Abstract: A device for influencing light has a polarizer, a ferroelectric or electroclinic response type liquid crystal halfwave plate whose liquid crystals are in the smectic phase with bookshelf geometry and have molecular axes which are rotatable around a first direction corresponding to the direction of incoming light in response to an electric field applied across the electrodes on either side of the halfwave plate, a quarter wave retarder plate, and a mirror. The polarizer, plates and mirror are arranged such that incoming light is passed from the polarizer through the liquid crystal plate and the retarder plate, and is reflected by the mirror in a second direction opposite to the first direction back through the retarder and the liquid crystal plate so as to provide a reflected polarized light plane to the polarizer.
Type:
Grant
Filed:
May 16, 1997
Date of Patent:
October 10, 2000
Assignee:
S.T. Lagerwall S.A.R.L.
Inventors:
Gunnar Andersson, Ingolf Dahl, Lachezar Komitov, Sven Torbjorn Lagerwall, Kent Skarp, Bengt Stebler
Abstract: A device for influencing light has a polarizer, a ferroelectric or electroclinic response type liquid crystal halfwave plate whose liquid crystals are in the smectic phase with bookshelf geometry and have molecular axes which are rotatable around a first direction corresponding to the direction of incoming light in response to an electric field applied across the electrodes on either side of the halfwave plate, a quarter wave retarder plate, and a mirror. The polarizer, plates and mirror are arranged such that incoming light is passed from the polarizer through the liquid crystal plate and the retarder plate, and is reflected by the mirror in a second direction opposite to the first direction back through the retarder and the liquid crystal plate so as to provide a reflected polarized light plane to the polarizer.
Type:
Grant
Filed:
June 7, 1995
Date of Patent:
December 8, 1998
Assignee:
S.T. Lagerwall S.A.R.L.
Inventors:
Gunnar Andersson, Ingolf Dahl, Lachezar Komitov, Sven Torbjorn Lagerwall, Kent Skarp, Bengt Stebler
Abstract: An electro-optical device including a chiral nematic liquid crystal disposed between flat plates treated to weakly enforce molecular orientation along one preferred direction parallel to the plates. The plates are spaced by a distance small compared to the pitch of the helix typical in a bulk of the material, or the helix compensated by additives to ensure the equivalent situation. By an externally applied electric field the liquid crystal molecular orientation is rotated in a plane parallel to the plates away from the preferred orientation an angle the sign and size of which depends on the sign and magnitude of the field. The optical axis of the liquid crystal, oriented along the molecular orientation, is thus controlled by the external electric field in such a way as to make a linear light valve or other electro-optical device.
Type:
Grant
Filed:
May 18, 1992
Date of Patent:
September 21, 1993
Assignee:
S. T. Lagerwall S.A.R.L.
Inventors:
Gunnar Andersson, Lachezar Komitov, Sven T. Lagerwall, Bengt Stebler, Kurt Flatischler