Nokia reveals secret about their ClearBlack displays.

LCD displays have always had problems in displaying content under direct sunlight. Smartphones these days may have brilliant displays with the ability to display brilliant colours indoors, but, more often than not they falter under direct sunlight. One possible solution would be to boost the brightness levels up, but doing so takes a lot out of your battery and given how phones have massive, high-resolution displays, you certainly don’t want that. Like Super AMOLED, Nokia’s ClearBlack display is the only other display capable of delivering rich black levels and accurate colours, but it does so even under direct sunlight.

The Finnish company has now revealed what goes into making these displays work. It consists of three different polarizing layers, so once the light hits it, it’s processed many times over and only the light from the display is emitted, while light from external sources, like say sunlight is blocked. There’s a linear polarizer and retardation layer between the surface of the phone and the display. If you look at the image above, the light first hits the linear polarizer, which vertically polarizes the light. It then hits the second retardation layer, which makes the light right-circularly polarized. It then hits the screen switching it to left-polarization and begins its journey back. Passing through the retardation layer, it once again gets horizontally polarized. It then hits the first layer, which is the linear polarizer, but since the reflected light is now horizontally polarized, it’s blocked completely, thus completing the illusion. The light that’s emitted from your phone comes through just fine, because it only goes through the second half of the process. This is how the E7, Lumia 800 and 900 are able to achieve such good black levels even in direct sunlight.