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A monolithic segmented functional light guide for 2‐D dimming LCD backlight
Author(s) -
Käläntär K.
Publication year - 2011
Publication title -
journal of the society for information display
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 52
eISSN - 1938-3657
pISSN - 1071-0922
DOI - 10.1889/jsid19.1.37
Subject(s) - backlight , light guide , prism , materials science , optics , groove (engineering) , liquid crystal display , optoelectronics , light source , physics , metallurgy
— An edge‐lit backlight with a thin structure and 2‐D dimming function is a highlighted requirement. To achieve a thin backlight unit for 2‐D dimmable displays, a monolithic functional light‐guide plate (LGP) was segmented by using a recessed U‐groove with graded height as semi‐partitions. The height of the U‐groove controls the cross‐talk between the segments. A single segment was characterized with an array of louver‐shaped micro‐prisms that function as unilateral reflectors for light distributing, directing, and extracting. Arrays of rounded micro‐prisms, and lenticular prisms for in‐ and out‐coupling, are designed on the light injection surface and front surface of the LGP for light‐cone shaping on the BLU. The light guide has a length of 73.0 mm, a width of 40.7 mm, and a thickness of 0.7 mm. The LGP was segmented into 16 segments where the width and graded height of the recessed U‐prism between the segments is 0.020 mm and 0.10–0.50 mm, respectively. By using the monolithic light‐guide plate, the cross‐talk is suppressed to 20% and 4% at the center of first and second neighboring segments, respectively.