Thanks Meter 13
Join Date: Feb 2011
Location: San Francisco, CA
This is more info then you're asking for, but CRT stands for Cathode Ray Tube. Any TV or Monitor that's not a flat screen (which is making me feel really old all of a sudden) used vacuum tubes and scanlines instead of individual pixels, and these tubes needed to be warmed up before they could turn on. That's why on older TVs you'd often turn them on, hear the sound, and then the picture would slowly fade in from black. When you turn them off, then, the picture kind of zaps out of existence, because it's an analog signal, instead of any LED or LCD screen, where all of the pixels are shut off instantaneously. The CRT animation mimicks that effect when you turn the display off on the phone.
Unrelated sidenote: How fun was degaussing CRT computer monitors? I remember I would wait weeks at a time to get a whole lot of magnetic buildup, and then when I finally hit the button and the picture shuddered back to life, I thought it was the coolest thing in the world.