13 ms·
As a historical note, the bouncing logo wasn't just for fun, but was important to prevent screen burn-in on CRTs. If you had a static image on a CRT for a long
by kens 7y ago
As a historical note, the bouncing logo wasn't just for fun, but was important to prevent screen burn-in on CRTs. If you had a static image on a CRT for a long time, it could damage the phosphor. Sometimes you could even see the image when the screen was off!
This was the original purpose of screensavers, which saved your screen from damage. Displaying a dynamic image prevented one part of the screen from being overused.
- MayeulC 7y agoAs 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 agoWaterloo 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?
- hadlock 7y agoThat you feel the need to inform us of this "historical fact" makes me feel especially old... having lived through the CRT -> LCD transition period when buying an LCD made going to LAN parties a lot easier
- fred_is_fred 7y agoIt didn't even occur to me that this would need to be explained. Up next we should talk about why it was bad to leave VCRs paused for long periods of time.
- cpach 7y agoWhy was that bad?
- jannes 7y agoI believe because the tape will stay under tension
- mortenjorck 7y agoI remember being told as a child that it "wears out the tape," but I'm going to guess it's specifically because the same section of tape stays wrapped around the capstan (the metal cylinder it loops around to be read) when it would normally be passing through. Keeping the same section of tape under tension for a prolonged period presumably weakens or risks distorting it.
- deleted 7y ago[deleted]
- kozak 7y agoIt was worse than that. The head drum continued to spin throughout the entire duration of the pause, rubbing against the film at high speed. That's because the VCR didn't have any "memory" to hold the entire frame¹, so the lines of the frame had to be read from the tape over and over again. ¹ It was actually an interlaced field, not a frame, but that too much nitpicking.
- katzgrau 7y agoJust following this thread to see if anyone here thought screensavers were just for fun :)
- cardiffspaceman 7y agoAfter Dark's "flying toasters" weren't just to prevent burn-in on your Trinitron.
- edoceo 7y agoXscreensaver has BSOD mode, with all these different error screens. And a toasters clone :)
- ChrisMarshallNY 7y agoAnybody remember Todd Rundgren’s Utopia Softworks? They were going to redesign the Apple operating system, and started with the screensaver. It was a very cool screensaver, but I’m not sure how much progress they made beyond that.
- Arbalest 7y agoDVD was also popular around the time that Plasmas were being introduced, which also had burn in issues.
- tunnuz 7y agoAren’t DVDs popular anymore?
- chungy 7y agoBlu-ray has been around for a good while now.
- mattnewton 7y agoAnd broadband adoption. I think streaming actually killed it, not a higher resolution format.
- frosted-flakes 7y agoDoesn't Blu-ray still have better quality than most streaming services?
- function_seven 7y agoIt does. I’m sure most people don’t think the quality difference is worth the hassle of storing physical discs and paying for them. Compressed 1080 is good enough.
- hunter2_ 7y agoA decent number of streaming services have very good 4K and all you need is a Chromecast Ultra with a $200 TV to make it all work.
- PunksATawnyFill 7y ago
- hkiely 7y agoThis is key.
- deleted 7y ago[deleted]
- andrepd 7y agoAfter CRTs, Plasmas had issues with burn in at least.
- deleted 7y ago[deleted]
- deleted 7y ago[deleted]
- nikkwong 7y agoI 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 agoThose pixels are off.
- hunter2_ 7y agoTo 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 agoThere was a video going around of the logo hitting the corner perfect and a room full of people got real excited
- exikyut 7y agoIf 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 agohttps://www.youtube.com/watch?v=QOtuX0jL85Y https://www.youtube.com/watch?v=QOtuX0jL85Y
- Polylactic_acid 7y agoIt 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.
- jordanbeiber 7y agoTrue for any flat screen panel as well. The plasmas are really prone to ”ghosting” - just a matter of minutes. And there are ”washing” programs to ”reset” the panel. I guess plasma is the main reason why on-screen channel logos went from solid to translucent?
- jaywalk 7y agoWhat channel logos have gone from solid to translucent?
- jordanbeiber 7y agoNot the actual logos but the ones you see on-screen when watching a channel/stream.
- segfaultbuserr 7y agoIronically, the increased popularity of OLED displays in television, computer and smartphone screens has brought this problem back. If this trend continues, perhaps those 3D maze, tubes, fish, will come back to everyone's computers soon.
- Tepix 7y agoLet's hope we just stick to black screens to save some power and prevent burn-in at the same time.
- segfaultbuserr 7y agoWhy didn't we do this back in the CRT era, and invented screensaver instead, then? TV is understandable, you don't want a DVD player to show a black screen, otherwise it appears dead. But what about screensavers on computers, why did it come into being? (I know turning a CRT on takes time, but we don't have to turn it off completely to blank the screen either?) Update: It appears that the original motivation was public terminals/machines.
- dmos62 7y agoSpinning up and down a CRT reduced its life-span, I wager.
- segfaultbuserr 7y agoI don't think it was a major concern. First, you can always display a dummy black image without turning off the CRT. Also, VESA defines two "off" modes in DPMS (1993): blank and fully off. "Blank" allows the monitor to partially suspend without shutting down the CRT completely, which allows an instant recovery.
- dmos62 7y agoMight as well have an animation, as opposed to "black light"?
- sam0x17 7y agoAnd is now important again with the advent of OLED. Those things can burn in so bad.
- jksmith 7y agoI always wanted to do a theme for AfterDark involving spinning mummies unwrapping as they floated across the screen.
- WhyNotHugo 7y agoI really wish modern vendors would stop shipping screensavers -- or at least refuse to disable them on non-CRT monitors. The energy waste, battery degradation, and keeping the CPU/GPU awake longer are all huge wastes. Sadly, screensavers are nothing but wasteful nowadays.
- sitkack 7y agoOne could make an HDMI screensaver (blanker) out of an HDMI buffer chip!
- EamonnMR 7y agoI remember the login screen burned into every Mac G3 at my school.