Laser Pointer

[gblake]

Originally Posted by rich2202

By definition, a laser that produces visible light is a Class 2 or higher laser.

I'm quite sure that this isn't correct.

Rich - Take a fresh look at IEC 60825 & ANSI Z136.1. While they are anything but examples of clear technical writing, their definitions of "Class 1" definitely allow manufacturers to produce visible-light, Class 1 Lasers.

Blake

[gblake]

If I were going to use a laser in an FRC robot, I think I would strongly consider putting a filter that would pass the laser's light, but would block most other light, over the detector that looks for the laser's light.

If the detector was a camera that couldn't do it's job using just the light with wavelengths near the laser's wavelength, I would strongly consider using a filter that had a passband(s) big enough, but not too big, for the camera's other needs.

Removing "clutter" from imagery is usually a good thing.

Filters, and Lasers, can be gotten from many places. Edmond Scientific is one place to look for equipment better than dime-a-dozen, keychain-quality, devices. ThorLabs is another source. These two also sell prisms and lenses that can expand your mechanical mounting options, and/or expand the light-gathering aperture(s) of your detector(s).

Blake

[Jon Stratis]

I've done a little research on the subject, but am not by any means an expert. The classification system relates to device safety, not visibility or color (although I believe those are often a factor in safety). Generally speaking, class 1 lasers are either non-visible OR higher class lasers that are completely contained, such as in a DVD drive. The key there is that the laser in the DVD drive poses no risk, as it's never exposed during normal operation.

As an LRI, I know that I personally do not know enough to judge what class a laser is based on strength and wavelength (those seem to be the two main factors, outside of enclosures). So, I must rely on data sheets - give me a data sheet that says it's class 1, and your good to go. Fail to find such a data sheet, and you have to remove it from the robot.

So please, whatever you find and put on the robot... Bring the data sheet with you!

[gblake]

Originally Posted by Jon Stratis

I've done a little research on the subject, but am not by any means an expert. The classification system relates to device safety, not visibility or color (although I believe those are often a factor in safety). Generally speaking, class 1 lasers are either non-visible OR higher class lasers that are completely contained, such as in a DVD drive. The key there is that the laser in the DVD drive poses no risk, as it's never exposed during normal operation.

As an LRI, I know that I personally do not know enough to judge what class a laser is based on strength and wavelength (those seem to be the two main factors, outside of enclosures). So, I must rely on data sheets - give me a data sheet that says it's class 1, and your good to go. Fail to find such a data sheet, and you have to remove it from the robot.

So please, whatever you find and put on the robot... Bring the data sheet with you!

Jon,

Manufacturers are required to properly label any/all lasers sold in the USA. A proper label(s) includes specifying the laser's class.

You (and FIRST) should think twice about whether you really, really want a datasheet with every laser, or if you will trust the manufacturer's label.

I think you need to decide how to balance the possibility that an unscrupulous manufacturer might put a Class 1 label on a dangerous laser, and the possibility that requiring a datasheet places an undue burden on teams by preventing them from using perfectly safe, inexpensive, mass-market lasers.

If an inspector rejected my robot's properly labeled, class 1 laser, because I didn't have a datasheet for it, I would be mighty annoyed (unless FIRST told me well in advance that I would have to supply a datasheet).

Blake
PS: Lasers emitting any frequency can be Class 1 lasers. The classification system takes into account the multiple types of harm human tissues are vulnerable to, the watts and/or watts-per-second emitted by the laser for the time it might be turned on, the emitted beam's collimation (sp?) in areas where humans might be exposed to it, and the wavelength of the laser's light. If I forgot any other important factors, forgive me.

[cbale2000]

We used a class 1 laser as a visual aiming guide for our 2012 robot. It worked ok in practice but on the actual competition field with all the polycarbonate and longer distances it was so dim that it was impossible to see. It did pass inspection though and I don't think the rules on class 1 lasers have changed in any meaningful way since then.

[Jon Stratis]

Originally Posted by gblake

Jon,

Manufacturers are required to properly label any/all lasers sold in the USA. A proper label(s) includes specifying the laser's class.

You (and FIRST) should think twice about whether you really, really want a datasheet with every laser, or if you will trust the manufacturer's label.

I think you need to decide how to balance the possibility that an unscrupulous manufacturer might put a Class 1 label on a dangerous laser, and the possibility that requiring a datasheet places an undue burden on teams by preventing them from using perfectly safe, inexpensive, mass-market lasers.

If an inspector rejected my robot's properly labeled, class 1 laser, because I didn't have a datasheet for it, I would be mighty annoyed (unless FIRST told me well in advance that I would have to supply a datasheet).

Blake
PS: Lasers emitting any frequency can be Class 1 lasers. The classification system takes into account the multiple types of harm human tissues are vulnerable to, the watts and/or watts-per-second emitted by the laser for the time it might be turned on, the emitted beam's collimation (sp?) in areas where humans might be exposed to it, and the wavelength of the laser's light. If I forgot any other important factors, forgive me.

Most of the lasers I've seen on robots are tiny little things, mounted inside of other stuff, that don't have visible labels on them. I had one just last weekend - the entire thing was about the size of a pencil eraser, press/glued into a hole in a piece of plywood to ensure it stayed properly aimed. It's up to the team to prove to the inspector that a laser on their machine is legal, and for that a data sheet is the best way. I would also likely accept one that was properly labeled as class 1 from the manufacturer, should a team actually show up with one that has a label on it.

[gblake]

Originally Posted by Jon Stratis

Most of the lasers I've seen on robots are tiny little things, mounted inside of other stuff, that don't have visible labels on them. I had one just last weekend - the entire thing was about the size of a pencil eraser, press/glued into a hole in a piece of plywood to ensure it stayed properly aimed. It's up to the team to prove to the inspector that a laser on their machine is legal, and for that a data sheet is the best way. I would also likely accept one that was properly labeled as class 1 from the manufacturer, should a team actually show up with one that has a label on it.

Agreed, especially because if anyone takes a laser-containing device's parts out of the housing the manufacturer put them in, that person might expose themself (and others) to dangerous radiation. The manufacturer's class label describes the original, complete, unaltered device; not all possible (re)configurations of that device's parts.

Creating a danger by operating a disc reader's laser outside of its original case is one example of invalidating a device's original safety classification by altering the device's configuration.

Blake