What do you know about barcode scanners?

What do you know about barcode scanners?

Barcode scanner

Barcode scanner, also known as barcode reader, barcode scanning gun, barcode scanner, barcode scanning gun and barcode reader. It is a reading device used to read the information contained in the barcode. Using the optical principle, the content of the barcode 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 barcodes of goods and documents.

Four laser technologies

Ordinary barcode readers usually use the following four technologies: light pen, CCD, laser and image red light.

working principle

Light pen is the first hand-held contact barcode reader, and it is also the most economical barcode reader.

When in use, the operator needs to touch the light pen to the surface of the barcode and send out a small light spot through the lens of the light pen. When the light spot crosses the barcode 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.

advantage

Contact with the barcode to read, which is the barcode to be read; The length of reading barcode can be unlimited; Compared with other readers, the cost is lower; There are no moving parts inside, which is relatively solid; Small size and light weight. Disadvantages: the use of light pen will be subject to various restrictions. For example, it is not suitable to contact and read barcodes on some occasions; In addition, the light pen can play its role only when reading the barcode with specified density and good printing quality on a relatively flat surface; Moreover, operators need some training to use it, such as reading speed, reading angle and improper pressure will affect its reading performance; Finally, because it must be read in contact, when the barcode is damaged due to improper storage, or there is a protective film on it, the light pen cannot be used; The light pen has low first reading success rate and high bit error rate.