Thermal analysis of thin film transistor liquid crystal display (TFT-LCD) TV panels with single sided LED bars

In this research thermal and fluid fields of a 32-inch commercial thin film transistor liquid crystal display (TFT-LCD) TV panel were investigated numerically and experimentally. The new trend in the production of TFT-LCD, TV panel is to have slimmer screen displays. The original design with 180 LEDs (light emitting diodes) placed at the top and bottom edges of the panels was modified. In the new design, the panels were illuminated using only 72 LEDs placed underside and inside the panels. By this modification an important cost reduction has been achieved alongside having slimmer screen displays. Heat dissipated by these 72 LEDs must be removed in order to assure good image quality and long service life. Hence an appropriate thermal management is indispensable. To analyze temperature distribution at steady state condition a CFD (computational fluid dynamics) computer code “FloEFD” was used. The results obtained from the computational analysis have been validated by using experimental techniques. For this purpose thermocouples were attached on the panel and after the steady state has been reached, temperatures have been recorded in order to compare them to the distribution obtained by “FloEFD”. Furthermore, a thermal camera image of the panel by FLIR Thermacam SC2000 test device was obtained as another validation for temperature distribution.