| 摘要 |
PURPOSE:To prevent degradation of print quality for a large number of copies and to reduce noise for a small number of copies, by controlling printing speed and exciting current necessary for projecting a print pin correspondingly to the number of copies. CONSTITUTION:A printer comprises a mechanism for adjusting a gap between the tip of a print head 15 and a sheet 12 corresponding to the number of sheets 12 to be set on a platen 11. A detection plate 19 rotates in the direction of an arrow X upon advance of a shaft 14 and rotates in the direction of an arrow Y upon retreat of the shaft 14. Sensors 20a, 20b are arranged on a moving path of the detection plate 19. A control circuit detects the number of sheets 12 through combination of ON/OFF of the sensors 20a, 20b and controls printing speed and exciting current necessary for projecting a print pin correspondingly to the number of sheets 12. Since printing is made with impact force optimal for the number of sheets 12, printing quality for multi-sheets does not degrade and in minimal-copy printing can be reduced. |
