INVENTOR OF THE ENCODING PROCESS ESSENTIAL TO FAX MACHINES
Major and graduation year: Electrical Engineering, BS ’67; MS ’68; PhD ’71
Location: Cedar Rapids, Iowa
Sparking interest: Alumnus David C. Nicholas had always been interested in science. Before he came to Iowa State in the early 1960s, he had participated in several science fairs and had an interest in ham radio. He thought about majoring in chemistry, pharmacy, or electrical engineering. Luckily for him and office workers everywhere, he chose electrical engineering.
Important fax: As part of his PhD work, Nicholas developed a filler and synchronization sequence for data-compressing Huffman codes—a process to more efficiently convert text into digital information for the fax machine. “My dissertation involved parsing linear delta-modulated voice at 50 kbps into 7 bit words, and then re-encoding these using a Huffman code to obtain 20 to 40 percent compression in real time with minimal buffering,” Nicholas explains. “So I built a simple computer interface, and I would push my delta modulation and recording equipment on a cart from Coover over to the chemistry building and use their computer for real-time compression. I had 140 microseconds to process a word, which was about 140 instructions, and I wrote code to do it in about 120.”
Prize patent: His work was patented, and by the 1980s, almost every fax machine manufacturer worldwide used Nicholas’ patented method in their fax machines. Iowa State University licensed the technology to 24 fax machine manufacturers, and with approximately $5 billion in fax sales worldwide between 1985 and 1990, this technology generated more than $36 million in income for Iowa State. Nicholas received a portion of the patent proceeds, and the ECpE department also received a portion, which it used to create the endowed David C. Nicholas Professorship in Electrical and Computer Engineering. The patent is Iowa State’s highest earning patent ever.
Career success: After graduating from Iowa State in 1971, Nicholas worked full-time as an engineer at Rockwell Collins for 38 years. At Rockwell Collins, he worked in the Advanced Technology group and worked on the development of an Automatic Call Distribution (ACD) system, which he believes was the first commercial digital telephone switching system in the world. He says the system was used by most of the major airlines as an ACD, and by MCI and ITT as a tandem switch. The switch also was used by the Royal Netherlands Air Force in a redundantly connected military system, which was mutually synchronous, a part of which is the subject of U.S. patent no. 4,144,414. He retired from Rockwell Collins in 2009.