Multi plasma display device

1. A multi plasma display device comprising:

a first panel;

a second panel positioned adjacent to the first panel; and

a lens unit positioned so that the lens unit commonly overlaps a portion of a front surface of the first panel and a portion of a front surface of the second panel in a boundary portion between the first panel and the second panel,

wherein each of the first panel and the second panel includes:

a front substrate;

a rear substrate positioned opposite the front substrate;

a barrier rib that is positioned between the front substrate and the rear substrate to partition a discharge cell; and

a seal layer between the front substrate and the rear substrate,

wherein the lens unit overlaps the seal layer of the first panel and the seal layer of the second panel and does not overlap the discharge cell of the first panel and the discharge cell of the second panel.

2. The multi plasma display device of claim 1 , wherein the lens unit allows a size of the boundary portion between the first and second panels to seem to be smaller than an actual size of the boundary portion through an optical operation of the lens unit.

3. The multi plasma display device of claim 1 , wherein one end of the lens unit is positioned between the seal layer and an outermost barrier rib of the first panel, and the other end is positioned between the seal layer and an outermost barrier rib of the second panel.

4. The multi plasma display device of claim 1 , wherein one end of the lens unit is positioned in a portion overlapping an outermost barrier rib of the first panel, and the other end is positioned in a portion overlapping an outermost barrier rib of the second panel.

5. The multi plasma display device of claim 1 , wherein the lens unit includes a plurality of protrusions on the surface of the lens unit.

6. The multi plasma display device of claim 5 , wherein each of the plurality of protrusions has substantially a triangle shape.

7. The multi plasma display device of claim 5 , wherein the lens unit includes a first portion overlapping the first panel and a second portion overlapping the second panel,

wherein a shape of each of the protrusions formed in the first portion is different from a shape of each of the protrusions formed in the second portion.

8. The multi plasma display device of claim 1 , wherein a width of the lens unit is greater than the size of the boundary portion.

9. The multi plasma display device of claim 1 , wherein the lens unit includes a plurality of first prisms in a first portion overlapping the first panel and a plurality of second prisms in a second portion overlapping the second panel,

wherein an angle between a first surface of the second prism adjacent to the first portion and a base of the lens unit is less than an angle between a second surface of the second prism opposite the first surface and the base of the lens unit,

wherein an angle between a first surface of the first prism adjacent to the second portion and the base of the lens unit is less than an angle between a second surface of the first prism opposite the first surface and the base of the lens unit.

10. The multi plasma display device of claim 9 , wherein a distance between a top of an outermost first prism of the first prisms and a top of an outermost second prism of the second prisms is greater than a distance between tops of two adjacent first prisms of the first prisms and a distance between tops of two adjacent second prisms of the second prisms in a boundary portion between the first portion and the second portion.

11. The multi plasma display device of claim 9 , wherein the first prisms and the second prisms are arranged in opposite directions.

12. The multi plasma display device of claim 1 , further comprising a black layer positioned in the boundary portion between the first panel and the second panel.

13. The multi plasma display device of claim 12 , wherein the black layer is positioned at the side of at least one of the first panel and the second panel.

14. The multi plasma display device of claim 1 , wherein a width of the lens unit is greater than a thickness of the lens unit,

wherein a ratio of the width to the thickness of the lens unit is 10:1 to 10:8.

15. The multi plasma display device of claim 14 , wherein the ratio of the width to the thickness of the lens unit is 10:2 to 10:6.