Abstract: A retroreflectometer for non-contact measurements of optical characteristics of retroreflective materials from a range of distances includes a light source for emitting a light beam; a first moving mirror assembly for scanning the light beam; a collimating lens for collimating the scanning light on an illumination spot on the surface of the DUT; an imaging lens for receiving a reflected scanning light comprised of the collimated scanning light reflected from the surface of the DUT; a second moving mirror assembly for controlling a predetermined observation angle, wherein the first moving mirror assembly and the second moving mirror assembly moved in synchronization to maintain concentricity of the illumination spot on the surface of the DUT; a light collector for collecting the reflected light from the second moving mirror assembly; a processor including a memory for determining the optical characteristics of the surface of the DUT responsive to the collected reflected light.

Abstract: A retroreflectometer for non-contact measurements of optical characteristics of retroreflective materials from a range of distances includes a light source for emitting a light beam; a first moving mirror assembly for scanning the light beam; a collimating lens for collimating the scanning light on an illumination spot on the surface of the DUT; an imaging lens for receiving a reflected scanning light comprised of the collimated scanning light reflected from the surface of the DUT; a second moving mirror assembly for controlling a predetermined observation angle, wherein the first moving mirror assembly and the second moving mirror assembly moved in synchronization to maintain concentricity of the illumination spot on the surface of the DUT; a light collector for collecting the reflected light from the second moving mirror assembly; a processor including a memory for determining the optical characteristics of the surface of the DUT responsive to the collected reflected light.