Advantages of IPS TFT LCDs
IPS is a TFT technology, sometimes referred to as a ‘super TFT.’
TFTs function by controlling brightness in red, green, and blue (RGB) sub-pixels (picture units). The pixels themselves do not produce light; instead, the screen uses a backlight for illumination.
The brightness of the LED backlights is adjustable. You can modify it to be brighter for sunlight readability, and dimmer for nighttime usage (such as a plane’s cockpit).
All TFTs are what is called active matrix displays.
An active matrix refreshes individual pixels rather than entire rows. The pixel is either on or off, but it does not fade while waiting for the next cycle.
This is accomplished by adding transistors and capacitors to each pixel. The additional components increase piece price but provides a sharper contrast and wider choice of colors. It is possible that pixels may fail, but this is rare.
The two most common types of TFTs are TN (twisted nematic) and IPS (in plane switching). The TFT type refers to the type of liquid crystal used in the display.
TN is the original TFT type that has been around for ages. It has remained the most popular type of TFT until recent years as more improved technologies are becoming more popular and less expensive.
TN, while the least expensive, is slowly being phased out due to poor viewing angles, contrast and color saturation. TN displays also have a narrow color gamut, which keeps them from displaying full 24 bit colors.
It isn’t all bad with TN TFTs though. They do offer the faster refresh rates than most technologies. However, the fast refresh rates aren’t usually required unless the display is being used for streaming video.
A-Si TFTs, also known as amorphous silicon LCDs, are also a TN type display.
IPS TFT’S (AKA SUPER-TFT’S)
IPS (In-Plane Switching) displays, also called super TFT’s, produce a wider viewing angle than TN TFTs.
The crystals in TN TFT’s run perpendicular to one another, whereas the crystals in an IPS TFT are parallel and remain parallel whether each pixel is powered on or off. This configuration produces a sharper, brighter and clearer image.
Advantages of IPS:
- Higher contrast
- True black background when the display or pixel is off.
- Wider viewing angle
- An estimated 85 degree viewing angle compared to 65 degrees of a passive display. Non IPS displays require the user to be directly in front of the display. Clarity is lost as the user moves up, down, left, or right of the center point.
- Wider color gamut
- TFT’s with IPS technology are more expensive than a-Si TFTs.
Viewing angle comparison between TFT (TN) and IPS
Which Type of TFT is Best?
If price is not as much of a factor and your product needs the wider viewing angle, sharper contrast, and additional colors, then choose IPS.
If viewing angle, color reproduction and contrast are less important than costs, or you need an extremely fast refresh rate, a TN TFT is probably the best choice.