The 23-year-old completed the move on Friday, and will be included in the squad to face Doncaster on Saturday.
He spent a month on loan at League One rivals Carlisle earlier in the season, scoring once in five games for the Cumbrians.
Beckford began his career as a trainee at Chelsea, but dropped into non-league with Wealdstone after failing to make the grade at Stamford Bridge.
He returned to the professional ranks in March 2006 with a move to Leeds.