Paper feed roller and image forming apparatus with the paper feed roller

Abstract

The invention provides a paper feed roller capable of reducing abnormal noise caused by a knurled shape while maintaining characteristics thereof, including maintaining friction coefficient and coping with paper powder. The paper feed roller comprises a roller body formed of elastic material in a cylindrical shape and is characterized in that the roller body has protruding lines and recessed grooves inclinedly extending relative to an axis of the roller body so that convex and concave portions having predetermined widths are alternatively formed in a circumferential direction of a peripheral surface, and the protruding lines have one-end side protruding line portions extending from a central part in an axial direction of the roller body toward one end thereof and other-end side protruding line portions extending from the central part in the axial direction toward the other end, and they are inclined relative to the axis in opposite directions.

What is claimed is: 
     
         1 . A paper feed roller comprising a roller body formed of elastic material in a cylindrical shape, wherein
 the roller body includes a plurality of protruding lines and recessed grooves inclinedly extending relative to an axis of the roller body so that convex portions with predetermined width and concave portions with predetermined width are alternatively formed in a circumferential direction of a peripheral surface of the roller body, and   the plurality of protruding lines include one-end side protruding line portions extending from a central part of the roller body in a direction of an axis of the roller body toward one end of the roller body and other-end side protruding line portions extending from the central part in the direction of the axis of the roller body toward an other end of the roller body, and the one-end side protruding line portions and the other-end side protruding line portions are inclined relative to the axis of the roller body in opposite directions each other.   
     
     
         2 . The paper feed roller according to  claim 1 , wherein the one-end side protruding line portions and the other-end side protruding line portions extend at substantially equal angles relative to the axis of the roller body and the angles of extending directions of the one-end side protruding line portions and the other-end side protruding line portions relative to the axis of the roller body are no less than 5° and no more than 15°. 
     
     
         3 . The paper feed roller according to  claim 1 , wherein the one-end side protruding line portions and the other-end side protruding line portions are provided so that ends of the one-end side protruding line portions at the central part of the roller body and ends of the other-end side protruding line portions at the central part of the roller body are offset in the circumferential direction of the roller body. 
     
     
         4 . Image forming apparatus comprising the paper feeding roller according to  claim 1 .