Tiled retroreflector with multi-stage dicing
Methods of making tiled articles and molds used to make retroreflective articles. The methods include forming a prism array on a master substrate and forming a replica of the master. A reference edge is formed on the replica, thereby reducing the size of the prism array, yet maintaining a lateral dimension of the replica to maintain ease of handling of the replica. The replica is copied and the reference edge on the copied tiles are exposed, such that the reference edge can be mated and secured face-to-face with a reference edge on other tiles in order to form a tiled article. The tiled article is used as a mold to produce retroreflective articles or can be further duplicated and mated to form larger tiled articles to be used as molds. Tiled articles used as molds and retroreflective articles produced from the molds are also disclosed.
1. A method of making a tiled article, the method comprising:
providing a tile including a top surface comprising prism elements;
forming a wall on the tile by removing a portion of the top surface of the tile, wherein the wall shares a first common edge with the top surface of the tile;
forming replicas of the tile;
forming a face on each replica, wherein the face shares a second common edge with the wall on each replica, and a first common edge of each replica is on an opposite side of the wall from the second common edge,
wherein each replica includes a bottom surface on an opposite side from the top surface; and
wherein forming the face on each replica thereby forms a third common edge, the third common edge being shared between the face and the bottom surface, the third common edge being on an opposite side of the face from the second common edge; and
positioning the replicas such that a wall on each replica is face-to-face with, and directly abuts a wall on an adjacent replica to thereby form a tiled article.
2. The method according to claim 1 , wherein the tile comprises one of:
a. a master comprising a substrate including prism elements on a top surface thereof;
b. a replica of a master, the master comprising a substrate including prism elements on a top surface thereof.
3. The method according to claim 1 , wherein the tile comprises one of:
a. a single-piece tile, or
b. a plurality of joined tiles.
4. The method according to claim 3 , wherein the tile is a plurality of tiles and one of the following is satisfied:
a. prism elements are the same between the plurality of tiles, or
b. prism elements are different between the plurality of tiles.
5. The method according to claim 1 , wherein an angle between the wall and the top surface is about 90° as measured through the tile.
6. The method according to claim 1 , wherein a height of the wall is greater than a height of the prism elements.
7. The method according to claim 1 , wherein the wall is formed by making a depression in the tile.
8. The method according to claim 1 , wherein making the depression includes removing at least a portion of the prism elements.
9. The method according to claim 1 , wherein making the depression does not substantially reduce a lateral dimension of the tile as measured through a part of the tile that is opposite to the top surface.
10. The method according to claim 1 , wherein the wall is formed by diamond cutting.
11. The method according to claim 1 , wherein the face is formed on each replica by removing a portion of each replica.
12. The method according to claim 11 , wherein removing a portion of each replica includes removing a portion of the wall on each replica.
13. The method according to claim 1 , wherein an angle between the wall and the face on each replica is less than 180° as measured through the replica.
14. The method according to claim 11 , wherein removing a portion from each replica is accomplished by wire electrical discharge cutting, laser cutting, water jet cutting, waterjet-guided laser cutting, or a combination thereof.
15. The method according to claim 1 , wherein:
the wall on the tile comprises a plurality of walls; and
the prism elements on the tile is bounded by the plurality of walls.
16. The method according to claim 15 , wherein each wall on the tile shares a common interface with adjacent walls on the tile, and adjacent walls on the tile have different heights.
17. The method according to claim 1 , wherein:
the prism elements have a prism orientation; and
the replicas are positioned such that the prism elements on adjacent replicas have prism orientations that are offset by about 15° to about 180°.