Great results Fairlane , where did you get your line lens from ? And also how many mW is the ir laser you are using?

Fairlane - 03 July 2008 10:31 PM

royc - 03 July 2008 12:18 AM

Thanks fuz3! I’ve got a line lens(as attachment). It creates very nice laser line. I am still looking for 850nm IR lasers. I will setup and test it after I found 850nm IR lasers and IR pass filter.

Hey royc, these are the laser modules I have used in my Laser setup tests. I removed the Red Laser and inserted a DVD-Rom IR laser diode. I needed to remove the current limiting circuit and built my own.

Here’s a quick video of one of my tests with these lasers.

Thanks AlexP for the great idea to introduce lasers in MT setups!  I’m going to have so much fun!

Congrats Fairlane!!!
Thanks for the great video. Awesome work!

~Alex

Vlado - 04 July 2008 06:06 AM

Great results Fairlane , where did you get your line lens from ? And also how many mW is the ir laser you are using?

Hey Vlado, the laser modules I bought were from DealExtreme. The link is here.
I’m not actually sure on the mW of the laser diode I used, but i’ll try and find out. The info I have for the IR diode is:

Wavelength = 785nm
Operating Output - Read Mode = 1.07mW, Class 1
Maximum Output = Class 1M

Then to confuse things more, there is a warning stating that the Visible and Invisible lasers are Class 3B.
Class 3B is up to 0.5W in output power for the diode (and I know that it’s most likely not 1mW), so I’m not really sure.

Thanks Alex, couldn’t have done it without your kick-start!

Thank for the info about the laser , what about the line lens?Also what camera are you using? Smoke is really fast.

Is it beacause of the clear white blobs or beacause your camera is running at 60FPS?

I bought some IR Lasers from ebay for abot 30 bucks and they sold me the line lens for 7 bucks. As soon as they get here I will post my results.
here is the link http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=360050925042&ssPageName=STRK:MEWN:IT&ih=023

Vlado - 05 July 2008 07:17 AM

Thank for the info about the laser , what about the line lens?Also what camera are you using? Smoke is really fast.

Is it beacause of the clear white blobs or beacause your camera is running at 60FPS?

The line lens is part of the Laser module from DealExtreme. The link I posted earlier is for the Focused Line laser which has the plastic lens attached to the module.
(see Pics).

My camera is an Xbox Vision 360 running at 320x240 @60fps. I think it’s a mixture of Bright blobs, a ‘not bad’ PC, and sensitive camera. Oh and also all the Touchlib speed fixes that people have posted helps too.

Aha , got it about the line lens but I’m still confused about it’s placement.If you place it farther away from the laser it creates a laser plane? Or do you place it in an angle away from the laser a bit.
Beacause the one from dealextreme says it’s a focused beam , so that’s why I’m asking.

Hello & WOW!
Lots of good reading.
Along with a optical line glass to create a single plane, used surplus polygon scanners (5-sided spinning mirror) can be purchased on-line or made using the motor of any CD-Rom and small square pieces of a mirror. Each polygon scanner would be placed diagonally from one another.

I’ve been trying to incorporate a IR laser method of illumination built into a frame that would fit over any 42 inch LCD screen. Eliminating the projector and the need for a large cabinet.

Thanks!

Vlado - 06 July 2008 05:25 AM

Aha , got it about the line lens but I’m still confused about it’s placement.If you place it farther away from the laser it creates a laser plane? Or do you place it in an angle away from the laser a bit.
Beacause the one from dealextreme says it’s a focused beam , so that’s why I’m asking.

The line lens mounts directly on the collimating lens so no need to worry about that.
There are two distinct steps here:

1. The beam is focused by the collimating lens
2. The focused beam is then spread by the line lens

The only thing you’d have to worry is the angle of the light spread.
Dealextreme does not specify what this angle is. So it would be great is someone can measure it.
Ideally you would want this angle to be >90 degrees so to minimize the number of laser modules used to cover the surface.

~Alex

Aha ok I understand , thank you Alex.

Caesar - 06 July 2008 07:58 AM

Hello & WOW!
Lots of good reading.
Along with a optical line glass to create a single plane, used surplus polygon scanners (5-sided spinning mirror) can be purchased on-line or made using the motor of any CD-Rom and small square pieces of a mirror. Each polygon scanner would be placed diagonally from one another.

I’ve been trying to incorporate a IR laser method of illumination built into a frame that would fit over any 42 inch LCD screen. Eliminating the projector and the need for a large cabinet.

Thanks!

Hey Caesar,

I thought about doing something like this (use of rotating mirrors) a while ago.

A few issues with this method:

1. Mechanical parts involved make is less reliable
2. Mirror alignment is tricky
3. Hard to sync the motor rotation with the camera shutter timing
4. Problem with the blob brightness since each object will be hit with the light for very short amount of time
5. Sensitive to mechanical shock
6. Way more expensive than line lens
7. Too complex comparing with simple fixed line lens
...

Well, you get the picture.

~Alex

I have a drawing of an idea.
I should get a 90 degree angle with my line lens.
Was wondering how close the lasers can be to the Plexiglas edge? and if this placement is ok?
I don’t have them yet to test my plan. Trying to do some leg work until they get here?

justin - 06 July 2008 04:48 PM

I have a drawing of an idea.
I should get a 90 degree angle with my line lens.
Was wondering how close the lasers can be to the Plexiglas edge? and if this placement is ok?
I don’t have them yet to test my plan. Trying to do some leg work until they get here?

The one problem you might have is that the laser light at the far edges of the lines is not as unifirm as it is elswhere. This is the reason why I chose to go with wider angle such as 120 degree.
Other than that your setup should work good. Besides the line spread angle, there are no restrictions in laser placement. So you could place lasers as close to the edge as you can.

~Alex

justin - 06 July 2008 04:48 PM

I have a drawing of an idea.
I should get a 90 degree angle with my line lens.
Was wondering how close the lasers can be to the Plexiglas edge? and if this placement is ok?
I don’t have them yet to test my plan. Trying to do some leg work until they get here?

Hi Justin,

The reason you would use 2 laser over 1 laser is also to prevent a finger blocking the laser beam and any finger behind it not being recognised because its in the shadow ..
If you set the the 2 lasers across each other as done in your picture you can still get this effect if you have 3 fingers on the same line..
If you put the lasers on the same side (left and right bottom corner) it is alot more difficult to block the laser beam