Abstract: An apparatus positions a flat, rectangular object, such as a photomask, on a stage below the objective of a microscope in the XY plane with provision for rotation in the XY plane to correct for a theta shift. A pair of rails are mounted parallel on the stage and may be adjustably mounted to hold different sizes of flat objects therebetween. The members for locating the object in an exact X and Y location on the rails and for theta shifting the object are preferably mounted on the respective rails and are movable therewith to accommodate various sizes of objects. An inexpensive theta shift is achieved by inexpensive stops and pivot mounted on one rail and a spring biased plunger and an adjustable member on the other rail.

Abstract: Apparatus is provided for attachment to a microscope which alternately positions a filter in alignment with the objective of the microscope and stowed along the side of the body of the microscope. A stationary post is screwed to an accessory fitting associated with the body of the microscope, and a filter holder, which includes a filter-retaining ring and an extending stem, is mounted for rotation from the end of the end of the post. To register the holder stabilized in its aligned and stowed positions, the stem rotates against a face of the post in which a groove is formed, and the stem is biased against the face by a spring so that it catches in the groove in either of the registered positions.

Abstract: A work station for photomask inspection includes a microscope and a movable stage positioned below the objective of the microscope. A rectangular frame of the stage surrounds a viewable area of the stage. Rail means are bolted onto the frame at spaced apart positions corresponding to the width of the photomask that is to be inspected so as to position the photomask therebetween. The rails have end stops that are positionable according to the length of the photomask for positioning the end edges of the photomask therebetween.

Abstract: A switching mechanism has at least two terminals partly positioned within a housing and a reciprocal actuator movable within the housing. A coil spring, under endwise buckling pressure, is mounted between spaced portions of one of the terminals, with movement of the actuator causing the coil spring to pivotally move toward and away from another terminal. A slider is positioned in one end of the coil spring and arranged for contact with the actuator to cause pivotal movement of the coil spring. The actuator and slider have cooperating means for latching the actuator in an operated position.