Passive matrix addressing is an addressing scheme used in early LCD displays. This is a matrix addressing scheme meaning that only m + n control signals are required to address a m × n display. A pixel in a passive matrix must maintain its state without active driving circuitry until it can be refreshed again.
The signal is divided into a row or select signal and a column or video signal. The select voltage determines the row that is being addressed and all m pixels on a row are addressed simultaneously. When pixels on a row are being addressed, a Vsel potential is applied, and all other rows are unselected with a Vunsel potential. The video signal or column potential is then applied with a potential for each m columns individually. An on-lighted pixel corresponds to a Von, an off-switched corresponds to a Voff potential.
The potential across pixel at selected row i and column j is
and
for the unselected rows.
Passive matrix addressed displays such as ferroelectric liquid crystal displays do not need the switch component of an active matrix display because they have built-in bistability. Technology for electronic paper also has a form of bistability. Displays with bistable pixel elements are addressed with a passive matrix addressing scheme, whereas TFT LCD displays are addressed using active addressing.
Famous quotes containing the words passive, matrix and/or addressing:
“She has taken her passive pigeon poor,
She has buried him down and down.
He never shall sally to Sally
Nor soil any roofs of the town.”
—Gwendolyn Brooks (b. 1917)
““The matrix is God?”
“In a manner of speaking, although it would be more accurate ... to say that the matrix has a God, since this being’s omniscience and omnipotence are assumed to be limited to the matrix.”
“If it has limits, it isn’t omnipotent.”
“Exactly.... Cyberspace exists, insofar as it can be said to exist, by virtue of human agency.””
—William Gibson (b. 1948)
“But what is quackery? It is commonly an attempt to cure the diseases of a man by addressing his body alone. There is need of a physician who shall minister to both soul and body at once, that is, to man. Now he falls between two stools.”
—Henry David Thoreau (1817–1862)