John wrote:
On May 25, 7:20 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:It's got to be good for the future, since LEDs and OLEDs are still climbing the efficiency ladder, while flourescents are just about done. But for now, LEDs have a hard time beating CCFLs in intrinsic efficiency, but they can have a more efficient power supply.FWIW: I had a CCFL circuit go bad in a Cassiopeia E-125 but I think it's the parts that drive the CCFL and not the bulb itself (at least someone who swapped parts around got their screen to light). Since LED flashlight mfgs advertize 100,000 hours of life I thought - "hey one less thing to worry about".
That's something to hope for, but bright, high-powered LEDs don't always have long lives--brightness will decay with time. But since their brightness is strongly dependent on temperature, it is often actively regulated. This would be particularly important in a tri-color backlight, since any change in LED brightness would affect color balance. That regulation *could* extend the useful life of the LED backlight relative to a CCFL, but whether it actually does depends on the life characteristics of the LEDs at the operating power level. Of course, running a display at a lower backlight brightness reduces its power and extends its life considerably, whether LED or CCFL backlit. -michael NadaNet file server for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."