ELECTRO-OPTIC DEVICE FOR MEASURING LINEAR DISPLACEMENTS OF OBJECT Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: device has radiation source, collimator, focusing lens and photodetector, which are mounted along the path of light beam, generator and registrar. Device also has slit and point diaphragms, which are mounted in front of and behind the focusing lens correspondingly along light beam path. Device has beam splitter, which is disposed along the light beam path behind the collimator and intended for separating the second light beam. Reflecting mirror is mounted along the light beam path, the second slit diaphragm, the second focusing lens and the second photodetector, adder. Inputs of the adder are connected to photodetectors. Demodulator and differentiating unit are connected in series. The demodulator is connected with the first photodetector. Differentiating unit is made in form of bandpass filter and lower frequency filter, which are connected in parallel. Correction unit of the device is brought between outputs of differentiating unit and the first input of the registrar The generator is connected to radiation source and to the second input of the demodulator. Errors may be excluded which are related by differentiation absence of changes, which are provided by background illuminations and changes in color rendition factor. EFFECT: improved reliability of operation; improved precision of measurement. 1 dwg