Light Extraction Pattern Printing

Example 4

FIG. 24 shows an annotated photograph of an ordered light extraction pattern of semi-opaque microdots printed on a broad-area surface (exemplifying surface 11) of a planar acrylic sheet (exemplifying light guiding sheet 10). Each of the printed microdots forms a discrete light extraction feature on the surface (exemplifying individual light extraction feature 8). The light extraction pattern was printed using a semi-opaque UV-curable white ink containing TiO₂ particles in concentrations from 5% to 15% by weight. The printed pattern had a fixed pitch in both X and Y directions and included microdots of different sizes. At least some of the larger light extraction features 8 were formed by individual microdrops each having a volume of around 40,000 cubic micrometers.

Example 5

FIG. 25 shows an annotated photograph exemplifying a random pattern of light extraction features 8 printed using the same type of ink and printing hardware as in the Example 4. The resulting printed pattern of FIG. 25 included a random mix of different shapes (including regular, quasi-regular, round, elongated, irregular and highly irregular shapes), orientation and sizes.