INTERFERENCE METHOD OF TEST OF GEOMETRIC POSITIONING OF LENSES AND INTERFERENCE DEVICE FOR ITS IMPLEMENTATION Russian patent published in 1997 - IPC

FIELD: instrumentation, high-accuracy no-contact determination of distance between optical and geometric axes of lenses and distance between surfaces of lenses. SUBSTANCE: invention solves problem of test of positioning of lenses along geometric axis and of increased accuracy of test. For this purpose radiation source of small coherence length is used. Tested system of lenses is illuminated with the aid of system of two lenses, reference wave is formed by means of beam splitter, first objective and reference reflector placed in series. Interference of waves is consistently obtained during flyback across output of beam splitter and second objective for each tested surface of system of lenses by sequential movement of reference reflector with the use of drive of translational motion with achievement of small optical difference of ray path (corresponding to coherence length of radiation) of reference wave and wave reflected from tested surface. Space coordinates of photoelectric channels realized with the use of multielement photoelectric converter placed across output of second objective are found beforehand relative to specified geometric axis. Multichannel photoelectric conversion of each interference picture is performed. Then collection of values of photoelectric signal for each interference picture is obtained with the use of register, position of collection of values of photoelectric signals is fixed and determined relative to specified geometric axis in memorizing and processing units connected in series to output of register. Translations of reference reflector, changes of optical length of path of reference wave corresponding to various interference pictures are measured by measurement unit. These measurements are used to evaluate positioning of lenses along geometric axis and shift of centers of systems of interference rings is judged by assemblage of shift values of collections of values of photoelectric interference signal obtained in processing unit. EFFECT: increased accuracy of test. 2 cl, 1 dwg