Abstract: A virtual gauging system for use in a lithographic process is described that includes means for gauging a region at a surface of a wafer when the region is located away from an axis of illumination producing wafer surface data, while other portions of the wafer are being illuminated. The system also includes means for converting the wafer surface data into wafer correction data and means for adjusting a separation distance between an exposure lens and the region at the surface of the wafer based on the correction data when the region is located at the axis of illumination. The means for gauging includes at least two wafer surface gauges located on opposite sides of an illumination slot.

Abstract: An optical proximity sensor generates information indicative of a distance to an object in a field and in some embodiments also generates information indicative of a spectral reflectance characteristic of the object. The information indicative of the spectral reflectance characteristic can be used to determine whether the object in the field is a living plant or another object such as soil. Light emitted from the optical sensor for reflection off the object is modulated so that reflected light from the optical sensor can be discriminated from reflected ambient sunlight. The optical sensor is scanned over the field to map objects in the field and/or to determine the location of rows of crop plants. A sensor in accordance with the present invention has many uses in agriculture including spraying, cultivation and vehicle guidance.

Abstract: An optical system and method for data reading in which a light source generates an optical beam directed toward an object to be read and a variable aperture mechanism positioned in the outgoing light path establishes at least two separate focal planes. The variable aperture device may comprise a variable aperture system in which the size of the aperture is selectively varied about a range within the diffractive limit of the light beam. A preferred aperture mechanism is an LCD aperture with one or more aperture regions which are selectively or consecutively activated. The optical system therefore establishes two or more separate focal planes from a single light source resulting in greater depth of field or multiple depths of field.

Abstract: A force sensor detects adhesion between a subject and a substrate through an adhesive. The sensor is embedded in the adhesive and is formed by two members which are displaceable relative to each other. A readout scheme detects displacement of the two members due to a force and reaction forces acting upon the sensor through the adhesive. Fiber optics may be employed in the readout scheme to provide an indication of displacement of the two members and thereby adhesion of the subject to the substrate.