Pentile vs Real-Stripe AMOLED Displays: What's Different?

By Ryan Whitwam

Samsung is moving ahead with Super AMOLED Plus, but what does the Real-Stripe branding mean?

Samsung has a real advantage over some other Android makers in that it has end-to-end manufacturing capacity. Almost everything in a Samsung Android phone comes from factories owned by Samsung, or a subsidiary of Samsung. They have really pushed the proliferation of AMOLED screens in recent years, and the Super AMOLED has found its way into all of Samsung's recent smart phones. Now Sammy is preparing to take the next step with Super AMOLED Plus. The big change here is the arrangement of sub-pixels; PenTile vs Real-Stripe. 


 

The difference between PenTile and Real-Stripe

Pentile sub-pixels
multiple sub-pixels. Your phone's resolution (often 800 or 854x480) is measured in pixels. Each of the sub-pixels is for a certain color-- red, blue, or green. On Samsung's Super AMOLED screens, each pixel is composed of 8 sub-pixels. PenTile refers to the arrangement of these sub-pixel elements. Unlike standard screens, PenTile is in an RG-BG arrangement. So you get one-third fewer sub-pixels in total by repeating the green after each red or blue sub-pixel. These screens are easier to manufacture, and we know that AMOLEDs are not easy to make in the first place.  

RGB sub-pixels 

 

The effect of sub-pixel arrangement

When you look very closely at a Super AMOLED screen, you can see the effect of the PenTile screen. Some colors look almost grainy, or dare we say pixilated. This is more noticeable with warmer colors. Things can look speckled, and text a little more blurry. We will, however, say that Super AMOLED looks better than standard AMOLED screens in the sharpness department.  
 

 
The drawback to Real-Stripe is that the resulting pixels are overall greater in size. That means screen have to be a little bigger to accommodate the expected WVGA resolution. Super AMOLED phones like the Nexus S and Galaxy S had 4-inch screens. The Infuse 4G and Galaxy S2 are running Super AMOLED Plus panels at 4.5 and 4.3-inches respectively. The increased size is because the pixels are larger. We still expect image quality ot be better than Super AMOLED.     
 

What this means for the future

manufacturing technology Samsung is using to produce their screens. Samsung currently employs Fine-Metal-Mask (FMM) technology to manufacture Super AMOLED and Super AMOLED Plus. This is a fine method, but it is expensive and has a printing accuracy of about 15μm (micrometers). Using this technique, Samsung can only make screen with pixel densities of about 200ppi. That's right in line with a 4.3-inch WVGA screen.   
 
Samsung expects to soon switch over to laser-induced thermal imaging (LITI). As you may expect, this is a cheaper and more accurate method of producing AMOLED panels. LITI has accuracy of about accuracy of about 2.5μm. As a result, Samsung expects to be able to produce panels over 300ppi. In case you weren't aware, the iPhone 4 is about 326ppi. That could be an incredible AMOLED screen.  
 
We flat-out like Samsung's Super AMOLED screens, and AMOLED Plus is likely to be a worthy successor. The color vibrancy and black levels are great, and clarity is better than standard AMOLED.  The lingering issues with AMOLED are slowly being eroded as new manufacturing technologies roll out. Samsung phones will probably continue to have some of the most impressive screens out there for the foreseeable future. Let us know what you think about AMOLED panels and the different sub-pixel arrangements. Would you overlook Samsung's other Android issues to lay hands on a Super AMOLED Plus screen?     
 
Image credit: Peter Halasz, Samsung