AIR COOLING METHOD FOR PROJECTION TYPE LIQUID CRYSTAL DISPLAY DEVICE

摘要

PURPOSE:To reduce the deterioration of a polarizing plate caused by the temp. rise of the polarizing plate and to accurately project a video. CONSTITUTION:As for the projection type liquid crystal display device provided with air cooling fans 19-1 to 19-3, an outside air temp. detector 17 for detecting the outside air temp. and a polarizing plate temp. detector 16 for detecting the temp. of the polarizing plate 11 installed on a liquid crystal panel 12, the air cooling fans 19-1 to 19-3 are controlled so that a difference between the temp. detected by the polarizing plate temp. detector 16 and the temp. detected by the outside air temp. detector 17 may be kept constant.