Liquid crystal display device

1. A liquid crystal display (LCD) comprising:

a first substrate on which a thin film transistor (TFT) and a color filter are formed;

a second substrate spaced apart from the first substrate by a predetermined distance; a liquid crystal layer interposed between the first and second substrates;

a first polarizer attached over a lower surface of the first substrate, for changing light into linearly polarized light;

a second polarizer attached over an upper surface of the second substrate, the second polarizer having a transmission axis perpendicular to that of the first polarizer; and a third polarizer formed between the first substrate and the liquid crystal layer,

wherein a transmission axis of the third polarizer coincides with that of the first polarizer.

2. The LCD according to claim 1 , wherein the first substrate has the color filter on TFT (COT) structure in which the color filter is formed after the TFT is formed.

3. The LCD according to claim 1 , wherein the first substrate has the TFT on color filter (TOC) structure in which the TFT is formed after the color filter is formed.

4. The LCD according to claim 1 , wherein the third polarizer polarizes non-polarized light that has been scattered by the TFT and the color filter formed on the first substrate.

5. The LCD according to claim 1 , wherein the third polarizer is coated over the first substrate.

6. A liquid crystal display (LCD) comprising:

a first substrate on which a thin film transistor (TFT) and a color filter are formed;

a second substrate spaced apart from the first substrate by a predetermined distance;

a liquid crystal layer interposed between the first and second substrates;

a first polarizer attached over a lower surface of the first substrate, for changing light into linearly polarized light;

a second polarizer attached over an upper surface of the second substrate, the second polarizer having a transmission axis perpendicular to the first polarizer;

a third polarizer formed between the first substrate and the liquid crystal layer and having a transmission axis whose direction is the same as the first polarizer; and

a backlight unit provided at a lower portion of the first substrate, for supplying light.

7. The LCD according to claim 6 , wherein the first substrate has a the color filter on TFT (COT) structure in which the color filter is formed after the TFT is formed.

8. The LCD according to claim 6 , wherein the first substrate has the TFT on color filter (TOC) structure in which the TFT is formed after the color filter is formed.

9. The LCD according to claim 6 , wherein the third polarizer polarizes non-polarized light that has passed through the TFT and the color filter formed on the first substrate.

10. The LCD according to claim 7 , wherein the TFT comprises a gate electrode, an insulating layer, an active layer, an ohmic contact layer, and source/drain electrodes, which are sequentially formed over the first substrate.

11. The LCD according to claim 10 , further comprising:

a passivation layer formed over an upper portion of the TFT;

a color filter layer having first to third colored layers formed at each pixel over the passivation layer, the first to third colored layers being spaced apart from one another by a predetermined distance;

a black matrix formed at gaps defined by the first to third colored layers;

an overcoat layer formed over the black matrix; and

a pixel electrode formed on the overcoat layer.

12. The LCD according to claim 11 , wherein the pixel electrode is electrically connected with the drain electrode of the TFT through a contact hole formed in a part of the color filter layer and the overcoat layer.

13. The LCD according to claim 11 , wherein the third polarizer is coated over the pixel electrode.