Dr. Knowlton remained at Bell Labs until 1982, experimenting with everything from computer-generated music to technologies that allowed deaf people to read sign language over the telephone. He then joined Wang Laboratories, where in the late 1980s he helped develop a personal computer that allowed users to annotate documents with synchronized voice prompts and digital pen strokes.
In 2008, after retiring from technological research, he joined a magician and inventor named Mark Setteducati to create a puzzle called Ji Ga Zo, which could be arranged to look like anyone’s face. “He had a mathematical mind combined with a great sense of aesthetics,” Setteducati said in a phone interview.
In addition to his son Rick, Dr. Knowlton is survived by two other sons, Kenneth and David, all from his first marriage, which ended in divorce; one brother, Fredrick Knowlton; and a sister, Marie Knowlton. Two daughters, Melinda and Suzanne Knowlton, also from his first marriage, and his second wife, Barbara Bean-Knowlton, died.
While at Bell Labs, Mr. Knowlton collaborated with several well-known artists, including experimental filmmaker Stan VanDerBeek, computer artist Lillian Schwartz, and electronic music composer Laurie Spiegel. He saw himself as an engineer who helped others create art, as prescribed by Mr. Rauschenberg’s EAT project.
But later in life he began creating, showing and selling his own works of art, constructing traditional analog images with dominoes, dice, seashells and other materials. He realized belatedly that when engineers collaborate with artists, they become more than engineers.
“At best, they become more complete humans, in part because they understand that all behavior comes not from logic but, at the lowest level, from inherently indefensible emotions, values and drives” , he wrote in 2001. “Some end up becoming artists.”