Patent ID: 6059421
Filing Date: 2000-05-09
Classification: G01N,Y10S

Abstract:
A compact diffuse illumination device for evenly illuminating a desired portion of an object when observed along an observing axis extending through an object observing location, said compact diffuse illumination device comprising:a first diffuser surface, for supplying diffused light, defining a first opening through which the observing axis passes, said diffuser surface being arranged to supply a primary diffused light, from a primary light source, to provide said even illumination of the desired portion of the object, when placed at the observing location and viewed along said observing axis, except for a portion of the object effected by the opening;a secondary light source for supplying secondary diffused light to illuminate a desire portion of the object; anda primary beam splitter selected from the group consisting of a curved beam splitter and a planar beam splitter for supplying said secondary diffused light along the observing axis to evenly illuminate each portion of the object effected by the opening to produce, when a primary diffused light illuminates said surface, said illumination of the object when viewed along the observing axis;wherein said first opening defines a clear aperture of the illumination device and the height of the illumination source is equal to about three times said clear aperture largest dimension or less.