Paper feeding device and an electronic apparatus having the same

Abstract

A paper feeding device and an electronic apparatus having the same include a pickup roller moving upwardly and downwardly to selectively contact a document stacked on a document tray. A restrainer moves in directions for blocking a leading end of a document stacked on the document tray from the feeding roller when the pickup roller is lifted, and for unblocking the leading end of document from the feeding roller when the pickup roller is lowered. Accordingly, unintended contact between the document and the feeding roller is prevented when stacking the document, thereby preventing damage of the document during paper feeding.

1 . A paper feeding device for an electronic apparatus, comprising: 
 a pickup roller moving upwardly and downwardly to selectively contact a document stacked on a document tray and to feed the contacted document; and    a restrainer moving between a first position that blocks a leading end of the document stacked on the document tray from the feeding roller when the pickup roller is lifted and a second position that unblocks the leading end of the document from the feeding roller when the pickup roller is lowered.    
   
   
       2 . The paper feeding device of  claim 1 , wherein the restrainer includes 
 a stopper restraining the leading end of the document from entering a main body of the electronic apparatus while the restrainer is lowered; and    a guide part connected to one side of the stopper and facing an upper side of the document being fed to the feeding roller while the restrainer is lifted.    
   
   
       3 . The paper feeding device of  claim 2 , wherein 
 a lifting and lowering driver lowers the restrainer when the pickup roller is lifted and lifts the restrainer when the pickup roller is lowered.    
   
   
       4 . The paper feeding device of  claim 3 , wherein 
 the pickup roller is connected to a driving source disposed in the electronic apparatus through a predetermined gear train, and    the lifting and lowering driver includes a pinion mounted at the gear train, and a rack gear part formed at one side of the restrainer along an ascending and descending direction of the restrainer that engages the pinion.    
   
   
       5 . The paper feeding device of  claim 4 , wherein 
 the pinion is coaxially arranged with one idler gear selected from a plurality of idler gears mounted to the gear train, and    the lifting and lowering driver includes a clutch disposed between the pinion and rotary shaft of the selected idler gear for selective power transmission.    
   
   
       6 . The paper feeding device of  claim 5 , wherein 
 the selected idler gear connected with the pinion is rotated in the same direction with the pickup roller.    
   
   
       7 . The paper feeding device of  claim 6 , wherein 
 the feeding roller is disposed between the driving source and the pickup roller to feed the document fed by the pickup roller into the main body of the electronic apparatus, and    the selected idler gear is one of the plurality of idler gears connecting the feeding roller and the pickup roller to each other.    
   
   
       8 . The paper feeding device of  claim 7 , wherein 
 a frame rotatably supports the idler gears and the pickup roller, and pivots with respect to the feeding roller when the feeding roller is rotated; and    the frame has a guide groove that slidably receives a side of the restrainer.    
   
   
       9 . The paper feeding device of  claim 8 , wherein 
 the clutch includes a spring clutch that rotates the pinion when the selected idler gear is rotated in a direction for lifting the restrainer and releases the connection between the selected idler gear and the pinion when the selected idler gear is rotated in a direction for lowering the restrainer, so that the restrainer descends by its own weight, and    the restrainer has a contacting portion that contacts the frame at a predetermined position when being lifted by rotation of the pinion.    
   
   
       10 . The paper feeding device of  claim 7 , wherein 
 a detecting sensor detects the document as fed to a predetermined position by the feeding roller, and    the feeding roller is driven in the opposite direction to a direction of feeding the document into the main body when the detecting sensor detects the document, thereby lifting the pickup roller and lowering the restrainer.    
   
   
       11 . The paper feeding device of  claim 2 , wherein 
 a friction member is mounted to face the feeding roller to substantially prevent multi-sheet feeding by creating friction with the fed document; and    the guide part is slanted with respect to the stopper to form an angle for guiding the document between the friction member and the feeding roller.    
   
   
       12 . An electronic apparatus, comprising: 
 a pickup roller picking up a document stacked on a document tray;    a feeding roller feeding the document picked by the pickup roller to an image sensor; and    a restrainer moving between a first position for blocking a leading end of the document from the feeding roller when the pickup roller is lifted, and a second position for unblocking the leading end of the document from the feeding roller when the pickup roller is lowered.    
   
   
       13 . The electronic apparatus of  claim 12 , wherein the restrainer includes 
 a stopper restrains the leading end of the document from advancing to the feeding roller while the restrainer is lowered; and    a guide part connected to one side of the stopper and facing an upper side of the document being fed to the feeding roller while the restrainer is lifted.    
   
   
       14 . The electronic apparatus of  claim 13 , wherein 
 the guide part is slanted with respect to the stopper to face an upper side of the document being fed by the pickup roller to the feeding roller when the restrainer is lifted.    
   
   
       15 . The electronic apparatus of  claim 13 , wherein 
 a lifting and lowering driver lowers the restrainer when the pickup roller is lifted and lifts the restrainer when the pickup roller is lowered.    
   
   
       16 . The electronic apparatus of  claim 15 , wherein 
 the pickup roller is connected to the feeding roller through a plurality of idler gears to be rotated in association with rotation of the feeding roller, and    the lifting and lowering driver includes a pinion connected with one idler gear selected from the plurality of idler gears, and a rack gear part formed at one side of the restrainer along an ascending and descending direction of the restrainer and that engages the pinion.    
   
   
       17 . The electronic apparatus of  claim 16 , wherein 
 the lifting and lowering driver includes a clutch disposed between the pinion and a rotary shaft of the selected idler gear for selective power transmission, and    the clutch rotates the pinion when the selected idler gear is rotated in a direction that separates the restrainer from the document.    
   
   
       18 . The electronic apparatus of  claim 16 , wherein 
 a frame rotatably supports the idler gears and the pickup roller and pivots so that the pickup roller is selectively contacted with the document according to rotation of the feeding roller; and    the selected idler gear connected to the pinion is pivoted in a direction for lifting the restrainer when the pickup roller is lowered.    
   
   
       19 . The electronic apparatus of  claim 18 , wherein 
 the frame rotatably supports the feeding roller and movably supports the restrainer; and    the pickup roller, the idler gears, the restrainer, the lifting and lowering driver, the feeding roller, and the frame are formed as a single module that is mounted to a main body of the electronic apparatus.    
   
   
       20 . The electronic apparatus of  claim 16 , wherein 
 the pinion is coaxially connected with the selected idler gear, which is rotated in the same direction as the pickup roller; and    the clutch is a spring clutch including a spring connecting the pinion with a rotary shafts of the selected idler gear.    
   
   
       21 . A paper feeding device for an electronic apparatus, comprising: 
 a feeding roller rotatable in a first direction for feeding a document picked up and fed from a document tray by a pickup roller into a main body of the electronic apparatus; and    a restrainer movably disposed between the pickup roller and the feeding roller to open a pathway between the pickup roller and the feeding roller only when the feeding roller is rotated in the first direction.    
   
   
       22 . The paper feeding device of  claim 21 , wherein 
 a lifting and lowering driver lifts and lowers the restrainer in association with the feeding roller.    
   
   
       23 . The paper feeding device of  claim 22 , wherein the restrainer includes 
 a stopper blocking the document pathway between the pickup roller and the feeding roller when the restrainer is lowered; and    a guide part slantingly connected to one side of the stopper and facing an upper side of the document being fed to the feeding roller when the restrainer is lifted.    
   
   
       24 . The paper feeding device of  claim 23 , wherein the lifting and lowering driver includes 
 a pinion connected with one idler gear selected from a plurality of idler gears that power-transmittably connect the feeding roller and the pickup roller; and    a rack gear part formed at one side of the restrainer along an ascending and descending direction of the restrainer and that engages the pinion.    
   
   
       25 . The paper feeding device of  claim 24 , wherein 
 the lifting and lowering driver includes a clutch connecting the pinion with the selected idler gear for selective power transmission.    
   
   
       26 . The paper feeding device of  claim 24 , wherein 
 the pinion and the selected idler gear are coaxially arranged with each other, and    the clutch is a spring clutch connecting a rotary shaft of the pinion and a rotary shaft of the selected idler gear.    
   
   
       27 . The paper feeding device of  claim 23 , wherein 
 the feeding roller is rotated in a second direction opposite to the first direction after completing document feeding by rotating in the first direction, and    the pickup roller is lowered to contact the document when the feeding roller is rotated in the first direction and is lifted in to be separated from the document when the feeding roller is rotated in the second direction.    
   
   
       28 . The paper feeding device of  claim 27 , wherein 
 the restrainer is lifted as the feeding roller is rotated in the first direction to open the document pathway between the feeding roller and the pickup roller, and is lowered as the feeding roller is rotated in the second direction to block the document pathway between the feeding roller and the pickup roller.    
   
   
       29 . The paper feeding device of  claim 23 , wherein 
 the restrainer is lifted as the feeding roller is rotated in the first direction to open the document pathway between the feeding roller and the pickup roller, and is lowered as the feeding roller is not driven to block the document pathway between the feeding roller and the pickup roller.    
   
   
       30 . The paper feeding device of  claim 29 , wherein 
 the restrainer is lowered by its own weight after the document feeding is completed.