Patent ID: 8144093

Claim:
A display device comprising a liquid crystal display panel for displaying an image by spatial light modulation, and circuitry for switching liquid crystal in the panel between having a first configuration in a first mode to cause an image displayed using the panel to be discernible from a wide range of viewing angles, and having a second configuration in a second mode to cause an image displayed using the panel to be discernible substantially only from within a narrow range of viewing angles, wherein an image is represented by a plurality of image elements, and the display device further comprises means for modifying the respective data values of at least some of the image elements such that when the modified image is displayed in a first scenario using a display panel having a first data value-to-luminance response to a viewer, the image perceived by the viewer through spatial averaging is substantially the same as the original image, and such that when the modified image is displayed in a second scenario using a display panel having a second data value-to-luminance response to a viewer, different to the first data value-to-luminance response, the image perceived by the viewer through spatial averaging is different to the original image, and wherein the first and second configurations of liquid crystal are arranged to provide the display panel with substantially the first and second data value-to-luminance responses respectively for viewing angles outside the narrow range, and are both arranged to provide substantially the first data value-to-luminance response for viewing angles inside the narrow range.