側入光式LED背光模組中燈罩內反射片與楔型導光板之距離

Abstract

本研究主要目的希望在不改變或增加成本考量下，探討薄型化側入光之LED背光模組,入光側燈罩內反射片與楔型導光板之距離，對光學輝度之影響。因薄型化導光板是近年來背光模組產業之開發、設計重點,而大多業者為達成此目的均直接採用楔型導光板，以減少厚度,滿足市場需求。 但楔型導光板之畫面區厚度減薄至所需厚度時，其LED入光側之楔型斜面,必定有部分光能量從此斜面竄出而導致光能量的損失。再加上窄邊化需求，此架構易產生LED側出現HOTSPOT之現象。若能利用燈罩中之反射片的架構，將其損失的光能量反射再利用及同時改善其HOTSPOT現象,其對畫面區之光效能是有正向之幫助的。 故本研究，利用光學模擬軟體(SPEOS)，撰寫程式，用參數化的設計,模擬架構中的反射片與楔型導光板之距離,找出最佳化架構關係，並將研究結果數據表格化,同時依照設計條件，製作樣品，量測光學數據，以驗證模擬軟體數據的正確性。經樣品量測數據與模擬數據比對後發現，此架構對光學輝度有提升之作用，且改善幅度與模擬數據接近，故此研究內容可作為未來開發參考重點。

The purpose of this study is to investigate the effect of the distance between reflector and light guide plate on the optics efficiency of a thin-edge type LED backlight module without increasing cost. For thinning light guide plate is one of the design point of backlight module, in order to satisfy the market demand, most developers choose to use wedge-type light guide plate for improving thickness problem. However, in the same time, using wedge-type light guide plate to achieve the thickness requirement of Active Area, there will be some optics energy loss from wedge side (LED side). With this kind of design, narrow-side frame are often used and the HOTSPOT happens easily in the LED side. If we can use reflector to reflect the optics energy, not only HOTSPOT can be improved but also the optics efficiency can be increased. Therefore, in this study, we use optics simulation software (SPEOS) to find out the distance between reflector and wedge-type light guide plate on the luminous efficiency of the module. A mock-up sample of the design was used for comparison of the numerical analysis with the product. After the comparison between actual sample measured data and simulation data, we found that this kind of structure would not only improve the luminance, the improvement is also close to the simulation. Therefore, this research may be regarded as a major reference for product development.