| 摘要 |
PURPOSE:To permit the detection of paralleism of a platen from print density by a method in which a tapered face is formed at the end portion of the platen and test printing is conducted. CONSTITUTION:Tapered portions 10b and 10b' are provided on both sides of the the usual using region of a platen 10a in such a way as to alter the distance between a printing head 21 and the platen 10a. Also, indicators 14 and 14' are each provided in parallel with the platen 10a in the spaces of the tapered portions 10b and 10b'. When conforming the parallelism, a printing paper 11 of a width covering the tapered portions 10b and 10b' of the platen 10a is set, a printing head 21 is actuated, and specified letters are printed on the tapered portions 10b and 10b' on both ends, whereupon printing density is gradually reduced toward both ends of the tapered portions 10b and 10b'. Then, value corresponding to the density are read out by the graduations of the indicators 14 and 14' to obtain the values of the parallelism with the movement of the platen and the printing head by difference in values between the right and left-handed indicator graduations. |
