Abstract: A shock and vibration isolation system having a plurality of isolators supporting a utilization device is disclosed. Each isolator has two gas driven pistons, pivotally mounted in a frame and is connected to an accumulator/controller that supplies controlled amounts of pressurized gas. A sensor in each isolator senses the position of the utilization device with respect to a base sitting on the ground, and the accumulator/controller adds gas to or exhausts gas from the pistons to counteract changes in position detected by the sensor. An electronic control circuit is connected between the sensor and the accumulator/controller to supply a properly compensated signal from the sensor to control the accumulator/controller.

Abstract: A projection lens is mounted between a movable stage and a stationary holder to project an image of a reticle held by the holder onto a semiconductive wafer held by a chuck mounted on the stage. The stage is movable along orthogonal X and Y axes in a horizontal plane to align different regions of the semiconductive wafer with the projected image of the reticle. First and second movable plane mirrors fixedly mounted on the stage for movement therewith are symmetrically disposed relative to the Y axis in first and second vertical planes intersecting one another at the Y axis. Similarly, first and second stationary plane mirrors fixedly mounted on a housing of the projection lens are disposed parallel to the first and second movable mirrors, respectively.