JP2003305409A - Thin electromagnetic acoustic transducer for mobile communication apparatus and method for using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent attenuation of vibrations with a thin type by exercising ingenuity in the shape of an exciting coil and the arrangement and configuration of a magnetism generating body. <P>SOLUTION: The electromagnetic acoustic transducer is provided with a thin sounding plate (1) disposed within the magnetic field of a magnetism generating body and supported at its outer peripheral part by a portion of a housing (H) and the exciting coil (2) formed of printed wiring at this sounding plate and is provided with the magnetism generating body (4) disposed to face the sounding plate across a gap and a planar elastic body (6) placed on the magnetism generating body across a weight (4a). The outer peripheral part of the planar elastic body is supported at a base (3) which is a portion of the housing, by which the planar elastic body is supported overhead in the air to move vertically. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an electromagnetic acoustic transducer used as a notification means of a mobile communication device,
Particularly, it relates to a device suitable for an ultra-thin mobile communication device.

[0002]

2. Description of the Related Art In recent years, mobile communication technology has been developed more and more, and the weight and thickness of mobile devices have been accelerated. In response to this, in addition to the vibration motor as the notification means, recently, a notification means (magnetic buzzer) composed of an electromagnetic sounding body to which the technology of a linear motor is applied, or a silent function having a vibration function by inputting a low frequency signal Those equipped with notification means have become known. Such an electromagnetic acoustic transducer is generally shown in FIG.
There is something like. That is, a magnetic pole member J is fixed in the center of a resin case K, a cylindrical solenoid type excitation coil C is arranged around the magnetic pole member J, and a vertically magnetized field magnet M is arranged around the magnetic pole member J. A diaphragm D made of a thin permalloy having an armature member A fixedly opposed to J is attached to the case K and covered with a cover V.

Recently, in mobile communication devices, silent call means based on vibration has come to be frequently used due to the problem of noise of the notification means based on sound. As this vibration generating means, an eccentric weight is attached to the output shaft of a cylindrical DC motor, or a flat coreless vibration motor in which the rotor itself is eccentric is used. The motor is used because the amplitude is relatively large and the efficiency is high only by using the centrifugal force. By the way, recently, in place of such a vibration motor, there has been proposed one in which both sound and vibration are obtained by an electromagnetic converter as shown in FIG. 1 of Japanese Patent Application No. 3-44627. That is, a movable magnetic pole member is provided by supporting the magnetic pole member as described above at the center of a spring body, and a low-frequency, for example, 100 Hz full-wave or half-wave current is applied to an exciting coil arranged around the magnetic pole member to move the movable magnetic pole. The member is moved up and down in the figure to obtain vibration. Such an electromagnetic transducer is designed to generate a buzzer sound by vibrating a diaphragm to which an armature member is fixed by applying an alternating current having a relatively high frequency, for example, a current of 2 to 3 KHz to an exciting coil. At 2 to 3 KHz, the movable magnetic pole member does not function as a vibrating body. In this way, both sound generation and vibration functions can be obtained according to the cycle of the current applied to the exciting coil. Further, as disclosed in Japanese Patent Application Laid-Open No. 10-117472, the sounding body is made into a thin film, the cylindrical exciting coil arranged in this film is arranged in a magnetic circuit, and an electric signal is given to this cylindrical exciting coil to obtain a diameter. There is a device that generates sound and vibration under the influence of a field magnet arranged in a certain direction. However, in such a wound-type excitation coil, the coil itself vibrates, which causes a problem of disconnection of the terminal, which complicates the processing of the terminal.

[0004]

[Problems to be Solved by the Invention]
However, in the conventional electromagnetic acoustic transducer configured as described above, the exciting coil is a cylindrical solenoid and is a radial air gap type, as can be judged from the respective embodiments, so that the overall attitude is improved. Even if it is small, it will be thick at around 4-5 mm, which makes it difficult to use on the device side.
There is a problem that it is not convenient.

Therefore, the present invention solves the above-mentioned drawbacks by devising the shape of the exciting coil and the arrangement of the magnetic generators, and provides a thin electromagnetic acoustic transducer for mobile communication without the problem of disconnection. To do.

[0006]

In order to solve the above-mentioned problems, according to the invention as set forth in claim 1, a thin sounding plate arranged in a magnetic field of a magnetic generator and having an outer peripheral portion supported by a housing. In an electromagnetic acoustic transducer including an exciting coil arranged on the sounding plate and a housing supporting an outer peripheral portion of the sounding plate, the exciting coil is formed on the sounding plate by printed wiring, and the center of the housing is provided. This can be achieved by facing the arranged magnetic generator with a gap. With this configuration, when a predetermined electric signal is applied to the exciting coil, the exciting coil forms a disk-shaped solenoid with the printed wiring, so that a magnetic field is generated inside, and the influence of the facing magnetic generator is reduced. The receiving and sounding plates vibrate up and down to generate sound, but since the exciting coil does not need to consider the thickness at all, it can be configured as a low-profile electromagnetic acoustic transducer, and because it is formed by printed wiring, there is a risk of disconnection. Absent. As a concrete means for solving the problems, it is preferable that the exciting coil formed by the printed wiring is magnetically plated as in the invention of claim 2.
With this configuration, the exciting coil can be attracted to the magnetic generator when the power is off. As in the invention described in claims 3 and 4, it is preferable that a magnetic body that receives the magnetic field of the magnetic generator is arranged with the sounding plate interposed therebetween, or that the magnetic body is formed of a housing. In this way, the air gap magnetic flux density generated from the magnetic generator can be increased.

Another object of the present invention is to solve the problems described in claim 5 by providing a thin sounding plate arranged in the magnetic field of a magnetic generator and having an outer peripheral portion supported by a housing, and printing on the sounding plate. This can be achieved by forming a first vibrating system with an exciting coil formed of wiring, and constructing a second vibrating system by supporting the magnetic generator with an elastic body supported by a housing. By doing so, both functions of sound (speaker, receiver) and sensible vibration can be exhibited.

According to a sixth aspect of the present invention, it is preferable that a weight that also serves as a magnetic path is attached to the lower portion of the magnetic generator. By doing so, the amount of vibration can be increased. Claim 7
As shown in FIG. 5, the exciting coil formed of the printed wiring is also preferably magnetically plated. With this configuration, the exciting coil can be attracted to the magnetic generator when the power is off. As described in claims 8 and 9, it is preferable that the elastic body has a plate shape or the elastic body has a sponge shape. With this configuration, the second vibration system can be easily configured. As described in claims 10 and 11,
Also in this case, it is preferable that a magnetic body that receives the magnetic field of the magnetic generator is arranged with the movable sound-production diaphragm interposed, or that the magnetic body is formed of a housing. Further, as described in claim 12, it is preferable that the second vibrating system is provided with a restricting member made of an elastic body so that the plate-like elastic body does not exceed a stress limit due to an impact. By doing so, the deformation of the plate-like elastic body can be prevented even if there is an impact such as a drop. Then, as shown in claim 13, a method of using the thin electromagnetic acoustic transducer for mobile communication device according to any one of claims 5 to 12 is mounted on a device through a heat-resistant cushion member. Is desirable. If such a method of use is adopted, the amount of vibration can be felt without being damped by the heavy object on the device side.

[0009]

1 is a sectional view showing a first embodiment of an electromagnetic acoustic transducer for a mobile communication device according to the present invention. FIG. 2 is a plan view showing a state in which a part of the housing is removed from FIG. FIG. 3 is an enlarged cross-sectional view of a main part of a modification of the sounding body of FIG. FIG. 4 is a sectional view of a first modification of the housing in FIG. FIG. 5 is a cross-sectional view of the modified example of FIG. FIG. 6 is a cross-sectional view of an electromagnetic acoustic transducer for a mobile communication device having a vibration generating function as the second embodiment of the present invention. FIG. 7: is sectional drawing explaining the usage method of the 1st modification of FIG. FIG. 8 is a cross-sectional view of the second modification example of FIG.

Next, a magnetic buzzer (also used as a receiver and a speaker) adopted as a first embodiment of the electromagnetic acoustic transducer of the present invention will be described in detail with reference to the drawings. 1 and 2, 1 is 0.025 to 0.05 m
A sounding plate made of a thin film of about 10 m of polyester or polyimide is used to form a thin copper foil of about 0.018 mm on both sides, and a photo-etching technique is used to avoid the main sounding part 1a in the center and to form a spiral through hole 2a. The exciting coil 2 having a large number of turns is formed on both sides by series connection. The magnetic field generated from this exciting coil is entirely inside the coil and is in the vertical direction of the main sounding section 1a in the center. Since the exciting coil is actually formed in a fine pattern with a pitch of about 0.1 mm and is extremely thin and has a narrow interval, its cross section is shown by one solid line for convenience. The sounding plate 1 is a resin base 3 having a solder resistance such as a liquid crystal resin which constitutes a part of the housing (H) on the outer periphery.
The terminal 2b of the printed wiring exciting coil is supported and sealed on the top of the power supply terminal 3b which also functions as a mounting leg portion arranged on the rising portion 3a of the resin base 3 by soldering or welding. The magnetic buzzer thus configured is attached to the printed wiring board B on the device side by soldering with the mounting dummy terminal 3c and the power supply terminal 3b. Resin base 3 that constitutes the housing
A magnetic generator 4 made of a rare earth magnet, which is vertically attached and has a thickness of about 0.6 mm, is made to face the center of the sounding plate 1 with a gap interposed therebetween via a yoke plate 4a. 5 is a resin lid that constitutes the other part of the housing,
A magnetic iron plate 5a forming a magnetic circuit is embedded in the center with the magnetic generator 4 and the sounding plate 1 interposed, and a sound emitting hole 5b is provided. Here, the lid body 5 may be entirely made of a magnetic iron plate in order to form a good magnetic circuit. The magnetic buzzer thus constructed has a low profile because the thickness of the exciting coil 2 can be almost ignored as can be seen from FIG.

The exciting coil 2 formed on the sounding plate 1 is
As shown in FIG. 3, the surface may be magnetic plating MK having a controlled adhesion amount. By doing so, the exciting coil itself can form a magnetic circuit.

Next, referring to FIG. 4, a case where the housing is modified in the above embodiment will be described. That is,
In the base 33 made of a magnetic iron plate (tin plate in this case),
The magnetic generator 4 composed of the rare earth magnet is placed via a heat insulating sheet 4b having an adhesive effect, and the magnetic generator 4 is covered with a sounding plate 11 between them and a lid 55, respectively. It constitutes a magnetic circuit. Base 33
Although various means can be considered for joining the lid 55 and the lid 55,
Here, by welding 35. In order to mount such a magnetism buzzer on a printed wiring board on the device side, it is preferable to stick and mount an acrylic double-sided adhesive sheet S having a strong adhesive effect on the bottom. Here, the sounding plate 11 is
The power supply terminal 11b extends from the outer peripheral portion in a tongue shape and is hung from the outside of the base 33 to be soldered to the printed wiring board B on the device side. Of course, the sound board 1
In the portion 1 sandwiched between the base 33 and the lid 55, the printed wiring exciting coil 22 is considered to be insulated. According to this structure, as can be seen from FIG. 4, the yoke plate is not required, so that the thickness can be further reduced.

FIG. 5 is a modification of FIG. 4, in which the base 34 and the lid 56 are abutted against each other and the base 34 side is placed so as to be embedded in the printed wiring board B1 on the device side. In this way, the posture can be further lowered.

Next, a description will be given of an electromagnetic acoustic transducer including a second vibration system in addition to the vibration system described above and having a function of generating a sensory vibration as a silent notification means of a mobile communication device. In FIG. 6, a weight 4a made of a magnetically-plated tungsten alloy is attached to the magnetic generator 4 to form a movable magnetic pole body W. The movable magnetic pole body W is placed on a plate-like elastic body 6 having magnetism. The second vibrating system is configured so that the outer peripheral portion of the plate-like elastic body 6 is supported by the housing so as to be supported in the air and moved up and down. In the figure,
Reference numeral 6a is a magnetic circuit auxiliary member which also serves as one of the impact resistance restricting members of the movable magnetic pole body W. Here, the other members may have the same configuration as described above, but the resin base and the lid may contain magnetic powder to form a magnetic circuit. Also here, the printed wiring exciting coil 2 may be formed with magnetic plating as described above. Here, in each of the illustrated members, the same parts are designated by the same reference numerals, and description thereof will be omitted. The plate-like elastic body 6 is additionally provided with vertical movement restricting members 7 and 77 formed of cushion members so as not to be deformed beyond a stress limit even when an impact such as a drop is applied. Even if the vertical movement restricting member is arranged on the fixed side, the operation and effect are the same. The weight of the tungsten alloy can be expected to function as a yoke by magnetic plating. Further, the weight may be composed of a magnetic iron plate.
Further, the weight escape hole 3d formed in the base 3 may be closed by the second base 3e aiming at a resonance effect as shown by an imaginary line. As described above, even in the embodiment of the electromagnetic acoustic transducer having the second vibrating system, the thickness of the exciting coil can be almost ignored as can be judged from FIG.

Such an electroacoustic transducer having the second vibration system is applied to the printed wiring board on the device side by inserting the heat-resistant sponge-like cushion member SC as shown in FIG. It is possible to adopt the usage method of mounting on B. In this case, the exciting coil 22 formed on the sounding plate 11 has the same structure as that described with reference to FIG.
1 is extended from the outer peripheral portion in a tongue shape with a sufficient margin as a power supply terminal, and is hung from the outside of the base 33 to be soldered to a printed wiring board B on the device side.
Here, the base and the lid may be formed of a magnetic metal, and in such a case, the sound producing plate 11 is naturally used.
In the portion sandwiched between the base 33 and the lid 55, the printed wiring exciting coil 22 is considered to be insulated.

FIG. 8 shows a modification of the second vibration system, which is a yoke plate 4aa which also serves as a magnetic generator 4 and a weight serving as its magnetic path.
The sponge-like cushion member SP to support the base 33
3 supported. Even in this case, the yoke plate 4a also serving as the magnetic body 4 and the weight serving as the magnetic path thereof.
The second vibration system composed of a can obtain vertical vibration by energizing the exciting coil 2.

The present invention can take various other embodiments without departing from the technical idea and features thereof. Therefore, the above-described embodiment is merely an example and should not be limitedly interpreted. The technical scope of the present invention is shown by the claims and is not bound by the text of the specification.

[0018]

As described above, according to the first aspect of the present invention, since the exciting coil does not need to take the thickness into consideration, it can be constructed as a low-profile electromagnetic acoustic transducer and formed by printed wiring. There is no risk of disconnection. According to the invention described in claim 2, since the exciting coil constitutes a magnetic circuit and can be attracted to the magnetic generator when there is no energization, the exciting coil can be driven by a half-wave AC having only repulsion. According to the invention described in claims 3 and 4, the air gap magnetic flux density generated from the magnetic generator can be increased. According to the invention described in claim 5, it is possible to perform both low-profile sound and vibration functions. According to the invention described in claim 6, it is possible to increase the vibration amount. According to the invention described in claim 7, the exciting coil can also be attracted to the magnetic generator when there is no energization, and can be driven by a half-wave AC having only repulsion. According to the invention described in claims 8 and 9, if it does in this way, the 2nd vibration system can be constituted simply. According to the invention described in claims 10 and 11, the air gap magnetic flux density generated from the magnetic generator can be increased also here. According to the twelfth aspect of the present invention, it is possible to prevent deformation of the plate-like elastic body even if there is an impact such as a drop. Further, according to the invention as set forth in claim 13, by utilizing the advantage of thinness, the vibration amount can be felt without being attenuated by the heavy object on the device side.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of an electromagnetic acoustic transducer for a mobile communication device of the present invention.

FIG. 2 is a plan view showing a state in which a part of the housing is removed from FIG.

FIG. 3 is an enlarged sectional view of a main part of a modification of the sounding body of FIG.

FIG. 4 is a cross-sectional view of a modified example of the housing in FIG.

5 is a cross-sectional view of a modified example of FIG.

FIG. 6 is a cross-sectional view of an electromagnetic acoustic transducer for a mobile communication device having a vibration generating function as a second embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a method of using the first modified example of FIG.

FIG. 8 is a sectional view of a second modification example of FIG.

FIG. 9 is a cross-sectional view of a conventional electroacoustic transducer.

[Explanation of symbols]

1, 11 sound plate 2.22 Excitation coil 3,33,34,333 Base 4 Magnetic generator 5, 55, 555 lid 6 Plate-like elastic body 7,77 Control member S, SC Sponge cushion material

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5D107 AA03 AA13 BB08 CC09 CC10                       DD12 FF10                 5H607 AA17 BB20 BB27 CC01 CC09                       DD02 DD09 EE57 JJ08 JJ09                       KK08                 5H633 BB07 GG02 GG03 GG06 GG08                       GG30 HH02 HH03 HH05 HH09                       HH16 HH24 HH29 JA03 JA04                       JA05

Claims (13)

[Claims] 1. An electromagnetic acoustic transducer comprising a thin sounding plate arranged in a magnetic field of a magnetic generator and having an outer peripheral portion supported by a housing, and an exciting coil arranged on the sounding plate, wherein the exciting coil is printed. A thin electromagnetic acoustic transducer for a mobile communication device, which is formed on a sounding plate by wiring and is opposed to the magnetic generator disposed in the center of the housing via a gap. 2. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 1, wherein the exciting coil formed by the printed wiring is magnetically plated. 3. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 1, wherein a magnetic body that receives the magnetic field of the magnetic generator is arranged with the sounding plate interposed therebetween. 4. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 3, wherein the magnetic body is a housing. 5. A first vibrating system is constituted by a thin sounding plate arranged in a magnetic field of a magnetic generator and having an outer peripheral portion supported by a housing, and an exciting coil formed by printed wiring on the sounding plate.
A thin electromagnetic acoustic transducer for a mobile communication device, wherein the magnetic generator is supported by an elastic body supported by the housing to form a second vibration system. 6. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 5, wherein a weight that also serves as a magnetic path is attached to a lower portion of the magnetic generator. 7. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 5, wherein the exciting coil formed by the printed wiring is magnetically plated. 8. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 5, wherein the elastic body has a plate shape. 9. The elastic body is sponge-shaped.
A thin electromagnetic acoustic transducer for mobile communication device according to. 10. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 5, wherein a magnetic body that receives the magnetic field of the magnetic generator is arranged with the movable sound generating plate interposed therebetween. 11. The thin electromagnetic acoustic transducer for a mobile communication device according to claim 10, wherein the magnetic body is a housing. 12. The thin electromagnetic acoustic device for a mobile communication device according to claim 8, wherein a restricting member made of an elastic body is arranged on the second vibration system so that the plate-like elastic body does not exceed a stress limit due to an impact. converter. 13. The method according to any one of claims 5 to 12
A thin electromagnetic-acoustic transducer for a mobile communication device, wherein the thin electromagnetic-acoustic transducer for a mobile communication device according to the item is mounted on a device via a heat-resistant cushion member.