Rotatable mirror assembly for optical path reversal in a laser scanning machine

A method of reversing and aligning a laser beam in a machine, said method comprising the steps of:

• providing a plurality of reflective surfaces;
• orienting said reflective surfaces at at least one angle relative to each other;
• providing a lens having an optical axis;
• directing the laser beam in a first direction such that the laser beam sequentially:
• impinges upon a first of said reflective surfaces;
• reflects off of said first reflective surface;
• impinges upon a last of said reflective surfaces;
• reflects off of said last reflective surface in a second direction substantially parallel to and opposite said first direction;
• and
• impinges upon said lens;
• providing a pivot axis substantially parallel to each of said reflective surfaces;
• and
• pivoting each of said reflective surfaces about said pivot axis by a substantially equal angle to thereby cause the laser beam to be substantially coincident with said optical axis of said lens after reflecting off of said last reflective surface.