Abstract: Methods, systems, and apparatus for imaging a substrate through the use of retro-reflective optics and detecting any defects and patterns therein. Through the use of optical imaging, optical focusing is adjusted to capture optical effects of interest in the substrate with enhanced size, precision, clarity and image quality. Imaging data obtained from these images may then be analyzed. Both bright field image data and dark field image data are captured and analyzed to provide accurate and reliable imaging results. The invention is suitable for use in on-line, real-time detection of visual defects and pattern recognition or off-line for non-production use.

Abstract: A centrifugal pump comprising a cylindrical outer housing having a fluid feed conduit concentrically arranged therein with the outer wall portions thereof spaced from the inner walls of this outer housing to provide a fluid discharge outlet therebetween and a stator secured to one end of said housing having fluid discharge channels open to said fluid discharge outlet and a rotor casing encompassing said stator rotatable relative thereto wherein air bubbles in the fluid feed are sheared in a deaerating chamber adjacent said stator and vent means provided for discharging air from the rotor casing.