Trans-reflecting type in plane switching mode liquid crystal display device having ferroelectric liquid crystal alignment layer

• US 20050140867A1
• Filed: 10/12/2004
• Published: 06/30/2005
• Est. Priority Date: 12/30/2003
• Status: Abandoned Application

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Choi, Su-Seok
• Application Number:
  US10/960,933
• Publication Number:
  US 20050140867A1
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133726 made of a mesogenic material
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/141 using ferroelectric liquid crystals

Abstract

Disclosed is a transreflective in-plane switching mode liquid crystal display (LCD) device. The LCD device includes first and second substrates including a plurality of pixels, each pixel having a transmitting unit and a reflecting unit, wherein the first substrate includes a first electrode and the second substrate includes a second electrode in each of the transmitting unit and the reflecting unit for applying voltages; first and second passive alignment layers over the first and second electrodes, respectively; first and second ferroelectric liquid crystal alignment layers on the first and second passive alignment layers, respectively; and a liquid crystal layer between the first and second substrates.

Claims

1. A liquid crystal display (LCD) device comprising:

first and second substrates including a plurality of pixels, each pixel having a transmitting unit and a reflecting unit, wherein the first substrate includes a first electrode and the second substrate includes a second electrode in each of the transmitting unit and the reflecting unit for applying voltages;

first and second passive alignment layers over the first and second electrodes, respectively;

first and second ferroelectric liquid crystal alignment layers on the first and second passive alignment layers, respectively; and

a liquid crystal layer between the first and second substrates.

2. The device of claim 1, wherein one of the first and second ferroelectric liquid crystal alignment layers includes an SSFLC-based ferroelectric liquid crystal.

3. The device of claim 2, wherein the SSFLC-based ferroelectric liquid crystal includes one of a CDR (Continuously Director Rotate)-based liquid crystal, an anti-ferroelectric liquid crystal, a ferroelectric liquid crystal monomer, a ferroelectric liquid crystal polymer, and a PS(Polymer Stabilization) ferroelectric liquid crystal.

4. The device of claim 1, wherein one of the first and second passive alignment layers includes polyimide.

5. The device of claim 1, wherein the liquid crystal layer includes a negative nematic liquid crystal.

6. The device of claim 1, wherein one of the first and second electrodes includes a transparent conductive material.

7. The device of claim 5, wherein the transparent conductive material includes Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO).

8. The device of claim 1, further comprising a reflector in the reflecting unit for reflecting light.

9. The device of claim 1, wherein a first voltage is applied to the transmitting unit and a second voltage is applied to the reflecting unit, the first voltage different from the second voltage.

10. The device of claim 9, wherein the first voltage is greater than the second voltage.

11. The device of claim 1, wherein molecules of the liquid crystal layer rotate when a voltage is applied between the first and second electrodes.

12. A liquid crystal display (LCD) device comprising:

a ferroelectric liquid crystal alignment layer between first and second substrates, the first and second substrates having a pixel, the pixel having a transmitting unit and a reflecting unit;

a liquid crystal layer between the first and second substrates;

first and second electrodes in the transmitting unit for applying a first voltage to the liquid crystal layer in the transmitting unit; and

third and fourth electrodes in the reflecting unit for applying a second voltage to the liquid crystal layer in the reflecting unit, the first voltage is different from the second voltage.

13. The device of claim 12, wherein the ferroelectric liquid crystal layer is photo-cured.

14. The device of claim 12, wherein the first voltage is greater than the second voltage.

15. A liquid crystal display (LCD) device comprising:

a substrate having first and second regions;

an alignment layer including ferroelectric liquid crystal molecules, the ferroelectric liquid crystal molecules rotating by a first angle θ

₁ in the first region, the ferroelectric liquid crystal molecules rotating by a second angle 02 in the second region, the first angle 0 different from the second angle 02; and

a liquid crystal layer contacting the ferroelectric liquid crystal molecules, liquid crystal molecules of the liquid crystal layer rotating according to the rotation of the ferroelectric liquid crystal molecules.

16. The device of claim 15, further comprising a reflector in the second region for reflecting light.

17. The device of claim 16, wherein the first angle is greater than the second angle (θ

₁>

θ

₂).

18. The device of claim 17, wherein a transmittance of the first region is substantially the same as that of the second region.

19. The device of claim 15, wherein the LCD device is an IPS (In Plane Switching) mode LCD.

20. The device of claim 15, wherein the liquid crystal molecules of the liquid crystal layer rotate on a plane.

21. The device of claim 15, wherein the alignment layer includes an SSFLC-based ferroelectric liquid crystal.

22. The device of claim 21, wherein the SSFLC-based ferroelectric liquid crystal includes one of a CDR (Continuously Director Rotate)-based liquid crystal, an anti-ferroelectric liquid crystal, a ferroelectric liquid crystal monomer, a ferroelectric liquid crystal polymer, and a PS(Polymer Stabilization) ferroelectric liquid crystal.