Abstract
A new method for producing gapless biaxial microlens array is proposed for a dual-directional light-control film with a high fill factor. Three steps in this production technique are included for formations of semiellipsoid microlens array with low fill factor to be caulked into gapless biaxial microlens array mold inserts. First, two photoresists with different melting temperatures method will be used to obtain the semiellipsoid microlens array with low fill factor. Second, the air-pressure electroforming caulking is applied to fill the gaps between adjacent lenses after the thermal reflow. Third, the secondary master mold of gapless biaxial microlens array is fabricated for hot embossing process to replicate the array pattern onto PMMA sheet. A gapless biaxial microlens array with long and short axes is developed to change the vertical and horizontal light emitting angles. Based on the simulated and experimental results, the horizontal light emitting angle can be increased to 30° and the vertical one is reduced to 15° by using the biaxial microlens array with high fill factor as the optical scattering film, to effectively enhance optical uniformity for the application of a rear projection display.
