Patent ID: 7230726

Claim:
A scanning unit for a position measuring instrument for optical scanning of a measuring graduation, the scanning unit comprising: a light source that emits light in a direction towards a measuring graduation that generates modified light from said emitted light; a detector that receives said modified light; and a lens array, disposed upstream of said detector and comprising a first group of lenses disposed in a first plane that is oriented such that said modified light intersects said first plane and a second group of lenses disposed in a second plane extending parallel to said second plane, said lens array generates a defined image of a region of said measuring graduation, scanned by said emitted light, on said detector, wherein an image magnification of said lens array is greater than 0 and less than or equal to 2, wherein said first group of lenses are combined in one or more cells that includes a first cell that comprises: a first lens from said first group of lenses; and a second lens from said second group of lenses, wherein said first group of lenses are each disposed one after the other, perpendicular to said first plane and said second plane; and wherein at least some of said modified light first passes through said first lens and then reaches said second lens and wherein said modified light that passes through said first lens does not reach a lens of said second group of lenses that forms a second cell.