New MP3 players from electronics manufacturers such as Sony are destined for a demanding consumer market and cannot be compromised in any way. In Malaysia, Sony sought a barcode-reading and traceability solution for PCBs used in MP3 players. This kind of product tracking is essential to protect against costly recalls and product mix-ups, as well as to allow for "damage control" in the event of a problem.
Previously, badly read codes and the resulting rejection rates were proving costly in terms of rework and rejected units. With its old code-reading system incapable of rising to the challenge, Sony began using the In-Sight 5110 from Cognex (Natick, MA, USA; www.cognex.com) for code reading on PCBs for MP3 players.
Each PCB passes along a conveyer on nine production lines and is marked with a Data Matrix code containing product information in 10 characters measuring 1 x 1 mm. Production volume at the plant is 40,000 units a day, and so the reading solution deployed must guarantee a read rate of 100% to allow the production line to work nonstop and eliminate downtime. The serial number marked on each PCB must be identified and tracked. If the code reader cannot adjust to the product changeovers on lines, a serial number can be missed and data lost. No two read points are the same. Lighting, environment, or the way the piece is presented can differ greatly.
In-Sight 5110 ID readers are now installed on nine production lines, replacing the existing readers. Code-reading time is now 2 s/read. Code-reading success rate has increased from 95% to 100%. With a 100% successful code-reading rate, the production line no longer has to stop as a result of badly read code. And the line does not have to stop for product repositioning or focus adjustment. These factors are already saving Sony about $5000 a week.
TK Tan, staff engineer at Sony, Penang, says: "The fact that we have improved our code-reading times and increased our success rate to 100% saves us valuable time and boosts our production efficiency; we hope to implement these vision solutions elsewhere for other OCR applications."
