초록 ▼

An actuator having an optical position sensor is disclosed. The sensor remotely provides via a single optic fiber light having two spectral frequencies of about equal intensities to two inversely acting linear optical attenuators that attenuate light in response to the intensity of a magnetic field

An actuator having an optical position sensor is disclosed. The sensor remotely provides via a single optic fiber light having two spectral frequencies of about equal intensities to two inversely acting linear optical attenuators that attenuate light in response to the intensity of a magnetic field varied in relation to the movement of the actuator. The attenuated light from each attenuator is filtered producing two attenuated light signals of the two frequencies that are combined in another single optic fiber and then processed into voltages indicative of their intensities. The position of a moving object attached to the attenuators is derived from the difference of the two signals relative to their combined value, minimizing errors associated with obstructions the optical couplings. The attenuators may be orthagonal strips that slide in unison in slots in an elongated rod containing light transmitters and receivers. Light transmittance of the strips varies along their length. The strips are joined as a cartridge that slides within the rod.

대표청구항 ▼

An actuator comprising sensor means for indicating the position of an object constrained to move in one dimension between first and second positions, characterized by: light source means for illuminating a first point and a second point with light comprising a first frequency and a second frequency

An actuator comprising sensor means for indicating the position of an object constrained to move in one dimension between first and second positions, characterized by: light source means for illuminating a first point and a second point with light comprising a first frequency and a second frequency different from the first frequency, the first and second frequencies having about equal intensity; first attenuation means for illuminating a third point with light originating from the first point, the intensity of the illumination at the third point linearly decreasing with a change of position of the object in a first direction; second attenuation means for illuminating a fourth point with light originating from the second point, the intensity of the illumination at the fourth point linearly decreasing with a change of position of the object in a second direction opposite the first direction; receiver means for providing a first signal indicative of the intensity of light of the first frequency illuminating the third point and a second signal indicative of the intensity of light of the second frequency illuminating the fourth point; processing means for providing a third signal indicative of the position of the object as a function of the first and second signal; the first and second attenuator means comprising means responsive to a varying magnetic field to vary light attenuation; and means individual to the first and second attenuators for providing an inversely varying magnetic field to an actuator in response to movement of the object.