Self-clocking n,k code word without start or stop
View Patent ↗A referenceless self-clocking (n,k) bar code word allows conveyance of information without the need of any start and/or stop code pattern or other reference; a code word pattern is repeated at least in part without space therebetween according to a given n,k coding convention so that any k pair of adjacent data code elements sensed by any sensing means according to the n,k coding convention will consist of n units (e.g., bar code modules), thus allowing the data code elements of the code word to be decoded most accurately without any reference pattern. One application of this coding is on round or cylindrical objects like coins, casino chips and the like, and this coding is also well suited for linear or other coding applications wanting to convey coded information without the use of a start/stop code or reference pattern using n,k coding. This coding may or mayn't include error control, for example, as disclosed herein.
1. An n,k self-clocking bar code word which includes portions having either first or second properties by which the portions are distinguished, the bar code word defining with the first and second properties a code word and at least part of the code word adjacent to at least one end of the code word without space therebetween, a code word comprising n modules defined by substantially equal extents of either of the properties which are arranged to define k elements comprising one or more contiguous modules with the first property and k elements comprising one or more contiguous modules with the second property, and the at least part of the code word adjacent to at least one end of the code word comprising one or more elements of the code word extending from an end of the code word.
2. A self clocking bar code word without a start or stop code, comprising an n,k bar code word comprised of n modules and k elements of the same bar code property, and adjacent to one side of said bar code word without a space therebetween and extending therefrom one or more additional elements from the other side of the bar code word.
3. A method for self clocking a bar code word without a start or stop code, the bar code word including an n,k bar code word comprised of n modules and k elements of the same bar code property, the method comprising repeating adjacent to at least one end of the bar code word one or more elements from the other end of the bar code word extending from an end thereof without a space between the at least one end of the bar code word and the repeated bar code word elements.
4. A self clocking n,k bar code word without a start and stop code, comprised of n modules and k elements of each of two contrasting bar code properties, and arranged so that two ends of the bar code word abut without space therebetween.
5. A self clocking n,k bar code word without a start and stop code, comprised of n modules and k elements of each of two contrasting bar code properties, and adjacent to at least one end of the bar code word without space therebetween and extending therefrom one or more additional elements which repeat the elements(s) from the other end of the bar code word.
6. A system for deriving information represented by a self clocking n,k bar code word without a start and stop code comprised of n modules and k elements of each of two contrasting bar code properties, with at least one element from one end of the bar code word repeated adjacent to the other end without a space therebetween, comprising means for measuring k elements of each said properties, means for dividing said measurement by n, means to process the result to determine the module widths of said elements, and means to decode the element widths so that information represented by the bar code word may be derived therefrom.
7. A method for deriving information represented by a self clocking n,k bar code word without a start and stop code comprised of n modules and k elements of each of two contrasting bar code properties, with at least one element from one end of the bar code word repeated adjacent to the other end without a space therebetween, comprising: measuring k elements of each of the properties, dividing the measurement by n, processing the result to determine the module widths of the elements, decoding the element module widths and deriving the information represented by the bar code word.