JPH04999

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DESCRIPTION JPH04999
[0001]
The present invention relates to a dome-shaped speaker having a high frequency characteristic in
a high region in a speaker having a dome-shaped diaphragm in which a ceramic layer is formed
on the front or back surface of a light metal TRIM. (Prior Art) FIG. 5 shows a dome-shaped
speaker having a diaphragm (1) formed in a dome shape, in which (2) is a magnetic circuit and
this magnetic circuit (2) is a center ball Inverted T-shaped yoke (3) having 3a), ring-shaped
magnet (4) provided on the outer periphery of the yoke (3), and ring-shaped provided on the
upper part of the magnet (4) The inner peripheral surface of the plate (5) is separated from and
opposed to the outer peripheral surface of the center ball (3a) to form a magnetic gap. (6) is a
cylindrical voice coil hinge having on its outer periphery a voice coil (7) vibratably provided in
the magnetic gap portion, which is coupled to the diaphragm (1). The diaphragm (1) comprises a
dome-shaped diaphragm dome portion (1a) and a diaphragm dome outer peripheral portion (1b)
integrally formed on the outer periphery thereof. The outer end of the diaphragm outer
peripheral portion (lb) is a plate (5) The diaphragm ring (9) provided on the backing (8) and the
frame 0 (D) provided on the top of the diaphragm ring (9) are supported. The frame 0ω and the
diaphragm ring (9) are fixed to the plate (5) by the attachment screw 00, and the terminals
provided on the outer peripheral portion of the diaphragm ring (7) The vibration of the voice coil
(7) provided on the coil bobbin (6) is transmitted to the diaphragm (1) and vibrates to emit a
sound wave. It is well known that as the diaphragm material for high-pitched sound reproduction
of such a configuration, one having a large E / ρ is ideal. As this material, Be or Ti is subjected to
a chiselization or carbonization treatment Although there are things, etc., there is a disadvantage
that the processability is bad (and also expensive). Therefore, a light metal with good formability
and low cost, such as AE substrate, is used as the diaphragm material, and a ceramic layer (IC)
having a large specific elastic modulus is coated on the surface of the diaphragm dome portion
(1a) by various means. Various prior art techniques have been developed that are designed to
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(Problem to be Solved by the Invention) However, in the diaphragm (1) having such a
configuration, the vibration transmitted from the voice coil (7) to the voice coil bobbin (6) and
the diaphragm (]) during the vibration is Reflected from the top of the dome to form a node near
the outer periphery, the top and outer periphery are in antiphase, and as shown by a break 1 b in
FIG. Have the problem of adversely affecting
The present invention has been proposed in view of the above, and the purpose of the present
invention is the vibration of the type in which the diaphragm material is made of a light metal
thin film, which is shaped like a dome and the ceramic layer is formed on the surface. It is an
object of the present invention to provide a dome-shaped speaker with excellent sound quality by
removing the sharp peak of the high-resonance frequency in one provided with a plate. (Means
for Solving the Problems) The present invention relates to a dome-shaped speaker including a
diaphragm made of a light metal thin film as a base material and having a ceramic layer formed
on the front or back of a dome-shaped diaphragm dome. The above object is achieved by
providing a portion without the ceramic layer on the outer periphery of the diaphragm dome
portion of the diaphragm, or forming a ceramic layer on the outer peripheral portion of the
diaphragm of the diaphragm. (Operation) The present invention is configured as described above,
and the stiffness of the top having the ceramic layer is different from the stiffness of the outer
periphery where the ceramic layer is not partially formed. It is difficult to disperse the resonance,
so that sharp peaks do not occur in the high region. Embodiment 1 FIGS. 1 (a) and 1 (b) show a
first embodiment of the present invention. A light metal thin film such as Affi is used as a
material of the diaphragm 00. 1a) and a diaphragm outer peripheral portion (11b), and a ceramic
layer (llc) is formed, for example, by coating on the surface or the back surface (the surface in the
illustrated example) of the diaphragm dome portion (11a) However, in this case, it is
characterized in that, for example, an approximately crescent-shaped uncoated portion (11 (1) is
formed in left-right symmetry on the outer peripheral portion of the diaphragm dome portion
(lla). Note that (6) is a voice coil bobbin, (7) is a voice coil, and the configuration of the other
speakers is basically the same as that shown in FIG. 5, so their illustration and detailed
description will be omitted. Thus, the uncoated portion (11d) is composed of a metal thin film of
a substrate and this portion has a large difference from the stiffness of the portion coated with
the ceraminic layer (11c), and the stiffness of the outer peripheral portion is ceramic The
stiffness of the top portion coated with the layer (11c) is uneven due to the uncoated portion.
Therefore, the vibration is transmitted to the voice coil (7), the voice coil bobbin (6), and the
diaphragm (11), and it is difficult to form a node on the outer periphery against the reflection of
the vibration from the top. As shown by the solid line a in FIG. 4, sharp peaks do not occur.
This also contributes to the different apparent distances from the top to the periphery.
(Embodiment 2) FIG. 2 shows a second embodiment of the present invention. In this embodiment,
the uncoated portion (11d) of the outer peripheral portion is positioned at three equally divided
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positions of approximately 120 "" centering on the top portion. And the uncoated portion (11d) is
substantially arc-shaped, and the uncoated portion (lid) is increased compared to the first
embodiment. Thus, the number of positions and the shape of the uncoated portion (lid) are
appropriately designed in accordance with the diameter of the diaphragm and the like so as to
obtain an optimum frequency characteristic. (Third Embodiment) FIG. 3 shows a third
embodiment of the present invention. In this embodiment, in addition to the second embodiment,
an appropriate position of the diaphragm outer peripheral portion (llb) of the diaphragm (11), for
example, a ceramic layer (lie) radially approximately in the middle between uncoated portions
(lld) and (lid). It has the structural feature in having formed. Thus, the stiffness of the diaphragm
outer peripheral portion (llb) is partially adjusted to adjust the antiresonance at the outer
peripheral portion. (Effects of the Invention) As described above, according to the present
invention, a dome-shaped speaker comprising a diaphragm made of a light metal thin film as a
base material and having a ceramic layer formed on the front or back of the dome shaped
diaphragm dome. Further, since the ceramic layer is formed on the diaphragm outer peripheral
portion of the diaphragm in addition to the portion without the ceramic layer provided on the
outer periphery of the diaphragm dome portion of the diaphragm, the sharp peak of the high
region resonance frequency It can be removed and a good reproduced sound can be obtained.
[0002]
Brief description of the drawings
[0003]
FIG. 1 (a) is a side sectional view of the first embodiment of the present invention, FIG. 2 is a plan
view of the same, FIG. 2 is a plan view of a second embodiment of the present invention, and FIG.
A plan view of the third embodiment, FIG. 4 shows a frequency characteristic chart comparing
the present invention with the prior art, and FIG. 5 shows a side sectional view of a conventional
dome-shaped loudspeaker in the prior art.
11 · · 11a · 11b · 11c · 11d · lie · Diaphragm dome portion Diaplum outer peripheral portion
ceramic layer uncoated portion ceramic layer
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