Unveiling Liquid Crystal Displays: How Does Your Screen "Light Up"?

In our previous discussion, we explored the birth and classification of liquid crystals. Today, let’s delve deeper: How exactly do liquid crystal displays work? How do the screens of your smartphones and computers use electricity and light to present vibrant and colorful images?

The "Heart" of an LCD: The Dance of Electric Fields and Light

The fundamental principle of liquid crystal displays can be summarized as: An electric field controls the alignment of liquid crystal molecules, which in turn controls the passage of light, ultimately forming an image.

Simply put, liquid crystals act as a "switch" for light:

• Without voltage applied: Liquid crystal molecules align regularly, twisting light by 90°, allowing it to pass through the polarizer. The screen appears "bright" (non-display state).
• With voltage applied: The alignment of liquid crystal molecules is disrupted, losing their light-twisting ability. Light is blocked by the polarizer, and the screen appears "dark" (display state).

By controlling the voltage in different areas, contrast between light and dark is created, forming text and images.

The "Extended Family" of LCDs and Their Technical Differences

Depending on the degree of molecular twist, LCDs can be categorized into various types, each with distinct performance characteristics and applications:

• TN (Twisted Nematic): Fast response time, low cost, suitable for simple display devices like calculators and watches.
• HTN (High-Twist Nematic): Wider driving range, slightly improved viewing angles, suitable for caller ID devices and educational tools.
• STN (Super-Twisted Nematic): Higher contrast, suitable for high-resolution displays like early mobile phones and GPS devices.
• VA (Vertical Alignment): Extremely high contrast, pure black representation, commonly used in high-end monitors.
• IPS (In-Plane Switching): True color reproduction, wide viewing angles, ideal for professional applications like design and video editing.
• TFT (Thin-Film Transistor): Each pixel is controlled by an independent transistor, offering fast response and excellent color performance. This is the mainstream technology for modern smartphones and computer screens.

In summary:

TN: Fast response, low cost, but limited color and viewing angles.

VA: High contrast, ideal for entertainment.

IPS: Accurate colors, wide viewing angles, suitable for professional use.

TFT: Strong overall performance, the preferred choice for modern smart devices.

How to Evaluate an LCD Screen? Four Key Performance Indicators Explained

When selecting an LCD screen, beyond size and resolution, pay attention to the following four core indicators:

• Contrast Ratio

The brightness ratio between the brightest and darkest areas. A higher contrast ratio results in clearer images with better depth. Generally, a ratio ≥1000:1 is recommended.

• Response Time

The speed at which pixels transition from bright to dark or vice versa, measured in milliseconds (ms). Shorter response times reduce motion blur, making them ideal for gaming and dynamic content.

• Viewing Angle

The consistency of color and brightness when viewing the screen from different angles. IPS screens typically offer wide viewing angles up to 178°.

• Color Performance

Includes color gamut coverage, color accuracy, and color depth. Professional design and video production require attention to sRGB, Adobe RGB, or DCI-P3 color gamut coverage.

CNK: Driving the Future of Displays with Technological Innovation

In today’s era of continuous evolution in liquid crystal technology, CNK leverages its profound technical expertise and specialized product portfolio to provide customers with comprehensive display solutions—from standard products to customized designs. We not only manufacture TFT display modules, OLED modules, and HMI human-machine interaction modules ranging from 0.96 to 15.6 inches but also possess extensive project experience in the field of monochrome LCDs and modules.

Adhering to a customer-oriented approach, our products strictly comply with international standards, ensuring they meet your expectations in performance, quality, and delivery.

CNK—focused on displays, specialized in customization—is committed to illuminating every creative vision with the technology of light and shadow.

About CNK
Founded in Shenzhen in 2010, CNK Electronics (CNK in brief) expanded the world leading factory in Longyan, Fujian in 2019. It is a national specialized and innovative "little giant" enterprise that specializes in the design, development, production and sales of display products. CNK provides customers with a full range of cost-effective small and medium-sized display modules, solutions, and services with excellent quality worldwide. Oriented in technology and high quality, CNK keeps sustainable development, works to offer customers  better and stable services.