Black-White-Time (BWT) is a measurement method for determining the response time of LCD and TFT displays
. The BWT time span
is the time that elapses when a dark pixel is activated, lights up brightly and falls back into the dark state. In other words, it goes through a black-white-black cycle. It is the sum of the rise time it takes for the pixel to change from the dark to the light state, and the fall time
when the drive voltage is turned off and the state changes from light to dark. These two times are not identical, because the pixel is still luminous when it is switched off. If the values for the reaction time are given, then therise
time is given first and then the fall time.