METHOD AND DEVICE FOR AUTOMATICALLY FOCUSING OPTICAL EQUIPMENT USING SCANNING LATTICE

摘要

The instrument has a grid (20), which acts as a spatial frequency filter and is movably arranged in an intermediate image plane of the beam path of the instrument, and to which there is assigned a photoelectric receiver system (23, 24) which scans light fluxes leaving the grid and converts them into corresponding electric signals which are used as control signals for focusing. The grid (20) is short relative to the extent of the intermediate image (19), and the drive means (21) for the movement of the grid are dimensioned such that the grid executes a movement extending over a plurality of grid constants. IMAGE