Condenser Alignment In Telecentric Systems With Partially Coherent Illumination
Original Publication Date: 1979-Oct-01
Included in the Prior Art Database: 2005-Feb-20
A telecentric system with a 1:1 magnification consists of lenses L1, L2 with aperture A positioned in the common focal plane. When subjected to partially coherent illumination, the aperture is not completely filled by the condenser-generated image LS of the light source. If the center of this image is shifted out of the optical axis, for example, by tilting the condenser (on the left of object plane 0, not shown), the telecentricity of the projection system is distorted, and the size of the images in image plane 1 is no longer insensitive to defocusing (displacements of object in object plane 0).