Display device comprising a light guide

• US 7,463,227 B2
• Filed: 07/29/2003
• Issued: 12/09/2008
• Est. Priority Date: 11/29/1997
• Status: Expired due to Fees

• Current Assignee: Rambus Delaware
• Original Assignee: Uni-Pixel Displays Incorporated (Uni-Pixel Incorporated)
• Inventors: Van Gorkom, Gerardus G. P.
• Primary Examiner(s): Liang; Regina
• Application Number:
  US10/628,942
• Publication Number:
  US 20040061665A1
• Time in Patent Office: 1,960 Days
• Field of Search: 345 30- 32, 345/36, 345/51, 345/85, 345/87, 345/102, 345/108
• US Class Current: 345/85
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 6/0033 Means for improving the coupling-out of light from the light guide
• 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 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/3522 the optical element enabling or impairing total internal reflection using evanescent coupling G02B6/3536
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/3473 based on light coupled out of a light guide, e.g. due to scattering, by contracting the light guide with external means

Abstract

A display device comprises a light guide and a movable element. By locally exerting a force on the movable element by means of selection means, optical contact between the movable element and the light guide can be brought about. Light emanates from the display device at the locations where optical contact takes place. Measures are taken to employ the force exerted by the selection means as efficiently as possible. This can be achieved by making the force act at the location where the optical contact takes place and/or by reducing other adhesive forces (caused, inter alia, by differences in pressure, static charging, surface stresses, van der Waals'"'"' forces and/or chemical forces).

Claims

1. A display device comprising:

a light guide;

a movable element; and

selection means to locally bring the movable element into contact with the light guide,

wherein the selection means comprise transparent electrodes and, in operation, the movable element, provided that it is in contact with the light guide, contacts the light guide at the location of an electrode, thus causing light to be emitted through the transparent electrode.

2. The display device of claim 1, wherein the movable element is electrically conducting and at a fixed potential.

3. The display device of claim 1, wherein there is no liquid between the movable element and the light guide.

4. The display device of claim 1, wherein the movable element is situated in an evacuated space below 0.1 atmosphere.

5. The display device of claim 4, wherein the evacuated space is below 10 Torr.

6. The display device of claim 1, wherein the movable element is arranged between the light guide and a further element, and the selection means comprise means for locally generating a force causing the movable element to move towards the light guide as well as a force causing the movable element to move towards the further element.

7. The display device of claim 1, wherein a surface of the movable element facing the light guide is a same material as a surface of the light guide facing the movable element.

8. A display device comprising:

a light guide;

a movable element; and

selection means to locally bring the movable element into contact with the light guide;

wherein the movable element is situated in an evacuated space below 0.1 atmosphere, and

wherein the selection means includes transparent electrodes and, in operation, the movable element, provided that it is in contact with the light guide, contacts the light guide at the location of an electrode, thus causing light to be emitted through the transparent electrode.

9. A display device comprising:

a light guide;

a movable element; and

selection means to locally bring the movable element into contact with the light guide,

wherein at least one of the movable element and the light guide is provided with an anti-adhesion layer on the side at which the contact is made between the movable element and the light guide, and

wherein the selection means comprises electrodes, and at least one of the first and second electrodes is substantially transparent.

10. The display device of claim 9, wherein the movable element is electrically conducting and at a fixed potential.

11. The display device of claim 10, wherein the movable element is situated in an evacuated space that is below 0.1 atmosphere.