Optical sensing apparatus for detecting linear displacement of an object and method of operation thereof with detector matrix and centroid detection

A method of sensing linear displacement of an object between first and second locations along an axis comprising the steps of:

• providing an incident light beam to a reflector affixed to said object such that said reflector reflects said light beam onto a grouping of photo-receptors in a two-dimensional array of photo-receptors;
• determining a first centroid of the reflected light beam on a first group of said photo-receptors of said array of photo-receptors when said object is situated at said first location;
• determining a second centroid of the reflected light beam on a second group of said photo-receptors of said array of photo-receptors when said object is displaced to said second location;
• and
• calculating the displacement of said object between said first and second locations by determining the difference between said first and second centroids.

A method of sensing linear displacement of an object along an axis comprising the steps of:

• affixing a mirror to said object such that when said object is displaced along said axis from a first location to a second location said mirror also moves along said axis;
• providing a light beam from a stationary source to said mirror such that said light beam is reflected by said mirror onto a grouping of photo-receptors in a two-dimensional array of photo-receptors;
• determining a first centroid of the light beam on a first group of said photo-receptors of said array of photo-receptors when said object is situated at said first location;
• determining a second centroid of said light beam on a second group of said photo-receptors of said array of photo-receptors when said object is displaced to said second location;
• and
• calculating the displacement of said object between said first and second locations by determining the difference between said first and second centroids.

A method of sensing linear displacement of an object between first and second locations along an axis, said method comprising the steps of:

• projecting a light beam onto said object, said light beam being projected along an incident light path;
• reflecting said light beam from a mirror affixed to said object and situated in said incident path, said light beam being reflected along a reflective light path;
• intercepting the reflected light beam with a two-dimensional array of photo-receptors situated in said reflective light path, such that said reflected light beam impinges on a grouping of photo-receptors in said two-dimensional array;
• determining a first centroid of said reflected light beam impinging on a first group of said photo-receptors of said array of photo-receptors when said object is situated at said first location;
• determining a second centroid of said reflected light beam impinging on a second group of said photo-receptors of said array of photo-receptors when said object is displaced to said second location;
• and
• calculating the displacement of said object between said first and second locations by determining the difference between said first and second centroids.