Laser pico projectors minimum image size ?

[3dvison]

I was wondering what the smallest image these laser pico's are able to do and still be in focus ?

This one list 15 inches in the specs. but is it true ? I thought the laser projectors could focus at any distance ?
http://www.aaxatech.com/products/l1_las" onclick="window.open(this.href);return false; ... jector.htm

And this one list 6 inches but once again is this truly the smallest it can produce and still be in focus ?
http://www.microvision.com/showwx/specs.html" onclick="window.open(this.href);return false;

If any one knows for shure what the smallest image is please post it.
It would be good information to know for HMD mods ..Thanks

[Likay]

Adding one extra decent quality convex lense will shorten the focusdistance if needed. Don't use too high strength of it though!

[3dvison]

Good to know Likay..Thank You.

Also, will the lasers in these laser pico projectors burn your eyeballs out if you use rear projection...ouch.
It does say you sould not stare into the beam, so I think that would rule out rear projection but if not, please let me know how it could be done in a safe way for the eyes.

Was it true that laser pointers were blinding people ? You would also here about some oher products like mice that had lasers hurting peoples vison, was that just tall tales or is it true ?

[PalmerTech]

Rear projection is fine. Lasers are only dangerous when focused to a point in one spot. Even if you pointed it right at your eye, the scanning would keep it from doing any damage. With a rear projection diffuser, you are fine.


And those stories are all BS. Exposed lasers in consumer products are all Class IIIA, under 5mw. FDA cleared to not do any permanent damage no matter what you do.

[3dvison]

Thanks PalmerTech, I thought those stories sounded fishy.

I also thought I saw a video on Youtube, that said the company which makes the ShowWx was also working on a display that would have a laser drawing the image right onto the back of your eye.
So there must be safe ways for lasers and eyeballs to live together..LOL

Also, can the rear projection screen be made of any material that is found to work well with such a small HMD screen, a screen that could be as small as an inch in size, or does it have to made of somthing special for use with the laser and the safety of your eyes. ?

[PalmerTech]

MicroVision makes the laser projection modules. Yes, they are working on retinal projection. I actually know a fair bit about it, but cannot talk too much.

Anything that shows an image should work fine, safety wise.

Oh, and side note: The projector should be able to focus a lot closer than 6". They just say 6" because that is a practical size, but a 1" projection is very possible.

[3dvison]

Oh, and side note: The projector should be able to focus a lot closer than 6". They just say 6" because that is a practical size, but a 1" projection is very possible.

Looks like your right again PalmerTech.
On the Spec. sheet it list 6 inches to 100 inches but like you said, it was not saying that is the smallest image you can project with it.
So I went and looked in the ShowWx FAQ File and found this. Quote " Projects images of any size, from 6 inches or less to 200 inches or more"
Thanks PalmerTech.

I would think the AAXA Technologies AAXA L1 Laser Pico Projector would be the same, but I will look around the web to find out for shure that it can go as small as an inch just like the ShowWx.
If anyone else knows, please post the information here..
Take care all.

[zacherynuk]

Hi,

Checkout my page here: http://www.wastedspace.co.uk/cms/2010/1 ... %93part-6/" onclick="window.open(this.href);return false; this is with a normal, projector, I know, but adding an extra lens is dead easy.

I am now using piss-cheap plastic lenses from here http://sciencestore.co.uk/acatalog/Opti ... nents.html" onclick="window.open(this.href);return false; and getting fab results.

I'd love to hear what you manage with laser, the greatest benefit, I think, would be the possibility of wrap-around... ie, the projection surface need not be flat.

Also check out the beamsplitters from Edmund optics, if you plan trying a front projection - which IMHO is the way to go : cheap AND lowers A) the risk of eye damage B) the image brightness in a very linear way. - http://sciencestore.co.uk/acatalog/Opti ... nents.html" onclick="window.open(this.href);return false;

Also, I have yet to find a truly good rear projection material. Currently using smoked perspex with a RP film.

[3dvison]

Thank You zacherynuk for all the good information.
Here's an idea. Don't know if it is good or bad.
Could somthing like this (LINK BELOW) be used with less expensive non-laser pico projectors or even larger LCD panels with an image size of 5 or 6 inches ? Could you use this Stereo viewer to center the larger screens to your eyes. Would this work ?
This could be a cheap way to get started on a DIY HMD.
I am shure the FOV would not be very large with that stereo viewer, but what I want most from a DIY HMD, is the ability to use modern day computer video input of 1280*800, even if it is scaled by the pico projector.
The other thing I would like from a DIY HMD is Stereo from two displays, one for each eye not a shutter glasses type of 3d image.
So tell me if you think this or another stereo type viewer could be useed as a simple answer to the optics for a dual display DIY HMD using cheaper non-laser pico projectors or larger and cheaper LCD panels ?
http://www.berezin.com/3d/wheatstone.htm" onclick="window.open(this.href);return false;

[zacherynuk]

Perhaps... I don't know without looking through them - seems like the cards are a good way from the viewer, though, which could cause problems but since the cards are so large anyway, you wouldn't need to do much with the projected image, I suppose - buy one and let us know!

Have a read of this article, also, for some alternative ideas
http://www.lab.ime.cmc.osaka-u.ac.jp/pa ... _paper.pdf" onclick="window.open(this.href);return false;

And see the Demo here: http://www.youtube.com/watch?v=2rvDYF7XCjw" onclick="window.open(this.href);return false;

And then look at the helmet on his website here: http://limu.ait.kyushu-u.ac.jp/~nagahara/Images/HMD.gif" onclick="window.open(this.href);return false;

[3dpmaster]

this is the most wonderful hmd I ever seen!