Filmmaker Steven Spielberg says he knows putting a woman in the lead role of an Indiana Jones movie would upset fans, but believes it's time the explorer "took a different form".The role was made famous by actor Harrison Ford, 75.Spielberg nodded when asked if this new-look Jones could be female, and told thesun.co.uk: "We would have to change the name from Jones to Joan. And there would be nothing wrong with that."The 71-year-old has been a vocal champion of the Time's-Up campaign for gender equality in the movie industry, and is no stranger to powerful women.His mother Leah, who died last year aged 97, raised him and his three sisters almost single-handedly because his workaholic engineer father Arnold, now 101, was rarely around.And he has been married to actress Kate Capshaw, 64, since 1991, after meeting in 1984 when she starred in the second Indiana Jones film.He said: "My mom was strong. She had a voice; she had a very strong opinion. I have been very lucky to be influenced by women, several of whom I have just loved madly -- my mom and my wife."Filming for the fifth movie in the Indiana Jones franchise is due to begin in April next year.But Spielberg said: "This will be Harrison Ford's last Indiana Jones movie, I am pretty sure, but it will certainly continue after that."That is when the director will decide on whether to go ahead with "Joan".