An optical position-measurement device includes a reflection measuring standard and a scanning unit, which is movable in relation thereto in at least one measurement direction. The reflection measuring standard has an incremental measuring graduation and a reference marking in at least one reference position. In addition to scanning device(s) for the incremental signal generation, the scanning unit includes for the reference signal generation at least one light source, imaging optics, a diaphragm structure arranged in a diaphragm plane, and a plurality of detector elements. Via the imaging optics, imaging of the reference marking onto the diaphragm structure is implemented. The reference marking is provided on the reflection measuring standard and is integrated into the incremental measuring graduation. In addition, the imaging optics has a variable, object-side focal length along a transversal direction oriented perpendicular to the measurement direction.