An Introduction to Thin-Film LCDs
Liquid-crystal displays (LCD) are used in countless consumer and commercial display applications. Even if you're unfamiliar with their mechanics, you've probably used an LCD before. Computer monitors, smartphones, smart appliances, point-of-sale (POS) systems and human machine interfaces (HMIs) all use LCDs. There are many different types of LCDs, however, one of which is thin film. What is a thin-film LCD exactly?
The Basics of Thin-Film LCDs
A thin-film LCD is a special type of LCD that lives up to its namesake by using thin-film transistors. Like all LCDs, it features liquid pixels, which are usually made of an organic material. Thin-film LCDs also have backlighting, such as light-emitting diode (LED) bulbs, that illuminates the pixels from behind. Only thin-film LCDs, however, have a thin-film transistors. This is essentially what distinguishes them from other types of LCDs on the market.
With thin-film transistors, each pixel has its own transistor. This is in stark contrast to other types of LCDs that allocate transistors for groups of multiple pixels.
Most LCDs use transistors made of crystalline silicon. Thin-film LCDs, however, use transistors made amorphous silicon, allowing for a smaller profile. When compared to crystalline silicon transistors, these amorphous silicon transistors - also known as thin-film transistors - take up just a fraction of the space. As a result, manufacturers can use more transistors in the construction of thin-film LCDs.
Some of the different types of thin-film LCDs include the following:
- Twisted nematic (TN)
- In-plane switching (IPS)
- Multi-domain vertical alignment (MVA)
- Patterned vertical alignment (PVA)
- Advanced super view (ASV)
- Advanced fringe fringe field switching (AFFS)
- Plane line switching (PLS)
