1. Print layer

2. Protective layer

3. Reflective layer

4. Dye layer

5. Subfloor

All the pits have the same depth and length. A pit is only about half a micron wide and about 500 hydrogen atoms long. And there is such a pit in the stripe code. When the laser is mapped to the stripe code, if the laser shines on the land, 70% to 80% of the laser will be reflected back. If it shines on the pit, it can't reflect back the laser. Depending on the reflection and non-reflection, the machine can interpret the digital code of "0" or "1".

The principle of supermarket stripe code and train ticket stripe code is basically the same.

That's all. Thank you for your adoption.

Supplement: Barcode is a graphic identifier composed of bars and spaces with different widths and reflectivity according to certain coding rules (coding system), which is used to represent a group of numerical or alphabetic symbol information. That is, bar code is a group of parallel lines with different thicknesses and arranged at regular intervals. Common bar codes are composed of black bars (referred to as bars) and white bars (referred to as spaces) with different reflectivity.

Bar code scanner network home page-> & gt barcode scanner equipment barcode technical knowledge

Understand the principle of bar code recognition (bar code recognition principle)

I. Overview of Barcode-Barcode Recognition Principle (Barcode Recognition Principle)

Bar code was first proposed by N.T.Woodland of the United States in 1949. In recent years, with the popularization of computer application, the application of bar code has been greatly developed. Barcodes can indicate the country of production, manufacturer, product name, production date, book classification number, starting and ending place, category and mailing date, so they are used in commodity circulation, book management, post and telecommunications management, etc.

Bar code is a graphic identifier which is composed of bars and spaces with different widths and reflectivity, and is compiled according to certain coding rules (coding system) to represent a group of digital or alphabetic symbol information. That is, bar code is a group of parallel lines with different thicknesses and arranged at regular intervals. Common bar codes are composed of black bars (referred to as bars) and white bars (referred to as spaces) with different reflectivity.

Second, the composition of the bar code recognition system-bar code recognition principle.

In order to read the information represented by bar code, a bar code recognition system is needed, which consists of bar code scanner, amplification and shaping circuit, decoding interface circuit and computer system.

Because different colors reflect different wavelengths of visible light, white objects can reflect various wavelengths of visible light, while black objects absorb various wavelengths of visible light. Therefore, when the light emitted by the barcode scanner light source passes through the diaphragm and the convex lens 1 and shines on the black-and-white bar code, the reflected light is focused by the convex lens 2 and shines on the photoelectric converter, so that the photoelectric converter receives reflected light signals with different intensities corresponding to the white bars and the black bars. It is converted into a corresponding electrical signal and output to the amplification and shaping circuit. The widths of white bars and black bars are different, and the corresponding electrical signal duration is also different. However, the electrical signal corresponding to the bar code and space output by photoelectric converter is generally only about 10mV, so it cannot be used directly. Therefore, the electrical signal output by the photoelectric converter should be sent to the amplifier for amplification first. The amplified electrical signal is still analog. In order to avoid false signals caused by defects and stains in bar codes, it is necessary to add a shaping circuit after the amplification circuit to convert analog signals into digital electrical signals for accurate interpretation by the computer system. The pulse digital signal of the shaping circuit is converted into digital and character information by the decoder. It can distinguish the coding system and scanning direction of bar code symbols by identifying the start character and the end character. By measuring the number of pulse digital electric signal 0, 1, the number of bars and spaces can be determined, and by measuring the duration of signal 0, 1, the width of bars and spaces can be determined. Therefore, the number of bars and spaces for bar code symbols and the corresponding width and code system can be obtained. According to the coding rules corresponding to the coding system, bar code symbols can be converted into corresponding digital and text information, and sent to the computer system for data processing through the interface circuit.