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Capacitive effects in NLR‐matrix TV‐LCDs: III. Instability
Author(s) -
Kuijk K. E.
Publication year - 1994
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 - 10.1889/1.1984917
Subject(s) - capacitance , capacitive sensing , flicker , pixel , capacitor , signal (programming language) , diode , voltage , materials science , electrical engineering , physics , optoelectronics , computer science , optics , electrode , engineering , quantum mechanics , programming language
— In AMLCDs with two‐terminal devices (NLRs), capacitive feedthrough of the trailing edge of the row‐select signal (“kickback”) influences the just‐written pixel voltage. This kickback changes with the pixel capacitance, resulting in parametric amplification when using the normal four‐level row drive. Instability may occur if the ratio of the pixel capacitance to the NLR capacitance is lower than a certain minimum value. This theory is proven with measurements on a 1‐cm 2 pixel, using two lumped diodes with parallel capacitors as an artificial NLR. In D 2 R displays, the sign of the kickback contribution is independent of the pixel voltage. This results alternately in positive and negative feedback in the two fields, and in two different transmission‐voltage curves. In practice, this may lead to 25‐Hz flicker and a data‐dependent dc voltage across the pixel.