Big changes in small displays
Small and medium sized displays (9 inches and smaller in diagonal) are used widely in a variety of medical and industrial equipment, as well as transportation and other infrastructure. Because these applications represent a small fraction of the demand for small-medium displays, buyers and designers need to follow the overall industry trends when considering product availability and capabilities.
The overall market for such displays has long been dominated by mobile phone applications, which account for slightly less than two-thirds of unit demand and slightly more than two-thirds of revenues. Smartphones are increasingly driving changes in the mobile phone market, and will become the largest mobile phone segment in unit terms by 2015. Growing even more rapidly are tablet PCs, which will pass the automotive market this year to be the second-largest small-medium display application in revenue terms. Thus, it is important to understand how the trends in these two market segments are driving display technology and manufacturing.
Smartphone wars: TFT LCD vs. AMOLED
There are currently three key display technologies used in smartphones (Figure 1). The most well-established is the amorphous silicon form of TFT LCD (thin film transistor liquid crystal display), which is the dominant form of flat panel display technology. As smartphones began to take off after the original iPhone, the low-temperature polysilicon (LTPS) form of TFT LCD began to dominate the market, as LTPS enables higher pixel densities, as well as integration of other circuitry – such as driver ICs, touch sensors, and memory – which enables higher performance in a smaller display package. Finally, a few years ago, Samsung started mass production of the active matrix form of organic LED display technology (AMOLED), which enabled it to take increasing share of the growing smartphone display market.
*(See Figure 1)
Starting in 2011, two companies – Apple and Samsung – emerged to dominate the smartphone market; each gained market share in 2012, and now the two account for more than half of all smartphone shipments, as well as setting the standard for product design and technology. Among the most important ways in which the flagship smartphone product lines (iPhone, Galaxy) compete is through the choice of display. Apple’s iPhone has used TFT LCD, in particular LTPS, to set the standard for high resolution, going so far as to brand it “retina display,” as well as to integrate touch functionality into the display itself. Samsung’s Galaxy phones have largely utilized AMOLED technology, which has enabled large, colorful displays, with a different form of integrated touch, but at slightly lower pixel density. In general, LTPS displays are somewhat smaller but have higher pixel density than AMOLED displays (Figure 2). The iPhone retina display had the highest pixel density (324 pixels per inch) when it was first introduced, but the bar continues to be raised, with Japan Display, Inc. and Sharp both recently demonstrating 5 inch full HD (1920 x 1080 or 443 pixels per inch) LTPS panels.
Five companies dominate the smartphone display market – Samsung Display Corp., which makes AMOLED displays and TFT LCDs, and LG Display, Innolux Display, Sharp, and Japan Display, Inc., which all primarily make TFT LCDs, particularly LTPS.
*(See Figure 2a&b)
Tablets – Competition hottest between 7 and 9-inches
The tablet PC market was created by the introduction of the original iPad, which for the first few years dominated the segment, defining a tablet PC as something around 10 inches in diagonal. However, over past few years, several competitors have entered the market in the 7 inch segment, finally joined by Apple with the iPad mini (at 7.85”). The high level of activity has created significant demand for 7-9 inch displays, and also has led to development of new levels of performance. Unlike in smartphones, in this case the clear leader is the a-Si TFT LCD, with LTPS not cost competitive, and AMOLED still struggling in terms of manufacturing cost.
As in smartphones, the trend in tablet PC displays has been toward higher pixel densities, though not as high as in smartphones, due to the longer viewing distance. While the mass market products are in formats such as 1024 x 600/768 and 1280 x 768/800, new devices from Amazon and Barnes and Noble are full HD (1920 x 1080). The dominant makers of 7 to 9 inch tablet PC panels are Samsung Display Corp. and LG Display.
*(See Figure 3)
Riding the wave
From 2010 to 2014, the value of the small-medium display segment is expected to double, from $24 to $48 billion. All of the revenue growth is accounted for by mobile phone and tablet PC displays, as units grow rapidly, average screen sizes and resolution increase, and increasing functionality such as touch capability is integrated into such displays. This revenue growth is associated with a significant amount of technology development and manufacturing capacity. For applications needing small-medium displays, it would be very beneficial to tap into these two segments, riding the waves of improvement.