HIGH-TECH MEDICAL DEVICES: Sony's new alliance with Olympus will focus on producing endoscopes and other surgical tools packed with the Japanese electronic maker's three-dimensional imaging and super-clear "4K" display technologies. NEW CHALLENGE: Sony said it's not clear when the alliance's first products will become available. Medical equipment requires special regulatory approval that will take longer and be a learning curve for Sony, whose expertise is in gadgets and movies. THE VENTURE: Sony will invest $640 million, becoming Olympus' biggest shareholder. Olympus needs to shore up its finances after covering up massive losses dating back to the 1990s.
