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1. (WO1998053366) METHOD FOR ENSURING THE OPERATIONAL SECURITY OF A LIQUID CRYSTAL DISPLAY
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1998/053366 International Application No.: PCT/FR1998/001025
Publication Date: 26.11.1998 International Filing Date: 20.05.1998
Chapter 2 Demand Filed: 08.12.1998
IPC:
G02F 1/1335 (2006.01) ,G06F 11/16 (2006.01) ,G09G 3/36 (2006.01)
G PHYSICS
02
OPTICS
F
DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
1
Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
01
for the control of the intensity, phase, polarisation or colour
13
based on liquid crystals, e.g. single liquid crystal display cells
133
Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
1333
Constructional arrangements
1335
Structural association of optical devices, e.g. polarisers, reflectors, with the cell
G PHYSICS
06
COMPUTING; CALCULATING; COUNTING
F
ELECTRIC DIGITAL DATA PROCESSING
11
Error detection; Error correction; Monitoring
07
Responding to the occurrence of a fault, e.g. fault tolerance
16
Error detection or correction of the data by redundancy in hardware
G PHYSICS
09
EDUCATING; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
G
ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
3
Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
20
for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix
34
by control of light from an independent source
36
using liquid crystals
Applicants:
SEXTANT AVIONIQUE [FR/FR]; Aérodrome de Villacoublay F-78240 Vélizy-Villacoublay, FR (AllExceptUS)
VOISIN, Gérard [FR/FR]; FR (UsOnly)
PERNIA, Olivier [FR/FR]; FR (UsOnly)
Inventors:
VOISIN, Gérard; FR
PERNIA, Olivier; FR
Agent:
THOMSON-CSF PROPRIETE INTELLECTUELLE; Dépt. Protection et Conseil 13, avenue du Président Salvador Allende F-94117 Arcueil Cedex, FR
Priority Data:
97/0633023.05.1997FR
Title (EN) METHOD FOR ENSURING THE OPERATIONAL SECURITY OF A LIQUID CRYSTAL DISPLAY
(FR) PROCEDE DE SECURISATION D'UN AFFICHEUR A CRISTAL LIQUIDE
Abstract:
(EN) The invention concerns a method for ensuring the operational security of liquid crystal displays to prevent their breakdown from being unnoticed. The method consists in using the polarising layers with perpendicular polarising axes and in controlling the columns (203) of the pixel matrix ensuring the display such that in case one of the two control cards (204, 205) of said columns breaks down, this does not cause one of the colours to disappear but a coloured comb to be superposed on the image. The method further consists in commanding a polarisation reversal from one writing to the next as soon as possible in the chain generating the column control signals. The method enables to obtain, in case of breakdown, the display of parasitic light signals which attract the observer's attention.
(FR) L'invention concerne les procédés qui permettent de sécuriser les afficheurs à cristal liquide pour empêcher une panne d'un tel afficheur de passer inaperçue. Elle consiste à utiliser des couches polarisantes dont les axes de polarisation sont perpendiculaires et à commander les colonnes (203) de la matrice de pixels permettant l'affichage de manière à ce que la panne de l'une des deux cartes de commande (204, 205) de ces colonnes n'entraîne pas la disparition complète de l'une des couleurs et entraîne la superposition à l'image d'un peigne coloré. On effectue en outre la commande d'inversion de polarisation d'une écriture à la suivante le plus tôt possible dans la chaîne d'élaboration des signaux de commande des colonnes. Elle permet d'obtenir en cas de panne l'affichage de signaux lumineux parasites qui attirent l'attention de l'observateur.
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Designated States: CA, JP, US
European Patent Office (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE)
Publication Language: French (FR)
Filing Language: French (FR)