Optical beam scanning system having a synthetic center of beam rotation

An optical beam scanning system for scanning the retina of an eye, comprising:

• a front mirror having a motor to orient the front mirror relative to a frame of reference so as to receive and redirect an optical beam in accordance with the orientation of the front mirror;
• a primary intermediate mirror having a motor to orient the primary intermediate mirror relative to the frame of reference so as to receive and redirect the optical beam in accordance with the orientation of the primary intermediate mirror;
• a back mirror having a motor to orient the back mirror relative to the frame of reference so as to receive and redirect the optical beam in accordance with the orientation of the back mirror;
• and
• a controller connected to the front, primary intermediate and back mirrors to orient the front, primary intermediate and back mirrors so that the optical beam received by the front mirror from a given direction is redirected toward the primary intermediate mirror, and is redirected by the primary intermediate mirror toward the back mirror, and is redirected by the back mirror so as to pass through a selected point spaced apart from the back mirror in one of a plurality of selectable different directions such that the optical beam exiting the back mirror rotates about a synthetic center of beam rotation (SCBR), the SCBR being not located at a surface of any of the front mirror, the primary intermediate mirror, or the back mirror.