Tue Jun 14 14:12:13 CST 2022
Bar code scanner, also known as bar code reader, bar code scanning gun, bar code scanner, bar code scanning gun and bar code reader. It is a reading device used to read the information contained in the bar code. Using the optical principle, the content of the bar code is decoded and transmitted to the computer or other equipment by data line or wireless. It is widely used in supermarkets, logistics express and libraries to scan bar codes of goods and documents.
Ordinary bar code readers usually use the following four technologies: light pen, CCD, laser and image red light.
Light pen is the first hand-held contact bar code reader, and it is also the most economical bar code reader.
When in use, the operator needs to touch the light pen to the surface of the bar code and send out a small light spot through the lens of the light pen. When the light spot crosses the bar code from left to right, the light will be reflected in the "empty" part and absorbed in the "bar" part. Therefore, a changing voltage will be generated inside the light pen, which will be used for decoding after amplification and shaping.
Principle of laser gun
Laser scanner is relatively expensive among various scanners, but it can provide the highest functional indicators, so it is widely used in various industries.
The basic working principle of the laser scanner is as follows: the hand-held laser scanner emits a beam of light through a laser diode and irradiates it on a rotating prism or a swinging mirror. The reflected light passes through the reading window and irradiates the bar code surface. The light returns to the reader after being reflected by a bar or empty, and is collected and focused by a mirror, It is converted into electrical signal through photoelectric converter, and the signal will be decoded by scanner or decoding software on the terminal.
Laser scanners are divided into hand-held and fixed forms: hand-held laser guns are easy to connect and flexible to use. Fixed laser scanners are suitable for occasions with the largest reading and smaller bar codes, effectively freeing hands to work.
Advantages: laser scanner can be used for non-contact scanning. Generally, when the reading distance exceeds 30cm, laser reader is the only choice; Laser reading bar code has a wide range of density, and can read irregular bar code surface or through glass or cellophane. Because it is non-contact reading, it will not damage the bar code label; Because of the more advanced reading and decoding system, the first reading recognition success rate is high, the recognition speed is faster than light pen and CCD, and the recognition effect of bar codes with poor printing quality or fuzzy is good; The bit error rate is very low (only about one in three million); The laser reader has good shockproof and fall proof performance. For example, the scanner of symbolls4000 series can fall proof on 1.5m cement floor.