Polymer dispersed liquid crystal display with birefringence of the liquid crystal at least 0.23

A liquid crystal apparatus comprising:

• a containment medium, a birefringent liquid crystal material wherein the difference between the ordinary and the extraordinary indices of refraction of said liquid crystal material is greater than or equal to about 0.23, said liquid crystal material dispersed in plural volumes in said containment medium wherein said volumes have a mean size from about 0.5 to 3.0 microns, the thickness of said containment medium between about 8 and 18 microns, and a pleochroic dye contained in said liquid crystal material that conforms to the structure thereof wherein the concentration of said dye in said liquid crystal material is on the order between about 0.6% and 1.2%.

A liquid crystal apparatus comprising:

• a containment medium, a birefringent liquid crystal material wherein the difference between the ordinary and extraordinary indices of refraction of said liquid crystal material is greater than or equal to about 0.23, said liquid crystal material dispersed in plural volumes in said containment medium wherein said volumes have a mean size from about 0.5 to 2.5 microns, the thickness of said containment medium between about 8 and 18 microns, and a pleochroic dye contained in said liquid crystal material that conforms to the structure thereof wherein the concentration of said dye in said liquid crystal material is on the order of between about 0.6% and 1.2%.

A liquid crystal apparatus comprising:

• a containment medium, a birefringent liquid crystal material wherein the difference between the ordinary and extraordinary indices of refraction of said liquid crystal material is between about 0.23 and 0.30, said liquid crystal material dispersed in plural volumes in said medium wherein said volumes have a mean volume diameter of between about 0.5 and 2.5 microns, said medium producing a generally distorted alignment of said liquid crystal material which in response to such alignment at least one of scatters and absorbs light and which in response to an electrical field reduces the amount of such scattering or absorption, said medium having a thickness between about 5 and 18 microns, and a pleochroic dye contained in said liquid crystal material that conforms to the structure thereof with the concentration of said dye in said liquid crystal material on the order of between about 0.5% and 3.0%.

A liquid crystal apparatus comprising:

• a containment medium, a birefringent liquid crystal material wherein the difference between the ordinary and extraordinary indices of refraction of said liquid crystal material is between about 0.23 and 0.30, said liquid crystal material dispersed in substantially spherical capsules in said medium wherein said capsules have a mean diameter of between about 0.5 and 2.5 microns, said medium producing a generally distorted alignment of said liquid crystal material which in response to such alignment at least one of scatters and absorbs light and which in response to an electrical field reduces the amount of such scattering or absorption, electrode-coated substrate means for applying said electric field and said medium disposed therebetween and having a thickness between about 8 and 18 microns, and a pleochroic dye contained in said liquid crystal material that conforms to the structure thereof with the concentration of said dye in said liquid crystal material on the order of between about 0.6% and 1.2%.

A liquid crystal apparatus comprising:

• a containment medium, a birefringent liquid crystal material wherein the difference between the ordinary and extraordinary indices of refraction of said liquid crystal material is greater than or equal to about 0.23, said liquid crystal material dispersed in plural volumes in said containment medium wherein said volumes have a means volume diameter from about 0.5 to 2.5 microns, the thickness of said containment medium between about 8 and 18 microns, a blue pleochroic dye contained in said liquid crystal material that conforms to the structure thereof wherein the concentration of said dye in said liquid crystal material is on the order of between about 0.6% and 2.0%, and a fluorescent reflector disposed on a non-viewing side of said containment medium.

A display comprising:

• a containment medium, a birefringent liquid crystal material wherein the difference between the ordinary and extraordinary indices of refraction of said liquid crystal material is greater than or equal to about 0.23, said liquid crystal material dispersed in plural volumes in said containment medium, a pleochroic dye contained in said liquid crystal material that conforms to the structure thereof, and a fluorescent reflector disposed on a non-viewing side of said containment medium, the color of said dye and said reflector selected to be substantially complementary to each other to enhance the contrast of the display.

A method of making a liquid crystal apparatus, comprising:

• forming a plurality of volumes of a birefringent liquid crystal material and a pleochroic dye that conforms to the structure thereof in a containment medium such that the walls of said volumes produce a distorted alignment of said liquid crystal material which in response to such alignment at least one of scatters and absorbs light and which in response to an electric field reduces the amount of such scattering or absorption, and selecting said liquid crystal material such that the difference between its ordinary and extraordinary indices of refraction is greater than or equal to about 0.23.

A method of making a liquid crystal apparatus, comprising:

• forming a plurality of volumes of a birefringent liquid crystal material and a pleochroic dye that conforms to the structure thereof in a containment medium such that the walls of said volumes produce a distorted alignment of said liquid crystal material which in response to such alignment at least one of scatters and absorbs light and which in response to an electric field reduces the amount of such scattering or absorption wherein said volumes have a mean size of between about 0.5 and 2.5 microns, selecting said liquid crystal material such that the difference between its ordinary and extraordinary indices of refraction is greater than or equal to about 0.23 wherein the concentration of said pleochroic dye in said liquid crystal material is on the order of between about 0.6% and 1.2%, and forming said containment medium to have a thickness of between about 8 and 18 microns.