[Ham-Computers] Do LCD monitor displays get "dingy" or faded looking?

[Hsu, Aaron (NBC Universal)]

Phil,

I've never paid attention to side-by-side comparisons over time, but I do know that (as Ron pointed out) CCFL tubes will eventually fade over time.  It's also possible that the "back side" of the panel is now covered in a thin layer of dust/dirt/grit/grunge/call-it-what-you-will that's blocking light and causing a dirty/dingy look (sorta like the outside surface of an upper story window that never gets washed).

And FYI - contrary to popular belief, LCD panels are also subject to burn-in ala CRT displays (I have one sitting in front of me as I type).  I didn't believe it was burn-in at first (thought it was some type of grunge as mentioned above), but with certain background screen colors, the "grunge" became faint icons - icons from my Windows desktop.  Never noticed them before because the icons were always "on top" of the burn-in.  When I relagated said monitor to "secondary" status with a black background, the burn-in icons were slightly visable.  Doing some research, I found that it *is* possible for the crystaline structure of LCD displays to want to become "permanent" the longer a static pattern is displayed.  The longer the static item is shown, the more likely it will "burn in".

Luckily, LCD burn-in is somewhat reversable - just "invert" the pattern and hope that any crystals will revert to another state.  It took about 4 months of a "black" screen until the burned-in icons disappeared from normal view, but if I bring up a "teal" background color, I can still make out some of them.  I'm sure I can quicken the restoration process with a fully white screen, but it's kinda blinding.  I really don't care too much - it's a company monitor.

One last thing (since Ron brought it up).  One of the things I specifically went to see at this year's Consumer Electronics Show (CES) was OLED's.  Small monochromatic OLED's have been available for a few years (found on higher end car stereos and cell phones), but full color OLED's have only been around for a couple years and in very small sizes (2 to 3 inches).  At last years CES, several companies showed 12 and 15 inch OLED TV prototypes, all less than 3mm thick.  At this year's CES, Samsung, LG, and Sony all had 12, 15, and 17 OLED TV prototypes and Samsung had a 26 inch model.  All were 1 to 3 millimeters thick.  LG hopes to ship the 15 and 17 inch models by the end of 2009.  Samsung doesn't expect to ship until 2010 and the 26-inch model probably not until later.  OLED yield is very low right now and the 17-inch model would cost about $2500 if available today.

Let me tell you - OLED's (Organic LED's) are simply amazing.  Take razor sharp picture clarity of today's best 120Hz LCD display, throw in the vivid color of today's best plasma display, and you have the stunning picture quality of OLED.  Today's LCD panels don't have *VIVID* colors (like plasma and DLP) and today's plasma doesn't have the "you're there" sharpness (like 120Hz LCD) - OLED's have both.  Simply amazing.  I have pictures from the show, but the pics don't do the displays justice.  I'll post them somewhere if I get a chance.  Definitely the wave of the future (give it 2 or 3 years).

Also, OLED's can be manufactured (grown) on flexible backing - last year, LG was showing an industrial prototype of a "wrap-around" display for marquees on street corners (wraps around the corner of a building).  They were also showing off drinking mug display prototypes - yes, a cup with an OLED around it.  Very cool.

Until OLED's become mainstream, expect LED backlighting for LCD's to become more common.  Until recently, a problem was the color gamut - most "white" LED's are too blue, but manufacturers are definitely getting around this problem now.  Laptops with LED backlights look great, but color accuracy is a bit off.  The power savings is definitely worth it if accurate colors is not a concern.


Anyways, just throwing in my 2 cents.

73,

  - Aaron, NN6O

p.s.  Just in case people are wondering what type of large screen TV I have at home, I have a LED driven rear-projection DLP display.  When I got it in 2007, plasma was too heavy and expensive (and sucks *MUCHO* power), and 120Hz LCD panels weren't readily available yet (and the colors weren't that great + motion blur).


-----Original Message-----
Sent: Monday, February 02, 2009 4:07 PM
Subject: Re: [Ham-Computers] Do LCD monitor displays get "dingy" or faded looking?

Unfortunately most LCD displays are "lit" by florescent lamp/s that dim with use just about the same as tungsten incandescent lamps develop a dark coating inside on the cooler parts of the envelope.

White LEDs are an eventual replacement for them, but tri-color LED screens are going to replace the LCD first.  (using organic LEDs that are printed on a sheet of plastic)

-- 
   Ron  KA4INM - Youvan's corollary:
                 Every action results in unwanted side effects.