Optical device

• US 6,549,253 B1
• Filed: 11/08/1999
• Issued: 04/15/2003
• Est. Priority Date: 11/09/1998
• Status: Expired due to Fees

• Current Assignee: The Governors of the University of Alberta (University of Alberta)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Brett, Michael J., Sit, Jeremy C.-H., Robbie, Kevin J., Broer, Dirk J.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGUYEN, DUNG T
• Application Number:
  US09/436,194
• Time in Patent Office: 1,254 Days
• Field of Search: 349/84, 349/172, 349/171, 349/175, 349/184-186
• US Class Current: 349/84
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133734 by obliquely evaporated films, e.g. Si or SiO2 films

Abstract

The invention relates to an optical device comprising two substantially parallel substrates with electrode layers on their facing sides for switching an optically active layer which is present between said substrates. Furthermore the present invention relates to a hybrid layer for use in such an optical device. Switching of the layers is enhanced by introducing optically anisotropic material in a porous structure.

Claims

1. Hybrid layer for use in an optical device, said layer containing an optically anisotropic liquid crystal material as well as a porous columnar structure, wherein the porous columnar structure comprises a helical structure.

2. Optical device comprising two substantially parallel substrates with electrode layer on their facing sides for switching an optically active layer which is present between said substrates, characterized in that the optically active layer is formed as a hybrid layer containing an optically anisotropic liquid crystal material as well as a porous columnar structure, wherein the porous columnar structure comprises a helical structure.

3. Optical device as claimed in claim 2, where by the presence of said structure results in a lowering of the switching voltage of the optical device.