Koninklijke Philips Corporation N.V.

Tp Vision Holding B.v.

Signify Holding B.v.

Koninklijke Philips Electronics N.v.

Oleg Belik

Gerben Johan Hekstra

Erno Hermanus Antonius Langendijk

Michiel Adriaanszoon Klompenhouwer

Claus Nico Cordes

Dmitry Nikolaevich Znamenskiy

Nalliah Raman

Michel Cornelis Josephus Marie Vissenberg

Marcellinus Petrus Carolus Michael Krijn

Mark Jozef Willem Mertens

Martin Jacobus Johan Jak

Tommaso Gritti

Karel Johannes Gerhardus Hinnen

Stefan Marcus Verbrugh

Jurgen Jean Louis Hoppenbrouwers

Robert-Paul Mario Berretty

Petrus Johannes Mathijs Van Der Burgt

Gianluca Monaci

Hao Hu

Petrus Johannes Arnoldus Hubertus Kuijten

Lodewijk Daniella Stanslaw Hendriks

Mark J W Mertens

Erno H A Langendijk

Nathalie M D Dessaud

Jan F Stroemer

Lodewijk Daniella Stanislaw Hendriks

A method of self-calibrating a lighting device, comprising: &#x2014;monitoring a calibration area, which encompasses at least a part of an area being illuminable by the lighting device; and&#x2014;calibrating the light output settings of the lighting device. The monitoring operation includes repeating: &#x2014;detecting any relevant change, out of a set of relevant changes comprising at least a light intensity change, in the calibration area during a monitoring time, while keeping the light output of the lighting device constant; and&#x2014;determining an amount of change within the monitoring time; until the amount of change is below a limit value. Thereby the lighting device does not perform the calibration until it has detected a period of no or small changes.

Method of self-calibrating a lighting device and a lighting device performing the method

Light-emitting devices () and methods for operating light-emitting devices are disclosed. Each of the light-emitting devices () comprises a plurality of light sources (A-F) for illuminating a target (), wherein each of the light sources is configured to emit light within a predetermined color range. Each of the light-emitting devices comprises means () for automatically adjusting the spectral power distribution of light-emitted by the light-emitting device on basis of the color of the target or a region of the target illuminated by the light-emitting device, such that light emitted by the light-emitting device is made increasingly compliant or even compliant with a criteria of a predetermined color characteristics.

Light system for emphasizing objects

A method of dynamic of gamut control is provided for a display having a multi-spectral (typically multi-color) backlight, and sub-pixels corresponding to the different backlight spectra and at least one common sub-pixel. The display may f be an RGBW display having an RGB backlight. The method includes iteratively calculating the minimum required backlight intensities that will allow all (selected) color points of an image to be represented by the display. The determination for a light source of the backlight is based on determinations of intensities determined for other light sources in a previous iteration.

Dynamic gamut control for determining minimum backlight intensities of backlight sources for displaying an image

A multi-primary conversion method is disclosed for converting an input vector defining a color of an input pixel in a Linear color space into a drive vector having n components for driving 'n' display primaries of a display color space. The drive vector comprises m sub-drive vectors for driving m groups of the display primaries.

Colour conversion for a multy-primary display

A method of dynamic gamut control is disclosed. In accordance with a first aspect of the invention, control of the intensities of a set of color primaries illuminating associated sub-pixels of a display device is disclosed. Thus, the intensities of the light sources are controlled to control the intensities of the color primaries after the color filters. The method searches for a minimal intensity value of one color primary, which is adjusted to obtain together with the other color primaries of the set of color primaries an adjusted color gamut still containing all the colors of the set of colors.

Dynamic gamut control

To have an optimal use of a display for displaying particular, e.g. chromatically biased, image content, described is a method of calculating an optimal first and second backlight driving level, for a color display having a backlight which can be controlled to produce a first amount of light with a first spectrum in accordance with the first backlight driving level and a second amount of light with a second spectrum in accordance with the second backlight driving level, and the color display having a first and second light transmission valve plus color filter combination, arranged to create from the backlight spectra a respective first and second color primary light output, the chromaticity of at least one of the color primaries depending on the first and second backlight driving level, wherein the first and second backlight driving levels are determined so that a gamut of at least a part of a picture to be displayed is optimally covered by the gamut realizable by the display with the first and second backlight driving level.

Optimal backlighting determination apparatus and method

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 method is described which converts a three primary color input signal (Cx, Cy, Cz) into N drive signals (P, . . . , PN) to drive N&#x3e;3 primary colors of a multi-primary color display (). The method determines () a valid range (VS) wherein the N drive signals (P, . . . , PN) have valid values by performing the steps of (i) defining 3 functions representing 3 of the drive signals (P, P, P) as a function of the remaining N&#x2212;3 drive signal(s) (P, . . . , PN), and (ii) calculating () a common range in a space formed by the N&#x2212;3 drive signal(s) (P, . . . , PN) wherein each one of the 3 functions has valid values. The method selects () a point from the common range to determine the N drive signals (P, . . . , PN).

Method of converting signals for multi-primary color display

A method converts an input pixel (IPi) defined by three values (ri, gi, bi) of input primaries (RI, GI, BI) into N drive values (DSi) for driving N sub-pixels (SPi) of a pixel (PIi) of a display device (DD). The N drive values (DSi) have a valid range (VR) wherein their values occur. The N sub-pixels (SPi) emit light defined by N display primaries (DPi) of which at least four are independent. M resulting display primaries (RDi) are used () wherein a group of ones of the N display primaries (DPi) which are combined into a combined display primary (CDi) are replaced by the combined display primary (CDi). A first multi-primary conversion (MPC) is performed () on the input pixel (IPi) to obtain resulting drive values (DRi) for the M resulting display primaries (RDi). It is checked () whether the M resulting drive values (DRi) have values in the valid range (VR). If the resulting drive value (DRi) of at least one of the M resulting display primaries (RDi) has a value outside the valid range (VR) the method allocates () a fixed value (FVi) to the resulting drive value (DRi) outside the valid range (VR), and selects () K out of the N display primaries (DPi). The selection includes the ones of the N display primaries (DPi) which were combined into a combined display primary (CDi) but not the display primaries (DPi) associated with the resulting drive value (DRi) outside the valid range (VR). The integer K is larger than 3. Finally the method performs () a second multi-primary conversion under a constraint (CO) for the ones of the N display primaries (DPi) being combined into a combined display primary (CDi) in the first multi-primary conversion (MPC).

Multi-primary conversion

A method of redistributing an N-primary color input signal (IS) having a particular number&#x2267;4 (N) of input components (I, . . . , IN) into N-primary color output signal (OS) having the particular number (N) of output components (P, . . . , PN) under a constraint (CON). The method comprises defining (MPRC) three functions (F, F, F) representing three (P, P, P) of the output components (P, . . . , PN) as a function of the remaining N-3 output components (P, . . . , PN). Substituting (MPRC) the values of the input components (I, . . . , IN) into the three functions (F, F, F) to determine unknown coefficients (P', P&#x2032;, P&#x2032;) of the three functions (F, F, F). And, determining (MPRC) optimal values of the output components (P, . . . , PN) by applying the constraint (CON) to the three functions (F, F, F).

Redistribution of N-primary color input signals into N-primary color output signals

A method of converting a three-primary input color signal (IS) comprising three input components (R, G, B) per input sample into an N-primary color drive signal (DS) comprising N&#x2267;4 drive components (D, . . . , DN) per output sample for driving N sub-pixels (SP, . . . , SPN) of a color additive display. The N sub-pixels (SP, . . . , SPN) have N primary colors. The method comprises adding (), to three equations defining a relation between the N drive components (D, . . . , DN) and the three input components (R, G, B), at least one linear equation defining a value for a combination of a first subset of the N drive components (D, . . . , DN) and a second subset of the N-drive components (D, . . . , DN) to obtain an extended set of equations. The first subset comprises a first linear combination (LC) of 1&#x2266;M&#x3c;N of the N drive components (D, . . . , DN), and the second subset comprises a second linear combination (LC) of 1&#x2266;M&#x3c;N of the N drive components (D, . . . , DN). The first and the second linear combination are different. The method further comprises determining () a solution for the N drive components (D, . . . , DN) from the extended set of equations.

Converting a three-primary input color signal into an N-primary color drive signal

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.

Converting a three primary color input signal into four signals

A method of mapping a four primary input signal to sets of four sub-pixels of a display device, the method including sub-sampling the input samples of the four primary input signal by assigning the first, second and third input signals of a particular input sample to the first, second and third sub-pixels, producing first, second and third primary colors of a particular set of four adjacent sub-pixels, respectively, and the fourth input signal of a further input sample to the fourth sub-pixel, producing a fourth color of said particular set of the four adjacent sub-pixels, wherein the particular input sample and the further input sample are associated with adjacent positions on the display device.

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Eindhoven, Netherlands

Oleg Belik