Because the barcodes all start with 6 and 9, which represent mainland China.

Universal product barcodes generally consist of a prefix part, manufacturer code, product code and check code. The prefix code in the product barcode is a code used to identify the country or region. The coding authority is in the International Article Numbering Association, such as 00-09 representing the United States and Canada.

45 and 49 represent Japan. 69 represents mainland China, 471 represents Taiwan, and 489 represents Hong Kong SAR. Empowerment of manufacturer codes In the article coding organizations of various countries or regions, China is assigned manufacturer codes by the National Article Coding Center.

Commodity code is a code used to identify commodities. The coding power is exercised by the product manufacturer itself, commodity barcode. The product barcode finally uses a 1-digit check code to verify the correctness of the 1-12th digit code from the left in the product barcode.

Commodity barcode refers to a symbol composed of a set of regularly arranged bars, spaces and corresponding characters, which is used to represent certain product information. The bars are dark and the spaces are light, used for scanning and reading with barcode reading equipment.

The corresponding characters consist of a set of Arabic numerals for people to read directly or input data into the computer through the keyboard. The information represented by this group of spaces and the corresponding characters is the same.

Extended information:

1. Coding rules

1. Uniqueness: the same product with the same specifications corresponds to the same product code, and the same product with different specifications Should correspond to different product codes. Different product codes are assigned according to the different properties of the product, such as weight, packaging, specifications, smell, color, shape, etc.

2. Permanence: Once the product code is assigned, it will not be changed and is lifelong. When such a product is no longer produced, its corresponding product code can only be put on hold and cannot be reused or allocated to other products.

3. Meaningless: In order to ensure that the code has sufficient capacity to adapt to the needs of frequent product updates, it is best to use meaningless sequence codes.

2. Recognition Principle

To convert a barcode compiled according to certain rules into meaningful information, it requires two processes: scanning and decoding. The color of an object is determined by the type of light it reflects. White objects can reflect visible light of various wavelengths, while black objects absorb visible light of various wavelengths.

So when the light emitted by the barcode scanner light source is reflected on the barcode, the reflected light irradiates the photoelectric converter inside the barcode scanner. The photoelectric converter converts the reflected light signal into corresponding electrical signal.

According to differences in principles, scanners can be divided into four types: light pen, red light CCD, laser, and image. The electrical signal is output to the amplifier circuit of the barcode scanner to enhance the signal, and then sent to the shaping circuit to convert the analog signal into a digital signal.

The width of the white bars and black bars is different, and the duration of the corresponding electrical signals is also different. The main function is to prevent the quiet zone from being insufficiently wide. The decoder then determines the number of bars and spaces by measuring the number of 0,1 pulse digital electrical signals.

Distinguish the width of bars and spaces by measuring the duration of the 0,1 signal. The data obtained at this time is still messy. To know the information contained in the barcode, you need to replace the barcode with the corresponding numbers and character information according to the corresponding encoding rules (for example: EAN-8 code).

Finally, the computer system performs data processing and management, and the detailed information of the item is identified.

Baidu Encyclopedia-Barcode