Contact problems between optical lenses and shrink fitter for a new type of laser microscope with a wide field of view

Abstract

We have studied contact stiffness between randomly rough surfaces. This research led to the development of a shrink fitter consisting of a new ring-shaped machine element to join mechanical components with different coefficients of thermal expansion, such as a ceramic shaft and a metal cylinder. As one application of the shrink fitter, several optical lenses were shrink-fitted in a lens-barrel. Such a scanning lens, assembled using the shrink fitter, can focus laser light well over a wide scanning width because the optical axes of the several lenses in the lens-barrel compliment each other well regardless of changes in room temperature. Thus, a laser microscope with such a scanning lens can observe object surfaces over a relatively wide area. However, contact pressures between the shrink fitter and the optical lenses will change the curvature of the lenses resulting in deterioration of the scanning properties of the scanning lens. Therefore, it is very important to calculate the contact pressures acting on optical lenses to examine the scanning properties of the scanning lens. In this study, we have developed a new type of laser microscope with a field of view of 10 × 8 mm. The pixel number in the laser scanning direction of 10 mm was 20,000 and 16,000 in the perpendicular direction of 8 mm. Thus, one field of view of this laser microscope had 320,000,000 pixels. The observation results of some surfaces by this laser microscope are reported.