23 Mar
2009
23 Mar
'09
12:16 a.m.
On Mon, 23 Mar 2009, Alexis wrote:
On Monday 23 March 2009 16:39:20 Jim Battle wrote:
My mind also wanders over to pondering using lasers to do raster images.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
David Griffith wrote:
...
Yes, but the bandwidth of an LED laser is still pretty high. There are a few
laser projectors on the net, but this one goes into the detail of making your
own galvos.
http://elm-chan.org/works/vlp/report_e.html
Just slightly off topic, this is a good foundation for a mechanical television
projector. Modulate the laser to a video source and attach the galvos to two
synchronized sawtooth generators. For PAL, you could get away with a 5MHz
bandwidth (about 250 vertical lines visible).
Mind you the horizontal galvo will be screaming along at 15625Hz, which is
pretty darn fast, faster for NTSC, and I reckon the laser would have a hard
time keeping up. Maybe a Scophony system would be more appropriate. :)
In any case, an oscilloscope will work by far better for TV and for vector
displays, even if the screen is smaller. They usually all have a Z axis input
at the back. Now and then I think it would be nice to have a
vector monitor for
general fooling around. Then I start thinking about using a laser in
place of an electron beam. Hmm... Anyone have any suggestions on
pursuing that?
I'm sure the bandwidth of the electron beam is many times greater than
what you could achieve with a laser.