Patent ID: 8430399

Claim:
A paper tray for supporting a paper, said paper tray comprising: a first plate comprising a receiving space and a guiding groove, wherein said guiding groove is located within said receiving space; and an extension mechanism accommodated within said receiving space, and comprising: a second plate comprising a sliding groove, wherein said sliding groove is formed in a bottom surface of said second plate; a paper stopper pivotally coupled to said second plate and rotatable relative to said second plate; and an elastic element disposed in said guiding groove of said first plate, and comprising a helical part, a first elastic arm, and a second elastic arm, wherein said helical part is contacted with a surface of said guiding groove and movable relative to said guiding groove, said first elastic arm is connected with said paper stopper, and said second elastic arm is accommodated within said sliding groove of said second plate, wherein when said second plate is moved to a first position in a direction opposite to said first plate and said paper stopper is rotated in a first direction, said elastic element is pushed by an end of said paper stopper, so that said elastic element generates an elastic potential energy, wherein when said paper stopper is rotated in a second direction, said elastic potential energy drives movement of said elastic element in a direction facing said first plate, so that said second plate is moved to a second position and accommodated within said receiving space.