Patch codes are different from typical barcodes that have been explained earlier. Patch barcodes are basically codes consisting of 6 sets of distinct barcode patterns which are mostly used for document and file separation. Patterns used in patch barcode are referred as 1, 2,3,4,6 and T barcode patterns. These patterns are organized collectively to give an overall meaning and connotation to the patch barcode. These patterns are in the form of black and white bars which are arranged horizontally or vertically, running parallel to each other. Following are two of the six patterns used in Patch barcodes.
Pattern 3
Pattern T
History
Originally, patch codes were developed by Kodak. Patch codes were used to signal the data reading applications by sending commands to them. Application used to decode the signal of the patch code and process that accordingly.
Functionality
As aforementioned, patch codes are used for identifying desired document or milestones in bulk of documents. Following are some of the functionalities that patch codes perform in bulk of documents.
· They are used to signal the end of a particular document.
· Total number of pages in a document or total number of paragraphs.
· Used to calculate scan depth change.
Advantages
Patch codes possess all the advantages of a typical linear barcode. Some of the advantages are enlisted below.
· Simple and straight forward encoding and decoding techniques.
· No advanced user and employee training required understanding the barcode.
· Can be decoded and encoded using simple but expensive barcode devices.
Disadvantages
· Fault tolerance of patch code is limited as compared to other barcodes and code once destroyed or damaged cannot be decoded easily.
· Patch code has low density but it does not impact the overall performance of the code because its basic functioning is to mark and count end of documents and pages respectively.
General Instructions
Following are some of the instructions which must be followed for proper scanning of the patch code:
· Bars of the patch should be parallel to the leading edge of the document.
· The distance between patch code and any other printed information on the document should be at least 0.25 inches.
· A patch code of size 2.5 inches is considered standard. This size is ideal for scanning even if the barcode’s position is slightly changed.
· Patch code’s distance from the leading edge should not be greater than 3.75 inches.
· Codes should be printed with carbon based black ink.
· Patch code’s material should be such that it should reflect less than 20% of the light.
· Patch code should never be printed on glossy paper.
Applications
Patch codes are used in all such domains where documents play a key role. Following are some of the application areas of patch codes:
· In libraries to store and mark books.
· In universities and educational institutions.
· Patch codes are widely used in banking and financial institutions where bulk of documents need to be scanned in shorter time.
· Insurance companies also employ patch codes to keep track of the insurance documents.
Conclusion
Patch codes are different from conventional barcodes in terms of its usage. All the barcodes are usually general purpose and have variety of applications whereas patch codes are limited to documentation industry.