Koninklijke Philips Corporation N.V.

U.S. Philips Corporation

Franciscus Johannes Stommels

Carsten Deppe

Peter Luerkens

Antonius G Verhulst

Jeroen Hubert Christoffel Jacobus Stessen

Ulrich Boeke

Nebojsa Fisekovic

Wilbert J Hartmann

Ann M Luyckx-Smolders

A scanning backlight unit (BU) for a matrix display comprises a plurality of light sources (L, . . . , Ln). A driver () supplies drive signals (D, . . . , Dn) to the light sources (L, . . . , Ln). A controller () controls the driver () to separately activate the light sources (L, . . . , Ln) to obtain light-emitting regions () being active. A light sensor () is associated with a group of at least two of the light sources (L, . . . , Ln) to supply a sensor signal (SES) which indicates a luminance (LU) of the group. The controller () reads the sensor signal (SES) at different instants (ts, . . . , tsn) at which mutually different subsets of the light sources (L, . . . , Ln) of the group are active to control the driver () to supply power levels to the light sources (L, . . . , Ln) of the group to obtain a luminance (LU, . . . , LUn) of each one of the light sources (L, . . . , Ln) of the group in dependence on the sensor signal (SES).

Scanning backlight for a matrix display

A liquid crystal device incorporating ferroelectric liquid crystal medium having smectic layers between two supporting plates provided with electrodes, the smectic layers exhibiting a spread of angles with respect to at least one of the supporting plates, whereby a gradual transmission/voltage characteristic is achieved. The spread of angles can be obtained by any of several techniques, such as subjecting the device to a low frequency electric field, or a local thermal, mechanical, chemical or magnetic treatment.

Ferroelectric liquid crystal display having a spread of angles for

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Eindhoven, Netherlands

Franciscus Johannes Stommels