Koninklijke Philips Corporation N.V.

Tp Vision Holding B.v.

Nalliah Raman

Gerben Johan Hekstra

Oleg Belik

Claus Nico Cordes

Martin Jacobus Johan Jak

Jurgen Jean Louis Hoppenbrouwers

A color display device, a drive circuit for a color display device, a method, a signal and a computer-readable medium for reducing electro-optical cross talk that occurs in a display that is operated in Spectrum Sequential mode is disclosed. The invention eliminates annoying visible artifacts, such as contouring, noise, or color deviation, which normally are introduced by this cross talk by compensating for the cross talk. According to embodiments of the invention, a drive signal (R',G&#x2032;,B&#x2032;) to drive picture elements of the display is altered in video processing circuitry (MPC, XTC, SC) and/or software, in dependence on one or more properties of different spectra from a light source () in the display. The invention is implemented with little extra effort and cost in known LCD displays.

Spectrum sequential display having reduced cross talk

A dual display device for displaying an input image includes first and second displays. The first display is arranged for modulating an image from the second display. The dual display device further includes a processor having an image splitter which splits the input image into illumination and reflection images according to a retinex algorithm. The reflection image is displayed on the first display and the illumination image is displayed on the second display. Due to the series arrangement of the two displays, the input image is substantially recreated. The illumination image typically is a spatially low-resolution image derived from the input image.

Dual display device

A method of enhancing details in an input image. The input image comprises input pixels, which have input pixel values (IPV) limited to a range (RA). The method comprises average filtering () the input pixel values (IPV) to obtain average brightness values (LV). A luminance mask is applied () to the average brightness values (LV) to obtain masked values (MV) which are different for average brightness values (LV) in a sub-range (SR) of the range (RA) than for pixels outside the sub-range (SR). The input pixel values (IPV) are detail filtered () to obtain detail values (HV) indicative for an amount of detail. A non-linear function (NLF) is applied () on the input pixel values (IPV) to obtain for each input pixel value (IPV) a corresponding output pixel value (OPV). A gain of the non-linear function (NLF) is dependent on both the masked value (MV) and detail value (HV) which both are determined for the particular input pixel. The gain is higher for input pixels with input pixel values (IPV) outside the sub-range (SR) than for input pixels with input pixel values (IPV) inside the sub-range (SR). And the gain is higher for input pixels for which the detail value (HV) indicates more high frequency content in the image portion around the particular input pixel than for input pixels for which the detail value (HV) indicates less high frequency content.

Image detail enhancement

The display device (DD) comprises an adjustable light source (BL), a display panel (DP) with display pixels for modulating light originating from the light source (BL) and processing circuitry (P) coupled to the display panel (DP) and the light source (BL). The processing circuitry (P) has an input for receiving an input signal (V) representing gray levels of pixels of an image to be displayed on the display panel (DP). The processor (P) comprises:

Display device comprising an ajustable light source

A method of converting a three primary color input signal into a four primary color drive signal, includes defining three functions representing the first, second, and third drive signals as a function of the fourth drive signal, determining the intersection values of the fourth drive signal at a set of intersections of the three functions mutually, and of the three functions and a line defined by the fourth drive signal being equal to itself, determining boundary values of a valid range of the fourth drive signal in which all drive signals have valid values, determining calculated values of the first, second and third drive signals at the intersection values and the boundary values, calculating the maximum value (Vmax) or minimum value (Vmin) of the calculated values at the intersection, and selecting the intersection value at which the maximum value or minimum value is minimum or maximum, respectively.

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Singapore, Singapore

Nalliah Raman