I had a (regrettable) 19" 4x3 ViewSonic display that made that problem obvious -- way back in 2008 or so.
My homework at that time revealed a couple of things:
1. Liquid crystals are individually driven by AC waveforms, not DC as one might assume. This is the nature of the beast. The frequency at which the signal alternates is not necessarily very high. Thus, sometimes, this alternating nature is visible.
2. Some displays use dithering. A given display might support just -- say -- 6 bits per subpixel. To get the full 8 or 10 or whatever number of bits that are expected as a final output, the in-between steps are approximated by switching between two values -- sometimes (again) at a fairly low frequency that is visible.
...
But anyway, that ViewSonic monitor: Most people thought it looked fine, but it drove me nuts.
My homework at that time revealed a couple of things:
1. Liquid crystals are individually driven by AC waveforms, not DC as one might assume. This is the nature of the beast. The frequency at which the signal alternates is not necessarily very high. Thus, sometimes, this alternating nature is visible.
2. Some displays use dithering. A given display might support just -- say -- 6 bits per subpixel. To get the full 8 or 10 or whatever number of bits that are expected as a final output, the in-between steps are approximated by switching between two values -- sometimes (again) at a fairly low frequency that is visible.
...
But anyway, that ViewSonic monitor: Most people thought it looked fine, but it drove me nuts.