Steve Jobs did a great job at Apple, but he also changed the world. A simple 7-segment display is not enough for even the most simple of applications today; customers are asking for bigger displays with more impressive graphics. Marketing teams are therefore asking engineering teams to implement this on the next generation of products. This is true for many applications, such as coffee machines, ovens, factory automation and household boilers, and is naturally presenting a new and interesting challenge for engineering teams. So the simple question is how to add a display into your application?

Let us first have a look at what different options you have in picking a display. There are lots of TLA’s (three letter acronyms) used in the industry which are actually very simple but can lead to a bit of confusion.

Everyone in the engineering community is familiar with the Liquid Crystal Display (LCD) concept; even if they have subsequently moved to the dark side and are now working in “sales” they will likely remember the calculator that they once had to use for real work, that had an LCD screen on it.

The basic concept is very simple. A layer of liquid crystals is arranged between two polarized layers (at 90 degrees to each other), such that without the liquid crystal, no light would pass through at all, but the crystal is arranged in a kind of helix pattern which rotates the polarization of the light between the two polarized screens, meaning all the light can pass though. However, when an electric charge is applied to the liquid crystals they unroll or straighten out, thus no longer rotating the light and will appear black.