TIR switched flat panel display

• US 8,272,770 B2
• Filed: 01/02/2009
• Issued: 09/25/2012
• Est. Priority Date: 01/02/2009
• Status: Expired due to Fees

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Rambus International Ltd (Rambus Inc.)
• Inventors: Richardson, Brian Edward
• Primary Examiner(s): Ton, Anabel
• Application Number:
  US12/319,171
• Publication Number:
  US 20100172138A1
• Time in Patent Office: 1,362 Days
• Field of Search: 362/277, 362/296.01, 362/307, 362/607, 362/616
• US Class Current: 362/605
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/3522 the optical element enabling or impairing total internal reflection using evanescent coupling G02B6/3536
• CPC Class Codes: G09F 9/30 in which the desired character or characters are formed by combining individual elements panels comprising a number of electrodes in a single cell controlling light arriving from an independent light source, e.g. electro-optical or magneto-optical cell, G02F1/00

Abstract

A flat panel display uses pixels that are turned on or off by the enabling or disabling total internal reflection, TIR, of a light guide. A reflective surface directs the switched light towards the viewer. An optional mask can be employed to provide extremely high contrast ratios in low and in high ambient lighting conditions. The elements that enable TIR can be enabled quickly because of their small size and weight, resulting in a very fast switching speed. The fast switching speed allows colors to be generated and displayed in a sequential manner.

Claims

1. A display device comprising:

a light source,

a light guide, and

a plurality of optical elements that allow selective extraction of light from said light guide;

wherein

light projected from said light source travels through said light guide by total internal reflection,

when light traveling through said light guide contacts one of said optical elements that is in an on position, light is extracted from said light guide via said optical element, the light being directed through said display device to a viewer, and

when light traveling through said light guide contacts one of said optical elements in an off position, the light continues to travel through said light guide by total internal reflection.

2. The display device of claim 1 wherein:

said optical elements are placed in said on position by physical contact of the optical element with said light guide, and

said optical elements are placed in said off position by maintaining a low index of refraction near a surface of said light guide, said surface of said light guide thereby maintaining total internal reflection.

3. The display device of claim 1 wherein:

said optical elements are placed in said on position by physical contact of said optical element with said light guide, a contact point of said at least one of said optical elements with said light guide creating a discontinuity of material that negates total internal reflection in said light guide.

4. The display device of claim 3 wherein:

said optical elements are moved between said on position and said off position by an electrostatic force.

5. The display device of claim 2 wherein:

physical contact of said optical elements with said light guide occurs on a side opposite an output side of said light guide.

6. The display device of claim 3 wherein:

physical contact of said optical elements with said light guide occurs on a side opposite an output side of said light guide.

7. The display device of claim 1 wherein:

said selective extraction of light occurs at an interface of said light guide and a controlling electronics panel.

8. The display device of claim 2 wherein:

said selective extraction of light occurs at an interface of said light guide and a controlling electronics panel.

9. The display device of claim 3 wherein:

said selective extraction of light occurs at an interface of said light guide and a controlling electronics panel.

10. The display device of claim 1 wherein:

said light source generates red, green, and blue light.

11. The display device of claim 2 wherein:

said light source generates red, green, and blue light.

12. The display device of claim 3 wherein:

said light source generates red, green, and blue light.

13. The display device of claim 1 wherein:

said light source generates red, green, blue, yellow, and cyan light.

14. The display device of claim 2 wherein:

said light source generates red, green, blue, yellow, and cyan light.

15. The display device of claim 3 wherein:

said light source generates red, green, blue, yellow, and cyan light.

16. The display device of claim 1 wherein:

said light source generates white light.

17. The display device of claim 2 wherein:

said light source generates white light.

18. The display device of claim 3 wherein:

said light source generates white light.

19. The display device of claim 1 wherein:

a mask plate made from light absorbing material is positioned between said light guide and an output of said display device, said mask plate comprising a plurality of apertures that allow light to pass through said mask plate, said mask plate thereby increasing a contrast ratio of said output of said display device.

20. The display device of claim 2 wherein:

a mask plate made from light absorbing material is positioned between said light guide and an output of said display device, said mask plate comprising a plurality of apertures that allow light to pass through said mask plate, said mask plate thereby increasing a contrast ratio of said output of said display device.

21. The display device of claim 3 wherein:

a mask plate made from light absorbing material is positioned between said light guide and an output of said display device, said mask plate comprising a plurality of apertures that allow light to pass through said mask plate, said mask plate thereby increasing a contrast ratio of said output of said display device.

22. The display device of claim 1 wherein:

at least one diffusing layer is positioned between said light guide and an output of said display device, said diffusing layer spreading said output of said display device to improve visibility of said output from angles displaced from normal to said output.

23. The display device of claim 2 wherein:

at least one diffusing layer is positioned between said light guide and an output of said display device, said diffusing layer spreading said output of said display device to improve visibility of said output from angles displaced from normal to said output.

24. The display device of claim 3 wherein:

at least one diffusing layer is positioned between said light guide and an output of said display device, said diffusing layer spreading said output of said display device to improve visibility of said output from angles displaced from normal to said output.