Wire-driving system, and image reader using such wire-driving system

An image reader comprising:

• an elongated image scanner unit that is movable along a guide path defined by a first side and a second side opposite to each other;
• a drive drum member rotatably provided on a first end of said elongated image scanner unit so as to be rotated around a rotational axis which is perpendicular to a movement direction of said elongated image scanner unit;
• a drive source provided in said elongated image scanner unit and operationally connected to said drive drum member so as to be rotationally driven in either a first rotational direction or a second rotational direction;
• a first wire cable having a first end and a second end, and partially wound around said drive drum member such that a first cable section and a second cable section are extended from said drive drum member;
• a second wire cable having a first end and a second end, and partially wound around said drive drum member such that a first cable section and a second cable section are extended from said drive drum member;
• the first end of said first wire cable and the second end of said second wire cable being securely attached to two fixed points beside terminal ends of the first side of said guide path such that the first cable section of said first wire cable and the second cable section of said second wire cable are tensionally extended along the first side of said guide path;
• and
• a wire-cable deflector provided on a second end of said elongated image scanner unit such that the second cable section of said first wire cable and the first cable section of said second wire cable are threaded through said wire-cable deflector so as to laterally traverse said guide path, whereby the second end of said first wire cable and the first end of said second wire cable are securely attached to two fixed points beside ends of the second side of said guide path such that the second cable section of said first wire cable and the first cable section of said second wire cable are tensionally extended along the second side of said guide path,
• wherein both the first cable sections of said first and second wire cables and both the second cable sections of said first and second wire cables are respectively wound around and unwound from said drive drum member during the rotation of said drive drum member in the first rotational direction by said drive source, and both the first cable sections of said first and second wire cables and both the second cable sections or said first and second wire cables are respectively unwound from and wound around said drive drum member during the rotation of said drive drum member in the second rotational direction by said drive source, resulting in the movement of said elongated image scanner unit along said guide path.