The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 24, 2006
Filed:
Dec. 30, 2002
Tsuyoshi Kimura, Tokyo, JP;
Atsunao Shinoda, Tokyo, JP;
Kuniaki Ohsawa, Kanagawa, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
To provide a loudspeaker broadcasting system and a loudspeaker broadcasting apparatus which can perform a loudspeaker broadcasting of appropriate contents at each block without reducing sound clearness. Bi-directional speakerswhich performs sound-reinforcement having high intelligibility, and fire detecting sensorswhich detect fire occurrence in a tunneland send fire occurrence signals are placed in the tunnelin the tunnel extending direction. In an emergency such as a fire, emergency broadcasting is performed through each bi-directional speakerat each of the predetermined blocksin the tunnel. The emergency broadcasting is different in contents at each block, and it is alternately performed at the adjacent blocks. Further, the frequency components having a long reverberation time is removed from the loudspeaker broadcasting through the bi-directional speaker