We originally created the article: Why Do Some OLEDs Have Motion Blur?
There is a high-speed video of a Sony Trimaster OLED display which shows the same OLED scanning method written in a paper by japanese scientists (Figure 20).
OLED still uses top-to-bottom scanning that both LCD (video) and CRT (video) still do today.
EDIT: There is a new 2019 High Speed Video of OLED
Image Credit: Figure 20 in OLED paper on Journal of Vision