When the idea to write about some of the display technologies found in smart phones today clicked me I thought it will be easy to dig them out before I put a word to it but I guess watching a picture on my smart phone is fairly simple than to know how this is rendered to look sharp and vivid onscreen.
Finally I got something into my head, here I go watch yourself.
Two technologies that are going and evolving side by side at the moment are LCD and OLED. I am sure you have heard of them already but my purpose is to dig them bit deeper.
Liquid Crystal Display or commonly known as LCD is a display technology that is found not only smart phones but also in TVs, signage, watches, calculators, computer monitors, video players, gaming devices and so on.
Since I am not going to be heavily technical about explaining these smart phone display technologies LCD due to a number of reasons such as being light and energy efficient, the ability to be made in any size, little or no flickering depending upon backlight tech, and zero chances for image burn-in has replaced CRT display technology. There are two scheme of pixels used in LCD: Passive Matrix, and Active Matrix.
Passive Matrix LCD was a standard in 80s until in mid 90s when Active Matrix led the market because of its sharper content displaying ability, low cost, and low power consumption. Many advance TVs, smart phones, and laptops until today rely on Active Matrix LCD tech. One bad thing in it is that under direct sunlight the onscreen information cannot be view properly.
An advancement in LCD is IPS LCD (In-Plane Switching LCD) that Apple is using its iPhone 4, iPad (calls it Retina), and Motorola Droid also has same display technology. In all of them Active Matrix scheme is used, in fact I have found no smart phone manufacturer using Passive Matrix.
A little better than LCD is Organic Light Emitting Diode (OLED). It has a number of advantages over LCD including the ability to display deep black levels of colors and producing high contrasting colors under ambient light, the ability to be lighter and thinner, its faster response time, wider viewing angles, wider and stable color gamut, all makes OLED better than LCD.
OLED is widely used is smart phones, portable devices, TVs, computer monitors etc.
Passive and Active Matrix arrangements also exist here and as in LCD tech Passive Matrix is not a commercial hit with OLED.
Active Matrix Organic Light Emitting Diode, aka AMOLED, consists of an active matrix of OLED pixels that generate light upon electrical activation that have been deposited or integrated onto a thin film transistor (TFT) array, which functions as a series of switches to control the current flowing to each individual pixel.
AMOLED is currently used by Samsung in Galaxy SII with a variant name of Super AMOLED Plus. This tech has high value of color contrast and brightness.
The Super AMOLED Plus screens have 1,152,000 subpixels, a 50 percent increase over the 768,000 subpixels in the Super AMOLED display. You must have seen the eye popping display of Galaxy SII, it is due to this display tech.
Apple’s Retina is a direct rival to Samsung’s Super AMOLED Plus. Retina has a greater advantage of pixel density and resolution where Super AMOLED Plus scores best at screen brightness and color contrast.