“this device features a 7-inch AMOLED panel which supports 120Hz of refresh rate”. You must have read this alot if you are a phone enthusiast or when looking for a phone to buy.
You know that it is a type of screen,but do you really know what it is or what technology is behind it. Well just relax and allow me to explain.
I will explain the different types of smartphone screens and the technology behind them first, then i’ll explain refresh rate, touch sampling rate, and LTPO tech.
Liquid crystal display (LCD) tech was developed as an alternative for cathode ray tube (this is what those fat 90’s TV use).
This technology uses a layer of liquid crystals, together with polarizers to control light. this technology has been in existence for long time.
There are two basic types of LCD screens which are IPS LCD and TFT LCD with the former being the most popular in the smartphone industry.
In-plane switching (IPS) LCD is a type of LCD in which the layer of liquid crystals is put in between two sheets of glass. This tech was designed to sole the issue of low-quality color reproduction. It was developed by japanese company, Hitachi Ltd.
One of the advantages of IPS LCD which people tend to overlook is that it give the accurate color of images, unlike AMOLED panels. This is the most popular among entry-level and mid-range phones.
Thin Film Transistor (TFT) LCD is a type of LCD that uses thin-film-transistor technology to improve image qualities such as making them more addressable and contrast.
Organic light emitting diode (OLED) is a LED in which a sheet of organic compound gives light in response to electric current. This display type is most popular among flagship devices. Your iPhones make use of OLED screens.
Active Matrix Organic Light Emitting Diode (AMOLED) is by far the most popular screen display, i think Samsung began the use of AMOLED screens first.
This is basically an OLED technology in which each of the pixels are constantly switching and generating light, creating an Active matrix.
AMOLED displays have major advantages which include the ability to have a higher refresh rate, more brightness for direct use under sun, and consuming less power.
super AMOLED Display
This “super” version of AMOLED was created by Samsung and it’s still in development. The difference is that the touch layer is inside the display instead of being on top of it,just like normal AMOLEDs.
It fixes the brightness and color issue which AMOLED brings.
now i will explain some regularly used terms widely used when talking about displays.
Refresh rate is the measure of the number of times the content of your screen refreshes per second. It is measured in Hertz (Hz) and varies.
60Hz refreshes 60 times per second, 90Hz refreshes 90 times per second, and 120Hz refreshes 120 times per second.
This is mostly important to gamers and it can be a bit power consuming.
touch sampling rate-
is the number of times a display can refresh itself to register a user touch input in one second, and it is also measured in Hertz.
LTPO is an acronym for Low-Temperature Polycrystaline Silicon, and it is a tech which was developed by apple, and is currently used in the apple watches.
Samsung and other major manufacturers decided to adopt that tech because it can reduce the refresh rate of a device from as much as 144Hz to 1Hz. it was the tech which saved screens from consuming too much power.