What to look for when buying an overhead projector
Overhead Projector Product Selection Guide
used InFocus Systems Inc. PanelBook 450 LCD panel, $900 About 6 lb weight. It's passive matrix, but fine in a dim room. Boxlight Buhl 110 overhead projector, $300 is extra-powerful. 18 lb weight (includes bag and five $28 spare bulbs) Whole setup portable by one person.
3M discontinued LCD panels because LCD projectors are about the same price with better projection and many other reasons.