device for monitoring moiremustern of test surfaces, using the moireverfahrens with phasenshiften

摘要

PCT No. PCT/DE89/00788 Sec. 371 Date Jun. 21, 1991 Sec. 102(e) Date Jun. 21, 1991 PCT Filed Dec. 22, 1989 PCT Pub. No. WO90/07691 PCT Pub. Date Jul. 12, 1990.The object of the invention is a process for observing moiré patterns of surfaces to be tested, wherein the object gratings to be observed are pictured onto auxiliary gratings and the moiré patterns generated thereby are detected, stored and/or processed by computer, wherein for each observation at least phase-shifted moiré patterns are respectively evaluated. Furthermore, the invention relates to a device for observing moiré patterns of the surfaces to be tested by applying the moiré method using phase shifting. For an observation of the phase-shifted moiré patterns associated with the object grating are simultaneously generated, pictured and detected by superposition of the object grating image with auxiliary gratings which are disposed in a phase-shifted manner.