The LCD display screen is composed of current stimulating liquid crystal molecules to generate dots, lines and faces to match the back lamp.
In a color LCD display, each pixel is divided into three cells, or sub-pixels, and the additional filters are labeled red, green, and blue. The three sub-pixels can be controlled independently, and the corresponding pixels produce thousands or even millions of colors.
The LCD can be either transmissive or reflective, depending on where the light source is placed. The transmissive LCD is illuminated by a light source behind the screen, while viewing is on the other side of the screen. This type of LCD is often used in applications that require high brightness, such as computer monitors, PDAs, and cell phones. Lighting devices used to illuminate LCDs tend to consume more power than the LCD itself.
Reflective LCDs, commonly found in electronic timepieces and computers, reflect the external light back from the backscattered reflective surface to illuminate the screen. This type of LCD has a high contrast ratio, because the light passes through the liquid crystal twice, so it is cut twice. The small reflective LCD consumes very little power and the photocell is enough to power it.
The transflective LCD can be used both as a transmissive type and as a reflective type. When the external light is sufficient, the LCD works as a reflection type, and when the external light is insufficient, it can be used as a transmissive type.