Optical and image processing manufacturer; founded 1939 as Van Leer NV's Optical Industry (NV Van Leers Optische Industrie) in Oude Deflt, Delft; renamed during Nazi occupation of Holland as NV Optical Industries' De Oude Delft'; Franke & Co Optik taken over in 1963; expansion into America in 1952 as Old Optical Technology Corporation (oDoc), a joint venture with Aerojet Delft, developing infra-red, night vision and image intensifiers for the military; new division opened in 1970, Delft Electronic Products (DEP). following rationalisation in late 1970s company renamed Oldelft Groep NV (Oldelft Group) in 1985, operating as a holding company; merger of NV United Instrument Factories and Enraf-Nonius Oldelft Group NV in 1990 created Delft Imaging Systems.