Vickers, Inc.

Francis H Smith

Richard W Gale

In a measuring microscope for measuring the distance between line elements of an optical image, means are provided for forming from an image-carrying beam, carrying the optical image, further image beams in which light of respective complementary regions of the image-carrying beam is suppressed, to form respective distinct non-overlapping but adjacent image portions for viewing. Means are provided for then carrying out calibrated displacement of the adjacent image portions. Thus, a line element in one image portion can be brought into alignment with a line element of an adjacent image portion. The degree of calibrated adjustment required for this gives a measure of the distance between the two line elements on the object which is imaged. The microscope may be constituted so that means involved in the suppression of complementary regions of the image-carrying beam are readily removable so that overlapping images can be provided for viewing.

Measuring microscope

An optical viewing apparatus and method is disclosed having improved focusing, in which two beams of light, which are mutually inclined at a fixed angle, are converged in the vicinity of a reflective viewed surface, and the relative distance between the apparatus and the surface is adjusted until the beams coincide at the surface.

Focusing of optical viewing apparatus

A diffractometer comprises means for illuminating a specimen plane and a lens for converging rays diffracted from the specimen plane. In order that existing optical apparatus may readily be adapted for use as a diffractometer, the illuminating means (12a, 12b, 13, 14) is arranged to illuminate the specimen plane (0-0') at an acute angle, and a positive lens (15) having its principal axis normal to the specimen plane (0-0') is arranged to converge rays diffracted normally from the specimen plane. The apparatus is particularly susceptible to compact construction by arranging, in successive order from the specimen plane (0-0'), a field stop (17), the positive lens (15), an aperture stop (16) and a photo-detector (19), which parts advantageously can form a modular assembly. The invention is particularly applicable to converting microscopes for use as diffractometers, which then are suitable for use in monitoring respirable air-born fibers.

Diffractometer

A diffractometer comprises means for illuminating a specimen plane and a lens for converging rays diffracted from the specimen plane. In order that existing optical apparatus may readily be adapted for use as a diffractometer, the illuminating means (12a, 12b, 13, 14) is arranged to illuminate the specimen plane (0--O') at an acute angle, and a positive lens (15) having its principal axis normal to the specimen plane (0-0') is arranged to converge rays diffracted normally from the specimen plane. The invention is particularly applicable to converting microscopes for use as diffractometers, which then are suitable for use in monitoring respirable air-borne fibers.

An optical image splitting apparatus is provided in which an image splitting surface capable of splitting an incident beam into first and second beams by transmission and reflection respectively is so arranged in relation to an uneven number of reflection surfaces that the two beams are reflected through respective paths in the apparatus and leave the apparatus in the same general direction. One of the reflection surfaces is common to the two paths and is deflectable to deflect the two paths in opposite angular directions in order to adjust the distance between the centers of the images formed from the two beams. The apparatus may include a device for blanking out one or other of the beams.

Optical sizing instrument

An interferometric apparatus comprises an optical assembly which simultaneously directs two mutually coherent light pencils at different respective angles of incidence towards a point on a surface and receives the reflected light pencils therefrom. The assembly includes optical means bringing the reflected pencils at least partially into coincidence so that they can interfere optically in a manner varying with variation in the distance of points on the surface from a reference plane. The assembly may be combined with a microscope to form a 'pupil-shearing micro-interferometer' for investigating surface topography.

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York, United Kingdom

Francis H Smith