FIELD: physics, optics.
SUBSTANCE: invention relates to an image-forming optical system, a sensor for inspecting valuable documents having said optical system and a method of displaying an object point. The optical system has a flat anisotropic retroreflecting portion which specularly reflects radiation components in a first plane of incidence, but retroreflects radiation components in a second plane of incidence. A first display portion forms on the retroreflecting portion an intermediate image of the object point stretched in the form of a line in the second plane of incidence. A second display portion displays an intermediate image stretched in the form of a line to an image point.
EFFECT: compact design.
16 cl, 7 dwg
