I understand that for both LCD and OLED, different voltages are applied to get the diode to react differently and emit different colors and brightness levels. But how do they control each of these millions of pixels simultaneously? Are there literally millions of tiny copper wires going to each pixel?
In: Engineering
Not millions of actual tiny separate wires, but effectively the same thing. The backplane of the display (the part that provides power and control) has millions of tiny conductive paths *printed* on it by very complex machines. It’s basically the same technology used to make microchips, just scaled way up.
Modern LCD and OLED panels are what’s called “active matrix”, which means there is a wire for each row and each column, forming a matrix, and an active component at each crossover point joining the rows and columns.
The active component is a transistor, an electronic switch. The switch only turns on only if it receives a signal on both the row and column, so you can address M x N individual pixels with only M + N wires. The panel controller activates each combination of row and column in turn. How strong the signal is determines the final brightness of the (sub)pixel controlled by that transistor.
https://en.m.wikipedia.org/wiki/TFT_LCD#Construction
Yes but not as many as you think – they are run from a matrix so to light an LED at position A use wires X & Y, to light position B use wires X and Z and so on.
I’m not sure about home TV devices, but the really large wall sized LED screens have individual controllers for sections of the TV. One controller might control a 10 foot by 10 foot sections for example not the entire screen.
I would image that there might be even smaller individual controllers hidden inside the screen to subdivide the work so that you don’t have to run “wires” from each pixel to each controller. I do not know how they divide the work, but it seems like it would be more practical..
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