PRINTER

PURPOSE:To make possible the detection of paper width and an initial carriage position using a single sensor by arranging a member to be detected for detection of an initial carriage position near one end of a platen and at the same time, mounting a detection sensor for detection of paper width and said member on the carriage. CONSTITUTION:If a printer is switched ON and paper is supplied using a paper transport mechanism in such a manner that the paper is wound around a platen 3, the carriage 6 is moved by the activation of a paper detection switch, and the width of the paper is detected by a detection sensor 20 and CPU during the movement of the carriage 6. After this, the carriage 6 is again moved, and the detection sensor 20 is positioned against a plate to be detected 21. Then light emitted by a light emitter on the detection sensor 20 is reflected by the plate 21. This results in the more rapid reception of light by a light receiver. After this, the location of the carriage 6 at an initial position is detected by CPU, and the drive of the carriage 6 is immediately stopped. Subsequently, it is possible to place the carriage 6 at an initial position.