At first glance, the four Japanese men at the booth could have been doing anything on their MacBook Pros -- there wasn't a musical instrument in sight -- but upon closer inspection, they each appeared to be holding identical loupe-like devices, connected to each laptop via USB.

ENGADGET: Gocen optical music recognition can read a printed score, play notes in real-time (hands-on video)

The news comes as an inspection of the Japanese company that makes the batteries found no serious problem with the devices.

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