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39.1: Adaptive Dimming and Boosting Backlight for LCD‐TV Systems
Author(s) -
Greef Pierre,
Hulze Hendriek Groot
Publication year - 2007
Publication title -
sid symposium digest of technical papers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.351
H-Index - 44
eISSN - 2168-0159
pISSN - 0097-966X
DOI - 10.1889/1.2785558
Subject(s) - backlight , brightness , luminance , liquid crystal display , boosting (machine learning) , contrast ratio , computer science , crts , contrast (vision) , optics , computer vision , artificial intelligence , computer graphics (images) , physics
Abstract The limited transmittance of LCD panels can be observed as a waste of energy, leading to a limited brightness. Light leaking through LCD panels driven to black, can be observed as a poor black‐level, limiting the contrast ratio. Adaptive Dimming Backlight technology can be applied to attenuate the backlight luminance, improving local contrast, black‐level and saving power. The optical crosstalk between the controllable backlight segments has a negative impact on the dimming performance, limiting the spatial backlight luminance modulation. Crosstalk Compensation can partly compensate this artifact, enhancing the spatial modulation of the segments. Adaptive Boosting Backlight technology can be applied to boost the output of the panel over 100%. This improves the local brightness and contrast for a sparkling picture, still saving power. Crosstalk compensation enables deeper dimming. Deeper dimming improves on contrast and enables more boosting for an even brighter picture. So when these technologies are combined:□ The contrast may increase up to 5 times (CCFL/EEFL). □ The brightness may double and contrast may increase up to 20 times (HCFL). □ Alternatively, for 2D‐Dimming the spatial contrast may increase up to a factor of 100 and the temporal contrast may increase to infinite (LED). At the same time, up to 50% average power can be saved!