Enhanced off-axis viewing performance of liquid crystal display employing a fiberoptic faceplate having an opaquely masked front surface on the front face

• US 5,959,711 A
• Filed: 12/12/1996
• Issued: 09/28/1999
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Silverstein, Louis D., Crawford, Greg P., Fiske, Thomas G.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Parker, Kenneth
• Application Number:
  US08/761,992
• Time in Patent Office: 1,020 Days
• Field of Search: 349/64, 349/104, 349/110, 349/137, 349/159
• US Class Current: 349/159
• CPC Class Codes: G02B 6/08 with fibre bundle in form of plate
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis

Abstract

A transmissive, backlit color twisted-nematic or super-twisted-nematic liquid crystal display employing a front fiber-optic faceplate or optical equivalent as a front retaining element of a liquid crystal cell that increases viewing angle between the display and a viewer while minimizing or eliminating undesirable variations in luminance, contrast ratio and chromaticity is described. In particular, the fiber-optic faceplate or optical equivalent includes cylindrical optical features and interstitial cladding material. The interstitial cladding material may include an opaque mask blocking layer to prevent the interstitial apertures from diffracting off-axis light into an observer'"'"'s viewing cone. Further, the interstitial cladding material may be opaque.

Claims

1. A direct-view, rear-illuminated liquid crystal display device, comprising in sequential order:

a backlight source;

a rear diffuser layer;

a rear linear polarizer; and

a liquid crystal cell including a rear glass layer with addressing elements and pixel ITO electrodes, a liquid crystal layer and a front fiber-optic faceplate as a front containing element substantially adjacent to said liquid crystal layer, said front fiber-optic faceplate including optical fibers and cladding material, said front fiber-optic faceplate having opaque cladding apertures on the front face, wherein only a front surface of the fiber cladding material is opaquely masked.

2. The direct-view liquid crystal display device of claim 1, further comprising a front polarizer adjacent to the front surface of said front fiber-optic faceplate.

3. The direct-view liquid crystal display device of claim 1, further comprising a front polarizer between the liquid crystal layer and the rear surface of the front fiber-optic faceplate.

4. The direct-view liquid crystal display device of claim 2, further comprising a first brightness-enhancing film located between the rear diffuser layer and the rear linear polarizer.

5. The direct-view liquid crystal display device of claim 4, further comprising a second brightness-enhancing film located between the first brightness-enhancing film and the rear linear polarizer.

6. The direct-view liquid crystal display device of claim 5, wherein said liquid crystal layer is aligned to produce a highly anisotropic light distribution possessing extremely high contrast around a narrow meridian of the display viewing volume.

7. The direct-view liquid crystal display device of claim 2, further comprising a negative retarder located between the liquid crystal layer and the front polarizer.

8. The direct-view liquid crystal display device of claim 1, wherein said liquid crystal layer is aligned to produce a highly anisotropic light distribution possessing extremely high contrast around a narrow meridian of the display viewing volume.

9. The direct-view liquid crystal display device of claim 1, wherein said liquid crystal layer is composed of twisted nematic material.

10. The direct-view liquid crystal display device of claim 1, wherein said liquid crystal layer is composed of super-twisted nematic material.

11. The direct-view liquid crystal display device of claim 1, wherein the opaque cladding apertures are formed by applying a light-blocking, anti-reflective coating over the front surface of the front fiber-optic faceplate and patterning away the light-blocking, anti-reflective coating from the core apertures.