Do backlights get dimmer over time?

[j0nblayz]

hey guys, jus wondering, does the backlight on our clies get darker and dimmer over time? cuz i bought a used NR70 and first thing i noticed was that its kinda darker and dimmer then my T665, is this normal? does this mean the nr70 has been used for a very long time?

[n2ifp]

I believe it's possible, but I haven't noticed anything. Two of each here at this location, N760C, NX70's, & NR70's, have exhibited no darkening that's obvious. The display should have at least a 10,000 hour lifespan.

[j0nblayz]

hmm.. weird, you think mines defective? anyone know if its possible to change the backlight from a t665 on to a nr70?

[NakMan]

j0nblayz,

Backlights DEFINITELY lose brightness over time, but it's hard to notice because it's so gradual.

NakMan

[OcellNuri]

I noticed that my 615 was getting dimmer. Though I'm not sure if it was really getting dimmer, or if it was just because all of the new units had much brighter screens.

[NX70BOY]

My NR of 8 months (since beginning of October) looks as bright as ever. If NakMan is right, it must be VERY gradual. But that is something to think about since I'm gonna buy a used NX70V.

[j0nblayz]

the backlight on the our clies, is it part of the LCD? or is it a different component from the LCD? i'm asking becuase i'm wondering if the backlight is something that can be replaced without replacing the screen, and if it is replacable, you guys think the backlight from my t665 will fit in the nr70?

[NX70BOY]

Even if it is a different componant, it would be 320 x 320, not 320 x 480, right? In other words, everything would be lit up (If it is even possible) except the VG area.

[j0nblayz]

i dont think you understand how the backlight works, it usually is a set of LED's lines up on the bottom and when its lit, the leds are reflected thru the LCD, well that the things, not sure bout NR70's but i have changed plenty of backlights for cell phones, so i was wondering if the same applied for NR70 LCD's.. is the backlight jus leds? will it be that hard to change the leds from the t665 to nr70? anyone have pictures on how to open up the t665 and the nr70? thanx

[NakMan]

If you guys are right, and the backlights are LEDs on these small displays, then there will be virtually no lifetime issues with them.

Large LCD flat panels don't use LEDs but very small diameter fluorescent tubes and these are the things that get dimmer with use.

I'm sure this has to do with LEDs being "point sources" as opposed to "line sources" like the tubes. It's far easier to diffuse a line source to get the entire display evenly lit than multiple point sources. Also, "white" LEDs tend to be on the bluish side and you have to hand select them to get the proper color temperature - this costs time and money.

I assumed that the backlights were fluorescent due to the high power consumption with them on full brightness (you need an inverter to create the high voltage for the fluorescent tubes). I can't believe that LED backlights would need anywhere near the current.

NakMan