ESTIMATION OF CLEARANCES IN THE DESIGN AND ADJUSTMENT OF BARREL TYPE LENS SYSTEMS

摘要

Estimation of probable clearances in the fit of the installed lenses and the impact from mounting and adjustment of units on system alignment and the resulting imaging quality has been considered. The characters of dispersion fields and acceptable deviations in mating dimensions of parts and their allowance have been analyzed for the estimation of probable clearances. Very commonly existing deviations in the clearances have a considerable systematic component due to systematic components of errors in the mated dimensions of parts. It has been shown that the assembly of lens based optical systems in horizontal position of its body allows vast reduction of the impact given by clearances on the accuracy of the alignment of the lens parts as compared to assembly in vertical position of its body, as in the this case the lens misalignment is due to errors in the diameters of lens components. For the adjustment of the quality of the image generated by the optical system it is necessary to take into account both the impact from misalignment of lens components on edge and central aberrations of the image field.