Abstract: A reflective metrological scale has a scale pattern of elongated side-by-side marks surrounded by reflective surface areas of a substrate, which may be a nickel-based metal alloy such as Invar® or Inconel® and may be a thin and elongated flexible tape. Each mark has a furrowed cross section and may have a depth in the range of 0.5 to 2 microns. The central region of each mark may be rippled or ridged and may be darkened to provide an enhanced optical reflection ratio with respect to surrounding reflective surface areas. A manufacturing method includes the repeated steps of (1) creating a scale mark by irradiating a surface of the substrate at a mark location with a series of overlapped pulses from a laser, each pulse having an energy density of less than about 1 joule per cm2, and (2) changing the relative position of the laser and the substrate by a displacement amount defining a next mark location on the substrate at which a next mark of the scale is to be created.

Abstract: A flexible optical marker is applied to an optical scale substrate to make an optical scale assembly for an optical position encoder. The marker may be a limit marker, index marker, or other type of marker. The marker substrate may be a plastic film such as polyester, singulated from a “recombine” roll created by a web process. The marker has a microstructured pattern on one surface that is covered with a reflective metal coating. The marker also has an adhesive layer and is affixed to the optical scale substrate by a process of aligning the marker to an edge of the scale and then applying pressure to the upper surface of the marker. The marker may be applied with a handle portion that is separated from the marker after the marker is affixed. The marker may be especially useful with a flexible scale substrate such as a metal tape substrate.