An Open Proposal for Innovation, Part Two: Projector Math

The previous article identified some of the challenges to maintaining a large number of high-tech classrooms constructed with traditional presentation technology, namely that the exorbitant cost of upkeep transforms great classrooms into "fiscal alligators" that ravage funding pools. Let's take a closer look at one big-ticket item: the display system.

A few assumptions

1. Until digital wallpaper is perfected, there is no getting around the need for a projected image in a classroom or conference room with more than twenty seats or so.
2. Integral to learning (and dominating every aspect of our lives), the big-picture genie cannot be put back into the bottle. In the near future, expect to find large digital displays everywhere.
3. For text to be readable, the height of a projected image must be at least one-sixth the distance to the farthest viewer (one-fifth is even better). No one takes binoculars to class unless they're on a bird watching field trip.
4. For any image to be easily readable, it must offer sufficient contrast (black text on white background) and color clarity. A bright projector (greater than 3500 ANSI lumens) is needed. No one ever complains that the projected image is too bright. No one should have to dim the lights while teaching unless they're teaching 20th-Century photo processing.
5. It is unclear whether flat panels offer greater practical longevity than projectors, despite manufacturers' claims to the contrary. Let's play it safe and assume they also have a useful life of about four or five years.
6. DVI is not going to solve all our problems. 99.9% of the classroom systems currently in place utilize analog video processing. Most laptops in service still have VGA (analog) video outputs. Hoping to solve a plumbing compatibility problem withyet more plumbing seems counter-intuitive and costly.