DEVICE TESTING FOCAL DISTANCES OF OPTICAL SYSTEMS Russian patent published in 2004 - IPC

FIELD: instrumentation engineering. SUBSTANCE: device incorporates collimator, test-object in the form of group of parallel lines placed in focal plane of lens of collimator and microscope including projection lens and counting unit. Counting unit has two mirrors installed at angle with optical axis of projection lens, two videocameras, each being optically coupled to corresponding mirror, commutator, former of test marks and video control unit. One videocamera is installed for adjustment movements in direction perpendicular to optical axis of projection lens and crossing line of mirrors. First and second inputs of commutator are connected to proper videocamera and first and second inputs of former of marks are connected to corresponding outputs of commutator and its output is coupled to video control unit. EFFECT: increased precision and shortened measurement time. 5 dwg