Got a new 1080p LCD TV recently so that I can now watch the Ravens suck in HD in two rooms of the house 
It is a 47" LG. Why is it 2" thick while my laptop screen is only 1/2" thick? If it is to enclose the associated electronics, why not put those in a standalone box with a cable to a nice super thin display?
The only thing I can think of is that a 1/2" thick 47" assembly would flex and break so the depth is beefed up a bit to prevent this.
The main reason is that it is more expensive to make the screen really thin. In the case of TVs 2 inches is thin enough but in a laptop 2 inches is unacceptable.
Hmmm…so if I was to take a screwdriver to my new telly, how thick would the actual LCD panel be? 2"?
I think flexing and back lighting are important factors. Laptops used to use very small florescent tubes IIRC, I think its moved to LED’s now. it seems like both fairly expensive to upsize to 47in, larger light sources would appear to be cheaper and more even.
Lots of reasons. The electronics your laptop screen needs, like a power transformer, are located in the main part of the laptop rather than behind the screen. In a TV, those electronics are behind the panel. Large LCD panels need lots of backlighting to make them bright enough to compete with a well-lit room, so that’s behind the panel too. All of that backlighting generates a lot of heat, so there are generally fans behind the panel. Models with built-in speakers need to be thick enough to accommodate the speakers. You need space for all of the various connections (HDMI, component, s-video, etc.). There is a lot of stuff behind the panel in an LCD TV.
I understand that which is why, in my OP, I suggested all that stuff goes in a separate box. Yes the backlights would remain and maybe fans although none of my flat panels have fans. Nothing else.
How thick would it be?
I don’t have a measurement, but this link should give you an idea of how thin an LCD TV can be. Some models from Sharp have a new form factor. The edge of the TV is very thin, but there are a few bump-outs for electronics and the mount for the stand which keep the overall thickness at a few inches. If they took away all of the stuff in the bump-outs (and put it into your separate box), you’d have what is probably the thinnest LCD TV (of that size) that you could have.
Actually, if OLEDs work out, you should be able to get a VERY thin display. And they’re starting to appear over the commercial horizon:
Sony is selling a small one now:
http://www.pcworld.com/article/id,137884-c,tv/article.html
This guy thinks affordable big OLED screens are 5-6 years off: