| 摘要 |
PROBLEM TO BE SOLVED: To make display easily visible by adopting the constitution to change the light emitting colors of LED units of a green display in accordance with the sensor signals detected by an illuminance sensor, thereby changing the green light emitting LED units to red or orange of higher luminance when the ambient illuminance is high. SOLUTION: The LED display device 1 contains an electrical control means in a case 2 and has an LED display panel 3 and an illuminance sensor 5. The display device is installed at, for example, a platform and displays train names, departure time, etc. The first line L1, second line L2 of such LED display panel 3 are so set that, for example, the characters A to F of the first line L1 are displayed green and the characters G to L of the second line L2 are displayed red. When the strong direct rays of the sun fall onto the LED display panel 3, the illuminance sensor 5 detects a light quantity and the control means changes the colors of the LED display panel 3. The green display of A to F of the first line L1 is changed to, for example, orange and the luminance thereof is made equal to or higher than the luminance of G to L of the red display of the second line L2. |
