3 ms·

As to why they are not necessary anymore: we just turn the screen off (some displays, especially OLED, are still prone to burn-in). This was not necessarily wa

As to why they are not necessary anymore: we just turn the screen off (some displays, especially OLED, are still prone to burn-in). This was not necessarily wanted in OLD CRTs, where the startup sequence could take a while (and possibly other factors, such as reducing the lifespan, but I'm not sure about this). Funnily, we are starting to see a bit of a comeback of these in OLED smartphone that have an always-on display to show time and a few things: the illuminated portion generally moves over time. You can see some burn-in on old phones, in the notification areas, the taskbar for computers, or sometimes the always-on TV panels at airports or train stations.

tialaramex 7y ago
Waterloo Station (in London, named after the bridge, which is in turn named after the battle, which was in Belgium) for a while had these full colour panels which I guess may have been plasma? These were used to display train information. They suffered terrible burn-in, and I was never sure why they were used. Eventually they ripped them out and replaced them with panels using the same technology (monochrome panels made of amber LEDs) that is used in the rest of the network for displaying information. The thing about information is that you don't want it to spin or hop about, it needs to remain perfectly still while a potentially large number (tens of thousands of people use the station in an hour, if anything goes wrong all those people want information) stare at the information and so it can't avoid burn in. I can see that for the advertising screens, the opportunity for huge full colour screens is worth the risk of burning in an image, and worst case you could in theory even charge an advertiser who insists on holding a single image for the cost of repairing/ replacing your screens. But the information screens don't much benefit from colour, the pixel-addressable LED screen is only a small improvement over prior electro-mechanical devices which of course couldn't burn in, why allow burn-in just to get a colour screen? Maybe they were cheap?
- devenson 7y ago
  Just move it imperceptibly slowly.
  - exikyut 7y ago
    That only works for screen-width-length runs of text. Also, cue trainspotters and such putting 10-hour+ 1x-speed captures of the screens running through the entire cycle up on YouTube...

tialaramex 7y ago

Waterloo Station (in London, named after the bridge, which is in turn named after the battle, which was in Belgium) for a while had these full colour panels which I guess may have been plasma? These were used to display train information. They suffered terrible burn-in, and I was never sure why they were used. Eventually they ripped them out and replaced them with panels using the same technology (monochrome panels made of amber LEDs) that is used in the rest of the network for displaying information. The thing about information is that you don't want it to spin or hop about, it needs to remain perfectly still while a potentially large number (tens of thousands of people use the station in an hour, if anything goes wrong all those people want information) stare at the information and so it can't avoid burn in. I can see that for the advertising screens, the opportunity for huge full colour screens is worth the risk of burning in an image, and worst case you could in theory even charge an advertiser who insists on holding a single image for the cost of repairing/ replacing your screens. But the information screens don't much benefit from colour, the pixel-addressable LED screen is only a small improvement over prior electro-mechanical devices which of course couldn't burn in, why allow burn-in just to get a colour screen? Maybe they were cheap?

devenson 7y ago
Just move it imperceptibly slowly.
- exikyut 7y ago
  That only works for screen-width-length runs of text. Also, cue trainspotters and such putting 10-hour+ 1x-speed captures of the screens running through the entire cycle up on YouTube...