Radial optical encoder apparatus for shaft angle measurement

Claim 2

A radial optical encoder apparatus for shaft angle measurement comprising in combination: a shaft capable of rotation about its central axis, said shaft having a ring radially disposed thereon, said ring having a plurality of faceted surfaces disposed on it's outer surface parallel to said shaft central axis, said faceted surfaces being positioned in a predetermined pattern, a first optical encoder means positioned substantially perpendicular to said shaft, said first optical encoder means detecting angular rotation in said shaft position, said first optical encoder means converts said angular rotation into a pair of electrical output signals, said pair of electrical output signals being representative of said shaft position, a second optical encoder means positioned diametrically opposite said first optical encoder means, said second optical encoder means cooperating with said ring to provide a pair of auxiliary signals, and, an electronic processing means receiving said pair of electrical output signals and said pair of auxiliary signals, said electronic processing means decoding both pairs of input signals to provide three output signals.

Claim 3

A radial optical encoder apparatus as described in claim 1 wherein said first optical encoder means comprises in combination: a cylindrical housing having a first and second opening, said cylindrical housing being hollow, said cylindrical housing having a central axis which is perpendicular to said central axis of said shaft, a first and second light source mounted in said first opening of said cylindrical housing, said first and second light source emitting respectively a first and second light beam, a reticle means mounted in said first opening in front of said first and second light source, sad reticle means being centered on said central axis of said cylindrical housing, said reticle means being a glass blank with an opaque metalization on its surface, said reticle means having a plurality of slits disposed therein, said plurality of slits being arranged in a predetermined pattern, a plurality of lenses positioned within said cylindrical housing near said second opening, said plurality of lenses directing said first and second light beams to a focal point at a predetermined distance from said second opening, and, a first and second detector means receiving said first and second light beams, said first and second detector means respectively converting said first and second light beams to a pair of electrical output signals.

Claim 4

A radial output encoder apparatus as described in claim 1 wherein said plurality of facets comprise a plurality of flat mirrors.

Claim 5

A radial optical encoder apparatus as described in claim 2 wherein said first and second light source and said first and second detector means respectively are at a predetermined angle with respect to each other.

Claim 6

A radial optical encoder apparatus as described in claim 1 wherein said first optical encoder means resolves linear shaft translations of 0.100 inch along the shaft axis.

Claim 7

A radial optical encoder apparatus as described in claim 1 wherein said first optical encoder means resolves radial linear translations of 0.05 inch in each of two orthogonal axis.

Claim 8

A radial optical encoder apparatus as described in claim 1 wherein said first optical encoder means provides fine shaft angle resolution.

Claim 9

A radial optical encoder apparatus as described in claim 1 wherein said second optical encoder means provides coarse shaft angle resolution.