Liquid crystal variable color density lens and eye protective devices incorporating the same

An electro-optical variable color variable transmissivity lens assembly comprising:

• a polymer lens housing, including exterior lens panels encompassing a central cavity, said panels being adapted to have various degrees of curvature;
• a composition of a phase change guest-host liquid crystal/dyes complex, possessing positive dielectric anisotropy, situated and aligned within said cavity of the polymer lens housing,
• electronic photodetecting and oscillating/driving circuit system means, for operation of the said electro-optical lens to alter the alignment of the composition in response to changes in light conditions;
• the composition of the liquid crystal/dye complex of the phase change guest-host system being selected to assume an optically clear state of cholesteric phase in a quiescent state, within said lens cavity, without exhibiting focal conic light scattering structures;
• the composition of the liquid crystal/dye complex of the phase change guest-host system being selected to undergo a gradual transformation from its quiescent cholesteric state to a homeotropic nematic state upon voltage transition from zero to maximum voltage and vice versa, without producing dynamic scattering stages;
• and
• the composition of the colored liquid crystal/dye complex of the phase change guest/host system being selected to reach the optically clear nematic homeotropic stage at a saturation voltage ranging from 4 to about 6.5 VAC.

A variable color density optical device comprising:

• a first variable transmissivity lens element;
• a second variable transmissivity lens element;
• a frame element supporting the first and second lens elements in a position corresponding to the left and right eyes of the user;
• a control component, mounted in association with the frame element, the control component including one or more light sensors for sensing the intensity of light in the vicinity of the first and second lens elements, regulator circuitry adapted to regulate the voltage level in response to said light sensor, square wave generation circuitry adapted to generate square wave alternating current in response to regulated direct current level input provided by said regulator circuitry, conductive means for carrying said signals to the first and second lens elements, and power source means for supplying electrical power to said sensors and said circuitry;
• wherein each of the first and second lens elements includes a central cavity enclosing a composition of a phase change guest-host liquid crystalline/dye complex mixture, said guest-host composition being characterized by positive dielectric anisotropy and being aligned by homeotropic boundaries created by first and second alignment layers formed on each of the lens elements;
• and
• wherein each lens element includes a conductive layer juxtaposed about said central cavity and electrically connected to said conductive means, such that said electrical signals respectively delivered to said conductive layers of the lens elements cause an alternation in the alignment of said composition system from an optically clear quiescent cholesteric stage, gradually and without light scattering occurrences, to another optically clear end state, in the nature of a homeotropic nematic alignment, in response to variations in the light intensity sensed by said sensors.