DE102009016420A1 - Apparatus for driving pixels of display unit in vehicle, comprises backlight, where white sub-pixels and backlight are controlled independently of one another according to brightness information - Google Patents

Abstract

The apparatus comprises a backlight (405), where white sub-pixels and the backlight are controlled independently of one another according to brightness information. The sub-pixels contain multiple colors, which include red, green and blue. The backlight is equipped with a light source, particularly a cold cathode tube or a light emitting diode. An independent claim is also included for a method for driving of pixels.

Description

The The invention relates to a device and a method for driving a pixel as well as a display with several such pixels and one Vehicle with at least one such display.

It It is known that displays or displays backlighting using Cold cathode tubes or Have light emitting diodes (LEDs). A brightness of the backlight can over a pulsed current signal (eg via a pulse width modulation, PWM). By varying the pulse width is the brightness The backlight is adjustable and can be used in ambient light conditions be adjusted. This approach is different for different electronic Display method applicable.

The Setting the brightness of the backlighting can be, for example by means of evaluation of a signal detected by a photocell respectively. The photocell detects an increased ambient brightness, the Brightness of the display can be adjusted to a higher setpoint be set.

One Display preferably has a plurality of pixels (pixels) on, each comprising a plurality of subpixels. The brightness of a Subpixels can be automatically dependent rise from the incident ambient light. This will be done achieved that a portion of the pixel is designed as a mirror (transflexive Pixel technology). The incident light of the environment is in the Pixel reflects and guides automatically to increase the brightness of the pixel in proportion to one for the pixel adjusted gray level and the incident ambient light.

It is also known that a display employs a plurality of pixels for image display. This total number of pixels indicates the resolution of the display. A single pixel may have three subpixels corresponding to the primary colors red (R), green (G), and blue (B). By controlling the individual subpixels over any number of brightness levels (gray levels), wherein, for example, the brightness levels are defined in proportion to the voltage in a gamma curve, the color mixing of the primary colors R, G and B generates an arbitrary color for the pixel. An exemplary pixel structure for an RGB pixel with the three subpixels R, G, and B is shown in FIG 1A shown.

By adding another subpixel to the device according to FIG 1A creates a pixel structure with four subpixels according to 1B wherein the added one is a white subpixel, whereby a basic brightness of the pixel can be raised in proportion to the brightness of the white subpixel (WSP). The WSP is also controlled via selectable brightness levels; here, too, the proportionality can be stored in the form of a gamma curve or a table. The control of the individual pixels is independent of each other and proportional to the respective controlled color value.

• (a) Das RGB Pixel hat drei Subpixel, das RGBW Pixel hat vier Subpixel. Damit ist bei gleicher Auflösung bzw. bei gleicher Pixelgröße die Fläche und damit eine mögliche Transmission der einzelnen RGB-Subpixel im Falle des RGBW Pixels reduziert. Eine für die Ablesbarkeit erforderliche Helligkeit eines farbigen Pixels wird erhöht durch ein Beimischen eines digital steuerbaren Weißanteils aus dem weißen Subpixel (WSP). Die Beimischung des Weißanteils führt allerdings zu einer Abschwächung des Farbanteils des Pixels, also einer ”Entsättigung” oder Abschwächung der Farbe. Bei einer gleichzeitigen Darstellung unterschiedlicher Farben auf dem Display führt dies zu einer Verringerung des Farbkontrastes zwischen den einzelnen Farben und damit zu einer schlechteren Erkennbarkeit des dargestellten Bildinhaltes.
• (b) Bei einer seitlichen Betrachtung des Displays (im Fahrzeug aus einer Fahrerperspektive bzw. einer Beifahrerperspektive) wird der vorstehend beschriebene Effekt der Entsättigung der Farben zusätzlich verstärkt durch ein Durchscheinen des weißen Subpixels auf die benachbarten Subpixel. Die unterschiedlichen Farben werden verwaschen bzw. mit reduziertem Farbkontrast zueinander wahrgenommen.
• (c) Die Farbdarstellung auf einem Liquid Crystal Display (LCD) mit RGBW-Technologie ist gegenüber einem konventionellen RGB-LCD bei gleicher Bildquelle verfälscht, da der zusätzliche Weißanteil abhängig von der dargestellten Graustufe (einstellbar) beigemischt wird. Es wird so ein neuer Farbraum geschaffen, der mit RGB-LCDs nicht darstellbar ist. Somit kann bei gleichzeitiger Verwendung dieser beiden Technologien ohne aufwändige zusätzliche Maßnahmen (z. B. eine Farbkorrektur über Veränderung der RGB-Gammakurven, Farbanpassungen an der Grafikquelle) keine einheitliche Bilddarstellung erreicht werden. Diese uneinheitliche Farbabbildung wird aber z. B. in einem Fahrzeug als störend empfunden.

The well-known RGBW pixel 1B has the following disadvantages:

• (a) The RGB pixel has three subpixels, the RGBW pixel has four subpixels. Thus, with the same resolution or with the same pixel size, the area and thus a possible transmission of the individual RGB subpixels in the case of the RGBW pixel is reduced. A brightness of a colored pixel required for readability is increased by adding a digitally controllable white component from the white subpixel (WSP). The admixture of the white portion, however, leads to a weakening of the color component of the pixel, ie a "desaturation" or attenuation of the color. With a simultaneous display of different colors on the display, this leads to a reduction of the color contrast between the individual colors and thus to a poorer recognizability of the displayed image content.
• (b) In a side view of the display (in the vehicle from a driver's perspective or a passenger's perspective), the above-described effect of the desaturation of the colors is additionally enhanced by a show through of the white subpixel on the adjacent subpixels. The different colors are washed out or perceived with reduced color contrast to each other.
• (c) The color representation on a Liquid Crystal Display (LCD) with RGBW technology is falsified compared to a conventional RGB LCD with the same image source, since the additional white component is added depending on the displayed gray level (adjustable). It creates a new color space that can not be displayed with RGB LCDs. Thus, with simultaneous use of these two technologies without complex additional measures (eg, a color correction via changing the RGB gamma curves, color adjustments to the graphics source) can not be achieved uniform image representation. This inconsistent color image but z. B. felt in a vehicle as disturbing.

The The object of the invention is the disadvantages mentioned above to avoid and in particular to provide a solution that efficiently preferably color-contrasty display on RGBW displays.

This object is achieved according to the features of the independent claims. Further Formations of the invention will become apparent from the dependent claims.

• – bei der das Pixel ein weißes Subpixel umfasst,
• – bei der eine Hinterleuchtung vorgesehen ist,
• – wobei abhängig von einer Helligkeitsinformation das weiße Subpixel und die Hinterleuchtung abhängig voneinander ansteuerbar sind.

To achieve the object, a device is specified for driving a pixel,

• In which the pixel comprises a white subpixel,
• - in which a backlight is provided,
• - Wherein depending on a brightness information, the white subpixel and the backlighting can be controlled depending on each other.

Consequently can dependent on the brightness information the white subpixel and the backlight be controlled. In particular, the white subpixel and the backlighting dependent on controlled by each other.

hereby Is it possible, that the backlight and the white subpixel depend on each other an ambient brightness are adjustable, and in particular at A bright environment can have a high driving of the white subpixel and at the same time one opposite a pixel without white Subpixel reduced control of the backlighting done. This has the advantage that the backlighting saves energy and resources can be used.

in this connection be mentioned that the device can drive a plurality of pixels, wherein each of the pixels is also a white one Subpixel includes. In particular, only a part of the amount of driven Pixel a white Subpixels include. The white subpixels can for example about the area of a display with a plurality of pixels (eg evenly spaced) so that with the driving of the white subpixels an approximately uniform increase in brightness the display is perceptible.

insofar can several white ones Subpixels be present, which can be controlled by the device are.

at the white Subpixels may be any part of a pixel or Acting displays that essentially provides a contribution to brightness and can be controlled by means of said device.

The Brightness information can be ambient brightness. Especially the brightness information can take into account a direction of light. This can be achieved, for example, by multiple light sensors are provided, which at different positions, for. B. one Cars, are arranged and by means of which it is determined from which In the direction of light. Accordingly, a display can be controlled depending on the incident light position so that the user has an optimized readability.

alternative the brightness information can comprise a color spectral component, which is taken into account in the control of the pixel.

The Activation of the pixel comprises the activation of the white subpixel dependent on from the brightness information and the control of the backlighting. additionally can the activation dependent from the temperature or from other environmental influences, e.g. From aging individual display components (eg LEDs).

Furthermore can other subpixels of the same pixel are driven. As above mentioned, can Also, a variety of pixels are addressed, at least partly a white one Subpixels have.

• – mindestens je ein Subpixel für jede der Farben rot, grün, blau und/oder
• – mindestens je ein Subpixel für jede der Farben rot, grün, insbesondere zwei grüne und ein rotes Subpixel

umfasst.One training is that the pixel

• At least one subpixel for each of the colors red, green, blue and / or
• At least one subpixel for each of the colors red, green, in particular two green and one red subpixel

includes.

A Another training is that the pixel is part of a display is.

Especially It is a training that the backlighting at least one Bulb comprises, in particular at least one cold cathode tube and / or at least one light-emitting diode, wherein the at least one light-emitting means can be controlled by means of a pulse width modulation.

Also It is a development that the white subpixel is proportional to the backlighting is controllable.

Further It is a training that the white subpixel and the backlight can be controlled by a characteristic.

Especially can be stored a characteristic that the driving ratio of white Subpixel and backlighting determined, especially depending from the brightness information, in particular the ambient brightness.

in the Framework of an additional Continuing education is the brightness information based on at least one Light sensor, in particular at least one photocell and / or Photodiode, detectable.

A next Further development is that the brightness information a Color information includes a display.

Especially can change the color information of the display to adjust the white subpixel or backlighting.

A Design is that the white subpixel and the backlight dependent can be controlled by a control signal.

at the control signal is in particular a signal of a Operating unit, in which a user a display mode (eg. B. high color contrast) can pretend.

A alternative embodiment is that the white Subpixels over a gamma curve is controllable.

A next Embodiment is that the white subpixel depends on at least one gamma curve of at least one further subpixel controllable is.

Especially can the gamma curves of the subpixels R, G and B in the control of the white subpixels considered become.

Also It is an embodiment that the white subpixel in or in front of you Active matrix is arranged.

A Continuing education is that the white subpixel as an additional Light source or is designed as a pixel border.

The The above object is also achieved by means of a display with several pixels that can be controlled by means of the device described here are.

Also becomes the solution the above object proposed a vehicle comprising at least a display as described here.

Corresponding The mentioned display can be present in almost any devices be, z. In a mobile display device, a PDA (Personal Digital Assistant), a mobile phone, an MP3 player or a Laptop.

• – bei dem das Pixel ein weißes Subpixel umfasst,
• – bei dem eine Hinterleuchtung vorgesehen ist,
• – wobei abhängig von einer Helligkeitsinformation das weiße Subpixel und die Hinterleuchtung abhängig voneinander angesteuert werden.

The above object is further achieved by a method for driving a pixel,

• In which the pixel comprises a white subpixel,
• - in which a backlight is provided,
• - Wherein depending on a brightness information, the white subpixel and the backlighting are controlled depending on each other.

In The following figures illustrate the invention with reference to exemplary embodiments schematically described. It can for better clarity identical or equivalent elements with the same reference numerals be provided.

It demonstrate

2 an example of a color contrast between blue and gray in the case of a change in the transmission of the WSP for an RGBW pixel or for a display with a large number of RGBW pixels;

3 exemplarily a transmission curve of the WSP as a function of a PWM setpoint of the backlight;

4 a block diagram for driving a display with backlighting, wherein the display has a plurality of pixels, which pixels at least partially comprise a white subpixel.

Of the The approach presented here allows a mixed proportion of white a white one Subpixels (WSP) by reducing the transmission of the WSP to optimize such that a color falsification or a contrast deterioration is reduced or minimized.

Preferably while the gamma curve of the insert is retained, there is no change the gray scale drive or the number of gray scales. Much more can one available standing voltage range for limited the WSP and therefore the entire available standing transmission to be limited upwards.

2 shows by way of example a representation of a color contrast between blue and gray in a change in the transmission of the WSP for a RGBW pixel or for a display with a plurality of RGBW pixels. The optimum color contrast is achieved at 0% transmission of the insert.

in this connection However, it is disadvantageous that such a greatly reduced Transmission of the WSP reduces the brightness of the display and so that its readability z. B. in bright surroundings (daylight, direct incident light) is. Furthermore, a transmission of the WSP of 0% causes a reduction the effective luminous area the display (the area required by the WSP is unused in this case), a bright environment has to be done by means of a backlight (also referred to as backlight or backlight), which then disproportionately is driven high and a significant warming and possibly leads to a reduction of the display.

In that regard, it is hereby proposed that the transmission of at least one WSPs dependent is designed by the height of the control of the backlight. In particular, the design can be made such that the transmission of the at least one WSPs is proportional to the control of the backlight.

• (1) Bei niedriger Umgebungshelligkeit (z. B. bei Nacht, Dämmerung oder innerhalb von Gebäuden) ist die erforderliche Leistung für die Hintergrundbeleuchtung gering. Entsprechend niedrig ist ein Sollwert der Pulsweitenmodulation (PWM). In diesem Szenario kann die Transmission des WSP beliebig bis auf 0% verringert werden. Damit ist die Farberscheinung des RGBW Displays optimiert und auch vergleichbar zu anderen RGB Displays.
• (2) Bei heller Umgebung (Tag, Sonnenschein, Anwendungen im Freien) ist eine hohe Helligkeit des Displays erforderlich um eine gute Ablesbarkeit für den Benutzer zu gewährleisten. Entsprechend wird die Hintergrundbeleuchtung hell eingestellt (hoher Sollwert der PWM). Die Transmission des WSP kann beliebig einstellbar bis auf 100% erhöht werden. Somit wird die Helligkeit des Displays erhöht und eine Überhitzung kann vermieden werden durch Anpassung des Sollwerts der PWM für die Hintergrundbeleuchtung. Mit anderen Worten, durch die Erhöhung der Transmission des WSP kann die Hintergrundbeleuchtung reduziert und somit eine Überhitzung des Displays verhindert werden. Eine weitere Optimierung kann derart erfolgen, dass ein Umschalten des WSP an eine Bildumschaltung gekoppelt ist. Auch kann die Umschaltung oder Veränderung des WSP mit einer Frame-Frequenz (z. B. 60 Hz) der auf dem Display dargestellten Bilder synchron durchgeführt werden. Damit kann erreicht werden, dass die durch die Veränderung des WSP durchgeführte Bildveränderung auf dem Display für einen Nutzer kaum auffällt. Das WSP sorgt für eine ausreichend helle Darstellung des Bildinhaltes auch ohne die maximale Ansteuerung der Hintergrundbeleuchtung. Eine Verschlechterung des Farbkontrasts kann zugunsten der Ablesbarkeit gerade in Szenarien heller Umgebung hingenommen werden. So reagiert das menschliche Auge bei hoher Umgebungshelligkeit weniger empfindlich auf Unterschiede in der Farberscheinung. (3) Auch können eine beliebige Anzahl von Transmissionswerten des WSP in Abhängigkeit des PWM Wertes anhand einer Kennlinie festgelegt bzw. vorgegeben werden. Hierdurch kann ein fließender Übergang zwischen den Szenarien (1) und (2) erreicht werden. 3 zeigt beispielhaft eine Transmissionskurve des WSP in Abhängigkeit von einem PWM-Sollwert der Hintergrundbeleuchtung. So beträgt die Transmission des WSP 0% in einem Bereich von 0 bis 60 des PWM-Sollwerts, 10% in einem Bereich von 70 bis 90 des PWM-Sollwerts, 30% in einem Bereich 100 bis 130 des PWM-Sollwerts und 100% in einem Bereich ab 140 des PWM-Sollwerts. Eine derartige Kennlinie kann in einem Speicher hinterlegt sein und abhängig von der Umgebungshelligkeit können die Transmission des WSP sowie der PWM-Sollwert eingestellt werden. Die Umgebungshelligkeit kann beispielsweise mittels eines Lichtsensors oder mehrerer Lichtsensoren festgestellt werden.
• (4) Die Transmission des WSP kann eingestellt werden in Abhängigkeit von mindestens einer der folgenden Signale (insbesondere proportional zu mindestens einem der folgenden Signale): – Ein PWM Wert; – eine Umgebungshelligkeit, die z. B. anhand eines CAN Signals einer zentralen oder einer beliebigen Photozelle in einem Fahrzeug bereitgestellt wird, wobei auch mehrere Photozellen ausgewertet werden können; eine Photozelle kann z. B. in einem Steuergerät vorgesehen sein oder es kann jedwede andere Quelle zur Detektion der Umgebungshelligkeit eingesetzt werden; – ein Farbwert des Bildinhaltes (z. B. helle Farben, dunkle Flächen, TV Bild, farbechte Darstellungen); – ein beliebiges Steuersignal, das z. B. mittels einer Bedieneinheit (z. B. einer Fernbedienung) selektierbar ist, wobei beispielsweise ein Modus mit optimiertem Farbkontrast (”Medizin-Modus”) darstellbar ist; die Auswahl des Steuersignals kann beispielsweise mittels eines Schiebereglers erfolgen, auch ist es möglich, eine Farboptimierung nach Kundenwunsch vorzunehmen.

In particular, the following scenarios are possible:

• (1) When the ambient brightness is low (eg, at night, dusk, or inside buildings), the required power for the backlight is low. Correspondingly low is a desired value of the pulse width modulation (PWM). In this scenario, the transmission of the WSP can be arbitrarily reduced to 0%. Thus, the color appearance of the RGBW display is optimized and also comparable to other RGB displays.
• (2) In a bright environment (day, sunshine, outdoor applications), high brightness of the display is required to ensure good readability for the user. Accordingly, the backlight is set bright (high PWM set point). The transmission of the WSP can be increased as desired up to 100%. Thus, the brightness of the display is increased and overheating can be avoided by adjusting the setpoint of the backlight PWM. In other words, increasing the transmission of the WSP can reduce backlighting and prevent overheating of the display. Further optimization can be carried out such that a switching of the WSP is coupled to a picture switching. Also, switching or changing the WSP can be performed synchronously with a frame frequency (for example, 60 Hz) of the images displayed on the display. This makes it possible to ensure that the image change made on the display by the change in the WSP is hardly noticeable to a user. The WSP ensures a sufficiently bright representation of the image content, even without the maximum control of the backlight. A deterioration of the color contrast can be tolerated in favor of the readability, especially in scenarios of bright environment. Thus, the human eye reacts less sensitively to differences in the color appearance with high ambient brightness. (3) It is also possible to set or specify any number of transmission values of the WSP as a function of the PWM value using a characteristic curve. As a result, a smooth transition between the scenarios (1) and (2) can be achieved. 3 shows by way of example a transmission curve of the WSP as a function of a PWM setpoint of the backlight. Thus, the transmission of the WSP is 0% in a range of 0 to 60 of the PWM setpoint, 10% in a range of 70 to 90 of the PWM setpoint, 30% in a range 100 to 130 of the PWM setpoint, and 100% in a range from 140 of the PWM setpoint. Such a characteristic can be stored in a memory and, depending on the ambient brightness, the transmission of the WSP and the PWM setpoint can be set. The ambient brightness can be determined, for example, by means of a light sensor or a plurality of light sensors.
• (4) The transmission of the WSP can be adjusted as a function of at least one of the following signals (in particular proportional to at least one of the following signals): a PWM value; - An ambient brightness, the z. B. is provided based on a CAN signal of a central or any photocell in a vehicle, with multiple photocells can be evaluated; a photocell may, for. B. be provided in a controller or it can be used any other source for detecting the ambient brightness; - a color value of the picture content (eg bright colors, dark areas, TV picture, color-fast representations); - Any control signal z. B. by means of an operating unit (eg., A remote control) is selectable, for example, a mode with optimized color contrast ("medicine mode") can be displayed; the selection of the control signal can be done for example by means of a slider, it is also possible to make a color optimization according to customer requirements.

The Control of the transmission of the WSP can be digital, z. B. by means of a Selection table or a matrix, analog or via a distortion of the gamma curve of the WSP.

Of the Transmittance value of the WSP can be compared with the gamma curves of the R, G, B subpixels be linked. This link can be realized in analogue or digital technology. Consequently the transmission value of the WSP can be (additionally) dependent on the RGB subpixels are set.

• – analoges oder digitales RGB-Display oder RGG-Display,
• – pentile Matrix,
• – monochromes Display,
• – transmissives oder transflektives Display,
• – ein reflektives Display;
• – TFT- oder CRT-Display,
• – LED-Display,
• – MEMS,
• – Projektionsdisplays.

The approach presented here is applicable to any display technologies with a pixel structure, e.g. B .:

• - analog or digital RGB display or RGG display,
• Pentylene matrix,
• - monochrome display,
• - transmissive or transflective display,
• - a reflective display;
• - TFT or CRT display,
• - LED display,
• - MEMS,
• - Projection displays.

Especially the approach shown here is arbitrary can be arranged subpixels with a white component or a brightness-enhancing Share applicable. The subpixel may be placed in or in front of an active matrix It may be as additional Light source or be designed as a pixel border.

The geometric shape of the pixel as well as the subpixel is arbitrary, too only part of the pixels can have a WSP.

4 shows a block diagram for controlling a display 404 with a backlight 405 , where the display 404 a plurality of pixels, which pixels at least partially each comprise a white subpixel.

A control unit 403 controls the subpixels of the pixels via the lines R, G, B, W, for example, the pixels are RGBW pixels. A large number of pixels gives the resolution of the display 404 , Also controls the control unit 403 via a PWM signal the backlight of the display 404 at. The control of the display 404 (ie the pixels, especially the white subpixels) and the backlighting 405 takes place in dependence on an ambient brightness emitted by the control unit 403 by means of two light sensors LS 401 . 402 is determined. Furthermore, an operating unit 406 provided by means of which z. B. a user input for setting and / or adjustment of the color contrast of the display (possibly, depending on the brightness of the environment) can be made.

Other advantages:

Of the approach presented here a cost saving by a reduced dimensioning of the Backlighting (eg by saving the backlighting required LEDs). At the same time, an image performance, in particular a color contrast dependent significantly improved by the ambient brightness.

By The reduced burden of backlighting can shorten the lifespan of the display can be increased. Also, by the changed Design and / or use of backlighting a significant energy savings be achieved.

One Another advantage is that a vote between optimized Color adjustment and optimized image brightness or readability individually adjustable. The setting can be adjusted by means of an operating or control unit or made customer-specific.

Also It is an advantage that the transmission of the insert is adjustable is that different display technologies have a uniform appearance (eg a same or similar Color saturation) have, without that complex activities would be required at the graphics source itself.

List of abbreviations:

• CRT

  Cathode ray tube, cathode ray tube

  LCD

  Liquid Crystal Display, liquid crystal display

  LED

  Light Emitting Diode, led

  MEMS

  Microelectromechanical Systems

  PWM

  Pulse Width Modulation

  RGB

  red, green, blue

  RGBW

  red, green, blue, White

  RGG

  red, green, green

  TFT

  Thin-film transistor, thin-film transistor

  WSP

  white subpixel

Claims (16)

Device for driving a pixel, in which the pixel comprises a white subpixel (W), in which a backlight ( 405 ) is provided, - depending on a brightness information ( 401 . 402 ) the white subpixel (W) and the backlight ( 405 ) are dependent on each other controllable. The device of claim 1, wherein the pixel comprises - at least one subpixel each for each of the colors red, green, blue; - at least one subpixel each for each of the colors red, green. Device according to one of the preceding claims, in the pixel is part of a display. Device according to one of the preceding claims, in the backlight comprises at least one light source, in particular at least one cold cathode tube and / or at least one light-emitting diode, wherein the at least one Illuminant means of a pulse width modulation can be controlled. Device according to one of the preceding claims, in the white one Subpixel is proportional to the backlighting controllable. Device according to one of the preceding claims, in which the white subpixel and the Hin terleuchtung are controlled by a characteristic curve. Device according to one of the preceding claims, in the brightness information based on at least one light sensor, in particular at least one photocell and / or photodiode, detectable is. Device according to one of the preceding claims, in the brightness information is color information of a display includes. Device according to one of the preceding claims, in the white one Subpixel and backlight depending on a control signal are controllable. Device according to one of the preceding claims, in the white one Subpixels over a gamma curve is controllable. Apparatus according to claim 10, wherein the white subpixel dependent controlled by at least one gamma curve of at least one further subpixel is. Device according to one of the preceding claims, in the white one Subpixel is arranged in or in front of an active matrix. Device according to one of the preceding claims, in the white one Subpixels as an additional Light source or is designed as a pixel border. Display with multiple pixels based on the device according to one of the preceding claims are controllable. Vehicle comprising at least one display according to claim 14th Method for driving a pixel, - in which the pixel is a white one Includes subpixels, - at which a backlight is provided - wherein depending on a brightness information the white Subpixels and the backlighting are dependent on each other become.