LCD, LED, Super AMOLED, IPS, S-LCD: Decoding the Smartphone Display

I am sure most of you might be currently owning or planning to own a smartphone. Well if you are planning to buy one, you might have decided your budget, shortlisted phones from some big leading smartphone manufacturers and then proceeded to the showrooms to make your purchase. Then, you would have started wondering what the heck was going on when the salesman would have started blabbering about the different kinds of displays. He would have used the terms LCD, AMOLED, S-LCD, Super AMOLED, Retina Display, TFT blah..blah..blah.. This post is to make you understand what the blah..blah..blah exactly means. Don't worry... I am going to use the most layman language possible. :-)

You already have an idea of the now-almost-extinct CRTs (Cathode Ray Tubes) that once occupied a sizeable space in your living room. Basically, the technology used inside the CRT was such that it made TVs very bulky as a lot of components were used. The other major disadvantages were that the CRTs made use of phosphor which caused 'Image Burn-in' (Permanent discoloration of parts of the display) and as many parts were used to manufacture CRT, repairing it was a very complex process. Not to mention the kind of power they consumed.

To overcome such problems, people started manufacturing LCDs (Liquid Crystal Displays). LCDs not only overcame all the traditional problems faced with the CRTs but also led to better resolution images being outputted on the screen. Now, one major thing to be remembered is that the LCD panels do not produce light of their own and they need an external lighting mechanism to be effective. 

There are two types of LCDs, Passive Matrix LCDs and Active Matrix LCDs. Now, am not going to explain to you the actual working of these technologies but you should just remember that Active Matrix LCDs reproduce better colors and offer better viewing angles than Passive Matrix LCDs. An example of the Active Matrix LCD is the TFT LCD (Thin Film Transistor LCD). The other important variant, an improvement over the TFT LCD which is now very popular in the market, is the IPS TFT LCD (In-Plane Switching TFT LCD). Your very own Apple's latest generation of iPhones use this technology. It is marketed by Apple as a 'Retina Display' which is nothing but a display that contains so many pixels (326 pixels per inch to be exact) that an eye cannot distinguish individual pixels when viewed from a particular distance. Of-course this is based on the assertion that 300 pixels per inch at a distance of 12 inches from the eye is the maximum amount of detail that a human eye can perceive. LG manufactures this display for Apple under an exclusive contract.

Right. So you now know about few technologies. Good. As I already said, LCDs by themselves cannot produce light and they need an external lighting mechanism for the images produced by LCDs to be visible. Now, as smartphones began becoming popular, manufacturers understood that some things in LCDs can easily be worked upon. ONE. Use materials that can emit light by themselves. TWO. Reduce the size of the display panel. THREE. Increase the image quality. Manufacturers understood that by improving upon these things they can actually improve one of the most desired characteristics of today's smartphones: Battery-Life.

So, they began using LED (Light Emitting Diode). Actually, the technology that became most popular is a variant of LED i.e. OLED (Organic Light Emitting Diode). This is simply a display technology that makes use of material through which if current passes, emits light. Now, as LCDs have 'Active Matrix' variant, the OLED also has a variant which is now used in leading smartphones: Active Matrix OLED now widely known by the name of AMOLED. Samsung's Galaxy S uses Super AMOLED panels and it's latest generation smartphone: the Galaxy S2 uses Super AMOLED plus. The difference between Super AMOLED and Super AMOLED plus is that Super AMOLED plus uses more sub-pixels per pixel, is more efficient and produces better colors than the Super AMOLED panel.

Currently a new range of displays called HD displays are arriving on the market. Actually, the terms HD and 720p display are being interchangeably used and thankfully both essentially imply a similar display (at least for now!!). HD displays imply display having resolution greater than 1280*720 pixels (length * breadth). The underlying technology hasn't changed. It's just that they are being marketed by quoting their resolutions as their USP. The Samsung Galaxy Nexus and the HTC Rezound are supposedly packing these displays although in different sizes. While the Galaxy Nexus is having a 4.65 inch screen, the HTC Rezound has a 4.3 inch screen. And as you might have rightly guessed by now, the pixel density (pixels per inch) would be greater in the HTC Rezound than the Galaxy Nexus. Just remember that when I am talking about the screen length I am essentially talking about the length of the diagonal of the display. Another device soon hitting the markets, the Samsung Galaxy Note having a 5.3 inch screen has a resolution of 1280*800 pixels and it is being marketed as Super AMOLED HD panel.

The last category of displays about which you might have frequently heard is S-LCD. S-LCD (Super LCD) is being manufactured by a joint-venture company which has Samsung and Sony as it's partners. These panels are an improvement over traditional LCD display panels but are not essentially better than AMOLED display panels. They are being chiefly used by HTC as the demand for AMOLED panels has been far outstripping their supply in the current market. All the latest generation HTC smartphones use the S-LCD panels.

So, that's it. I think you are now empowered to make an informed decision. Stay tuned..!!!