Projection clocks (e.g. which shine an image of a clock onto your bedroom ceiling) are very handy.

This idea for a clock which uses a laser pointer to draw out a clock face and hands. It will have the nice clean, crisp lines of laser projection systems and be configurable - you can choose a digital display if you like with a range of fonts.


(In theory this could be hooked up to your PC to project any vector graphics format. This would be better than the alternative of using one of those screen projection systems to project a configurable clockface - (1) Laser pointers are low power and so don't need fans, (2) For just a clock, a single colour is enough).
-- hippo, May 22 2003

Laser clock pen http://thelaserguy.com/lasclocandpo.html
[thumbwax, Oct 05 2004, last modified Oct 21 2004]

It's a great idea hippo, this guy already built one. http://www.circuitc...e/M295-abstract.htm
[ato_de, Oct 05 2004, last modified Oct 21 2004]

Home Built Laser Projector http://elm-chan.org...s/vlp/report_e.html
Build your own galvanometers. [Ouroborus, Jun 01 2006]

I want a Dali-esque fried egg one. +
-- saker, May 22 2003


[thumbwax]'s link has confused me. Does this operate as that does? What I was imagining was a laser using a similar concept as a tv, tracing the time on the wall....
-- silverstormer, May 22 2003


I too am confused by [thumbwax]'s link - I can't believe it does what it seems to say it does...

[ato_de] Breathtakingly halfbaked - especially the picture of his working prototype. It reminds me of a Baird TV system.
-- hippo, May 22 2003


Just to pick nits, the system shown in [ato_de]'s link is a raster-rendered image, not a vector-rendered one. For most people that means little to nothing, but I assure you there are some applications where vector imaging is much better suited than raster imaging (not that a household projection clock would be one of those).

As for the projection-clock- in-a-pen, I think its manufacturer must be using some slick technology to create the display. It's probably a direct laser projection through a small LCD and lens system. For an analog clock face, a trio of diffraction gratings (one for each hand, plus one for static markings) rotated by stepper motors could produce the desired effect.
-- BigBrother, May 22 2003



random, halfbakery