| 摘要 |
<p>PURPOSE:To achieve the miniaturization and enhancement of capacity of a printer by suppressing the width thereof in the moving direction of a carriage to the min. degree, by changing over the phase of a stepping motor after a predetermined time is elapsed from the point of time when a motor timing signal is generated. CONSTITUTION:Since the number of continuing pulses are made constant in a constant speed region, it is confirmed whether MTS arrives fast or a signal at every alpha arrives fast in the final region thereof. In this case, the value set to a timer 53 is a fixed value i.e. alpha. When the signal at every alpha arrives faster than MTS, a carriage is in a state just before stopping. At this time, closed loop control is performed so as to perform speed reduction while a stepping motor is certainly subjected to stepping feed without stepping out. This control is achieved by performing phase change-over a DELTATn time after an MTS signal is detected. That is, by changing over the phase of the stepping motor to the next phase, the next MTS signal is issued necessarily and, therefore, a carriage can be forcibly moved. Herein, the phase is changed over so as to be shifted from MTS by DELTAT1, DELTAT2, DELTAT3... because torque is too strong when the phase is changed over by MTS.</p> |
