APPLICATION OF FOCUSED LASER BEAM IN LINEAR ENCODER

M. Dobosz

Abstract

The idea of high resolution (0,01 µm) displacement encoder with laser diode light beam focused on the scale surface is presented. Due to application of the focused laser beam the acceptable tilts of the encoder head relative to the grating in the prototype device reach about of 0,5 arc degree in all directions and the tolerance of the distance between head and the grating is equal to about 0.1 mm. A new simple reference point detection method that use a scale grating edge as an reference point has been proposed. This technique allows significant reduction of nonlinearity errors of the measuring system. Nonlinearity of the prototype device does not exceed 0,1 µm in 48 mm measuring range.

Keywords

displacement measurement; interferometer; laser diode; diffraction grating; focused light

Download

IMEKO-WC-2000-TC14-P364.pdf

DOI

-

IMEKO TC

TC14 - Measurement of Geometrical Quantities

Back to the proceedings