As J.J. Evans on the sitcom "Good Times," Walker shouted, "Dy-no-mite!" on every episode from 1974 to 1979.
Director John Rich came up with the phrase, but both Walker and executive producer Norman Lear were skeptical about it.
At a Television Critics Association meeting Tuesday, Walker said he told Rich that without a story line, viewers wouldn't buy him saying the phrase because they weren't that stupid. But Rich told him that they were. Eventually, the phrase caught on and people waited for him to say it.
Walker says that expectation never bothered him when he was performing at comedy clubs.
The 66-year-old Walker continues to tour the country with his standup act. He appears in Season 4 of the "Pioneers of Television" series that debuts April 15 on PBS.