Patent ID: 6449088
Filing Date: 2002-09-10
Classification: G02B

Abstract:
An optical imaging system illumination apparatus for providing a variable dark-field image wherein features of an object appear to be light and a background appears to be dark and whereby the light from said object of the image passes freely through an optical discriminator and into a pupil and light from a source, said source appearing in a field-of-view of imaging optics, is blocked at the optical discriminator and does not pass into the pupil of the imaging optics; the apparatus comprising:a) an illumination source, which produces polarized light that propagates as a beam substantially along an optic axis; b) the optical axis, which defines an axis of symmetry for cylindrically symmetric optics which include special cases of spherically symmetric optics, whereby a beam of light from said light source propagates away from a light source along the axis; c) an object volume, which is symmetric about said optical axis having peripheries defined by extent of the beam of light and the limits of the field of view of; d) imaging optics, which produce an image in an image volume of an object in said object volume which has a light field emanating therefrom; e) a pupil aperture, symmetric about the optic axis between the object volume and the imaging optics; f) the optical discriminator, symmetric about the optic axis between the object volume and the imaging optics; and g) a detector, in the image volume of said imaging optics.