Abstract: A method and apparatus for determining the transmission capability of a substrate and any damage which may affect said transmission capability comprising directing a focused infrared illumination beam through the substrate and observing the reflected or scattered light to detecting any scratch, fracture, blemish or the like in the substrate surface, or within the substrate itself, by detecting any change in the energy level of the sensed beam or change in reflected scattered light. The illumination beam provides a spot on the substrate surface and, by mapping an entire substrate of said spots adjacent one another and comparing the energy or light level of adjacent spots, any internal or external damage can be determined. A portable battery operable tester with an illumination beam and associated optics and a transmitted beam and associated optics enables such detection of transmission loss.

Abstract: Disclosed are a method and apparatus for addressing a ferroelectric liquid crystal array where pixels are formed at the intersections of columns and rows of electrodes wherein one embodiment of a column write pulse sequence comprises four pulses- one a threshold pulse, two sub-threshold pulses and one zero pulse- all of equal width and within one unit at a time. In another embodiment a column write pulse sequence comprises five pulses- one a threshold pulse, three sub-threshold pulses and one zero pulse, with the threshold and zero pulses having equal widths and the three sub-threshold pulses having equal widths which is twice the width of the threshold pulses. In both embodiments, the same sequence of write pulses are used as row pulses but delayed or advanced to create electric fields of different directions to write a +1 or a -1 pixel depending upon whether or not the row pulse sequence is advanced or delayed.

Abstract: A beam positioning system having two articulated arms with a pentaprism, or equivalent 90 degree prism, and a rotator prism, such as a Pechan prism, appropriately located in the path of a beam from a light source in combination with right angle prisms to maintain the final leg of the beam in orientation with the original orientation of the beam from the light source.