SAFETY DEVICE FOR BACK LIGHT OF LIQUID CRYSTAL DISPLAY DEVICE

摘要

PURPOSE:To facilitate an exchange operation and to make the cost thereof lower than the cost for replacement parts by necessitating exchange of only the lamp while there is heretofore a need for exchanging a temp. fuse as well together with the lamp with the conventional constitution using the temp. fuse. CONSTITUTION:The tube wall of a light source lamp 2 for a back light of a liquid crystal display device is provided with a temp. sensitive element 3 consisting of a shape memory alloy which is reversibly deformed according to a change in the altitude of temp. and is also provided with a detecting switch 5 which is actuated by a change in this temp. sensitive element 3 when the temp. of the lamp 2 rises up at the end period of its life and an energization control circuit which stops energization to the lamp 2 by the signal from this detecting switch 5.