| 摘要 |
The control system (3) controls a first chronological sequence of ejected ink-drops from a first set of feeds (B1-B5) to print a first set of lines (MB1-MB5) extending longitudinally in the direction of displacement following a series of ladder steps. The system then controls a second chronological sequence of ejected ink-drops from a partic. feed (B'128) to print a second series of lines (MB'128) to one side of the first series of lines. The print head (2) has a photo-detection unit (22) arranged behind the ink feeds (R1,R2) following the direction of displacement. The detector (22) is mounted to move perpendicular to the displacement to detect in sequence the two print lines and provides a signal (22S) representing a detection sequence of the lines. The control system (3) is connected to the detector (22) to identify a feed from the first set which is in alignment with the particular feed (B'128), when the signal (22S) is received, and then stops operation of some of the feeds (B1-B3;B1,B2, B'B128) of the two set of feeds during printing of the franking design. |
