Automotive augmented reality 3D head-up display based on light-field rendering with eye-tracking.

We explore the feasibility of implementing stereoscopy-based 3D images with an eye-tracking-based light-field display and actual head-up display optics for automotive applications. We translate the driver's eye position into the virtual eyebox plane via a "light-weight" equation to replace the actual optics with an effective lens model, and we implement a light-field rendering algorithm using the model-processed eye-tracking data. Furthermore, our experimental results with a prototype closely match our ray-tracing simulations in terms of designed viewing conditions and low-crosstalk margin width. The prototype successfully delivers virtual images with a field of view of 10° × 5° and static crosstalk of <1.5%.

Angle-selective optical filter for highly sensitive reflection photoplethysmogram.

We report an angle-selective optical filter (ASOF) for highly sensitive reflection photoplethysmography (PPG) sensors. The ASOF features slanted aluminum (Al) micromirror arrays embedded in transparent polymer resin, which effectively block scattered light under human tissue. The device microfabrication was done by using geometry-guided resist reflow of polymer micropatterns, polydimethylsiloxane replica molding, and oblique angle deposition of thin Al film. The angular transmittance through the ASOF is precisely controlled by the angle of micromirrors. For the mirror angle of 30 degrees, the ASOF accepts an incident light between - 90 to + 50 degrees and the maximum transmittance at - 55 degrees. The ASOF exhibits the substantial reduction of both the in-band noise of PPG signals over a factor of two and the low-frequency noise by three times. Consequently, this filter allows distinguishing the diastolic peak that allows miscellaneous parameters with diverse vascular information. This optical filter provides a new opportunity for highly sensitive PPG monitoring or miscellaneous optical tomography.