| 摘要 |
PURPOSE:To provide a concrete composition for preventing the occurrence of a wrong operation in paper width detection caused by the separation of a surface treatment layer of a guide through abrasion between it and paper and the change of a rate of the light reflection in a paper width detecting device for use in an ink jet recording apparatus, optically scanning paper moving on the guide, and detecting the paper width by the change of a quantity of light reflection. CONSTITUTION:Each provided on a carriage 6 moving in the normal direction with respect to the running direction of paper 2 traveling along the surface of a guide 1 is an ink jet recording head 4 for jetting ink toward the paper 2 on the guide 1 and paper width detecting means 5 for detecting the width of the paper 2 on the guide 1 by the change of a quantity of light reflection irradiated toward the surface of the guide 1, and a recessed groove 1a is formed on the guide surface to be irradiated with irradiation beams from the paper width detecting means 5. |
