JP4403941B2 - Speaker - Google Patents

Description

  The present invention relates to a speaker used for various kinds of audio equipment, electronic equipment, mobile phones and the like.

  In recent years, with regard to small electronic devices and mobile phones, while further miniaturization has progressed, higher sound quality has also been demanded, and the speakers mounted on such devices are similarly thinner, There is a need for slimming and higher sound quality.

  FIG. 10 is a cross-sectional view showing the configuration of a conventional slim speaker of this type, and FIG. 11 is a plan view showing a voice coil used in the speaker, which the applicant has proposed as a slim speaker. Is.

  10 and 11, reference numeral 20 denotes a first magnet, and reference numeral 21 denotes a first yoke coupled around the first magnet 20, thereby providing a first magnetic circuit having a first magnetic gap 20a. 22 is configured. Reference numeral 23 denotes a first frame coupled around the first yoke 21, and reference numeral 23 a denotes an air hole provided in the first frame 23. Reference numeral 24 denotes a diaphragm, and 24 a denotes an edge provided on the diaphragm 24, and the periphery of the diaphragm 24 is coupled to the periphery of the first frame 23. A voice coil 25 is coupled to the diaphragm 24. The voice coil 25 is wound in a shape corresponding to the first magnetic gap 20a for a plurality of turns. Reference numeral 25a denotes a start end (or a rear end not shown) of the voice coil 25, which is soldered to a terminal (not shown) coupled to the first (or second) frame 23 via a lead wire (not shown). It is comprised so that it may connect by doing.

  Reference numeral 26 denotes a second magnetic circuit disposed symmetrically with the first magnetic circuit 22 so as to sandwich the diaphragm 24. Similarly to the first magnetic circuit 22, the second magnetic circuit 26 is arranged at the center of the second yoke 27. A second magnetic gap 28 a is provided by coupling the two magnets 28, and the second magnetic circuit 26 is coupled to the center of the second frame 29. Reference numeral 29 a denotes air holes provided in the second frame 29.

  In the conventional speaker configured as described above, the first magnet 20 and the second magnet 28 are magnetized in the thickness direction and in the direction in which each repels, and the first magnetic gap 20a and the second magnet 28 are magnetized. By arranging the voice coil 25 at a position where the leakage magnetic field generated from each gap 28a can be utilized to the maximum, the voice coil 25 is caused to swing up and down by inputting a voice signal to the voice coil 25. The combined diaphragm 24 was configured to perform sound reproduction with amplitude.

For example, Patent Document 1 is known as prior art document information related to the invention of this application.
Japanese Patent Application Laid-Open No. 2004-88739

  However, in the above conventional speaker, the first (or second) magnetic circuit 22 and the voice coil 25 are rectangular in shape (which may be any of an elliptical shape, an oval shape, or a track shape). The plate 24 is inevitably formed in the same shape, and as a result, there is an inherent problem that the elasticity in the central portion in the longitudinal direction of the vibration plate 24 is smaller than that at both ends.

  Therefore, when the sound signal is input to the voice coil 25 and the diaphragm 24 is amplified by the magnetic field generated from the first (or second) magnetic gap 20a to perform sound reproduction, the entire diaphragm 24 is uniform. Instead of amplitude with a simple stroke, a phenomenon occurs in which only the central part in the longitudinal direction, which is less elastic than both ends, is more than necessary (generally called taiko movement). In addition to deteriorating the characteristics, it has a fatal problem that high input resistance cannot be achieved because a predetermined input cannot be applied.

  The present invention solves such a conventional problem, and even when a diaphragm having a rectangular shape or the like is used, the entire diaphragm has a uniform amplitude and can realize excellent performance and high input resistance. Is intended to provide.

  In order to solve the above problems, the present invention provides a magnetic circuit having a magnetic gap formed by coupling a magnet and a yoke, a frame in which the magnetic circuit is coupled, and a magnetic gap above the magnetic gap in a noncontact manner. A voice coil that is closely arranged in a state and a diaphragm in which the voice coil is coupled and an outer peripheral portion is coupled to the frame. The shape of the diaphragm, the voice coil, and the magnetic gap are rectangular, elliptical, and oval. The conversion efficiency adjusting means for reducing the efficiency of converting the current applied to the voice coil into the amplitude motion by the magnetic field generated from the magnetic gap in the track type speaker is provided in the longitudinal direction of the magnetic gap and / or the voice coil. The configuration is provided at the center of the direction.

  As described above, the speaker according to the present invention has a conversion efficiency for reducing the efficiency of converting the current applied to the voice coil into the amplitude motion by the magnetic field generated from the magnetic gap in the speaker using the rectangular diaphragm or the like. With the configuration in which the adjusting means is provided at the central portion in the longitudinal direction of the magnetic gap and / or the voice coil, so-called drum movement in which only the central portion of the diaphragm is more than necessary as in the conventional case can be suppressed. As a result, the entire diaphragm is uniformly oscillated, thereby obtaining a special effect that excellent performance and high input resistance can be realized at the same time.

(Embodiment 1)
In the following, the first and third aspects of the present invention will be described with reference to the first embodiment.

  FIG. 1 is a cross-sectional view showing a configuration of a speaker according to Embodiment 1 of the present invention. FIGS. 2A and 2B are a perspective view and a front view showing the configuration of the magnetic circuit. 2, 1 is a rectangular first yoke made of a magnetic metal material, and 1 a is a recess provided by partially lowering the substantially central portion of the longitudinal wall portion of the first yoke 1. . Reference numeral 2 denotes a rectangular first magnet, which is inserted into and coupled to the first yoke 1 to form a first magnetic circuit, and the inner wall surface of the first yoke 1 and the first magnet 1 A first magnetic gap 2 a having a rectangular uniform gap is formed between the magnet 2 and the outer peripheral surface.

  Reference numeral 3 denotes a first frame coupled around the first yoke 1 constituting the first magnetic circuit, which is formed of a resin or a metal material. Reference numeral 4 denotes a voice coil. The voice coil 4 has a rectangular shape in which a coil having a desired pattern is formed by copper plating on the front surface of the polyimide substrate 4a (which is also formed on the back surface in the present embodiment). The coil that is formed in a wound state and wound in a rectangular shape is formed in substantially the same shape as the first magnetic gap 2a provided in the first magnetic circuit.

  Reference numeral 5 denotes a rectangular diaphragm made of resin. The diaphragm 5 has a flat plate-like main body portion 5a at the center, an edge portion 5b at the peripheral edge of the main body portion 5a, and a flat plate at the peripheral edge of the edge portion 5b. The affixed portion is formed in a single structure.

  6 is a rectangular second yoke made of a magnetic metal material, and 6a is a recess (not shown) provided by partially lowering the substantially central portion of the longitudinal wall of the second yoke 6. It is. Reference numeral 7 denotes a rectangular second magnet, which is fitted into and coupled to the second yoke 6 to constitute a second magnetic circuit, and the inner wall surface of the second yoke 6 and the second magnet. A second magnetic gap 7 a having a rectangular uniform gap is formed between the outer peripheral surface of the magnet 7.

  Reference numeral 8 denotes a second frame coupled around the second yoke 6 constituting the second magnetic circuit, and is formed of a resin or a metal material. The second frame 8 and the second frame Are arranged so as to face each other with the diaphragm 5 interposed therebetween, so that the peripheral portion of the diaphragm 5 is sandwiched between the periphery of the first frame 3 and the periphery of the second frame 8. The voice coil 4 coupled to the diaphragm 5 is coupled to the diaphragm 5 so as to be disposed at a substantially intermediate position between the first magnetic gap 2a and the second magnetic gap 7a.

  The speaker according to the present embodiment configured as described above has a magnetic circuit as a conversion efficiency adjusting means for reducing the efficiency of converting the current applied to the voice coil 4 into the amplitude motion by the magnetic field generated from the magnetic gap 2a. The configuration in which the height of the wall portion of the yoke 1 to be configured is partially lowered reduces the magnetic force generated from the magnetic gap 2a in the portion where the wall portion is lowered, so that both ends of the diaphragm 5 at the central portion in the longitudinal direction. Due to the inherent problem that the elasticity is smaller than that of the section, the entire diaphragm 5 does not swing with a uniform stroke, and the entire diaphragm 5 is suppressed by suppressing the occurrence of a drum movement in which only the central portion in the longitudinal direction swings more than necessary Thus, it is possible to make the amplitude of the signal uniform, thereby obtaining a special effect that excellent performance and high input resistance can be realized at the same time.

  3A and 3B are a perspective view and a front view showing another example of the magnetic circuit of the speaker according to the present embodiment, in which 9 is a yoke and 9a is a longitudinal direction of the yoke 9. The concave portion 9a is formed by lowering the substantially central portion of the wall portion in the direction. The concave portion 9a is formed by dropping at a sharper angle than the concave portion 1a of the yoke 1 shown in FIG. In this way, when forming the concave portion, it may be formed in any shape such as being dropped with a gentle taper, dropped vertically, or curved on the R surface.

  FIG. 4 is a plan view showing another example of the magnetic circuit of the speaker according to the present embodiment. In FIG. 4, 10 shows a yoke, 11 shows a magnet, and this magnet 11 has a substantially central portion in the longitudinal direction. A concave portion 11a that is partially narrowed is provided, and only the magnetic gap in the concave portion 11a is partially widened. Even with such a configuration, the same effect as that of the magnetic circuit shown in FIGS. 2A and 2B or FIGS. 3A and 3B can be obtained.

(Embodiment 2)
The second aspect of the present invention will be described below with reference to the second embodiment.

  FIG. 5 is a plan view showing the configuration of the voice coil of the speaker according to the second embodiment of the present invention. In FIG. 5, 12 indicates a voice coil, and this voice coil 12 is the surface of the substrate 12a made of polyimide. In the embodiment, the coil of a desired pattern is formed in a rectangular shape by copper plating on the back surface in the same manner, and the coil in the substantially central portion in the longitudinal direction of the rectangular shape is It is formed in a shape shifted in position so as to partially bulge outward.

  FIGS. 6A and 6B are a half sectional view showing a configuration of a speaker using the voice coil, and a characteristic diagram showing a distribution state of a magnetic field generated from the magnetic circuit of the speaker. However, the magnetic field generated from the magnetic gap 2a is strongest in the magnetic gap 2a and becomes weaker as the distance from the magnetic gap 2a increases.

  Therefore, as in the voice coil 12 of the present embodiment, the position is shifted from the magnetic gap 2a by shifting the position so that the substantially central portion in the longitudinal direction of the coil wound in a rectangular shape partially bulges outward. The portion where the magnetic field is weak will be used.

  The speaker according to the present embodiment configured as described above has a rectangular shape as a conversion efficiency adjusting means for reducing the efficiency of converting the current applied to the voice coil 12 into the amplitude motion by the magnetic field generated from the magnetic gap 2a. Since the position is shifted so that the substantially central portion in the longitudinal direction of the wound coil partially bulges outward, the magnetic force from the magnetic gap 2a received by the shifted portion is weakened. Due to the inherent problem that the elasticity of the central portion in the longitudinal direction is smaller than that at both ends, the entire diaphragm 5 does not vibrate with a uniform stroke, and the drum motion in which only the central portion in the longitudinal direction swings more than necessary is generated. And the vibration plate 5 as a whole can be uniformly oscillated, so that excellent performance and high input resistance can be realized at the same time. In which the effect can be obtained.

  FIGS. 7A and 7B are shown for easier understanding of the operational effects of the speaker according to the present embodiment. In FIG. 7, the coil of the voice coil 4 is arranged at the center of the magnetic gap 2a. In this configuration (similar to the first embodiment and the conventional example), the magnetic field generated from the magnetic gap 2a is used most efficiently. Therefore, in this way, the diaphragm 5 as a whole does not vibrate with a uniform stroke due to the inherent problem that the elasticity in the central portion of the diaphragm 5 in the longitudinal direction is smaller than both ends, and only the central portion in the longitudinal direction This leads to the occurrence of taiko movement that has more amplitude than necessary.

  8 and 9 are plan views showing other examples of the voice coil of the loudspeaker according to the present embodiment. In contrast to the voice coil 12 shown in FIG. 5, the coil is wound in a rectangular shape. The voice coils 13 and 14 are configured by partially shifting the position of the substantially central portion in the longitudinal direction inward, and the operation and effects thereof are the same as those of the voice coil 12 described above. Is omitted.

  The speaker according to the present invention has a feature that even when a diaphragm having a rectangular shape or the like is used, the entire diaphragm has a uniform amplitude and can realize excellent performance and high input resistance. It is useful for electronic devices or mobile phones.

Sectional drawing which showed the structure of the speaker by Embodiment 1 of this invention (A) The perspective view which showed the structure of the magnetic circuit, (b) The front view (A) The perspective view which showed the other example of the magnetic circuit, (b) The front view Plan view showing another example of the magnetic circuit The top view which showed the structure of the voice coil of the speaker by Embodiment 2 of this invention (A) Half sectional view showing a configuration of a speaker using the voice coil, (b) Characteristic diagram showing magnetic field distribution of the magnetic circuit (A) Half sectional view of the speaker shown for comparison with FIG. 6, (b) Characteristic diagram showing magnetic field distribution of the magnetic circuit Plan view showing another example of the voice coil Plan view showing another example of the voice coil Sectional view showing the configuration of a conventional slim speaker Plan view showing voice coil used for the speaker

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st yoke 1a, 9a, 11a Recessed part 2 1st magnet 2a 1st magnetic gap 3 1st frame 4, 12, 13, 14 Voice coil 4a, 12a, 13a, 14a Base material 5 Diaphragm 5a Main body Part 5b edge part 6 second yoke 7 second magnet 7a second magnetic gap 8 second frame 9, 10 yoke

Claims (5)

A magnetic circuit having a magnetic gap formed by coupling a magnet and a yoke; a frame in which the magnetic circuit is coupled; a voice coil disposed close to the magnetic gap in a non-contact manner; In a loudspeaker in which a voice coil is coupled and an outer peripheral portion is composed of a diaphragm coupled to the frame, and the diaphragm and the voice coil and the magnetic gap have a rectangular, elliptical, oval, or track shape. A speaker in which conversion efficiency adjusting means for reducing the efficiency of converting current applied to a voice coil into amplitude motion by a magnetic field generated from the magnetic gap is provided in the magnetic gap and / or the central portion in the longitudinal direction of the voice coil. The speaker according to claim 1, wherein the height of the wall portion of the yoke constituting the magnetic circuit is partially reduced as the conversion efficiency adjusting means. The speaker according to claim 1, wherein as the conversion efficiency adjusting means, the gap width of the magnetic gap constituting the magnetic circuit is partially widened. The speaker according to claim 1, wherein the voice coil is arranged so as to be shifted from a position where the magnetic field generated from the magnetic gap is maximized as the conversion efficiency adjusting means. The speaker according to claim 1, wherein a magnetic circuit having a magnetic gap and a frame coupled with the magnetic circuit are arranged symmetrically facing each other through a diaphragm.

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