JPS5838702Y2 - speaker device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flat-plate type diaphragm, and relates to an improvement in a speaker device that has excellent frequency characteristics by forming the diaphragm from a foam and making the center portion thicker than the outside.

In general, a flat plate type speaker is wound around a bobbin 7 housed in a magnetic gap 6 of a magnetic circuit 5 consisting of a magnet 1, top plays 1 to 2, a plate 3, and a pole piece 4, as shown in FIG. A flat plate type diaphragm 9 is driven by the voice coil 8 and a driving member 71 extending to the bobbin 7 and is supported so as to be able to freely vibrate.

By the way, the flat plate type diaphragm 9 has a honeycomb core 93 having a uniform and relatively thick thickness interposed between the upper and lower plates 91 and 92.

In such a diaphragm 9, the wall thickness near the diaphragm 9 to which the drive member 71 is attached is uniform, and the radiation surface is also flat, so resonance occurs in the diaphragm itself, which not only narrows the usable frequency range. The sound radiated from the edge and the sound radiated from the diaphragm are buffered by the corner portion formed by the mounting portion of the diaphragm edge, resulting in sound deterioration.

Also, Utility Model Publication No. 46-13069, Utility Model Number 50226
In the speaker device disclosed in Japanese Patent Laid-Open No. 51-77323, the central part of the diaphragm made of foam is gradually thickened from the outside. The side has a curved shape, but the radiation (front)
The surface side has a flat shape.

A diaphragm having such a configuration with a flat radiation surface emits radiation horizontally.

Therefore, the directivity was narrow. The present invention eliminates the above-mentioned drawbacks, and provides a flat speaker device that expands the frequency band, prevents sound buffering, and widens directivity.

An embodiment of the present invention will be described in detail with reference to FIG.

Note that the same parts in the figure as in FIG. 1 are given the same reference numerals and their explanation will be omitted.

In FIG. 2, the driving member 71 is fixed to a diaphragm 20 that is supported so as to vibrate freely, and the diaphragm 20 has a foam such as urethane foam filled between upper and lower plates 201 and 202, and its shape is that of an edge. The area around the attachment part 21 with 10 is thinned,
The wall thickness gradually increases toward the center, and the radiation surface is formed to have a curved surface.

Note that the upper and lower plates 201 and 202 of the diaphragm 20 are made of foam, unlike the honeycomb type, so they may or may not be present, or may be painted.

As mentioned above, according to the speaker device of the present invention, a foam that is easy to mold and whose hardness can be freely adjusted is used for the flat diaphragm, and the thickness of the diaphragm increases from the edges toward the center. This not only improves frequency characteristics by preventing resonance in the diaphragm itself, but also because the diaphragm is installed at an angle (not horizontally) to the edges, so the corners with the edges are soft, so the damping effect It is possible to prevent sound deterioration, and since the radiation surface is a curved surface, the radiation is emitted along the curved surface, which has advantages such as expanding the directivity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a flat speaker device using a conventional honeycomb diaphragm, and FIG. 2 is a sectional view showing an embodiment of the present invention. 5...Magnetic circuit, 7...Bobbin, 10
...Etsuji, 20...Vibration plate.

Claims (1)

[Scope of utility model registration request] In a speaker device having a flat diaphragm that is vibrably supported by a voice coil housed in a magnetic gap in a magnetic circuit, the flat diaphragm is formed of a foam, and the central part is gradually expanded from the outside. A speaker device characterized in that it is thick and has a convex shape at least on the radiation surface side.