[[alternative]]Optical Design of Direct Backlight Modules with White LEDs

碩士電機工程學系[[abstract]]本論文主要利用光學軟體LightTools設計17吋與30吋液晶顯示器直下式背光模組，所設計的背光模組採用高功率白光LED光源並結合倒立的錐形圓柱體結構以及導光板與網點之設計，使由LED光源所發射的光線可均勻地分佈於背光模組中。設計與模擬的結果分別以5點與9點兩種量測方法的量測值進行分析與比較本論文所設計的背光模組與未設計的背光模組的輝度與照度均勻度。由模擬結果顯示，本論文所設計的背光模組（17吋）以5點量測法所得到之輝度均勻度與照度均勻度分別為89.94%與92.67%，9點量測法所得到之輝度均勻度與照度均勻度分別為84.32%與88.25%；未設計的背光模組以5點量測法所得到之輝度均勻度與照度均勻度分別為71.04%與73.81%，9點量測法所得到之輝度均勻度與照度均勻度分別為72.45 %與71.58 %。故本論文所設計的背光模組較未設計的背光模組的無論在輝度與照度的均勻度均高出約20 %以上。 關鍵詞： 背光模組、導光板、白光LED、光學設計、均勻度。[[abstract]]This thesis mainly utilizes an optical software, LightTools, to design the designed backlight modules (BLMs) for a 17-inch and 30-inch LCDs. The BLMs use an upside-down cone-shaped structure, which is placed above each LED light source, combined with a designed sideward light-guide structure and dot pattern that the light rays can be uniformly distributed in the BLMs. The design and simulation results are used to analyze and compare the averaged luminance and illuminance uniformity of the BLMs between the designed and undesigned modules by using the 5-point, and 9-point measurement technologies, respectively. The simulation results show that the averaged luminance and illuminance uniformities of the designed BLMs (for 17-inch panel) are 89.94% and 92.67%, respectively, based on the 5-point measurement, and are 84.32% and 88.25%, respectively, based on the 9-point measurement. On the other hand, the averaged luminance and illuminance uniformities of the undesigned BLMs are 71.04% and 73.81%, respectively, based on the 5-point measurement, and are 72.45% and 71.58%, respectively, based on the 9-point measurement. Thus the averaged luminance and illuminance uniformity of the designed BLMs in this thesis are superior to those of undesigned BLMs with 20% and up. Keywords: backlight module, light guide plat, white LED, optical design, uniformity