This is all speculation, but I suspect the reason
Jeopardy! has been slow to implement one giant screen has been for the following reason. (And I hope that the UK/Australian version was able to avoid the problem.)
I'll be referring to
this YouTube video Wheel of Fortune posted about its new puzzle board.
Giant video displays are currently made by assembling individual squares of 3-color LED arrays into whatever shape is desired (as seen at 0:25).
Here's a representative picture of an individual square -- I understand that you can also get tiles in which the LEDs are grouped more tightly together. Just like a computer monitor, the more LEDs/pixels there are, the higher the resolution. (In reading the description of the LED panel I linked to, it appears that it isn't a one-to-one ratio. I don't know the specific technical details of LED screen resolution.)
LED panels look great from a distance -- the giant screen in the back of the
TPIR audience has been made up of this type of LED panel for well over a decade. However, if the camera zooms in too close, then you get a moiré effect where it appears that the screen is producing an uncontrollable, moving, fine-lined wave pattern. Every once in a great while, on the current
Let's Make a Deal, the camera will zoom in too close to an in-studio contestant seated directly in front of a screen displaying the at-home contestants, and you can see the beginning of the effect start to occur.
The best solution, then, is to never zoom too close to the giant LED screen. On shows that occasionally need to zoom in that close (for example, the screens behind the celebrities on
Nashville Squares were made of this type of LED panel), a large piece of translucent plastic can be placed over the LED panels. This diffuses the light and prevents moiré, but the tradeoff is that you lose crisp, sharp edges in the graphics. It's clear that that's what
Wheel of Fortune has done because the show anticipated taking close-ups of Vanna at the board and/or because they needed a flat surface for touchscreen purposes. Even with the plastic overlay, things start to get pixel-y if you zoom in too close (as can be seen at 0:30).
Again, this isn't an issue if you intend to display large pictures or giant letters. However, the primary function of the
Jeopardy! board is to display five rows of clues, each in a relatively small type size. If the LED technology is too primitive, then the text would appear either jagged along the edges (if the LED resolution is too low) or blurry (if a plastic overlay diffuses the light too much). And that would be a big problem when the contestants need to easily read the text in order to play the game.
If the UK/Australian version has gone with one giant LED screen, then I hope that means the technology has caught up to the point where those are no longer problems. The letters of the little
Wheel of Fortune logos on the current puzzle board are roughly the height of one line of
Jeopardy! clue text, and those look adequate. Some of the thinner lines aren't reading quite right, but that may be a result of a low-quality logo graphic rather than the fault of the LEDs. But I assume that's why
Jeopardy! hasn't installed one giant LED screen up to this point.
