Patent ID: 7929720

Claim:
A position detecting system comprising: a speaker system comprising an array speaker having a plurality of speakers arranged along at least one line, including at least a first speaker and a second speaker that are separated by a known preset distance and each output a measurement sound signal, and driving devices that drive respective ones of said plurality of speakers; a user terminal apparatus comprising a signal transmitting device that transmits a wireless signal to said speaker system, and a microphone; a position detecting device provided in a side of said speaker system, and said position detecting device detecting a position of said user terminal apparatus, wherein said signal transmitting device transmits the wireless signal to said position detecting device upon detecting that said microphone has received the measurement sound signal from one of said at least first and second speakers, and wherein said position detecting device comprises: a memory device storing the known preset distance between the first speaker and the second speaker; a receiving device that receives the wireless signal transmitted from said signal transmitting device of said user terminal apparatus; a timing device that measures a time elapsed since one of said at least first and second speakers is driven and until the wireless signal is received from said signal transmitting device of said user terminal apparatus; and a computing device that computes the position of said user terminal apparatus based on (i) a first time elapsed since said first speaker is driven and until a first wireless signal transmitted by said signal transmitting device in response to the measurement sound signal from said first speaker is received, (ii) a second time elapsed since said second speaker is driven and until a second wireless signal transmitted by said signal transmitting device in response to the measurement sound signal from said second speaker is received, and (iii) the known preset distance between the first speaker and the second speaker stored in the memory.