Pixel pitch refers to the size of the gap between pixels in a display. In LCD, OLED and plasma displays, such as we find in televisions and smartphones, a different terminology is used to express a similar concept. PPI (points per inch) or DPI (dots per inch), are measures that tell us the concentration of pixels in a given area. This is instead of expressing the distance between pixels. For example, a smartphone may have a very high DPI count, sometimes above 300DPI.
However, in the world of large scale digital signage and SMD LED Displays, such resolutions are neither possible nor necessary. Therefore, we talk in terms of pixel pitch instead. Older LED Displays, for example for use at large outdoor events, often have pixel pitches of 20mm or more, meaning there would be 2cm between pixels. On a large screen where the audience is a good distance away, this would be adequate to display video, text and images.
A 20mm pixel pitch would be completely useless on a device we view up close, such as a smartphone. For this reason, the intended viewing distance of the audience is very important when considering what pixel pitch is right for you. Image quality is also a factor; a lower pixel pitch display will look better at more viewing distances.
Modern LED Displays can have pixel pitches measured below a millimetre, producing very fine detail images, even at relatively close ranges. Another consideration is price – as pixel pitches get smaller, the displays get more expensive. The price rise is due to the increased costs of greater manufacturing precision and smaller components. For more information on the relationship between pixel pitch and viewing distance, please view the ‘What pixel pitch do I need for my viewing distance?’ section below.