I found
First Principles of Television (History of Broadcasting: Radio to Television) at the used book store this weekend and I'm absolutely engrossed in it.
It's not at all what you'd think it'd be. It's basically a primer on the technological history of television, complete with circuit diagrams.
It was made before the CRT caught on (though in the book the author talks about some guy who devised a cathode ray tube system, which the author thinks is very ingenious but unfortunately impractical) so it's all about mechanical televisions, and he has some interesting footnotes directing towards working designs of HD color projection televisions, which I now feel that I must build.