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 later joined Wang Laboratories, where, in the late-1980s, he helped develop a personal computer that let users annotate documents with synchronized voice messages and digital pen strokes.
In 2008, after retiring from tech research, he joined a magician and inventor named Mark Setteducati in creating a jigsaw puzzle called Ji Ga Zo, which could be arranged to resemble anyone’s face. “He had a mathematical mind combined with a great sense of aesthetics,” Mr. 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; a 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, have died.
While at Bell Labs, Mr. Knowlton collaborated with several well-known artists, including the experimental filmmaker Stan VanDerBeek, the computer artist Lillian Schwartz and the electronic-music composer Laurie Spiegel. He saw himself as an engineer who helped others create art, as prescribed by Mr. Rauschenberg’s E.A.T. project.
But later in life he began creating, showing and selling art of his own, building traditional analog images with dominoes, dice, seashells and other materials. He belatedly realized that when engineers collaborate with artists, they become more than engineers.
“In the best cases, they become more complete humans, in part from understanding that all behavior comes not from logic but, at the bottommost level, from intrinsically indefensible emotions, values and drives,” he wrote in 2001. “Some ultimately become artists.”