Patent ID: 7139106

Claim:
An image scanner comprising: an elongate body having an image reading surface for facing an original document; a substrate provided in the body in parallel to the image reading surface; a line sensor extending in the body longitudinally thereof and mounted on the substrate in facing the relationship to the image reading surface for reading the document as the body moves along the document; a roller shaft rotatably supported in the body to extend longitudinally of the body; at least one roller supported on the roller shaft for rotating therewith while rolling on the document; a rotary encoder for detecting the rotation of said at least one roller for determining a scanning distance of the body, the rotary encoder including a rotary disk supported 15 on a disc shaft; and a drive transmission for connecting said at least one roller to the rotary encoder; wherein the rotary disc is oriented parallel to the substrate and the image reading surface; and wherein the drive transmission comprises a first pulley mounted on the roller shaft, a second pulley mounted on the disc shaft, a belt wound around the first pulley and the second pulley. and a pair of intermediate pulleys for bending the belt.