Irvine Sensors Corp. has purchased 70 percent of the stock of Optex Systems Inc., a Richardson, Texas-based manufacturer of optical sighting systems and assemblies, mainly for US Department of Defense applications. The Costa Mesa, Calif., company plans to integrate some of its night-vision and laser technologies with Optex’s optical sights to expand the customer base for both companies. The acquisition is expected to accelerate Irvine Sensors’ transition to a product-dominated business. Optex delivers high-volume products under multiyear contracts to many of the same customers who support Irvine’s vision systems business.