| 摘要 |
PURPOSE: To provide a light accumulative display device which makes a display visible in a dark place at all times with low electric power. CONSTITUTION: The surface of the dial of a watch frame is provided with an index 3 (hand 4) coated with a light accumulative coating material 3a (4a). An optical sensor 5 is disposed in a position where the light energy released by the index 3, etc., is detectable. A light emitting source (miniature bulb) 6 is disposed in a position where light energy is suppliable to the index 3, etc. A CPU 10 sends an on signal to light the light to the light emitting source 6 when the detection signal received from the optical sensor 5 falls down to the prescribed value or below. The light emitting source 6 lights for a specified time to illuminate the index 3, etc., and supplies the light energy to the index, etc. The light accumulative coating material 3a (4a) releases the light energy to make the index 3, etc., visible when the light emitting source 6 is put out. The light emitting source 6 begins to be lighted again via the optical sensor 5 and the CPU 10 when the brightness falls down to the prescribed value or below. The operation repeats henceforth. |
