They acquired TrueSense (= CCD industrial sensors) and now Aptina. Aptina is a small player in mobile, but ok-ish for industrial and DSC (AFAIK, they are supplying the sensor for the Nikon 1" system camera).
I also didn't know On Semi formerly was part of Motorola Semi.
One of the most striking things about this deal is that ON semi is suddenly becoming a destination place for many CMOS image sensor experts. Through a host of acquisions, ON Semi will have both IPs and talents.