Liquid crystal display device comprising a black matrix including carbon particles coated with an insulating material, metallic titanium particles, and a color pigment
View Patent ↗Disclosed is a black matrix for a liquid crystal display device (LCD) having an impedance about equal to or more than 10 5 Ω, a specific resistance about equal to or more than 10 11 Ωcm, and a relative dielectric constant about equal to or less than 20 at a driving frequency of about 1 kHz to 100 kHz. The black matrix as disclosed has dielectric properties that minimize parasitic capacitance between the black matrix and the circuitry of the LCD, thereby preventing a signal delay in charging pixel electrodes that degrades the LCD image.
1. A liquid crystal display device, comprising:
a first substrate;
a second substrate substantially parallel to the first substrate;
a plurality of gate and data lines crossing each other on the first substrate and defining a pixel region;
a thin film transistor near a crossing portion of the gate and data lines;
a color filter pattern corresponding to the pixel region;
a pixel electrode corresponding to the pixel region; and
a black matrix disposed on the thin film transistor and including carbon particles coated with an insulating material and metallic titanium particles, the black matrix having an impedance equal to about 10 5 Ω or more, a specific resistance equal to about 10 11 Ωcm or more, and a relative dielectric constant equal to about 20 or less at a driving frequency between about 1 kHz and 100 kHz, wherein the black matrix includes a color pigment, and wherein the black matrix further includes at least one of bromine (Br) and chlorine (Cl).
2. The device according to claim 1 , wherein the color pigment includes red, green, blue, violet and yellow pigments.
3. The device according to claim 1 , wherein the color pigment includes at least three of red, green, blue, violet and yellow pigments.
4. The device according to claim 1 , wherein the black matrix further includes a solvent.
5. The device according to claim 4 , wherein the solvent includes propylene glycol monomethyl ether acetate (PGMEA).
6. The device according to claim 1 , wherein the black matrix has a minimum thickness equal to about 2 μm.
7. The device according to claim 1 , wherein the pixel electrode is disposed on the color filter pattern, and the pixel electrode and the color filter pattern overlap the gate line.
8. The device according to claim 1 , wherein the black matrix is disposed on the plurality of gate lines and data lines.