Abstract: A constant deviation beam scanning apparatus having a rotatable beam deflector with at least one reflective surface thereof lying in a plane that intersects the axis of rotation at an acute angle. One embodiment utilizes a rotatable, truncated, n-sided pyramidal mirror with at least one planar reflective scanning segment located on one of the n-sides of the pyramidal mirror. The pyramidal mirror's truncation surface lies in a plane normal to the mirror's rotation axis and contains at least one planar reflective segment. A constant deviation reflector having two reflective surfaces is positioned so that a collimated beam of light reflected by the truncation surface reflective segment is reflected by one of the constant deviation reflective surfaces to the other reflective surface and then to the at least one planar reflective scanning segment of the pyramidal mirror.

Abstract: A constant deviation beam scanning apparatus having a rotatable beam deflector with at least one reflective surface thereof lying in a plane that intersects the axis of rotation at an acute angle. One embodiment utilizes a rotatable, truncated, n-sided pyramidal mirror with at least one planar reflective scanning segment located on one of the n-sides of the pyramidal mirror. The pyramidal mirror's truncation surface lies in a plane normal to the mirror's rotation axis and contains at least one planar reflective segment. A constant deviation reflector having two reflective surfaces is positioned so that a collimated beam of light reflected by the truncation surface reflective segment is reflected by one of the constant deviation reflective surfaces to the other reflective surface and then to the at least one planar reflective scanning segment of the pyramidal mirror.