Patent ID: 7726213

Claim:
A sensor comprising: a structure; a mass that moves relative to said structure, said mass is attached to said structure by a rigid member such that said mass moves around a pivot point on said structure, said pivot point remaining fixed with respect to said structure as said mass moves; a code scale attached to said mass; an imaging system for forming an image of said code scale, said imaging system being fixed with respect to said structure, said imaging system including an image sensor to generate said image of said code scale and a lens positioned between the image sensor and the code scale to focus said code scale onto the image sensor; and a controller that provides an indication of a position of said mass relative to said structure, said controller utilizing said code scale image, said controller being configured to compare said code scale image with an absolute encoding pattern that specifies a displacement of said code scale relative to an equilibrium position or to compare said code scale image with another code scale image to determine a displacement of said code scale that occurred between said code scale image and said another code scale image.