| 摘要 |
<p>PURPOSE:To improve the transfer property of a head black bit while keeping the reproducibility of a fine pattern by a method wherein the energy applied to the heat generator element of a thermal head is controlled so that heating quantity is lowered when the spatial frequency in the periphery of a pixel to be recorded is high and increased when low. CONSTITUTION:The corresponding coefficient value of a coefficient ROM 5 having a spatial frequency-coefficient table optimumly set, for example, so that heating energy becomes low at high spatial frequency and contrarily becomes high as the spatial frequency becomes low is selected on the basis of the spatial frequency value detected from a matrix detecting the spatial frequency in the periphery of a pixel to be recorded and imparted to a multiplier 6. At this time, a memory address generating part 2 reads the image data of the head bit of the first line from a memory 1 to apply the same to a reference energy generating part 3. The reference energy generating part 3 generates the drive output corresponding to said image data and the drive output multiplied by the coefficient value outputted from the coefficient ROM 5 by the multiplier 6 is applied to the heat generator element of a thermal head TPH at the dot position concerned.</p> |
