Sheet transporting apparatus having gear assembly for mounting rotating shaft, and scanner and image processing apparatus using the same

Abstract

A sheet transporting apparatus includes a housing, a rotating shaft, a roller and a gear assembly. The housing includes a first supporting member and a second supporting member. The rotating shaft is rotatably mounted in the housing. The rotating shaft has a first end portion mounted in the first supporting member, and a second end portion mounted in the second supporting member. The roller is attached to the rotating shaft and rotated by the roller to transport a document sheet. The gear assembly, coupled to the second end portion, transmits power to the rotating shaft. The gear assembly includes a gear member and a coupling member, rotatable with the gear member, for securing the second end portion to the second supporting member.

1 . A sheet transporting apparatus, comprising:
 a housing comprising a first supporting member and a second supporting member;   a rotating shaft, which is rotatably mounted in the housing and has a first end portion mounted in the first supporting member, and a second end portion mounted in the second supporting member;   a roller, mounted on the rotating shaft and rotated by the rotating shaft, for transporting a document sheet; and   a gear assembly, coupled to the second end portion, for transmitting power to the rotating shaft, the gear assembly comprising:
 a gear member; and 
 a coupling member, rotatable with the gear member, for securing the second end portion to the second supporting member. 
   
     
     
         2 . The apparatus according to  claim 1 , wherein the coupling member comprises a sleeve formed with a plurality of elastic hooks for securing the second end portion to the second supporting member, wherein the sleeve is wedged into an opening of the second supporting member and fastened to the second supporting member by the elastic hooks, such that the gear assembly is immovable in an axial direction of the rotating shaft. 
     
     
         3 . The apparatus according to  claim 1 , wherein the gear member comprises a hollow body for accommodating the second end portion of the rotating shaft. 
     
     
         4 . The apparatus according to  claim 3 , wherein the hollow body has a D-shaped cavity, the second end portion has a D-shaped cross section matching with the D-shaped cavity to fix the gear assembly to the rotating shaft, so that the rotating shaft is driven by the gear assembly. 
     
     
         5 . The apparatus according to  claim 1 , wherein the gear member comprises gear teeth for meshing with gear teeth of a driving gear and for transmitting power to the rotating shaft. 
     
     
         6 . The apparatus according to  claim 1 , further comprising a scanning module, disposed in the housing, for scanning an image of the document sheet transported by the roller. 
     
     
         7 . The apparatus according to  claim 1 , wherein the first end portion of the rotating shaft comprises a small-diameter section and a large-diameter section coaxially disposed with the small-diameter section, wherein a diameter of the small-diameter section is smaller than that of the large-diameter section, and the small-diameter section is seated within an opening of the first supporting member. 
     
     
         8 . The apparatus according to  claim 1 , wherein a surface of the gear assembly facing a wall of the second supporting member is formed with a plurality of projections, and the plurality of projections are in direct contact with the second supporting member. 
     
     
         9 . The apparatus according to  claim 1 , wherein the first supporting member has a first opening, and the second supporting member has a second opening. 
     
     
         10 . The apparatus according to  claim 9 , wherein the first end portion is seated within the first opening, and the second end portion passes through the second opening. 
     
     
         11 . The apparatus according to  claim 10 , wherein an outer periphery of the coupling member of the gear assembly rests against an inner peripheral wall of the second opening. 
     
     
         12 . A scanner comprising the sheet transporting apparatus according to  claim 1 . 
     
     
         13 . An image processing apparatus comprising the sheet transporting apparatus according to  claim 1 .