Surface light source, method of driving the same, and backlight unit having the same

1. A surface light source comprising:

a plate type light source body having a sealed discharging space formed therein;

a plate type electrode unit comprising a first surface electrode on or adjacent a first outer major surface of the light source body, and a second surface electrode on or adjacent a second outer major surface of the light source body, wherein each of the first surface electrode and the second surface electrode is electrically partitioned into a plurality of regions such that at least one of the plurality of regions of the first surface electrode is partitioned in a first direction and at least one of the plurality of regions of the second surface electrode is partitioned in a second direction different from the first direction; and

a multiple voltage applying unit operable to apply voltages differently to each of the plurality of regions, so as to independently vary a brightness of the light emitted by each of the plurality of regions.

2. The surface light source of claim 1 , wherein the electrode unit comprises electrode patterns spaced apart from each other.

3. The surface light source of claim 1 , wherein the light source body comprises:

a plate type first substrate;

a plate type second substrate separated from the first substrate by a predetermined distance; and

a sealing member formed on edges between the first and second substrates to seal an inner space between the first and second substrates.

4. The surface light source of claim 3 , further comprising at least one spacer inserted between the first and second substrates.

5. The surface light source of claim 1 , wherein the electrode unit comprises:

a base layer;

an electrode pattern joined to an upper side of the base layer; and

a protective layer overlying an upper side of the electrode pattern and the base layer.

6. The surface light source of claim 5 , wherein the base layer and the protective layer have a property of transmitting visible rays therethrough.

7. The surface light source of claim 5 , wherein the electrode pattern comprises a circular pattern, an oval pattern, a regular polygonal pattern, a net-structured pattern, or a stripe type pattern.

8. The surface light source of claim 5 , wherein the electrode pattern is made of one selected from copper, silver, gold, aluminum, ITO, nickel, chrome, carbon-based conductive material, conductive polymer, and a mixture thereof.

9. The surface light source of claim 1 , wherein the electrode unit has an open ratio that is equal to or higher than 60%, the open ratio defined as a ratio of an area of one of the first or the second outer major surfaces that is not taken up by the respective surface electrode relative to a total area of the respective outer major surface.

10. The surface light source of claim 1 , wherein a mercury excluded discharging gas is injected into the light source body.

11. A method of operating a surface light source comprising:

applying voltages differently to each of a plurality of partitioned regions of a plate type electrode unit having a property of transmitting visible rays therethrough on a plate type light source body having a sealed discharging space, the plate type electrode unit including a first surface electrode on or adjacent a first outer major surface of the light source body, and a second surface electrode on or adjacent a second outer major surface of the light source body, wherein each of the first surface electrode and the second surface electrode is electrically partitioned into a plurality of regions such that at least one of the plurality of regions of the first surface electrode is partitioned in a first direction and at least one of the plurality of regions of the second surface electrode is partitioned in a second direction different from the first direction;

wherein the applying voltages differently to each of the plurality of regions is performed so as to independently vary a brightness of the light emitted by each of the plurality of regions.

12. The method of claim 11 , wherein the voltages are applied to the respective regions in accordance with a control signal associated with screen information of a liquid crystal display.

13. A backlight unit comprising:

a surface light source comprising:

a plate type light source body having a sealed discharging space formed therein;

a plate type electrode unit comprising a first surface electrode on or adjacent a first outer major surface of the light source body, and a second surface electrode on or adjacent a second outer major surface of the light source body, wherein each of the first surface electrode and the second surface electrode is electrically partitioned into a plurality of regions such that at least one of the plurality of regions of the first surface electrode is partitioned in a first direction and at least one of the plurality of regions of the second surface electrode is partitioned in a second direction different from the first direction; and

a multiple voltage applying unit operable to apply voltages differently to each of the plurality of regions, so as to independently vary a brightness of the light emitted by each of the plurality of regions; and

a case accommodating the surface light source.

14. The backlight unit of claim 13 , wherein the multiple voltage applying unit includes an inverter, operable to apply voltages independently to each of the first and second surface electrodes.

15. The backlight unit of claim 13 , further comprising an electrode data controller to differently control voltages applied to the respective regions by the multiple voltage applying unit.

16. The surface light source of claim 1 , wherein the first surface electrode and the second surface electrode are electrically partitioned in perpendicular directions to each other.