Abstract: A position detector has first and second timing disks, each having at least one light-transmissive portion.The second timing disk is rotated at a predetermined speed ratio with respect to the first timing disk. A timing sensor is disposed in close proximity to the outer circumference of the first and second timing disks to provide a timing signal when both the light-transmissive portions of the first and second timing disks rotating at predetermined speeds simultaneously pass by the position of the timing sensor.

Abstract: A platen assembly for a print station apparatus, which comprises first and second indepently movable platen units for holding recording medium so as to compensate for thickness of the medium, a third platen unit interposed between the first and second platen units and independently movable from the first and second platen units, the third platen unit having a minimum length necessary for holding the centerfold of the medium, and first and second springs secured to the first and second platen units and biasing the third platen unit toward a guide of the print station apparatus.