Abstract: A monoaxial coarse-fine adjusting apparatus for optical instruments has a pair of friction wheels whose peripheries are in engagement with the fine adjusting shaft. The axles to which the friction wheels are mounted are received in slots formed in the coarse shaft. The coarse adjusting knob has a surface which the friction wheel axles bear against. A pair of springs are provided which accommodate for torsion and backlash. Rotation of the coarse knob directly rotates the coarse shaft. Rotation of the fine knob rotates the friction wheels in a planetary fashion. The friction wheel axles which are received in the slots in the coarse shaft, drive the coarse shaft an amount which is proportional to the rotation of the fine knob.

Abstract: A compact portable microscope includes an optical tube assembly which is resiliently mounted therein. Adjusting members bear against the optical tube to shift the position of the objective relative to the stage. The image of the specimen being examined may, therefore, be selectively positioned within the field of view of the microscope. The optical tube assembly is also movable axially within the housing for focussing.

Abstract: A multi-objective optical instrument, such as a microscope, has a photocell disposed in the optical path so as to effectively detect the intensity of light being transmitted by an illuminator to a receptor plane, such as defined by an operator's eyes. The light detected by the photocell is compared against a preset level of light. The intensity of the illumination would be adjusted automatically to a minimum level when the carrier is rotated and to a preselected level when an objective is in place for viewing. An electrical switch is cooperatively mounted to the rotatable objective carrier and detects rotation of the carrier to control the flow of current to the illuminator.

Abstract: A portable microscope for inspecting fiber optic cables has an illumination system including a selectively positionable light occluder which permits end examination of a cable when in a first position and examination of the optical transmission of the cable when in a second position.

Abstract: A specimen mount for a microscope holds a fiber optic cable so that the end of the cable may be examined. The mount is rotatable to angularly displace the cable end being examined.