Introduction
Barcodes are simple yet capable. They store data and track products in a wide range of ways. Developers of barcode readers are constantly improving their capabilities, refining technology, and increasing flexibility. Therefore, manufacturers and logistics providers must regularly reexamine how they use barcodes in their businesses to optimize efficiencies and cost savings.
Achieving maximum read rates
Once barcode reading systems are in place, many organizations work toward limiting the number of no-reads and maximizing read rates.
A no-read is an unsuccessful attempt to read a barcode.
Read rate is a formula that represents the accuracy of barcode systems calculated by the number of barcodes that are read divided by the number of attempts. Read rates are generally expressed as a percentage and the closer to 100%, the better.
Read rate = successful reads / attempted reads
No-reads have many possible causes, including:
- Uncalibrated reader
- Creased labels
- Clogged label printer
- Items too close together
- Inadequate lighting
Every no-read requires that a package, part, or product be diverted and reworked manually, causing delays. Modern logistics and manufacturing lines process products at high speeds, and a slight difference in read rates can significantly impact throughput and costs.
How do you prevent no-reads?
Stopping no-reads requires preventative and corrective measures. Barcode verifiers and standards-based grading are preventative tools that determine the readability of barcodes and check if they meet standards for specific industries.
Many barcode scanner suppliers use corrective tools such as artificial intelligence (AI) and proprietary decoding algorithms to read damaged or obscured barcodes.
Image-based barcode scanners enable users to analyze no-reads and isolate barcode issues. These readers generally have more advanced image formation and decoding features than laser scanners.
Barcode verifiers grade code quality based on global standards.
Label placement
Barcodes should be applied so that they can be easily read by a barcode scanner: away from packaging edges, uncreased, and flat.
Sometimes, packages include multiple barcodes or old labels, or codes may have surface damage. In these cases, an automated label placement guidance and verification system can find optimal locations for labels and verify correct placement.
Working distances
In many barcode reading applications, there may be frequent changes in working distance, different kinds and orientations of barcodes, and smaller lots of varied products that require variations in lighting. Establishing optimal read setups that take account for all factors can be cumbersome, and even after the setups are established, switching from one to another can take time, reducing throughput.
Liquid autofocus lets readers quickly find the optimal working distance between one item and the next, ensuring high read rates regardless of the object’s dimensions.
Automated systems can find the best location for labels.
A high speed liquid lens adjusts to different working distances.
Lighting
Better lighting quality and compatibility are often overlooked ways to maximize barcode read rates. Improved lighting can result in significant increases in read rates at moderate cost.
Increasing the readability of DPM codes requires specific lighting solutions. Lights can be deployed on the code at various angles, diffused, and have multiple colors and intensities. The goal is to create a homogenous and glare-free image that maximizes the contrast within the code and between the code and its background.
Common lighting and image formation technologies include:
- Dark-field illumination: Dark-field lighting involves illuminating the DPM code at a low angle to emphasize texture differences. Light from the surface is reflected away from the camera, minimizing glare.
- Diffuse illumination: Creates an even background, making a code more readable against curved or reflective backgrounds. This is particularly effective when the light can be placed close to the barcode.
Dark-field lighting.
Diffuse lighting.
High-dynamic range (HDR) and HDR+
High-dynamic range (HDR) and HDR+ are imaging technologies that increase an image's spectrum of bright and dark areas. HDR+ uses an advanced algorithm that optimizes contrast in localized areas of the image where contrast is more important.
Using a barcode reader with these technologies significantly increases code-reading capacity and capability.
Left: An image without HDR shows a single barcode being read. Right: The same image with HDR+ and 5 codes read.
Optimizing barcode performance
Barcode performance monitoring systems can increase productivity, analyze trends, monitor changes, and uncover why no-reads occur. These platforms collect essential device data and display it in customizable dashboards to help facility managers identify meaningful trends and intervene quickly if performance declines. Performance monitoring software allows employees to manage multiple barcode readers simultaneously to set user-level access and manage configuration files more quickly.