We present the optical implementation of the board game "black box" using
a laser, fluorescence and smoke

Haist, Tobias

Knoll, Ralf

Lorenz, Andreas

OPUS Online Publikationen der Universität Stuttgart

1Black Box - An implementation using Lasers, Smoke andFluorescenceTobias Haist, Ralf Knoll, Andreas LorenzInstitut für Technische Optik, Universität StuttgartPfaffenwaldring 9, 70569 Stuttgart, GermanyJuly 20091 IntroductionBlak Box is a well known game, invented more than30 years ago by Eri Solomon. It rst was pub-lished by Waddington and later by Parker Broth-ers. The objetive of the game is to nd balls hid-den in a regular grid (the blak box) by the de-etion of input balls shot into the blak box. Youmight want to try out the game online, e.g. athttp://www.bieault.org/blakbox/?.This sort of ball-deetion is similar to the deetionof light at mirrors. Therefore, we thought about anoptial realization of the game with the aim to givean impressive display to people wathing the game.2 Optical realizationThe basi idea, of ourse, is to use laser light diretedto mirrors at angles of 45◦. The basi system uses afrequeny-doubled Nd:YAG laser (λ = 532 nm, P ≈10 mW) together with a heap smoke generator (30Euro at eBay).1. The smoke is employed to make thelaser beam visible on its way through the blak box.One main problem is how to make the beam visibleto spetators wathing the player while the playerherself only should see a blak box. To this end theplayer wears laser safety goggles, bloking all greenlight. The over of the blak box is assembled usinggreen transparent plexiglas. Therefore, looking insidethe box while wearing the goggles is not possible. Al-so, the green laser is, of ourse, not visible in this asefor the player.But given that, how should the player know wherethe laser exits the blak box? Fluoresene omes toour help. The border of the blak box is made outof orange uoresent plexiglas. Therefore, the greenlaser hitting the border leads to the emission of or-1More sophistiated smoke generation is neessary if one wants to avoid pollution of the optis.Black Box - An implementation using Lasers, Smoke and Fluorescence2(a) A penta prism is used for the 90◦deetion (left side). Mirrors are glued on a alu-minium sheet glued onto steel balls (right side).(b) Smoke generator () Laser safety goggles are used to hidethe laser and its path from the playerFig. 1: Some omponentsange light whih will be easily seen by the playerwearing the goggles. Additionally, this orange plexi-glas helps for ahieving laser safety beause large partof the green laser light is absorbed (and inoherentlyreemitted).The basi deetion-by-mirror idea only works if theangles of all mirrors are more or less orret. There-fore we used optial rails on the two input sides anda movable penta prism (leading to exat 90◦dee-tion) to ouple the light into the box. The mirrorswere glued (while used as deetors) exatly on alu-minium plates glued on steel balls. The steel balls tniely on the optial breadboard that we used as thebase plate.If you plan to build a similar devie: Be areful withthe laser safety. The impressive glow of the beam andthe edges of the uoresent plasti (total internal re-etion), of ourse, need optial power. This meansthat you have to use some milliwatts to have an im-pressive display. But this also means that you haveto insure mehanially that no mirrors an fall downor tilt in an unexpeted way.3 Is it worth the whole work ?Denitely, the optial blak box game looks spetau-lar in a dark room and it is a nie eye ather. If youhave aess to all the optial devies (laser, bread-board, mirrors) the realization is not so hard. Thegame itself is easily adapted to dierent levels of dif-ulty by using more or less mirrors inside the box.Therefore, small hildren as well as grown-ups mighthave their fun. On the other hand, the game is a littlebit too long for oasions where people want to playonly for about one or two minutes.We want to thank Margarita Riedel for the nie pho-tographs.Black Box - An implementation using Lasers, Smoke and Fluorescence

Black box : an implementation using lasers, smoke and fluorescence

http://elib.uni-stuttgart.de/bitstream/11682/4174/1/lasermaze.pdf

Black box : an implementation using lasers, smoke and fluorescence

Abstract

Similar works

Full text

Available Versions

OPUS Online Publikationen der Universität Stuttgart