Method and device for displaying, numerically coding and visualizing colours by trichromatic subtractive synthesis

摘要

According to the device, three moving elements are superposed which carry each a series of density gradings in each of the basic subtractive colours, each density grading being affected with a digit or an identification symbol. It becomes thus possible to recompose a predetermined colour from a definite assembly of digits or symbols as long as the light source is of constant quality. The movable elements may be comprised of concentric cylinders, superposed disks, or endless tapes circulating onto each other on rolls, or boards of transparent material carrying a grading of colours and controlled by slides under masks.