Patent ID: 7146911

Claim:
An image recorder comprising: a transport element for transporting a rectangular printing plate in a first direction; a positioning element for moving said printing plate in a second direction perpendicular to said first direction, thereby positioning said printing plate in said second direction; an image recording element for directing a light beam onto said printing plate positioned in said second direction by said positioning element, thereby recording an image on said printing plate; a first input device for entering a reference position used for punching positioning holes for printing press in said printing plate; a second input device for entering an approximate width of said printing plate; a measuring element for obtaining a measured width of said printing plate; a first transport member having fixed thereto a first abutment member to be in contact with one edge of said printing plate; a second transport member having a second abutment member to be in contact with the other edge of said printing plate, said second abutment member being slightly movable in said second direction; and a motor for moving said first transport member and said second transport member individually in said second direction, wherein (i) when said first input device enters said one edge of said printing plate as a reference position, a first reference position on the side of said one edge and a second reference position on the side of said other edge are calculated on the basis of said approximate width, (ii) when said first input device enters a central position of said printing plate in said second direction as a reference position, said first reference position on the side of said one edge and said second reference position on the side of said other edge are calculated on the basis of said measured width, (iii) when said first input device enters said other edge as a reference position, said first reference position on the side of said one edge is calculated on the basis of said approximate width and said measured width while said second reference position on the side of said other edge is calculated on the basis of said approximate width, and said motor moves said first transport member such that said first abutment member reaches said first reference position and moves said second transport member such that said second abutment member reaches said second reference position.