496 Каталог MAHR 2014 Измерительные инструменты и приборы для линейно-угловых измерений Стр.15-35

Каталог MAHR 2014 Измерительные инструменты и приборы Стр. 15-35 0496 ENG Lab2u

MarSurf Surface Measuring Instruments and Systems M 15-35 Mahr MarSurf LD 130 Aspheric LD 260 Aspheric High-precision 2D 3D Measuring Station for Measurement and Evaluation of Optical Components Desription An increasingly more compact and favorable system design is demanded on optical systems such as zoom lenses optics for DVD drives and lenses in the cameras of mobile phones for example. For this purpose in addition to classic spherical lense shapes (sphere-shaped) the optics industry is increasingly producing aspherical (not sphere-shaped) lenses. The evaluation program serves to analyze measurements on spherical surfaces with Mahr contour measuring units. Measured profiles are imported the nominal form of the aspheres are defined and the residual error is determined compared to the nominal form. The data of the determined differential profile is made available in a machine-readable format for readjustment of the processing machine (closed loop). In comparison to the laser interferometer the tactile measuring technology also allows 2D and 3D measurement of optically rough surfaces so that testing and correction is possible already early on in the production process (grinding). Measuring Principle For a 3D measurement two parallel linear profiles offset by 90 are measured across the zenith of the asphere. The several concentric circular profiles are gathered by turning the C-axis. These measured points are used to create the topography. As the probe arms can be positioned automatically i.e. lifted-off and contact even discontinuous surfaces e.g. with a hole in the center can be measured. The use of the machine in a vibration-damped enclosure keeps ambient influences such as vibrations and impurities away from the measuring object. Asphere Definition An aspherical surface is a refracting or reflecting surface which devi ates from a spherical surface. The mathematical description of the sagitta Z (dependance of the vertical height to the horizontal coordinates) of aspherical surfaces based on a conical section is given in the following equation z(h) l +. l (l + k + X . h Ro Radius of curvature h Radius of the area of application of the asphere k Conical constant Ai Aspheric coefficients 0 0