Bright field-dark field illumination system

Claim 2

A vertical bright-field and dark-field microscope illuminator having a light source and a microscope objective with a shoulder aligned on an optical axis, which comprises, a first lens system for collecting light from the source, a second lens system for receiving light from said first lens system and focusing an image of the source, a partially transmissive mirror selectively positionable on the optical axis to deflect light from said second lens system toward the objective for bright-field microscopy, an annular reflector located on the optical axis near the objective, an alternate optical axis used when said mirror is positioned off the optical axis, a relay system on said alternate optical axis to focus light presented to said annular reflector near the objective shoulder for dark-field microscopy.

Claim 3

The vertical bright-field and dark-field microscope illuminator of claim 1 wherein the relay system has a zone of collimated light to maintain a constant relationship between the image and the objective shoulder during dark-field microscopy.

Claim 4

The vertical bright-field and dark-field microscope illuminator of claim 1 wherein said first lens system includes a biconvex positive singlet I and a biconvex singlet II with an axially-symmetrical, aspheric second surface, said second lens system includes a biconvex positive singlet III and a biconvex positive doublet IV and said relay system includes a concave-plano negative singlet V, a mirror M 2 , biconvex positive singlet VI and a Mirror M 3 .

Claim 5

The vertical bright-field and dark-field microscope illuminator of claim 3 having the parameters set forth below wherein successive lens radii are designated R 1 -R 15 , where a minus sign indicates a radius of center of curvature lying opposite the source filament side of its vertex, axial thicknesses of successive lens elements are designated T 1 -T 7 , successive axial spaces are designated S 1 -S 15 , radii, thickness and spacings all being in millimeters, refractive indicies and Abbe numbers of the successive lens elements are designated ND 1 -ND 7 and ν 1 -ν 7 , respectively; __________________________________________________________________________ BRIGHT FIELD Index of Abbe Radius Thickness Spacing Refraction No. Lens (R) (T) (S) (ND) (ν) __________________________________________________________________________ S.sub.1 = 8.00 R.sub.1 = 89.448 I T.sub.1 = 4.5 ND.sub.1 = 1.523 ν.sub.1 = 58.6 R.sub.2 = -9.269 S.sub.2 = 0.10 R.sub.3 = 40.643 II T.sub.2 = 5.0 ND.sub.2 = 1.523 ν.sub.2 = 58.6 R.sub.4 = -16.726* S.sub.3 = 65.06 R.sub.5 = 30.280 III T.sub.3 = 4.0 ND.sub.3 = 1.523 ν.sub.3 = 58.6 R.sub.6 = -30.280 S.sub.4 = 4.00 S.sub.5 = 54.00 S.sub.6 = 44.01 R.sub. 7 = 52.780 IV T.sub.4 = 2.5 ND.sub.4 = 1.785 ν.sub.4 = 25.7 R.sub.8 = 22.736 T.sub.5 = 7.0 ND.sub.5 = 1.548 ν.sub.5 = 45.8 R.sub.9 = -33.268 S.sub.7 = 12.00 S.sub.8 = 61.00 to 75.50 S.sub.14 = 18.00 S.sub.15 = 1.64 __________________________________________________________________________ DARK FIELD Index of Abbe Radius Thickness Spacing Refraction No. Lens (R) (T) (S) (ND) (ν) __________________________________________________________________________ S.sub.1 = 8.00 R.sub.1 = 89.448 I T.sub.1 = 4.5 ND.sub.1 = 1.523 ν.sub.1 = 58.6 R.sub.2 = -9.269 S.sub.2 = 0.10 R.sub.3 = 40.643 II T.sub.3 = 5.0 ND.sub.2 = 1.523 ν.sub.2 = 58.6 R.sub.4 = -16.726* S.sub.3 = 65.06 R.sub.6 = 30.280 III T.sub.3 = 4.0 ND.sub.3 = 1.523 ν.sub.3 = 58.6 R.sub.6 = -30.280 S.sub.4 = 4.00 S.sub.5 = 54.00 S.sub.6 = 44.01 R.sub.7 = 52.780 IV T.sub.4 = 2.50 ND.sub.4 = 1.784 ν.sub.4 = 25.7 R.sub.8 = 22.736 T.sub.5 = 7.0 ND.sub.5 = 1.548 ν.sub.5 = 45.8 R.sub.9 = -33.268 S.sub.7 = 12.00 S.sub.9 = 41.60 R.sub.10 = -19.580 V T.sub.6 = 2.50 ND.sub.6 = 1.523 ν.sub.5 = 58.6 R.sub.11 = ∞ S.sub.10 = 9.90 S.sub.11 = 40.88 to 55.38 R.sub.12 = 115.723 T.sub.7 = 4.5 ND.sub.7 = 1.648 ν.sub.7 = 33.9 R.sub.13 = 115.723 S.sub.12 = 15.62 S.sub.13 = 51.50 S.sub.14 = 18.00 S.sub.15 = 1.64 __________________________________________________________________________ *aspheric surface