Illumination of a liquid crystal display

Claim 1

In a liquid crystal display including a liquid crystal cell and means for illuminating said cell, said cell comprising: first and second light transmissive substrates, each having first and second major surfaces, said substrates being disposed such that said first surfaces face one another and said second surface of said first substrate being the light entry surface for illumination of the cell; electrode structures on said first major surfaces; a liquid crystal between said substrates, said liquid crystal having a directior wherein said cell has a principal viewing plane which contains the midpoint director and a normal to one of said second major surfaces; the improvement comprising: said means for illuminating said cell providing an output beam which is substantially collimated in said principal viewing plane and which is substantially uncollimated in an orthogonal plane which is substantially perpendicular to said principal viewing plane and contains said normal; wherein the thickness of said liquid crystal between said substrates corresponds to the first Gooch-Tarry minimum for said cell at a wavelength between about 400 and 700 nanometers; and wherein the angular distribution of the uncollimated light in said orthogonal plane is substantially a Lambert distribution.

Claim 9

A method for illuminating a liquid crystal cell comprising a liquid crystal between electrode structures on the surfaces of first and second substrates and having a principal viewing plane which contains the midpoint director of the liquid crystal and a normal to a major surface of one of said substrates, said method comprising the step of illuminating said cell with a beam of light which is substantially collimated in said principal viewing plane and which is substantially uncollimated in an orthogonal plane which is substantially perpendicular to said principal viewing plane and contains said normal the thickness of said liquid crystal corresponds to the first Gooch-Tarry minimum for said cell at a wavelength between about 400 and 700 nanometers, and wherein said liquid crystals is aligned so that its director is oriented in one direction adajcent said first substrate and its director is oriented in an orthogonal direction adjacent said second substrate.

Claim 10

A method for illuminating a liquid crystal cell comprising a liquid crystal between electrode structures on the surfaces of first and second substrates and having a principal viewing plane which contains the midpoint director of the liquid crystal and a normal to a major surface of one of said substrates, said method comprising the step of illuminating said cell with a beam of light which is substantially collimated in said principal viewing plane and which is substantially uncollimated in an orthogonal plane which is substantially perpendicular to said principal viewing plane and contains said normal the thickness of said liquid crystal corresponds to the first Gooch-Tarry minimum for said cell at a wavelength between about 400 and 700 nanometers, and wherein said liquid crystals is aligned so that its director is oriented in one direction adajcent said first substrate and its director is oriented in an orthogonal direction adjacent said second substrate.