechanism, and then the sheet is fed to the second feeding roller pair, and wherein when the sheet fed has a second length shorter than the first length, the sheet fed by the first feeding roller pair is obliquely fed by the obliquely feeding roller pair in the second feedable state and then is fed to the second feeding roller pair. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a sectional view showing entirety of an image forming apparatus in an embodiment of the present invention. 
         FIG.  2    is a (top) plan view showing a sheet alignment portion in the embodiment. 
         FIG.  3    is a perspective view showing a feeding roller pair and a peripheral structure thereof in the embodiment. 
       Part (a) of  FIG.  4    is a sectional view showing a contact state of the feeding roller pair in the embodiment, and part (b) of  FIG.  4    is a sectional view showing a spaced state of the feeding roller pair in the embodiment. 
         FIG.  5    is a plan view showing an obliquely feeding roller pair and a peripheral structure thereof in the embodiment. 
       Part (a) of  FIG.  6    is a perspective view showing the obliquely feeding roller pair and a contact-and-separation mechanism in a contact state in the embodiment, and part (b) of  FIG.  6    is a side view showing the obliquely feeding roller pair and the contact-and-separation mechanism in the contact state in the embodiment. 
         FIG.  7    is a block diagram showing a control system of the image forming apparatus in the embodiment. 
         FIG.  8    is a schematic view of a manual feeding portion in the embodiment. 
         FIG.  9    is a plan view showing a sheet supporting portion in the embodiment. 
         FIG.  10    is a perspective view showing the sheet supporting portion in the embodiment. 
         FIG.  11    is a perspective view showing entirety of the sheet supporting portion when an elongated sheet is supported by the sheet supporting portion in the embodiment. 
         FIG.  12    is a flowchart showing feeding control of the sheet in the embodiment. 
         FIG.  13    is a flowchart showing feeding control of the sheet in the embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Embodiments of the present invention will be specifically described with reference to the drawings. Dimensions, materials, shapes and relative arrangement of constituent elements described in the following embodiments should be appropriately be changed depending on structures and various conditions of apparatuses (devices) to which the present invention is applied, and the scope of the present invention is not intended to the limited thereto. 
     [General Structure] 
     An image forming apparatus  1  in an embodiment of the present invention is a full-color laser (beam) printer of an intermediary tandem type in which an intermediary transfer belt  506  as shown in  FIG.  1   . The image forming apparatus  1  of this type does not need to hold a sheet on a transfer drum or a transfer belt, and therefore, it is possible to meet various transfer materials such as super-thick paper and coated paper, and in addition, the image forming apparatus  1  is suitable for realizing high productivity since the image forming apparatus  1  has advantages such as parallel processing in a plurality of image forming portions and collective transfer of color toner images for a full-color image. 
     The image forming apparatus  1  forms an image on a sheet P on the basis of an image signal inputted from an information terminal such as a personal computer or from an external device such as an image reader. The image forming apparatus  1  is capable of using, as a recording material (medium), various sheets including paper such as a form or an envelope, glossy paper, a plastic film such as an overhead projector (OHP) sheet, a cloth and the like. 
     The image forming apparatus  1  includes a sheet feeding (conveying) system described later and an image forming portion  80 . The image forming portion  80  includes four process units PY, PM, PC and PK for forming toner images of yellow, magenta, cyan and black, respectively and the intermediary transfer belt  506  which is an intermediary transfer member. Each of the process units PY to PK is an electrophotographic unit including a photosensitive drum which is a photosensitive member. 
     The process units PY to PK are similarly constituted except that colors of toners used for development are different from each other, and therefore, a structure and a toner image forming process (image forming operation) of the process units will be described by using the process unit PY as an example. The process unit PY includes, in addition to a photosensitive drum  508 , an unshown charging device, an exposure device  511 , a developing device  510  and a drum cleaner  509 . The photosensitive drum  508  is a drum-shaped photosensitive member including a photosensitive layer at an outer peripheral portion and rotates in an arrow A direction along a rotational direction of the intermediary transfer belt  506 . A surface of the photosensitive drum  508  is electrically charged by being supplied with electric charges from the charging device  2 . 
     The exposure device  511  emits laser light modulated depending on image information, so that the surface of the photosensitive drum  508  is scanned with the laser light appropriately through a diffraction means  512  or the like, and thus an electrostatic latent image is formed on the surface of the photosensitive drum  508 . The developing device  510  accommodates a developer containing the toner and develops the electrostatic latent image into a toner image by supplying the toner to the surface of the photosensitive drum  508 . The toner image formed on the photosensitive drum  508  is primary-transferred onto the intermediary transfer belt  506  at a primary transfer portion which is a nip between the intermediary transfer belt  506  and a primary transfer roller  507  which is a primary transfer device. Residual toner remaining on the photosensitive drum  508  after the transfer is removed by the drum cleaner  509 . 
     The intermediary transfer belt  506  is extended and wound around a driving roller  504 , a tension roller  505  and an inner secondary transfer roller  503  and the like, and is rotationally driven in an arrow B direction in  FIG.  1    by the driving roller  504 . The image forming operation described above is performed in the process units PY to PK in parallel, and the four color toner images are transferred so as to be superposed on each other, so that a full-color toner image is formed on the intermediary transfer belt  506 . These toner images are fed to a secondary transfer portion by being carried on the intermediary transfer belt  506 . The secondary transfer portion is constituted as a nip as a transfer portion between a secondary transfer roller  56  and the inner secondary transfer roller  503 , and the toner image is secondary-transferred onto the sheet S under application of a bias voltage, to the secondary transfer roller  56 , of a polarity opposite to a charge polarity of the toner. Residual toner remaining on the intermediary transfer belt  506  after the transfer is removed by a belt cleaner. 
     The sheet S on which the toner image is transferred is delivered to a fixing unit  58  by a pre-fixing feeding portion  57 . The fixing unit  58  includes a fixing roller pair for feeding the sheet S while nipping the sheet S and a heat source such as a halogen heater, and applies heat and pressure to the toner image carried on the sheet S. By this, toner particles are melted and fixed, so that an image fixed on the sheet S is obtained. 
     Next, a structure and an operation of a sheet feeding system for feeding the sheet S and for discharging the sheet S, on which the image is formed, onto a discharge tray  500  will be described. The sheet feeding system roughly includes a cassette feeding portion  70 , a merging feeding portion  54 , a manual feeding device  40 , a first feeding portion  50 , a second feeding portion  55 , a registration roller pair  7 , a branch feeding portion  59 , a reverse feeding portion  501  and a double-side feeding portion  502 . 
     The cassette feeding portion  70  includes a feeding cassette  51  for accommodating sheets S, a sheet stacking portion  52  which is provided in the feeding cassette  51  and on which the sheets S are stacked, and a feeding device  53 . The feeding device  53  not only attracts and separates an uppermost sheet stacked on the sheet stacking portion  52 , by the air, but also feeds the uppermost sheet. Incidentally, the feeding device  53  is not limited to the feeding device  53  of such an air separation type but may also be of a type in which the sheet S is separated by an electrostatic force or of a friction separation type in which the sheet S is separated by a feeding roller or a separation roller or the like. 
     The sheet S fed by the feeding device  53  and the sheet S fed by the manual feeding device  40  described later are fed to the first feeding portion  50  through the merging feeding portion  54 . Then, the sheet S fed in a sheet feeding direction VD by the first feeding portion  50  is subjected to correction of oblique movement in the second feeding portion  55 , and then is fed to the registration roller pair  7 . The registration roller pair  7  is capable of sliding the sheet S in a widthwise direction WD (see  FIG.  2   ) perpendicular to the sheet feeding direction VD while nipping and conveying the sheet S. By this, a position of the sheet S with respect to the widthwise direction WD is corrected. 
     Then, the sheet S is fed by the registration roller pair  7  on the basis of detection timing thereof by a registration sensor  8  so as to be synchronized with transfer timing at the secondary transfer portion. The sheet S on which the toner image is transferred in the secondary transfer portion and on which the image is fixed by the fixing unit  58  is fed to the branch feeding portion  59  including an unshown switching member capable of switching a feeding passage of the sheet S. In the case where the image formation on the sheet S is completed, the sheet S is discharged onto the discharge tray  500 . 
     In the case where the image is formed on a back surface (side) of the sheet P, the sheet P is delivered to the double-side feeding portion  502  through the reverse feeding portion  501 . The reverse feeding portion  501  includes a reverse roller pair capable of being rotated normally and reversely and subjects the sheet S to switch-back, and then delivers the sheet S to the double-side feeding portion  502 . The double-side feeding portion  502  feeds the sheet S toward the merging feeding portion  54  through a double-side feeding path  54   b  merging with a feeding path  54   a . At the merging feeding portion  54 , the feeding path  54   a  and the double-side feeding path  54   b  merge with each other. Then, the image is formed on the back surface of the sheet S, and then the sheet S is discharged onto the discharge tray  500 . 
     Incidentally, a sheet feeding device  700  according to this embodiment includes the manual feeding device  40 , the first feeding portion  50 , the second feeding portion  55 , the registration roller pair  7  and a controller  600  (see  FIG.  7   ). Further, in addition to the above-described constitution, the image forming portion  80  is included, so that the image forming apparatus  1  may also be used as the sheet feeding device. 
     [Sheet Aligning Portion] 
     A sheet aligning portion  90  constituted by the first feeding portion  50 , the second feeding portion  55  and the registration roller pair  7  and the like will be described. As shown in  FIG.  2   , with respect to the sheet feeding direction VD, the second feeding portion  55  is provided downstream of the first feeding portion  50 , and the registration roller pair  7  as a second feeding roller pair is provided downstream of the second feeding portion  55 . 
     The first feeding portion  50  includes feeding roller pairs  341 ,  342 ,  343  and  344 , which are first feeding roller pairs, provided in a named order from an upstream side toward a downstream side with respect to the sheet feeding direction VD. The second feeding portion  55  includes a reference member  31  which is an abutment member extending along the sheet feeding direction VD, and includes three obliquely feeding rollers  35 ,  36  and  37  provided with intervals with respect to the sheet feeding direction VD. 
     A sheet feeding direction of the obliquely feeding rollers is inclined relative to a reference surface  31   a  of the reference member  31  by an angle α. Therefore, the obliquely feeding roller  35 ,  36  and  37  rotate in contact with the sheet S and impart a feeding force to the sheet S in a direction in which the sheet S is inclined so as to approach the reference surface  31   a  of the reference member  31  with respect to the widthwise direction WD as the sheet S is fed toward a downstream side of the sheet feeding direction VD. 
     The registration roller pair  7  is slidable in the widthwise direction WD in a state in which the registration roller pair  7  nips the sheet S, and moves the sheet S having a side end contacted to the reference surface  31   a  of the reference member  31  in the widthwise direction WD in conformity to a position of the image transferred in the secondary transfer portion. Incidentally, the reference member  31  is movable in the widthwise direction WD and is positioned in advance in conformity to a width of the sheet S fed. Further, a method in which positional adjustment of the sheet S and the image to be formed on the sheet S is not limited thereto, and for example, a constitution in which a position of the reference member  31  is fixed and positions, with respect to a main scan direction, of the toner images formed by the process units PY to PK are adjusted may also be employed. 
     At a downstream end portion of the first feeding portion  50  with respect to the sheet feeding direction VD, a pre-registration sensor P 1  is provided. The pre-registration sensor P 1  is disposed at a central portion of the feeding passage with respect to the widthwise direction WD. At a downstream end portion of the second feeding portion  55  with respect to the sheet feeding direction VD, an obliquely feeding sensor R 1  and a before-registration sensor Q 1  are provided. Each of the pre-registration sensor P 1 , the obliquely feeding sensor R 1  and the before-registration sensor Q 1  includes a light emitting portion and a light receiving portion. Then, when the sheet S passes through between the light emitting portion and the light receiving portion, light reflected by the sheet S is detected by the light receiving portion, so that passage timing of the sheet S is detected at each of detecting positions of these sensors. 
     [Peripheral Structure of Feeding Roller Pairs] 
     Next, a peripheral structure of the feeding roller pairs  341 ,  342 ,  343  and  344  of the first feeding portion  50  will be described. Each of the feeding roller pairs  341 ,  342 ,  343  and  344  is contacted and separated by a contact-and-separation mechanism. Further, the feeding roller pairs  341 ,  342 ,  343  and  344  and their contact-and-separation mechanisms have the same constitutes, and therefore, in the following, only the feeding roller pair  341  and the contact-and-separation mechanism thereof will be described. 
     As shown in  FIG.  3    and parts (a) and (b) of  FIG.  4   , the feeding roller pair  341  includes a driving roller  13  and a follower roller  14 . The driving roller  13  is supported by a driving shaft  13   a  as shown in  FIG.  3   , and at an end portion of the driving shaft  13   a , a pulley  13   b  is fixed. Around the pulley  13   b , a belt  302  driven by a pre-registration motor Mp is wound, and the pre-registration motor Mp is driven, so that the driving roller  13  is driven. 
     The pre-registration motor Mp as a first driving potion is constituted by a stepping motor, and depending on a detection result of the pre-registration sensor P 1 , driving timing, (drive) stop timing and a driving speed of the pre-registration motor Mp are controlled. By this, driving timing, (drive) stop timing and a rotational speed (feeding speed) of the driving roller  13  are controlled. 
     The follower roller  14  of the feeding roller pair  341  is contacted to and separated from the driving roller  13  by a contact-and-separation mechanism  100  as shown in parts (a) and (b) of  FIG.  4   . The contact-and-separation mechanism  100  as a first contact-and-separation mechanism includes a nip releasing motor  104 , gears  105  and  106 , an eccentric cam  103  and an arm member  101 . The nip releasing motor  104  is constituted by a stepping motor. The gear  105  is not only driven by the nip releasing motor  104  but also engaged with the gear  106 . 
     The gear  106  is rotated integrally with the eccentric cam  103  by the gear  105 . The arm member  101  is supported by a stay member  18 , fixed to a frame of the image forming apparatus  1 , so as to be swingable about a swing shaft  102 . The arm member  101  includes one end portion  101   a  pressed by rotation of the eccentric cam  103  and the other end portion  101   b  supporting a rotation shaft  14   b  of the follower roller  14 . 
     As shown in part (a) of  FIG.  4   , when the eccentric cam  103  is positioned in a first rotation position, the follower roller  14  is press-contacted to the driving roller  13  by an unshown spring. Thus, a nip N 1  is formed by the driving roller  13  and the follower roller  14 . Further, as shown in part (b) of  FIG.  4   , when the eccentric cam  103  is positioned in a second rotation position where the eccentric cam  103  is rotated 180° from the first rotation position, the one end portion  101   a  of the arm member  101  is pressed by a large-diameter portion of the eccentric cam  103 , so that the other end portion  101   b  is swung upward. By this, the follower roller  14  is separated from the driving roller  13 , so that the nip N 1  is released. 
     Thus, the feeding roller pair  341  is capable of being changed in state by the contact-and-separation mechanism  100  between a feedable state (contact state) in which the driving roller  13  and the follower roller  14  which are two rollers constituting the feeding roller pair  341  are capable of feeding the sheet S while nipping the sheet S and a spaced state in which the driving roller  13  and the follower roller  14  are in separation from each other. The nip releasing motor  104  is driven depending on a detection result of the pre-registration sensor P 1 , so that the feeding roller pair  341  is changed between the contact state and the spaced state. 
     For example, in the case where a shifting operation by the obliquely feeding rollers  35 ,  36  and  37  is started, all the feeding roller pairs  341 ,  342 ,  343  and  344  are in the spaced state when the trailing end portion of the sheet S does not pass through the nips. By this, it becomes possible to not only prevent obstruction of the sheet shifting operation by the feeding roller pairs  341 ,  342 ,  343  and  344  but also avoid occurrence of damage of the sheet due to friction or stress on the sheet S. 
     [Peripheral Structure of Obliquely Feeding Rollers] 
     Next, a peripheral structure of the obliquely feeding rollers  35 ,  36  and  37  will be described. As shown in  FIGS.  2  and  5   , the obliquely feeding roller  35  is rotated about a rotation shaft  35   d  and is supported by a rotation shaft  325   a  through a universal joint  325 . The obliquely feeding roller  36  is rotated about a rotation shaft  36   d  and is supported by a rotation shaft  326   a  through a universal joint  326 . The obliquely feeding roller  37  is rotated about a rotation shaft  37   d  and is supported by a rotation shaft  327   a  through a universal joint  327 . 
     The rotation shafts  35   d ,  36   d  and  37   d  extend in directions crossing the sheet feeding direction VD in which the sheet is fed along the feeding passage and the widthwise direction WD perpendicular to the sheet feeding direction VD. Further, the sheet feeding direction of the obliquely feeding rollers  35 ,  36  and  37  is inclined by the angle α relative to the reference surface  31   a  of the reference member  31  by the universal joints  325 ,  326  and  327 , respectively. 
     To the rotation shaft  325   a , a pulley  325   b  is fixed, and to the rotation shaft  326   a , pulleys  326   b  and  326   c  are fixed. Abound the pulleys  326   b  and  326   c , belts  321  and  322  are wound, respectively, and these belts  321  and  322  are driven by an obliquely feeding (roller) driving motor Ms as a second driving portion. To the rotation shaft  327   a , a pulley  327   b  is fixed, and around the pulleys  326   b  and  327   b , the belt  323  is wound. By employing such a constitution, the obliquely feeding driving motor Ms is driven, so that the obliquely feeding rollers  35 ,  36  and  37  are driven. 
     As shown in parts (a) and (b) of  FIG.  6   , in the second feeding portion  55 , an obliquely feeding roller pair is constituted by each of the obliquely feeding rollers  35 ,  36  and  37  and its corresponding follower roller, and a contact-and-separation mechanism for contacting the follower roller to the obliquely feeding roller and for separating the follower roller from the obliquely feeding roller is provided. These follower roller and contact-and-separation mechanism are provided corresponding to the number of the obliquely feeding rollers. For this reason, in the following, a follower roller  331  and a contact-and-separation mechanism  200  which correspond to the obliquely feeding roller  35  will be described, and other follower rollers and their associated contact-and-separation mechanisms will be omitted from description. 
     The contact-and-separation mechanism  200  as a second contact-and-separation mechanism includes an arm member  332 , a link member  333 , a pressing gear  334 , a pressing spring  335 , and an obliquely feeding (roller) pressing motor Mk. The follower roller  331  as a nipping roller is rotatably supported by the arm member  332  and is movable in a direction in which the follower roller  331  approaches the obliquely feeding roller  35  or is separated from the obliquely feeding roller  35  by swing of the arm member  332  about a swinging shaft  332   a . Thus, the follower roller  331  is constituted so s to be changeable in state between a feedable state in which the follower roller is capable of feeding the sheet S in cooperation with the obliquely feeding roller  35  while nipping the sheet S therebetween and a spaced state in which the follower roller  331  is separated from the obliquely feeding roller  35 . 
     The follower roller  331  in this embodiment is rotated along the sheet feeding direction about an axis extending in the widthwise direction WD, but a constitution in which the follower roller  331  is disposed on an axis parallel to its corresponding obliquely feeding roller  35  may also be employed. The arm member  332  is connected to the pressing gear  334  through the pressing spring  335  and the link member  333 . The pressing gear  334  is driven by the obliquely feeding pressing motor Mk which is a driving source. 
     As shown in part (a) of  FIG.  6   , when the pressing gear  334  is rotated in the counterclockwise direction in the figure, the arm member  332  pulled by the pressing spring  335  is swung about the swung shaft  332   a  in the counterclockwise direction. By this, a press-contact state in which the follower roller  331  is press-contacted to the obliquely feeding roller  35  is formed. On the other hand, as shown in part (b) of  FIG.  6   , when the pressing gear  334  is rotated in the clockwise direction in the figure and presses the link member  333 , the link member  332  swings the arm member  322  in the clockwise direction. By this, the follower roller  331  is separated from the obliquely feeding roller  35 , or at least a spaced state in which a contact pressure of the follower roller  331  to the obliquely feeding roller  35  is smaller than a contact pressure in the press-contact state is formed. 
     The obliquely feeding pressing motor Mk is a stepping motor, and by controlling an angle of rotation of the pressing gear  334 , an elongation amount of the pressing spring  335  in the press-contact state is capable of being changed. That is, the contact-and-separation mechanism  200  in this embodiment is capable of carrying out both a change between the press-contact state and the spaced state and a change in pressure in the press-contact state. 
     [Control System] 
     Next, a control system of the sheet aligning portion  90  will be described. As shown in  FIG.  7   , the sheet aligning portion  90  is controlled by a controller  600  as a control portion mounted in the image forming apparatus  1 . The controller  600  includes a CPU  600   a , a ROM  600   b  for storing various programs, and a RAM  600   c  used as a work space for the CPU  600   a.    
     To the controller  600 , an operating portion  412  including an operating panel and physical buttons is connected, and a user is capable of changing various settings of the image forming apparatus  1  and of providing an instruction of a job through the operating portion  412 . 
     Further, to the controller  600 , the registration sensor  8 , the obliquely feeding sensor R 1 , the pre-registration sensor P 1 , the before-registration sensor Q 1 , the pre-registration motor Ms, the obliquely feeding driving motor Ms, the obliquely feeding pressing motor Mk, the nip releasing motor  104  and the like are connected. 
     [Manual Feeding Device] 
     Next, the manual feeding device  40  will be specifically described. As shown in  FIG.  8   , the manual feeding device  40  includes a sheet supporting portion  41  for supporting the sheet S and a feeding portion  429 . The feeding portion  429  includes a feeding roller  42  for feeding the sheet S supported by the sheet supporting portion  41 , and a drawing roller pair  49  provided downstream of the feeding roller  42  with respect to the sheet feeding direction VD and for feeding the sheet S fed by the feeding roller  42 . Incidentally, in this embodiment, two drawing roller pairs  49  are provided, but a single drawing roller pair  49  or three or more drawing roller pairs  49  may also be provided. Further, the drawing roller pair  49  is provided so that the nip cannot be released, and there is no constitution in which the drawing roller pair  49  is contacted and separated. 
     The sheet supporting portion  41  is provided with a pair of first side regulating plates  48  as shown in  FIGS.  9  to  11   . This pair of first side regulating plates  48  is movable in the widthwise direction WD along guiding grooves  48   a  provided in the sheet feeding portion  41  and extending in the widthwise direction WD. 
     Further, a rotation shaft  46  extending in the widthwise direction WD is supported by the sheet supporting portion  41 , and a mounting plate  45  is fixed to the rotation shaft  46 . The rotation shaft  46  is fixed at an arbitrary rotation position by a fixing portion provided at one end with respect to the widthwise direction WD. The mounting plate  45  is provided with a pair of second side regulating plates  43 . The pair of second side regulating plates  43  as a side end regulating portion is movable in the widthwise direction along guiding grooves  43  a provided in the mounting plate  45  and extending in the widthwise direction WD. Further, the pair of second side regulating plates  43  is fixed to the mounting plate  45  by fixing screws  44 , and thus is positioned with respect to the widthwise direction WD. 
     These pair of first side regulating plates  48  and pair of second side regulating plates  43  are positioned in positions depending on a size of the sheet S supported by the sheet supporting portion  41 , so that the position of the sheet S with respect to the widthwise direction WD is regulated (aligned). The first side regulating plates  48  and the second side regulating plates  43  have sufficient lengths in the sheet feeding direction VD, and therefore, oblique movement of the sheet S fed is satisfactorily restricted. Further, the second side regulating plates  43  is capable of adjusting the position of the sheet S with respect to the rotational direction about the rotation shaft  46  as an axis by adjusting a mounting angle of the mounting plate  45 , so that positional deviation of the sheet S in the image forming apparatus  1  can be corrected. 
     In the case where a long sheet (elongated sheet) which is long with respect to the sheet feeding direction VD is fed, even when the sheet reaches the second feeding portion  55 , a trailing end of the sheet is still positioned on the sheet supporting portion  41  in some instances. In this case, in the second feeding portion  55 , even when the sheet is intended to be shifted to the reference member  31  by the obliquely feeding rollers  35 ,  36  and  37 , the first side regulating plates  48  and the second side regulating plates  43  obstruct feeding of the sheet, so that the oblique movement of the sheet is rather promoted. For this reason, in this embodiment, in the case where the elongated sheet is fed, the shift of the sheet by the second feeding portion  55  is not carried out, and in a state in which all the obliquely feeding rollers  35 ,  36  and  37  are in the spaced state, control of feeding the elongated sheet is carried out. 
     Further, even in the case where the obliquely feeding rollers  35 ,  36  and  37  are in the spaced state, when the obliquely feeding rollers  35 ,  36  and  37  on the feeding passage are still rotated, the sheet receives a component of a force by which the sheet is moved toward the reference member  31 , so that the oblique movement occurs. For this reason, in this embodiment, the sheet feeding is carried out while stopping the drive of the obliquely feeding rollers  35 ,  36  and  37 . 
     [Sheet Feeding Control] 
     Next, feeding control of the sheet will be described along flowcharts of  FIGS.  12  and  13   . In  FIGS.  12  and  13   , “Y” represents YES, and “N” represents NO. 
     When an image forming job is started in a state in which pieces of information such as a boss weight, a size, the number of sheets and the like of the sheet are inputted (step S 1 ), the controller  600  discriminates whether or not the sheet is the elongated sheet on the basis of sheet length discrimination control set in advance (step S 2 ). In this embodiment, for example, the sheet is discriminated as the elongated sheet in the case where a sheet length set by the operating portion  412  is longer than a distance, with respect to the sheet feeding direction VD, from the drawing roller pair  49  which is a most downstream roller of the feeding portion  429  to the obliquely feeding roller  35 . Further, for example, the sheet is discriminated as the elongated sheet in the case where the sheet length is longer than a distance, with respect to the sheet feeding direction VD, from a downstream end  43   b  (see  FIG.  1   ) of the second side regulating plate  43  to the obliquely feeding roller  35 . 
     Then, in the case where the sheet is discriminated as the elongated sheet (step S 2 : Y), the controller  600  executes an operation in an elongated sheet feeding mode as a mode including steps S 3  to S 18 . Further, in the case where discrimination that the sheet is not the elongated sheet is made (step S 2 : N), the controller  600  executes an operation in a normal sheet feeding mode including the steps S 19  to S 36 . 
     First, the operation in the elongated sheet feeding mode will be described. As shown in  FIG.  12   , the controller  600  controls the contact-and-separation mechanisms  100  and  200  so that all the feeding roller pairs  341  to  344  and all the obliquely feeding rollers  35  to  37  are put in the spaced states (step S 3 ). Then, the controller  600  starts an image forming operation by the image forming portion  80  (step S 4 ). Then, the controller  600  counts a feeding start delay time on the basis of start timing of the image forming operation (step S 5 ), and then executes a feeding process for feeding process for feeding the sheet S by the feeding portion (step S 6 ). 
     Incidentally, in this embodiment, the sheet S is fed by the feeding roller  42  and the drawing roller pair  49  of the feeding portion  419 . Further, a first feeding motor for driving the feeding roller  42  and a second feeding motor for driving the drawing roller pair  49  are separately provided, and when the feeding of the sheet S is started, the first feeding motor and the second feeding motor are driven. When a leading end of the sheet reaches the drawing roller pair  49 , the drive of the first feeding motor is stopped. During the feeding of the sheet, drive of the pre-registration motor Mp and drive of the obliquely feeding driving motor Ms are stopped, and therefore, the sheet S is fed to a stop position only by the drawing roller pair  49 . 
     Here, since a distance between the pair of first side regulating plates  48  and the pair of second side regulating plates  43  which are provided on the sheet supporting portion  41  is short, the drawing roller pair  49  as a downstream feeding roller pair is capable of feeding the sheet while rectifying the oblique movement of the sheet by the second side regulating plates  43 . On the other hand, the feeding roller pairs  341  to  344  and the obliquely feeding rollers  35  to  37  can constitute a factor causing the oblique movement of the sheet due to, for example, a variation in alignment since the distance between the pair of first side regulating plates  48  and the pair of second side regulating plates  43  is long. However, all the feeding roller pairs  341  to  344  and all the obliquely feeding rollers  35  to  37  are not only put in the spaced states but also drive-stopped, and therefore, the oblique movement of the sheet is not caused to occur. Incidentally, a constitution in which the feeding roller  42  and the drawing roller pair  49  are driven by a single motor may also be employed. 
     Further, the controller  600  discriminates whether or not the pre-registration sensor P 1  is turned on (step S 7 ). A state of the pre-registration sensor P 1  is changed from an OFF state to an ON state by arrival of the sheet S at a detecting position of the pre-registration sensor P 1 . In the case where the pre-registration sensor P 1  is turned on (step S 7 : Y), a stop delay time is counted (step S 8 ), and then the controller  600  executes a stop process for stopping the feeding of the sheet S at a stop position (step S 9 ). The stop of the feeding of the sheet S is carried out by stopping the drive of the drawing roller pair  49 . Further, the leading end of the sheet S positioned in the stop position is in a position downstream of the feeding portion  429  and upstream of the registration roller pair  7  with respect to the sheet feeding direction VD. Specifically, the leading end of the sheet S positioned in the stop position is in a position downstream of the drawing roller pair  49  and upstream of the registration roller pair  7  with respect to the sheet feeding direction VD. 
     Incidentally, in the case where the pre-registration sensor p 1  does not detect the sheet S even when a predetermined time has elapsed from the start of the feeding, a screen showing a sheet jam is displayed on the operating portion  412  (step S 18 ), and execution of the job is ended. 
     After the step S 9 , in a state in which the sheet S is at rest, the controller  600  executes a contact process in which the controller  600  controls the contact-and-separation mechanism  100  so that at least one of the feeding roller pairs  341  to  344  which are a plurality of roller pairs is changed in state from the spaced state to the contact state (step S 10 ). In this embodiment, of the four pairs of feeding roller pairs  341  to  344 , two feeding roller pairs  342  and  344  are changed in state from the spaced state to the contact state. 
     Then, the controller  600  counts a drive start delay time in conformity to progression of the image forming operation (step S 11 ), and then starts the drive of the pre-registration motor Mp (step S 12 ). At this time, it is sufficient that the pre-registration motor Mp for driving the feeding roller pairs  342  and  344  put in the contact state, but the pre-registration motors Mp for driving the feeding roller pairs  341  and  343  still put in the spaced state may also be driven. A feeding process for feeding the sheet S to the registration roller pair  7  is executed by the feeding roller pairs  342  and  344  put in the contact state. The drive start timing of the pre-registration motor Mp is adjusted in conformity to the image forming operation, so that a variation in time until the sheet S reaches the pre-registration sensor P 1  is absorbed. 
     Thereafter, the controller  600  discriminates whether or not the before-registration sensor Q 1  is turned on (step S 13 ). The before-registration sensor Q 1  is changed in state from an OFF state to an ON state by arrival of the sheet S at a detecting position thereof. In the case where discrimination that the before-registration sensor Q 1  is turned on (step S 13 : Y), a delay time for releasing contact (pressing) of each of the feeding roller pairs  342  and  344  is counted (step S 14 ), so that the feeding roller pairs  342  and  344  are put in the spaced states. Incidentally, in the case where the before-registration sensor Q 1  does not detect the sheet S in a predetermined time, the screen showing the sheet jam is displayed at the operating portion (step S 18 ), and then execution of the job is ended. 
     When the sheet S is sent to the secondary transfer portion, by a counter for managing the number K of remaining sheets S to be subjected to image formation, a value of the number K is decremented (step S 16 ). In the case where the number K of remaining sheets S is not 0, i.e., in the case where the sheets to be subjected to image formation remain (step S 17 : N), the above-described operation (steps S 4  to S 17 ) is repeated. In the case where the number K of remaining sheets S is 0 (step S 17 : Y), discrimination that the image forming operation is completed is made, so that execution of the job is ended. 
     Next, an operation in a normal feeding mode will be described. As shown in  FIG.  12   , the controller  600  controls the contact-and-separation mechanisms  100  and  200  so that all the feeding roller pairs  341  to  344  and all the obliquely feeding rollers  35  to  37  are put in the contact states (step S 19 ). Then, the controller  600  starts an image forming operation by the image forming portion  80  (step S 20 ). Then, the controller  600  counts a feeding start delay time on the basis of start timing of the image forming operation (step S 21 ), and then the sheet S is fed by the feeding portion (step S 22 ). 
     In the operation in the normal sheet feeding mode, during the sheet feeding, the pre-registration motor Mp is driven, but the drive of the obliquely feeding driving motor Ms is at rest. For this reason, the sheet S is fed to a stop position by the drawing roller pair  49  of the feeding portion  429  and by the feeding roller pairs  341  to  344 . 
     Then, the controller  600  discriminates whether or not the pre-registration sensor P 1  is turned on (step S 23 ). In the case where the pre-registration sensor P 1  is turned on (step S 23 : Y), a stop delay time is counted (step S 24 ), and then the feeding of the sheet S is stopped (step S 25 ). The stop of the feeding of the sheet S is carried out by stopping the drive of an unshown second feeding motor and the pre-registration motor Mp and thus by stopping the drive of the drawing roller pair  49  and the feeding roller pairs  341  to  344 . 
     Incidentally, in the case where the pre-registration sensor p 1  does not detect the sheet S even when a predetermined time has elapsed from the start of the feeding, a screen showing a sheet jam is displayed on the operating portion  412  (step S 36 ), and execution of the job is ended. 
     After the step S 25 , the controller  600  counts a re-start delay time in conformity to progression of the image forming operation (step S 26 ), and then resumes the drive of the pre-registration motor Mp (step S 27 ). At this time, the obliquely feeding driving motor Ms is also driven, so that the obliquely feeding rollers  35  to  37  are driven. Thereafter, the controller  600  counts a delay time for releasing contact (pressing) of each of the feeding roller pairs  341  to  344  (step S 28 ), and changes the state of the feeding roller pairs  341  to  344  to the spaced state (step S 29 ). 
     By this, an abutment aligning operation for correcting the oblique movement of the sheet S by causing the sheet S to abut against the reference member  31  is started. The abutment aligning operation in the flowchart of  FIG.  13    is performed in a period (steps S 29  to S 32 ) from the release of the pressing of each of the feeding roller pairs  341  to  344  until the obliquely feeding rollers  35  to  37  are put in the spaced state. 
     When the pressing of each of the feeding roller pairs  341  to  344  is released, as shown in  FIG.  2   , the sheet S starts oblique movement relative to the sheet feeding direction VD so as to approach the reference member  31  by a feeding force received from the second feeding portion  55  as shown in  FIG.  2   . That is, the sheet S is obliquely fed along a tangential direction of each of the obliquely feeding rollers  35  to  37  inclined relative to the sheet feeding direction VD and thus is shifted toward the reference surface  31   a  of the reference member  31 . Then, the sheet S further approaches the reference member  31 , so that a side end thereof contacts the reference surface  31   a . By this, the side end of the sheet S is caused to follow the reference surface  31   a  in the case where the side end of the sheet S is inclined with respect to the sheet feeding direction VD, so that the oblique movement of the sheet S is corrected. Incidentally, an actual sheet movement direction does not always coincide with the obliquely feeding roller tangential direction since a slip of the obliquely feeding rollers occur due to the influences such as inertia of the sheet and a feeding resistance exerted on the sheet. 
     Thereafter, the controller  600  discriminates whether or not the before-registration sensor Q 1  is turned on (step S 30 ). In the case where discrimination that the before-registration sensor Q 1  is turned on (step S 30 : Y), a delay time for releasing contact (pressing) of each of the obliquely feeding rollers  35  to  37  is counted (step S 31 ), so that the contact of each of the obliquely feeding rollers  35  to  37  is released and the obliquely feeding rollers  35  to  37  are put in the spaced states. This delay time is set so that the obliquely feeding rollers  35  to  37  are put in the spaced state after the leading end of the sheet S enters the nip of the registration roller pair  7 . Incidentally, in the case where the before-registration sensor Q 1  does not detect the sheet S in a predetermined time, the screen showing the sheet jam is displayed at the operating portion  412  (step S 36 ), and then execution of the job is ended. 
     After the step S 36 , when the sheet S is delivered to the registration roller pair  7 , as shown in  FIG.  2   , the registration roller pair  7  moves in the widthwise direction WD while feeding the sheet S. By this, a center position of the sheet S with respect to the widthwise direction WD is positionally aligned in conformity to a center position of the images formed by the process units PY to PK (step S 33 ). 
     When the sheet S is sent to the secondary transfer portion, by a counter for managing the number K of remaining sheets S to be subjected to image formation, a value of the number K is decremented (step S 34 ). In the case where the number K of remaining sheets S is not 0, i.e., in the case where the sheets to be subjected to image formation remain (step S 35 : N), the above-described operation (steps S 20  to S 35 ) is repeated. In the case where the number K of remaining sheets S is 0 (step S 35 : Y) discrimination that the image forming operation is completed is made, so that execution of the job is ended. 
     As described above, in this embodiment, the above-described operation in the elongated sheet feeding mode can be executed. In the operation in the elongated sheet feeding mode, the sheet S is not fed by the feeding roller pairs  341  to  344  of the first feeding portion  50  and by the obliquely feeding rollers  35  to  37  of the second feeding portion  55 , but is fed to the stop position by the drawing roller pair  49 . These feeding roller pairs  341  to  344  and obliquely feeding rollers  35  to  37  are in the spaced states and the drive-stop states. 
     In other words, at least in a period from the start of the feeding process (step S 6 ) until the feeding process (step S 12 ) is ended, not only the state in which the obliquely feeding roller  35  is separated from the follower roller  331  is maintained but also the drive of the obliquely feeding driving motor Ms is stopped. Further, at least in a period from the start of the feeding process (step S 6 ) until the contact process (step S 10 ) is ended, the drive of the pre-registration motor Mp is stopped. Then, in the feeding process (step S 12 ), the pre-registration motor Mp is driven so that the feeding roller pairs  342  and  344 , which are put in the contact state, of the feeding roller pairs  341  to  344  are driven. 
     For this reason, even when the feeding roller pairs  341  to  344  cannot be disposed in parallel to the registration roller pair  7  due to an alignment deviation and part tolerance, there is no influence of inclination (oblique movement) of the sheet S. Further, a component of a force toward the sheet feeding direction is not imparted to the sheet S by the obliquely feeding rollers  35  to  37 , so that a degree of the oblique movement of the sheet S can be reduced. 
     Then, the sheet S stopped at the stop position is nipped by the feeding roller pairs  342  and  344  which are a part of the feeding roller pairs  341  to  344  and then is fed toward the registration roller pair  7 . At this time, the elongated sheet S is not subjected to abutment alignment at the second feeding portion  55 , but is subjected to alignment with respect to the widthwise direction WD by the pair of first side regulating plates  48  and the pair of second side regulating plates  43 , and therefore, it is possible to reduce the degree of the oblique movement of the sheet S. 
     Further, in the case of the elongated sheet, due to a large sheet size, a feeding resistance when the feeding of the sheet S is resumed (step S 11 ) is particularly large, and therefore, a feeding force necessary to accelerate the sheet S is large, so that improper feeding of the sheet S is liable to occur. Here, for example, when in consideration of the alignment deviation or the like of the feeding roller pairs  341  to  344 , all the feeding roller pairs  341  to  344  are put in the spaced state and the drive-stopped state and the feeding of the sheet S is resumed only by the drawing roller pair  49 , the feeding force is insufficient in some cases. In this embodiment, the feeding roller pairs  342  and  344  are put in the contact state, and the sheet S is fed by the feeding roller pairs  342  and  344 , and therefore, a degree of improper feeding of the sheet S, such as non-feeding or the like of the sheet S due to insufficient feeding force can be reduced. Incidentally, the sheet S may also be fed by not only the feeding roller pairs  342  and  344  put in the contact state but also the drawing roller pair  49 . 
     Other Embodiments 
     In this embodiment, the four feeding roller pairs were provided in the first feeding portion  50 , and the three obliquely feeding rollers were provided in the second feeding portion  55 , but the present invention is not limited thereto. The first feeding portion  50  may only be required to be provided with two or more feeding roller pairs, and the second feeding portion  55  may only be required to be provided with one or more obliquely feeding rollers. 
     Further, in this embodiment, in the contact process shown in the step S 10 , the feeding roller pairs  342  and  344  were changed in state to the contact state, but the present invention is not limited thereto. That is, at least one of the feeding roller pairs  341  to  344  may only be required to be changed in state to the contact state, and for example, all the feeding roller pairs  341  to  344  may also be changed in state to the contact state. Incidentally, depending on an attitude of the sheet S fed, the number of the feeding roller pairs  341  to  344  of which states are changed to the contact state in the above-described contact process may also be changed. The attitude of the sheet S contains, for example, information on the basis weight, the size, a kind (coated paper, non-coated paper or the like), and so on. For example, when a sheet S with a first basis weight is fed, only a first number (for example, one) of roller pairs of the feeding roller pairs  341  to  344  may also be changed in state to the contact state in the contact process. Further, when a sheet S with a second basis weight larger than the first basis weight is fed, a second number (for example, three), more than the first number, of roller pairs of the feeding roller pairs  341  to  344  may also be changed in state to the contact state in the contact process. For example, when a sheet S with a first size is fed, only a first number (for example, one) of roller pairs of the feeding roller pairs  3341  to  344  may also be changed in state to the contact state in the contact process. Further, when a sheet S with a second size larger than the first size is fed, a second number (for example, three), more than the first number, of roller pairs of the feeding roller pairs  341  to  344  may also be changed in state to the contact state in the contact process. 
     Further, in this embodiment, the registration roller pairs  7  capable of being slid (moved) in the widthwise direction WD while nipping the sheet S was provided, but the present invention is not limited thereto. For example, the registration roller pair  7  may also be constituted so that the registration roller pair  7  is not capable of being slid (moved) in the widthwise direction WD although the registration roller pair  7  feeds the sheet S in synchronism with image formation timing. 
     Further, in this embodiment, the contact-and-separation mechanism  200  was constituted so that the follower roller  331  is capable of being contacted to and separated from the obliquely feeding roller  35  was employed, but the present invention is not limited thereto. That is, the contact-and-separation mechanism  200  may only be required to be constituted so that at least either one of the obliquely feeding roller  35  and the follower roller  331  is contacted to and separated from the other roller. Further, the obliquely feeding driving motor Ms driven the obliquely feeding roller  35  but may only be required to drive at least either one of the obliquely feeding roller  35  and the follower roller  331 . 
     Further, in this embodiment, in the operation in the elongated sheet feeding mode, in the period until the contact process (step S 10 ) is ended, the drive of the pre-registration motor Mp was stopped, but the present invention is not limited thereto. For example, in a period from a start of the feeding process (step S 6 ) to a start of the contact process (step S 12 ), the pre-registration motor Mp may also be driven. 
     Further, in either one of the above-described embodiments, the image forming apparatus  1  of the electrophotographic type was described, but the present invention is not limited thereto. For example, the present invention is also applicable to an image forming apparatus of an ink jet type in which an image is formed on a sheet by ejecting an ink liquid through nozzles. 
     The present invention is also capable of being realized in a process in which a program for realizing one or more functions in the above-described embodiments is supplied to a system or an apparatus through a network or a recording medium and then one or more processors in a computer of the system or the apparatus reads and executes the program. Further, the present invention is also capable of being realized by a circuit (for example, ASIC) realizing one or more functions. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2020-054355 filed on Mar. 25, 2020, which is hereby incorporated by reference herein in its entirety.