Sheet feeding device

Abstract

Imaging target media stacked in a tray are bent in a width direction orthogonal to a transmission direction so that rigidity of the imaging target media in the transmission direction increases than the rigidity before bending. Consequently, even though a separation imaging-target medium is bound together with a transportation imaging-target medium using a binding member, the separation imaging-target medium is transmitted to an imaging unit along with the transportation imaging-target medium by transporting rollers without bending in the transmission direction. A superimposed-transmission of the imaging target media is detected by sensors and rotation of the transmitting roller is stopped. Due to this, the superimposed-transmission of the imaging target media is stopped just before the imaging unit.

1 . A sheet feeding device comprising:
 a tray in which sheet-type imaging target media are stacked;   a transmitting roller that rotates and transmits, upon touching a single imaging target medium that is to be transported among the stacked imaging target media, the touched transportation imaging-target medium to an imaging unit;   a separating unit that touches, among the stacked imaging target media, a separation imaging-target medium that is not to be transported, separates the separation imaging-target medium by moving the separation imaging-target medium in a direction opposite to the transportation imaging-target medium that is transmitted to the imaging unit by the transmitting roller, and prevents transmission of the separation imaging-target medium to the imaging unit;   a rotatably driving unit that rotatably drives the transmitting roller;   a transporting roller that rotates and transports, upon touching the transportation imaging-target medium transmitted by the transmitting roller, the touched transportation imaging-target medium to an imaging position of the imaging target medium formed by the imaging unit;   a detecting sensor that is set between the transmitting roller and the transporting roller and that detects whether the imaging target media transmitted by the transmitting roller are only the transportation imaging-target media; and   a controlling unit that stops, upon determining that the detected imaging target media include the imaging target media other than the transportation imaging-target media, rotation of at least the transmitting roller via the rotatably driving unit,   wherein the tray includes a bending unit that bends the stacked imaging target media from a rear to a front end of a transmission direction, in a direction that intersects the transmission direction of the imaging target media by the transmitting roller and reduces a degree of bending of the imaging target media from the rear end to the front end of the transmission direction.   
   
   
       2 . The sheet feeding device according to  claim 1 , wherein
 the bending unit includes a foundation member facing the stacked imaging target media and a pair of bending members mounted on the foundation member on both edges of a width direction that is orthogonal to the transmission direction, and   the bending members project in a stacking direction of the imaging target media and an amount of projection reduces along the transmission direction.   
   
   
       3 . The sheet feeding device according to  claim 2 , wherein
 the bending members are supported on both edges of the width direction of the foundation member such that the bending members can be raised above the foundation member, and   the bending members project, upon raising, from lateral surfaces of the foundation member in a stacking direction of the imaging target media and the amount of projection reduces along the transmission direction.   
   
   
       4 . The sheet feeding device according to  claim 2 , wherein at least one of the two bending members is supported such that the bending member can slide over the foundation member along the width direction. 
   
   
       5 . The sheet feeding device according to  claim 2 , wherein the bending members include mutually opposing guiding units that regulate a movement of the imaging target media transmitted by the transmitting roller, in the width direction. 
   
   
       6 . The sheet feeding device according to  claim 1 , further comprising:
 a pressing member arranged facing the tray and that includes a bending and pressing member that presses the imaging target media stacked in the tray towards the tray and bends the imaging target media according to a shape of the bending unit, and a supporting unit that supports the bending and pressing unit at the front end.   
   
   
       7 . The sheet feeding device according to  claim 6 , wherein, depending on a reaction force due to a pressing force exerted by the pressing and bending unit on the imaging target media, the pressing and bending unit of the pressing member can oscillate in a direction away from the tray with a proximal portion of the supporting unit as a center. 
   
   
       8 . The sheet feeding device according to  claim 6 , wherein the pressing and bending unit includes a sliding roller supported by the supporting unit allowing free rotation, and the pressing and bending unit slides with respect to the pressed imaging target media along with a movement of the pressed imaging target media in the transmission direction.