SAN FRANCISCO:-Samsung sent out invitations Friday for an October 11 event to launch a new mobile device under its Galaxy line. The invitation offered few details but the mention of “4x fun” led to speculation the about a new smartphone with four cameras or possibly a foldable handset. The South Korean electronics giant, the world’s leading smartphone maker, unveiled its latest flagship Galaxy Note 9 in August. Samsung and other device makers are looking for ways to boost momentum in a sluggish smartphone market.