Whitepaper: Energy Efficient Display Technologies

Energy efficiency is playing a more and more important role in our world. Many devices use a display to communicate with the operator. The display will consume a portion of the available electrical power, so it might be a motivation to investigate how to minimize it.

Although battery technology has developed to such an extent that devices can last a whole working day without recharging, the energy requirement for the backlight of a display is so high that it quickly becomes the largest consumer, especially when used outdoors in sunlight. Therefore, it makes sense to think about technologies that minimise this requirement. The translation of the colloquial term "readability" is the technical term "contrast". The higher the contrast, the easier the display can be read. This means that the displayed content is clearly distinguishable from the background. One way of achieving this is to minimise reflections from the display using special surfaces such as anti-reflective coating or the overall structure using optical bonding. Another way is to use a high brightness backlight. Unfortunately, as the brightness of the environment increases, the light energy that reaches the retina of the human eye decreases. In increasing ambient brightness, the iris reduces the opening through which light enters. 

This paper is limited to the consideration of electronic displays of the three common technologies LCD, OLED and e-paper. Bistable mechanical and exotic display technologies are not considered.