What method takes advantage of the polarization of light, with liquid crystals lined up between glass plates called pixels to manipulate light into making pixels light or dark?

What method takes advantage of the polarization of light, with liquid crystals lined up between glass plates called pixels to manipulate light into making pixels light or dark?

• A. Ultraviolet display
• B. Plasma display
• C. OLED
• D. Liquid crystal display (LCD)

Answer: (D)

The method relies on controlling light by changing its polarization with liquid crystals between two glass plates that form individual pixels. In an LCD, light from a backlight first passes through a polarizer, giving it a specific polarization. The liquid crystal layer, sandwiched between glass plates that hold tiny electrodes, can reorient the molecules when an electric field is applied. In a typical twisted-nematic arrangement, the crystals twist the light’s polarization as it travels through. The second polarizer (analyzer) is oriented perpendicular to the first, so when the crystals twist the polarization, the light passes and the pixel looks light; when a voltage aligns the crystals and reduces the twist, the light’s polarization is blocked by the second polarizer, making the pixel dark. Since LCDs don’t emit light on their own, a backlight provides illumination. Each pixel is controlled by its own electrode, enabling the on/off (light/dark) states across the display.

The method relies on controlling light by changing its polarization with liquid crystals between two glass plates that form individual pixels. In an LCD, light from a backlight first passes through a polarizer, giving it a specific polarization. The liquid crystal layer, sandwiched between glass plates that hold tiny electrodes, can reorient the molecules when an electric field is applied. In a typical twisted-nematic arrangement, the crystals twist the light’s polarization as it travels through. The second polarizer (analyzer) is oriented perpendicular to the first, so when the crystals twist the polarization, the light passes and the pixel looks light; when a voltage aligns the crystals and reduces the twist, the light’s polarization is blocked by the second polarizer, making the pixel dark. Since LCDs don’t emit light on their own, a backlight provides illumination. Each pixel is controlled by its own electrode, enabling the on/off (light/dark) states across the display.