Yup, they are flashing… It is really that simple… The rows and colums are “flashing” on and off in a kinda wave. Each Led is clicked on during each wave but it is quick enough that your eye can’t see it --or can’t see the “change”.
I actually had this same I actually had this same question. Lets say I wanted those 3 LEDs to stay lit for 5 seconds. How is it that that fourth LED wouldn’t be lit? If I lit up the rows and columns needed for the 3 LEDs the 4th would light because its row and column were both activated.
When the 4th column is on, When the 4th column is on, only light the 4th row, when the 5th column is on, only light the 4th and 5th rows. So cycling through each column at greater than say 15 columns per second, only turn on selected rows at the time a given column is on. This might be just enough for persistence of vision to register the specific LEDs on.
Yeah I got it now. I didn’t Yeah I got it now. I didn’t understand that he said they would be flashing at a high rate. As long as they flash 25-30 times a second the human eye won’t see the LED as blinking. Thats why most cameras film at 30 FPS. The human eye thinks the movement is continous even though it is flashing still pictures.