Media stocker and paper feeder

Abstract

A media stocker includes a feeder plate configured to maintain a plurality of recording media in a stacked state thereon, a vertically elevating device configured to cantilever-support the feeder plate, and a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate. And the media stocker includes a roller attached to the free end side of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device.

What is claimed is: 
     
         1 . A media stocker comprising:
 a feeder plate configured to maintain a plurality of recording media in a stacked state thereon;   a vertically elevating device configured to cantilever-support the feeder plate;   a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate; and   a roller attached to the free end of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device.   
     
     
         2 . The stocker of  claim 1 , wherein the roller is placed into contact with the guide member when at least a predetermined maximum number of recording media are loaded on the feeder plate. 
     
     
         3 . The stocker of  claim 1 , wherein a lower end of the guide member is pivotable around its horizontal shaft, and an upper end of the guide member is detachable therefrom. 
     
     
         4 . The stocker of  claim 1 , further comprising a separating device disposed opposite the free end side of the feeder plate, the separating device being configured to separate only the uppermost recording media. 
     
     
         5 . The stocker of  claim 4 , further comprising a sensor configured to detect whether the recording media reaches a position just ahead of the separating device. 
     
     
         6 . The stocker of  claim 1 , wherein the roller is separated from the guide member when the recording media are not loaded on feeder plate, and the roller is placed into contact with the guide member when the recording media are loaded on feeder plate so as to cause the feeder plate to incline downward. 
     
     
         7 . The stocker of  claim 1 , wherein the feeder plate is held by one side. 
     
     
         8 . A paper feeder comprising:
 a feeder plate configured to maintain a plurality of recording media in a stacked state thereon;   a vertically elevating device configured to cantilever-support the feeder plate;   a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate;   a roller attached to the free end side of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device; and   a pickup roller configured to pick up and convey the uppermost of recording media stacked on the feeder plate to a paper feed opening of an image forming apparatus.   
     
     
         9 . The feeder of  claim 8 , further comprising a separating device disposed opposite the free end side of the feeder plate, the separating device being configured to separate only the uppermost from the recording media picked-up and to convey the uppermost of recording media to the pickup roller. 
     
     
         10 . The feeder of  claim 9 , further comprising a sensor disposed between the pickup roller and the separating device, the sensor being configured to detect whether the recording media reaches a position just ahead of the separating device. 
     
     
         11 . A mass media stocker for stacking and holding a plurality of recording media on a cantilever-supported feeder plate and for feeding the uppermost of the recording media to a paper feed opening of an image forming apparatus, the feeder plate capable of elevating the recording media, the stocker media stocker comprising:
 a guide member disposed vertically to face the free end of the feeder plate so as to guide the recording media stacked on the feeder plate,   wherein when the free end of the feeder plate is inclined downward due to the weight of the plurality of recording media stacked and held thereon, the guide member supports the position where a trajectory according to the downwardly inclining movement of the free end is convex outwardly from a vertical plane including the free end at its initial position.   
     
     
         12 . The stocker of  claim 11 , further comprising a separating device configured to separate only the uppermost recording media. 
     
     
         13 . The stocker of  claim 12 , further comprising a sensor configured to detect whether the recording media arrived the position just before the separating device. 
     
     
         14 . A feeder comprising:
 a media stocker configured to stack and hold a plurality of recording media on a cantilever-supported feeder plate and further being configured to feed the uppermost of the recording media to a paper feed opening defined by an image forming apparatus, the feeder plate being capable of elevating the recording media, the media stocker comprising
 a guide member disposed vertically to face the free end of the feeder plate so as to guide the recording media stacked on the feeder plate, 
 wherein when the free end of the feeder plate is inclined downward due to the weight of the plurality of recording media stacked and held thereon, the guide member supports the position where a trajectory according to the downwardly inclining movement of the free end is convex outwardly from a vertical plane including the free end at its initial position; and 
   a pickup roller configured to pick up to convey the uppermost of recording media stacked on the feeder plate to the paper feed opening of defined by the image forming apparatus.   
     
     
         15 . The feeder of  claim 14 , further comprising a separating device disposed opposite the free end side of the feeder plate, the separating device being configured to separate only the uppermost from the recording media picked-up and to convey the uppermost of recording media to the pickup roller. 
     
     
         16 . The feeder of  claim 15 , further comprising a sensor disposed between the pickup roller and the separating device, the sensor being configured to detect whether the recording media reaches a position just ahead of the separating device. 
     
     
         17 . A method for controlling the configuration of recording media, the method comprising:
 stacking and holding a plurality of recording media on a cantilever-supported feeder plate, the feeder plate capable of elevating the recording media; and   supporting the position of the feeder plate so as to prevent a trajectory according to the downwardly inclining movement of the free end of the feeder plate from being convex outwardly from a vertical plane including the free end at its initial position, when the free end is inclined downwardly due to the weight of the plurality of recording media stacked and held on the feeder plate.   
     
     
         18 . The method of  claim 17 , further comprising picking up the recording media to convey the recording media stacked on the feeder plate. 
     
     
         19 . The method  claim 17 , further comprising separating only the uppermost recording media picked-up and conveyed to the pickup roller. 
     
     
         20 . The method of  claim 19 , further comprising sensing to detect whether the recording media reaches a position just before separating.