| 摘要 |
1426757 Selective printers XEROX CORP 23 Feb 1973 [25 Feb 1972] 9075/73 Heading B6F [Also in Division G1] A platen 11 in a printer is rotatable either manually by knobs 12, 13 or by a stepping motor 24 through a gear train 26, the stepping motor having a natural detent every fourth step when rotated manually. The stepping motor and gear means are such that four steps of the motor is equivalent to half a line space of the printer. The stepping motor may comprise a rotor consisting of six equiangularly spaced rotatable poles of alternate polarity and two fixed poles positioned 90 degrees apart and of reversible polarity (Fig. 3, not shown) having 12 steps per revolution, or preferably has 48 steps per revolution. |
