Hell everyone, I am new to this forum and also to this question, Here is what i need

[muallim]

Hello everyone,
I am new to this forum and also to this question,

Here is what i need:
I am working on one project for which I need something like laser,
but laser can harm your eye so I can't use it. (because it will reflect laser beam back to you from surface that will it hit).

What I need really is something like laser, to have a beam like laser(unimportant which color) and that it can throw light beam minimum one meter and that it can not harm your health and need to be cheap Smile.

Conclusion something that will throw light like laser minimum one meter and that will not hurt your health in any sense and cheap.


For example modern projectors(and some old technologies like overhead projectors) they produce light which can't hurt your health, but I don't need all options that projector has, I only need beam dot
on surface that it hits.

 

[IsaacT]

First: what surface will it be hitting?
Second: does it have to be at a certain power?

 

[muallim]

what surface will it be hitting?
Monitor screen.

does it have to be at a certain power?
Don't know what you mean by that .
Do you mean electrical power or something else.

 

[IsaacT]

Why does it need to hit a monitor screen? The reason a laser will bounce off is because of reflections. The reflections are because of the monitor screen not the laser, so anything you use will be partially reflected by the glass on the screen. Thus, since all light can be reflected, no beam of light, be it laser or otherwise, will be able to pass the screen without reflecting at all.

 

[muallim]

it does not matter about reflection I need that, that reflection
can't harm your health(eyes...)

In other words, you can think that I want to achieve light mouse point on screen.

 

[lasersbee]

I still don't have enough information as to what you
really want to do...or why...:thinking:

1) you can use a Flashlight
2) You can use an LED with Lens
3) You can use a tested 1mW-3mW Laser

BTW....

to the Forum...


Jerry

 

[IsaacT]

okay, so you just want the reflection to not harm your health. My suggestion would be to either get a really low power laser(~5mW) which you could get anywhere. At 5mW a reflection would not harm your eyes at all. Reflection off of glass IIRC is ~4% so 5(.04)=.2 which means if you happened to hit your eye from the reflection, .2mW's of laser light would be briefly hitting your eye. Assuming you have any blink reflex, this will not have a chance in hell of harming you. Also, if the monitor is a convex surface(I know the one my parents use is) then the curve of the glass would spread the beam. The resulting concentration of laser energy would be much less than a tenth of a milliwatt hitting your eye. So there is really nothing to worry about. Just get a 5mW laser. I would suggest red, since the human eye is naturally more sensitive to green light and it would also be the cheapest.

So, 5mW(for safety) red(so that it is not uncomfortable at all if you happen to catch a stray bit of light) laser. You can pick one of these up at any wallmart or Office Depot near you. Although you will pay too much if you buy them in a store. Alternatively, you could purchase it online. A good site would be ebay.

Lastly, I just want to say that if you are moving it around on said screen then the reflection however small would move around a lot, and that might be annoying, especially if you have other people in the same room....and if you have other people in the same room you will need to make sure that they are okay with the reflections and understand any and all danger involved. Some people would not be comfortable with that. In short, if you are using it alone, that is your perogative and a 5mW red will suit your needs perfectly, but if will be around other people I would suggest you reconsider whatever your are intending to do.

Peace,
Isaac

EDIT- @Jerry, I think he wants it be a dot which might be difficult with a led or flashlight. And woops you beat me to the low powered laser part.

 

[muallim]

Thank you very much wannaburnstuff.
One more question how does power voltage influence on our eye(is bigger voltage more harm to eye or vice versa).

I have laser 2A category on it writes :
<1mw [made in China]
wavelength 630-680nm
avoid exposure, dangerous.
what about it.

 

[IsaacT]

well, voltage isn't so much your issue as current. Laser diodes will take a certain voltage and thats it, but feed them current and they will output more milliwatts. So, Voltage is a constant and current is variable. With the pointer you have though, current is already set using a Current Limiting Driver. So, even if you hooked it up to 9 or 10 volts it would still output the same power, the only thing that would occur is the pointer would heat up quickly as it has to dissipate the unused volts as heat.

PS- about the warning, any laser warning sticker will have to include that...basically don't force yourself to keep your eyes open as you point the laser directly into your eye....other than that you will be fine.

 

[muallim]

can we conclude with power voltage of laser can/can't harm eyes (on fabric lasers).

 

[IsaacT]

fabric lasers? If you are referring to a laser capable of cutting fabric then the laser can harm your eyes whether or not you even look at voltage.

If you are referring to a low powered laser, voltage cannot harm your eyes.

You have "milliwatts"(power rating of the laser beam), "voltage", and "current". Voltage affects whether or not it will lase but only current has an effect on the power of the beam, i.e. the milliwatts. Voltage doesn't harm.

 

[Morgan]

fabric lasers? If you are referring to a laser capable of cutting fabric then the laser can harm your eyes whether or not you even look at voltage.

If you are referring to a low powered laser, voltage cannot harm your eyes.

You have "milliwatts"(power rating of the laser beam), "voltage", and "current". Voltage affects whether or not it will lase but only current has an effect on the power of the beam, i.e. the milliwatts. Voltage doesn't harm.

Surely you want to rethink that wannaburnstuff?!!!

I'm fairly sure a few thousand of them will harm you pretty well! ( j/k, I know what you mean, just read funny!)

M

 

[IsaacT]

that's true lol, on the other hand, if someone pumped thousands of volts into a small diode, I think they deserve a Darwin Award :crackup:. Anytime I offer an explanation though if there are inconsistencies I very much appreciate a correction so :thanks:

 

[muallim]

So to conclude laser category II2 with output <1mw
Cant harm your eye, but direct exposure it will.

And somewhere on the internet I read "that lasers of II2 category is like lighter only direct exposure will harm your eye", is this true.


I really need 100% safe solution for this project so can
i get something that is 100% safe and with features that I mention in my first post.
As I mention is there any other solution for this problem, can I achieve this with flash light, lens or is
there something on market that will help me.

Thanks.

 

[IsaacT]

If you are going for a dot then a laser is pretty much your only option. A Class IIA Laser product such as the one you have is only dangerous if kept on the eye for a large amount of time. Any flash of a reflection is virtually harmless.

If you wanted to try a flashlight I suppose you could use a lens to concentrate the beam to a point, but at said point it most likely be more powerful than the laser and you would have to keep it at a set distance from the monitor so as to keep it focused. Also, if you are going for a visible dot, you would need it colored, so something along the lines of a colored LED Flashlight. I would not suggest this option as it is overly complicated and would be a huge pain to set up. The Class IIA Laser you already have will be sufficient and perfectly safe.

Good Luck!

 

[Bionic-Badger]

that's true lol, on the other hand, if someone pumped thousands of volts into a small diode, I think they deserve a Darwin Award :crackup:. Anytime I offer an explanation though if there are inconsistencies I very much appreciate a correction so :thanks:

You can "pump" thousands of volts into a small diode and not get killed or maimed (can't be said for the diode though). That's what happens with static electricity.

The important thing is that you don't have too much voltage and current going through your body.

muallim:

If you need it nearly 100% safe, you'll need a Class 1 laser. Still most class 2 lasers should be safe enough unless you're purposely trying to stare into the beam for a while.

If you need something "laser like" try getting a flashlight with a long "throw" to it. It won't be quite as laser-like as a real laser, but if it looks like a beam people may think it is close enough.

I would just get a red laser pointer and some fog. What people interpret as "lasers" is a beam, so if you have some fog it'll make the laser look like one, and the laser doesn't need to be really powerful.