| 摘要 |
<p>PURPOSE:To enable execution of rapid vertical enlarging printing by switching the period of a horizontal synchronizing signal according to enlarging magnification. CONSTITUTION:For example, when a CPU 1 inputs an indication according to which enlarging printing is to be effected with double vertical enlarging magnification, ordinary drawing is effected on a frame buffer 2 by a timing control part 4 without enlarging data. Thereafter, the CPU l outputs printing starting and double vertical enlarging magnification commands to a mechanical control part 6. When the commands are received, the mechanical control part 6 generates a horizontal synchronous signal, having the number of pulses being a half the number of longitudinal dots of a paper, at a period two times as long as that of ordinary printing by means of a horizontal synchronous signal generating part 3. A timing control part 4 reads data, equivalent to data for one line of a paper, from the frame buffer 2 by DMA transfer, performs serial conversion of the data by means of a parallel/serial converting part 5, and feeds the data as video data to a printing head to effect printing. In this case, by performing one full exposure until the pulse of a next horizontal synchronous signal is inputted, the same data as that of a preceding dot line is printed.</p> |
