The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 17, 2015
Filed:
Mar. 15, 2011
Terry Victor Clapp, Bishop's Stortford, GB;
William Alden Crossland, Harlow, GB;
Anthony Bernard Davey, Cambridge, GB;
Martin Grasmann, Midland, MI (US);
Jonathan Paul Hannington, Midland, MI (US);
Russell Keith King, Midland, MI (US);
Mikhael Pivnenko, Cambridge, GB;
Steven Robson, Vale of Glamorgan, GB;
Huan Xu, Cambridge, GB;
Terry Victor Clapp, Bishop's Stortford, GB;
William Alden Crossland, Harlow, GB;
Anthony Bernard Davey, Cambridge, GB;
Martin Grasmann, Midland, MI (US);
Jonathan Paul Hannington, Midland, MI (US);
Russell Keith King, Midland, MI (US);
Mikhael Pivnenko, Cambridge, GB;
Steven Robson, Vale of Glamorgan, GB;
Huan Xu, Cambridge, GB;
Dow Corning Corporation, Midland, MI (US);
Cambridge Enterprise Limited, Cambridge, GB;
Abstract
The present, invention relates to liquid crystal compositions having a smectic A structure for use in an optical device in which the composition is sandwiched between a pair of electrodes (-). In essence the composition includes a siloxane oligomer (component (a)) which may be seen to construct a layered SmA system of particular spacing and 'strength'. Within this structure a low molar mass nematic mesogen (component (c)) is provided that may be considered to be that of a 'plasticiser' which moderates the layer “strength”, while simultaneously providing tuneability to the properties of the composition, e.g. its refractive index or dielectric anisotropy. The addition of a side chain liquid crystal polysiloxane (component (d)) allows such systems to be further moderated since they can be considered as binding together the la>¾rs, both within a given layer and between layers. An ionic dopant (component (b)) is also included in the composition that migrates through the composition when low frequency electric fields are applied to the composition by the electrodes, thereby disrupting the order to the composition. Order in the composition can be restored by applying a higher frequency field that does not allow the dopant time to migrate significantly. Chromophores may also be included in the formulation.