Abstract: Phosphor based display technologies show artefacts like “sticking” or “ghost” images produced by “marking” or “burn-in” effects. In order to remove these artefacts it is proposed to activate a portion of the display screen (10) as a wiper and to move the wiper at least one time over the complete display screen (10) or a part of the display screen (10). The wiper will homogenize the complete video screen in order to make the ghost images less visible.

Abstract: The invention relates to a method for optimizing brightness in a display device having a plurality of luminous elements corresponding to the pixels of a picture, wherein the time duration of a video frame or video field is divided into a plurality of sub fields during which the luminous elements can be activated for light emission with sustain pulses corresponding to a sub field code word which is used for brightness control, the total number of sustain pulses being determined in view of a selected power mode function of picture load the method including the following steps:

Abstract: In order to improve the picture quality of plasma display panels and to reduce differences to present CRTs dithering is used. However, the dithering pattern may appear on the retina for some movement having a spatio-temporal period similar to those from dithering. Therefore, it is proposed to use motion vectors coming from a motion estimator (14) in order to suppress the visibility of the dithering in case of motion. Then, for the viewer the quality of moving pictures will be similar to those obtained for static pictures.

Abstract: Plasma Display Panels (PDP) are becoming more and more interesting for TV technology. Due to the larger size of PDPs, with larger viewing angle the large area flicker effect will become more serious in the future, in particular when handling 50 Hz video standards.

Abstract: A method and an apparatus for displaying pictures with an improved grey scale portrayal shall be provided. Therefore, the quantization steps of the digitized signals for a plasma panel display have to be reduced. To achieve such reduction of quantization steps of the light output of a cell of the plasma display panel, the energy of the addressing impulse for addressing those luminous elements which have to be activated for a complete frame period or a part of it is used. Consequently, the light output of the luminous elements can be controlled by the usual sustain impulses and additionally by the addressing impulses thus reducing the quantization steps.

Abstract: The invention is related to a new kind of dithering method for plasma display panels. In a former Europena Patent Application a dithering method for the plasma display technology has been presented that utilizes a 3-dimensional dither pattern for the repeated use in a video sequence. A first dimension corresponds to a number of video frames, a second dimension corresponds to a number of video lines, and a third dimension corresponds to a number of cells or pixels in a video line. It has been found that this dither pattern has for some video levels the drawback of a generating a noticeable pattern in homogenous surfaces on the screen that reduces the picture quality. In order to overcome this drawback the invention proposes a new degree of freedom for the dither pattern. Different dither patterns are provided for different entries in a number of least significant bits of the data word representing the input video level.

Abstract: An improved addressing scheme for plasma display panel control comprises partitioning the panel into a number of sections and splitting the addressing period into correspondingly small addressing periods for each section. By varying the time distance between successive addressing periods of the sections from one sub-field to the other, at least for the sub-fields with higher weights, a better spread of the energy input and output of the plasma display panel is achieved and the power supply circuit for the display panel may be constructed with less expensive components.

Abstract: The number of available sub-fields for stereoscopic displaying on plasma display panels is not high enough to insure a good grey-scale portrayal as well as a good false contour behaviour. Thus, the number of sub-fields is artificially increased by commonly addressing the sub-fields of two or more pixel lines so that the addressing time of the panel may be decreased for each sub-field.

Abstract: With the new plasma display panel technology new kinds of artifacts can occur in video pictures due to the principle that brightness control is done with a modulation of small lighting pulses in a number of periods called sub-fields. These artifacts are commonly described as ‘dynamic false contour effect’. A technique called bit line repeat coding has been developed for reducing the false contour effect. According to this technique sub-field coding is done with common (CSF) and normal sub-fields (SF) where for the common sub-fields (CSF) identical entries in the sub-field code words of two or more corresponding pixels on two or more pixel lines are used. In this specific sub-field coding method some cases will occur in which an error has to be made due to the reduced flexibility in encoding produced by the need to have the same code on common sub-fields (CSF).

Abstract: Plasma Display Panels (PDP) are becoming more and more interesting for TV technology. Due to the larger size of PDPs, with larger viewing angle the large area flicker effect will become more serious in the future, in particular when handling 50 Hz video standards. This invention proposes a different sub-field organisation, with different coding, which reduces large area flicker artefact, and which includes grouping of sub-fields in two sub-field groups wherein the two sub-field groups are identical in terms of the most significant sub-fields and different in terms of the least significant sub-fields, and a sub-field coding process that distributes luminance weight symmetrically over the two sub-field groups so as to minimize the large area flicker luminance component.

Abstract: The invention relates to a method for processing data of video pictures for displaying the pictures on a display device like a Plasma Display Panel. The existing false contour effect compensation methods which make a false contour compensation based on shifting sub-field code word entries along the direction of the motion vector of a current pixel, produce an artifact in the pictures, in case of object crossings. In the appearing area there is a lack of light generation.

Abstract: In many cases it is not possible to reproduce enough video levels on a PDP due to timing issues or a specific solution against the false contour effect. In such cases dithering is used to render all required levels. In order to reduce the visibility of the dithering noise there is performed a common change of the sub-field organization together with a modification of the input video data through an appropriate transformation curve based on the human visual system luminance sensitivity (Weber-Fechner law).

Abstract: The invention deals with the large area flicker effect reduction in display devices like plasma display panels, in which the light output is controlled by small pulses over a whole frame period and the amount of small pulses determine the brightness of the light output. The invention proposes an adaptation of the known principle of sub-field grouping for large area flicker reduction for the specific sub-field coding process called incremental sub-field coding, in which only those sub-field code words are taken for display driving having the characteristic that there is never a sub-field inactivated between two activated sub-fields or never a sub-field is activated between two inactivated sub-fields.

Abstract: A method for power level control in a Plasma Display Panel with which the Peak White Enhancement Factor can be increased. The method includes the provision of a set of power level modes for the sub-field coding. To each power level mode a characteristic sub-field organization belongs. The sub-field organization is variable in respect to one or more of the following characteristics: the number of sub-fields the sub-field type the sub-field positioning the sub-field weight the sub-field pre-scaling a factor for the sub-field weights which is used to vary the amount of small pulses generated during each sub-field. The method includes the steps of determining a value which is characteristic for the power level of a video picture and selecting a corresponding power level mode for sub-field coding.

Abstract: The present invention relates to a method for processing video pictures for display on a display device comprising a plurality of lines constituted by luminous elements called cells corresponding to the pixels of a picture, wherein the time duration of a video frame is divided into a plurality of sub-field periods during which the cells can be activated for light emission, a sub-field period being divided into an addressing period wherein the plurality of lines is scanned line by line, a sustaining period and an erasing period, wherein, in the addressing period, the addressing time is different from one line to an other. The invention is mainly used in PDP technology.

Abstract: Since the phosphor lag effect results from the slowness of the green and red phosphors and since it is not possible to make these phosphors faster, the blue one has to be made slower in order to reduce the color trail effect. Therefore, a part of the blue component is artificially delayed. Only a certain percentage of the blue component of the actual frame is transmitted during the actual frame, whereas the rest of the blue component will be transmitted during the next frames. The dynamic false contour effect introduced by this video processing may be compensated by subfield shifting.

Abstract: In the field of video displaying the low video levels do not generate large area flicker. For displaying video sources with higher frame rate, it is therefore the idea of the invention, to extract from two corresponding pixels of two successive video frames a common portion (VX) that will be displayed at a sub-frequency fv/2 while the individual portions (V1′, V2′) of the corresponding pixels video are displayed at the correct high frequency fv. The time period for displaying two frames is divided into three sub-groups. Two groups of sub-fields with similar sizes, for displaying the individual portions (V1′, V2′) and one group of sub-fields, called extra-codes, for displaying the common portion (VX). This enables to eliminate large area flicker artifacts from PDPs, when displaying 50 Hz based video norms by using upconverted 100 Hz video sequences and to display real high frequency video on the PDP (ca. up to 120 Hz) without frame dropping.

Abstract: The present invention relates to a method for improving grey scale fidelity portrayal of pictures displayed on matrix display screens.

Abstract: The present invention relates to a method for processing video signals for display on a display panel comprising a matrix array of cells which could only be “ON” or “OFF”, wherein the time duration of a video field is divided into N sub-fields during which the cells can be activated, each sub-field comprising at least an addressing period and a sustaining period, the duration of which corresponding to the weight associated with said sub-field, said method comprising at least a priming period, characterized in that the position of the priming period is determined as follows:

Abstract: The invention is related two a new kind of pre-processing for plasma display panel control. The plasma display technology has the drawback of a reduced grey scale portrayal. This is due to the fact that contrarily to CRTs where luminance is approximately quadratic to the applied cathode voltage, luminance is linear to the number of discharge pulses in PDPs. Therefore, an approximately quadratic degamma function has to be applied to the input video signal components R,G,B before sub-field coding can be done. Truncation to 8-bit video data is required, so that the effect of the degamma function cannot be fully maintained. Especially in the region of small video levels, where the eye sensitivity is high, the grey scale portrayal is poor. According to the invention it is proposed to use a new kind of dithering, adapted to the PDP specialities to improve the grey scale portrayal. These adaptation includes three dithering specialities which can he used singly or in combination. These are: cell-based dithering, i.e.