26-11-2016, 11:22 AM
(This post was last modified: 26-11-2016, 11:23 AM by Mike Watterson.)
All LCDs have either CFL, CCFL or LED lighting. The cheapest are edge lit and more expensive true back lights. Very expensive ones have R, G & B LEDs and light pipes.
All use coloured filters to make the colour
All have two polarisers, so the rotating polarisation in the LCD sub pixel can be clear or dark.
The dye fades on areas that are always bright. I've seen burn in on Call centre LCD screens. If part of the screen gets sunlight the polariser and dyes will degrade!
So there is not just back light issues.
Plasma types use gas discharge and phosphors on inside of glass. A natural mono plasma panel with no phosphor lasts longer but is orange (from neon) and darkens gradually. I don't know what gas(es) are used in colour plasma, but the phosphors wear faster than CRT due to gas ions rather than electrons only. A Plasma type thus never uses a backlight.
All use coloured filters to make the colour
All have two polarisers, so the rotating polarisation in the LCD sub pixel can be clear or dark.
The dye fades on areas that are always bright. I've seen burn in on Call centre LCD screens. If part of the screen gets sunlight the polariser and dyes will degrade!
So there is not just back light issues.
Plasma types use gas discharge and phosphors on inside of glass. A natural mono plasma panel with no phosphor lasts longer but is orange (from neon) and darkens gradually. I don't know what gas(es) are used in colour plasma, but the phosphors wear faster than CRT due to gas ions rather than electrons only. A Plasma type thus never uses a backlight.
