The appeal to the PA Supreme Court comes just 3 days after Brinkley ruled Meek's side failed to meet its burden of proof. It was a shocking decision given even the D.A. had repeatedly stated Meek deserved a new trial, considering his arresting officer -- the only witness in Meek's 2008 trial -- is a key figure in a massive Philadelphia police corruption scandal.

In legal docs, obtained by TMZ, Meek's lawyers are adamant Brinkley had made up her mind before Meek's hearing concluded earlier this week. Lawyers cite the transcript which they claim shows Brinkley lacking impartiality because "she acted like a prosecutor, not a judge." Interesting ... even the real prosecutor thinks Meek deserves a new trial.

As we reported ... Meek's team accused Brinkley of laughing at one of their key witnesses, but they also point to another fiery exchange triggered after Brinkley said, "... because obviously we know that it's going to go to another court after here." Meek's lawyer, Brian McMonagle, asked if she's implying she'd already made up her mind and realized her decision would be appealed to a higher court. She denied it.