Liquid crystal display using ferroelectric liquid crystal, and fabrication method thereof

1. A liquid crystal display comprising:

a first substrate;

a first alignment layer over the first substrate;

a first ferroelectric liquid crystal layer over the first alignment layer, and having a polarity in a first direction;

a second substrate facing the first substrate;

a second alignment layer over the second substrate;

a second ferroelectric liquid crystal layer over the second alignment layer, and having a polarity of the same first direction as the first ferroelectric liquid crystal layer; and

a third liquid crystal layer formed between the first ferroelectric liquid crystal layer and the second ferroelectric liquid crystal layer,

wherein the third liquid crystal layer has a phase transition from a nematic phase to an isotropic phase when the temperature is raised.

2. The display according to claim 1 , wherein the first substrate has a pixel electrode, and the second substrate has a common electrode.

3. The display according to claim 1 , wherein the first and second ferroelectric liquid crystal layers have a phase transition from a chiral smectic C (SmC*) phase to a chiral nematic (N*) phase when a temperature is raised.

4. The display according to claim 1 , wherein the first and second ferroelectric liquid crystal layers have a phase transition from a chiral smectic C (SmC*) phase to a smectic A (SmA) phase when a temperature is raised.

5. The display according to claim 1 , wherein the third liquid crystal layer is formed of bulk nematic liquid crystal.

6. The display according to claim 1 , wherein the first and second ferroelectric liquid crystal layers have chiral smectic C (SmC*) phases at a temperature of T 1 at which the third liquid crystal layer has a phase transition from a chiral nematic (N*) phase to an isotropic phase.

7. The display according to claim 6 , wherein the first and second ferroelectric liquid crystal layers have a phase transition from the chiral smectic C (SmC*) phase to a chiral nematic (N*) phase at a temperature T 2 higher than the temperature of T 1 .

8. The display according to claim 6 , wherein the first and second ferroelectric liquid crystal layers have a phase transition from the chiral smectic C (SmC*) phase to a smectic A (SmA) phase at a temperature T 2 higher than the temperature of T 1 .

9. A method for fabricating a liquid crystal display, the method comprising:

forming first and second alignment layers over first and second substrates, respectively;

forming first and second ferroelectric liquid crystal layers over the first and second alignment layers, respectively;

filling a third liquid crystal layer between the first and second substrates to form a liquid crystal panel;

heating the liquid crystal panel to a temperature T 1 to cause a phase transition of the first and second ferroelectric liquid crystal layers to nematic liquid crystal layers having a chiral nematic (N*) phase and to also cause a phase transition of the third liquid crystal layer to an isotropic liquid crystal layer;

cooling the liquid crystal panel to a temperature of T 2 and applying a direct current voltage to the liquid crystal panel, to cause a phase transition of the first and second ferroelectric liquid crystal layers from the chiral nematic (N*) phase to a chiral smectic C (SmC*) phase and maintain the third liquid crystal layer in an isotropic phase; and

cooling the liquid crystal panel to a temperature T 3 , to maintain the first and second ferroelectric liquid crystal layers in the chiral smectic C (SmC*) phase and to cause a phase transition of the third liquid crystal layer from the isotropic phase to the chiral nematic (N*) phase.

10. The method according to claim 9 , wherein when the liquid crystal panel is cooled to the temperature T 2 and has a direct current voltage applied thereto, the applied direct current voltage up to 10 volts.

11. The method according to claim 9 , wherein the first substrate has a pixel electrode, and the second substrate has a common electrode.

12. The method according to claim 9 , wherein when the liquid crystal panel is cooled to the temperature of T 2 and has a direct current voltage applied thereto, the first and second ferroelectric liquid crystal layers have polarities in the same direction.

13. A method for fabricating a liquid crystal display, the method comprising:

forming first and second alignment layers over first and second substrates, respectively;

forming first and second ferroelectric liquid crystal layers over the first and second alignment layers, respectively;

filling a third liquid crystal layer between the first and second substrates to form a liquid crystal panel;

heating the liquid crystal panel at a predetermined temperature of T 1 to cause a phase transition of the first and second ferroelectric liquid crystal layers to smectic A (SmA) phase liquid crystal layers and cause a phase transition of the third liquid crystal layer to an isotropic liquid crystal layer;

cooling the liquid crystal panel to a temperature T 2 and applying a direct current voltage to the liquid crystal panel, to cause a phase transition of the first and second ferroelectric liquid crystal layers from the smectic A (SmA) phase to a chiral smectic C (SmC*) phase and maintaining the third liquid crystal layer in an isotropic phase; and

cooling the liquid crystal panel to a temperature of T 3 , to maintain the first and second ferroelectric liquid crystal layers in the chiral smectic C (SmC*) phase and cause a phase transition of the third liquid crystal layer from the isotropic phase to a chiral nematic (N*) phase.

14. The method according to claim 13 , wherein when the liquid crystal panel is cooled to the temperature of T 2 and has the direct current voltage applied thereto, the applied direct current voltage is up to 10 volts.

15. The method according to claim 13 , wherein the first substrate has a pixel electrode, and the second substrate has a common electrode.

16. The method according to claim 14 , wherein when the liquid crystal panel is cooled to the temperature T 2 and has a direct current voltage applied thereto, the first and second ferroelectric liquid crystal layers have polarities in the same direction.