LCD(Liquid Crystal Display)

LCD (Liquid Crystal Display) is a photoelectric technology display device that uses liquid crystal materials, and is widely used in various electronic devices such as TVs, computer monitors, smartphones, and tablets.

Basic working principle

LCD displays work in the following ways:

The liquid crystal material is located between two transparent electrodes

Applying a voltage changes the arrangement of liquid crystal molecules

Liquid crystal molecules control the amount of backlight or ambient light that passes

Combine color filters to produce color images

Main types

1. TN (Twisted Nematic) LCD

The most traditional and lowest-cost type

The response time is fast, but the viewing angle is narrow

The color performance is average

2. IPS (In-Plane Switching) LCD

Provides a wider viewing angle (up to 178 degrees)

Color reproduction is more accurate

It is commonly used in high-end monitors and smartphones

3. VA (Vertical Alignment) liquid crystal

The contrast ratio is high, and the blacks perform well

The viewing angle is between TN and IPS

It is often used in TV products

Main components

Backlight system: Provide light source (CCFL or LED)

Polarizer: Controls the direction of polarization of light

Liquid crystal layer: Adjusts the amount of light passing through

Color Filter: Produces RGB primary colors

Drive circuit: Controls the voltage of each pixel 

Merit

Thin and lightweight

Lower power consumption (compared to CRT)

Flicker-free

No radiation

High resolution

Shortcoming

Limited viewing angles (especially TN panels)

Response time can cause motion blur

Blacks don't perform as well as OLED

Backlighting is required, which affects the contrast

Fields of application

TV and home theater systems

Computer monitors

Smartphones and tablets

Automotive dashboards and navigation systems

Industrial controls and medical equipment

Digital signage and billboards

With the advancement of technology, LCD technology is still evolving, and improved technologies such as quantum dot LCD and Mini-LED backlight have emerged to further improve display performance.