Retinal Projection Display

thingiverse

A retinal projection setup using Microvision SHOWWX laser picoprojectors requires safety measures, as the projector's maximum power is 200mW compared to HITLab's 2 μW. To ensure eye safety, a ND1024 neutral density filter is glued over the projector exit to reduce the output by 99.9%. Additionally, the beamsplitter reflects away 10% of light exiting the projector and 90% of reflected light from the concave mirror. The lowest brightness setting on the projector further ensures safety. The setup involves a laser scanner, beamsplitter, and spherical concave mirror to reduce the scanned image down to a point at the user's pupil. Mirrors are sourced from Anchor Optics' bargain bin for cost savings. However, the exit pupil width of around 1.5mm makes the system impractical for head-mounted use or any other way. Despite pausing work on the project, the author publishes it to help others and due to upcoming consumer see-through head-mounted displays.