JP2008092032A - Speaker and electronic device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain thinning and to increase sound output, relating to a speaker of a thin type and electronic equipment using it. <P>SOLUTION: The speaker comprises: a case 4A; first and second planar magnets 12 and 7 arranged in a horizontal direction or a roughly horizontal direction through a magnetic gap inside the case 4A; a voice coil 10 freely movably arranged in the magnetic gap; and a diaphragm 9 connected to the voice coil 10. The first planar magnet 12 forms a magnetic pole at the plate end, the second planar magnet 7 forms a magnetic pole at both ends of the thickness direction, and a magnetic flux is roughly orthogonal to the part of the voice coil 10 at the part of the voice coil 10 in the magnetic gap. Also, on the non-facing part of the first and second planar magnets 12 and 7, which is the part facing the voice coil 10, a magnetic flux conductor 12A connected in a magnetic flux conducting manner to the magnetic pole of either one of the first and second planar magnets 12 and 7 is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thin type speaker and an electronic apparatus using the same.

  Since electronic devices such as portable devices are required to be thin, a speaker built in the main body is also required to be thin.

In order to reduce the thickness of the speaker, it is natural to reduce the size of the magnet for forming the magnetic circuit. However, if the magnet is made smaller, the magnetic force becomes smaller, resulting in sound output. Since it becomes small, the magnet cannot actually be made very small (for example, such a conventional technique is described in Patent Document 1 below).
JP 2005-51283 A

  As described above, the type of speaker built into an electronic device such as a portable device has been conventionally reduced in thickness. However, in order to avoid a decrease in audio output, the magnet cannot actually be made too small. As a result, there has been a problem that thinning which can be satisfactorily satisfied has not been achieved.

  Therefore, the present invention aims to reduce the thickness and to suppress a decrease in audio output.

  In order to achieve this object, the present invention provides a case, first and second plate magnets arranged in a horizontal direction or a substantially horizontal direction via a magnetic gap in the case, and the magnetic gap. A voice coil arranged movably and a diaphragm coupled to the voice coil are provided. The first plate magnet forms a magnetic pole at the plate end, and the second plate magnet has a thickness thereof. Magnetic poles are formed at both ends in the direction, and in the voice coil portion in the magnetic gap, the magnetic flux is substantially orthogonal to the voice coil portion, and the non-opposing portions of the first and second plate magnets Thus, the portion facing the voice coil is provided with a magnetic flux conductor that is magnetically conductively connected to one of the magnetic poles of the first and second plate magnets.

  As described above, the present invention includes the first and second plate magnets arranged in the horizontal direction or the substantially horizontal direction through the magnetic gap, the voice coil movably arranged in the magnetic gap, and the voice coil. The first plate magnet has a magnetic pole formed at its plate end, and the second plate magnet has a magnetic pole formed at both ends in the thickness direction, and the magnetic gap In the voice coil portion, the magnetic flux is substantially perpendicular to the voice coil portion, and the speaker is arranged in the horizontal direction or the substantially horizontal direction of the magnetic gap via the magnetic gap. In addition, since the first and second plate magnets are arranged on both sides of the magnetic gap, it is possible to increase the magnetic force and increase the sound output.

  In addition, the non-opposing portion of the first and second plate magnets and the portion facing the voice coil are magnetically connected to one of the magnetic poles of the first and second plate magnets. Since the magnetic flux conductor is provided, the magnetic flux can be passed through the voice coil through the magnetic flux conductor even at the non-opposing portions of the first and second plate magnets. It is possible to suppress a decrease in audio output when the operation is performed.

  Hereinafter, an embodiment of the present invention will be described using a cellular phone as an example of an electronic device with reference to the accompanying drawings.

  In FIG. 1, reference numeral 1 denotes a main body, and a lid 2 is coupled to the main body 1 so as to be freely opened and closed. When viewed from the back side in FIG. 1, the main body 1 is provided with operation buttons (not shown), and the lid 2 is provided with a liquid crystal display (not shown), as in a general mobile phone. It has been.

  Further, two covers 3 are provided on the outer surface side of the main body 1 as shown in FIG. 1, and the speaker 4 shown in FIGS. 2 and 3 is mounted in the main body 1 on the back side of these covers 3. .

  As shown in FIG. 3, the speaker 4 is formed of a surface-side plate 5 made of stainless steel 301 which is a non-magnetic material, a plate 6 made of cold-rolled steel plate which is a magnetic material, and the following frame 13. In the case 4A, the second plate magnet 7 made of neodymium in order from the plate 6 side to the plate 5, the ring 8 formed of a cold-rolled steel plate as a magnetic material, and the diaphragm formed of a PEI resin film 9, a voice coil 10 formed of copper wire, a ring 11 formed of a cold-rolled steel plate as a magnetic material, and two neodymium first plate magnets 12 are sequentially arranged. .

  A front-side sound emission hole 5A is provided on the surface of the plate 5, and the outer peripheral portion is covered with the resin frame 13 as shown in FIGS.

  As shown in FIGS. 3, 5, and 6, the plate 6 has an oval shape, and the upper surface of the rectangular fixing portion 6 </ b> A in the longitudinal central axis portion has a rectangular plate-shaped magnet 7 below it. The plane is fixed by an adhesive (not shown), and rectangular openings 6B are formed on both sides of the fixed portion 6A.

  A ring 8 is fixed to the outer peripheral portion of the plate 6 so that magnetic flux can pass therethrough.

  Further, the outer periphery of the diaphragm 9 is placed on the ring 8, and the ring 11 is placed on the outer periphery of the diaphragm 9.

  Further, the upper surface of the two plate magnets 12 is fixed to the lower surface of the plate 5 facing the opening 6B of the plate 6 with an adhesive (not shown) above the diaphragm 9. Each of the outer peripheral surfaces of the two plate magnets 12 has a part of an adhesive (not shown) for bonding the upper surfaces of the two plate magnets 12 to the lower surface portion of the plate 5. By entering between the outer peripheral surface of each of the magnets 12 and the inner peripheral surface of the frame 13, it is also fixed to the frame 13 portion.

  In addition, an elliptical voice coil 10 is fixed to a portion of the upper surface of the diaphragm 9 corresponding to the outer periphery of the plate magnet 7 as shown in FIG.

  In the state configured as described above, the two plate magnets 12 made of neodymium are magnetized such that the inner end in the longitudinal direction is an N pole and the outer end is an S pole as shown in FIG. In addition, a magnetic flux conductor 12A that is ring-shaped and covers the outer periphery of the voice coil 10 in a non-contact state is provided on the inner surface side (that is, the N pole side) of the two plate magnets 12. The magnetic flux conductor 12A is formed of a cold-rolled steel plate that is a magnetic material, and is connected to the magnetic flux conductor 12A in a magnetic flux manner so that the magnetic flux from the N pole of the plate magnet 12 enters smoothly. Has been.

  Further, as shown in FIG. 7, the neodymium plate magnet 7 is magnetized such that the surface side in the thickness direction is an S pole and the lower surface side in the thickness direction is an N pole.

  As a result, as shown in FIGS. 4 and 7, the magnetic flux emitted from the N pole inside each of the two plate magnets 12 made of neodymium (in FIG. 4, one plate magnet is used in order to avoid the complexity of the drawing. Most of the magnetic flux from 12 is shown in the figure. Most of the voice coil 10 is moved substantially inward toward the upper surface S pole of the plate magnet 7 via the magnetic flux conductor 12A. Cross in an orthogonal state and then enter the south pole of the upper surface of the plate magnet 7 (note that the plate magnet 12 and the plate magnet 7 are arranged in a horizontal or substantially horizontal state. As shown in FIG. 6, the substantially horizontal state is an oblique state in which the thickness directions of the plate magnet 12 and the plate magnet 7 are partially overlapped in the horizontal direction, and the both are not partially overlapped in the thickness direction in the horizontal direction. Including the oblique state where the 0 substantially is important to proceed as perpendicular to, the horizontal state in that respect in which slight width is set.).

  Thereafter, the magnetic flux emitted from the N pole on the lower surface of the plate-shaped magnet 7 travels through the rectangular fixed portion 6A of the plate 6, enters the ring 11 after passing through the outer periphery of the ring 8 and the diaphragm 9, and then enters this ring. For example, after a quarter of a round travels 11, it enters the outer peripheral S pole of the plate magnet 12 fixed to the inner periphery of the ring 11 as shown in FIG. 6.

  The flow of the magnetic flux directly becomes a magnetic circuit, and a magnetic gap is formed between the inner N pole of the plate magnet 12 and the upper surface S pole of the plate magnet 7 in the magnetic circuit. A driving force is applied, whereby vibration is transmitted to the diaphragm 9 to which the voice coil 10 is fixed, and sound output is generated.

  Here, the progression of the magnetic flux in the magnetic gap will be described again.

  The magnetic flux emitted from the N pole inside each of the plate magnets 12 shown in FIGS. 4 and 7 travels substantially horizontally inward in the magnetic gap via the magnetic flux conductor 12A, and is substantially orthogonal to the voice coil 10. Crossing in a state is very important for increasing the electromagnetic field driving force, and is a major feature in the present embodiment.

  In the present embodiment, the reason why the magnetic flux travels substantially inward in the magnetic gap and crosses the voice coil 10 in a substantially orthogonal state will be considered.

  Generally speaking, the magnetic flux emitted from the N pole of the plate magnet 12 through the magnetic flux conductor 12A tends to travel obliquely to the S pole on the upper surface of the plate magnet 7 with a short distance (this In this case, the magnetic flux crosses the voice coil 10 at a slight angle.) By receiving the repulsion of the N pole on the lower surface of the plate magnet 7, it is actually lifted by the repulsive force. In FIG. 7, it is considered that the magnetic flux travels substantially inward in the magnetic gap as shown in FIG.

  In the present embodiment, since the plate magnets 12 and 7 are provided on both sides of the magnetic gap as described above, the so-called magnetic force is increased, and as a result, the sound output by the diaphragm 9 can be increased.

  In addition, the plate magnets 12 and 7 for increasing the magnetic force are literally plate-like and themselves are thin, and they are installed in a substantially parallel state including an oblique state. It can be thin.

  In the present embodiment, as described above, the magnetic flux conductor 12A is provided on the inner surface side (that is, the N pole side) of the two plate magnets 12 in a ring shape and covers the outer periphery of the voice coil 10 in a non-contact state. Therefore, the voice output can be increased.

  That is, since the magnetic flux conductor 12A covers the outer periphery on the short side of the voice coil 10 where the plate magnets 12 and 7 do not face each other, the magnetic flux entering the magnetic flux conductor 12A from the N pole of the plate magnet 12 is not affected. An inner portion travels through the magnetic flux conductor 12A, travels to the short side of the voice coil 10, passes through the short side, and travels to the upper surface S pole of the plate magnet 7. As a result, a magnetic driving force can be obtained even on the short side of the voice coil 10, thereby increasing the sound output.

  Next, the upper surface of the two plate magnets 12 having a large surface area is fixed to the lower surface portion of the plate 5 with an adhesive (not shown), so that the strength against vibration and impact applied to the case 4A is strong. Become.

  Further, since the plate 5 is made of a non-magnetic material, even if the entire upper surface of the plate magnet 12 having both ends of the N pole and the S pole is covered, no magnetic short circuit is caused.

  Further, since the lower surface of the plate magnet 7 having a large surface area is fixed to the upper surface portion of the magnetic plate 6 with an adhesive (not shown), the strength against vibration and impact applied to the case 4A is increased. Further, since the plate 6 is made of a magnetic material, even if the entire lower surface of the plate magnet 7 whose upper and lower ends are S and N poles is covered, the formation of the magnetic circuit shown in FIG. 4 is not hindered.

  Further, in the present embodiment, since the rear sound emitting hole 13A is provided in the outer peripheral portion of the plate magnet 7 of the case 4A, specifically, the frame 13 portion, this vibration is caused by the vibration of the diaphragm 9. Air from the back side of the plate 9 is discharged out of the frame 13 through the back sound emitting hole 13A, and this leads to suppression of an increase in vibration load accompanying the reduction in thickness.

  Further, by providing the rear sound emitting hole 13A, the frame 6 can be placed in contact with the installation portion of the electronic device, which further contributes to the reduction in thickness.

  As is apparent from FIGS. 6 and 7, the diaphragm 9 covers the front side of the plate magnet 7 and the outer periphery extends to the back side of the plate magnet 12 through a magnetic gap. However, in this extended portion, that is, in the outer peripheral direction of the plate-like magnet 7, it protrudes to the front side of the case 4 </ b> A, thereby ensuring a ventilation path to the rear sound emitting hole 13 </ b> A. ing.

  As described above, the present invention includes the first and second plate magnets arranged in the horizontal direction or the substantially horizontal direction through the magnetic gap, the voice coil movably arranged in the magnetic gap, and the voice coil. The first plate magnet has a magnetic pole formed at its plate end, and the second plate magnet has a magnetic pole formed at both ends in the thickness direction, and the magnetic gap In the voice coil portion, the magnetic flux is substantially perpendicular to the voice coil portion, and the speaker is arranged in the horizontal direction or the substantially horizontal direction of the magnetic gap via the magnetic gap. In addition, since the first and second plate magnets are arranged on both sides of the magnetic gap, it is possible to increase the magnetic force and increase the sound output.

  In addition, the non-opposing portion of the first and second plate magnets and the portion facing the voice coil are magnetically connected to one of the magnetic poles of the first and second plate magnets. Since the magnetic flux conductor is provided, the magnetic flux can be passed through the voice coil through the magnetic flux conductor even at the non-opposing portions of the first and second plate magnets. It is possible to suppress a decrease in audio output when the operation is performed.

  As a result, it becomes very easy to use for portable devices such as mobile phones.

The perspective view which applied one Embodiment of this invention to the mobile telephone The perspective view which applied one Embodiment of this invention to the mobile telephone Exploded perspective view of the speaker Exploded perspective view of the speaker Sectional view of the speaker cut in the longitudinal direction Sectional view of the speaker cut in the short direction 6 is an enlarged cross-sectional view of a portion A in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 4 Speaker 4A Case 7 2nd plate-shaped magnet 12 1st plate-shaped magnet 13A Back surface sound emission hole

Claims (5)

A case, first and second plate magnets disposed in a horizontal or substantially horizontal direction via a magnetic gap in the case, a voice coil movably disposed in the magnetic gap, and the voice coil The first plate magnet has a magnetic pole formed at its plate end, and the second plate magnet has a magnetic pole formed at both ends in the thickness direction, and the magnetic gap In the voice coil portion, the magnetic flux is substantially perpendicular to the voice coil portion, and the non-opposing portion of the first and second plate-like magnets, A speaker provided with a magnetic flux conductor that is magnetically conductively connected to one of the magnetic poles of the first and second plate magnets. The rectangular first plate magnets are arranged on both sides in the longitudinal direction of the rectangular second plate magnet via the magnetic gaps so that the longitudinal directions thereof are substantially opposed to each other, and the voice coil has a substantially planar shape. The speaker according to claim 1, wherein the speaker has an oval shape, and the long sides on both sides of the substantially oval voice coil are arranged in the magnetic gap on both sides of the rectangular second plate magnet. The said 1st plate-shaped magnet is surface-fixed to the front-plate part of the case formed with the nonmagnetic material, The 2nd plate-shaped magnet was surface-fixed to the back plate part of the case. Speaker. The speaker according to claim 2, wherein a magnetic flux conductor that is magnetically conductively connected to the magnetic pole of the first plate magnet is provided outside the short side of the voice coil. The electronic device which incorporated the speaker as described in any one of Claim 1 to 4 in the main body.

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