Comments on: RGB laser diode projector

By: james

james — Tue, 07 Sep 2010 01:34:18 +0000

You can’t change the color of a HeNe tube by simply changing the gas. The color is determined by the mirrors, with HeNe tubes available in IR, orange, yellow, green, as well as the common red. These “other color” HeNe tubes are much less efficient so they are a much larger more carefully constructed tube for a given output. It is not possible to get blue from one.

Until relatively recently, the only practical way to get a decently powerful blue beam was an argon-ion laser. Most big laser shows out there still use a mixture of argon and krypton ion lasers, occasionally a single laser with a mixture of argon and krypton using multiline optics. The argon provides the blue and green with the krypton producing the red. These are separated, modulated, recombined, and then scanned with mechanical galvos to produce the display. Some use a PCAOM to modulate the beam while older setups used mechanical galvos to do that too.

By: James

James — Thu, 26 Aug 2010 23:11:17 +0000

Raster scan laser video projectors have been made, but the power required is immense. The one I saw details on used large frame argon ion lasers for green and blue with one pumping a dye laser for red. The thing required tens of kilowatts, water cooling, and was the size of a small car. It could be done today using solid state lasers, but a better approach is to use the lasers as a light source and create the image with a DLP chip.

By: Plugo

Plugo — Tue, 16 Feb 2010 19:23:38 +0000

I’m interested to see if this is the same technology going in to the current laser projector units. I’ve been looking at the aaxa l1 laser projector and it seems that the technology is very similar. Was wondering if you would agree…

http://www.aaxatech.com/products/l1_laser_pico_projector.htm

By: conundrum

conundrum — Fri, 02 Oct 2009 15:46:55 +0000

the reason why DPSS can’t be switched quickly is due to the way they are driven- i.e. a >0.5W IR laser with active temperature feedback to keep the cavity at the optimal temperature for 532nm production.

one way to get around this would be to add a small LCD panel in the beam path, and increase the drive voltage to the panel as well as running it at around 50C to make it switch more quickly.

By: just a bonehead

just a bonehead — Sun, 15 Mar 2009 21:27:28 +0000

why not get yourself some old glass He-Ne laser tubes and figure out what gases would make a good blue, fill the tubes with a high quality He-Ne gases an play around with the high voltage supply’s try the DLP chip set with a MIX of all three what could happen you could make a “frickin laser” that could blow up a 3rd world or something lol

By: Mary Diane Troyer

Mary Diane Troyer — Tue, 16 Dec 2008 20:56:15 +0000

Also look up on Youtubes Metatroy to see the
Z*Tron Vision laser projector.

By: Mary Diane Troyer

Mary Diane Troyer — Tue, 16 Dec 2008 20:54:57 +0000

also look up Metatroy you tubes to see video of laser projector.

By: Mycroft

Mycroft — Fri, 13 Jun 2008 00:56:07 +0000

@ orv/#5

Someone did do a vectormame port for a laser controller, LazerMAME, but the project has been dead for a long time. (The project made me a little sad – it couldn’t handle the two Atari vector games I _wanted_ to play, Star Wars and the Empire Strikes Back.)

By: ...

... — Wed, 11 Jun 2008 09:30:44 +0000

This project looks a lot like the RGB laser I have been working on, except that it has a bit more power and is much larger. Kudos for getting the alignment on the first try!
http://krazerlasers.com/lasers/

As to doing image projection, it is entirely possible to project images using a rgb laser, either by using a set of DLP chips, a mems based scanning mirror, or even a rotating mirror and galvo assembly, but you run into problems that you need very fast bitrates into the lasers (30fps at 1024x768 is 23 millions pixels/second, DPSS lasers can't change their output that quickly, nor can many diodes), and an overall lack of power output. Most of these lasers only get well under 1W of overall power ouput, which is about as much as a single luxeon LED, not that impressive for a big display...

Give it time, there are already talks of getting some high power 570nm laser diodes to get multawatt lasers within the price range of a decent TV.

By: Rager

Rager — Tue, 10 Jun 2008 11:12:01 +0000

Well, for those who thought it could never be done to make a real projector:

http://www.colorvision-lasers.com/displays.aspx#

It can, but it's extremely expensive for cinema-style ones. The upshot, though, is that images are so much more colorful and vibrant.

By: Greg

Greg — Tue, 10 Jun 2008 05:03:52 +0000

@#2 – ROFLMAO

I love the Austin Powers reference!

By: Hello1024

Hello1024 — Tue, 10 Jun 2008 00:42:26 +0000

GrizzlyAdams: I guess the problem is total power output. If you wanted a fully filled in image, you might want say 10W of visible light output – there aren’t many lasers that can output that for a reasonable cost.

By: Orv

Orv — Mon, 09 Jun 2008 19:35:46 +0000

Someone needs to write a MAME driver for this so he can play Asteroids on his wall. ;)

By: evillawngnome

evillawngnome — Mon, 09 Jun 2008 18:14:33 +0000

@GrizzlyAdams:
The lasers can be focused, just like any other type of light. In this manner, we can get a large or small "dot".

So then, it should simply be a matter of pulsing on and off with the rotation of the mirror to produce a rasterized image.

By: Pragma

Pragma — Mon, 09 Jun 2008 17:46:40 +0000

@grizzlyadams: I couldn’t agree more. I suppose all you’d need is some faster mirrors, and some equally fast processor to tie them all together.