Barcode or barcode is a graphic identifier that arranges a plurality of black bars and blanks with different widths according to certain coding rules to represent a group of information. Common bar codes are parallel lines composed of black bars (referred to as bars) and white bars (referred to as spaces) with great differences in reflectivity. Barcode can indicate the country of production, manufacturer, commodity name, date of production, book classification number, starting and ending place, category and mailing date, so it has been widely used in many fields such as commodity circulation, book management, post and telecommunications management, banking system and so on.

Bar code recognition principle

The color of a barcode scanner object is determined by the type of light it reflects. White objects can reflect various wavelengths of visible light, while black objects can absorb various wavelengths of visible light. Therefore, when the light emitted by barcode scanner light source is reflected on the bar code, the reflected light shines on the photoelectric converter inside barcode scanner, and the photoelectric converter converts the reflected light signal into a corresponding electrical signal according to the different intensity, and then outputs it to the amplifier circuit in barcode scanner to enhance the signal, and then sends it to the shaping circuit to convert the analog signal into a digital signal. The widths of white bars and black bars are different, and the duration of corresponding electrical signals is also different. Then, the decoder determines the number of bars and spaces by measuring the number of pulse digital electrical signal 0, 1, and determines the width of bars and spaces by measuring the duration of 0, 1 signal. According to the corresponding coding rules, barcode scanner can convert bar code symbols into corresponding digital and literal information, and finally the data is processed and managed by the computer system, so that the detailed information of articles can be identified.

[Edit] Advantages of Barcode

Strong reliability. The reading accuracy of bar code far exceeds manual recording, and an error will appear every 15000 characters on average.

High efficiency. The reading speed of bar code is very fast, which is equivalent to 40 characters per second.

Low cost. Compared with other automatic identification technologies, bar code technology only needs a small sticker and a relatively simple optical scanner, and the cost is quite low.

Easy to make. Bar code writing is very simple, just need to print, so it is called "printable computer language".

Simple operation. Bar code recognition equipment is simple in structure and convenient to use.

Flexible and practical. Bar code symbols can be input by manual keyboard, can also be combined with related equipment to realize automatic identification, and can also be linked with other control equipment to realize automatic management of the whole system.