Patent ID: 7636076

Claim:
A display panel comprising: a transflective liquid crystal display having a plurality of pixels, comprising: a first substrate having a common electrode; a second substrate; and a liquid crystal layer disposed between the first and second substrate, the liquid crystal layer comprising a plurality of layer segments associated with a plurality of pixels, wherein at least some of the pixels comprise a plurality of sub-pixels and wherein at least three of the sub-pixels are color sub-pixels and at least one of the sub-pixels is a fourth sub-pixel, and wherein each of the color sub-pixels comprises a transmission area having a transmissive electrode disposed on the second substrate and a reflection area having a reflective electrode disposed on the second substrate, and the fourth sub-pixel comprises a further electrode disposed on the second substrate, wherein the further electrode is at least partially reflective; a data input device to provide color image data to the color sub-pixels; a computation module to compute further image data for the fourth sub-pixel based on the color image data, the computation module has two or more sub-modules for computing the further image data using different algorithms; and a selector operatively connected to the computation module for selecting the algorithms, wherein one of the algorithms computes the further image data for the fourth sub-pixel based on the color image data modified by an exponential index, wherein said one algorithm has a form of Y RGB = Y R ⁢ ⁢ max ⁡ ( R ⁢ / ⁢ MAX ) gamma + Y G ⁢ ⁢ max ⁡ ( G ⁢ / ⁢ MAX ) gamma + Y B ⁢ ⁢ max ⁡ ( B ⁢ / ⁢ MAX ) gamma M = MAX * ( Y RGB Y RGB ⁢ ⁢ MAX ) 1 ⁢ / ⁢ gamma , where gamma is the exponential index greater than 1; Y Rmax , Y Gmax and Y Bmax are maximum brightness levels of the display for the color sub-pixels; Y RGBMAX is the sum of Y Rmax , Y Gmax , Y Bmax ; MAX is the maximum input signal level expressed in gray scale; M is the further image data for the fourth sub-pixel and R, G, B are color image data provided to the color sub-pixels.