Today, the detection of data matrix codes and barcodes in handling and production processes usually involves vision sensors. However, the quality of the image has a decisive impact on the efficiency and stability of the reading process. Sensor and vision specialist, SensoPart, shows how advances in technology are meeting increasingly complex demands from industry.
Printed or DPM data matrix codes or barcodes are applied to components or batches to guarantee full traceability during industrial processes. These codes are then read at various points along the production and packaging lines, and individually tracked. The challenges of reliable code reading vary depending on the type of product to be identified. Problems typically arise when reading codes at long or fluctuating ranges, or simultaneously identifying several objects in one image section. Standard image resolutions of 0.5 to 1.5 megapixels are often insufficient in these cases.
Multiple codes at once
In the large analysis laboratories of the pharmaceutical and food industry, it is essential that samples are correctly identified and assigned to guarantee high output and consequently, economic success. Samples are handled fully automatically, with many test tubes transported on a sample tray (fig. 1).
This example can be handled by a VISOR V50 vision sensor from SensoPart which has a resolution of 2560 x 1936 pixels (approximately 5 megapixels) – more than three times the size of that of standard vision sensors. The sensor’s field of view or operating distance can be flexibly adapted to the most diverse requirements through the choice a suitable C-mount lens: A narrow image section allows the identification of small details at a long-range, while the simultaneous detection of multiple component characteristics or several individual components or codes is possible with a wide field of view. Different lighting sources are also available to suit the task.
In this application, the bottom of each test tube is marked with a unique data matrix code, which is read at the different processing stations. This is done by a vision code reader, positioned beneath each station. Fig. 2 shows that a sensor with a high image resolution can detect all the samples in a tray in a single image. This task previously required the installation of several cameras, involving complex assembly and wiring.
Deciphering poorly readable codes
In addition to its resolution-related advantages, the VISOR V50 offers other reading qualities that are highly valued by users of SensoPart’s VISOR Code Readers. The sensors not only read all industry-standard barcodes and data matrix codes but can also be combined with different lenses and lighting options to ensure very reliable analysis of extremely small printed or marked codes on problematic (curved, reflective or rough) backgrounds. With VISOR V50, a wide choice of C-mount lenses allows precise adjustment to the respective detection task. For applications in harsh, industrial environments, SensoPart is one of only a few manufacturers to offer a matching IP 67 protective casing.
High resolution in a compact design
With a resolution of 5 megapixels, the VISOR V50 is unique among vision sensors of this compact size. In addition to the version VISOR V50 Code Reader, the sensor comes in other variants pre-configured for specific applications: VISOR V50 Object, VISOR V50 Robotic, VISOR V50 Solar and VISOR V50 Allround. All sensor variants, except for code readers, are optionally available with a colour chip. A uniform, intuitive operating concept facilitates the setup and configuration of the sensors.