Clock free two-dimensional barcode and method for printing and reading the same
CA 2192008 C · Owner: Matsushita Electric Industrial Co. Ltd. · Inventors: Esakov, Jeffrey; Lopresti, Daniel; Zhou, Jiangying
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Inventive two-dimensional barcodes, each having encoded digital information in a bitmap representing preferably randomized encoded data bits are printed onto, a printed medium. The bitmap may further include a plurality of block identifiers, spaced a predetermined number of encoded data bits apart, which are used to make corrections for missing or added data bits when the barcode is decoded. Upon decoding a barcode printed on the printed media, the digital information is scanned and the number of horizontal and vertical edges in each respective column and row of the barcode are determined. An edge is determined by selecting a pixel and determining if the two pixels adjacent to the selected …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 4, 1996 and granted February 12, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 4, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 4, 2018.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.