Document ejecting mechanism and document feeder using the same

Abstract

A document ejecting mechanism includes an output roller, a roller shaft, an idle roller, an idle shaft and an adjusting device. The roller shaft inserts through the output roller, which rotates the idle roller. The idle shaft inserts through the idle roller. The adjusting device adjusts a distance between the output roller and the idle roller. A document feeder using the document ejecting mechanism is also disclosed.

1 . A document ejecting mechanism, comprising:
 an output roller;   a roller shaft inserting through the output roller;   an idle roller rotated by the output roller;   an idle shaft inserting through the idle roller; and   an adjusting device, for adjusting a distance between the output roller and the idle roller.   
     
     
         2 . The document ejecting mechanism according to  claim 1 , wherein the adjusting device comprises:
 a driving unit, for driving one end of at least one of the roller shaft and the idle shaft.   
     
     
         3 . The document ejecting mechanism according to  claim 2 , wherein the adjusting device further comprises:
 a leverage mechanism, wherein one end of the leverage mechanism contacts with the one end of one of the roller shaft and the idle shaft,   wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move one of the roller shaft and the idle shaft.   
     
     
         4 . The document ejecting mechanism according to  claim 3 , wherein the driving unit comprises a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move one of the roller shaft and the idle shaft. 
     
     
         5 . The document ejecting mechanism according to  claim 2 , wherein the adjusting device moves the one end of one of the roller shaft and the idle shaft from a first position to a second position, and the document ejecting mechanism further comprises:
 a torsional spring, wherein one end of the torsional spring connected to one of the roller shaft and the idle shaft, and the torsional spring is for providing a restoring force to one of the roller shaft and the idle shaft to move the one end of one of the roller shaft and the idle shaft from the second position to the first position.   
     
     
         6 . The document ejecting mechanism according to  claim 1 , further comprising:
 a rod connected to one of the roller shaft and the idle shaft, wherein the adjusting device comprises a driving unit for moving one end of the rod to shift one of the roller shaft and the idle shaft.   
     
     
         7 . The document ejecting mechanism according to  claim 6 , wherein the adjusting device comprises:
 a leverage mechanism, wherein one end of the leverage mechanism contacts with the one end of the rod,   wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move the rod.   
     
     
         8 . The document ejecting mechanism according to  claim 7 , wherein the driving unit comprises a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move the rod. 
     
     
         9 . The document ejecting mechanism according to  claim 6 , further comprising:
 a sleeve assembly for connecting the rod to one of the roller shaft and the idle shaft,   wherein one of the roller shaft and the idle shaft inserts through a first sleeve, and the rod inserts through a second sleeve.   
     
     
         10 . The document ejecting mechanism according to  claim 6 , wherein the adjusting device moves the one end of the rod from a first position to a second position, and the document ejecting mechanism further comprises:
 a torsional spring, having one end connected to the rod, for providing a restoring force to the rod to move the one end of the rod from the second position to the first position.   
     
     
         11 . A document feeder, comprising:
 a sheet input tray for storing a document;   a group of passageways;   an image processing region disposed in the group of passageways; and   a document transporting device, for transporting the document from the sheet input tray into the group of passageways with each of a front side and a back side of the document being transported across the image processing region once, and then transporting the document to a sheet output tray of the document feeder, the document transporting device comprising a document ejecting mechanism, which comprises:
 an output roller; 
 a roller shaft inserting through the output roller; 
 an idle roller rotated by the output roller; 
 an idle shaft inserting through the idle roller; and 
 an adjusting device, for adjusting a distance between the output roller and the idle roller. 
   
     
     
         12 . The document feeder according to  claim 11 , wherein the document transporting device further comprises:
 a plurality of document transporting rollers and a plurality of document transporting idle rollers, wherein one of the document transporting rollers and the output roller is driven by one reversible power source.   
     
     
         13 . The document feeder according to  claim 12 , further comprising:
 a control circuit, connected to the reversible power source and the adjusting device; and   a document detector, connected to the control circuit and disposed in the group of passageways, for detecting a position of the document and thus outputting a position signal to the control circuit, wherein the control circuit controls the adjusting device to adjust the distance between the output roller and the idle roller and controls the reversible power source to drive one of the document transporting rollers and the output roller to rotate clockwise or counterclockwise according to the position signal.   
     
     
         14 . The document feeder according to  claim 11 , wherein the adjusting device comprises:
 a driving unit for driving one end of at least one of the roller shaft and the idle shaft.   
     
     
         15 . The document feeder according to  claim 14 , wherein the adjusting device further comprises:
 a leverage mechanism having one end contacting with the one end of one of the roller shaft and the idle shaft,   wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move one of the roller shaft and the idle shaft.   
     
     
         16 . The document feeder according to  claim 15 , wherein the driving unit comprises a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move one of the roller shaft and the idle shaft. 
     
     
         17 . The document feeder according to  claim 14 , wherein the adjusting device moves the one end of one of the roller shaft and the idle shaft from a first position to a second position, and the document ejecting mechanism further comprises:
 a torsional spring, wherein one end of the torsional spring connected to one of the roller shaft and the idle shaft, and the torsional spring is for providing a restoring force to one of the roller shaft and the idle shaft to move the one end of one of the roller shaft and the idle shaft from the second position to the first position.   
     
     
         18 . The document feeder according to  claim 11 , wherein the document ejecting mechanism further comprises:
 a rod connected to one of the roller shaft and the idle shaft, wherein the adjusting device comprises a driving unit for moving one end of the rod to shift one of the roller shaft and the idle shaft.   
     
     
         19 . The document feeder according to  claim 18 , wherein the adjusting device comprises:
 a leverage mechanism, wherein one end of the leverage mechanism contacts with the one end of the rod,   wherein the driving unit drives the other end of the leverage mechanism to drive the one end of the leverage mechanism to move the rod.   
     
     
         20 . The document feeder according to  claim 19 , wherein the driving unit has a solenoid and a driving part, wherein the solenoid drives the driving part, the driving part moves the other end of the leverage mechanism and the one end of the leverage mechanism is driven to move the rod. 
     
     
         21 . The document feeder according to  claim 18 , further comprising:
 a sleeve assembly for connecting the rod to one of the roller shaft and the idle shaft,   wherein one of the roller shaft and the idle shaft inserts through a first sleeve, and the rod inserts through a second sleeve.   
     
     
         22 . The document feeder according to  claim 18 , wherein the adjusting device moves the one end of the rod from a first position to a second position, and the document ejecting mechanism further comprises:
 a torsional spring, wherein one end of the torsional spring connected to the rod, and the torsional spring is for providing a restoring force to the rod to move the one end of the rod from the second position to the first position.