Patent ID: 7244928
Filing Date: 2007-07-17
Classification: G01D

Abstract:
1. An optical encoder, comprising: a code strip having a first side, a second side, a first track comprising indicia thereon, and a second track comprising indicia thereon, said code strip being associated with a displacement path with respect to said optical encoder; a light source positioned on the first side of said code strip, said light source directing light toward said code strip; a first detector element positioned on the second side of said code strip so that said first detector element is generally aligned with the first track of said code strip, said first detector element detecting the indicia comprising the first track of said code strip; and a second detector element positioned on the second side of said code strip so that said second detector element is generally aligned with the second track of said code strip, said second detector element being located a spaced distance along the displacement path from said first detector element, said second detector element detecting the indicia comprising the second track of said code strip, wherein the indicia comprising the second track are shifted along the displacement path with respect to the indicia comprising the first track by a distance that is about equal to the spaced distance along the displacement path separating said second detector element and said first detector element.