How an LED TV Works

Most modern TVs combine LED and LCD technology. An LED TV is essentially an LCD panel illuminated by LED lights. The core concept behind image production is polarization.

Polarization refers to the direction of light wave oscillation. Unpolarized light oscillates in all directions. LED TVs use two polarization filters placed perpendicularly to control light. Initially, no light passes through both filters, but liquid crystals change that.

Liquid crystal displays (LCDs) utilize complex molecules that are naturally twisted. When light hits these crystals, their twist changes the light's polarization, allowing it to pass through the second filter. The degree of this twist, and thus the light intensity, can be controlled by an electric field applied to the liquid crystals.

TV screens are made of pixels, each containing three subpixels: red, green, and blue. Color filters are placed over these subpixels. By varying the intensity of light emitted by each subpixel (controlled by its own electrode), a wide range of colors can be produced. The human eye blends these subpixel colors to perceive new colors, with up to 16.7 million colors possible through 256 levels of brightness for each subpixel.