| 摘要 |
PURPOSE:To provide a dot type printing device that is of simple construction, inexpensive and excellent in movement accuracy by providing the device with intermittent driving of the carriage by means of a combination of a DC motor capable of forwad and reverse rotation and a spring clutch and controlling letter printing by means of slit plate rotation that is synchronized with the intermittent driving. CONSTITUTION:A DC motor 8 is connected to a clutch mechanism 12 through gears 9 and 11 and a clutch shaft 10. Further, ratchet wheels 14 and 15 are provided that are for feeding positive and negative directions through coil springs 16 and 17 are provided on both sides of a clutch gear 13 that is fitted on the shaft 10 rotatably. A carriage 3 driven by a gear 18 that engages the clutch gear 13, and a slit plate 21 for detection is fixed on the shaft 19 of a gear 20 that also engages the clutch gear 13. A group 22 of slits for printing signal that corresponds to the number of teeth of the ratchet wheels 14 and 15 are formed on the slit plate 20. The number of slits of each group of slits is made the same as the number of dots that form a letter. A detection mechanism 25 is provided on both sides of the slit plate 21. |
