Diaphragm and loudspeaker unit using the same
AssigneeSanyo Electric Co., Ltd.
InventorYuki Hatanaka
Life of this patent
Estimating the term…
Abstract
A diaphragm, and a loudspeaker unit using the same, capable of providing better low-tone characteristics than conventional ones. A loudspeaker unit includes a base frame and a cover plate joined to each other to provide a flat casing. Arranged in the casing are a diaphragm and a drive mechanism for vibrating the diaphragm. The diaphragm consists of a rectangular area and a pair of semi-elliptic areas, spreading rightward and leftward from the rectangular area, and has an elliptic central portion having its major axis in the longitudinal direction of the diaphragm and a peripheral portion spreading around the central portion. The central portion includes an adhesive layer for fixing a coil, laid on a central area of a diaphragm body, and is formed thicker than the peripheral portion.
Claims5
A diaphragm for a component of a loudspeaker for a small electronic device, the diaphragm comprising:
- orthogonal long and short axes on a plane,
- a central portion having the intersection of the long and short axes as the center thereof,
- a peripheral portion spreading around the central portion,
- wherein the central portion being formed thicker than the peripheral portion,
- the diaphragm is configured to vibrate with an outer circumferential edge of the peripheral portion which has a fixed end, wherein
- the outer circumferential edge line of the peripheral portion is composed of two first sections each intersecting with the long axis and two second sections each intersecting with the short axis, each of the two first sections describes a curve of varying curvature axis and has a minimum curvature radius at the intersection with the long axis, and each of the two second sections has a straight line in parallel to the long axis, wherein
- the border line between the peripheral portion and the central portion describes a curve having a minimum curvature radius at an intersection with the long axis and a maximum curvature radius at an intersection with the short axis, and
- wherein the peripheral portion is shaped such that a width thereof radially extending from the intersection is smallest on the short axis, and largest on the long axis, and the width monotonically increases from a minimum width on the short axis to a maximum width on the long axis.
A loudspeaker comprising:
- a flat casing containing a diaphragm having orthogonal long and short axes on a plane,
- a drive mechanism for vibrating the diaphragm,
- the drive mechanism comprising a toroidal coil fixed to the diaphragm,
- a toroidal magnet surrounding the coil, and
- a bottom plate partly projecting into the central space of the coil,
- the diaphragm comprising:
- a central portion having an intersection of the long and short axes as a center thereof, and
- a peripheral portion spreading around the central portion,
- the central portion being formed thicker than the peripheral portion,
- the coil being fixed to the central portion 31, the outer circumferential edge of the peripheral portion being coupled to the casing, wherein
- the outer circumferential edge line of the peripheral portion in the diaphragm is composed of a first two sections each intersecting with the long axis and a second two sections each intersecting with the short axis, each of the first two section describes a curve of varying curvature axis and has a minimum curvature radius at the intersection with the long axis, and each of the second two sections has a straight line in parallel to the long axis,
- the border line between the peripheral portion and the central portion describes a curve having a minimum curvature radius at an intersection with the long axis and a maximum curvature radius at an intersection with the short axis,
- wherein the peripheral portion of the diaphragm is shaped such that a width thereof radially extending from the intersection is smallest on the short axis, and largest on the long axis, and the width monotonically increases from the minimum width on the short axis to the maximum width on the long axis.
Dependencies are inferred from the claim text.