JPS641545A - Gradation recording method - Google Patents

Abstract

PURPOSE:To perform gradation recording not inferior to that using many kinds of multi-concentration inks, by making light ink larger in the size of a dot matrix than dark ink and performing gradation recording by the combination of the dark and light inks. CONSTITUTION:The image data are inputted from an input part to generate X-and Y-addresses indicated by X-and Y-counters for dark and light inks and the dot pattern corresponding to the values of the image data and stored in a buffer memory 27 for light ink and a buffer memory 28 for dark inks. The dot pattern is determined by a method wherein patches due to all of the combinations of the light and dark inks are outputted to measure the optical reflection densities thereof and the obtained data are arranged in the order of O- and D-values to be allowed to correspond so as to bring the image data to linear relation and, further, only the light inks are used in a low density region and, after all of the light inks are driven in, the introduction of the dark inks is started and, in medium and high density regions, the dark inks are increased while the light inks are decreased and only the dark inks are used in the max. density region. Therefore, by using two kinds of the dark and light inks, the same gradation recording as the case using three kinds of dark, medium and light inks can be performed.