Liquid crystal display device and method of fabricating the same
A liquid crystal display device (LCD) and method of fabricating the same are provided, in which in an OCB mode LCD, an edge portion of a first electrode is formed with a taper angle of not less than approximately 25° and less than 90°, thus an electric field in the edge portion of the first electrode becomes nonuniform so that a transitional nucleus is easily created and liquid crystals are readily transitioned to a bend phase at a low transition voltage. As a result, the phase transition of the liquid crystals can be easily controlled.
1 . A liquid crystal display device comprising:
a first substrate;
a first electrode disposed on one surface of the first substrate and having tapered edges;
a first alignment layer disposed on the first electrode;
a second substrate opposite to and spaced apart from the first substrate;
a second electrode corresponding to the first electrode and disposed on one surface of the second substrate;
a second alignment layer disposed on the second electrode; and
a liquid crystal layer disposed between the first and second substrates.
2 . The device according to claim 1 , wherein each of the tapered edges has an angle of not less than approximately 25° and less than 90°.
3 . The device according to claim 1 , further comprising a metal interconnection and an insulating layer interposed between the first substrate and the first electrode.
4 . The device according to claim 3 , wherein the metal interconnection is a data line.
5 . The device according to claim 3 , wherein a distance between the metal interconnection and the first electrode is at least 1 μm to 5 μm.
6 . The device according to claim 1 , wherein the first electrode is formed of a transparent conductive insulating material.
7 . The device according to claim 6 , wherein the transparent conductive insulating material is indium tin oxide (ITO) or indium zinc oxide (IZO).
8 . The device according to claim 1 , wherein the first electrode has a thickness of approximately 1000 Å to approximately 3000 Å.
9 . The device according to claim 1 , wherein the first and second alignment layers are rubbed in a same direction.
10 . The device according to claim 1 , wherein each of the first and second alignment layers has a pretilt angle of approximately 5° to approximately 20°.
11 . The device according to claim 1 , wherein each of the first and second alignment layers has a thickness of approximately 500 Å to approximately 1000 Å.
12 . The device according to claim 1 , further comprising:
a first polarizer disposed on an other surface of the first substrate; and
a second polarizer disposed on an other surface of the second substrate.
13 . The device according to claim 12 , further comprising a biaxial compensation film interposed between the second substrate and the second polarizer.
14 . The device according to claim 12 , wherein the first and second polarizers have polarization axes that cross each other
15 . The device according to claim 1 , wherein the liquid crystal layer has a thickness of about 1.5 to 2.5 μm.
16 . The device according to claim 1 , wherein the liquid crystal layer includes liquid crystals with positive dielectric anisotropy.
17 . The device according to claim 1 , further comprising a backlight unit disposed under the first substrate.
18 . The device according to claim 17 , wherein the backlight unit includes a reflector sheet, a diffuser sheet, and a light emitting diode (LED).
19 . The device according to claim 18 , wherein the LED includes at least one group selected from a group consisting of red (R), green (G), and blue (B) LEDs and a group consisting of cyan (C), magenta (M), and yellow (Y) LEDs.
20 . The device according to claim 18 , wherein the LED is a white LED.
21 . The device according to claim 1 , further comprising a color filter interposed between the second electrode and the second substrate.
22 . The device according to claim 1 , wherein the liquid crystal layer includes optically compensated bend (OCB) mode liquid crystals.
23 . The device according to claim 1 , wherein the insulating layer is a planarization layer.
24 . A method of fabricating a liquid crystal display device, comprising:
preparing a first substrate and a second substrate;
forming a metal interconnection on one surface of the first substrate;
forming an insulating layer on the first substrate on which the metal interconnection is formed;
forming a first electrode on the insulating layer, the first electrode having a tapered edge with an angle of not less than approximately 25° and less than 90°;
forming a first alignment layer on the first electrode;
forming a second electrode on one surface of the second substrate;
forming a second alignment layer on the second electrode; and
placing a liquid crystal layer between the first and second substrates and encapsulating the first and second substrates.
25 . The method according to claim 24 , wherein forming the metal interconnection comprises forming at least one selected from a group consisting of a scan line, a data line, and a common line.
26 . The method according to claim 24 , wherein forming the insulating layer comprises forming a planarization layer.
27 . The method according to claim 24 , further comprising rubbing the first and second alignment layers in a same direction after forming the first and second alignment layers.
28 . The method according to claim 24 , wherein encapsulating the first and second substrates comprises encapsulating the first and second substrates such that the first and second substrates have a gap of approximately 1.5 μm to approximately 2.5 μm.