The Tanaka Auto Door opens automatically when you stand in front of it. Even better, it only opens just enough to let the individual person come in.
The Auto Door consists of individual slats that slide open and closed from the side of the door. Each slat is half the width of the door; each slat has a sensor. If you stand in front of the door, the sensors determine how much of the door needs to open to allow you to enter.
(From Tanaka Auto Door)
Everyone is of course familiar with the well-known automatic doors from the Enterprise from the original Star Trek. During the filming of the original series in the mid-1960's, an investor saw the door appear to jump open when William Shatner approached it. Excited, he offered a million dollars for the secret - which turned out to be two stage hands, one on either side of the doorway.
There are earlier references in science fiction to automatic doors. In his 1889 novella In the Year 2889, Jules Verne writes about an automatic door:
The two men addressed turned obediently, after one reluctant glance at Graham, and instead of going through the archway as he expected, walked straight to the dead wall of the apartment opposite the archway. And then came a strange thing; a long strip of this apparently solid wall rolled up with a snap, hung over the two retreating men and fell again, and immediately Graham was alone with the new comer and the purple-robed man with the flaxen beard. (Read more about Verne's automatic door.)
You may be wondering what is so great about a door that opens only just enough to let a person come in or out; it minimizes the amount of heating or air conditioning let out of a building, as well as minimizing the entry of pollen or other pollutants from the outside.
Science fiction door afficionados may also want to check out the Sirius Cybernetics Self-Satisfied Door from The Hitchhiker's Guide to the Galaxy; see the Tanaka Auto Door demo.
(This Science Fiction in the News story used with permission from Technovelgy.com - where science meets fiction.)
