 He had been developing a mirror drum-based television, starting with 16 lines resolution in 1925, then 32 lines and eventually 64 using interlacing in 1926.As part of his thesis, on May 7, 1926, he electrically transmitted and projected near-simultaneous moving images on a five-foot square screen.In 1930, German Telefunken engineer Fritz Schröter first formulated and patented the concept of breaking a single video frame into interlaced lines.