Light modulating material comprising a liquid crystal dispersion in a plastic matrix

A material capable of modulating light comprising droplets of liquid crystal dispersed in cured epoxy resin, said liquid crystal being soluble in uncured epoxy resin and said droplets being spontaneously formed during curing.

A thermally responsive, light modulating material capable of reversibly changing between opaque and light transmissive states comprising droplets of liquid crystal dispersed in cured epoxy resin, said liquid crystal being soluble in the uncured epoxy resin and said droplets being spontaneously formed during curing, said liquid crystal having in its isotropic phase an optical index of refraction such as to permit transmission of incident light, and having in its liquid crystalline phase an optical index of refraction such that incident light is scattered and said material is opaque.

An electrically responsive device capable of being reversibly switched between opaque and light transmissive states comprising electrode means, a synthetic resin matrix between said electrode means, droplets of nematic liquid crystal dispersed in said resin matrix, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof, and a voltage source connected to said electrode means for establishing an electric field across said resin matrix and liquid crystal droplets, said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of the matrix so that incident light is passed through said device in the presence of an electric field, and having its other index refraction such that incident light is scattered and said device is opaque in the absence of an electric field.

A light polarizing material comprising droplets of liquid crystal dispersed in a matrix of solid, light-transmissive resin, said liquid crystal being soluble in the matrix-forming composition, said droplets being spontaneously formed from solution in the composition during solidification thereof, and said liquid crystal having an ordinary index of refraction in its liquid crystalline phase such that, when said polarizing material is strained in one direction, one component of plane polarized incident light will be scattered and the other component will be transmitted therethrough.

An electrically responsive, light modulating device comprising spaced, transparent electrode means, a sheet or film formed by a light transmissive synthetic resin matrix containing droplets of liquid crystal, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidification thereof, and a voltage source connected to said electrode means for establishing an electric field across said sheet or film, said sheet or film being stretched so that light is transmitted through said device and is polarized when said electric field is off, and said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of said sheet or film, whereby unpolarized light is transmitted through said device when the electric field is on.

A resin matrix containing droplets of nematic liquid crystal, said liquid crystal being soluble in the matrix-forming composition and said droplets being spontaneously formed from solution in the composition during solidfication thereof, said liquid crystal having an ordinary optical index of refraction similar to the index of refraction of said matrix so that at least one component of incident light is transmitted when the liquid crystal directors are aligned and so that incident light is scattered when the liquid crystal directors are misaligned.

An electrically addressable light modulating device capable of being reversibly switched between a polarizing mode and a non-polarizing light transmitting mode comprising:

• a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix,
• said microdroplets having their optical axes aligned in one direction in the plane of said matrix in said polarizing mode and normal to the plane of said matrix in said non-polarizing, light transmitting mode, and
• means to deliver a field effective to switch said device from one of said modes to the other.

A light modulating material comprising a solid sheet formed by a light transmitting synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being arranged so that their optical axes will scatter at least one component of light incident on a surface of said sheet and being responsive to a field whereby said optical axes are aligned normal to said surfare so that incident light is transmitted through said sheet.

A light modulating material comprising a solid sheet formed by a light transmitting synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being arranged with their optical axes normal to a surface of said sheet so that incident light on said surface is transmitted through said material and being responsive to a field or to strain whereby said optical axes are caused to shift to an orientation effective to scatter at least one component of said incident light.

A field responsive, light modulating device comprising a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being oriented with their optical axes aligned in one direction, and means for establishing a field effective to shift the alignment of said optical axes.

A field responsive, light modulating material comprising a light transmissive synthetic resin matrix containing dispersed microdroplets of nematic liquid crystal having an ordinary index of refraction similar to the refractive index of said matrix, said microdroplets being oriented so that their optical axes are aligned in one direction and being responsive to a field whereby the alignment of said optical axes is changed.

A method of making a light modulating material comprising the steps of dissolving liquid crystal in a solidifiable, light transmissive resin matrix-forming composition, and thereafter solidifying said composition and causing spontaneous formation of liquid crystal droplets.

A method of making a material capable of exhibiting contrasting response from opaque to light transmissive conditions comprising the steps of stirring together liquid crystal, epoxy resin, and curing agent to form a mixture in which the liquid crystal is dissolved, and curing said mixture to form a solid which contains droplets of liquid crystal spontaneously formed upon curing.

A method of making a light modulating material comprising the steps of dissolving liquid crystal in a resin capable of being cured to form a clear matrix, said liquid crystal having the characteristic of spontaneously forming droplets upon curing of said resin, and thereafter curing said resin to form a matrix containing a uniform dispersion of liquid crystal droplets, said liquid crystal being further characterized by an ordinary optical index of refraction similar to that of the cured resin so that at least one component of incident light will be transmitted when the liquid crystal directors are aligned and so that incident light will be scattered when the liquid crystal directors are misaligned.

A method of making a liquid crystal microdroplet containing, light modulating material comprising the steps of:

• dissolving liquid crystal in a light transmissive synthetic resin matrix-forming composition,
• establishing a field effective to align the optical axes of the microdroplets, and
• solidfying said composition in the presence of said field whereby the dispersed microdroplets that form spontaneously during solidification have their optical axes aligned by said field.