Thomson Licensing

Thomson-csf

Philippe Le Roy

Christophe Prat

Sylvain Thiebaud

Jean-Paul Dagois

Arnaud Trochet

David Vaufrey

Pierrick Martin

Valter Drazic

Carlos Correa

Sébastien Weitbruch

Gunther Karl Haas

Heinrich Schemmann

Pascal Bourdon

Christophe Fery

Sebastien Weitbruch

Laurent Blondé

Nadine Patry

Dominique Gagnot

Denis Mischler

Dennis Cota

Christophe Venaille

Christopher Prat

Fabien Ammardji

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.

Driver for controlling a light emitting element, in particular an organic light emitting diode

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.

Method of driving a display panel with depolarization

The invention relates to an active-matrix display device which comprises: The power supply means for the emitters are capable of supplying the emitters during the programming step.

Device for displaying images on an active matrix

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.

Method and device for displaying an image on an organic light emitting display where a frame is divided into two groups of subframes

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.

Method for detecting a flexion exerted on a flexible screen and device equipped with such a screen for implementing the method

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.

Method for controlling a display panel by capacitive coupling

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.

Recording level gauge type organic light emitting diode

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.

Image display screen

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.

Method for processing a video sequence and apparatus implementing said method

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. According to the invention, the pixels of the switching array and the illuminating lines of the backlighting unit are substantially aligned in order that a given pixel allows the forward transmission of only the corresponding base color to be controlled and that a cylindrical lens is disposed along each illuminating line on the backlighting unit in order to form a light beam with substantially parallel edges directed towards the front and through the switching array, the lens having a length substantially equal to the length of the illuminating line.

Colour display device with backlighting unit using organic light-emitting diodes and method of implementation

The invention relates to an image display screen including: 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.

Image display screen and method for controlling said screen

Panel comprising display drivers which, each&#x2033;', 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.

Display panel and control method using transient capacitive coupling

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 (I)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 (I) to said circuit node; a comparator having inputs connected to said circuit node and to a reference terminal which is constantly held at said specific voltage level and an output connected to a control input of said second current modulator, whereby the second current (I) from said second current modulator is controlled so as to yield said specific voltage level at the circuit node.

Video display device and operating method therefore

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.

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Betton, France

Philippe Le Roy