Automatic document feeder

Abstract

An automatic document feeder includes an upper cover, a sheet separation member and a crank. The sheet separation member includes a separation roller, a separation pad and a first elastic element. When the upper cover is opened, the upper cover is separated from the crank, and a first extension part of the crank is uplifted to push a second extension part of the separation pad, so that the separation pad is separated from the separation roller.

1 . An automatic document feeder, comprising:
 a casing;   an upper cover;   a sheet separation member comprising a separation roller, a separation pad and a first elastic element, wherein in response to an elastic force provided by said first elastic element, said separation roller and separation pad are pressed by each other; and   a crank disposed under said upper cover, wherein a first end of said crank is connected to said casing through a second elastic element, and a first extension part is formed on a second end of said crank, wherein when said upper cover is pressed down, said crank is pushed by said upper cover to be rotated in a first direction, wherein when said upper cover is opened, said upper cover is separated from said crank, said crank is driven by said second elastic element to be rotated in a second direction, and said first extension part of said crank is uplifted to push said second extension part of said separation pad, so that said separation pad is permitted to resist said elastic force of said first elastic element and separated from said separation roller.   
     
     
         2 . The automatic document feeder according to  claim 1  wherein said crank has a slant surface, and a pressing block is formed on a lower surface of said upper cover, wherein when said upper cover is pressed down, said pressing block is contacted with said slant surface, so that said crank is rotated in said first direction. 
     
     
         3 . The automatic document feeder according to  claim 1  wherein a notch is formed in said first extension part of said crank, and said second extension part of said separation pad has a tab, wherein said tab is inserted into said notch. 
     
     
         4 . The automatic document feeder according to  claim 1  wherein said crank is L-shaped. 
     
     
         5 . The automatic document feeder according to  claim 1  wherein said first elastic element is a compression spring. 
     
     
         6 . The automatic document feeder according to  claim 1  wherein said second elastic element is a tension spring.