| 摘要 |
<p>PURPOSE:To improve printing quality of a variable density surface image by making a gradation charateristic due to areal gradation of a dither method or the like excellent by a method wherein applicable energy of each LED element is varied according to presence or not of a printing data of a dot existing around an optional dot to be printed in an LED head. CONSTITUTION:When a printing data P1 is of a High level, output of an AND circuit 60 comes to be of a High level. Consequently, an output signal X comes to be of a Low level, and an LED is made to emit light. For a data selective circuit 57, only when a decoder output Y1 is of a Low level, a printing data P2 is of a Low level, and a printing data P1 is of a High level, the output signal X comes to be of a Low level, and an LED is made to emit light during t1. A driving pulse by t0 is a pulse for executing essential printing, and a t1-t8 pulse is a correcting pulse to be applied by a data. The less a number of circumferential ON dots is, energy to be applied is made the larger. The more the number of circumferential On dots is, the energy to be applied is made the less.</p> |
