LCD H - Lin ...?

Little bit OT in that it's not any item that's on my bench, or ever will be ...

Just returned from a trip across the pond, and the return aircraft was a B-767 - the crappy dash 200 model with overhead screens. The large screen which was on the bulkhead a few rows in front of me, and which I believe was an LCD not a plaz, had real horizontal linearity issues at the lefthand side. Nothing 'sharp' or 'digital' as you might expect with LCD display technology, but a smoothly worsening error, the further you got to the lefthand side. By about a quarter of the way across, the lin was normal, and remained so across the rest of the screen. The best way to describe it is that it looked exactly as a CRT set would, if someone had mis-set the H-linearity coil.

Now I've been involved with LCD TV sets and monitors since they were first out, and I can't ever remember seeing one with this sort of effect. Saddo that I am, I have been wracking my brains to try to figure out just how this could even occur.

Anyone else ever seen this effect on an LCD display, or have any thoughts on how it could occur ?

Arfa

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Arfa Daily
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Might the screen have been an LCD, or a CRT, which "bounces" the image onto a translucent display screen via a mirror or lens arrangement of some sort? All sort of opportunity for linearity and misalignment issues with that sort of arrangement.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
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Reply to
Dave Platt

No evidence of any kind of 'line structure' on the display Dave, so I don't think that it was any kind of CRT display, direct or indirect. It was just a typical flat panel display on a bulkhead wall, the other side of which was a toilet. As well as these main bulkhead displays (there were several throughout the length of the aircraft) there were also 'repeater' displays suspended from the cabin ceiling at regular intervals over the left and right aisles. These were definitely small LCDs and were perfectly linear in both axes, which rules out there being any intrinsic non linearity in the original picture before it was placed on whatever media was used onboard the aircraft. It's a strange one, for sure ...

Arfa

Reply to
Arfa Daily

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I have seen this, and stranger effects, in LCD sets. For instance, I've seen the image "fold-over" on the right side of the screen as if it's hitting the inside of the CRT, but much more subtly, confined to about 1/4" of the picture. I always figured it was some sort of phenomenon arising from the A-to-D of the analog input signal, but I don't even know if that's possible. I'd also be interested in hearing what others think of this.

Reply to
stickyfox

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Reply to
hrhofmann

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Was only the one bulkhead display non-linear? Did you get a chance to see the bulkhead display on the other side of the plane? I've traveled a lot over the years and seen minor non-linearity, but all the LCD displays were always equal and so it was the source. LCD's should by their very nature be linear unless the digital electronics are "counting" wrong.

Reply to
hrhofmann

Was only the one bulkhead display non-linear? Did you get a chance to see the bulkhead display on the other side of the plane? I've traveled a lot over the years and seen minor non-linearity, but all the LCD displays were always equal and so it was the source. LCD's should by their very nature be linear unless the digital electronics are "counting" wrong.

My thoughts exactly, Bob, which is why I am having so much trouble getting my head around this one. As to other displays being like it, there was only one more bulkhead one in front of me, right at the front of the cabin just before business class, and then there was another in there with them, which I couldn't see - remember that this was a crappy little 767 that Delta had put on in place of the wide-bodied plane that we should have been on, and which would have had individual seatback LCDs. The 767 has a 2 - 3 - 2 seat configuration, so only large bulkhead displays up the middle. (In defence of the aircraft though, I have to say that it was very quick - 7hrs 22m across the Atlantic - and the leather seats were very comfortable). Anyways, the display right at the front wasn't close enough to see in detail, but the repeater screens over the aisles certainly were, and as I think I said elsewhere, these were perfectly linear in both axes, which I feel eliminates the source signal as being in error in any way.

Arfa

Reply to
Arfa Daily

"Arfa Daily" wrote in news:keWCm.55117$ snipped-for-privacy@newsfe28.ams:

I think you're right about the analog signal processing being the source of the problem. Any digital problem would be severe and highly noticeable.

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Jim Yanik
jyanik
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Jim Yanik

My Olevia 32" has a 'panoramic' setting that makes it look as you desribe but on both sides.

Reply to
Meat Plow

My mother's widescreen Panasonic CRT set had a 'nonsense' mode like this, as well. It used to switch itself to it automatically on such things as sports events, so you would get a sort of 'underwater' effect as the camera panned across a football field following the ball, or track runners that went from Stan to Olly as they progressed across the screen. I wonder why manufacturers put rubbish modes like this on their sets ?Did someone at Pan actually come up with this crappy idea, and think that it looked ok ? And worse, did his team supervisor actually sign off on it ?

Arfa

Reply to
Arfa Daily

Wow that would be annoying to have it switch on automatically. I hate it and it would drive me even more crazy to watch it in that mode.

One annoying thing mine does is forget its power on/off LED setting. I don't care to see it when the set is on and certainly not when its off since it is in my bedroom and is very bright. Bar getting into the setup and turning it back off almost every other time the set is on I'm ready to cover it with some black tape. I'm sure a firmware update would fix it and there's a USB port for it but alas Syntax Brillian filed for Chapter 11 on On July 8, 2008 and its assetts including the Olevia name were purchased by Emerson Radio....heh. So I guess I'm screwed and if anything major happens, it will be on the trash truck next time it comes by. (unless you might have some info on where to turn)

Reply to
Meat Plow

Black tape sounds good to me ... :-)

Arfa

Reply to
Arfa Daily

Jeez, thanks man...

I guess I'll cross my fingers and /hope/ that nothing happens to this thing. I actually blackened out the LED strip on the Olevia with a black Sharpie like I did on my LG PC monitor's blue on indicator.

Good thing is the Olevia doesn't get used much because when I head for the bedroom it's usually time to retire for the evening. I usually set the off timer for a couple hours and often wake up in my reclining leather office chair with my feet up on a stool and the set off. :-p

Reply to
Meat Plow

It's a wonder no one has invented a watchdog device that can tune in on the comatose state of a human and kill surrounding powered equipment as necessary. Think of the energy saving over a timer.

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Adrian C
Reply to
Adrian C

Well they do have a warning system that alerts a driver that he/she is nodding off while driving.

Reply to
Meat Plow

An IR motion sensor would probably work for that.

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    W
  . | ,. w ,   "Some people are alive only because
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Bob Larter

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