Gadget Blog

They come in all shapes and sizes. and abbreviations too

LCD display: In the nineties,  when the mobile phone was knocking on our doorsteps, phones used  to have single or double line LCD panels as in digital
watches.
The term LCD refers to the initial form of display in mobile phones.
It is a flat panel which uses two sheets of polarizing material with a liquid crystal solution between them. LCD displays were used acorss several phone brands and are still considered excellent for reading text. 








TFT display: Colour LCD displays have two variants-passive and active matrix display. The active matrix display is also known as thin film transistor or TFT display as it uses thin film transistor technology and is made from a thin film of amorphous silicon accumulated on a glass panel. TFT based LCD panels are  more popular than passive LCD because they use  a grid of transistors to hold charge for a limited period of time.

Due to the switching action of transistors, only the desired pixel receives a charge and holds it until the next refresh cycle, thus enhancing the image quality. TFT based LCD was found in early Nokia handsets and is still found in handsets the like Sony Xperia Z.

Super LCD: Another form of LCD display, seen in devices like HTC Sensation, is Super LCD. It  is basically a TFT LCD display with lower power consumption compared to other LCD panels.


An OLED display has faster response  time, wider viewing angles, more flexibility,  higher contrast ratio and looks brighter  than an LCD panel. OLED or Organic Light  Emitting Diode is a film of organic com- pound which emits light in response to an  electric current. It is of two types PMOLED  and AMOLED. The latter is more popular  and is widely used in smartphone displays.

It uses a thin-film transistor backpane  to switch each individual pixel on or off.  AMOLED or Active Matrix Organic Light-Emitting Diode is a hybrid display technology which pairs a TFT display with an  OLED display. It offers high image quality,  higher resolution, larger display sizes, con- sumes less power and doesn’t need a back- light. The Nokia Lumia 820 comes with an  AMOLED display.

Displays: as defined by manufacturers

Super AMOLED: Super AMOLED is a term used by Samsung and is nothing but  an AMOLED display with an integrated digitizer and is brighter and more power  efficient than AMOLED. Samsung later created versions of super AMOLED like Super  AMOLED Plus and Super AMOLED HD. The Samsung Galaxy S III and Galaxy Note 2  are  Super AMOLED based mobile phones.


Retina display: Apple started  the trend of calling displays with  high pixel  density,  which made  individual  pixels invisible to the  human eye,  as Retina  displays.
 
The pixel  density varies according to the  size of the  display.
 
For larger  display  devices like  an iPad, a  retina display would have 264ppi and  in smaller ones like and iPhone it  will be 326ppi. Any LCD display with  similar or more pixel density can be called a retina display. 

Clear Black display: Clear Black is not a  new display technology like AMOLED. Instead  it uses a reflection blocking  polarizer to  improve display quality  by enhancing  the contrast of  the screen. It  improves colour  vividness,  increases wide  viewing angles  and consumes  less battery.



Clear Black can  be found on  both AMOLED  and LCD panels. The display  was announced  by Nokia and  is showcased  in Nokia Lumia  smartphones.


Nova display: Nova is an LCD dis- play promoted by LG in the Optimus  Black. It claims to offer 700 nits, making it very bright indeed. and is also  believed to be energy efficient. An  iPhone screen offers around 500nits.

Touchy Displays

Capacitive display: The iPhone made the capacitive  touchscreen the rage it is today. It supports multi-touch and  allows more than two touch gestures simultaneously to per- form multiple functions. It is made of single layer glass coated by a transparent conductive material. When the display is  touched, the screen uses the conductivity of the human body  as an input, affecting the screen’s electrical field. Almost all  smartphones and tablets today have a capacitive display.  


Resistive display: They might be criticised today but resistive touchscreens were the first touchscreens to be seen on  mobile devices. These displays are called resistive as they  are based on resistance and are made of two flexible sheets  separated by an air gap. When pressure is applied on the touch- screen, the two layers come in contact. The vertical and hori- zontal lines on the sheet register the precise location of touch.
 
Resistive displays function on applying pressure on the display,  and work well with  styluses and finger nails. Some consider  it to be outdated but it is still found in many entry-level smart- phones and tablets.