| 摘要 |
<p>PROBLEM TO BE SOLVED: To make securable the luminance of a display character at the time of starting operation even after a long-time operation so as to make the display character easily viewable, by automatically correcting the degradation with year in the luminance of the display character on the basis of an individual lighting time of each dot LED. SOLUTION: When floor display data are inputted into a communication circuit 17, an MPU 11 displays characters on a floor-indicator/direction light 14, while a timer 15 counts reference time at any time. The MPU 11 calculates the difference between a counted value of the timer 15 at the time of switching of display contents in the floor-indicator/direction light 14 and one at the time of switching of next display contents, adds the calculated difference to data in a storage area of a memory 30 corresponding to each dot LED, and repeats these operations hereafter. By referring to a lighting time of each the dot LED stored in the memory 30, the MPU 11 can calculate a present luminance of each the dot LED on the basis of a luminance change caused by secular degradation of the dot LED. On the basis of the calculated present luminance, the MPU 11 lengthens a pulse width of each segment signal by a width corresponding to the degradation in the luminance of the display character so as to make the luminance of the display character brighter.</p> |
