Infrared touch screen

[newday07]

Hi!,
Infrared touch screen can effect your eye in any way?

I understand that Infrared light is the predominant carrier of the energy delivered to us by the Sun and that the infrared leds on an ereader are small, but in this case we look directly at the screen. I have read that IR can cause eyes problems like cataracts for ex. What is the IR emissions of a single led? and how many LEDs are there in a screen?

[meeera]

The IR touch beams aren't aimed at your eye, they're aimed across the screen.

The sorts of levels of radiation that cause cataracts are massive - hence the moniker "glassblower's cataract". However, glassblowers were exposed to a wide spectrum of radiation (and toxins), not just infrared, so it's not at all clear that even those huge doses of IR were causative.

Your best bet when it comes to reducing your risk of cataracts is to not smoke, and always wear good sunglasses & a hat outside. Or don't get old. That works too.

[newday07]

Originally Posted by meeera

The IR touch beams aren't aimed at your eye, they're aimed across the screen.

thank you for your reply
What do you mean by "across the screen"?

I bought a Tolino ereader and I noticed that the screen is infrared and not capacitive as my Kindle ereader, that's why I asked.

Where can I find the data on the emissions of these led?

[meeera]

Originally Posted by newday07

thank you for your reply
What do you mean by "across the screen"?

http://ideum.com/2013/11/21/projecte...ech-is-better/

What you're worrying about is a non-problem.

[mathil]

Originally Posted by newday07

What do you mean by "across the screen"?

It means that the beam runs parallel, and not perpendicular, to the screen. The input to the screen is given when something physical interrupts the beam.
The front light works in the same way, across the screen, and that's why your eyes won't get as tired as with a LCD screen.

[newday07]

Originally Posted by meeera

http://ideum.com/2013/11/21/projecte...ech-is-better/

What you're worrying about is a non-problem.

Because if you want to read a lot the risk increases. The risk depends by the amount of infrared it emits and by the exposure time.

I understand that the infrared is not directed to the eyes, but no one has made any tests? To work so efficiently I think the emission should be high, or am I wrong?

[meeera]

Originally Posted by newday07

Because if you want to read a lot the risk increases. The risk depends by the amount of infrared it emits and by the exposure time.

The time you've spent worrying about it today is probably much more of a risk to your health. As is the time you spent walking to the car or bus outdoors, or eating a doughnut, or breathing in carpet & furniture fumes, or eating your lunch from a plastic container, or whatever other infinitesimal risks you took.

You're surrounded by radiation. Some of it is infrared. The vast, VAST majority of IR you're exposed to comes from the big ball of burning gas in the sky. Then there's light-bulbs, toasters, heat lamps, remote controls, etc etc etc.

To work so efficiently I think the emission should be high, or am I wrong?

On the contrary - if the emissions were high, there would be palpable heat.

[Ken Maltby]

You would have to be reading way too close to the screen, like your eyeball almost touching it, to intercept the path of the IR emission. IR emissions, like any other light emission, travels only in a straight line. It can be bent by refraction or reflection, but it still follows a straight line when it is no longer being bent. There is a sheet of black IR transmissive plastic that bends the IR at its edges and directs it across the screen.

Luck;
Ken

[newday07]

Originally Posted by meeera

The time you've spent worrying about it today is probably much more of a risk to your health. As is the time you spent walking to the car or bus outdoors, or eating a doughnut, or breathing in carpet & furniture fumes, or eating your lunch from a plastic container, or whatever other infinitesimal risks you took.

You're surrounded by radiation. Some of it is infrared. The vast, VAST majority of IR you're exposed to comes from the big ball of burning gas in the sky. Then there's light-bulbs, toasters, heat lamps, remote controls, etc etc etc.

Certainly, but having skin and eyes problens and suffering from headaches for the lights and climate reasons, when I read "infrared" in the ereader description I wanted to ask, since Infrared could be very harmful as far as I know.

[Ken Maltby]

Originally Posted by newday07

Certainly, but having skin and eyes problens and suffering from headaches for the lights and climate reasons, when I read "infrared" in the ereader description I wanted to ask, since Infrared could be very harmful as far as I know.

The argument could easily be made that the reduction in IR exposure that modern indoor living has created, is more harmful. Vitamin D3 is being prescribed almost routinely now.

Luck;
Ken

[newday07]

Originally Posted by Ken Maltby

The argument could easily be made that the reduction in IR exposure that modern indoor living has created, is more harmful. Vitamin D3 is being prescribed almost routinely now.

Luck;
Ken

you are wrong, ir and uv are different things. We need a few minutes of UV exposure per day to synthesize vitamin D.

[Ken Maltby]

Slightly more than half of the total energy from the Sun was eventually found to arrive on Earth in the form of infrared. If we are not outside enough for those "few minutes", then being outside for a healthy level of UV exposure would certainly involve a greater exposure to IR.

Not to mention the contribution IR makes to holding back Ice Ages.

Luck;
Ken

[DNSB]

Originally Posted by newday07

you are wrong, ir and uv are different things. We need a few minutes of UV exposure per day to synthesize vitamin D.

UV is the major worry when considering damage to your eyes. The tests that I've seen discussing IR damage to the eye were using sources with power levels well above those generated by the LEDs in an ereader's IR touch screen and with the sources aimed directly at the eye. A quick calculation based on the output of the LEDs in one touch screen model, you would get about 0.06% of the IR compared to looking directly at a 40W incandescent lamp at a distance of 5 metres. This calculation involved assuming 80% of the IR was reflected off the screen towards your eye and a reading distance of 20cm and that 50% of the energy used by an incandescent lamp is emitted in the IR-A and IR-B area. I could find no real numbers of how much of the IR from a IR touch screen is reflected off the screen so did a wild eyed assumption for the 80% reflectance (well above the 44% for an eInk Carta screen).

So while you are getting that UV exposure each day, make sure you are wearing a good pair of UV opaque sunglasses.

[frostschutz]

The touchscreen IR is not always-on (it's a protocol of on-off) and entirely too weak to be visible. For most IR applications you can "see" it with a digital camera (e.g. Wii Sensor Bar, find dozens of videos of that on youtube) but with the IR touchscreen... there's just nothing. That's also why IR touchscreen problems are so incredibly hard to pin down, no way to verify where things are going wrong. If someone managed to catch one of those ereader IR emitters doing anything on camera, I missed it.

[newday07]

Originally Posted by DNSB

UV is the major worry when considering damage to your eyes. The tests that I've seen discussing IR damage to the eye were using sources with power levels well above those generated by the LEDs in an ereader's IR touch screen and with the sources aimed directly at the eye. A quick calculation based on the output of the LEDs in one touch screen model, you would get about 0.06% of the IR compared to looking directly at a 40W incandescent lamp at a distance of 5 metres. This calculation involved assuming 80% of the IR was reflected off the screen towards your eye and a reading distance of 20cm and that 50% of the energy used by an incandescent lamp is emitted in the IR-A and IR-B area. I could find no real numbers of how much of the IR from a IR touch screen is reflected off the screen so did a wild eyed assumption for the 80% reflectance (well above the 44% for an eInk Carta screen).

So while you are getting that UV exposure each day, make sure you are wearing a good pair of UV opaque sunglasses.

How many LEDs are there in an ereader? Did you consider the exposure time?