The Evolution of Smartphone Displays
Display performance is increasing with each new smartphone generation.
17 Jul 2020
The use of large touch displays revolutionized mobile phone operation and use. Mobile phones became smartphones. Today, they dominate the market. With each new generation of smartphone, the technology used in the devices became more powerful. As a key functional component, displays have also developed tremendously. Today's smartphone displays offer outstanding performance in terms of resolution, size, picture quality and functions. The development possibilities appear to be far from exhausted.
In the classic mobile phones of the 1990s, the displays merely served to show information. They were small and monochrome and initially only intended to display phone numbers or call information. Gradually, other display functions were added. The displays became more colorful and larger. However, the telephone was still operated using normal keys. The market launch of Apple's iPhone in 2007 marked a fundamental switch from display screens to touch displays that could be operated using your finger. Although some manufacturers had previously offered smartphones with screens that could be operated with a pen or by hand, it was only with the iPhone and the iOS operating system that the finger operating concept became established. The classic keyboard had shrunk to a single key, the home button. This marked the beginning of the meteoric rise of the smartphone.
The following offers a brief overview of the development of smartphone displays from their beginnings to today.
The first generation of smartphone displays were between three and four inches in size. Their resolution was relatively low and pixels were clearly visible to the human eye. For example, the first generation of iPhones had a resolution of 480 x 320 pixels. The manufacturers increased the pixel densities relatively quickly. Within only a few years, they doubled, so that displays with HD and later with Full-HD resolutions appeared on the market from as early as 2010. Today, you can buy smartphones with 4K resolution and pixel densities of over 800 ppi. Parallel to the higher pixel densities, the display size also increased. Current models feature displays measuring from 5 to 6.5 inches or more. Particularly large smartphones are also known as phablets, a mixture of smartphone and tablet.
A great deal has also changed in terms of the display technology used. Early models used simple LC displays. In order to improve display characteristics such as contrast, brightness, color representation and viewing angle stability, LC displays with IPS technology (in-plane switching technology) became widely used by many manufacturers. Parallel to IPS displays, so-called OLED displays became more and more important. They have organic, self-illuminating, individually controlled LEDs and do not require background lighting as LCDs do. The advantages of these displays are high contrast values, good color saturation and low energy consumption. The two technologies IPS and OLED have become firmly established in the smartphone market.
The bigger the display, the bigger the smartphone. For this reason, the edges around the displays have become narrower. Some manufacturers meanwhile produce smartphones with completely frameless displays. This even goes so far that the displays show content or operating elements bent over the edge of the housing. To prevent mechanical damage to the sensitive displays, manufacturers use specially hardened, particularly tough glass.
Like the first generations of devices before them, today's smartphone touch displays are invariably so-called capacitive touch displays. They react to a gentle touch with the finger without the need to apply pressure. Smartphone manufacturers have further refined this operating technology and integrated additional functions into the displays. Smartphones are now available that provide haptic feedback when touched, differentiate between a gentle touch and firm pressure, or recognize the difference between knuckle and fingertip contact.
Smartphone display technology is far from reaching the end of its development. Smartphones are now available with foldable screens. Although these devices have not yet established themselves on the mass market, they make it possible to offer larger screens without having to increase the size of the devices themselves. Manufacturers are also working on developing displays with even higher resolutions, lower energy consumption and better display characteristics. Research is also being conducted on curved or completely flexible, roll-up displays.