LCD – Liquid Crystal Displays

Liquid crystals were first discovered in the late 19th century by the Austrian botanist, Friedrich Reinitzer, and the term liquid crystal itself was coined shortly afterwards by German physicist, Otto Lehmann.

Liquid crystals are almost transparent substances, exhibiting the properties of both solid and liquid matter. Light passing through liquid crystals follows the alignment of the molecules that make them up – a property of solid matter. In the 1960s it was discovered that charging liquid crystals with electricity changed their molecular alignment, and consequently the way light passed through them; a property of liquids.

Since its advent in 1971 as a display medium, liquid crystal displays have moved into a variety of fields, including miniature televisions, digital still and video cameras and monitors and today many believe that the LCD is the most likely technology to replace the CRT monitor. The technology involved has been developed considerably since its inception, to the point where today’s products no longer resemble the clumsy, monochrome devices of old. It has a head start over other flat screen technologies and an apparently unassailable position in notebook and handheld PCs where it is available in two forms:

  • low-cost, dual-scan twisted nematic (DSTN)
  • high image quality thin film transistor (TFT).

Twisted nematic (TN) LCD remains the technology of choice for many low to mid range monitors and notebook screens, and after considerable development is also utilised in many flat panel televisions. Early Super Twisted Nematic (STN) LCD technology gave a low cost but effective monochromatic display commonly used in mobile phones and PDAs even well into the 2000s. However, since around 2006 or so almost all LCD screens, and we’ll see that whatever their size or purpose, whether TN or TFT, they are full colour, bright, fit for purpose and backed with an extraordinary level of technology.