System for encoding and decoding data in machine readable graphic form
US5243655A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 16, 1992 |
| Grant date | Sep 7, 1993 |
| Priority date | — |
| Expiry date | Mar 16, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2019/06253
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for representing and recognizing data in machine readable graphic image form in which data to be encoded is entered into the system and a processor encodes the data into a two-dimensional bar code symbol and generates transfer drive signals representative of the symbol. A transferring device such as a printer transfers an image of the two-dimensional bar code symbol onto a carrier such as a card or paper document in response to the transfer drive signals. A recognition device converts the image on the carrier into electrical signals representative of the symbol by scanning the image. A low-level decoder decodes the signals by decoding each scan line into a vector of codeword values corresponding to the codewords in the two-dimensional bar code symbol, assigning a row number to each of the codeword values, and then filling in a two-dimensional matrix with the codeword values. A high-level decoder further decodes the codeword values into data which can then be output for processing or use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.