Abstract: A color display device (1) comprises a plurality of picture elements (3, 4, 5), the plurality of picture elements having a viewing side (5) and a rear side (6). Each picture element includes a light valve (7, 8, 9). The display device comprises a switchable part (12, 13) for selectively directing light of a first color and light of a second color through the light valve from the rear side to the viewing side. Each light valve comprises a first and a second switchable color filter (17, 19) having a transmittance for a third color and a fourth color, respectively, and arranged in succession in the path of the light.

Abstract: The display device (6) comprises a display (2) and generating means (10,8). The display (2) has a plurality of light emitting elements (3), and data lines (13) for providing pulse width modulation (PWM) signals to the light emitting elements (3). The generating means (10, 8) are coupled to the data lines (13) for generating, during time intervals (SF) of a frame period, at least a first non-zero emission level (L(V1; C1; I1)) of a light emitting element (3) during a first one of the time intervals (SF) and a second non-zero emission level (L(V2; C2; 12)) during a second one of the time intervals (SF).

Abstract: A colour display device (1) comprises a plurality of picture elements (3, 4, 5), the plurality of picture elements having a viewing side (5) and a rear side (6). Each picture element includes a light valve (7, 8, 9). The display device comprises a switchable part (12, 13) for selectively directing light of a first colour and light of a second colour through the light valve from the rear side to the viewing side. Each light valve comprises a first and a second switchable colour filter (17, 19) having a transmittance for a third colour and a fourth colour, respectively, and arranged in succession in the path of the light.

Abstract: The invention relates to a display device comprising a plurality of light emitting elements (1), wherein at least one of the elements has an associated capacitor (C1). The display device comprises pre-charging means (7;8) for generating a pre-charge signal for charging the associated capacitor (C1) at least partly. The pre-charging means (7;8) are adapted for generating a pre-charge signal comprising at least a first pre-charge signal in a first pre-charge stage and a second pre-charge signal in a second pre-charge stage. The pre-charge signal preferably comprises a current pre-charge signal followed by a voltage pre-charge signal. The combined pre-charge signal has the advantage of fast, but accurate pre-charging.

Abstract: A display device, such as an electroluminescent display device, includes a matrix of pixels, each pixel being driven by a drive pulse that is pulse width modulated. The width of the drive pulse is controlled by a gamma correction device, in which gamma correction information is supplied in the form of a separate pulse distribution-modulated signal.

Abstract: To suppress dissipation in monochrome LED displays, each frame is supplied at half the frame rate. In color LED displays, one color frame (e.g. green) is supplied at the normal frame rate and the other colors (red, blue) are supplied at slower frame rates. In a further embodiment, frame rates of all colors are based on the image to be displayed.

Abstract: The display device (6) comprise s a display (2) and generating mean s (10, 8). The display (2) has a plurality of light emitting elements (3), and data lines (13) for providing pulse width modulation (PWM) signals to the light emitting elements (3). The generating means (10, 8) are coupled to the data lines (13) for generating, during time intervals (SF) of a frame period, at least a first non-zero emission level (L(V1;C1;I1)) of a light emitting element (3) during a first one of the time intervals (SF) and a second non-zero emission level (L(V2; C2; 12)) during a second one of the time intervals (SF).

Abstract: The invention relates to a display device comprising a plurality of light emitting elements (1), wherein at least one of the elements has an associated capacitor (C1). The display device comprises pre-charging means (7;8) for generating a pre-charge signal for charging the associated capacitor (C1) at least partly. The pre-charging means (7;8) are adapted for generating a pre-charge signal comprising at least a first pre-charge signal in a first pre-charge stage and a second pre-charge signal in a second pre-charge stage. The pre-charge signal preferably comprises a current pre-charge signal followed by a voltage pre-charge signal. The combined pre-charge signal has the advantage of fast, but accurate pre-charging.

Abstract: In a driver for a luminescent display feedback techniques, in particular techniques using a control amplifier (25), are used to reduce the power supply voltage.

Abstract: Matrix display device having row electrodes (4) and column electrodes (5), an intersection of a row and a column electrode defining a pixel cell (1) having a pixel cell capacitance (8), and drive circuits (2,3). Blind energy used for charging the pixel cell capacitances (8) when driving the pixel cells (1) is not dissipated but stored into a buffer capacitor (6) through an inductor (7) forming a series inductor-capacitor circuit and subsequently recovered by discharging the buffer capacitor (6) into the pixel cell capacitances (8) through a current source (13). Energy recovery is thus current driven, which allows to control the light reflected or emitted by the pixel cell (1) in a manner which is less dependent on temperature variations and/or ageing of the device.

Abstract: The present invention is directed towards a method of scanning lines in a display and towards a display control device for scanning lines in a way which is less trackable by the human eye as well as towards an electronic device including such a display control device. The control device includes a line driving unit (18,20) and a control unit (22), which control unit (22) varies the selection of lines to be scanned and controls the line driving unit (18,20) to scan the selected lines. Selection and scanning is varied in such a way that energy variations caused by the scanning of lines is less trackable by the human eye. In this way bright lines or flickering normally caused by scanning of lines is reduced.

Abstract: A display has a light-emitting layer, such as a light-emitting polymer or a small molecule compound layer, sandwiched between two electrodes structures including an anode structure having a plurality of subgroups of separated anode segments. Each mode segment in each anode subgroup is surrounded by anode segments that are not members of the same anode subgroup. Essentially each anode segment is a member of the anode subgroups. A signal selector assembly is connected to each anode segment, and is arranged to provide the anode segments of a single anode subgroup with image information signals, while holding the remaining anode segments at equal potentials.

Abstract: The invention relates to a display device, preferably an electroluminescent display device, comprising a matrix of pixels, each pixel being driven by a drive pulse (B), which is pulse width modulated. The device is characterized in that the width of the drive pulse is controlled by a gamma correction device, in which gamma correction information is supplied in the form of a separate pulse distribution-modulated signal (PDM). The invention also relates to a method of gamma correction in such a display device.

Abstract: This invention relates to a method of driving a display device (8) comprising a layer of organic electroluminescent material (4, 5), said layer being sandwiched between an anode (5) comprising a plurality of separated anode segments (5′) and a cathode (6), said method comprising the steps of dividing the anode segments (5′) into N subgroups (5a, 5b), each anode segment in each subgroup being surrounded by anode segments which are not members of the same subgroup, dividing an image signal IStot into corresponding N subgroups IS1, IS2, . . . ISN, so that the i:th subgroup comprises the information which is intended to be fed to the anode segments of the corresponding i:th anode segment subgroup, and, during a first time period t1, feeding a first subgroup (i=1) of said image signal IS1 to a corresponding first subgroup of first anode segments (5a), meanwhile holding all other anode segments at essentially equal potentials. This invention also relates to a device for use in the above method.

Abstract: To suppress dissipation in monochrome LED displays, each frame is supplied at half the frame rate. In color LED displays, one color frame (e.g. green) is supplied at the normal frame rate and the other colors (red, blue) are supplied at slower frame rates. In a further embodiment, frame rates of all colors are based on the image to be displayed.