France Telecom Etablissement Autonome De Droit Public

France Telecom

L'etat Francais Represente Par Le Ministre Des Postes, Des

Sagem

Societe D'applications Generales D'electricite Et De Mecanique Sagem

Centre National D'etudes Des Telecommunications

C/net, Inc.

Bruno Vinouze

Joseph Richard

Hugues Lebrun

Jean-Yves Moreno

Francois Lacroix

Francois Morin

Philippe Gravey

Dominique Bosc

Yannick Chouan

Nicole Wolffer

Martine Guilbert

Roger Lever

Madeleine Bonnel

Rene Baumes

The invention concerns a switch for optical beams comprising a series of optical input channels () and a series of optical output channels (), two liquid crystal cells respectively adapted to deflect an optical beam coming out of an input channel () or arriving onto an output channel (), said two cells comprising each a series of electrodes adapted to orient liquid crystals when one such electrode is subjected to a supply voltage said electrodes being distributed in zones (), each zone corresponding to a single input channel () or a single output channel (), the switch further comprising means for supplying the electrodes with selected voltages. The invention is characterised in that it comprises a series of separate electronic circuits, each being connected to at least a different zone () of a given cell, said circuits being each capable of transforming a respective control signal indicating a channel to be coupled to the channel of said zone () into a series of supply voltages for the electrodes of the zone ().

Liquid crystal optical switch with burnt-in control

A liquid crystal display screen which includes a first transparent plate covered with an electrode array and a second transparent plate covered with a counter-electrode. A liquid crystal film is inserted between the first and second plates. Further, either of the first or second transparent plates is covered with a material coating which diffuses ambient light with a brightness which exceeds a brightness of the liquid crystal film in the absence of excitation. This coating may take the form of a metal, a white mineral pigment or a polymer film which contains surface microcracks. Such a liquid crystal display screen as in the present invention may find particular applications to terminals, computers, pocket calculators, etc.

Diffusing matrix liquid crystal display screen

A method for forming a display cell with counter-electrode contact pick-ups. Contact blocks are separated from counter-electrode contacts by means of a passivation film. An electrical connection between the counter-electrode and the contacts is obtained by calcining the glue of the blocks to render it conductive by the use of a laser beam. The passivation film and counter-electrode contact are also perforated by using the laser beam.

Method for forming a display cell with counter-electrode contact pick-up

A method for embodying a display cell with a counter-electrode contact pickup. Contact blocks 12 are separated from counter-electrode contacts 20 by passivation film 22. The electrodes linked between the counter-electrode and the contacts 20 are obtained by calcining the glue of the blocks so as to render them conductive by using a laser beam 30. In addition, the passivation film 22 is perforated by using the laser beam 30. This method finds particular application in the embodiment of liquid crystal display screens.

Method for embodying a display cell with counter-electrode contact

The machine includes a frame (11) and a film (12) for one of two substrates (1, 2) to be pressed onto the other under a plate (4). It is then possible to polymerize by points a glue joint (3) so as to assemble the two substrates. Accurate displacement means (7, 8, 9, 10) and observation means (13, 14, 15) are also provided. Application for the embodiment of liquid crystal cells.

Machine for assembling liquid crystal cells

This color display structure for color display purposes has a first and second spaced, transparent substrates, between which is interposed a liquid crystal film (6), the first substrate (2) essentially supporting color filters (124) resistant to high temperatures and separated by black matrixes (126), a first transparent, passivating layer (128) deposited on the entire surface occupied by the filters and the black matrixes, thin film transistors (8, 9), formed on the first passivating layer facing the black matrixes so as to be protected from the ambient light, first transparent capacitor plates (10) formed on the first passivating layer facing the color filters and connected to the transistors, electrode rows (14) and columns (12) for controlling these transistors and a second transparent passivating layer (20) covering the transistors, the first plates, the rows and the columns, the second substrate (4) essentially having the second transparent capacitor plate.

Active matrix, high definition, liquid crystal display structure

Method for producing a display screen with a matrix of transistors provided with an optical mask. This method consists of depositing on a substrate (100) a layer of black polyimide (102) absorbing the visible light and followed by a layer of photosensitive resin, of insolating the resin through a mask masking the channels of the transistors to be embodied, of eliminating the zones insolated with the resin and the sub-adjacent zones of the polyimide, of depositing an ITO layer (106) on the unit, of eliminating the rest of the resin and the ITO surmounting said resin so as to form the drains/sources of the transistors, of successively depositing a layer of hydrogenated amorphous silicon (110), a layer of silicon nitride (112) and a layer of aluminium (114), then of photoengraving the stack of these layers so as to form the gate of the transistors, and finally to render passive the unit with a layer of silicon (116).

Method to produce a display screen with a matrix of transistors provided

Method for producing a display screen with a matrix of transistors provided with an optical mask. This method consists of depositing on a substrate (100) a layer of black polyimide (102) absorbing the visible light and followed by a layer of photosensitive resin, of insolating the resin through a mask masking the channels of the transistors to be embodied, of eliminating the zones insolated with the resin and the sub-adjacent zones of the polyimide, of depositing an ITO layer (106) on the unit, of eliminating the rest of the resin and the ITO surmounting said resin so as to form the drains/sources of the transistors, of successively depositing a layer of hydrogenated amorphous silicon (110), a layer of silicon nitride (112) and a layer of aluminium (114), then of photoengraving the stack of these layers so as to form the grid of the transistors, and finally to render passive the unit with a layer of silicon (116).

Dual addressing transistor active matrix display screen

An active matrix display screen which does not include a spurious transistor. The screen includes a matrix of pixels with addressing columns and rows. The addressing rows consist of a stack of semiconductive material, insulating material and conductive material. Where the addressing rows cover conductive segments, a matrix of transistors is formed.

Growing community of inventors

Port-Blanc, France

Bruno Vinouze