Patent ID: 7903262

Claim:
An optical position measuring arrangement for determining relative positions of a first object and a second object, which are movable with respect to each other in a measuring direction, wherein a reference pulse signal can be generated in at least a reference position, the optical position measuring arrangement comprising: a scale connected with said first object, said scale comprises: a reference marking at said reference position; a plurality of graduated areas, which are arranged aperiodically in said measuring direction and have different optical properties, wherewith respective additional structures are arranged in said measuring direction adjacent to said reference marking, which extend in said measuring direction and minimize secondary maxima in said reference pulse signal, wherein said additional structures comprises two tracks comprising a first optical property, between which a graduated area comprising a second optical property and extending in said measuring direction is arranged, wherein rectangularly-shaped damping areas are introduced into said additional structures and extend perpendicularly in relation to said measuring direction; and a scanning unit movable in relation to said scale in said measuring direction and is connected with said second object, said scanning unit comprises: a light source; and a reference pulse detector arrangement comprising detector elements, whose geometric arrangement is matched to said reference marking for generating said reference pulse signal.