The prevailing trend for the production of touch panels has migrated from small-sizes, to medium- and large-size models, as evidenced by the launch of 4-inch mainstream smartphones, Dell's 5- and 7-inch Streak touch-controlled devices, and brisk sales of tablet PCs in 7- to 10.1-inch sizes, according to industry sources.

Taiwan-based touch panel maker TPK Holding is ramping up the ratios of medium- and large-size panels and expects its shipments of 32-inch touch panels to gain momentum starting the third quarter 2011, said company president Tom Sun.

TPK currently produces all sizes of touch panels at its 3G and 4.5G production lines in Ximen, China.

Other makers are developing signage boards built using large-size touch panels, including 32-inch capacitive touch panel models, remarked industry sources.