Schaumburg, Ill.—New toys almost always pose new automation challenges. This time it was transparent and translucent miniature figure heads.

Denmark-based Lego Systems Inc. produces about 31 million miniature figures per year, from plastic molding to decorating and assembly. In the process department at Lego's U.S. manufacturing facility (Enfield, Conn.), several machines assemble the figures' upper bodies. Engineers there need to make sure the figures' heads are facing forward, but ran into orientation problems with existing sensing techniques when transparent or translucent heads were introduced recently.

"When you have a clear head with many colors painted on it, it's very difficult for a standard photo sensor to stop the head in a certain position," says Jim Janik, Lego's senior production engineer. After trying several fiber optic and laser solutions that usually saw through the heads, Mr. Janik tried Omron's E3MC RGB color sensor and found it could perform accurately and keep up with the assembly machine's rapid cycle times. Because head placement was previously done on a machine fitted with a slower, more expensive vision system, Mr. Janik says using the E3MC increased Lego's miniature figure production speed. For more information, visit www.controleng.com/info.