Evolution of Barcode Scanners

Key Takeaways

Here are the key points on the evolution and impact of barcode scanners:

Barcode scanners have evolved from early prototypes using movie sound technology to advanced systems that drive automation.
There are many types of barcodes and barcode scanners, each suited for different applications.
Innovations like high-dynamic range plus (HDR+) are improving the user experience of modern barcode scanners.

History of the scanner

One of the earliest barcode readers was derived from an old DeForest movie sound system. The photosensitive tube detected light variations and converted them into numbers, rather than the sound of Cary Grant’s voice.

In the early 1960s, railways experimented with a system that used colored strips on railcars to encode a 10-digit number that was decoded by an arrangement of colored lights and intensity-detecting sensors. This system failed commercially but was later developed into one that used the light cast by the newly-developed laser to decode a black and white barcode. The easily moved laser would pass over the code repeatedly while decoding giving us the origin of the term “barcode scanner.” 

The parts of a barcode scanner

In general, a barcode scanner has three essential parts: a light source, a sensor that detects the variations in the light reflected from the barcode, and a decoder that converts those variations into data that can be used by a point-of-sale system or enterprise resource planning (ERP) software, or other systems.

For a long time, the technology available to scan barcodes meant they were limited to those familiar one-dimensional (1D) linear arrangements of thick and thin black lines. 1D barcodes can be regarded as a sort of optical Morse code, with narrow and wide lines instead of dots and dashes. They were generally read by laser scanners, which used electronically controlled mirrors or prisms to sweep the laser beam horizontally across the black lines. Laser scanners can be stationary or handheld and are still widely used. Some handheld laser scanners are called “RF guns” or “RF scanners,“ which refers not to the way they scan, but to the way they communicate the data they generate—by a radio frequency signal.

By the 1970s, fixed raster scanners used lasers and a combination of mirrors to create 2D patterns that could read 1D barcodes from any angle. These are still common in grocery store checkouts.

The introduction of CCDs and 2D codes

In the 1990s, charge-coupled device (CCD) scanners used a single row of photocells on a chip to function as a 1D camera. They were cheaper than laser scanners and competed with them successfully in the market. However, this technology became more important when, by the 2000s, cheaper and more capable chips allowed for two-dimensional (2D) arrays, and thus the ability to read 2D codes. 2D codes can hold a much larger amount of information in a smaller area than 1D barcodes. But, the 2D fixed raster scanners could only read limited types of 2D codes.

The need for image-based barcode readers

Industries such as healthcare, logistics, and retail rely on the information density of 2D codes, which now drive the barcode reader market and the need for 2D imagers or image-based barcode readers. A wide range of high-resolution CCD and complementary metal-oxide semiconductor (CMOS) cameras with sophisticated embedded processors, both fixed-mount and handheld, have transformed logistics and supply chain management.

Image-based barcode readers of all kinds record an image and run image processing algorithms to detect 1D and 2D barcodes. They can also read 2D codes that are direct part marked (DPM) on medical devices, automotive parts, and other durable goods via dot peen or laser etching.

Difficult 2D Barcodes — Examples of 2D DPM barcodes.

Capturing and storing images of barcodes as they are read means that “no-reads” or “misreads” can be analyzed after the fact. Reviewing these images can help identify the cause, whether a clogged print head, missed label, or poor lighting. This ability to gather performance feedback for process improvement is a significant benefit of moving to image-based technology.

The continuing evolution of barcode scanners

A range of new technologies are also transforming barcode reading. The introduction of high dynamic range (HDR) technology is improving image quality, high-speed liquid lenses are enabling increased depth of field, and a single reader with multiple image sensors is improving the location and reading of barcodes in various locations.