| 摘要 |
<p>PURPOSE:To alleviate a process conducted in a CPU and contrive a higher printing speed, by storing data for each timing for simultaneous driving of heat generating elements ordinarily used, for at least three runs including at least two past runs and the present run, mixing the data with an energization section signal, and controlling an energization time for the heat generating elements. CONSTITUTION:A head-controlling circuit operates as a kind of peripherals for a CPU, and is allocated to a specified address on a memory map. Numerals 31, 32 and 33 denote latch circuit groups for holding a one-dot-column amount of data on the present run, the last run, and the run before the last, respectively. An energization pulse generating circuit 34 generates a signal for demodulating an energization signal modulated by a period signal which is sent from the CPU, as an energization section signal. The output signal from the circuit 34 is mixed with driving data stored in a storage circuit by gate circuits 37 (GO), which output driving signals for heat generating elements. The circuit 37 adds a preheating pulse in a gate circuit 39 according to the driving histories of gate circuits 38 and 40 corresponding respectively to the past driving data and the present driving data. Therefore, the CPU is required only to discriminate the type of a printing mode, set an optimum energization section and convert it into a period signal.</p> |
