Laser Tag

[adolfhack]

Dear all,
i got a project that i need to improve
simply its a laser tag gaming system,
i used 940nm infrared led "tsal6100" with 20mm NIR coated lens as collimation optics.
with 80 mW pulsed signal i reached distance of 80 meters with TSOP sensors.

Now a client asked me to increase the distance for up to 200 meters.

im confused between tweaking the same method "LED with optics" or buy IR laser diode?

please advice,
note: in all cases the ray shall be eye safe

 

[gazer101]

Dear all,
i got a project that i need to improve
simply its a laser tag gaming system,
i used 940nm infrared led "tsal6100" with 20mm NIR coated lens as collimation optics.
with 80 mW pulsed signal i reached distance of 80 meters with TSOP sensors.

Now a client asked me to increase the distance for up to 200 meters.

im confused between tweaking the same method "LED with optics" or buy IR laser diode?

please advice,
note: in all cases the ray shall be eye safe

IR laser diodes are dirt cheap, but you'd probably need a laser power meter to ensure that they are eye safe (<mW of laser output)

 

[adolfhack]

IR laser diodes are dirt cheap, but you'd probably need a laser power meter to ensure that they are eye safe (<mW of laser output)

what supplier do you recommend, plus for modulated pulsed beam .. what mW shouldnt i exceed ?

 

[gazer101]

what supplier do you recommend, plus for modulated pulsed beam .. what mW shouldnt i exceed ?

You could get them just about anywhere online (could use eBay: https://www.ebay.com/itm/5pcs-780nm...137857?hash=item27bd35b401:g:JtEAAOSwKfVXIxY2) but testing them to make sure they are eye safe might be tricky.

From my understanding, they should never output more than 5mW of laser light at any given time. For testing purposes you should run a 5mW diode at whatever current its datasheet specifies. But to be 100% sure you calibrated them safely you'd need to use laser power meter (but they are quite pricey)

 

[RedCowboy]

Doesn't the 5mw safety standard takes into account the human blink reflex which is about 1/4 of a second ?
If so I don't know that a 5mw near IR beam would be considered eye safe as a person wouldn't know to blink, it may be safe but I would make certain before using one in a laser tag device.

 

[gazer101]

Doesn't the 5mw safety standard takes into account the human blink reflex which is about 1/4 of a second ?
If so I don't know that a 5mw near IR beam would be considered eye safe as a person wouldn't know to blink, it may be safe but I would make certain before using one in a laser tag device.

Yes you're right! My bad, the laser would need to be <1 mW

 

[Snecho]

Doesn't the 5mw safety standard takes into account the human blink reflex which is about 1/4 of a second ?
If so I don't know that a 5mw near IR beam would be considered eye safe as a person wouldn't know to blink, it may be safe but I would make certain before using one in a laser tag device.

Yes you're right! My bad, the laser would need to be <1 mW

Just make the pulse 0.25s or less

I've always thought about this stuff actually, because my local laser tag arena uses green lasers in their guns and I've never heard about any injuries even from those 5mW-100mW visible green lasers, but it's interesting to think about.

 

[RedCowboy]

Yea I thought about the output needing to be more like a quick shot than a garden hose, still I'm sure there's a legal limit for such items, I just can't say what it is but I'm sure a person could look it up...........also the laser pulse string is likely modulated so the receiver can score what player got the kill as well as who got tagged, it only takes a fraction of a second and 5mw is plenty to reach across a large play area, now how the receiver which you want to have a wide angle differentiates refracted pulse strings from direct hits is another story.

 

[Encap]

Yea I thought about the output needing to be more like a quick shot than a garden hose, still I'm sure there's a legal limit for such items, I just can't say what it is but I'm sure a person could look it up...........also the laser pulse string is likely modulated so the receiver can score what player got the kill as well as who got tagged, it only takes a fraction of a second and 5mw is plenty to reach across a large play area, now how the receiver which you want to have a wide angle differentiates refracted pulse strings from direct hits is another story.

See FDA Minimizing Risk for Children’s Toy Laser Products https://www.fda.gov/media/86481/download

Looks like <1mW is what flies commerciallty.
" Zone equipment is powering over 1500 laser tag sites around the world, and we know how important it is to keep safety at the forefront of everything we do. We have exhaustively researched every possible means to determine the likelihood of injury to any participant exposed to lasers used in our equipment. We have has explicitly confirmed that CDRH permits the use of ‘Class 1’ and ‘Class 2M’ lasers in consumer products, specifically in our equipment. It’s better to be safe than sorry! "
~ from https://zonelasertag.eu/laser-tag-safety/

 

[CurtisOliver]

<1mW is what you need. You are actively pointing and shooting at each other in laser tag. In the UK you will almost never see a >1mW laser in a commercial appliance if the user is exposed to the laser. <5mW is the max for line modules such as that used in handheld laser scanners.

 

[hakzaw1]

hmmmm
never tried these..
i thought the visible lasers red and green are just the 'aiming laser'
and it is an IR the hits or misses the 'target' but i have no other knowledge.
the ones i saw were for kids--at home etc

I never thought about the fact that our eyes do not 'adjust' to IR..
makes sense--

hak

 

[CurtisOliver]

It should also be noted that some have varied responses to IR. Some can see near-infrared wavelengths rather well whilst others can’t. This will affect the responses on a person to person level unless using wavelengths beyond 900nm.

 

[adolfhack]

Thanks to all,
yes beam is short pulses of modulated signal @ 38-56khz
total duration of the pulse is fractions of a second.