About the Lasershark projector

[zhang]

Hello, Nelson,

I'm a student from Image Lab, and the research which we are doing now needs to project an edge video with a laser device.

At first, we found the Openlase, feeling it so nice but we don't know how to start with the hardware(Our lab seems not be so familiar with the hardware things). And now we found your Macpod homepage. Although the tutorial of the hardware assembling is written, we still have no idea how to start because we don't familiar with the electronics board, so we want to know if it's possible to buy a set of a projector like this.

http://macpod.net/electronics/lasershark/lasershark_media.php


Or can you just give some advice about how we can choose the other components(supposing that we bought a shark board from you)to DIY a  laser scanner which can fit with the Openlase? We are not sure the components we found can be assembled and work together well.

We are looking forward to your reply! Thanks so much!

[Macpod]

Hi, thanks for re-posting this on the forums. Answering the question in the public forums helps others searching for this information to find it.

Unfortunately I do not sell full projectors. This would classify me as a laser projector manufacturer and significantly increases requirements such as the need to handle laser variances.
Speaking of this, for your application, please verify that for your application your projector work follows all necessary laws and regulations in your area.

I am happy to review components if you post them here to determine if they will work or not.

Can you describe in more detail the complexity of these images you would like to trace? Do you have examples? This will impact the speed requirements of your galvos.

Do you also know what surface you will project onto, how far away this surface will be, the brightness of the room, and finally the laser colors you wish to use?

[zhang]

Thanks for your reply!

So it seems that it's necessary for us to DIY the projector ourselves.

As for the necessary law of laser, I'm sure there is no problem for a 100-200mW laser device, despite the fact that we've already obtained a 400mW laser light.

The complexity of the images is simple(some edge images from the programs which use like Canny edge-detection) and project it onto the ground we walk. Projections of them on the ground may be echelons but we would fix it. The height of the projector is about 1m-1.5m and the color or the brightness is not so important for us. After all, it's the first try of it, and we may do the adjustment of them if the prototype works well.

The components may be:
1.The laser shark DAC board from Nelson.
2.a 100mw 532nm green laser module 5V with TTL.here
3.Galvos and Galvo amp: a XY galvo is enough as long as the laser's wavelength in the galvo's wavelength range ? But amplifier and the power of them we are not sure what to purchase. It may takes long to get all the components from Internet so we are cautious about which and what to buy.

Sorry for my poor descriptions and hope for some advice !

[Macpod]

In the U.S. anything 5mW and over requires a variance. A 400mW laser would not be responsible to use in this application as it is both extremely dangerous and far too bright to look at!

For experimentation I would suggest a 4.999mW 520nm laser. I would suggest a 520nm direct drive vs a 532nm DPSS laser as you do not need to worry about leaky infrared light:
https://www.youtube.com/watch?v=iR1Ku5dnbH8
532DPSS lasers are also sensitive to temperature and can take a while to heat up if operated in a cold environment. 
Human eyes are particularly sensitive to green light so you do not need much (In a darker room I have used a 520nm projected on a projection screen 5M away to demonstrate lasers to students).

Galvos are usually sold as a kit consisting of the galvo, galvo amplifier, and power supply so you will not need to worry about matching these. You will need to determine the necessary KPPS (kilo-points per second) rating of the galvo. This will be dependent on how complex your shapes are. The faster the galvos are, the more traces per second you can draw and this will reduce "flickering" of the images.
Since you will be projecting images onto a surface in close proximity to the ground you will also need to account for the maximum galvo angle your galvos support.

[zhang]

Thanks for your advice!

And here's now some alternatives of components.

1.DAC board: laser shark Dac board.[/sup]
2.Emitter subsystem: At first we found this.520nm Green Laser Diode Module
It is straightly powered by a DC input power supply optional. But we found that it has no TTL modulation or analog modulation.

BTW, we want to know the reason why you suggest us buy one which capable of TTL or (ideally) 0-5v analog modulation. For RGB laser, the TTL or analog modulations may change the color of lasers, and of course the analog way can change MORE. But for a single color laser, what is the use of an analog modulation? Google told us that

TTL only controls the on/off of a laser and, it can make the patterns "clean", which means no connected line of each letter if we want to project a word"LASER".

Dumb question but I just want to know is it right and what for an analog one. (may control the brightness according to input voltage?)

And here are some other alternative lasers(feels hard to find a 5mW or about ones. ):
     <sub>1.w/12V AC Adapter 515nm 520nm 50mw Grass Green Laser LINE Module Osram LD TTL

     2.10mW 515-520nm Direct Diode Green Laser Module (Adjustable Focus) with TTL Modulation (12V)</sub>



3.Scanning subsystem:
     <sub>1.40Kpps High Speed galvo scanner for laser show lighting/RGB Laser system ScannerIt says that it acquires the "Deflection angle: max 70° optical (factory calibration @±25°)" and we are not sure whether it is enough to project patterns in the height of 1-1.5m to the 2-3m far distance from where it is set.

     2.
30Kpps HightSpeed Galvo scanner for Laser light show or 3D printer (max50Kpps)
It looks like that all the galvos detailers have the similar description of the spec details</sub>

4.And some cables or board to set them up. Or maybe a laser glasses?

[Macpod]

A TTL laser will let you turn the laser on or off. An analog laser will let you make the laser brighter or dimmer. This is useful as it would allow you to have different line brightnesses in a lasershow. For example if you spelled out LASER, you could make the L very bright while the R could be made very dimm.

You can also make the laser look brighter or dimmer by turning it on/off very quickly with a ttl laser too but to make this happen with a lasershark you would need more hardware.

2.Emitter subsystem: At first we found this.520nm Green Laser Diode Module
It is straightly powered by a DC input power supply optional. But we found that it has no TTL modulation or analog modulation.

While you could use this laser, it would have to always be on (because there is no way for the lasershark to control it). I would not recommend this as the beam can still look very bright if the galvos are not moving. There will also be traces between shapes

And here are some other alternative lasers(feels hard to find a 5mW or about ones. ):
     _{1.w/12V AC Adapter 515nm 520nm 50mw Grass Green Laser LINE Module Osram LD TTL}

This is a line laser module As opposed to drawing a dot, it draws a line. You would not want this

     _{2.10mW 515-520nm Direct Diode Green Laser Module (Adjustable Focus) with TTL Modulation (12V)}

This one would be OK. It is greater than 5mW and would require a variance in the U.S. in some use scenarios. To make it dimmer you may be able to adjust the potentiometer but be careful as you can also make it brighter if you turn it the wrong way. You may find the block-format the laser is in very helpful for mounting reasons (you will have to align the laser with the galvo mirrors carefully)

I like that this unit has a fan too. I also see LaserLands sells these for a little cheaper (this is not an endorsement for laserlands):
https://www.laserlands.net/diode-laser-module/520nm-laser-module/3350-520d.html

They also have a 20mW laser that could likely be dialed down power-wise 20mW would still be very bright for your application:
https://www.laserlands.net/diode-laser-module/520nm-laser-module/focusable-515nm-20mw-green-laser-module-osram-ld-in-12v.html

3.Scanning subsystem:
     <sub>1.40Kpps High Speed galvo scanner for laser show lighting/RGB Laser system ScannerIt says that it acquires the "Deflection angle: max 70° optical (factory calibration @±25°)" and we are not sure whether it is enough to project patterns in the height of 1-1.5m to the 2-3m far distance from where it is set.

     2.
30Kpps HightSpeed Galvo scanner for Laser light show or 3D printer (max50Kpps)
It looks like that all the galvos detailers have the similar description of the spec details</sub>

I would recommend using geometry compute how wide a scan angle you need. Both of these galvos kits seem more expensive than they should be.

4.And some cables or board to set them up. Or maybe a laser glasses?

Safety glasses are a great idea. You will need to purchase glasses according to the wavelength of light you will be using. They usually protect against one or more ranges. I.e these pair covers 190-540nm with an OD5 rating:
https://www.survivallaser.com/Eagle_Pair_190540nm_OD5_Standard_Laser_Safety_Goggles/p556088_2780808.aspx

Frequently the galvos kits come with the cables to connect the gavo amplifiers to the Lasershark. I would reccomend waiting for those to come in before buying cables. You should start thinking about making a mount to align the laser with the galvo mirrors.

[zhang]

Thank you very much! Sorry to reply so late because of the login session error these days on the forum.

Now we are about to buy components and start to think about how to make a mount to combine the galvo and laser pointer. (Of course other things too) Maybe a wood pad easy to deal with? (like the v1 lasershark macpod).

As for the necessary angle of galvos, it is difficult to assert how large the angle we need. Therefore, we'd choose the one with a reflection angle as large as possible and the fast speed. (marcan's and now the one we decided all 35°(max 70° +- 20°) ) The laser show projector now we used can only project a small pattern on road than the one we want(attachment 1)

And a thing must be confirmed that are there some troubles in running Openlase in Windows 10? The software we developed is now running in Windows, and if it must do it in Linux, we have to do some adjustments right now.

Edited: And the 12V PSU for the laser pointer always seems too high. The working current of the laser pointer is about 200mA but most 12V output PSU can't supply the low current. On the lasershark v1 board, I found that you have two PSU and connect the small one to the large one. So one AC input is enough. Shall we do this?

[Macpod]

For a prototype you could use wood/screws and thin cardboard (i.e. cereal box) to shim/align items. If you have access to a 3-d printer you could design a mount that way.

I personally have not used openlase under windows 10. I have also only compiled lasershark_jack for Linux which is needed to use a LaserShark with OpenLase.

While it is important to match PSU voltages it is not a problem if your power supply can supply more current than the laser/etc designate. Normally when I spec I PSU for a project I make sure the current rating is at least 20% higher than what the circuit calls for.

[zhang]

Thanks so much, and we just have a 3D-printer from last month. Still at step like trying to copy small component of Segway and it seems to be a good start.

And I see..we'd better do our task on Linux. If you come back please let us know and we'd like to order Lasershark straightway.