| 摘要 |
PROBLEM TO BE SOLVED: To enable a user to freely choose illumination colors to his taste in a color-changing illumination device. SOLUTION: The color-changing device 10 selects illumination colors by choosing a point on a chromaticity diagram with the movement of a joystick 1. Movements of the joystick 1 are converted into voltage signals of X-axis and Y-axis directions, which are A/D converted by a microcomputer 7 on an X-Y coordinate on the chromaticity diagram to determine the illumination colors. Brightness ratios of three colors of LED12R, 12G, 12B for displaying the colors, and duty ratios of lighting on and off are found to match each ratio. The three colors of LED12R, 12G, 12B are lit in accordance with their duty ratios. Since signals to be lit are PMW wave, a structure of control circuit by the microcomputer 7 is simplified, which realizes cost reduction of the color- changing illumination device 10. |
