| 摘要 |
PURPOSE:To enable to obtain a fine tone reproduction without changing the density of dots by a method wherein the optical concentration of the dots is changed by increasing and decreasing the thermal energy. CONSTITUTION:A thermal head is provided which is fed intermittently and transversely with respect to a heat-sensitive papaer 1. After the line feed of the thermal head is conducted, the heat-sensitive paper 1 is fed longitudinally by a predetermined span at a time, and the geometrical density of the dots 2 is determined by the combination of the longitudinal feed span of the paper 1 and the transverse feed span of the thermal head. The heat capacity of the thermal head is extremely small. The image to be represented on the heat-sensitive paper 1 is converted into electrical signals, and current is supplied at the position of each dot 2, whereby thermal energy is applied to the heat-sensitive paper 1 to cause a color change, embodying the dot 2. Since the duration of the current supply for the thermal head at the position of each dot 2 is set in gradation, the dots 2 are provided with plural kinkds of colors and the assembly thereof represents an image full of tone including halftone. |
