How does an LED television screen emit light? My understanding is that the screen consists of many pixels, and each pixel has red, green, and blue LEDs. An electrical current runs through every red, blue, and green LED to determine each pixel color.

How does the electrical current determine each pixel color? Every pixel in a frame can have a different color, so how does an electrical current give pixels different colors in the same frame?

  • 3
    $\begingroup$ Do you know how additive mixing of color works? $\endgroup$ Nov 4, 2020 at 2:20

1 Answer 1


The red, green and blue LEDs are not connected in series. The current of each LED is controlled independently, and determines how much light that LED emits. For instance, for a yellow pixel, a large current flows through red and green LEDs while a low (or no) current flows through the blue LED. The mixture of red and green light is perceived as the color yellow.

  • $\begingroup$ Good answer! How are different currents distributed to different pixels to create a single frame? Which part of the TV is responsible for distributing different currents to different pixels to create a single frame? $\endgroup$
    – ktm5124
    Nov 4, 2020 at 2:58
  • $\begingroup$ @ktm5124 Unfortunately I don't know too much about the display control circuit and where it is located. It might be a dedicated chip or embedded in another controller chip. A digital-to-analog converter (plus some calibration arithmetic) converts the digital RGB values to analog values, which are then applied as currents to LEDs. $\endgroup$
    – Puk
    Nov 4, 2020 at 3:14
  • $\begingroup$ @Puk - I would think pulse width modulation rather than analog control for brightness control. $\endgroup$
    – Jon Custer
    Nov 4, 2020 at 17:43
  • $\begingroup$ @JonCuster That makes sense actually, I really don't know much about display control circuits. I would be interested in an answer that includes the details if you know more. $\endgroup$
    – Puk
    Nov 4, 2020 at 17:46

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