A mix of questions on the CRT. Also, why didn’t we all have flat screens by 1990?
The conventional TV is mostly just a CRT, right? A CRT needs to warm up, doesn’t it? So, how does the “instant on” feature work? Or, to the contrary, why do my CRT monitors at work need to warm up before coming on? Isn’t a PC monitor the same technology as the TV’s CRT?
Bonus Round: a) Why does my 1990’s model TV (w/ conventional CRT) give off a huge flash when I turn it off? Yet, a larger TV (virtually same model with larger screen) turns off very peacefully, so to say.
b) And, if laptaps have been around for so long now, couldn’t we all have had flat screens for our desktop PCs and TVs maybe a score ago???
We could have had flat screens in the Bronze Age, if someone had manufactured them - there isn’t some universal threshold we had to cross before it was physically possible to make them. They appeared in laptops for quite a time before they were cheap and widely available for desktops, but consider; those laptops often had poor display resolution (typically 800 x 600 - sometimes less), poor contrast/brightness/saturation, pitifully slow refresh speed - the quality was only tolerated because it was a laptop. Also, they were damned expensive, which was part of the reason why laptops were always expensive.
As technology improved and it became possible to build bigger, brighter, faster flat panel displays, the market started to snowball and economies of scale, more efficient manufacturing techniques, etc. drove the price down - laptops started becoming affordable in parallel with affordable desktop flat panel displays.
This used to be a huge power-waster as well. Back in the days when a TV had a few dozen vacuum tubes inside, the instant-on feature worked by keeping the tube filaments on at about 50% power all the time. When the set was turned on, the rest of the power supply was activated and the set came to life quickly.
As for the flash when you turn the TV off, that’s just the timing of when the scan and sweep circuits shut down vs when the electron guns shut down. If the guns still have power when the other stuff goes down, the inputs and resulting “image” on the tube will be essentially random. If the manufacturer wants the set to display either nothing or a perfect picture, they’ll engineer the power supply to kill the guns before anything else goes down. Likewise at turn-on, the guns won’t come on until all the other circuits have stabilized.
It has taken us (by us I mean TV manufacturers) some time to come up with a manufacturing process for larger LCD screen sizes. To make a lot of them quickly and cheaply is a seperate issue than creating a couple to show off. And the larger the screen size, the more difficult it is. So it may have been possible to get a 14 inch flat screen TV in 1990, but back then the sizes you see now (47-60 inch) would have had a 5 or maybe 6 digit price tag.
There have historically been lots of problems with LCD manufacture. One of the big ones is dead pixels–bad enough for a pixel to be dead, but even worse if it’s stuck on a single color. Other problems abound with LCDs. The blacks, for instance, are generally worse on a LCD. The small sizes that were possible in the past (the smaller the screen, the fewer the pixels, the less the chance of dead pixels) had limited viewing angles. They are stuck with a native resolution–it’s only recently that this native resolution is much higher than 800x600. Again, it’s a question of the pixel count and the manufacturing limitations. Refresh is still slower than a CRT. The colors are often slightly off.
Have LCDs gotten better in the last 5 years? Yes, but I still don’t like them and these are all reasons I still refuse to buy a LCD for my desktop. I want to go dual-monitor at some point and I’d still rather have a 21 or 23" CRT than a similarly sized LCD. The colors are true, the blacks are better, the lack of a native resolution makes it easier to play old games, the quicker refresh rate makes it easier to play FPSes and other quick-action games, and there’s no viewing-angle limitation.