Feeds
The actor claimed Indiana Jones and the Kingdom of the Crystal Skull would shed fresh light on the adventurous archaeologist.
He told ABC: "He's a guy who is pretty clear from the beginning. He has not changed so much between films.
"But we've learned more about him through various plot devices, such as the introduction of his father. And we'll learn something more about him in this film.
"I think it's required. If you're going to bring back a character, you'll have to supply the audience with something more and different. The adventure is very, very important. But it's interesting to discover a facet of the character that perhaps you hadn't explored before."
The fourth instalment of the action-adventure franchise premieres at the Cannes Film Festival on May 18.
It is the first movie in the series since 1989, though Ford insisted it wasn't difficult getting to grips with the role again.
He added: "It's as though you put on that hat, the leather jacket, the bag, the whip, the gun - or even the schoolteacher's suit - and it comes back to you."
