| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration of display quality caused by temperature distribution of a liquid crystal panel. SOLUTION: On starting up the device, the temperature distribution A3 of a liquid crystal panel P gets equal to the composition of the temperature distribution A1 due to fluorescent lamps 2a, 2b and the temperature distribution A2 due to heat confined within a case C. Also in the case a thermister S detects the fact that the temperature distribution width (the difference between the highest and the lowest temperature) of the liquid crystal panel P becomes larger than the specified value, a lighting circuit 3 functions to reduce the luminance of the upper side fluorescent lamp 2a and elevate the luminance of the lower side fluorescent lamp 2b. Thereby the temperature distribution due to the fluorescent lamps 2a, 2b gets as is shown with a mark A4, the composition of the temperature distributions gets as is shown with a mark A5 and the temperature differenceΔT1 between the highest temperature A5max and the lowest temperature A5min of the panel temperature is reduced. Consequently deterioration of display quality is prevented. |
