Vacuum mold apparatus, systems, and methods for forming curved mirrors

A method of forming a curved mirror for a heads-up display includes providing a mirror preform including a first major surface, a second major surface, and a minor surface connecting the first and second major surfaces. The minor preform has a central portion and a peripheral portion surrounding the central portion. The method includes disposing the minor preform on a mold having a concave surface facing the second major surface and within a housing that surrounds at least a portion of the minor surface, a space being defined between the concave surface and the second major surface with a perimeter of the space being bounded by the housing, the mold comprising a ditch-type vacuum line along a periphery of the concave surface underneath the peripheral portion. The method also includes providing vacuum pressure to the space via the ditch-type vacuum line to conform the mirror preform to the concave surface.