LINEAR MOVEMENT DETECTOR Russian patent published in 1997 - IPC

FIELD: instruments. SUBSTANCE: device has light source, serial optical circuit of transparent diffraction pattern, moving reflecting diffraction pattern, which is associated with object, four lenses and four photodetectors. Transparent diffraction pattern has two groups of strokes,. Lenses are located in pairs behind each group. Angle θ between groups of strokes is q = d/D, where d is constant of transparent pattern, D is distance between optical axes of lenses which are spread along stroke. Corresponding photodetectors which are spread along stroke are connected opposing, because photodetectors are spread in direction which is perpendicular to strokes. Phase shift between signals from photodetectors is equal to right angle. EFFECT: increased functional capabilities. 3 dwg