Working principle: Light pen is the first hand-held contact bar code reader. When in use, the operator needs to contact the light pen with the bar code surface. A small light spot is emitted through the lens of the light pen. When the light spot passes through the bar code from left to right, the light will be reflected in the "empty" part and absorbed in the "bar" part, so a variable voltage will be generated inside the light pen, which will be used for decoding after amplification and shaping.

Classification:

Two-dimensional bar code scanners can be roughly divided into: handheld and fixed.

1, hand-held: that is, two-dimensional code scanning gun. A barcode scanner that can scan the QR code, QR code and DM code of PDF4 17, such as DS6707. Symbolic DS6708 and so on.

2. Fixed: that is, a two-dimensional code reader, desktop, non-handheld, placed on a desk or fixed in a terminal device, such as SL-QC 15S of SUMLUNG.

Extended data:

Laser scanners can be used for non-contact scanning. Usually, when the reading distance exceeds 30cm, the laser reader is the only choice. Laser reading bar code has a wide density range, and it can read irregular bar code surface or through glass or transparent tape, because it is non-contact reading.

Therefore, the bar code label will not be damaged; Due to the adoption of advanced reading and decoding system, the success rate of first reading recognition is high, and the recognition speed is faster than that of light pen and CCD, and the recognition effect is good for bar codes with poor printing quality or fuzzy; The bit error rate is extremely low (only about one in three million); Laser readers have good impact and fall resistance, such as SymbolLS4000 series scanners, which can prevent falling on 1.5m concrete floor.

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