Reflection plate and liquid crystal display device

1. A reflection plate, including recessed or protruded parts and a reflection film formed over the recessed or protruded parts: wherein

a unit shape of the recessed or protruded parts is a polygon;

an arbitrary point other than a centroid of the polygon that constitutes the recessed or protrude part is placed at a position that meets with an orderly-mannered lattice point as an origin; and

each of the unit-shape polygons is arranged at a position that is rotated randomly with respect to the origin.

2. The reflection plate as claimed in claim 1 , wherein the orderly-mannered lattice is a closest-packed lattice or a tetragonal lattice.

3. The reflection plate as claimed in claim 1 , wherein the polygon is a square.

4. The reflection plate as claimed in claim 1 , wherein a size of one side of the polygon is in a range of about 3-20 μm.

5. The reflection plate as claimed in claim 1 , wherein a ratio of Dpi/Dsi is about 1.5-2.5, where Dsi is a size of one side of the polygon and Dpi is a distance between the lattice points of the orderly-mannered lattice.

6. The reflection plate as claimed in claim 1 , wherein an absolute value of a rotation angle of the unit shape is about 5 degrees or more.

7. The reflection plate as claimed in claim 1 , wherein, it is desirable for a ratio of Dpi/Dsi to be about 1.8-2.2, where Dsi is a size of one side of the polygon and Dpi is a distance between the lattice points of the orderly-mannered lattice.

8. The reflection plate as claimed in claim 1 , wherein, it is desirable for an absolute value of a rotation angle of the unit shape to be within a range of about 15-20 degrees.

9. The reflection plate as claimed in claim 1 , wherein the unit shape includes polygons of a same shape.

10. The reflection plate as claimed in claim 1 , wherein the unit shape includes polygons of two or more kinds of sizes or polygons of two or more kinds of shapes.

11. The reflection plate as claimed in claim 1 , wherein the neighboring unit shapes are not in contact with each other.

12. The reflection plate as claimed in claim 1 , wherein a part of the polygons is eliminated randomly.

13. The reflection plate as claimed in claim 1 , wherein the recessed or protruded part is in a substantially circular shape.

14. The reflection plate as claimed in claim 1 , wherein the reflection plate reflects light.

15. The reflection plate as claimed in claim 1 , wherein the reflection plate includes a photosensitive organic film and a reflection film.

16. The reflection plate as claimed in claim 15 , wherein the photosensitive organic film has a translucent characteristic.

17. The reflection plate as claimed in claim 15 , wherein the photosensitive organic film is a novolac resin or an acryl resin.

18. The reflection plate as claimed in claim 1 , wherein the recessed or protruded parts are formed by performing at least exposure and development in this order.

19. The reflection plate as claimed in claim 1 , wherein the recessed or protruded parts are formed into a substantially circular shape by overexposure.

20. A reflection plate including an uneven pattern, wherein, on conditions that: a unit shape is a closed figure formed by straight lines connecting between centers of lines that connect middle points of neighboring recessed parts or neighboring protruded parts, the closed figure surrounding the middle points; and there is assumed on the reflection plate an arbitrary orderly-mannered lattice including a lattice interval that is almost equal to an average value of the lines connecting between the middle points of the neighboring recessed parts or the neighboring protruded parts, there is a single lattice point of the orderly-mannered lattice within the unit shape.

21. A liquid crystal display device, including the reflection plate of claim 1 .