Display: smartphone terms explained

29 terms. Back to the full glossary.

AMOLED / OLED: A display where each pixel makes its own light, so blacks are fully off and contrast is very high. AMOLED is a type of OLED. LCD panels use a backlight instead. OLED screens usually look punchier in a dark room and let phones offer always-on displays cheaply in battery terms. Trade-offs are possible flicker from PWM dimming at low brightness and, over years, uneven ageing or burn-in with static images. Quality varies a lot between panels, so look at brightness, PWM frequency and colour accuracy rather than the label alone. Related: LCD, PWM dimming and flicker, LTPO display, Always-on display, Contrast ratio.
LCD: A display that lights the whole screen with a backlight and uses liquid crystals to block or pass light for each pixel. Blacks look dark grey rather than fully black. LCDs are common on lower-priced phones and are usually free of low-frequency PWM flicker. They can be bright and colour-accurate, but contrast is lower than OLED and thin bezels are harder to make. Refresh rate and brightness matter more to daily use than the LCD or OLED label. Related: IPS LCD, AMOLED / OLED, Contrast ratio, PWM dimming and flicker.
IPS LCD: In-Plane Switching, a type of LCD panel known for wide viewing angles and fairly consistent colour when viewed off-axis. Most LCD phone screens are IPS or a close variant. IPS panels typically have lower contrast than OLED because the backlight leaks a little in dark scenes. A good IPS panel can still be a sensible choice if you want a screen that is easy on sensitive eyes and costs less. Related: LCD, AMOLED / OLED, Contrast ratio.
LTPO display: A display backplane that can vary its refresh rate, often down to 1Hz for static content, to save battery while keeping high refresh rates for motion. LTPO is found on OLED panels and is most useful for always-on displays and for reading long pages. The saving is real but modest in everyday use, since the screen is only one part of battery drain. Some phones use simpler adaptive refresh with a few fixed steps (for example 60, 90 and 120Hz) that is not LTPO; the practical gap is small for most people. Related: Refresh rate, AMOLED / OLED, Always-on display, mAh.
Refresh rate (Hz): How many times per second the screen redraws. 120Hz looks smoother than 60Hz when scrolling and in supported games. Typical phone values are 60, 90, 120 and 144Hz, with some gaming phones going higher. Higher rates cost some battery unless the panel can drop its rate when content is still. A phone that offers 120Hz is only smooth if the chip and software keep up, and many games cap at 60 or 90 frames per second regardless of the screen. Related: LTPO display, Touch sampling rate, Game frame rate, mAh.
Touch sampling rate: How many times per second the touch layer checks for your finger. It is separate from the refresh rate and affects how quickly touch input is registered. Typical values are 120 to 480Hz, and some gaming phones quote higher. Makers often quote an instantaneous peak (for example in a game mode) rather than the everyday rate, so read the fine print. It matters most in fast competitive games and less in normal use. Related: Refresh rate, Gaming phone, Game frame rate.
Nits (peak brightness): A unit of brightness (candela per square metre). Makers quote peak brightness under different conditions, often a small part of the screen in HDR, so figures are not directly comparable across brands. Brightness in sunlight is what matters outdoors, which is common in India. A screen with a high manual or typical brightness and a strong high-brightness mode is easier to read in daylight. Treat a single big number with caution until you know whether it is typical, high-brightness mode or HDR peak. Related: Typical vs peak brightness, HBM, HDR10+, Dolby Vision.
Typical vs peak brightness: Typical brightness is what the whole screen can sustain in normal use. Peak brightness is a short-lived maximum, often measured on a small bright patch of an HDR image. Peak figures can be several times higher than what you see when the whole screen is white. Some makers also quote a laboratory figure for a tiny window. A useful spec sheet gives at least two figures: manual maximum and high-brightness or HDR peak. If only one number is given, assume it is the most flattering one. Related: Nits, HBM, HDR10+.
HBM (high brightness mode): A mode where the screen temporarily goes brighter than its normal maximum, usually triggered automatically in strong sunlight or for bright HDR highlights. HBM generally cannot be held indefinitely because of heat and panel wear, so brightness may step down after a while. It is the figure that tells you how readable the screen is outdoors. It is not the same as the brightness slider maximum. Related: Nits, Typical vs peak brightness, AMOLED / OLED.
PWM dimming and flicker: Many OLED screens lower brightness by switching pixels on and off very quickly instead of lowering the current. The switching rate is the PWM frequency. At low frequencies, typically a few hundred Hz, some people notice eye strain or headaches, especially at low brightness at night. Higher PWM rates, typically 1000Hz or more, are easier on sensitive eyes, and some phones offer DC-like dimming options. If you are sensitive to flicker, look for the PWM figure and independent measurements, and consider an LCD. Related: AMOLED / OLED, DC-like dimming, LCD, Eye-comfort and low blue light modes.
DC-like dimming: A way of lowering brightness that avoids or reduces the on-off switching of PWM, intended to cut visible flicker at low brightness. Implementations differ: some change the current, others raise the PWM frequency. The name says little about how well it works, so independent flicker measurements are more reliable than the marketing term. Related: PWM dimming and flicker, AMOLED / OLED, Eye-comfort and low blue light modes.
Eye-comfort and low blue light modes: Software modes that warm the screen colour at night to reduce blue light, and sometimes certifications about flicker or blue-light handling. A warm night mode can make late-night reading more pleasant, but there is no strong evidence that blue light from phones damages eyes. Certifications and labels vary in how strict they are. Do not pay extra for the label alone; PWM frequency and brightness range matter more. Related: PWM dimming and flicker, DC-like dimming, Nits.
HDR10: The basic, open HDR video standard. It uses fixed metadata for a whole video and a 10-bit signal to describe a wider brightness and colour range. Support means the phone can play HDR10 video, not that the screen is bright enough to show it well. Streaming apps also need to be certified for HDR on a given phone. Look at peak brightness and 10-bit panel depth for a sense of real quality. Related: HDR10+, Dolby Vision, Colour bit depth, Nits.
HDR10+: An HDR format that adds scene-by-scene brightness information to HDR10, so the screen can adjust tone mapping through a video. It is a royalty-free alternative to Dolby Vision. Content availability depends on the streaming service and on the phone being certified. A phone with HDR10+ but a dim panel will not show much visible benefit. Related: HDR10, Dolby Vision, Nits.
Dolby Vision: A proprietary HDR format by Dolby that uses dynamic metadata and up to 12-bit colour data to tune picture scene by scene. Phones with the badge can play Dolby Vision streams in supported apps, and some can also record Dolby Vision video. Benefit depends on the panel: bright, colour-accurate screens gain most. Do not confuse it with Dolby Atmos, which is an audio format. Related: HDR10+, HDR10, Dolby Vision video recording, Dolby Atmos.
Colour gamut: The range of colours a screen can show. sRGB is the standard for most web content; wider gamuts such as DCI-P3 can show more saturated colours. A wide gamut only looks right when software maps colours properly, otherwise everything can look oversaturated. Many phones offer a natural mode close to sRGB and a vivid mode. Percent-coverage claims depend on the measuring method, so treat them as a rough guide. Related: DCI-P3, Delta E, Colour bit depth.
DCI-P3: A colour space originally for cinema that is wider than sRGB. Many premium phone screens cover most or all of it. A claim such as 100% DCI-P3 means the screen can reproduce that whole range, not that photos look more accurate. For accurate colour you also need a good Delta E and correct colour management in the apps you use. Related: Colour gamut, Delta E, Colour bit depth.
Delta E (colour accuracy): A measure of how far a displayed colour is from the intended one. Lower is better. A Delta E under about 2 is typically considered excellent and hard to notice. Values depend on the colour mode tested, so a figure for the accurate mode says little about the vivid mode. It matters most if you edit photos or care about natural skin tones. Related: Colour gamut, DCI-P3, Colour bit depth.
Colour bit depth (8-bit, 10-bit): How many shades each of red, green and blue can have. 8-bit gives about 16.7 million colours; 10-bit gives about 1.07 billion. More bit depth reduces visible banding in gradients such as skies. Some panels reach 10-bit using dithering rather than true 10-bit. The benefit is visible mainly with HDR video and well-tuned content. Related: HDR10, Dolby Vision, 10-bit video, Colour gamut.
Resolution names (HD+, FHD+, QHD+, 1.5K, 2K): Marketing names for screen pixel counts. HD+ is typically around 1600 by 720, FHD+ around 2400 by 1080, and QHD+ (often called 2K) around 3200 by 1440. 1.5K sits between FHD+ and QHD+. Exact pixel counts vary with screen shape. FHD+ looks sharp on most phone screens, and the jump to QHD+ is hard to see in normal use while costing battery. HD+ on a larger screen can look slightly soft on text. Related: Pixel density, Refresh rate, mAh.
Pixel density (ppi): Pixels per inch: the screen resolution divided by its diagonal size. Above roughly 400 ppi, individual pixels are hard to see at normal viewing distance. A 1080p phone screen of about 6.7 inches is around 400 ppi, and HD+ at the same size is around 260 ppi. Higher ppi gives marginal visible gain beyond about 400 for most people. Sharp text depends on more than ppi, including sub-pixel layout. Related: Resolution names, AMOLED / OLED.
Contrast ratio: The ratio between the brightest white and the darkest black a screen can show. OLED panels can turn pixels fully off, so their stated contrast is often huge or infinite, which is a theoretical figure. LCDs typically have a much lower real contrast. Compare it in a dim room, where differences are most visible. Related: AMOLED / OLED, LCD, IPS LCD.
Curved vs flat display: A curved display bends over the side edges of the phone; a flat display does not. Some phones use a slight curve, called 2.5D, only in the glass. Curved edges look premium and make the phone feel thinner but can cause accidental touches, glare along the edge and costlier repairs. Flat screens are easier to protect with a screen guard and are usually cheaper to fix. Pick based on how you hold the phone and whether you use a case. Related: Gorilla Glass, Screen protector and pre-applied film, AMOLED / OLED.
Gorilla Glass (types): A family of toughened cover glass made by Corning. Newer versions such as Victus improve drop and scratch resistance over older ones. Glass can be strong against drops or against scratches, rarely both. Names and version numbers are marketing for an improvement over the maker's own previous version. Even the best glass can crack on a bad drop, so a case and a screen protector still help. Related: Gorilla Glass Victus, Ceramic Shield, Drop rating and drop resistance, Screen protector and pre-applied film.
Gorilla Glass Victus: A generation of Corning cover glass marketed for improved drop resistance on hard surfaces and better scratch resistance than earlier versions. Later Victus versions are marketed with further gains. Always check whether the glass covers only the front or also the back and camera lenses. Glass quality is one part of durability alongside frame and design. Related: Gorilla Glass, Ceramic Shield, Drop rating and drop resistance.
Ceramic Shield: Apple's name for a front glass that has ceramic crystals mixed into it to improve toughness. It is a product name, not a general category, and the glass is made with a glass partner. The claim is about drop resistance, not that the screen cannot scratch. Related: Gorilla Glass, Gorilla Glass Victus, Drop rating and drop resistance.
Screen protector and pre-applied film: A thin film or tempered glass sheet over the screen to take scratches. Many phones ship with a thin film already applied. A pre-applied film is usually a basic plastic layer and may scratch or peel easily. Glass protectors are tougher but can interfere with in-display fingerprint sensors if poorly made. Buy one sized for your phone, especially for curved screens. Related: Gorilla Glass, Curved vs flat display, In-display fingerprint sensor.
Always-on display: A low-power screen mode that shows the time, notifications or a wallpaper while the phone is locked. It works best on OLED, where only a few pixels are lit, and especially with a variable refresh rate. It does use some battery over a day, and many phones let you set a schedule or tap-to-show option. Related: AMOLED / OLED, LTPO display, mAh.
Punch-hole, notch and under-display camera: Ways of fitting the front camera: a small hole in the screen (punch-hole), a cut-out at the top (notch), or a camera hidden under the display pixels. Punch-hole is the most common design. Under-display cameras hide the lens but typically give lower selfie quality because light passes through the screen. Notch designs may house face unlock sensors. Related: Selfie (front) camera, Face unlock, AMOLED / OLED.