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Two approaches to the luminance enhancement of backlighting units for LCDs
Author(s) -
Suzuki Masaru
Publication year - 1999
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 - 10.1889/1.1984469
Subject(s) - backlight , luminance , optics , polarizer , liquid crystal display , viewing angle , collimated light , polarization (electrochemistry) , materials science , light intensity , brewster's angle , physics , birefringence , laser , chemistry , brewster
— Two approaches to the luminance enhancement of a backlighting unit for a LCD have been followed. One uses a light‐collimating sheet, which changes the light direction from an oblique angle to the normal angle, resulting in higher luminance intensity at the normal direction. By optimizing its refractive index and the apex angle, a luminance enhancement of 30% was achieved. This collimating sheet has a light distribution whose angles at half luminous intensity were the same as the LCD's viewing angles. The other approach uses a reflective polarizer sheet, which reflects one of the polarization components and recycles it to the other polarization component in order to increase the total amount of light. This sheet also has a luminance enhancement of 30%. The designs and the measured data obtained through each approach are presented.