The main character was a young guy, a miner. The bad guy that ran the mining asteroid looks kinda like Darth Vader and he steals the main character's girlfriend, so the hero embarks on a mission to free her and eventually fights the bad guy. I watched this movie in theaters between 1982-1986 at the latest. The main detail that sticks out for me was that the mining laser was used as a weapon.
It sounds like the movie Starchaser: The Legend of Orin. In the description they talk about mining and the fact there it has a lot of similarities to Star Wars.