Infrared touch screen

[meeera]

Originally Posted by DNSB

Jon, Jon, Jon... I was around then and trolling was not used in regards to cybersex. Trolls were persons who found amusement in disrupting newsgroups, messaging systems, chat rooms, games, etc. by posting inflammatory content.

Inflammatory disruption is a more recent usage, in my understanding. The original Usenet trolling was posting an amusing obviously-untrue factoid, to watch righteous correctors come out of the woodwork to shout about how wrong you were. Snopes, shadows in a vacuum, etc. The word had nothing to do with bridges and mythical creatures; it was derived from the fishing sense of the term. It was less about disruption and more about in-group markers in a network that had little or no effective moderation.

[HarryT]

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[newday07]

Thanks again for the answers!

Originally Posted by DNSB

As for the frontlight, it is distributed across the screen by light guides to give more even coverage and is intended to be reflected off the screen towards your eye.

So these guides are valid only for visible light, right?

Originally Posted by Ken Maltby

I don't see how this could be a problem, after all the greater IR exposure reflected into your eyes from paper books read in sunlight, should have your eyes already covered in cataracts. The same if you read on your device without the frontlight on, but in the sunlight. There would be much more Solar IR reflected back directly into your eyes, by the white paper or the device's substrata than any produced by the touchscreen.

Luck;
Ken

But I never read with the book under the sunlight. I understand that the rays of the LEDs are very small, but now my last curiosity is to understand if any ray reaches the eye or not. Some people say yes, others say no.

Originally Posted by Ken Maltby

IR emissions, like any other light emission, travels only in a straight line.

The difference between frontal and infrared light is visibility. I'm sorry but I can not understand why a blue light filter is needed if light "travels only in a straight line". Is it due to light guides? I've read somewhere that there is a layer of reflection in the screen, which is the most profound layer. Are they reflected by this layer?

[meeera]

Originally Posted by newday07

So these [light] guides are valid only for visible light, right?

"Valid"? I've no idea what you mean by that.

[Quoth]

The visible light LEDs are designed to give a diffuse reflection from the screen. They are only needed when reading by candle or in the dark. Normal safe lighting doesn't require them.

The IR LEDs are scanned, with about 15 vertical beams and 21 horizontal beams (on H2O). The beams ONLY illuminate across the surface. They are so weak a sensitive IR detector ABOVE the screen can't detect them. Only one beam at a time is lit!

There is zero risk.

It's not "obsolete" technology. It's actually the best technology for passive screens like eInk as resistive and capacitive screens reduce the brightness and contrast. The resistive and capacitive layers can also degrade the sharpness. The eInk advantage for reading is that only so called "retina" OLED or LCD are sharper, it's the lowest power (partly because normally it uses only ambient light and partly because it's bistable, white areas or black dots do not need refreshed at all, unlike LCD and OLED which must be refreshed fast enough to avoid flicker.) The eInk with IR sensing has the highest reading angle variation, tilting capacitive or resistive sensor screens exposes the pattern. Also the LCD requires a separate backlight and front filter, so colour and contrast shifts due to parallax error (the mono LCD behind the colour pattern). The OLED are not true LEDs, they are really amorphous electroluminescent dots and some need a phosphor to convert the colour. Both the OLED dot and the phosphor wears out faster than plasma screens and they suffer "burn in" like old green CRTS.

So for reading books eInk and IR touch is the best technology in terms of battery life, readability, lack of eye strain, viewing angle etc.

The IR touch system is very safe. IR, Resistive and Capacitive all date back to the mid 1980s. The touch screen PDAs (mono LCD) and CRT colour terminals for public interaction used all three technologies.
Of these three the Resistive is the best resolution, but needs most pressure. Capacitive is lowest resolution, but for a finger based GUI (like Apple BOUGHT in for iPhone) on backlight LCD or OLED (inherent emitters) the capacitive is fine.
The ultimate stylus based technology is the Wacom tablet. It's possible to combine it with resistive or capacitive.
Some phones have capacitive AND resistive to allow easy finger operation and handwriting.
The IR is somewhere between the capacitive and resistive (potentially) in resolution and is totally safe.

[newday07]

Originally Posted by FrustratedReader

Only one beam at a time is lit!

really? I believed that the beams were always on and then the finger pressure interrupted them. How do they really work?
This applies to all infrared screens including tolino, right?

[HarryT]

Originally Posted by newday07

really? I believed that the beams were always on and then the finger pressure interrupted them. How do they really work?
This applies to all infrared screens including tolino, right?

It activates them one at a time in a cycle, a bit like the scan line on an old CRT TV. Uses a lot less power that way.

[newday07]

Originally Posted by HarryT

It activates them one at a time in a cycle, a bit like the scan line on an old CRT TV. Uses a lot less power that way.

Thanks.

Originally Posted by meeera

"Valid"? I've no idea what you mean by that.

In the sense "it also applies to". I don't speak English so I help with translators and dictionary to read and write

Originally Posted by FrustratedReader

It's not "obsolete" technology.

I had read that the capacitive are far superior as false positives and that their average life is far superior. And for that the infrared has now been overcome by capacitive.

[HarryT]

Originally Posted by newday07

I had read that the capacitive are far superior as false positives and that their average life is far superior. And for that the infrared has now been overcome by capacitive.

It comes down to personal taste. I personally prefer capacitive touchscreens, because a device with a capacitive touchscreen can have a screen that's flush with the bezel, which I like. A device with an IR touchscreen has to have a bezel raised above the screen, so the IR emitters and receivers can be in the edge of the bezel. I find such a screen much more difficult to keep clean; dirt tends to get trapped in the edges.

[meeera]

Originally Posted by HarryT

It comes down to personal taste. I personally prefer capacitive touchscreens, because a device with a capacitive touchscreen can have a screen that's flush with the bezel, which I like. A device with an IR touchscreen has to have a bezel raised above the screen, so the IR emitters and receivers can be in the edge of the bezel. I find such a screen much more difficult to keep clean; dirt tends to get trapped in the edges.

If mine gets really dirty, I just run it under the tap. No problems.

To the OP: why is it relevant whether the light guides conduct IR? The IR beams are, as you've been told over and over, ABOVE the display.

[newday07]

Originally Posted by HarryT

It comes down to personal taste. I personally prefer capacitive touchscreens, because a device with a capacitive touchscreen can have a screen that's flush with the bezel, which I like. A device with an IR touchscreen has to have a bezel raised above the screen, so the IR emitters and receivers can be in the edge of the bezel. I find such a screen much more difficult to keep clean; dirt tends to get trapped in the edges.

Even the market thinks it so, because all new models are capacitive. Those who continue to put infrared screens do it because they cost less.

Originally Posted by meeera

To the OP: why is it relevant whether the light guides conduct IR? The IR beams are, as you've been told over and over, ABOVE the display.

[Quoth]

Originally Posted by newday07

Even the market thinks it so, because all new models are capacitive. Those who continue to put infrared screens do it because they cost less.

No, they use capacitive because that costs less! They can now, because the eInk screen is less grey. The IR based touch gives a clearer brighter screen, but needs a taller bezel and it costs more.

1) IR needs more parts.
2) IR taller bezel (more recess to screen).
3) IR less RF interference than Capacitive.
4) IR wastes less ambient light, screen brighter than Capacitive
5) Wider viewing angle.
6) Both are equally safe.

[DNSB]

Originally Posted by newday07

really? I believed that the beams were always on and then the finger pressure interrupted them. How do they really work?
This applies to all infrared screens including tolino, right?

Sheesh... didn't you read my earlier reply to you? Where I mentioned scanning the screen? Reducing power? To quote myself:

Originally Posted by DNSB

For the only IR touch screen I dismantled, the number of LEDs did not matter since only two were on at any one time. It used a matrix array in which the LEDs were not on continuously which increases the LED lifespan while reducing the power consumption (the latter being very important to an ereader). The pattern seemed to be turning on a vertical LED and then scanning by sequentially pulsing the horizontal LEDs. Move to the next vertical LED and loop until an event is seen.

[Ripplinger]

Originally Posted by FrustratedReader

No, they use capacitive because that costs less! They can now, because the eInk screen is less grey. The IR based touch gives a clearer brighter screen, but needs a taller bezel and it costs more.

1) IR needs more parts.
2) IR taller bezel (more recess to screen).
3) IR less RF interference than Capacitive.
4) IR wastes less ambient light, screen brighter than Capacitive
5) Wider viewing angle.
6) Both are equally safe.

I'm stuck with capacitive phones and tablets because there is no other choice, and they work relatively well enough for me since I don't read on either nor use them outdoors (phone only when necessary).

But for an ereader, I insist on IR screens only, I'll never own a capacitive reader. One reason is that my skin doesn't always play nice with capacitive so I can have a really hard time turning the pages. And the main reason is that I read outdoors and on trains, buses, etc, in temps anywhere from 0°-100°F, which means during 3 seasons I'm wearing some type of gloves. I'm not about to also have to buy special gloves in different weights that aren't as warm just to be able to read. They also usually have just a forefinger with the conductive material, and I hardly use that to turn a page. So again, it would really be a pain for me to use those gloves even if I was willing to spend the money on them. I also prefer the slightly recessed screen that IR gives you, I don't like the completely flat screen usually on ereaders with capacitive touch.

As HarryT already said, it's a personal preference. Infrared is not inferior to capacitive. It's just a different technology that some people have their own reasons for preferring.

[JSWolf]

Originally Posted by DNSB

Jon, Jon, Jon... I was around then and trolling was not used in regards to cybersex. Trolls were persons who found amusement in disrupting newsgroups, messaging systems, chat rooms, games, etc. by posting inflammatory content.

I was around before then (I logged into the very first BBS in the US) and trolls were the ones in chatrooms looking for cybersex. I was on the net before the net was public. So yes, I know what the definition of trolling is. Just because someone decided he or she wanted to change the definition does not make it changed.