Premium
Capacitive effects in NLR‐matrix TV‐LCDs: II. Influence of the row signal
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 - 10.1889/1.1984916
Subject(s) - flicker , voltage , pixel , feedthrough , signal (programming language) , capacitance , liquid crystal display , capacitive sensing , voltage divider , electrical engineering , computer science , physics , optics , engineering , electrode , programming language , quantum mechanics
— Capacitive feedthrough of the trailing edge of the row‐select voltage pulse in LCD matrices with non‐linear resistances (NLRs) leads to a change of the just‐written pixel voltage. This effect is called “kickback.” It can be compensated for by changing the select‐voltage value. Because of the varying pixel capacitance, the compensation is perfect for one pixel voltage only, e.g. , mid‐grey. In NLR‐matrix LCDs with four‐level row drive, this leads to an increased pixel‐voltage range. With the right select‐voltage value and a smaller gain of the column voltage, the desired pixel‐voltage range is obtained. In D 2 R displays, which use a five‐level row‐drive signal, dc shift and 25‐Hz flicker will occur for all other pixel‐voltage values. With the right choice of the select voltages and unequal gains of the column voltage for positive and negative pixel voltages, the dc shift and 25‐Hz flicker of both black and white pixels can be made zero. Formulas are presented for the various cases.