Performances of Fine-Pitch Lenticular Lens Arrays Fabricated Using Semi-Cylindrical Resist Patterns

Abstract

Utilizing semi-cylindrical patterns of negative resist SU-8, lenticular lens arrays with a fine lens pitch of 100 µm were fabricated. The patterns were formed on 240-µm thick quartz plates coated with 100-µm thick SU-8 by the defocused projection exposure using a normal reticle with 50-µm line-and-space (L&S) patterns. Because the SU-8 was almost transparent for visible light with wavelengths longer than 400 nm, the patterns were directly used as lenticular lens arrays as they were. Next, a lenticular lens array set was assembled by placing a quartz plate with the lens patterns on an apple picture covered with a film reticle of 50-µm L&S patterns. When the set was observed with great interest, two scenes of an apple and all black were successfully switched alternately. Because the lens pitch of 100 µm was considerably smaller than the conventional one of 254 µm, smoothness of the picture edge was notably improved especially at inclined parts of the pictures. However, the angle for switching the two scenes was as small as approximately 6º. It was discussed that the small angle switching was caused by the substantial thickness of the lens array set including thicknesses of the quartz plate and the reticle film, and the angle might be controllable by decreasing the thickness.

Two-layer resist process for printing thick patterns by exploiting a maskless projection exposure system using a liquid-crystal-display panel

“…However, in recent 20 years, lithography has gradually become to be used for printing large patterns with 10-100 μm sizes. Typical application targets are fluidic devices, [1][2][3][4][5][6][7][8][9][10] lens arrays, [11][12][13][14][15][16][17] bio-chips, [18][19][20][21][22][23] molds for electroplating metals, [24][25][26] and others. In these cases, because only small numbers of products are required generally, high-cost lithography systems for the use of semiconductor or MEMS devices cannot be adopted.…”