Building My First RGB Projector (Opinions?)

[buffo]

There is one other requirement if you plan to rent out your projector to others. (That is, if the operator of the projector is anyone other than you.) And that is a case-intrusion switch. Basically it's a switch that kills the power to the lasers if you open the projector case.

This isn't required for a projector you build and operate yourself, since you would be essentially protecting you from yourself. The CDRH recognizes this, and will allow you to certify your projector without the case-intrusion switch if you are the one operating it. But if someone else will operate it, then that person isn't considered to be "authorized" to enter the case, and thus he must be protected if he opens the case. (Note that you don't have to protect him from electrocuting himself... You just need to be sure that the lasers switch off. Weird, eh?)

It would be good if you got a chance to sit down with a fellow laserist near you so you could see what the inside of a typical projector looks like. There are several PL members in NC - maybe you could get together with one of them over a weekend and geek out... Might want to start a thread in the Meet and Greet section and see if anyone is interested in getting together. (Maybe throw a BBQ party at your place.?.)

Food usually gets people motivated! You provide the burgers, they bring their own beverages, that sort of thing. With any luck, a couple folks will bring their projectors and you can enjoy some laser shows too! I might even be up for a little road trip. You're only 3 hours from me, after all...

Adam

[MisterWilling]

Keep asking questions. For every question you ask, there are 10 people lurking (but not posting) who are wondering about the exact same thing you are.

Haha, thats me! I like this thread so far. I too am building an RGV scanner with no experience in the scanner world. So far I have had quite a few questions answered here so keep this thread going. I will probably start my own thread once I get more parts in and ready. I have some experience with lasers and I have built my own custom laser that combines a red, blu-ray, and green that gives out ~700mW of white light and can fit in your pocket.

Heres what I'm looking at putting into mine: used set of Scanpro 40Kpps galvo's, soundcard DAC, and a couple of program boards. Lasers: red is a homemade module that is supposed it be 635nm at ~400mW powered by flexdrive( I still need to get the multimode diode correctly collimated), blue-ray will be 2 8x diodes combined with a PBS and powered by a flexmod to hopefully about ~600-700mW, green will be an analog modulated 150mW.

[tvojmuc]

Thanks for this blog!
This is almost all what I need and what I would like to know.
I also start with some ideas and now I have XY scanner and driver for, ILDA software which I will develop to the end and soon I will have laser.
Thx again

[Speculative Lasers - Dan]

how are you going to get 400mw from one blu ray?

[buffo]

He said he plans to use 2 of the 8X blu-ray burner diodes. That should put him at around 400 mw of 405 nm... (But I agree, he's not going to see "600-700 mw" out of the pair.)

Adam

[MisterWilling]

It is easily possible but I'm not sure what I want to do as far a power vs. life of these diodes. 8x's have not been tested for long periods of time at high currents, there is some testing being done on these diodes so by the time I build my projector I will have a better idea what current I want to run them at.

I know using blu-ray is not the best solution for a projector because it requires much higher power and this is more dangerous. But for what I'm going to be using this projector for and my budget is... its 10x more affordable then a DPPS blue module.

Here are some of the same brand diodes I will be using and their test results http://laserpointerforums.com/f38/lg...ers-43605.html

[tvojmuc]

I would like to ask one question.
What is maximum laser power allowed or safe for using in door and that is still possible to get visible trace of laser -> e.g like

[MisterWilling]

You need to be more specific, what wavelength are you talking about, will there be smoke in the air? If your talking about blu-ray its going to vary from person to person because its so low on the visible spectrum different people perceive it differently. Its also going to vary from diode to diode because they all don't operate at 405nm, some are higher wavelength and some are lower.

[tvojmuc]

For start no smoke and i would like to have red, green and blue laser - or no blue - yelow or orange or...

I already have 20kpss scanner and software (DAC) will be developed soon because I will combine 26 canal led light show and laser show.
I also would like to add some memory card reader and….but this is only for my hobby and my soul

[buffo]

If you aren't going to have any fog in the air, you will need a *LOT* of power. Figure 5 to 10 watts at least. There isn't enough dust in the air to create the effect shown in the picture you posted unless you've got monstrous power.

On the other hand, if you invest in a cheap fog machine (they can be purchased for as little as $40), then in a completely dark room you can re-create that exact effect show in the picture you posted with less than 100 mw of total power.

For an example, look at these pictures:



These pictures were taken about 9 years ago in my living room. That's 14 mw of red (from a HeNe), 11 mw of green (from a DPSS pointer), and about 25 mw of 488 nm blue from a single-line argon laser. Total output power is roughly 50 mw, yet the pictures are stunning.

Bottom line: you need fog in the air. Go buy a cheap fog machine and you'll be fine. But without one, you'll never get the effects you're looking for.

Also note that even with fog in the air, it is very hard to see the beam from a blu-ray diode - even at 200 mw. Our eyes are just not sensitive enough. You'll see something, but it won't be nearly as impressive as the blue beams in the pictures above.

Adam