Cognex (CGNX) Q3 beats expectations as revenue rose 7% Y/Y, with solid sales growth out of the Americas, China and Europe. Gross margin also rose slightly to 76%. The company lowers FY11 guidance however, on projected weakness in its semiconductor and electronics businesses. For Q4, revenue is seen between $80M - $83M , below expectations of $85M. Separately, the company said it approved a stock buyback plan for up to $80 million in shares. Shares -7.3% AH.