A wide range of bar code types to meet the needs of many industries

2023-05-26 | 495 view
Bar codes are optical machine readable representations of data. The mapping between the barcode and the data it represents is called the symbol system.

 

Bar codes are optical machine readable representations of data. The mapping between the barcode and the data it represents is called the symbol system. The three main categories of symbolic systems are linear (1D), stacked, and matrix (2D). The most common barcodes represent data in the width and spacing of parallel lines, known as linear or 1D (one-dimensional) barcodes or symbol systems. Linear barcodes are one-dimensional, meaning that the unique information is horizontal and the same information is repeated in the vertical direction. You can truncate the height of the bar without losing any information. This allows symbols with printing defects, such as spots or gaps, to still be read. The higher the bar height, the more likely it is to be readable along at least one path of the bar code.

There are many one-dimensional symbols: UPC (the numeric Code on retail goods), Code 39 (numbers, uppercase letters, and 7 special characters), and Code 128 (all 128 ASCII characters) are three of the more popular.

Stacked bar codes are a group of linear bar codes stacked together. An example of a stacked symbol system is the PDF417 format used on airline boarding passes.

Two-dimensional bar codes appear as squares, dots, hexagons and other geometric patterns in the image, known as matrix codes or symbols. Although 2D systems use symbols other than bars, they are also commonly referred to as bar codes. Examples of QR codes include semacode, optimized for mobile phone use, and similar QR codes originating in Japan.

A one-dimensional barcode encodes only numbers or strings that can be entered into a database, whereas a two-dimensional barcode can actually hold the entire database. For example, you can embed an Excel spreadsheet in a two-dimensional barcode and use it as a portable database. Most QR codes can contain at least 2,000 characters per bar code. A typical one-dimensional barcode contains about 10-20 characters.