[time-nuts] Time shown as two horizontal bars

[Chris Albertson]

On Tue, Apr 2, 2013 at 1:42 AM, Don Latham <djl at montana.com> wrote:
> So all you need is one spinning mirror and two laser pointers side by
> each? one track for hours and one for minutes.

No,  Just one laser pointer.  It you want two dots you turn it one
twice per scan.  If you want 100 dots you turn in one 100 times per
scan.   Feed constant DC current to the laser and you get a solid line
all the way across.  So basically you turn if off when you don't that
part of the line to show.

Laser printers do the exact same thing but with much greater precision.

You think of this like a CRT tube but with a laser rather then an
electron beam.  You can draw just about anything on a CRT.  The trick
is to keep the beam modulation in sync with the scan mirror the scan
motor will make a pulse you can use for that.

--

Chris Albertson
Redondo Beach, California