Magneto-Optical Actuator for Displacement Measurement

摘要

In this work, a simple device for controlling the desired relative position between the fixed optosensor set, and the mobile tip is presented. The opto-sensor houses both, emitter and detector, in a single package; this feature facilitates a simpler mechanical design with respect to the cases where emitter and detector are separated components. This sensor arrangement contains an infrared LED emitter and a matched IC photodetector. A bifurcated lens-allocated into the own package above these active elements-focuses a small spot in front of the package. The obtained photocurrent depends on the magnitude of the reflected signal, and hence, the distance to the reflector. Therefore, the sensor response depends on the relative position between the opto-sensor and the reflectance surface. By an adequate and simple electronics system, a feedback current is applied to the magnetic coil based actuator, which compensates the measured displacement, returning the actuator tip to the desired position.