aznxtallxboy

this morning when i started my car to go to work....i touched my screen to adjust the fan for the a/c and for some reason....it didn't work...i was like wtf... ..it was like the screen didn't sense my finger touching the screen... ...i was wondering if anyone else had a similar problem or is it just me..?

NSX-Tuner

I only had this problem once in my old '01 CLS. It had been sitting in the sun where the display got some direct sunlight. However, once I let the screen cool off after shading it, it worked fine. I just made sure from that point on that I used a windshield shade.

EricL

Funny, same thing happened to me. Twice. And, it was HOT out!

Both times I used a dab of water on a MF towel to clean the display (I keep a MF towel and some bottled water in the car). And, within a minute it was working perfectly again. Based on your comments, I would expect your "heat" explanation would make sense with the water cooling down the screen (cooling by evaporation and conduction).

Interesting!

einsatz

The 01-03 CL/TL's screen uses an IR field to detect finger position. This means when it's really hot, it can't detect your body heat since everything is hot.
The new navi systems have a plastic sheet on top of the display which is what detects the finger presses, so it's not IR-dependent.

jet-tek

besides being almost as sensitive as the chrome in our headlights (scratches)
alls good-

Sly Raskal

iTrader: (1)

I've had the same problem occasionally but not only on the AC screen.

I can't duplicate the problem on demand but the fact that it has only happened a couple times it hasn't bothered me.

I don't know the causes of the problem though. Could it be temperature, oils on finger, or some other factor?

Chaptorial

These things are very easy to scratch.

EricL

I have serious doubts about your explanation. If you have more info, I'd like to see it.

Here is a link to a IR scanning display page and the surface wave, capacitive, resistive, all have operating temperature limits that will cause the sensors to either a) fail or b) stop working until the operating temperature returns to normal. The failure is probably due to exceeding its operating range temperature limit.

The 3M resistive panels have an operating limit around 50-degrees C (122-degrees F), and the capacitive are higher at 70-degrees C (158-degrees F). It can get REALLY hot in the car.

So, the question is: is the device just operating outside of the its temp range *OR* is it really looking for the heat from a fingertip. (I guess driving gloves are definitly out -- hey?)

With people being able to operate a car with the windows open in the dessert (ambient can be 120-degrees F), the contact temp of a human finger tip, depending on lots of factors, would only be around 100-degrees F. That sure seems like a feeble design.

Here is a link that might be useful:

http://www-staff.it.uts.edu.au/~don/graphics/infra.html

NiteQwill

Don't know much about the screen on our navi, but when i face my V1 towards my screen, my laser detector goes off, sensing some type of IR field. if that means anything.

EricL

There are different wavelengths of IR (see below).

The unit is a IR scanning display. The idea is to set up a matrix of IR emitters and IR detectors (the picture shows the details). When you interrupt the beams at a given point, you get the X-position and Y-position where your finger has pushed. If you know x and y, you know exactly where you are pressing.

If your V1 goes off, there are IR emitters, and it is a standard IR scanning display (as I've described above). So, you are basically confirming that the unit does have emitters. If it didn't, your laser detector would NOT go off.

If the unit was passive, your V1 would not give a "false" laser detector reading. I get mine to "bark" by bringing out any of my IR remote controls and shining them on the V1's IR window.

There are other myriad difficulties with a passive design…

Finally, there are different kinds of IR. Near IR, mid IR, and far IR. The IR you see from buildings, humans, etc is of a different wavelength then the IR wavelength that is typically used for IR-emitters (used by laser guns, IR remotes, and IR scanning displays) and IR-detectors (generally PIN diodes with a lens/filter).

If you take a typical IR detector, it won't notice the body heat of a finger, arm, whatever. It's wavelength is around They make specialized IR detectors that are used for those lights you typically see that turn on when they sense a persons (or animals) body heat.

I believe the above is what causes some confusion to people when “IR” is used…

aznxtallxboy

hMm.....my car wasn't even hot when the problem occured...it was parked in the garage...nice and cool.....

EricL

Is you display nice and clean? (I'm talking dust free with minimal finger prints.)

See if it repeats again after you clean it.

I've only had the problem in the heat. That doesn't mean that other factors couldn't be involved.

I have been "bothered" by sloppy behavior when the screen was dirty, dusty, and/or had too many finger prints on it. It always seems to "shape-up" when it gets a gentle -- but effective -- cleaning. (Clean water and MF towel [DAMP MF TOWEL] is what I use to make mine happy.)

I don't recall it happening, but the design uses detectors. As such, and even with IR filtering, a noisy light source or a very bright light source could "swamp" the IR receivers (pin diodes, etc.) Where there any florescent lights or other non-incandescent light sources? And, finally, the sun itself has plenty of IR in its spectrum (I’m not suggesting that it’s noisy).

Here is something that may be of interest:

LINK: http://www.3mtouchmatters.com/e_article000047339.cfm

Comment:

Heat can cause the operating temps to get high enough on the display electronics to mess-up the signal-to-noise of the detectors. They are not very happy in high temps.

Dirt and debris just add to the "effective noise." It's kind of like a kind of electrical clutter. The screen has to allow for some dust and junk, but if you have enough crud around, you wouldn't want the unit to "auto select" items for you. So, if an engineer was designing the device, and had to make a choice, what would be better: Having the unit be "unresponsive" when presented with "clutter" (in the form of crud or other problems) or just start generating false finger presses?

The paragraph above is based on other designs and is only my opinion.

YMMV

einsatz

I did some searches trying to figure out where it was I read it. I couldn't find it but if I do I'll post it. Your explanation of the problem being the IR field electronics being outside the operating temp makes definite sense and may have been how what I read was originally intended to be interpreted - ie I may have misunderstood the "heat messes the IR field up" concept as "heat makes your finger invisible to IR field".
I do know the newer Acura systems have dropped the IR field for the additional layer in front of the display to detect touches since the TSX and TL both have the extra layer.

rbf351

we have the LEDs as u can see in this pic of my screen, nut not the phototransistors

aznxtallxboy

is there any way to repair the scratches or do you have to get a whole new screen?

EricL

I see some old style LEDs and/or PIN diodes (photo detectors). They both have two leads – in the non-surface mount versions – and they both look nearly identical.

I've already tried operating the unit with the end of a thin piece of cardboard, a plastic stylus from my graphics table, and they all make it work perfectly. IOW, it isn't detecting body heat (long-wave IR).

ARE you suggesting that the 5 LEDs or photodiodes that are clear and to the right of the TFT panel are the "guts" of the system (IOW, that all the active IR electronics used for the display consist of the clear two-lead non-surface-mount devices to the right)? All the units I'm aware of use an emitter and detector in an array *and* the service manual suggests the same thing. (The manual says beams. They do make combined emitter/detectors that fit in a single package, but...)

If you emit IR, but have not device to detect it, how does it work -- hey?

Here is the blurb from the 2001 CL/CLS service manual (AKA HELMS):

Page 22-313:

Have a look at the U-shaped metal channel with little slots in it at the top of the picture. It sure looks to have TEN openings -- hey? The designations start with "C" (e.g. Cxxx) and normally are used to notate caps. But, what are the ten holes for?

You would generally want the emitters and detectors as close as possible to enhance signal fidelity.

Do you mind having a closer look at the channels?

EricL

I don't know for sure. The answer – and fix -- probably depends on how deep they are...

EricL

There are some comments "around" on how it is better to move away from IR touch screens. I ran into this in regards to avionics.

I even tried a few objects just to see if someone is making "top secret" parts for Alpine. Cold objects (cardboard, stylus, even the corner of the thin users' manual got mine to work today).

Do you know what type of technology is used in the new one (Capacitive, resistive, surface wave, etc.)?