Dark Field Illuminator
Original Publication Date: 1978-Jun-01
Included in the Prior Art Database: 2005-Feb-21
Light diverging from light source 1 is collimated by condenser 2 and transformed by glass cone 3 (axicon) into a conical hollow toroid, the walls of which consist of parallel rays. The light leaving the axicon is transformed by lens 4 and mirror 5 into an annular light bundle with focus plane 6, which impinges on dark-field condenser 7 to provide dark-field illumination in target plane 8.