Abstract: A scanning apparatus periodically sweeps a beam of light across a printed circuit board in a plurality of sweep paths. An associated detector is responsive to radiation from the printed circuit board for producing first and second signals indicating whether a conductor portion or substrate portion of the board is being swept. An associated automatic level control is responsive to the first and second signals for providing level adjusted output signals. The levels of the adjusted output signals are substantially the same for all printed circuit boards swept in the scanning apparatus.

Abstract: A scanning apparatus which periodically sweeps a beam of light across a printed circuit board along a plurality of sweep paths, includes a detector responsive to radiation from the printed circuit board as the board is swept by the beam of light. The detector is also responsive to first and second adjustment signals indicating whether a conductor portion or substrate portion of the board is being swept. An automatic level control is responsive to the first and second signals for providing level adjusted output signals via an adjustor coupled to the detector. The levels of the output signals form a ratio R substantially the same for all boards swept in the scanning apparatus.

Abstract: Apparatus is provided for imposing measurable wear on the surface of a magnetic recording disk and for determining the relationship of read/write characteristics due to such wear. A dynamic air bearing separates the interface between the disk surface and a slider head. The imposed wear changes the relationship between the head and disk and the changes provide measurable data for experimental evaluation of read/write slider flying dynamics.

Abstract: The invention pertains to an optical scanning system which is capable of reading the UPC (Universal Product Code) symbol, which is printed out of tolerance because the black bars are too wide and the white spaces are too narrow. The system provides an arrangement for selecting any one of three (3) modes of operation, wherein two (2) of the modes provide white space enhancement (a narrowing of the signals representative of the width of the black bars and a widening of the signals representative of the white spaces) and one (1) mode provides no enhancement at all.

Abstract: The invention pertains to an optical scanning technique which is capable of reading and accepting a wide range of out-of-tolerance symbols. The technique provides that if a successful scan occurs, the signal circuits maintain a status that indicates a true signal is being processed. However, if an unsuccessful scan takes place the signal circuits introduce a distortion therein in order that the symbol may be read successfully.