Sheet feeding apparatus

Abstract

A sheet feeding apparatus includes a sheet feeding channel, a sheet feeding structure, a sheet stopping structure, plural sensing arms, an optical sensor and a controller. By the sheet feeding structure, a paper sheet is fed into the sheet feeding channel. The sheet stopping structure is used for stopping the paper sheet from being moved forwardly. During the process of feeding the paper sheet, the plural sensing arms are pushed by the paper sheet to be rotated. According to the rotating statuses of the sensing arms, the optical sensor issues different signals to the controller. According to these signals, the controller will control the operations of the sheet stopping structure and the sheet feeding structure, thereby correcting the skew condition.

1 . A sheet feeding apparatus, comprising:
 a sheet feeding channel;   a sheet feeding structure for allowing at least one paper sheet within said sheet feeding channel to be fed forwardly in a first direction;   a sheet stopping structure for stopping said at least one paper sheet from being moved in said first direction;   plural sensing arms disposed between said sheet feeding structure and said sheet stopping structure and arranged along a second direction, which is perpendicular to said first direction, wherein each of said sensing arms comprises a contacting terminal, a sheltering terminal and a rotary part, wherein said rotary part is arranged between said contacting terminal and said sheltering terminal, wherein when said at least one paper sheet is contacted with said contacting terminal, said sensing arm is rotated by using a center axel of said rotary part as a pivot;   at least one optical sensor comprising a light transmitter and a light receiver, wherein when a light beam from said light transmitter is received by said light receiver, said optical sensor issues a first signal,
 wherein when said light beam from said light transmitter is sheltered by said sheltering terminal of any sensing arm, said light beam fails to be received by said light receiver, and said optical sensor issues a second signal; and 
 wherein when said light beam from said light transmitter is again received by said light receiver said optical sensor issues a third signal; 
   a controller connected with said optical sensor and said sheet stopping structure, wherein if said first signal, said second signal and said third signal are sequentially received by said controller, said sheet stopping structure is controlled by the controller to allow said at least one paper sheet to be continuously moved forwardly in said first direction.   
     
     
         2 . The sheet feeding apparatus according to  claim 1  further comprising a feed sensing module for detecting whether said at least one paper is placed in said sheet feeding channel, wherein said controller is connected with said sheet feeding structure and said feed sensing module, wherein when said feed sensing module detects that said at least one paper is placed in said sheet feeding channel, said feed sensing module issues a third signal to said controller, wherein in response to said third signal, said sheet feeding structure is enabled by said controller. 
     
     
         3 . The sheet feeding apparatus according to  claim 2  wherein said feed sensing module comprises:
 a second optical sensor comprising a second light transmitter for emitting a second light beam and a second light receiver for receiving said second light beam; and 
 a feed sensing structure comprising a sheet feeding part, a sensing part and a rotary shaft, wherein said sheet feeding part and said sensing part are fixedly connected with said rotary shaft, and said sensing part is arranged between said second light transmitter and said light receiver, wherein when said at least one paper sheet is not contacted with said sheet feeding part, said second light beam from said second light transmitter is sheltered by said sensing part, so that said second light beam from said second light transmitter fails to be received by said second light receiver, wherein when said at least one paper sheet is contacted with said sheet feeding part to push said sheet feeding part, said sheet feeding part is rotated by using said rotary shaft as a pivot and said sensing part is rotated with said sheet feeding part, so that said second light beam from said second light transmitter is received by said second light receiver. 
 
     
     
         4 . The sheet feeding apparatus according to  claim 2  wherein said feed sensing module comprises:
 a second optical sensor comprising a second light transmitter for emitting a second light beam and a second light receiver for receiving said second light beam; and 
 a feed sensing structure comprising a sheet feeding part, a sensing part and a rotary shaft, wherein said sheet feeding part and said sensing part are fixedly connected with said rotary shaft, wherein when said at least one paper sheet is not contacted with said sheet feeding part, said second light beam from said second light transmitter is received by said second light receiver, wherein when said at least one paper sheet is contacted with said sheet feeding part to push said sheet feeding part, said sheet feeding part is rotated by using said rotary shaft as a pivot and said sensing part is rotated with said sheet feeding part, so that said second light beam from said second light transmitter is sheltered by said sensing part and fails to be received by said second light transmitter. 
 
     
     
         5 . The sheet feeding apparatus according to  claim 1  wherein said sheet feeding structure comprises a feed roller and a feed roller shaft, wherein said feed roller is fixedly connected with said feed roller shaft, and said feed roller is rotated as said feed roller shaft is rotated. 
     
     
         6 . The sheet feeding apparatus according to  claim 5  wherein said sheet stopping structure comprises plural sheet stopping arms and a sheet stopping shaft, wherein said sheet stopping shaft is parallel with said feed roller shaft, and said plural sheet stopping arms are disposed on said sheet stopping shaft and arranged along said second direction. 
     
     
         7 . The sheet feeding apparatus according to  claim 1  further comprising a fixing shaft, wherein both ends of said fixing shaft are respectively fixed on two sides of said sheet feeding apparatus, and said rotary part of each sensing arm is pivotally coupled with said fixing shaft. 
     
     
         8 . The sheet feeding apparatus according to  claim 7  wherein said rotary part of each sensing arm is a cylindrical post.