| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize correction of the difference among the spectral characteristics of every one of three primary colors through a simple controlling without lowering writing speed of every color in a full color dealing type by a method wherein controlling means for changing the maximum opening time of optical shutter chips for every one of the three primary colors are provided. SOLUTION: Spectral characteristics of every one of three primary colors of a photographic paper to an optical writing head are judged by measuring the densities of respective images, which are actually drawn through exposure by actuating a printer. When the measured results show that the spectral sensitivities of the three primary colors are more favorable in the order of B>G>R, the maximum opening times of the optical shutter chips at the exposures of respective colors are controlled so as to be in inverse proportion to their spectral sensitivities. Through the controlling as mentioned above, the difference among the spectral characteristics of the respective colors are corrected, resulting in allowing to reproduce a variable contrast image without uneven density and with high quality. In addition, the certain driving voltages of a lamp and optical shutter chips can be kept. Further, the lowering of a writing speed can be avoided without changing-over lamps.</p> |
