Liquid crystal composition having an improved temperature dependence of response speed, liquid crystal device and display apparatus

Claim 2

A liquid crystal composition having a temperature range where the composition assumes chiral smectic C phase, said temperature range including: a) a first temperature range where the liquid crystal composition shows a cone angle in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature.

Claim 3

A liquid crystal composition according to claim 1, wherein the liquid crystal composition also has a temperature range of smectic A phase, and the mediate temperature appears in a temperature range between (Tc-10) °C. and 10° C., wherein Tc denotes a phase transition temperature from the smectic A phase to the chiral smectic C phase.

Claim 4

A liquid crystal composition according to claim 1, wherein the liquid crystal composition also has a temperature range of smectic A phase, and the mediate temperature appears in a temperature range between (Tc-10) °C. and 20° C., wherein Tc denotes a phase transition temperature from the smectic A phase to the chiral smectic C phase.

Claim 5

A liquid crystal composition according to claim 1, wherein the liquid crystal composition also has a temperature range of smectic A phase, and the mediate temperature appears in a temperature range between (Tc-10) °C. and 30° C., wherein Tc denotes a phase transition temperature from the smectic A phase to the chiral smectic C phase.

Claim 6

A liquid crystal composition according to claim 1, wherein the composition also has a temperature range of cholesteric phase.

Claim 7

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in a temperature range where the composition assumes chiral smectic C phase, said temperature range including: a) a first temperature range where the liquid crystal composition shows a cone angle in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature.

Claim 8

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in a temperature range where the composition assumes chiral smectic C phase, said temperature range including: a) a first temperature range where the liquid crystal composition shows a cone angle in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature.

Claim 9

A device according to claim 6, wherein at least one of said pair of substrates is provided with a uniaxial alignment axis.

Claim 10

A device according to claim 7, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 11

A device according to claim 6, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which are parallel and the same as or opposite to each other.

Claim 12

A device according to claim 9, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 13

A device according to claim 6, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which intersect each other.

Claim 14

A device according to claim 11, wherein said respective directions intersect each other at an angle of 2-15 degrees.

Claim 15

A device according to claim 12, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 16

A device according to claim 6, wherein said liquid crystal composition also has a temperature range of smectic A phase, is placed in the chiral smectic C phase through cooling from the smectic A phase and has the mediate temperature in a temperature range between (Tc-10) °C. and 10° C., wherein Tc denotes a phase temperature from the smectic A phase to the chiral smectic C. phase.

Claim 17

A device according to claim 6, wherein said liquid crystal composition also has a temperature range of smectic A phase, is placed in the chiral smectic C phase through cooling from the smectic A phase and has the mediate temperature in a temperature range between (Tc-10) °C. and 20° C., wherein Tc denotes a phase temperature from the smectic A phase to the chiral smectic C phase.

Claim 18

A device according to claim 6, wherein said liquid crystal composition also has a temperature range of smectic A phase, is placed in the chiral smectic C phase through cooling from the smectic A phase and has the mediate temperature in a temperature range between (Tc-10) °C. and 30° C., wherein Tc denotes a phase temperature from the smectic A phase to the chiral smectic C phase.

Claim 19

A device according to claim 6, wherein said liquid crystal composition also has temperature ranges of cholesteric phase and smectic A phase, respectively, and is placed in the chiral smectic C phase through cooling from the cholesteric phase and the smectic A phase.

Claim 20

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic C phase, said temperature range including: a) a first temperature range where the liquid crystal composition shows a cone angle H in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle H in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ d) δ<α, and e) H>θa>H/2.

Claim 21

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic C phase, said temperature range including: a) a first temperature range where the liquid crystal composition shows a cone angle H in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle H in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ d) δ<α, and e) H>θa>H/2.

Claim 22

A device according to claim 16, wherein at least one of said pair of substrates is provided with a uniaxial alignment axis.

Claim 23

A device according to claim 19, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 24

A device according to claim 18, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which are parallel and the same as or opposite to each other.

Claim 25

A device according to claim 21, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 26

A device according to claim 18, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which intersect each other.

Claim 27

A device according to claim 23, wherein said respective directions intersect each other at an angle of 2-15 degrees.

Claim 28

A device according to claim 24, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 29

A device according to claim 18, wherein said liquid crystal composition also has a temperature range of smectic A phase, is placed in the chiral smectic C phase through cooling from the smectic A phase and has the mediate temperature in a temperature range between (Tc-10) °C. and 10° C., wherein Tc denotes a phase temperature from the smectic A phase to the chiral smectic C phase.

Claim 30

A device according to claim 18, wherein said liquid crystal composition also has a temperature range of smectic A phase, is placed in the chiral smectic C phase through cooling from the smectic A phase and has the mediate temperature in a temperature range between (Tc-10) °C. and 20° C., wherein Tc denotes a phase temperature from the smectic A phase to the chiral smectic C phase.

Claim 31

A device according to claim 18, wherein said liquid crystal composition also has a temperature range of smectic A phase, is placed in the chiral smectic C phase through cooling from the smectic A phase and has the mediate temperature in a temperature range between (Tc-10) °C. and 30° C., wherein Tc denotes a phase temperature from the smectic A phase to the chiral smectic C phase.

Claim 32

A device according to claim 18, wherein said liquid crystal composition also has temperature ranges of cholesteric phase and smectic A phase, respectively, and is placed in the chiral smectic C phase through cooling from the cholesteric phase and the smectic A phase.

Claim 33

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in a temperature range where the composition assumes chiral smectic C phase, and voltage application means for applying voltages across the liquid crystal composition, said temperature range of chiral smectic C phase including: a) a first temperature range where the liquid crystal composition shows a cone angle in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature.

Claim 34

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in a temperature range where the composition assumes chiral smectic C phase, and voltage application means for applying voltages across the liquid crystal composition, said temperature range of chiral smectic C phase including: a) a first temperature range where the liquid crystal composition shows a cone angle in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature.

Claim 35

A display apparatus according to claim 30, further including control means for controlling the voltage application means.

Claim 36

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition disposed between the substrates, and voltage application means for applying voltages across the liquid crystal composition; said liquid crystal composition being placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic C phase, said temperature range including: a) a first temperature range where the liquid crystal composition shows a cone angle H in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle H in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ, d) δ<α, and e) H>θa>H/2.

Claim 37

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition disposed between the substrates, and voltage application means for applying voltages across the liquid crystal composition; said liquid crystal composition being placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic C phase, said temperature range including: a) a first temperature range where the liquid crystal composition shows a cone angle H in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle H in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ, d) δ<α, and e) H>θa>H/2.

Claim 38

A display apparatus according to claim 32, further including control means for controlling the voltage application means.

Claim 39

A liquid crystal composition, having: a temperature range of smectic A phase wherein the composition forms a plurality of first molecular layers each composed of plural liquid crystal molecules in smectic A phase, and also a temperature range of chiral smectic C phase wherein the composition forms a plurality of second molecular layers each composed of plural liquid crystal molecules in chiral smectic C phase, the second molecular layers being formed through deformation from the first molecular layers and showing a degree of deformation with respect to the first molecular layers which varies at different temperatures; said temperature range of chiral smectic C phase including a) a first temperature range where the second molecular layers show a degree of deformation which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the second molecular layers show a degree of deformation which decreases on further temperature decrease below the mediate temperature.

Claim 40

A liquid crystal composition, having: a temperature range of smectic A phase wherein the composition forms a plurality of first molecular layers each composed of plural liquid crystal molecules in smectic A phase, and also a temperature range of chiral smectic C phase wherein the composition forms a plurality of second molecular layers each composed of plural liquid crystal molecules in chiral smectic C phase, the second molecular layers being formed through deformation from the first molecular layers and showing a degree of deformation with respect to the first molecular layers which varies at different temperatures; said temperature range of chiral smectic C phase including a) a first temperature range where the second molecular layers show a degree of deformation which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the second molecular layers show a degree of deformation which decreases on further temperature decrease below the mediate temperature.

Claim 41

A liquid crystal composition according to claim 34, wherein the mediate temperature appears at a temperature of at least 10° C.

Claim 42

A liquid crystal composition according to claim 34, wherein the mediate temperature appears at a temperature of at least 25° C.

Claim 43

A liquid crystal composition according to claim 34, which further has a temperature range of cholesteric phase.

Claim 44

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in a temperature range of chiral smectic C phase and in an alignment state such that the liquid crystal molecules are aligned to form a plurality of molecular layers each composed of plural liquid crystal molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; said temperature range of chiral smectic C phase including: a) a first temperature range where the inclination angle δ increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ decreases on further temperature decrease below the mediate temperature.

Claim 45

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition disposed between the substrates and placed in a temperature range of chiral smectic C phase and in an alignment state such that the liquid crystal molecules are aligned to form a plurality of molecular layers each composed of plural liquid crystal molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; said temperature range of chiral smectic C phase including: a) a first temperature range where the inclination angle δ increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ decreases on further temperature decrease below the mediate temperature.

Claim 46

A device according to claim 38, wherein at least one of said pair of substrates is provided with a uniaxial alignment axis.

Claim 47

A device according to claim 39, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 48

A device according to claim 38, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which are parallel and the same as or opposite to each other.

Claim 49

A device according to claim 41, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 50

A device according to claim 38, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which intersect each other.

Claim 51

A device according to claim 43, wherein said respective directions intersect each other at an angle of 2-15 degrees.

Claim 52

A device according to claim 38, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 53

A device according to claim 38, wherein the medium temperature appears at a temperature of at least 10° C., and the liquid crystal composition also has a temperature range of smectic A phase and is placed in the chiral smectic C phase through cooling from the smectic A phase.

Claim 54

A device according to claim 38, wherein the medium temperature appears at a temperature of at least 25° C., and the liquid crystal composition also has a temperature range of smectic A phase and is placed in the chiral smectic C phase through cooling from the smectic A phase.

Claim 55

A device according to claim 38, wherein the liquid crystal composition also has temperature ranges of cholesteric phase and smectic A phase, respectively, and is placed in the chiral smectic C phase though cooling from the cholesteric phase and smectic A phase.

Claim 56

A liquid crystal device according to claim 38, wherein said liquid crystal composition in chiral smectic C phase has a maximum δ max of the inclination angle δ satisfying δ max ≦20 degrees and has been formed by cooling from smectic A phase.

Claim 57

A liquid crystal device according to claim 38, wherein said liquid crystal composition in chiral smectic C phase has a maximum δ max of the inclination angle δ satisfying δ max ≦15 degrees and has been formed by cooling from smectic A phase.

Claim 58

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition having a cone angle H, disposed between the substrates and placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic C phase, said temperature range including: a) a first temperature range where the inclination angle δ in chiral smectic C phase increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ in chiral smectic C phase decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ, d) δ<α, and e) H>θa>H/2.

Claim 59

A liquid crystal device, comprising: a pair of substrates, and a liquid crystal composition having a cone angle H, disposed between the substrates and placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic C phase, said temperature range including: a) a first temperature range where the inclination angle δ in chiral smectic C phase increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ in chiral smectic C phase decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ, d) δ<α, and e) H>θa>H/2.

Claim 60

A device according to claim 51, wherein at least one of said pair of substrates is provided with a uniaxial alignment axis.

Claim 61

A device according to claim 52, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 62

A device according to claim 51, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which are parallel and the same as or opposite to each other.

Claim 63

A device according to claim 54, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 64

A device according to claim 51, wherein said pair of substrates are respectively provided with a uniaxial alignment axis in respective directions which intersect each other.

Claim 65

A device according to claim 56, wherein said respective directions intersect each other at an angle of 2-15 degrees.

Claim 66

A device according to claim 57, wherein said uniaxial alignment axis has been provided by rubbing.

Claim 67

A device according to claim 51, wherein the medium temperature appears at a temperature of at least 10° C., and the liquid crystal composition also has a temperature range of smectic A phase and is placed in the chiral smectic C phase through cooling from the smectic A phase.

Claim 68

A device according to claim 51, wherein the medium temperature appears at a temperature of at least 25° C., and the liquid crystal composition also has a temperature range of smectic A phase and is placed in the chiral smectic C phase through cooling from the smectic A phase.

Claim 69

A device according to claim 51, wherein the liquid crystal composition also has temperature ranges of cholesteric phase and smectic A phase, respectively, and is placed in the chiral smectic C phase through cooling from the cholesteric phase and smectic A phase.

Claim 70

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition disposed between the substrates, voltage application means for applying voltages across the liquid crystal composition, said liquid crystal composition being placed in a temperature range of chiral smectic C phase and in an alignment state such that the liquid crystal molecules are aligned to form a plurality of molecular layers each composed of plural liquid crystal molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; said temperature range of chiral smectic C phase including: a) a first temperature range where the inclination angle δ increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ decreases on further temperature decrease below the mediate temperature.

Claim 71

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition disposed between the substrates, voltage application means for applying voltages across the liquid crystal composition, said liquid crystal composition being placed in a temperature range of chiral smectic C phase and in an alignment state such that the liquid crystal molecules are aligned to form a plurality of molecular layers each composed of plural liquid crystal molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; said temperature range of chiral smectic C phase including: a) a first temperature range where the inclination angle δ increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ decreases on further temperature decrease below the mediate temperature.

Claim 72

A display apparatus according to claim 62, further including control means for controlling the voltage application means.

Claim 73

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition having a cone angle H and disposed between the substrates, voltage application means for applying voltages across the liquid crystal composition, said liquid crystal composition being placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic phase, said temperature range including: a) a first temperature range where the inclination angle δ in chiral smectic C phase increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ in chiral smectic C phase decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ, d) δ<α, and e) H>θa>H/2.

Claim 74

A display apparatus, including: a liquid crystal device comprising a pair of substrates, and a liquid crystal composition having a cone angle H and disposed between the substrates, voltage application means for applying voltages across the liquid crystal composition, said liquid crystal composition being placed in an alignment state of chiral smectic C phase such that the liquid crystal molecules are oriented to any one of at least two optically stable states which form an angle 2θa therebetween (θa; tilt angle) in the absence of an electric field; the liquid crystal molecules are aligned to form a plurality of liquid crystal molecular layers of chiral smectic C phase each comprising a plurality of molecules and being inclined at an inclination angle δ with respect to a normal to the substrates; and the liquid crystal molecules are aligned at a pretilt angle α with respect to the substrates; wherein the liquid crystal composition has a temperature range where it assumes the chiral smectic phase, said temperature range including: a) a first temperature range where the inclination angle δ in chiral smectic C phase increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the inclination angle δ in chiral smectic C phase decreases on further temperature decrease below the mediate temperature; and the angles θa, H, δ and α satisfy the relationships of: c) H<α+δ, d) δ<α, and e) H>θa>H/2.

Claim 75

A display apparatus according to claim 64, further including control means for controlling the voltage application means.