LCD Display Questions - Longevity and Monochrome?

At about the same time, two readers sent in questions about those expensive LCD panels that, if you are not fortunate enough to own one, you are envious of anyone who does (I know I am!). However, these two questions raise some interesting issues which I'm sure those of you looking to buy one, may be asking as soon as you make that purchase. One issue is longevity: how long do those LCD pixels last? Another issue is cost: why don't LCD manufacturers make lower-cost Monochrome LCD screens available for those who don't need to work in full-color glory?

Jack Frost IV asks: "Since higher resolution LCD panels have started to become a lot more common, many people have been complaining about dead pixels. I just received two SGI flat panels direct from the factory, and each shipped with a single dead pixel. In fact, the second display was a replacement for the first (for an issue unrelated to the dead pixel). While I understand the difficulties in manufacturing the displays, the single dead pixel doesn't concern me right now, as I don't notice it often. What bothers me is how many more pixels these displays will lose during a lifetime; say over the next three to five years. I want to replace a lot of my CRTs (Yes, *some* of us don't do color critical work, and LCDs are perfectly OK) with LCD panels, but if, say, a dozen pixels are going to die in 3 - 5 years, it's going to be quite annoying. SGI claims that once the pixel burns out, you'll never notice it was gone... but I don't buy it. Can anyone explain some of the longevity and degredation issues relating to flat panels?"

O'Bunny queries: "How come nobody apparently sells monochrome LCD monitors for PC-like devices? I'd love to have a largish (say, 1600x1200) flat monitor that: doesn't weigh five thousand pounds; isn't fifteen feet thick; and doesn't cost an arm and a leg.

The rationales that I've heard behind the high costs of these monitors were:

1. The manufacturing yield is low because of the large number of transistors that need to all work properly to display colours.
2. The economy of scale currently is aimed at laptop users, for whom a 1600x1200 screen is impractically large (unless you happen to be Andre the Giant)

Ignoring the second part, why doesn't anyone make a decentmonochrome LCD monitor for those of us who want a large screen but don't necessarily need color?

In my case, I want to edit multi-channel audio. A Color display adds almost nothing to the information that I extract from the screen. I can select, cut, copy paste, apply effects, and otherwise mangle the sounds as well on a 1-bit per pixel display as I can on a 32-bpp monster.

I am also a technical writer. The documents I write are produced on a B&W laser printer, mostly. Certainly, on-line documents (and even most printed ones) can benefit from intelligent use of colour for various reasons, but most printed documents end up in black and white (mostly for cost reasons). Again, colour adds little to the experience.

So, I guess my question really comes down to the following:

• Where can I get a large monochrome flat-panel monitor for a PC?
• If I can't get one for $less than a colour flat panel, why not?"

Comments

Economies of hype

[Gray]

I suspect it's because the whole 'LCD on the desktop' industry deal is still very much a special thing for people who want a slick front office. Yes, I know people (more then average around here) use them for solving real problems when a big CRT won't do it, but I'd say at least 80% of units sold goto vanity applications. Vanity means color.

Re:Economies of hype

["Zow"]

While your point is well taken, another major advantage of LCD displays (other than the space savings as noted by another poster) is the power and cooling savings. Fred Cohen had his students in the CCD do a power and heat analysis of all their equiptment in the wake of the CA power crisis. They found that a 17" LCD monitor only drew 1/10 the power and generated 1/4 the heat of a 17" CRT monitor meaning that the higher cost for the LCD monitor would pay for itself after just a couple years of use.

-"Zow"

ISO standards for pixel fault on flat panels...

[Katchina'404]

Here's some information regarding ISO standards fro LCD's flat panels. (All this info is from technical documentation I got from Fujitsu-Siemens Computers.)

ISO standard 13406-2 is a completion of ISO 9241-3, -7 and -8, which already regarded LCD's. Classes I to IV are defined in ISO 13406-2.

Class I (theoretical) allows for no pixel faults.
Class II allows for 2 "light pixels", 2 "dark pixels" and 5 "other faults", per million pixels.
Class III allows for 5, 15 and 50 respectively.
Class IV allows for 50, 150 and 500.

"light pixel" is when a pixel is >75% lighter.
"dark pixel" is when a pixel is >75% darker (or "death", I presume).
"other fault" is, well, for other faults (e.g. a subpixel is defect, giving the pixel a distored hue - think color-stuck pixels).

Class II is considered acceptable for office use. Classes III and IV are not.

For a 1,024*768 panel, which is 786,432 pixels, that makes 1.57 light pixels (rounds up to 2), 1.57 dark pixels (rounds up to 2) and 3.93 other faults (rounds up to 4).
This give a maximal number of defective pixels of 8, which is 0.001 % of the screen surface.

This data is very useful when you're a techie on the field and you're being annoyed by some customer who keeps asking for a new monitor because his/her got one or two death pixels. You can tell the monitor still meets the industry standard and therefore will not be replaced.

As for the ViewSonic monitor, I suppose ViewSonic was pretty nice to you when they replaced your "defective" monitor.

Re:FPS in LCD?

[The Cookie Monster]

Not that the human eye needs 30 but still....

That's an urban myth.

Well, OK, you might not need more than 30 depending on what you are doing, but you can certainly see far higher than 30. You're probably being confused by motion blur. You should also ask yourself whether the concept of 'frames per second' is really applicable to how the human eye works.

What about B/W printers?

[cvd6262]

I think the idea of monochrome LCD displays is about the same as black and white printers. Let's see, one can buy a good color printer for $75-150(US). How cheap would a B/W printer be?

Yet no body sells them because they would make less money on them.

1 bit Mono?

[Alien54]

In my case, I want to edit multi-channel audio. A Color display adds almost nothing to the information that I extract from the screen. I can select, cut, copy paste, apply effects, and otherwise mangle the sounds as well on a 1-bit per pixel display as I can on a 32-bpp monster.

Actually, what you want is grey scale, not 1 bit Mono.

You can see the effect by taking any BW photo, and convert it to 1 bit color.

You also see this in printing. Laser Print IS 1 bit color, more or less, but you get true photo-grade at about 1500 dpi. Contrast this with grey scale, say on a screen, where 70 - 100 dpi is adequate for a photo, if you are using grey scale. 100 dpi in 2 bit color is horrible.

Check out the Vinny the Vampire comic strip

B&W LCD Monitors have some purpose

[Med_Geek]

The medical industry uses high-end LCD's in radiology departments. Resolution and brightness are the most important factors and you pay for it. Check out these puppies: http://www.dome.com/products/cx/cxdisplays.html

Longetivity

[thinmac]

I'm not sure how todays displays differ from those of older laptops, but I have a PowerBook 170 from almost 10 years ago that is still looking great. At the time we were extatic to have found one with no bad pixels (they were few and far between at the time), and I can say for sure that the same is true of that screen today. It should be noted, however, that that was one of the earliest shipping Active Matrix screens, and monochrome, but it would be hard to find a 10 year old Apple Cinima Display (drool) to check.

YMMV

[EricEldred]

I can only speak from my own experience:

1. Dead pixels are usually there from the beginning, so shop carefully. Later, there is the more likely possibility of having a dead streak of pixels.
2. These LCDs are produced on big assembly lines that need a lot of capital and long runs to be economical. Monochrome LCDs are being produced for small screens such as for cellular phones. Color LCD assembly lines mostly produce larger screens for such uses as portable computers and now desktop displays. Since manufacturers can make more money producing the big screens, and since the factories were built to produce big color screens, they are mostly color now. The price varies by supply and demand--both now favor color screens, which are now going down in retail price as the supply has recently been increased.
3. If you are considering an LCD display for use by a technical writer, look at the digital LCDs and not the cheaper analog variety--type will look better. The price of a 19-inch CRT monitor has gone down dramatically in the last year and might be more cost-effective for such a purpose than a digital LCD screen.