Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

[Paul678]

Excuse me for the newbie realization, but I just
took apart the Komodo 42" LCD, and there was nothing
between this ultra thin piece of LCD glass, and
the wild, baseball throwing kids of the world! Same
goes for the other LCD I worked on.

And both the plasmas I've worked on had very thick glass
over them, even the older one.

Is it just cost reduction, or is it a weight issue, where
the LCD makers are targeting people who mount them
on the walls, or hang them from the ceiling?

Or perhaps they WANT you to break them quickly, so
you'll buy next year's model sooner! haha

[shovenose]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

These are all just guesses, but I think they just want to save money, also, maybe o,age quality gets worse, or brightness?

[Paul678]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

These are all just guesses, but I think they just want to save money, also, maybe o,age quality gets worse, or brightness?

Perhaps a combo platter of all the above.

Someone mentioned how you sometimes cannot really see a cracked
screen. I didn't take it seriously, because the first cracked screen
I got was very obviously smashed up. But after today, I'm thinking
I got lucky the Insignia 32" I easily fixed wasn't cracked.

So there's no real way to see these cracks if the lamps aren't lit?

What about hair-lined-cracked plasmas, with all the gas leaked out? No
way to tell if the buffers/y-sus aren't working, right?

[Scenic]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

So there's no real way to see these cracks if the lamps aren't lit?

It helps to inspect the panel with a really bright LED flashlight/torch close to it at a bit of an angle.

Someone tried to scam me once saying it (32" LCD) just doesn't turn on anymore, but otherwise it was fine up to that point . Went hunting with the LED flashlight and found a diagonal crack in a top corner. You couldn't see it at all without the flashlight. Confronting him with that made him admit it fell over at some point. He probably "modified" it to get no AC power so the buyer couldn't check for cracks.. damn idiots

[tom66]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

Several reasons:
- LCDs do not contain a gas so glass is not needed to maintain this pressure. (Plasma panels deal with 4 Torr, which is a huge amount of pressure, so the glass needs to be quite thick.)
- Newer plasmas are foregoing this thicker glass to make thinner and lighter TVs. The picture is brighter as a result of this, but the glass is far more prone to cracking.
- Glass is expensive.

I *have* see one display with a second layer of glass over the main screen, on a Panasonic plasma. The screen was about 8mm back from the main glass, which was a good few mm thick. Panasonic directly marketed this glass as being replaceable if damaged by flying game controllers.

[Paul678]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

I'm not talking about the thickness of the panel itself, for which
plasma would definitely be thicker than LCD for the reasons you have stated.

I'm talking about the additional piece of glass that covers the actual
panel. This additional piece of glass was there on 2 plasmas, and
was missing on 2 LCDs.

I think it's a combo of cost and weight....especially since the viewing
areas are getting so large.....they have to do something to keep
the weight down.....

[tom66]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

I'm talking about the additional piece of glass that covers the actual
panel. This additional piece of glass was there on 2 plasmas, and
was missing on 2 LCDs.

It's probably because if the main glass broke, it could easily shatter and hurt someone.

Or because plasmas are not intended to be super thin TVs.

Or because plasmas used to be very expensive, and still cost more than LCDs.

[PlainBill]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

And to add two more reasons,
1. A protective glass layer would provide two more surfaces to scatter light, get dirty, and cause double images. I believe it was in this forum someone had a problem with a plasma TV that had a blurry picture, but mainly in one area of the screen. He eventually discovered the TV had a second EMI absorbing layer of glass. Cigarette smoke residue had coated the surfaces. Fortunately, he was able to dismantle the TV, remove the front glass and clean both surfaces. But what a pain if that had to be done routinely!!

2. Glass absorbs light, making the picture dimmer.

PlainBill

[Scenic]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

why do I keep thinking of plexiglas now that I rethink the concept of having a protective whatever in front of the LCD.. ?

Wouldn't shatter into a million pieces, it's rather light and can be very sturdy.. hmm..

[PlainBill]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

why do I keep thinking of plexiglas now that I rethink the concept of having a protective whatever in front of the LCD.. ?

Wouldn't shatter into a million pieces, it's rather light and can be very sturdy.. hmm..

And attracts dust, and scuffs easily.

PlainBill

[Paul678]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

Yeah, most "plasma vs. LCD" websites give the
brightness advantage to LCD, so no doubt this
is one of the reasons.

But let me ask again: Is there a way to tell if a plasma
panel has an invisible crack, that has allowed the
gases to escape, when the Y sustain and/or buffers
are bad?

[rpgruss]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

Can't speak for all panels, but I have an LG panel here that has a glass bulb on the backside, if the panel is broken the bulb gets shattered. I can post up a picture if you want.

[Tvbob]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

Back in the day, High end lcd's such as the Olevia (lt42hvi) have a removable anti glare glass panel in front of the lcd panel. Most of the newer stuff is cheap junk.

[cliff_hootarski]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

I have one of those Olevias. I has a very thick front glass panel. The 46" LCD tv weighs in at a slim 130 lbs!

[Paul678]

Re: Why the Hell aren't LCDs Protected with thick Glass, Like Plasmas?

Can't speak for all panels, but I have an LG panel here that has a glass bulb on the backside, if the panel is broken the bulb gets shattered. I can post up a picture if you want.

I'm aware of the bulb on plasmas that you are talking about,
but I'm sure you could have a tiny crack on the front of the
panel, lose all your gas, and not affect this bulb.

And just like with LCDs, it could be very difficult to see this
crack if the panel doesn't light up......