AVR Laser Projector

I’ve seen a few simple DIY laser projectors that just oscillate the beam. This one (scroll past the pong game) has 16 lines of resolution. Sixteen mirrors are rotated by a motor, and an AVR controller pulses the laser to draw the image. Via Asish’s Programming Journal (Worth checking out, he’s been doing several webcam laser pointer projects.)

22 thoughts on “AVR Laser Projector

  1. dood, this is the second repeat (the ds mod being the first) hack this week!

    And worse yet, you spelled Ashish’s name wrong!

    In any case, yes the laser scanner is cool; I think it would be put to best use aimed at a wall (with the beam somewhat unfocused to give a nice usable spot) so that you could play pong on a 100″ screen :P

  2. will this have the same problem as the virtual boy of causing severe eye strain after a relatively short while? some games on the virtual boy had break periods every level or set time limit because your eyes get messed up with oscillating light sources or something like that, it ad to do with the lasers and mirrors.

  3. to #4

    i’m pretty sure collimated, monochromatic light doesn’t mix the same way as ‘normal light’.


    I think the virtual boy’s problem was that you had your eyes in that hood, rather than looking at a wall.

  4. That is a nice project! I have seen this rotary laser projector in a magazine and they where using a cpu fan for the motor, they removed every fins and glued mirror. YOu have 8 mirrors and every mirror is incline so that the laser is pointing higher then the previous mirror.ELECKTOR n:339 septembre 2006 page68, let my fin de link… nope the guy website has nothing, two line of text and the zip file.( the file is even corrupt) Here is a tiny pictures to have idea.

    I have to get back to my robot sumo



  5. The problem with the virtual boy was that you had your head in this hood, looking at an image which MAY or MAY NOT be adjusted and focused properly for your vision. Also, the image in the virtual boy was made using 2 dot matrix LED screens, not lasers. There was one screen for each eye, which gave you the stereoscopic illusion of 3D. There were mirrors pointing to the two screens, and a lens system. A knob and slider on the top of the VB adjusted the ditance between the screens, (ie, how far apart your eyes were) and another adjusted the focus.

    My memory might be a little off, but i think you guys get the idea.

    That said, i think it would be really interesting to see this done with 3 lasers. Im fairly certain the light WOULD colimate properly, but blue lasers arent exactly cheap. If anyone is seriously considering it, the cheapest source of a blue laser would be a PS3 Blue Ray drive. But, that makes me wonder: What about the laser in a HD-DVD drive for the x360?

    All in all, i think this is a cool project and id love to see some people building off of it.

  6. to #9

    It dosn’t seam possible to me that there are no blue lasers to be had for less than a couple hundred dollars (or whatever broken ps3’s are going for these days). But then, I’ve been wrong before… :)

    (btw, the “blue”-ray laser is closer to violet than blue)

  7. Well, if that laser didn’t need a power supply (~$100-200) and a regassing ($2k+) it would be great…

    You could do a red/green/yellow pretty cheap with a few dicrotics and a green laser pointer… But to add blue you would be best off buying a xbox hddvd drive…

  8. Regasssins costs soo much becuase you can’t just blow some argon into the laser, you have to hook it up a vacuum pump, get the pressure extreemly low (thousadths of an atmosphere) then bake the tube to get impurities out, then probably replace some optics, and then regass it. and You are paying the guy doing the work somewhere arround $200/hr…

    The lasers out of a blu-ray drive are .35mw, and the laser out of a hddvd is .5mw so it isn’t all that bright. If you use a burner then you can get over 20mw…

    The beams exits the laser ~1um by 100uf (rectangle) and is highly divergent. This is culminated by a concave lens, which is later focuses down onto the disk. So if you remove the focusing lens on the optical assembly of a drive you will get a colminated beam (probably ~2mm in diameter).

  9. Red Green And Blue Lasers, will colminate and mix their colours perfectly well, it may be off white, however this can be corrected with modulation of the beam (i.e. if there is too much blue, it can be reduced by using PWM on the beam) However blue laser technology is way to expensive for hobbyists (and not developed enought to fit the DPSS crystals required for a high output in a small housing) Which is unfortunate, however if things go the way they have with Green DPSS lasers over the past few years, we should see 100mw blue modules for around $150! (I hope! :):) )

  10. Could blue LEDs be used instead of lasers? I know little about optics, but since lasers need optics to create the parallel beams anyway, why not start off with a LED? The coherent properties of the laser is not what’s important. The only requirement for a “laser” projector, is that the light source is very focused.

    Regardless of the kind of light source, though, I think it will be difficult to get all three colors to shine on the mirror wheel from the same direction. But maybe there exist some color-dependant mirrors which could solve this? Alternatively, one could place the laser / LED-pseudo-laser right next to each other, then let Red draw pixel (0,0), while Green draws (5,0) and Blue draws (10,0). Kind of like drawing with an RGB fork. Looking at a given pixel, it will be drawn with B, then G, then R with slight pause between. Due to persistence of vision, though, this will probably not be noticeable.

    For you who want to continue the quest for a HDTV RGB laser projector: Primary problems with our design was:
    * Low light intesity. A laser pointer spread over 10x10cm or something like that is not very bright. More powerful lasers are of course a bit scary to work with, so we didn’t even think of that. This was just a simple for-fun-project, no intentions of very advanced stuff.
    * Mirror alignment: Very tedious work!

    The TinyProjector (comment #5) looks cool. A mobile device projector, as mentioned there, is maybe a more suitable application of laser projectors than HDTV. If one should attempt to create a 50″ TV using laser projection, you will always have the basic problem of beam intensity. If the mirrors for some reason stops, you have a multiple-watts beam shining in the same direction, so you have to make absolutely sure that this is detected so that the lasers can be automatically turned off. If not, you could start a fire with the beam or cause flash-boiling of eyeballs looking into the projector.

    Anyway, good luck to anyone trying to figure out the next step!

    Co-creator of the AVR video projector.

  11. to #18, thats a good idea, if the surface onto which the image was to be projected was a resonable distace away, the low beam divergance of lasers would be unnecisary.

    to #17, I don’t think PWM would work well in this application, as the frequncy would have to be very high if the single pixles were to be maintained

  12. #19 That is one thing that I thought of, there are analogue dimmable lasers out there, but they requie bulky electronics. Sitting beside me I have a 100mw red and a 100mw green laser, and I’m seriously tempted to make a two colour projector, however I’m lacking an AVR programmer, and the knowelege to adjust the programming accordingly.

    #18 Using 2 partially refelctive mirrors, placed at a 45 degree angle to the green beam and square to the red beam will mix the laser light, and these mirrors are found in all CD drives, used to let the laser light from the diode pass through (i.e. the red beam in my situation above) and bounce the highly parallel beam from the cd being read back to the sensor. I myself have salvaged a few of these mirrors and tested them with my two lasers, and I have been able to create a nice yellow beam. I think you may be onto something with the LED idea, however lenses to collminate the beams to such tight spots could prove tricky to fit in a small space. Anyway I’m only a laser hobbyist, and the only knowelege I have is through doing experiments of my own, but if you require any more information don’t hesitate to contact me.

  13. Sorry I made a mistake in my last post, I meant 1 partiallty reflective mirror, 2 would be required to produce a white beam consisting of R,G,B Lasers.

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