High efficiency, color coding light pipe methods for display applications, utilizing chiral liquid crystal materials

• US 6,204,899 B1
• Filed: 08/20/1998
• Issued: 03/20/2001
• Est. Priority Date: 04/16/1996
• Status: Expired due to Fees

• Current Assignee: Dennis R. Hall
• Original Assignee: Dennis R. Hall
• Inventors: Hall, Dennis R.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Ngo, Julie
• Application Number:
  US09/137,880
• Time in Patent Office: 943 Days
• Field of Search: 349/65, 349/97, 349/115, 349/98, 349/106, 349/176, 359/465, 396/326
• US Class Current: 349/65
• CPC Class Codes: G02F 1/133543 Cholesteric polarisers
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence

Abstract

The invention teaches methods whereby the lighting efficiency of many lighted displays, including liquid Crystal Displays (LCDs) are increased by an order of magnitude through the use of chiral nematic liquid crystal materials incorporated into the light pipes of the displays. The light pipe technology also enables a practical embodiment of the stereoscopic display of Venolia. These methods are also applied to the fabrication of lighted signs for advertising and status indicators in hostile environments. The technology of the light pipes is also applied to the creation of a novel art medium.

Claims

1. An illuminated display comprising:

a first non-birefringent transparent medium having a first main surface and a port allowing injection of light into said medium,

a light source for injecting light of a first specific color and polarization orientation into the medium through the port, and

a first chiral liquid crystal (CLC) filter/mirror structure on said main surface of the medium, said first CLC structure including a first CLC filter/mirror layer reflecting light of said first specific color and polarization orientation, said first CLC filter/mirror layer having at least one aperture providing a first display element, whereby light of said fist specific color and polarization orientation when injected into said non-birefringent transparent medium is passed through said first display element to a viewer.

2. An illuminated display according to claim 1, wherein the CLC filter/mirror structure includes a second CLC filter/mirror layer which is superimposed on said first CLC filter/mirror layer and reflects light of a second specific color or polarization orientation, said second CLC filter/mirror layer having at least one aperture providing a second display element, whereby light of said second specific color or polarization orientation when injected into said non-birefringent transparent medium is passed through said second display element to a viewer.

3. An illuminated display according to claim 1, wherein the non-birefringent transparent medium has a second main surface and the illuminated display further comprises a second CLC filter/mirror structure on said second main surface of the medium, said second CLC structure including a second CLC filter/mirror layer reflecting light of a specific color and polarization orientation, said second CLC filter/mirror layer having at least one aperture providing a second display element, whereby light of said specific color and polarization orientation reflected by the second CLC filter/mirror layer when injected into said non-birefringent transparent medium is passed through said second display element to a viewer.