| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to represent a satisfactory gradation even in a low gradation part which cannot be conventionally represented due to the characteristics of a printing head, in an ink jet printer capable of printing an image of a half tone. SOLUTION: When the range of optical density of an output to input data from 0 to 255 is set to 1.5 and a dither method is applied using 16 stage intervals of output density, one of these stage intervals equals about 0.1 as a density modulation consists of 16 stages. Therefore, a control means (CPU) calculates an approximate straight line C by using a signal density dither method which adopts only a density of 0D value = 0.3 for a low gradation part of 0D value = 0.3 or lower based on the performance of a mixing nozzle and makes correction as shown by the graph. Thus it is possible to represent the gradation of the low gradation part. |
