Carl-zeiss-stiftung

Adalbert Hanssen

Albrecht Hof

Jurgen Schwarz

A spectacle lens has a spherical or rotationally symmetrical, aspheric front side and a back side prescription surface. All individual requirements of the prescription for spectacles, consisting of spherical, astigmatic and prismatic power and their distribution on the x and y axes on the spectacle lens surface, are fulfilled by the prescription surface. The back surface of the spectacle lens is a multifocal surface without point symmetry and/or axial symmetry. A process that produces spectacle lenses with multifocal power starts with variants of a first or of a few spectacle lens(es) that originate according to prior art design considerations. The semi-finished lenses have spherical or aspheric, rotationally symmetrical, convex front surfaces, with about 10 different radii. The whole matching of individual required dioptric power takes place on a free-form back surface of the spectacle lens facing the eye of the wearer. The shape of this back surface follows from an individual optimization calculation using the design of the predefined starting surface as the start of the optimization.

Spectacle lens with spherical front side and multifocal back side and

In a process and apparatus for measuring object topographies by means of projected fringe patterns, to enlarge the region of certainty, different periodicities are evaluated. Calibration of the measurement apparatus is carried out in at least two parallel planes, situated in the forward and in the rearward regions of the measurement volume. Corrected phase values are first calculated from the phase measurement values of the measurement object. By combination of the phase measurement values relating to the pattern of long periodicity and of the pattern of short periodicity, the fringe order of the phase values relating to short periodicity is calculated. By interpolation of the correction values between the two planes in which the reference measurements were carried out, the measurement process and a corresponding measurment apparatus provide highly accurate measurement values, with simultaneously reduced requirements on the accuracy of mechanical and/or optical adjustment.

Process and apparatus for the measurement of object topographies by

A single projector is used to project a grating pattern on the surface of the object being measured, and the grating pattern is recorded simultaneously by two cameras from two different directions relative to the direction of projection. Both cameras record images of the same object areas. The fringe phases of the image patterns recorded by each of the two cameras are computed separately; and the object coordinates, which are computed from the combination of the computed fringe phases of both cameras, are unambiguous within a large measured range.

Method and apparatus for three-dimensional optical measurement of object

The invention is directed to an arrangement for controlling a movement and includes an arrangement wherein the an actuating manipulator provides an output signal proportional to displacement. The arrangement includes a circuit which multiplies the output signal by a factor F which is dependent upon the speed of the actuation. In this way, the manipulator is suitable not only for controlling very fine sensitive positioning; but it also allows a fast displacement of the driven part over large distances. With manipulators for controlling movements in more than one dimension, output signals are multiplied by the same factor for all coordinates in order that directional accuracy of the movement is guaranteed at all speeds. A track ball can be utilized as a manipulator, for example. The arrangement of the invention is applicable for manually positioning microscope tables, coordinate measuring machines and ophthalmic apparatus.

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Konigsbronn, Germany

Adalbert Hanssen