UBC Theses and Dissertations
Integration and application of microlens arrays within heads-up display Yan, Weicheng
Heads-up display technology is a subject of growing interest for virtual reality and augmented reality systems. The proposed work recognizes this interest and targets a key challenge for integrating this technology within eyewear, in that such systems must enable tight imaging while having a flat form factor. A Gabor lens, being coupled plano-concave and plano-convex microlens arrays, is developed in this work to meet this challenge. In the first stage of the work, the MLAs are designed with three design criteria. For Criterion I, the coupled MLAs must project an image of the microdisplay into the relaxed eye at infinity with an angular field-of-view between 15° and 25°. For Criterion II, the coupled MLAs must project a clear image of the microdisplay with a resolution of 30 cycles-per-mm or greater. For Criterion III, the coupled MLAs must be implemented with a flat form factor to enable integration within contemporary eyewear by having a thickness of less than 23.4 mm. In the second stage of the work, the optimized design for the MLAs is realized by the development and implementation of a specialized fabrication process. The process applies a tunable plasma pre-treatment to a glass substrate followed by dispensing, curing, and casting of microlenses on the substrate to realize arrays with the necessary diameters and radii of curvature. The plano-concave and plano-convex MLAs are then fabricated and coupled to form the Gabor lens, which is packaged with a baffle and microdisplay to function as the heads-up display. In the third and final stage of the work, the developed heads-up display undergoes performance testing to define its modulation transfer function (MTF). The measured MTF results are compared to those of the ray-based simulations and strong agreement is seen. Moreover, it is found that the developed heads-up display has an FOVA of 18.2°, a resolution of 30 cycles/mm, and a net length of 11.4 mm, and thus it meets the above design criteria. Ultimately, the developed heads-up display can enable the tight imaging and flat form factor that are being sought for future virtual reality and augmented reality systems.
Item Citations and Data
Attribution-NonCommercial-NoDerivatives 4.0 International