As opposite to transmissive LCD, reflective LCDs can be viewed without any internal light source, if there is enough ambient light available. This means the power consumption is greatly reduced as compared to transmissive LCD, which requires an always-ON highly powerful backlight unit to compensate for the low light transmittance of a high pixel density LCD. However, for the reflective LCD to be used in dark ambience, a frontlight unit is needed.

A clear advantage of an LCD over EPD is the high framerate and wide color gamut. However, there is a fundamental difference between the LCD and EPD in their optical reflection behaviors, which for the EPD is paper like (diffuse), and for the LCD a mix of mirror- and diffuse-like reflections. This sets specific, tough requirement for the illumination angle of a reflective LCD; it does not make sense to illuminate an LCD with light whose reflection pattern falls off the available viewing angles of the display.

This is where our technology comes into the picture. Nanocomp’s microstructures allow for steep enough illumination angle for the display, ensuring that the light reflected off the display will emerge within the useful viewing cone of the display. The peak angle can be further adjusted to support the specific optical characteristics of the display, such as luminance and contrast ratio related qualities, as well as the intended viewing directions. Here, it should be noted that the optical bonding method of the microstructure surface to other layers of the display stack will affect the achievable light extraction angles.

The above mentioned two reflective display technologies are clearly the mainstream, but there are many other variations and implementations out there which deserve to be watched. Overall, there is a favorable trend in reflective display technologies due to their low power and reputation as eye-friendly products. The main applications lie in digital readers, wearables, tablets of all kinds, digital signage, and even smart phones.