International Business Machines Corporation

Discovision Associates

Bernhard Solf

Michael H Kallmeyer

Claus Scheuing

Hans Rosch

Geunter Makosch

A deflection arrangement is described which comprises several piezocrystal elements which are separately driven by a positive or a negative voltage. In this configuration, there is no elastic hysteresis. The arrangement is particularly suitable for automatic focusing systems.

Binary piezoelectric drive for lens focusing system

Two radiation components differing from each other with regard to their state of polarization or their wavelength are directed onto closely adjacent points of the object to be measured. The reflected components are recombined and are fed to a polarization- or wavelength-dependent phase shifter periodically shifting the phase positions of the two components by .lambda./2 against each other. A phase shift of one of the components caused by the object to be measured is fully compensated for by periodically shifting the phase position of the other component at particular points in time, which can be determined, for example, by means of a connected analyzer and a photodetector. The values of the control voltage effecting the periodical phase shift in the phase shifter are measured at those points in time at which the phase difference between the two components equals zero. These values are proportional to the difference in height between the points of incidence of the two radiation components on the object surface or the slope of the object surface.

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Sindelfingen, Germany

Bernhard Solf