| 摘要 |
An apparatus and method for controlling the velocity of a moving member like, for example, a print head carrier. The apparatus includes motor means which drives the carrier along the platen of a printer. The motor is driven by alternately energizing it during an "on" period and de-energizing it during an "off" period. A velocity detector detects the actual velocity of the carrier and determines whether an overspeed or an underspeed condition exists relative to a desired velocity. A counter capable of counting pulses relative to the on and off periods is utilized to receive the signals from the velocity detector and to effectively shorten or lengthen the "on" period, respectively, whenever an overspeed or underspeed condition exists. |
