IPS TFT (In-Plane Switching) and TN TFT (Twisted Nematic) are both types of TFT LCDs (Thin-Film Transistor Liquid Crystal Displays). The key difference between IPS TFT and TN TFT lies in the arrangement of liquid crystal molecules, which results in different display characteristics.
1. What is TFT? What is TFT LCD?
TFT stands for Thin-Film Transistor Technology. It is a special type of field-effect transistor (FET) made through a thin-film deposition process. TFT LCD refers to a liquid crystal display that employs thin-film transistor technology to enhance image quality.
In simple liquid crystal displays, the image elements are driven directly, allowing easy voltage application to specific segments of the display to generate images. However, this approach is impractical for larger displays, which consist of numerous pixels. To display colors, each pixel must be further divided into three primary color sub-pixels: red, green, and blue (R, G, B). All pixels, including the primary color sub-pixels, require connections at the top and bottom. TFT LCDs address this by connecting a thin-film transistor to each pixel, enabling precise control over each pixel, which is why they are referred to as active matrix LCDs.
2. What is TN? What is TN LCD? What is TN TFT LCD?
Before understanding TN TFT LCD, it’s important to know what TN (Twisted nematode) means.
TN refers to the twisted nematic effect, which is based on the controlled rearrangement of liquid crystal molecules between different ordered molecular structures under the influence of an electric field.
TN LCD (Twisted Nematic Liquid Crystal Display) is a type of liquid crystal display that utilizes the twisted nematic effect. It is one of the oldest and most cost-effective LCD technologies. Although most manufacturers have moved away from producing TN LCDs, they are still used in certain monochrome character displays.
TN TFT LCD is a TN LCD that incorporates thin-film transistor technology to enhance image quality.
3. What is IPS? What is IPS TFT LCD?
IPS (In-Plane Switching) is a liquid crystal display technology developed by Hitachi in 1996. In an IPS display, a layer of liquid crystals is sandwiched between two glass surfaces. The liquid crystal molecules are arranged parallel to these surfaces in a predetermined direction (in-plane). When an electric field is applied, the molecules reorient while remaining parallel to the surface, producing an image.
IPS TFT LCD is a type of thin-film transistor liquid crystal display that uses IPS technology to achieve superior image quality.
4. Differences Between TN TFT LCD and TFT LCD
TN TFT LCD is a specific type of TFT LCD. TFT LCD is a general term for liquid crystal displays that use thin-film transistor technology. TN LCD, being the oldest LCD technology, is often the first type of LCD that comes to mind when people think of LCDs. This has led to a habit of referring to TN TFT LCDs simply as “TFT LCDs,” which is incorrect since TFT LCD encompasses a broader range of technologies.
5. Differences Between IPS TFT and TN TFT
IPS TFT and TN TFT are both types of TFT LCDs. The main difference between them is the arrangement of liquid crystal molecules, which affects the display’s performance.
IPS TFT LCD: Utilizes a parallel alignment of liquid crystals relative to the panel surface, resulting in exceptional viewing angles, high color accuracy, and minimal color shift, even when viewed off-axis. This technology is synonymous with premium displays where image fidelity is non-negotiable.
TN TFT LCD: When TN TFT LCD is off, the twisted structure (also known as a helical or spiral structure) of the nematic liquid crystal molecules forms between the two glass plates. When the display is on, an electric field is applied between the electrodes, causing the liquid crystal molecules to align perpendicular to the panel surface. This perpendicular alignment is the main reason for the poor viewing angles in TN TFT LCDs.
6. IPS TFT vs TN TFT
IPS TFT technology is widely recognized as the pinnacle of LCD innovation, particularly suited for environments where display quality is critical. These include professional-grade monitors, color-critical applications, and high-end consumer devices.
Advantages: Unmatched viewing angles, high color gamut
Disadvantages: Slightly reduced response times and higher energy consumption
Conversely, TN TFT remains a mainstay in embedded applications due to its rapid response times and lower manufacturing costs. This technology is commonly employed in industrial displays, entry-level monitors, and portable devices where high-speed performance is prioritized over visual accuracy.
Advantages: Extremely fast response times, reduced motion blur, energy efficiency
Disadvantages: Limited viewing angles, inferior color accuracy, low color gamut
