Wednesday, June 20, 2018
Publication Date: 07/1/2008
Archive >  July 2008 Issue >  Partnering > 
Accurate Part Reading Using High-Performance Vision

Sensor used to identify location co-ordinates or fiducials.

With the overriding market trend for smaller products across many industry sectors, companies are obliged to review and redesign their products on a regular basis. Particularly relevant for devices such as mobile phones and Personal Navigation Devices (PND), the demand for more compact units is continually on the rise. This was the situation for Sarantel Ltd.

The company develops and manufactures what are reportedly the world's most advanced miniature filtering antennas for mobile, wireless and handheld devices. Founded in 2000 as a VC-funded technology spinoff headquartered in a garage, the company now employs over 100 staff in locations worldwide. In 2004 the European Tech Tour identified Sarantel as one of the Top 25 high growth technology companies in the UK. ( Changes in the required size of antennas have led the company to invest in a vision system which offers higher resolution capability. Founded in 2000 as a VC-funded technology spin-off headquartered in a garage, the company now employs over 100 staff in locations across the globe. In 2004 the European Tech Tour identified Sarantel as one of the Top 25 high growth technology companies in the UK. (See  )

The Challenge
The main issue with the original vision system was a lack of flexibility within the program, and with the ever-shrinking size of the product, the sensor's ability to identify filters and pattern matches was being compromised.

Sarantel began looking for a new vision sensor to accurately read the required patterns and invested half a day in a vision seminar at Multipix, which certainly paid handsome rewards. Following a demonstration of the Cognex product line, Sarantel realized it had found the sensors capable of reading the required patterns on each antenna.

High-Performance Camera
The chosen sensor was the Cognex In-Sight 5401 camera plus PatMax, which offers the ability to match the part on the PC board assembly with an impressive 180° tolerance. The system also recognizes the individual part (e.g. is it part 1, 2, 3 etc.), offers easier on-site programming, and the ability to access the system remotely. Two Sarantel managers attended the free In-Sight training at the Cognex offices in Milton Keynes and, following their training, were able to integrate the system internally.

Each cylindrical antenna measures 9mm in height and 7.5mm in diameter and each tray containing the antennas is placed under the sensor for reading. The sensors are used specifically to identify four location co-ordinates or fiducials, on each part. These fiducials are used for part-tuning and laser-trimming so there can be no room for error. The positions are so small that accurate part location readings are vital, especially given the added challenge of parts arriving in a slightly different orientation each time.

On the Production Line
Ian Green, Maintenance Manager at Sarantel, commented, "We have been able to experiment a lot more with the quick nature of the programming. Overall, it has given us more flexibility and the ability to find the part itself more accurately. Cognex has allowed us to look into the future without forgetting our past. With the proven success of the In-Sight sensor, we intend to replace the existing sensors used on our production lines."

Sarantel is just one of the many companies that have benefited from attending a Cognex/Multipix imaging seminar. These free-to-attend seminars are held on a regular basis and Multipix welcomes anyone who is interested in learning more about machine vision.

Multipix Imaging Ltd was founded in February 1997, and specializes in the distribution of components to the Machine Vision Industry. Multipix has continued to expand building on an extensive portfolio of specialist cameras, frame grabbers, software, lenses, lighting and supporting products from European and North American manufacturers. (

Cognex Corporation designs, develops, manufactures, and markets machine vision sensors and systems, or devices that can "see." Cognex vision sensors are used in factories around the world to automate the manufacture of a wide range of items and to assure their quality. The company is s world leader in the machine vision industry, having shipped more than 350,000 machine vision systems, representing over $2 billion in cumulative revenue, since the company's founding in 1981. In addition to its corporate headquarters in Natick, Massachusetts, the company also has regional offices and distributors located throughout North America, Japan, Europe, Asia, and Latin America.

Contact: Cognex Corp., One Vision Dr., Natick, MA 01760-2059 877-264-6391 or 508-650-3000 fax: 508-650-3333 Web: or

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