1. Liquid-crystal display (LCD) and organic LED (OLED) display

An FPD is an assembly of minute dots called pixels. Various images are displayed by controlling the brightness of these pixels.

Liquid-crystal display (LCD) is a flat and thin display device that uses a liquid crystal composition, which is commonly known as liquid crystal. This liquid crystal has the properties of both a liquid and solid, and the liquid crystal itself does not emit light. It works as a shutter that controls the intensity of light that passes through each pixel.

Organic LED display (OLED display) is a display device utilizing light-emitting diodes (LEDs) that have a light-emitting layer made from organic compounds. An LED emits light when an electrical current flows through it. The intensity of light can be adjusted by changing the amount of electrical current.

In both LCD and OLED display, each pixel consists of red, green, and blue. For each color, a switch function called thin film transistor (TFT) is provided to control the intensity of passing light.

Structure diagram of liquid-crystal display and organic LED display. Images of both displays are composed of three colors (red, green, and blue), and a thin-film transistor (TFT) acts as a switch that allows light to pass through.