Automatic sheet feeder

Abstract

An automatic sheet feeder including a sheet input tray, a sheet output tray, a first passageway and a second passageway, a temporary storage region, and a sheet-feeding mechanism. The sheet-feeding mechanism transports a first sheet from the sheet input tray to the temporary storage region at a first time through the first passageway, successively transports the first sheet from the temporary storage region to the second passageway, from the second passageway to the first passageway, and from the first passageway to the temporary storage region at a second time, and then outputs the first sheet from the temporary storage region to the sheet output tray. The sheet is transported across an image processing region twice in either the simplex or duplex feeding mode.

1 . An automatic sheet feeder, comprising: 
 a sheet input tray for storing a plurality of sheets including a first sheet and a second sheet, each of the first sheet and second sheet having a front side and a back side;    a sheet output tray for storing the first sheet and the second sheet after the first sheet and the second sheet are fed;    a first passageway and a second passageway, through which the first sheet and the second sheet may be successively fed, the first passageway communicating with the sheet input tray, a first end of the second passageway selectively communicating with the first passageway, and a second end of the second passageway communicating with the first passageway;    a temporary storage region, which selectively communicates with the first passageway and the second passageway and is located above the sheet output tray; and    a sheet-feeding mechanism for transporting the first sheet and the second sheet from the sheet input tray to the sheet output tray, wherein    the sheet-feeding mechanism transports the first sheet from the sheet input tray to the temporary storage region at a first time through the first passageway, successively transports the first sheet from the temporary storage region to the second passageway, from the second passageway to the first passageway, and from the first passageway to the temporary storage region at a second time, and then outputs the first sheet from the temporary storage region to the sheet output tray.    
   
   
       2 . The automatic sheet feeder according to  claim 1 , wherein the sheet-feeding mechanism comprises: 
 a guiding rod for switchably guiding the first sheet from the first passageway to the temporary storage region, and guiding the first sheet from the temporary storage region to the second passageway.    
   
   
       3 . The automatic sheet feeder according to  claim 1 , wherein the sheet-feeding mechanism comprises: 
 a sheet-input roller for feeding the first sheet from the sheet input tray to the first passageway; and    a sheet-output roller set for transporting the first sheet from the first passageway to the temporary storage region while clamping the first sheet, or releasing the first sheet to let the first sheet fall down to the sheet output tray.    
   
   
       4 . The automatic sheet feeder according to  claim 3 , wherein the sheet-feeding mechanism further comprises: 
 a first roller set located in the first passageway to assist in transporting the first sheet from the sheet input tray to the temporary storage region, and assisting in transporting the first sheet from the second passageway to the temporary storage region.    
   
   
       5 . The automatic sheet feeder according to  claim 3 , wherein the sheet-feeding mechanism further comprises: 
 a guiding rod for switchably guiding the first sheet from the first passageway to the temporary storage region, and guiding the first sheet from the temporary storage region to the second passageway.    
   
   
       6 . The automatic sheet feeder according to  claim 1 , wherein the first passageway is formed with an image processing region.  
   
   
       7 . The automatic sheet feeder according to  claim 6 , further comprising a scanning module, which is disposed at the image processing region, for scanning the first sheet passing through the image processing region.  
   
   
       8 . The automatic sheet feeder according to  claim 6 , wherein the first sheet is transported to the temporary storage region twice when the front side and the back side of the first sheet are processed in the image processing region, and the first sheet is transported to the temporary storage region twice when only the front side or the back side of the first sheet are processed in the image processing region.  
   
   
       9 . The automatic sheet feeder according to  claim 1 , wherein the first sheet falls from the temporary storage region to the sheet output tray.