How Does Laser Bar Code Reader Work?

Laser Bar Code Reader  has permeated our daily life and is widely used in scanning supplies and barcode documents in supermarkets, logistics couriers, bookstores, etc. Today we will focus on what a barcode is and how barcode scanners work.

What is a barcode scanner?

Identity:

A Laser Bar Code Reader, also known as a barcode reader, barcode scanning gun, barcode scanner, barcode scanning gun, or barcode reader. A reader for reading the information contained in barcodes. It uses optical principles to decode barcode content and transmit it over data lines or wirelessly to a computer or other device.

Structure:

The structure of a barcode scanner is usually divided into three parts: light source, receiver, photoelectric converter, decoding circuit, and computer interface.

Operating principle:

A scanning gun is that the light emitted by a light source illuminates a Laser Bar Code Reader through an optical system. Light reflected by a photoelectric transducer is imaged by an optical system and interpreted by a decoder as a digital signal that is directly accepted by a computer.

4 Techniques Used in Barcode Scanners

A common Laser Bar Code Reader usually uses his four technologies: 

Pen reader principle:

The optical pen is the first type of handheld barcode reader and also the most economical barcode reader. In Laser Bar Code Reader the operator must touch the surface of the bar code with the light pen through the lens of the light pen to emit a very small spot of light. The 'blanks' reflect light and the 'bars' absorb light, creating a variable voltage inside the optical pen that is amplified and decoded.

Also read: Step by step instructions to choose a Laser Bar Code Reader

Principle of CCD reader:

CCD is an electronic coupling device and is more suitable for close range reading and contact reading. It's not as expensive as a laser reader and has no moving parts inside.

A CCD reader uses light from one or more LEDs to cover the entire bar code, the bar code image is transmitted into columns of light, individual photodiodes are sampled, and each bar or area is detected as adjacent. It is marked as "black" by the result. Or "white" to identify characters in barcodes. This means that the CCD reader reads the entire bar code portion rather than rotating to read each "strip" or "blank". converted into a readable electrical signal.

Laser scanner principle:

Laser Bar Code Reader are relatively expensive among scanners, but they are widely used in various industries because they can provide the most functional indicators.

The basic working principle of Laser Bar Code Reader is that a handheld laser scanner emits a light beam through a laser diode, a rotating prism or an oscillating mirror, and projects the reflected light onto the barcode surface through a reading window. . Light returns to the reader after a blank strip or reflection. This light is collected and focused by mirrors and converted into electrical signals by photoelectric transducers. The signal is decoded by the device's scanner or decoder.

Laser Bar Code Reader are divided into two forms. Handheld laser guns are convenient, easy to connect, and flexible to use. Fixed laser scanners are suitable for maximum opportunity to read the smallest barcodes, effectively freeing your hands.

Image type red light principle:

The image type red light Laser Bar Code Reader is a barcode reader that replaces the laser gun! The scanning depth of field is up to 30cm, coupled with a scanning speed of 300 times per second, for excellent code reading performance. Due to its unique image design, its decoding ability is so strong that common scanners cannot read the barcode, and the red light in the image is still easy to read. Through the smart interface, you only need to replace the cable to realize the keyboard. At the same time, RS232 serial port, USB and other interface conversion can also be directly connected to the laptop.