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: 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: 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 improving grey scale fidelity portrayal of pictures displayed on matrix display screens.

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.

Abstract: The invention is related two a new kind of plasma display panel control. A known principle for PDP control is based on a combination of sub-field addressing and priming. Within the priming period all the plasma cells of the panel are pre-excited by a strong voltage pulse. This treatment of the cells produces a slight background luminance which is a drawback for picture quality aspects because the achievable contrast is reduced. According to the invention it is proposed to use self-priming sub-fields (SPSF) and refreshing sub-fields (RSF) instead of this hard priming period. With these concept it is assured that the cells which ought to be black remain black. Self-priming sub-fields (SPSF) reduce or eliminate the need for priming, thus making dark areas darker, while refreshing sub-fields (RSF), can be addressed faster. In practice, the number of refreshing sub-fields (RSF) in a frame period is higher than the number of the self-priming sub-fields (SPSF).

Abstract: When the observation point on a PDP screen moves, artifacts will be introduced which are commonly described as “dynamic false contour”. A simple way to reduce this effect requires the use of more sub-fields at the expense of panel brightness. A first idea called Bit-Line-Repeat (BLR) makes it possible to exchange vertical resolution with addressing time in order to dispose of more sub-fields for the same brightness. Nevertheless, such a solution introduces some vertical artifacts mostly during movement. Therefore, before the step of sub-field encoding a vertically filtering of the picture divided into pixel blocks is performed, wherein each block includes at least one pixel in horizontal direction and a number of pixels corresponding to the number of common lines in vertical direction. The effect of the pre-filtering step is that the difference of brightness values within each pixel block is limited to a predetermined value.

Abstract: With the new plasma display panel technology new kinds of artifacts can occur in video pictures. These artifacts are commonly described as dynamic false contour effect, since they correspond to disturbances of grey levels and colors in the form of an apparition of colored edges in the picture when the observation point on the PDP screen moves. According to the invention such an artifact is compensated by analyzing the motion in the pictures assigning to each block of a picture a corresponding motion vector and performing a re-coding step in which a sub-field code word entry of a current pixel are calculated. For this purpose the motion vector is defined to point from a pixel in a previous picture to a pixel in the current picture. The sub-field code word entries for a current pixel (P8) are determined by dragging sub-field entries of the pixels lying on the motion vector trajectory.

Abstract: The invention is related two an improved addressing scheme for plasma display panel control. In the conventional addressing scheme called ADS (Adressing and Displaying Separated), the whole panel is treated as one section and the addressing period within the sub-fields is broad because all lines of the whole panel are addressed one after the other in this single addressing period. This has the drawback that a long time distance is between writing a cell during addressing phase and light generation during the sustaining period. An improved addressing scheme has been proposed in literature, where the panel is partitioned in a number of sections and correspondingly the addressing period is split up in corresponding small addressing periods for each section. Inbetween the small addressing periods there is some light generation, so that the time distance between addressing and light emission is substantially reduced.

Abstract: A signal processing method for an analogue picture signal is proposed. In this case, the analogue picture signal originates from a computing unit (10) in which the signal was generated digitally in accordance with a graphics standard such as, for example, EGA or VGA and was subsequently converted into analogue form. The method consists in subjecting the analogue picture signal to analogue/digital conversion at a first chosen sampling frequency, after which the sampled picture is then investigated for picture disturbances, in order to determine a corrected sampling frequency. Further measures relate to the determination of the optimum sampling phase and the determination of the exact position of the active picture relative to the horizontal and/or vertical synchronization pulses.