On November 24, 2009, HannStar and LG Display signed a patent cross-license agreement covering TFT LCD technology that is effective retroactively to January 1, 2009 and last until the end of 2013. HannStar is one of few LCD manufacturers that make use of IPS technology to produce large-size TFT LCD panels. The other two are LG Display and IPS Alpha. Source: DIGITIMES