Global sales of tablet computers are expected to surge this year, driven by Apple's market-leading iPad, but also its smaller-format rivals, market research firm IHS reported on Monday, Sept. 17.

According to IHS, the combined demand for tablets, be they large or small, is projected to reach 126.6 million units shipped for 2012, marking a 56 percent increase from the 82.1 million shipped in 2011.

"Media tablets increasingly are becoming the biggest growth driver in the market for the small and medium display market, said IHS analyst Vinita Jakhanwal, as cited by AFP. "While the nine-inch segment dominated by the iPad will account for the majority of tablet display shipments this year, the fastest-growing portion of the market will [be] the 7.x-inch screens used in products like the Galaxy Tab from Samsung Electronics, the Kindle Fire from Amazon, the Nook Tablet from Barnes & Noble, and other tablet products using the Google Android operating system."

LG and Samsung Electronics remained the main tablet display suppliers, as they make the liquid display panels Apple uses in its iPad. LG also makes displays for Amazon and Barnes & Noble, while Samsung keeps its product for its own tablets. According to IHS, these companies are making significant investments in developing wide-angle technology, improved resolution and power consumption, and better overall performance.

Nine-inch screen tablets will account for nearly 60 percent of units shipped this year, with the iPad as "the uncontested leader," noted IHS. The 7-inch tablets, however, are rapidly cutting into the iPad's dominance on the market. Growth in the segment is forecast to climb to 35 percent from 55.2 million units in 2011.

Shipments of 7-inch tablets account for 32 percent, up from 26 percent in 2011. Sales in the 7-inch segment, which Apple is expected to enter later this year with an iPad Mini, are expected to double from 20.8 million units last year.

Samsung and LG dominate the market with 38 percent and 42 percent market share, respectively, but IHS analysts warned that the companies should beware of other suppliers starting to benefit from the growing tablet market, particularly manufacturers such as Japan's Sharp and Panasonic and Taiwan's AU Optronics and ChiMei Innolux.