Folded variable birefringerence zeroth order hybrid aligned liquid crystal apparatus
First Claim
1. A liquid cell, comprisinga birefringent liquid crystal material in a generally hybrid aligned configuration,a pair of surfaces containing the birefringent liquid crystal material therebetween, said liquid crystal cell being configured to operate in a birefringent mode with relatively minimal color dispersion when supplied with polarized light,the birefringent liquid crystal material being preconditioned such that optical phase can be modulated to switch between two retardations to provide relatively minimal optical phase retardation and increased optical phase retardation and giving the birefringent mode minima and maxima for a given operation.
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Accused Products
Abstract
A reflective variable birefringence liquid crystal cell has an active matrix substrate, a birefringent material, a pair of surfaces containing the birefringent material therebetween, the birefringent material in proximity to the active matrix substrate having homeotropic alignment to eliminate the affect of varying cell thickness due to peaks and valleys in the surface of the active matrix substrate, the birefringent material in proximity to the other surface being switchable to provide relatively minimal optical phase retardation and increased optical phase retardation, the liquid crystal material may be preconditioned to assume a particular alignment to provide for a prescribed amount of retardation in one operational state of the cell.
90 Citations
53 Claims
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1. A liquid cell, comprising
a birefringent liquid crystal material in a generally hybrid aligned configuration, a pair of surfaces containing the birefringent liquid crystal material therebetween, said liquid crystal cell being configured to operate in a birefringent mode with relatively minimal color dispersion when supplied with polarized light, the birefringent liquid crystal material being preconditioned such that optical phase can be modulated to switch between two retardations to provide relatively minimal optical phase retardation and increased optical phase retardation and giving the birefringent mode minima and maxima for a given operation.
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15. A liquid crystal cell, comprising
a birefringent liquid crystal material configured in generally hybrid aligned configuration, a pair of surfaces containing the birefringent liquid crystal material therebetween, said liquid crystal cell being configured to operate in a birefringent mode with relatively minimal color dispersion when supplied with polarized light, the birefringent liquid crystal material being preconditioned in response to a field and operative to provide respective optical phase retardation conditions, thereby to switch between two retardations, one to provide relatively minimal optical phase retardation and the other to provide increased optical phase retardation, and a plane polarizer selectively to block or to transmit light to or from one of said surfaces as a function of the direction of the plane of polarization of such light.
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17. A birefringent liquid crystal apparatus configured to operate in a birefringent mode with relatively minimal color dispersion effects, comprising,
at least one polarizer for polarizing incident light; -
a pair of surfaces; liquid crystal material between said surfaces in generally hybrid aligned configuration, the liquid crystal material in relative proximity to one surface exhibiting generally homeotropic alignment, the liquid crystal material in relative proximity to the other surface exhibiting generally homogeneous alignment, means to alter alignment of at least one of said alignments to change the optical phase retardation characteristic exhibited by the liquid crystal material in the apparatus with substantially minimal color dispension, and reflector means for reflecting light transmitted in said liquid crystal material back through said liquid crystal material. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A reflective liquid crystal apparatus operative in a birefringent mode with relatively minimal color dispersion effects when supplied with polarized light, comprising,
an optically reflective semiconductor substrate having electrical components, a further substrate, liquid crystal between said substrates in a generally hybrid aligned configuration, electrical means cooperative with electrical components of said semiconductor substrate to apply electric field to liquid crystal material to alter the optical phase retardation characteristics of the liquid crystal, the liquid crystal proximate said semiconductor substrate being aligned generally homeotropically, and the liquid crystal proximate said further substrate being aligned generally homogeneously, said electrical means being operative to apply a field to buttress such homeotropic alignment of the liquid crystal relatively proximate said semiconductor substrate to precondition the apparatus to switch optical phase retardation characteristics thereby to control light, and the further substrate being able to transmit light therethrough for transmission through the liquid crystal and reflection by said optically reflective semiconductor substrate.
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31. A liquid crystal apparatus configured to operate in a birefringent mode with relatively minimal color dispersion effects when supplied with polarized light, comprising
a source of polarized light or a polarizer, first and second substrates, one substrate having a relatively unsmooth surface and the other having a relatively smooth surface, birefringent material between the substrates, said birefringent material comprising liquid crystal material, said liquid crystal material being in a generally hybrid aligned configuration, said liquid crystal material in relative proximity to said relatively unsmooth surface having generally homeotropic alignment, said liquid crystal material in relative proximity to said relative smooth surface having generally homogeneous alignment, and field applying means selectively to apply a field input to said liquid crystal material to precondition the liquid crystal material to provide one optical phase retardation and to provide a different optical phase retardation.
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34. A display apparatus, comprising,
a source of polarized light, a liquid crystal display for selectively modulating light, said liquid crystal display comprising a semiconductor substrate and a further substrate with birefringent liquid crystal material in a generally hybrid alignment configuration between said substrates, said liquid crystal cell being configured to operate in a birefringent mode with relatively minimal color dispersion, said source being operative to provide light to pass into said liquid crystal material through said further substrate toward said semiconductor substrate, and means to reflect light to pass through said liquid crystal material and subsequently through said further substrate, the liquid crystal material being operative in response to a field input to change the optical phase retardation characteristics of the liquid crystal material.
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42. A birefringent liquid crystal optical apparatus, comprising,
a liquid crystal cell including a pair of substrates and a birefringent liquid crystal material in a generally hybrid alignment configuration between the substrates, said liquid crystal cell being configured to operate in a birefringent mode with relatively minimal color dispersion when supplied with polarized light, means for applying electric field between said substrates to alter liquid crystal alignment and therefore optical phase retardation characteristics of liquid subject to such field, one of said substrates including means for causing generally homeotropic alignment of liquid crystal material that is relatively proximate to said substrate, said means for applying electric field comprising means to buttress such homeotropic alignment to precondition the liquid crystal material for altering optical phase retardation characteristics.
- 47. A method of variably phase retarding light by a liquid crystal cell operable in a birefringence mode when supplied with polarized light and in which birefringent operationally nematic liquid crystal material is configured in a generally hybrid alignment configuration to be in substantially homeotropic alignment with one surface and substantially homogeneous alignment with another surface of the liquid crystal cell, comprising applying a field to precondition the orientation of liquid crystal material in the liquid crystal cell to buttress such substantially substantially homeotropic alignment, and applying an input to the cell to change the orientation of at least some of the liquid crystal material thereby to alter the optical phase retardation of light transmitted in the liquid crystal material without substantial color dispersion.
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51. A birefringent liquid crystal apparatus configured to operate in a birefringent mode, comprising,
a liquid crystal cell including a pair of surfaces and liquid crystal material between said surfaces in generally hybrid, generally untwisted aligned configuration, means to alter alignment of at least one of said alignments to change the optical phase retardation characteristic exhibited by the liquid crystal material in the apparatus, and reflector means for reflecting light transmitted in said liquid crystal material back through said liquid crystal material, the birefringent liquid crystal material being preconditioned such that optical phase can be modulated to switch between two retardations to provide relatively minimal optical phase retardation and increased optical phase retardation and giving the birefringent mode minima and maxima for a given operation, said switching being between approximately zero and 1/4 lambda.
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52. A birefringent liquid crystal apparatus configured to operate in a birefringent mode, comprising,
a liquid crystal cell including a pair of surfaces and liquid crystal material between said surfaces in generally hybrid, generally untwisted aligned configuration, means for applying electric field to alter alignment of at least one of said alignments to change the optical phase retardation characteristic exhibited by the liquid crystal material in the apparatus, and reflector means for reflecting light transmitted in said liquid crystal material back through said liquid crystal material, said liquid crystal material having approximately 1/4 wave optical phase retardation characteristics in one operative condition thereof in response to application of a relatively low voltage electric field by the means for applying, and approximately zero wave optical phase retardation characteristics in a different operative condition thereof in response to application of a relatively larger voltage electric field by the means for applying.
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53. A reflective liquid crystal apparatus operative in a birefringent mode when supplied with polarized light, comprising,
an optically reflective semiconductor substrate having electrical components, a further substrate, liquid crystal between said substrates in a generally untwisted hybrid aligned configuration, electrical means cooperative with electrical components of said semiconductor substrate to apply electric field to liquid crystal material to alter the optical phase retardation characteristics of the liquid crystal, the liquid crystal proximate said semiconductor substrate being aligned generally homeotropically, and the liquid crystal proximate said further substrate being aligned generally homogeneously, said electrical means being operative to apply a field to buttress such homeotropic alignment of the liquid crystal relatively proximate said semiconductor substrate to precondition the apparatus to switch optical phase retardation characteristics thereby to control light, said liquid crystal material being operable in response to characteristics of the field to switch between two optical phase retardation effects by approximately 1/4 lambda, and the further substrate being able to transmit light therethrough for transmission through the liquid crystal and reflection by said optically reflective semiconductor substrate.
Specification