← Back to Patent Explorer
US5288591A Expired / Lapsed US ⏱️ 0.0 years remaining

LCD display with microtextured back reflector and method for making same

Assignee: Nokia Bell Labs
•
Filing: 1993-03-29
•
Granted: 1994-02-22
•
Expires: 2013-03-29
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Applicant has discovered a method for microembossing reflector surfaces with controlled reflecting patterns too small to be resolved by the unaided eye but capable of providing controlled reflection characteristics superior to uncontrolled random deformation. The result is a microtextured reflector of having dispersion characteristics of enhanced uniformity and a display device which can be read over an enhanced range of viewing angles. Specifically, a reflector in accordance with the invention comprises a base plane and a pattern of microelements having maximum lateral dimensions less than 125 micrometers and smooth, continuous mold-formed surfaces arising from the base plane. Such a reflector surface can be made using a master formed by covering a substrate with photoresist, exposing the resist to define a pattern of microelements having maximum lateral dimensions less than about 125 micrometers and heating the substrate to partially melt the resist elements thereby obtaining smooth-surfaced microelements. The master can be used to form an embossing surface or mold, which, in turn, can be used to make a microtextured reflecting surfaces. A preferred reflecting surface is composed of closely packed, smooth-surfaced spherical segments having diameters of twenty-five microns, altitudes of four microns. Advantageously random segments are disposed between successive spherical segments. The preferred reflector possesses reflecting characteristics superior to conventional isotropic reflectors.

Inventors

  • 👤 Greg E. Blonder

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 13:44
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133553; Y; Y10; Y10S; Y10S359/00; Y10S359/90

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 79 words
A method for making a microtextured reflecting surface comprising the steps of: providing a substrate; photolithographically forming on said substrate a pattern of photoresist areas corresponding to the bases of segments to be formed on said reflecting surface; heating said photoresist areas to provide smooth, continuous surfaces within said bases; forming a master having a surface texture corresponding to the surface of the resist-covered surface after heating; and forming a reflecting surface having the surface texture of said master.
Claim 2
Independent Claim 79 words
A method for making a microtextured reflecting surface comprising the steps of: providing a substrate; photolithographically forming on said substrate a pattern of photoresist areas corresponding to the bases of segments to be formed on said reflecting surface; heating said photoresist areas to provide smooth, continuous surfaces within said bases; forming a master having a surface texture corresponding to the surface of the resist-covered surface after heating; and forming a reflecting surface having the surface texture of said master.
Claim 3
Dependent Claim 20 words
The method of claim 1, wherein said photoresist elements have a maximum lateral dimension of less than about 125 micrometers.

References Cited (Backward Citations)

US2951419A Cited
US3253971A Cited
US4106859A Cited
US4249801A Cited
US4185895A Cited
US4431272A Cited
US4519678A Cited
US4712867A Cited
US4706173A Cited
US4991940A Cited
US5128787A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-02-21 1997-08-23 1998-02-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-02-21 2001-08-23 2002-02-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-02-21 2005-08-23 2006-02-22 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag