Online juggernaut Amazon Inc. has unveiled its next generation of Kindle, Ring and Echo devices powered by artificial intelligence. The devices connect to Alexa+, its AI-infused personal assistant, which made its debut in February. The lineup, unveiled Tuesday in New York, includes new cameras for Ring's video monitoring device with AI facial recognition that allows users to register friends and family and notify them who is at the front door. Amazon also unveiled four new Echo devices revamped with Alexa+ that serves up personalized insights like whether the user left the front door unlocked after midnight. And Amazon’s Alexa+-infused Fire TVs will allow consumers to find special moments in a movie, like when Elsa sings “Let it Go" in “Frozen.”