There are a couple of branches on the TV’s evolutionary tree that were dead ends.
The Early TV
Mechanical TV – it looks like a zootrope stacked vertically, and it kind of was – little holes spinning in front of a light let the light make pictures. This was an attempt at showing moving images across long ranges, and it worked surprisingly well for what it was! It couldn’t go very fast, and the kind sold to the public were generally pretty small, and the frame rate was awful so there was no watching sports or fast action on them – but they could recreate a moving image beamed to them from far away. That was slick!
Here’s a video that does a better job of explaining the mechanics of it than I can, here. The section where he discusses actual function is about 5:45 – he’s made his own as an example. This wasn’t necessarily a bad invention, it was just a dead end. There’s no way to make it show color, and there’s a maximum limit on frames per second – not to mention size! The diameter of the disk has to grow proportionally to the size of the square it’s making.
CRTs – Back On Track
Regular TV tech continues to grow, and CRTs (Cathode Ray Tubes) are invented. CRTs work by using vacuum tubes and heated tungsten, which excites electrons enough that they move. The electrons are then beamed to the screen, where they hit the phosphors responsible for displaying pictures. This is a very rough definition – that Youtube channel from above also has videos on how this works, but this is the essence of the tube. Specific images are created by modulating these flows of electrons with electrodes. This tech persists for decades before LCD and LED tech dethrones it, but it’s entirely possible to find them in thrift stores and garage sales – they’re really not that old, and they produce high quality images for their size and age.
Strange Case of the CRT Container
Casings for TVs used to be gigantic, so it’s only natural that someone would want to make that giant case decorative. Welcome to the world of weird TV bodies! Triangles, cabinets, stands designed after the old fashioned radios, bodies modeled after cruisers of the time – things got weird. Ultimately, rectangles are easier to stack and match theme-wise, so they won out, but imagine a world where the modern TV looked like it could be used as a weapon!
Squares dominate the scene for a time, before rectangles ultimately win out. Wide Screen TVs are a luxury, and not many people have them – broadcast format reflects this, even today, and most media falls within a certain aspect ratio. When it doesn’t, it keeps important information to the center of the screen, so movie theaters and the like don’t accidentally cut off context for the media. Cases get smaller and smaller, while the screen gets bigger and bigger, and eventually we hit the theoretical minimum of a quarter-inch black bar around the perimeter of the screen. It’s no longer a disguise, it’s just holding the outside screens against the inside ones. Anyway, back to the past!
Projection Screens – Oh No
Front-projection TVs – they were cool, but were subject to issues of dust. And as early owners of the 4K curved TVs also found out, sometimes sitting in the wrong spot meant visual distortion. Rear projection inside the casing of the TV solved all of these problems. Still, they were cool while they lasted, and a brilliant example of people breaking through limits with creative means – CRTs only got up to about 40”, but these could get pretty big!
Rear-projection wins over because it’s less easy to contaminate and easier to take care of, and even it has it’s issues – repairing them could get expensive because they were also pretty big, both in width and depth!
Topsy Turvy Curvy Light Shows
Las Vegas is famous for many things, and LED displays are up there among them. Gigantic panels of lights curve over the top of Fremont street, and along columns all over the strip. Curvy screens with modern lighting techniques have been experimented upon for ages. Those 4K curving TVs mentioned before are no exception – they curve inwards. Yay! What’s not so yay is that the viewing angle changes much more for someone sitting at the edge than it does for a flat screen. It’s not an enormous issue – the TVs are usually huge, so there’s a lot of places to sit in front of them that aren’t distorted.
However, the curve itself adds width to the screen, and it can leave you with the choice to either leave black bars on the edge of older movies, or widen the image – which looks strange. The TV itself still works, it’s just not ideal, and sometimes that’s enough to kick a product to the bottom of the popularity list. Double Wide TVs might be a little overkill!
3D – What Happened?
The long and the short of it is that it just wasn’t that popular. They’re still available to buy – the nature of modern tech means few things ever really get to die, but they’re high maintenance, for a TV. They take special effort to make work. They suffer from all the same qualities as a regular LCD screen, but now with the added disadvantage of the 3D setting – yeah, you can use it on regular movies, but if the media wasn’t made with 3D in mind, it’s not going to look as nice as something made specifically for 3D.
Which you often had to go out of your way to find even when 3D movies were all the rage, because it just wasn’t that easy to get a 3D effect on home markets. Why make a second edition of a disk for only the people who had 3D screens, right? It’s why Apple wasn’t fully color-customizable up until recently, if a color doesn’t sell, they’re stuck with the stock.
3D screens are still available – but you probably shouldn’t buy one if you’re not really into it.
Sources:
https://www.youtube.com/watch?reload=9&v=v5OANXk-6-w
https://computer.howstuffworks.com/monitor7.htm
https://electronics.howstuffworks.com/3d-tv.htm