On Mon, May 20, 2024 at 12:06:13PM -0500, CAREY SCHUG via cctalk wrote: [...] > so, just curious. how do digital TVs (and monitors) work? I presume the > dots are a rectangle, not sloping down to the right, no half a line at the > top and bottom. Do they just assume the brain can't tell that (for the > converted old analog tv signal) the image therefor slopes UP very slightly > to the right from what it "should" be? and the top line is blank on the > left side because that is the interlace frame?
The half-lines are not visible on an analogue CRT (unless it's faulty or miscalibrated) because they're hidden behind the top and bottom of the screen bezel, assuming that they're even sent to the electron gun at all. A digital TV displaying an analogue signal will just crop the image to simulate the bezel, since there's a lot of other cruft and noise in the signal which is not actually picture data and would be quite distracting if you could actually see it. The slope in the scanlines is very gentle and pretty much not noticable unless you're looking for it, and maybe not even then. You may well look at it and say "yeah, that's on a slope", but is that due to the scanning process or because the deflection yoke is twisted slightly? There are so many adjustments on a CRT that affect each other that getting a picture at all is a minor miracle. I don't miss CRTs.
