Thales

Thomson Licensing

Thomson-lcd

Thales Avionics Lcd S.a.

Interdigital Ce Patent Holdings

Thierry Kretz

Hugues Lebrun

Elisabeth Chuiton

Bruno Mourey

Gérard Voisin

Gérard Gomez

Bernard Meunier

Chantal Hordequin

In a liquid crystal or OLED active-matrix screen, the power supply voltages VGON and VGOFF of the display control circuit driving the control transistors of the pixels are optimized, as a function of a measurement of the operating temperature, to conserve the display qualities of the screen at high and low temperatures and reduce the power consumed on average to produce screens for applications in a severe environment, with transistors of standard size. Circuits are provided for supplying these analog voltages from numeric values supplied by a code associated with the temperature measurement, stored or computed by a programmable circuit. Provision is made to adapt these voltages as a function of a measurement of lighting level received by the transistors of the display control circuit. The optimization extends to the power supply and reference voltages necessary to the control of the pixels, notably to the gamma reference voltages.

Active-matrix display with power supply voltages controlled depending on the temperature

A display has a graphics processor that extracts from image memory just rows that have non-zero luminance information items for the colour under consideration. For each row to be written, the processor sends to a set of N sampling and conversion circuits, at high frequency, a pattern representing the rows to be written, in the form of a succession of N bits. The N samplers successively sample these bits during the succession, to sample and block the bit of rank i in the sampling circuit of rank i, and produce a pattern of N control voltages VGon or VGoff on the rows as a function of the pattern of the received succession, while the graphics processor applies to the columns the luminance data to be written. The operation is repeated solely for the rows that have a luminance information item to be written in the colour under consideration.

LCD display with row addressing using sampling and conversion, and display method

A video system including a sequential color liquid crystal display with a panel of pixels arranged in rows and columns, including a mechanism that controls unit brightness levels on each pixel in the panel called grey levels, each grey level corresponding to a video information received at the input. The grey level controlled on a pixel is achieved with an analog voltage that varies monotonously depending on the row associated with the pixel and/or a color to be displayed.

Sequential colour matrix liquid crystal display

An organic light-emitting display screen includes n&#xd7;m picture dots organized in a matrix with m rows and n columns. Each picture dot includes an organic diode and first and second driver circuits for the diode. Each of the first and second driver circuits includes a driving transistor connected between a reference voltage and one electrode of the diode, a switching transistor for switching a gate voltage onto a gate of the driving transistor, and a capacitor connected to the gate of the driving transistor. A circuit for addressing each of the n&#xd7;m picture dots, to control alternately and simultaneously a recovery phase on one driver circuit and a display phase on the other driver circuit of a picture dot, includes as row select lines, only m row select lines, one per row of picture dots, and/or as data lines, only n data lines, one per column of picture dots.

Organic electroluminescent display

A shift register, each stage thereof provided to drive a corresponding output line, includes an output transistor that drives the output line and an additional transistor of the same technology and of the same polarity as the output transistor. The additional transistor is connected in such a way as to be subject to bias conditions similar to the output transistor, such that the additional transistor's threshold voltage, identical at the start of life to that of the output transistor, drifts as quickly or more quickly as the threshold voltage of the output transistor. The additional transistor is used to adjust the precharging voltage of a gate of the output transistor to its conduction performance characteristics during the precharging and/or selection phase.

Field-effect transistor shift register

A process for protecting the external face of an electro-optical device, the external face comprising at least one optical film adhesively bonded to a transparent substrate and set back therefrom, comprises encapsulating the optical element between the substrate and a transparent cover that is substantially the same size as the substrate. The process comprises adhesive bonding of the cover, the adhesive bonding being achieved by depositing uncured adhesive in two steps, namely a first step that is used first to take up the step difference between the substrate and the optical element, and a second step that is used to adhesively bond the protective cover. Smaller respective thicknesses of adhesive shrink in each step and thus, in the end, the total shrinkage is limited and the quality of the product is improved.

Process for encapsulating an electro-optical device

A shift register driven by two complementary clock signals is integrated on an active-matrix substrate of a flat screen for controlling selection of rows of image points of the flat screen is disclosed. The shift register includes a control transistor driven by one of the clock signals, and connected between this clock signal and an output node connected to a corresponding row. The shift register also includes a capacitor connected between an internal node connected to the gate of the control transistor. The output node is discharged each time the flat screen starts.

Shift register for an active-matrix flat screen

An active matrix for an organic light-emitting diode display screen, including: pixels arranged in rows and in columns, each pixel including, a pixel electrode capable of accommodating an organic light-emitting diode on the surface, and first and second current drivers connected to said pixel electrode, wherein the first and second current drivers each include a current control transistor connected between a supply voltage Vdd and said pixel electrode and at least a first switching transistor that controls a gate of said current control transistor.

Active matrix of an organic light-emitting diode display screen

In an active matrix for a liquid crystal display, including a plurality of pixel electrodes in an active zone, each of which can be addressed using one selection line among N selection lines and one data line among M data lines, a storage capacitor is connected to each pixel electrode in the matrix, and a line stabilization capacitor is provided for each selection line in the matrix. A first electrode of the stabilization capacitor is connected to the selection line and a second electrode is connected to a reference voltage. Such a structure may find application to active matrix type liquid crystal displays, particularly with integrated drivers.

Active-matrix liquid crystal matrix display

In a method for addressing rows and columns in a liquid crystal display, each phase for addressing rows and columns in the display includes precharging pixels of the display before a row write, to apply a precharge voltage to all pixels. Depending on the selected black or white precharge level, the light box is either switched on permanently, or is switched on during each addressing phase immediately after the precharge or immediately after the row write. The display brightness is thus improved. The display may be of sequential color type.

Video system including a liquid crystal matrix display having a precharge phase with improved addressing method

An active matrix structure for display screen includes a storage capacitor bus disposed under each row of pixel electrodes, produced in a transparent conducting material, and disposed in the structure on a level separated from a level of the row selection lines and a level of the pixel electrodes by an insulation layer at least. The storage bus of a row is driven by a selection line of a previous row.

Active matrix structure for display screen and screen comprising one such matrix

The present invention relates to a process for displaying data on a matrix display consisting of N data lines and P selection lines at the intersections of which are situated the image points or pixels. The N data lines are grouped into {dot over (P)} blocks if N' lines where N={grave over (P)}&#xd7;N&#x2032;. Each block receives in parallel one of the P&#x2032; data signals which is demultiplexed on the N&#x2032; lines of the said block. The scanning of the N&#x2032; data lines of a block is carried out from 1 to N&#x2032; or from N&#x2032; to 1, alternately, according to the selection lines.

Method and apparatus for displaying data on a matrix display with an alternating order of scanning in adjacent groups of columns

The invention concerns a display screen with active matrix comprising first and second transparent substrates enclosing a crystal liquid material, at least one counter electrode, pixel electrodes in lines and in columns, data lines, perpendicular selection lines, control devices for connecting the lines to the pixel electrodes, the pixel electrodes being controlled such that the electrodes connected to a common selection line have the same polarity while, for two adjacent selection lines the polarity is reversed, the pixel electrodes being located in a first plane while the other elements are located in a second plane distanced from the first plane, and a transparent mass plane being located between the two planes. Moreover, the mass plane has a structure such that at least the part found between two pixel electrodes of same polarity is recessed. The invention is applicable to LCD.

Growing community of inventors

Saint Jean de Moirans, France

Thierry Kretz