Abstract: The present invention relates to a circuit for controlling a light emitting element, in particular an organic light emitting diode. The circuit comprises a capacitor connectable with the light emitting element, charging means for charging the capacitor and a switching means. The switching means is adapted to alternately disconnect the capacitor from the light emitting element and connect the capacitor to the light emitting element. The capacitor is alternately charged and discharged. A charging current or a discharge current from the capacitor drives the current of the light emitting element. Said charging means comprises at least one charging transistor for charging the capacitor.

Abstract: The method comprises, in addition to emission periods, depolarization periods during which a predetermined depolarization voltage, which exhibits a polarity opposite to the polarity opposite to the voltage applied during the emission periods, is applied and sustained at the control terminal of said driver circuits of the panel, and a reference depolarization voltage, which is different from the reference emission voltage, is applied to the reference electrodes to which reference terminals of the driver circuits are linked. This method makes it possible to use conventional and inexpensive column control means.

Abstract: The invention relates to an active-matrix display device which comprises: an array of light emitters, each emitter being supplied by power supply means; a current modulator having a trip-threshold voltage, said modulator being able to be addressed by applying a data setpoint to one of its terminals and a drain current being able to flow through said modulator in order to control said emitter; and trip-threshold voltage compensation means comprising a comparator for comparing the value of the drain current with the value of the data setpoint during a programming step. The power supply means for the emitters are capable of supplying the emitters during the programming step.

Abstract: A method and a device for displaying an image on an Organic Light Emitting Display where a frame is divided into two groups of subframes are provided for flicker-free and very high level motion rendition. The first group of sub-frames and the at least second group of sub-frames comprise corresponding sub-frames and constitute each a complete image in a video frame and corresponding sub-frames of two groups of sub-frames have similar but not automatically the same duration. The data signal of a cell comprises plural independent elementary data signals wherein each of the elementary data signals is applied to the cell during a sub-frame and the gray scale level displayed by the cell during the respective group of sub-frames depends on the amplitude of the elementary data signals and the duration of the sub-frames.

Abstract: Present day, technology allows flexible screens to be produced, particularly the OLED screen technology. The invention relates to a device equipped with a flexible screen emitting light. Part of the light rays emitted by the optical cells is imprisoned between the substrate layers and reflecting from one layer to the other exit at the side of the screen. Photoelectric detectors are arranged on the side of the screen in order to capture the incident light. Depending on the position of the cells emitting the light and the values supplied by the detectors, the central processing unit determines the areas of flexion applied to the screen. Hence, it is possible to introduce commands by exerting flexions on certain areas of the screen. The invention also relates to a device having a flexible screen and flexion sensors capable of executing the method for the introduction of commands.

Abstract: The method comprises, in addition to emission periods, depolarization periods during which a predetermined depolarization voltage, which exhibits a polarity opposite to the polarity opposite to the voltage applied during the emission periods, is applied and sustained at the control terminal of said driver circuits of the panel, and a reference depolarization voltage, which is different from the reference emission voltage, is applied to the reference electrodes to which reference terminals of the driver circuits are linked. This method makes it possible to use conventional and inexpensive column control means.

Abstract: A method comprising emission periods during which a predetermined emission voltage, which presents a first polarity, is applied and sustained at the control terminal of at least one driver of said panel, and depolarization periods during which a predetermined depolarization voltage, which presents a second polarity, opposite to the first polarity, is applied and sustained at the control terminal of at least one driver of said panel, the address signals of the circuits of said panel being transmitted by capacitive coupling of the address electrodes to the control terminals of these circuits. The invention makes it possible to use conventional and inexpensive means of controlling the address electrodes.

Abstract: Diode for which one of the conducting layers presents a suitable surface resistance so that when a power supply voltage is applied between a connection element and this conducting layer and the other conducting layer, a potential distribution is generated at the surface of this resisting conducting layer which is able to cause light to be emitted by a portion of the surface of the organic light emitting layer which is proportional to this power supply voltage. This diode is advantageously used to visualize the signal value.

Abstract: Image display screen suitable for displaying image frames, at a given screen scanning frequency, comprising, light emitters, circuits for addressing the emitters each comprising, a current modulator able to supply the said emitter with current during the screen display mode, a charge capacitance able to store at each image frame a potential applied to the gate electrode of the current modulator, the potential being representative of a voltage for addressing an image datum during a screen display mode. The screen comprises a control system able to apply a bias voltage to the gate electrode of the current modulator and to the said charge capacitance, during a screen standby mode of a duration greater than the duration of an image frame, the said bias voltage having a bias inverse to the bias of the potential applied to the said charge capacitance during the screen display mode.

Abstract: The present invention is in the field of Content protection, most particularly in cinema venues where camcorder acquisition followed by immediate illegal distribution creates important revenue losses for content owners. It is known that anti-camcorder systems using a color modulation can be circumvented by using low shutter speed in the camcorder. Today, the shutter speed is determined automatically by the camcorder as a function of the filmed video source. In automatic configurations, shutter speed self-adapts to either motion, or flicker detection, both of which taking into account brightness variations only. The proposed invention proposes a dual color/brightness modulation to defeat automatic shutter speed adjustment. For example, a color modulation at 50/60 Hz is carried out and a brightness modulation at a higher frequency 100/120 Hz is added to force the camcorder to work at a high shutter speed.

Abstract: The invention relates to a color display device with backlighting unit using organic light-emitting diodes and to a method of implementation. The color display device comprises, from rear to front towards an observer, a multicolor backlighting unit using organic light-emitting diodes and an electro-optical array for switching of the backlighting by pixels, the backlighting unit being a surface comprising a periodic pattern of a group of at least three adjacent illuminating lines of different base colors that are parallel to each other.

Abstract: The invention relates to an image display screen including: light emitters arranged as rows of light emitters and columns of light emitters, control means to control the emissions of the light emitters, including: a plurality of modulation transistors, each associated with one light emitter of the array, the said modulation transistors being positioned next to each other, along a guiding line, a plurality of compensating transistors intended to compensate for the threshold trigger voltage of the modulation transistors. A single compensating transistor is connected to all the modulation transistors of a column and is intended to compensate for the threshold trigger voltages of all the said modulation transistors of this column. This compensating transistor is formed in the extension of the said modulation transistors of a column along the same guiding line. The invention also relates to a method for driving this screen.

Abstract: Panel comprising display drivers which, each 1??, comprise a select switch and a clamping switch which are controlled by the same select electrode, and a coupling capacitor for transiently coupling the control terminal of this circuit C to an address electrode. A control method comprising emission periods and depolarization periods, where all the address signals have the same polarity. The invention makes it possible in particular to use conventional and inexpensive means of controlling the address electrodes.

Abstract: A video display device comprises a plurality of light emitting elements arranged in a matrix having rows and columns; a plurality of first current modulators each of which is associated to one of said light emitting elements for drawing a feed current of programmable intensity for the associated light emitting element from a circuit node associated to each of said columns; a current generator controlled by video data representative of desired luminosities of said light emitting elements for supplying a first current (IDATA)to said circuit node, the intensity of which is representative of a desired luminosity of at least one of said light emitting elements; the circuit node having a specific voltage level when the intensity supplied by said current generator is drawn from the current node by the first current modulator associated to said at least one light emitting element; a second current modulator for supplying a second current (I10) to said circuit node; a comparator having inputs connected to said circuit

Abstract: The invention relates to a light transmitter comprising two electrodes facing each other, and at least one light-emitting organic layer with two ends. The thickness of the organic layer varies continuously between the two ends. The invention also relates to a display device comprising such a transmitter.

Abstract: The invention relates to an image display device with active matrix comprising a number of light emitters forming a network divided into rows and columns; a current modulator for each emitter; and at least one inverse bias voltage generator. This device is characterized in that it also comprises: an inverse bias switch for each emitter, said inverse bias switch being connected, on the one hand, to each modulator and, on the other hand, to the or each inverse bias voltage generator; and control electrodes able to drive all the inverse bias switches of a row of emitters. The invention also relates to a method of driving this device.

Abstract: The present invention relates to a method and an apparatus for controlling the power level and/or the contrast in a display device having a plurality of luminous elements corresponding to the colour components of the pixels of a picture, wherein the luminance generated by each of said luminous element is based on the intensity of the signal supplied to the luminous element and the power level and/or contrast for each picture is controlled by adjusting the intensity of the signal to be supplied to each luminous element. The invention is applicable to organic light emitting displays (OLED). According to the invention, the intensity of the signal to be supplied to each luminous element is based on reference signals and the adjustment of the signal intensity is made by adjusting the level of the reference signals.

Abstract: The invention relates to a backlight device with light emissive diodes not requiring the supply of a large current. According to the invention, each light emissive diode of the backlight device is combined with a voltage converter capable of storing energy during part of the operating cycle and then discharging this energy into the light emissive diode during another part of the cycle.

Abstract: The invention relates to a light transmitter comprising two electrodes facing each other, and at least one light-emitting organic layer with two ends. The thickness of the organic layer varies continuously between the two ends. The invention also relates to a display device comprising such a transmitter.

Abstract: Diode for which one of the conducting layers presents a suitable surface resistance so that when a power supply voltage is applied between a connection element and this conducting layer and the other conducting layer, a potential distribution is generated at the surface of this resisting conducting layer which is able to cause light to be emitted by a portion of the surface of the organic light emitting layer which is proportional to this power supply voltage. This diode is advantageously used to visualise the signal value.