METHOD FOR MARKING, CAPTURING AND DECODING MACHINE-READABLE MATRIX SYMBOLS USING ULTRASOUND IMAGING TECHNIQUES

The invention is a method and apparatus for the application of machine readable matrix marking symbols, and especially two-dimensional matrix symbols, to a "host" substrate, optionally covering the symbols with protective layers, then using an ultrasound imaging apparatus to capture echo signals associated with the matrix symbols, then feeding the resultant information to a matrix symbol decoder to yield human-readable and video monitor displayable information.