Display for contrast enhancement

• US 4,832,458 A
• Filed: 10/05/1987
• Issued: 05/23/1989
• Est. Priority Date: 08/28/1984
• Status: Expired due to Term

• Current Assignee: Raychem Limited (TE Connectivity Limited)
• Original Assignee: Talig Corporation
• Inventors: Parker, Robert, Fergason, James L.
• Primary Examiner(s): Miller, Stanley D.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/105,557
• Time in Patent Office: 596 Days
• Field of Search: 350/334, 350/338, 350/337, 350/276 SL, 350/347 V, 350/331 R
• US Class Current: 349/56
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/13756 the liquid crystal selectively assuming a light-scattering state G02F1/1334, G02F1/13718 take precedence

Abstract

A display comprising optical means for presenting an absence of light over a controlled viewing angle and means for selectively scattering or transmitting light in response to a prescribed input to effect a display of information within said viewing angle.

Claims

1. A display for enhancing contrast and reducing glare, comprising:

a target means for absorbing light;

a concave reflector means for focusing light incident thereon including specular reflection onto said target means; and

means selectively operable for affecting light incident thereon by selectively scattering or transmitting light in response to a prescribed input, said selectively operable means including first and second major surfaces having a concave configuration substantially the same as said concave reflector means, and said target means located in front of and on a viewing side of said selectively operable means.

2. A display, comprising:

a film of nematic curvilinearly aligned phases liquid crystal material having first and second surfaces, and selectively operable for affecting light incident thereon by transmitting light in response to a prescribed input, and at least one of scattering and absorbing light in the absence of said prescribed input;

target means located in front of and on a viewing side of said film for absorbing light incident thereon; and

reflector means disposed on a non-viewing said of said film, said reflector means having a concave surface and said film disposed along said surface so that said first and second surfaces and said reflector means present a concave surface to light incident thereon from the viewing side thereof for focusing light transmitted by said film within a viewing angle onto said target means to enhance the contrast of and reduce glare from the display.

3. The display of claim 2 wherein said liquid crystal material is in a containment medium, said liquid crystal material having positive dielectric anisotropy and indices of refraction substantially matched to said containment medium to maximum optical transmission in the presence of

4. The display of claim 2 wherein said target means is located a approximately at the focal point of said reflector means.

5. The display of claim 2 wherein said reflector means has a radius or curvature R and said target means is located a distance of between 0.4R and 0.5R from said reflector means.

6. The display of claim 5 wherein said target means is located at a distance of 0.469R from said reflector means.

7. The display of claim 5 wherein said target means comprises vertically and horizontally extending light absorbing surfaces.

8. The display of claim 7 wherein the height of said vertically extending surface is approximately 0.0625R, the width of said horizontally and vertically extending surfaces are approximately equal to the width of the display plus R, and the length of said horizontally extending surface is at least 0.1R.

9. The display of claims 2 or 7 wherein said target means comprises a black absorber for absorbing at least substantially all of the light incident thereon.

10. The display of claim 7 wherein said target means comprises a colored absorber for absorbing only one or more specified wavelengths of light.

11. The display of claim 2 further including a substantially optically transparent support medium means for supporting and containing said film and said reflector means.

12. The display of claim 2 wherein said target means comprises a vertically extending light absorbing surface.