Abstract: A electro-optical memory includes a substrate on which is printed (or otherwise inscribed) a complex symbol or "label" or "bar code" of a high density two-dimensional symbology. The bar code contains component symbols or "codewords" which are placed in row and column formation, with a variable number of codewords per row, and a variable number of rows. The symbology utilizes implicit bar code encoding scheme for implicit encoding the number of rows and the number of columns of codewords, as well as a predetermined amount of error correction. The symbology is capable of supporting a fixed number of bar code variants, with each variant having a predetermined number of rows and columns of codewords, and a predetermined error correction capability. For some codewords the implicit encoding scheme is combined with a gray coding scheme to reduce the inter-row codeword crosstalk.

Abstract: The use of low molecular-weight or polymeric organic compounds which are present in the columnar-helical phase and have liquid-crystalline properties, as photoconductors or in electronic components, corresponding photoconductive layers, an electrophotographic recording material and a method for enhancing the photoconductivity.

Abstract: A method of reading bar code symbols includes determining one or more parameters based upon the quantity and/or quality of the data which is being acquired, and providing the user with information concerning that parameter. The parameter may, for example, be the rate at which code words in the symbol are being read, and that information may be passed to the user by way of an LED which flashes at a rate which varies with the data acquisition rate. For a given bar code symbol being read, the rate of flashing varies with the position of the bar code reader with respect to the symbol. To improve the data acquisition rate, the user simply moves and/or rotates the bar code reader with respect to the symbol in a direction which causes the rate of flashing to increase. The invention extends to a bar code reader having means for providing an indication to a user of the relative suitability, for optimal reading of a symbol, of the current position of the reader.

Abstract: A electro-optical memory includes a substrate on which is printed (or otherwise inscribed) a complex symbol or "label" or "bar code" of a high density two-dimensional symbology. The bar code contains component symbols or "codewords" which are placed in row and column formation, with a variable number of codewords per row, and a variable number of rows. The symbology utilizes implicit bar code encoding scheme for implicit encoding the number of rows and the number of columns of codewords, as well as a predetermined amount of error correction. The symbology is capable of supporting a fixed number of bar code variants, with each variant having a predetermined number of rows and columns of codewords, and a predetermined error correction capability. For some codewords the implicit encoding scheme is combined with a gray coding scheme to reduce the inter-row codeword crosstalk.

Abstract: The use of low molecular-weight or polymeric organic compounds which are present in the columnar-helical phase and have liquid-crystalline properties, as photoconductors or in electronic components, corresponding photoconductive layers, an electrophotographic recording material and a method for enhancing the photoconductivity.

Abstract: A scanner determines whether a target is a bar code symbol and, if so, whether that symbol is one-dimensional or two-dimensional. For two-dimensional symbols, the scanner aligns a scanning pattern with the symbol and expands the scanning pattern to reach only to the top and bottom edges of the symbol, not beyond. The scanner also has a microprocessor-control scanning engine that uses a coil to drive a scanning element and pick up feed back signals from the scanning element. A pulse-width-modulated regulator also provides fast and efficient operation for driving the coil. The scanning engine can also be designed to generate a pattern that precesses across the target, and a powerful interface to the scanning engine allows decoding and control logic to work efficiently with and independently of the scan engine.

Abstract: Disclosed the use of organic materials having a specific conductivity of less than 10.sup.-2 S/cm and a nonionic charge carrier mobility greater than 10.sup.-4 cm.sup.2 /Vs as charge transport medium, with the proviso that an increase in the charge carrier concentration by a factor of 10 or more is not caused in this organic material by light absorption, and corresponding electrochemical cells.

Abstract: A method and apparatus for increasing the information density of a bar code symbol by generating multiple constituent bar code symbols, wherein each one is formed in a different color selected from a group of various primary colors, and overlaying each differently colored symbol on top of each other, thus forming an aggregate bar code symbol of various colors. In areas where the differently colored bars overlap each other, colors distinct from those in the original group of colors are formed. The aggregate bar code symbol is scanned by a solid state imaging device, and the scanned image is resolved by image processing techniques into the three constituent bar code symbols of the various colors. Each bar code symbol is then individually processed and decoded in accordance with the particular symbology used to encode the constituent bar code symbols.

Abstract: A scanner determines whether a target is a bar code symbol and, if so, whether that symbol is one-dimensional or two-dimensional. For two-dimensional symbols, the scanner aligns a scanning pattern with the symbol and expands the scanning pattern to reach only to the top and bottom edges of the symbol, not beyond. The scanner also has a microprocessor-control scanning engine that uses a coil to drive a scanning element and pick up feed back signals from the scanning element. A pulse-width-modulated regulator also provides fast and efficient operation for driving the coil. The scanning engine can also be designed to generate a pattern that precesses across the target, and a powerful interface to the scanning engine allows decoding and control logic to work efficiently with and independently of the scan engine.