| 摘要 |
PURPOSE:To obtain a printer capable of maintaning uniform printing quality and also of obtaining uniform printing density by using a system in which test letters permitting reference density to grasp are printed. CONSTITUTION:The value of exciting current (b), or printing pressure, can be freely set up within a given range. CPU is designed to make test printing when test start signal is input. By printing pressure parameters, the wave height value H is made constant and pulse width T is set up at equal intervals from zero to one corresponding to printing pressure sufficiently exceeding usual printing density. When test printing is ended, test letters A whose density is orderly increased from the adjacent letter region of reference letter I to the right side are continuously printed on a test paper 21. Letters positioned on the side where the density is increased from readable starting letter 52 by the preset number (5 in Fig.) of letters are regarded as reference printing pressure letters 5, and therefore, no difference is produced in judged results due to different regulators or mechanical factors of printers. |
