Thursday, January 18, 2018

Cellphone Displays

You may think that all cellphone screens are the same, but that couldn't be further from the truth. Cellphone screens can vary greatly from phone to phone, and the type of screen that your phone has makes a big impact on how you use the device. Here's an overview of the most common types of screens found on cellphones.
Image result for cell phone display
LCDs 
A liquid crystal display (LCD) is a thin-panel display that's used in many computers, TVs, and cellphones, but there actually several different types of LCDs.
Here are the types of LCDs you're likely to find on a cellphone.
  • LCD – An LCD requires a backlight, which means that an LCD display requires more power than other types of displays. This could be taxing on your phone’s battery. LCDs are thin and light, though, and inexpensive to produce.
  • Thin-Film-Transistor (TFT) – TFT-LCD displays are an improvement to the quality of older LCD displays. The display delivers sharp images but offers poor viewing from an angle. This display is best viewed from straight on. 
  • In-Plane Switching (IPS) – IPS-LCDs are an improvement over TFT-LCDs in that they offer better color reproduction and wider viewing angles. They are used on midrange and high-end smartphones and portable devices. 
OLED Displays
Organic light-emitting diode (OLED) displays are able to deliver sharper and brighter images than LCDs, while using less power. Like LCDs, OLED displays come in a variety of types.
Here are the types of OLED displays you're likely to find on smartphones.
  • OLED Display – An OLED display doesn't require a backlight to light the display pixels. It uses organic hydrocarbon chains that emit light. Each pixel makes its own light. The contrast is high, which allows for dark blacks and bright whites. The lifetime of the display may be shorter than that of an LCD due to the organic nature of its components.
  • Active-Matrix OLED (AMOLED) – AMOLED displays pair part of a TFT display with an OLED display for quick response times and power savings. 
  • Super AMOLED Display – Super AMOLED builds on AMOLED technology. It delivers a 20 percent brighter screen and uses 20 percent less power. Because it has substantially lower sunlight reflection than an AMOLED display, it is ideal for phones that are frequently used outdoors.
Touch Screens
A touch screen is a visual display that acts as an input device by responding to the touch of a user's fingers, hand, or an input device such as a stylus. Not all touch screens are the same. Here are the types of touch screens you're likely to find on cellphones.
  • Touch Screen – The first touch screens were resistive. They weren't sensitive to the touch of a human finger. They were sensitive to a stylus that applied pressure to the screen.
  • Capacitive Touch Screen – This display uses the conductive touch of a human finger or a specialized device for input. 
  • Multi-Touch Screen – A multi-touch screen can detect input from two or more points of contact at the same time.
Retina Display
Apple calls the display on its iPhone a Retina Display, saying it offers more pixels than the human eye can see.
It is difficult to pin down the exact specifications of a Retina display because the iPhone has changed size several times since the technology was introduced. However, a Retina Display delivers at least 326 pixels per inch.
With the release of the iPhone X, Apple introduced the Super Retina display, which has a resolution of 458 ppi, requires less power, and works better outdoors. Both Retina and Super Retina displays are only available on Apple iPhones.