There is only limited number of frames/s in TV transmission. Many stations like FOX or ABC broadcast everything in 60fps 720p. When 24fps movie is broadcasted they just repeat frames. Digital TV set adds (interpolates) additional frames, so if you set it to 240Hz it will add 3 interpolated frames to each "real" frame. It would be even better if TV would send movies in original 24fps because TV would be able to interpolate, especially at 120Hz that is even multiple of 24fps.
I don't thing that images are "drawn" anymore. Each pixel on the screen of LCD TV has corresponding bit in frame memory buffer and whole frame appears at once. Frames itself are very sharp even with 24fps because shutters in film cameras are very fast. The problem is transition between frames that appear to be jittery with fast motion. If you smooth it up too much, tossing in too many interpolated frames, you'll get "soap opera effect". I'm still trying to find optimal setting for movies on my TV - not too fast and not too slow.
I don't thing that images are "drawn" anymore. Each pixel on the screen of LCD TV has corresponding bit in frame memory buffer and whole frame appears at once. Frames itself are very sharp even with 24fps because shutters in film cameras are very fast. The problem is transition between frames that appear to be jittery with fast motion. If you smooth it up too much, tossing in too many interpolated frames, you'll get "soap opera effect". I'm still trying to find optimal setting for movies on my TV - not too fast and not too slow.