Abstract: An absolute position encoder for identifying which of a plurality of loci a moveable member occupies comprises a plurality of data tracks in which binary data is encoded to form a series of n-bit words, each of the plurality of loci being associated with one of the n-bit words. A plurality of the n-bit words is required to uniquely determine which of the loci the moveable member occupies. The absolute position encoder does not use a clock track to resolve the problem of asynchronous bit transitions.

Abstract: An absolute position encoder for identifying which of a plurality of loci a moveable member occupies comprises a plurality of data tracks in which binary data is encoded to form a series of n-bit words, each of the plurality of loci being associated with one of the n-bit words. A plurality of the n-bit words is required to uniquely determine which of the loci the moveable member occupies. The absolute position encoder does not use a clock track to resolve the problem of asynchronous bit transitions.

Abstract: A system for measuring torque comprises a pair of drive shafts connected by a torsion bar, a wheel affixed to each of the drive shafts and having at least one slot cut through it, a light source positioned on the side of one of the wheels opposite the other, and a light detection device on the opposite side of the other wheel positioned to detect light from the light source which passes through the slots in both wheels. The slots are positioned in the wheels such that the light that can pass from the light source, through both wheels, and to the detector changes as the angular position of the wheels changes relative. The light detection device observes the changes in this pattern of light to produce a signal indicative of the torque on the drive shaft that is producing the observed angular displacement of the wheels.

Abstract: A system for measuring torque comprises a pair of drive shafts connected by a torsion bar, a wheel affixed to each of the drive shafts and having at least one slot cut through it, a light source positioned on the side of one of the wheels opposite the other, and a light detection device on the opposite side of the other wheel positioned to detect light from the light source which passes through the slots in both wheels. The slots are positioned in the wheels such that the light that can pass from the light source, through both wheels, and to the detector changes as the angular position of the wheels changes relative. The light detection device observes the changes in this pattern of light to produce a signal indicative of the torque on the drive shaft that is producing the observed angular displacement of the wheels.