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:
Apr. 20, 1999
Filed:
May. 28, 1997
Takeshi Nakamura, Uji, JP;
Yoshiaki Heinouchi, Joyo, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A speaker has a substantially reduced size, is efficient in the low sound range and is unidirectional relative to the plane of installation or support of the speaker. The speaker includes a vibrator having a semispherical vibrating body made of a piezoelectric material polarized in a thickness direction. Electrodes are provided on the inner and outer surfaces of the vibrating body. A cavity is created inside of the vibrator. A sound path in the form of a horn includes inner parts of a first cylinder which communicates with the cavity, a second cylinder, a third cylinder, a fourth cylinder, a fifth cylinder and other cylinders. Cutouts functioning as openings of the sound path are disposed almost along the whole azimuth of the fifth cylinder at the outside of the horn relative to the plane of speaker support.