Patent ID: 6856464

Claim:
A prism system for splitting/combining different colors of light comprising: a first prism element having a face for projecting and receiving a first color of light; a first surface supported substantially parallel and spaced to form an air gap having a length A1 from said face of said first prism; a first light path through said prism for said first color having a glass path length G1 through said prism system such that the total path length T for said first color is equal to the length of the air gap A1 plus the glass path length G1 (T=A1+G1); another prism element having a face for projecting and receiving another color of light; another surface supported substantially parallel and spaced to form an air gap having a length A2 from said face of said another prism element; and another path through said prism system for said another color having a glass path length G2 that is different from glass path length G1, glass path length G2 selected such that the total path length T for said another color is the same as the total path length T of said first color (A2+G2=T=A1+G1).