Abstract: An illumination system is provided having one or more light sources, opaque baffles, and mirrors for illuminating indicia on a substrate, such as a semiconductor wafer, for viewing by a camera aligned parallel with or at an angle to the substrate. The light sources include light emitting diodes (LEDs) for illuminating soft marks and broad spectrum incandescent lamps for illuminating hard marks. Dark field and light field illuminators are provided for enhanced reading of light indicia on a dark background and dark indicia on a light background, respectively. A light control unit allows for manual or automated control of light source selection and light intensity. Opposing mirrors extending along the optical paths of the light sources, reflect light emitted from the light sources into the camera field of view, thereby increasing the illumination efficiency and permitting the use of fewer light sources.

Abstract: An illumination system is provided having one or more light sources, opaque baffles, and mirrors for illuminating indicia on a substrate, such as a semiconductor wafer, for viewing by a camera aligned parallel with or at an angle to the substrate. The light sources include light emitting diodes (LEDs) for illuminating soft marks and broad spectrum incandescent lamps for illuminating hard marks. Dark field and light field illuminators are provided for enhanced reading of light indicia on a dark background and dark indicia on a light background, respectively. A light control unit allows for manual or automated control of light source selection and light intensity.

Abstract: Double banks of LED's, opaque baffles, and a camera having a field of view are disclosed for reading laser-etched character strings and other indicia on semiconductor wafers and other substrates. The LED's of the banks may be integrally or separably lensed, and masks may be provided proximate the banks and in the nearfield of the LED's.

Abstract: The minimum edge thickness boundary of an ophthalmic lens is mathematically projected onto a plane containing a scaled image of the spectacle frame while the ground depth of the lens is dynamically varied to obtain circumscription with the image. Optimal tool settings are then determined which will result in a ground prescription lens having minimum overall thickness.