Patent ID: 6985269

Claim:
An image reading apparatus comprising: an original mounting table; an image sensor for reading an original mounted on said original mounting table; a carriage having said image sensor mounted thereon for movement to scan the original; a driving member, arranged to transmit a moving force to said carriage; a guide member for guiding said carriage in the movement direction thereof, wherein said carriage is biased in a rotating direction centering about an axis perpendicular to said original mounting table by tension of said driving member; and a driving source mounted on said carriage for driving said carriage, a driving pulley mounted on said carriage for transmitting a driving force from said driving source to said driving member, and an idler pulley mounted on said carriage for biasing said driving member, and wherein said carriage is moved by a reaction force received from said driving member, wherein said driving member has a first portion extending parallel to said guide member and in which the spacing between it and said guide member is a first length, a second portion extending parallel to said guide member and in which the spacing between it and said guide member is a second length, and a third portion which is the portion between the first portion and the second portion, and extending non-parallel to said guide member.