Image projector with maximized light efficiency

The invention relates to an image projector in which the lighting of an LCD matrix screen (5) is carried out with the aid of two polarised beams (FP1, FP2) originating from the same light beam (FS) not having any particular direction of polarisation. The two polarised beams are obtained with a polar...

Ausführliche Beschreibung

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Bibliographische Detailangaben
Hauptverfasser:	LOISEAUX, BRIGITTE, NICOLAS, CHRISTOPHE, HUIGNARD, JEAN-PIERRE
Format:	Patent
Sprache:	eng ; fre ; ger
Schlagworte:	ACCESSORIES THEREFOR APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM CINEMATOGRAPHY DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING ELECTRIC COMMUNICATION TECHNIQUE ELECTRICITY ELECTROGRAPHY FREQUENCY-CHANGING HOLOGRAPHY NON-LINEAR OPTICS OPTICAL ANALOGUE/DIGITAL CONVERTERS OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS OPTICAL LOGIC ELEMENTS OPTICS PHOTOGRAPHY PHYSICS PICTORIAL COMMUNICATION, e.g. TELEVISION TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF
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Beschreibung
Zusammenfassung:	The invention relates to an image projector in which the lighting of an LCD matrix screen (5) is carried out with the aid of two polarised beams (FP1, FP2) originating from the same light beam (FS) not having any particular direction of polarisation. The two polarised beams are obtained with a polarisation splitter (SP) from which these two polarised beams emerge with a square cross-section. According to the invention, on the one hand, each polarised beam (FP1, FP2) passes through at least two juxtaposed convergent lenses (L1, L2) which convert it into two sub-beams (SF1, SF2) which project their lighting spot onto the matrix screen (5), and on the other hand, each convergent lens has a surface whose shape is homothetic with that of the matrix screen. The luminous efficiency is thereby improved by adapting the shape of the cross-section of the non-polarised light beam (FS) to that of the matrix screen (5).