What is lcd?
An LCD, or Liquid Crystal Display, is a flat screen technology that uses liquid crystals to control light and create images. It works by sandwiching a layer of liquid crystals between two pieces of glass, then using electricity to change how the crystals align, which either blocks or lets light pass through to form pictures.
Let's break it down
- Backlight: A bright LED panel behind the screen shines light forward.
- Polarizers: Two filters on the front and back of the liquid crystal layer let only light vibrating in certain directions pass.
- Liquid crystals: Tiny molecules that can twist when voltage is applied, changing the light’s direction.
- Color filters: Tiny red, green, and blue sub‑pixels that combine to make all colors.
- Control circuitry: Tiny transistors (TFTs) switch each pixel on or off based on the image data.
Why does it matter?
LCDs are cheap, thin, and use very little power compared to older CRT screens. This makes them ideal for smartphones, laptops, TVs, and many other devices where size, weight, and battery life matter.
Where is it used?
- Smartphones and tablets
- Laptop and desktop monitors
- Television screens
- Digital watches and calculators
- Car dashboards and instrument panels
- Public information displays (e.g., airport boards)
Good things about it
- Low power consumption, especially with LED backlights
- Thin and lightweight, allowing sleek device designs
- Good color reproduction and sharp images for most everyday uses
- No screen burn‑in like some older technologies (e.g., plasma)
- Relatively inexpensive to manufacture at scale
Not-so-good things
- Limited viewing angles; colors can shift when you look from the side (though IPS panels improve this)
- Slower response time than some newer tech like OLED, which can cause motion blur in fast action scenes
- Black levels aren’t as deep because the backlight is always on, leading to less contrast in dark scenes
- Can suffer from “ghosting” or “image persistence” if static images stay on too long.