4 ms·

I had heard of this before, but didn't know that screensavers were designed to prevent that damage from happening. In this case, the bouncing DVD logo seems lik

I had heard of this before, but didn't know that screensavers were designed to prevent that damage from happening. In this case, the bouncing DVD logo seems like an odd choice, as the way it's designed, there are certain pixels on the screen that it will never cross (corners, for example), which would fail to serve the desired purpose. Can someone explain?

anyfoo 7y ago
Those pixels are off.
- hunter2_ 7y ago
  To expand on this: off is perfect, off most of the time is wonderful, on and changing is great, on and unchanging is bad. So yes, you ideally want equal usage all around but you're splitting hairs between perfect and wonderful with the bouncing DVD logo's coverage.
edoceo 7y ago
There was a video going around of the logo hitting the corner perfect and a room full of people got real excited
- exikyut 7y ago
  If you look really really carefully at that video, when the camera shakes around you can see where the motion tracking for the logo overlay loses it a bit. Sorry. (Someone should do a better version.) Edit: https://news.ycombinator.com/item?id=22882947 https://news.ycombinator.com/item?id=22882947
- speakeron 7y ago
  https://www.youtube.com/watch?v=QOtuX0jL85Y https://www.youtube.com/watch?v=QOtuX0jL85Y
Polylactic_acid 7y ago
It doesn't have to cross them. Showing a black screen won't burn it in. The problem is illuminated areas that stay that way for too long. The dvd logo itself just can't be in the same spot. They probably could have just had the tv turn off/show nothing. Maybe it would have confused users not knowing that the tv was still on.
dspillett 7y ago
> Can someone explain? A CRT screen basically works by firing electrons (or if you want that a bit more scaremongery: a beam of beta radiation) at the phosphor plate, the impact of which makes it emit light. Shades are achieved by varying the intensity of the electron beam and colour is formed by having three different colours of phosphor dot and three beams (and a grid to make sure the right dots were hit by the right electrons), but these details are irrelevant to the burn-in problem. See https://en.wikipedia.org/wiki/Cathode-ray_tube https://en.wikipedia.org/wiki/Cathode-ray_tube for a longer and better explanation of how it works, and the history of the technology. Under normal operation this is mostly all fine: the phosphor "recovers" once the beam stops hitting it for a while. The phosphor does degrade (essentially they burn) a little over time with use which is also fine if the wear is level, though it does mean the screen effectively fades a little with age. If you leave a particular image on screen for a long time then it becomes more of a problem because the lit areas degrade and the unlit ones don't. Essentially the phosphor plate develops permanent tan lines. It was not uncommon to see the shadow of login prompts or semi-permanent UI elements burned into screens this way. It happens to other screen types too, though for slightly different reasons in each case. Plasma screens are particularly sensitive to the problem, but it can affect LCD displays too (some types worse than others). See https://en.wikipedia.org/wiki/Screen_burn-in https://en.wikipedia.org/wiki/Screen_burn-in for examples and a bit more detail. The earliest screen-savers were just turned the screen black. This could lead to machine being powered off accidentally (potentially losing work if a user had walked off without saving) when someone thinks they are off and tries to turn them on, so instead a simple moving message was added, the message to indicate the machine is intentionally on and the movement to stop the message burning in. Other animations were added, with After Dark's iconic flying toasters appearing in ~89, and around the Windows 3.x era it exploded and almost became an art form (anyone else fondly remember the three-and-two-tenths flying toaster brigade, or Johnny Cast-Away?), some people competed to have the best screen-saver, or just the most "them" screensaver along with wallpaper/colour-scheme/other-desktop-customisations, and of course every corporate desktop carried the (bouncing) company branding when idle. Things died down when we became more energy conscious: going back to black screens because turning the whole apparatus off when idle saves energy.

anyfoo 7y ago

Those pixels are off.

hunter2_ 7y ago
To expand on this: off is perfect, off most of the time is wonderful, on and changing is great, on and unchanging is bad. So yes, you ideally want equal usage all around but you're splitting hairs between perfect and wonderful with the bouncing DVD logo's coverage.

edoceo 7y ago

There was a video going around of the logo hitting the corner perfect and a room full of people got real excited

exikyut 7y ago
If you look really really carefully at that video, when the camera shakes around you can see where the motion tracking for the logo overlay loses it a bit. Sorry. (Someone should do a better version.) Edit: https://news.ycombinator.com/item?id=22882947 https://news.ycombinator.com/item?id=22882947
speakeron 7y ago
https://www.youtube.com/watch?v=QOtuX0jL85Y https://www.youtube.com/watch?v=QOtuX0jL85Y

Polylactic_acid 7y ago

It doesn't have to cross them. Showing a black screen won't burn it in. The problem is illuminated areas that stay that way for too long. The dvd logo itself just can't be in the same spot. They probably could have just had the tv turn off/show nothing. Maybe it would have confused users not knowing that the tv was still on.

dspillett 7y ago

> Can someone explain? A CRT screen basically works by firing electrons (or if you want that a bit more scaremongery: a beam of beta radiation) at the phosphor plate, the impact of which makes it emit light. Shades are achieved by varying the intensity of the electron beam and colour is formed by having three different colours of phosphor dot and three beams (and a grid to make sure the right dots were hit by the right electrons), but these details are irrelevant to the burn-in problem. See https://en.wikipedia.org/wiki/Cathode-ray_tube https://en.wikipedia.org/wiki/Cathode-ray_tube for a longer and better explanation of how it works, and the history of the technology. Under normal operation this is mostly all fine: the phosphor "recovers" once the beam stops hitting it for a while. The phosphor does degrade (essentially they burn) a little over time with use which is also fine if the wear is level, though it does mean the screen effectively fades a little with age. If you leave a particular image on screen for a long time then it becomes more of a problem because the lit areas degrade and the unlit ones don't. Essentially the phosphor plate develops permanent tan lines. It was not uncommon to see the shadow of login prompts or semi-permanent UI elements burned into screens this way. It happens to other screen types too, though for slightly different reasons in each case. Plasma screens are particularly sensitive to the problem, but it can affect LCD displays too (some types worse than others). See https://en.wikipedia.org/wiki/Screen_burn-in https://en.wikipedia.org/wiki/Screen_burn-in for examples and a bit more detail. The earliest screen-savers were just turned the screen black. This could lead to machine being powered off accidentally (potentially losing work if a user had walked off without saving) when someone thinks they are off and tries to turn them on, so instead a simple moving message was added, the message to indicate the machine is intentionally on and the movement to stop the message burning in. Other animations were added, with After Dark's iconic flying toasters appearing in ~89, and around the Windows 3.x era it exploded and almost became an art form (anyone else fondly remember the three-and-two-tenths flying toaster brigade, or Johnny Cast-Away?), some people competed to have the best screen-saver, or just the most "them" screensaver along with wallpaper/colour-scheme/other-desktop-customisations, and of course every corporate desktop carried the (bouncing) company branding when idle. Things died down when we became more energy conscious: going back to black screens because turning the whole apparatus off when idle saves energy.