Patent ID: 7643184

Claim:
A scanner comprising: a base; an elongate image sensor carriage extending in a first direction; a cover; and a driving device including an elongate guiding unit mounted in said base, disposed under said image sensor carriage, and extending along a second direction transverse to the first direction, said guiding unit having at least one top rail surface, and first and second side rail surfaces transverse to said top rail surface, a roller unit mounted rotatably on a bottom side of said image sensor carriage, said roller unit including at least one first roller rotatable about a first axis parallel to the first direction and disposed to roll along said top rail surface, and at least one second roller rotatable about a second axis transverse to the first and second directions and disposed to roll along said first side rail surface, a spring-loaded retaining unit mounted on said bottom side of said image sensor carriage, and disposed to contact rotatablely said second side rail surface, and a driving unit for driving said image sensor carriage to move in the second direction in the base.