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:
Mar. 15, 2016
Filed:
Mar. 12, 2013
Sony Corporation, Tokyo, JP;
Kouji Miyata, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
[Object] To lower a mechanical resonance sharpness and reduce oscillations near a minimum resonance frequency, to thereby improve the sound quality. [Solving Means] A speaker unit includes: a magnet that generates a magnetic force; a magnetic gap that causes the magnetic force to act; a yoke that is provided to be partially opposed to the magnet and forms a magnetic circuit that guides the magnetic force of the magnet to the magnetic gap; a coil bobbin that is formed in a tubular shape and is set to be axially vibratable with respect to the magnet and the yoke; a coil that is wound around the coil bobbin and partially placed in the magnetic gap; a cone that is vibrated in accordance with vibration of the coil bobbin; an edge that retains the cone at almost a center; and a frame that fixes each of the edge and the yoke, in which into the magnetic gap a magnetic fluid is injected, the magnetic fluid is set to have a viscosity equal to or larger than a predetermined value and a mechanical resonance sharpness is set to be equal to or smaller than 1.0, and sound proportional to a current is output by current drive.