I recently got a new DVD player(a Sylvania SDVD7014,if you’re wondering),and I just noticed a few minutes ago that there’s a warning on the bottom of it that says it uses a Class One laser.I may just be paranoid,but isn’t it kind of risky using a DVD player that uses a laser?Or is a Class One laser not strong enough to cause damage?
Sorry for the stupid questions,but I honestly don’t know much about that kind of thing.Any help would be duly appreciated.
(I tried doing some Google searching,but people disagree on whether a Class One laser is harmless or lethal.)
Class 1 lasers are considered “eye safe” under all normal conditions of use.
http://en.wikipedia.org/wiki/Laser_safety#Class_1
ETA: Really - you’re worried about a DVD player? How many people have you heard about that have been harmed by a DVD player (other than having someone throw it at them)?
All CD and DVD drives use lasers to decode the data on the disc.
A class 1 laser is as safe as a laser pointer.
You can misuse it, but honestly don’t worry about it.
If you can find a way to make one work without a laser, you’ll really be on to something.
The bigger the laser, the bigger the worry. But hey, it’s Pink Floyd !!
Can you injure someone with a Class 1 laser? Sure. Tie them down, force their eyeballs to remain exposed and focus that Class 1 directly into the center of the iris.
Otherwise? Meh. Enjoy your DVDs…
You probably don’t want to find out what’s in your smoke detector.
I knew that a laser was needed to use a CD or DVD,but I hadn’t ever seen such a thing include a warning about the lasers,so I assumed that for this particular DVD player’s laser to merit a warning,it must’ve been more dangerous than the other ones.
Thanks for the help.
Too late.
It’s not the fact that the DVD player uses a laser at all that I was worried about,it was the strength of the laser that concerned me.
Thanks to everybody for the replies.
You can buy class IIIa green laser pointers without any special permit. Astronomers use them as aiming aids because, unlike the lower power red ones, you can actually see the whole beam at night. I bought one just for fun, pretty cool.
Practically all CD /DVD drives have warnings about laser exposure on them, at least on the actual drive, whether a computer drive or one inside of something else. Although they aren’t actually that dangerous*, no more so than accidentally getting the sun in your eyes (don’t stare into the beam though).
*By itself, the laser is even less dangerous because the beam is unfocused; I have removed them from the drives and run them by themselves without the lenses; the beam spreads outwards quite a bit, sort of like a super bright LED (even a low-power (20 mA) LED can easily output as much or more light, a few milliwatts at the most), this is only for DVD players though which use a visible light laser.
All right, then, what class of laser is the most dangerous? And how can I go about getting one? Are they expensive? Do they consume vast amount of power? Can I vaporize people with one?
I want to be able to vaporize people who aren’t nice to me.
This page claims that the laser in a DVD burner can be focused enough to be harmful. For purposes of discussion only.
Disallowing special lasers built by scientific and military researchers, the most powerful industrial lasers can cut several millimeters of metal. Here’s Wiki’s article on the classification system: Laser safety - Wikipedia
I have a 30W (Class 4) CO2 laser.
It’s around 18"x3"x4" (but the power supply is pretty big). The unfocused beam will instantly burn wood from across the room.
The most powerful industrial lasers (50KW or so) might be able to cut through a limb pretty quickly, but there are no lasers in existence that are going to be able to vaporize someone, at least not instantly.
Roughly, lasers are classified according to how much eye damage they can do.
Class 1: Not dangerous, unless you manage to stare at it for minutes or hours.
Class 2: If you shine it directly in someone’s eye, they’ll blink before you do any damage
Class 3: Shine it in someone’s eye and you’ll do some damage. But errant reflections aren’t dangerous.
Class 4: You’re going to cook whatever you shine it on. Random scattered reflections can also do some serious eye damage.
Basically, you just happened to notice some standard warnings that don’t actually correspond to real danger. Much like those “zomg everything you buy will give California cancer!” warnings.
These kinds of lasers are also excellent for scattering suburban nuisance birds like Canadian Geese. The geese hate those things.
How much does one of these cost, generally speaking? Why do you have it and what is it used for in a domestic setting?
I actually have two.
I paid around $800 for one of them and $1,000 for the other. Neither came with a power supply.
I’ve been working on a large computer-controlled XY table for many years (it’s turning into a perpetual project). My plan was to automate some of the hobby metal cutting I do with my Plasma cutter, and along the way I got interested in doing some wood engraving and cutting with lasers, so I bought one and then the other.
Turns out that building a laser cutter is a lot more effort than one might think - there are optical, mechanical, alignment and positioning issues galore!
ETA: this is one of the lasers (the better of the two).
Cool, thanks for the info. Did it come with a harness of some kind to put it on a shark’s head? Also…it’s kinda disappointing looking. It looks kind of like a leveler.
How deeply does the laser engrave the wood upon first contact with it? In other words, I suppose that the laser would eventually burn all the way through a piece of wood if left in the same spot for long enough. I can see where you would have some issues using it to engrave…timing, aiming, controlling its motion and whatnot to get your desired outcome.
30W is actually quite a bit of power. The unfocused beam is around 3mm in diameter, and will cause a piece of wood to burst into flame the instant the beam touches it. When used for cutting, the beam is focused into a spot only thousands of an inch in diameter. At that small spot size, the problem isn’t too little power, it’s too much. Unless you can move the workpiece fast enough, you are going to cut too deep (or too wide, due to heat spread). So, you either need to be able to move fast (commercial engravers use a sliding mirror to move the beam in one axis, and a table to move the workpiece in the other), or modulate the beam intensity. The laser the I pictured (an old Synrad) can modulate the beam clear down to zero, which is pretty useful.
Commercial cutters use a lens holder that has a gas inlet. This allows the use of air or Oxygen as a purge, which does a few things - it keeps the cut clean by blowing away char, it keeps schmutz off of the lens (which for CO2 is made from some absurdly expensive material like Zinc Selenide or Germanium or Gallium Arsenide), and it increases cutting rate by oxidizing the material under the beam.
As witnessed by all the Youtube videos, it only takes a Watt or less to burn paper. The key to a successful commercial system is to have enough focused power to cut (or engrave) your material at a reasonable rate. Big systems can do things like cut fabric at hundreds of inches per second. Note that cutting metal is very hard with a CO2 laser - the wavelength of this laser is very, very long - it’s nearly in microwave frequencies, and metals are excellent reflectors at this frequency. That’s why big laser metal cutters often use YAG lasers. The ones that use CO2 lasers have monster ones - like 10-50KW or power.