Surface stabilized ferroelectric liquid crystal devices

Claim 2

A process of making a liquid crystal device including a ferroelectric liquid crystal, molecules, having long axes, in a bulk of said liquid crystal forming helices and first and second means for containing said liquid crystal, said process comprising the steps of: forming layers of said molecules at an angle different from 90° to said first and second means; aligning the molecules of said liquid crystal adjacent to at least said first means at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, said aligning step allowing said molecules to move between at least two particular orientations; and suppressing the formation of said helices.

Claim 3

A process as in claim 1 wherein said forming step includes the step of displacing, in a smectic C phase or at lower temperatures in a smectic A phase, one of said first and second means relative to the other in a direction normal to said layers.

Claim 4

A process as in claim 1 wherein said forming step includes the step of cooling said liquid crystal into a smectic C phase in the presence of a strong magnetic field.

Claim 5

A process as in claim 1 wherein said forming step includes the steps of: applying polar anisotropic boundary conditions to said first and second means with the anisotropy reversed by 180°; cooling said liquid crystal to a smectic A phase; and cooling said liquid crystal from a smectic A phase to another smectic phase.

Claim 6

A process for making a liquid crystal device including a ferroelectric liquid crystal, molecules, having long axes, in a bulk of said liquid crystal forming helices and first and second means for containing said liquid crystal, said process comprising the steps of: disposing said first means a distance from said second means less than the distance at which said helices form; first cooling said liquid crystal from at least one of an isotropic and nematic phases to a smectic A phase; aligning the molecules of said liquid crystal adjacent to said first and second means at angles Ω 1 (α 1 ) and Ω 2 (α 2 ), respectively, from the normals to said first and second means, respectively, said angles Ω 1 (α 1 ) and Ω 2 (α 2 ) being different predetermined functions of angles α 1 and α 2 , respectively, said angles α 1 and α 2 being angles between reference vectors in respective planes parallel to said first means and to said second means, respectively, and a projection of said long axes of said molecules onto said planes, said molecules being free to move between at least two particular orientations; orienting said liquid crystal during said first cooling step to form said smectic A liquid crystal in flat layers; and second cooling of said liquid crystal from said smectic A phase to another phase.

Claim 7

A process for making a liquid crystal device including a ferroelectric liquid crystal, molecules, having long axes, in a bulk of said liquid crystal forming helices and first and second means for containing said liquid crystal, said process comprising the steps of: disposing said first means a distance from said second means less than the distance at which said helices form; first cooling said liquid crystal from at least one of an isotropic and nematic phases to a smectic A phase; aligning the molecules of said liquid crystal adjacent to said first and second means at angles Ω 1 (α 1 ) and Ω 2 (α 2 ), respectively, from the normals to said first and second means, respectively, said angles Ω 1 (α 1 ) and Ω 2 (α 2 ) being different predetermined functions of angles α 1 and α 2 , respectively, said angles α 1 and α 2 being angles between reference vectors in respective planes parallel to said first means and to said second means, respectively, and a projection of said long axes of said molecules onto said planes, said molecules being free to move between at least two particular orientations; orienting said liquid crystal during said first cooling step to form said smectic A liquid crystal in flat layers; and second cooling of said liquid crystal from said smectic A phase to another phase.

Claim 8

A process as in claim 5 wherein said first cooling step is from a nematic phase and said orienting step comprises the step of applying a field parallel to said first and second means.

Claim 9

A process as in claim 5 wherein said orienting step comprises the step of gently moving said first means parallel to and with respect to said second means.

Claim 10

A process as in claim 5 wherein: said first cooling step is from a nematic phase; and said orienting step comprises the step of gently moving said first means parallel to and with respect to said second means while applying a magnetic field parallel to said first and second means.

Claim 11

A process of making a liquid crystal device including a ferroelectric liquid crystal, molecules in a bulk of said liquid crystal forming helices and first and second means for containing said liquid crystal, said process comprising the steps of: applying to portions of said first and second means a surface treatment to align layers of said liquid crystal; applying to portions of said first and second means a surface treatment to align long axes of said molecules in any of a plurality of orientations; disposing said first means a distance from said second means less than the distance at which said helices form; first cooling of said liquid crystal from one of the nematic and isotropic phases to a smectic A phase; and second cooling of said liquid crystal from said smectic A phase to another phase.

Claim 12

A process of making a liquid crystal device including a ferroelectric liquid crystal, molecules in a bulk of said liquid crystal forming helices and first and second means for containing said liquid crystal, said process comprising the steps of: applying to portions of said first and second means a surface treatment to align layers of said liquid crystal; applying to portions of said first and second means a surface treatment to align long axes of said molecules in any of a plurality of orientations; disposing said first means a distance from said second means less than the distance at which said helices form; first cooling of said liquid crystal from one of the nematic and isotropic phases to a smectic A phase; and second cooling of said liquid crystal from said smectic A phase to another phase.

Claim 13

A process as in claim 9 wherein said first cooling step is from said isotropic phase and said process further comprises the step of applying a magnetic field perpendicular to said layers during said first cooling step.

Claim 14

A process of making a liquid crystal device including a ferroelectric liquid crystal, molecules in a bulk of said liquid crystal forming helices and first and second means for containing said liquid crystal, said process comprising the steps of: applying to portions of said first and second means a surface treatment to align layers of said liquid crystal; applying to other portions of said first and second means a surface treatment to align long axes of said molecules in any of a plurality of orientations; disposing said first means a distance from said second means less than the distance at which said helices form; and cooling said liquid crystal from one of the nematic and isotropic phases to another phase.

Claim 15

A process of making a liquid crystal device including a ferroelectric liquid crystal, molecules in a bulk of said liquid crystal forming helices and first and second means for containing said liquid crystal, said process comprising the steps of: applying to portions of said first and second means a surface treatment to align layers of said liquid crystal; applying to other portions of said first and second means a surface treatment to align long axes of said molecules in any of a plurality of orientations; disposing said first means a distance from said second means less than the distance at which said helices form; and cooling said liquid crystal from one of the nematic and isotropic phases to another phase.

Claim 16

A process as in claim 11 wherein said cooling step is from said isotropic or nematic phase and said process further comprises the step of applying a DC electric field across said first and second means during said cooling step.

Claim 17

A process as in claim 11 wherein said cooling step is from said isotropic or nematic phase and said process further comprises the step of applying a magnetic field perpendicular to said layers during said cooling step.

Claim 18

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; and first and second means, each not normal to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations.

Claim 19

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; and first and second means, each not normal to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations.

Claim 20

A device as in claim 14 wherein said angle Ω(α) is close to 90°.

Claim 21

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; and first and second means, each transverse to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means varying over the area of said first and second means and being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations.

Claim 22

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; and first and second means, each transverse to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means varying over the area of said first and second means and being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations.

Claim 23

A device as in claim 16 wherein said distance varies in discrete steps.

Claim 24

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; first and second means, each transverse to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations; and means for heating a portion of said liquid crystal to a sufficient extent to create states different from states in unheated portions of said liquid crystal.

Claim 25

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; first and second means, each transverse to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations; and means for heating a portion of said liquid crystal to a sufficient extent to create states different from states in unheated portions of said liquid crystal.

Claim 26

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; first and second means, each transverse to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, and not 90° for all values of α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations.

Claim 27

A liquid crystal device comprising: a quantity of ferroelectric liquid crystal having a plurality of adjacently disposed layers each comprised of a plurality of molecules, each molecule having a long axis, said molecules of said layers in a bulk of said liquid crystal forming helices having axes perpendicular to said layers; first and second means, each transverse to and contiguous with said layers, for containing said liquid crystal, at least said first means aligning the long axes of said molecules adjacent thereto at an angle Ω(α) from the normal to said first means, said angle Ω(α) being a predetermined function of an angle α, and not 90° for all values of α, said angle α being an angle between a reference vector in a plane parallel to said first means and a projection of said long axes of said molecules onto said plane, the distance between said first and second means being less than the distance at which said helices form in the absence of an electric field, said first and second means causing said long axes to assume one of a plurality of stable orientations.