What Is A Smartphone - TechTarget

Smartphone displays

Smartphones commonly use liquid crystal display (LCD) screens in their displays. However, organic light-emitting diode (OLED) displays are becoming more common and preferred by manufacturers.

An LCD is a flat panel display that uses liquid crystals as its primary form of control. LCDs are lit with a backlight as pixels are switched on and off electronically while using the liquid crystals to rotate polarized light. Polarizing glass filters are placed in front and behind the pixels, and the front filter is situated at 90 degrees.

Other display technologies are becoming more popular in smartphone displays, but LCDs still have a place in the market. They are common in budget to mid-tier smartphones as OLED-equipped models cost more.

Many flagship smartphones use OLED displays, because they're more flexible to implement. OLEDs use a single glass or plastic panel, compared to LCDs which use two. In addition, OLED displays don't need a backlight; this makes the phones thinner and provides deeper blacks because each pixel in an OLED display is individually lit.

If a display in an LCD screen is mostly black with only a small portion lit, the whole back panel is still lit, which causes light leakage on the front of the display. An OLED screen avoids this issue. OLED displays also have better contrast and viewing angles, and use less power.

With a plastic panel, an OLED display can be bent and folded over itself. This can be seen in smartphones such as the Samsung Galaxy Fold, in which the entire device folds. It's also used in the iPhone X, which will bend the bottom of the display over itself so the display's ribbon cable can reach in towards the phone, eliminating the need for a bottom bezel. Folding devices must have plastic front screens that bend. However, this means the display will likely scratch more easily.

Smartphone displays have started taking up more space on the front of a device, with some smartphones having edge-to-edge displays. For example, the iPhone 14 Pro has an 87% screen-to-body ratio, and the Samsung Galaxy Note 10 Plus has a 91% ratio.

In 2019, the Chinese company Xiaomi announced a phone with a screen-to-body ratio of 180.6%. The Mi Mix Alpha's OLED screen was intended to bend around nearly the entire phone, having a small non-screen band reach around the back for the 108-megapixel camera and 12-megapixel telephoto lens. The phone would be turned around so the user can take a selfie, using the back of the display to see themselves. The Mi Mix Alpha turned out to be too difficult to mass produce, and Xiaomi canceled its plans for it.

Smartphone displays usually have refresh rates of 60 Hz, 90 Hz or 120 Hz. Some manufacturers have increased the display's refresh rate as high as 240 Hz. The higher refresh rate makes for a smoother experience because there's less time between each frame. However, this also consumes more battery life.