A machine-readable matrix-type code has either repeated or non-repeated dot patterns in one direction representing digital characters which are read by a sensor moved in a direction which is generally normal to the patterns. The patterns of the code may be formed in a manner wherein the sensor views a portion of repeated patterns, or the code may be of lesser magnitude wherein the entire non-repeated pattern area is covered by the field of view of the sensor.
A data processing system, and method combine two alphanumeric data streams into a single bar code representation. Storing a first conversion table converts a first sequence of alphanumeric characters into a corresponding sequence of first bar code characters having character widths modulated in a first direction. A second conversion table converts a second sequence of alphanumeric characters into a corresponding sequence of second bar code characters having character heights modulated in a second direction orthogonal to the first direction. The system outputs a composite bar code sequence to represent both the first and the second sequence of alphanumeric characters.
A filing system is provided for locating a particular file contained in a file holder which contains a plurality of files. The apparatus includes a machine-readable code mounted on each of the files, a guide attached to each file holder, a scanner for reading the codes on the files in a file holder, and an indicator for indicating when the particular machine-readable code corresponding to the particular file is located. The apparatus uses an improved bar code in which character boundaries are eliminated and the numbers of ONE's and ZERO's in a code are variable, resulting in increased data density. The unique numeric values which result from the improved bar code sparsely populate the possible range of values, and therefore a mapping algorithm is provided to map the bar code values to a sequential numeric system for case of use. The improved bar code system uses repeating basic patterns of bars separated by a MARK bar, and a basic pattern can be reconstructed if the scan view includes only one MARK bar surrounded by ONE and ZERO bars. The improved apparatus also utilizes an inventive perpendicular file tab which positions the bar code accurately for the scanner. Border bars are provided to allow the scanner to separate bar codes from each other and to aid in determining if a bar code is defective or damaged.
When a decoding unit 6 fails in reading bar code information, a control unit 5 writes a corresponding error code into a ring table in the storage unit 4. In an error analyzing mode, the control unit 5 causes a measurement to automatically end when the decoding unit fails to read bar code information after the same bar code information is read a preset number of times or more, when the same bar code as that previously read is read and then bar code information different from that read by the preceding reading operation is read, or when a specific read error occurs. The indicator unit 7 indicates a number of the operations of reading bar code information and a read rate by changes of light colors emitted from light emission diodes of two colors, in a second normal measuring mode, and first and second test modes.
A readhead for reading text printed by a matrix printhead comprises an aligned array of side by side photodiodes (4). An optical system forms an image of a strip of the text support on the array. The image and the photodiode array are such that the image of a single printed dot of a character block normally covers an integer number of photodiodes. The array is periodically sequentially scanned to form an output signal which is digitized before being fed to a margin detector which determines margins above and below the character block. Signal blocks are stored after being analyzed by counting margin values and the number of "1" and "0" states. The process of the invention results in a signal which is effectively a reproduction of the signal originally used to print the character blocks.
A printed data strip (7) on a substrate (5) is provided including bit encoded information (23) and control information (15, 19, 27, 29) for an optical scanner. The encoded information is in a plurality of parallel, contiguous data lines (11) formed of bits of sequentially-encoded information, the bits being of uniform height and width. The data lines (11) start along a common line and, together, form an information portion (23) of sequentially-encoded data. The data lines (11) are transverse to the longitudinal dimension of the data strip (7). Associated with the encoded information on the printed substrate (5) are printed areas serving preliminarily to align the optical scanner with the data lines (17), and to set contrast levels (17), to maintain alignment during scanning (27, 29), and to set the vertical (19) and horizontal (15) rates of scanning. Means are provided to control and adjust the timing of each scanned data line by the optical scanner during the course of scanning.
