JP2010114866A - Panel-type speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel-type speaker having improved in lower-register acoustic characteristics. <P>SOLUTION: A panel-type speaker includes: a longitudinally long frame (11) mounted inside an electronic apparatus; longitudinally long diaphragms (12, 12a) of which both the terminal portions in a length direction are elastically supported on the frame (11); longitudinally long support plates (14, 14a) of which both the terminal portions, in a length direction, are elastically supported on the frame (11) and which are extended in parallel, while maintaining a substantially fixed interval with respect to the diaphragm (12a); and moving-coil type actuators (13a, 13b), of which the rear end portion is supported on the supporting plate (14a) and of which the tip portion is adhered and fixed on the rear side of the diaphragm (12a). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a panel-type speaker mounted inside an electronic device such as a personal computer or a liquid crystal display, and more particularly to a panel-type speaker having excellent sound quality with excellent acoustic characteristics in a low sound range.

  Conventionally, small and thin panel type speakers have been developed for use in electronic devices such as personal computers and liquid crystal displays. This panel speaker has a structure in which a movable wire ring type actuator is attached to the back side of an elongated diaphragm, and the diaphragm is excited by flexural vibration with good sound quality. As a method for attaching the actuator to the diaphragm, there is a method in which the actuator is suspended by bonding and fixing the tip of the actuator to the back side of the diaphragm (Patent Document 1).

Generally, in the above-mentioned panel type speaker having a suspended structure, there is a risk that the adhesive layer may be peeled off when an impact force or the like is applied in a state where the adhesive has deteriorated over time. Therefore, in order to further improve durability over a long period of time, the rear end of the actuator is directly or softly interposed on the bottom plate of a large rigid frame for supporting the diaphragm and the housing of the electronic device. The structure of fixing while making it have been employed (Patent Document 2).
JP 2006-121325 A JP 2007-243851 A

  In the conventional panel type speaker described above, in the structure in which the rear end portion of the actuator is fixed to the bottom plate of the large rigid frame for supporting the diaphragm, the housing of the electronic device or the like while interposing a soft elastic body, There was a problem in acoustic characteristics that the characteristics of the low frequency range were not sufficient.

  Accordingly, an object of the present invention is to provide a panel type speaker having good acoustic characteristics and sufficient low-frequency characteristics.

  The panel-type speaker of the present invention that solves the above-mentioned problems of the prior art includes an elongated frame that is attached to an electronic device such as a personal computer or a liquid crystal display, and both longitudinal ends thereof are elastically held by the frame. An elongated diaphragm, an elongated support plate that is elastically held at both ends in the longitudinal direction by the frame, and is extended in parallel with the diaphragm at a substantially constant interval, and a rear end. And a movable wire ring type actuator that is supported by the support plate and whose tip is bonded and fixed to the back surface of the diaphragm.

  According to the panel type speaker of the present invention, the front end portion of the movable wire ring type actuator is bonded and fixed to the back surface of the diaphragm, and the rear end portion is supported by the support plate. In addition, the support plate that supports the rear end of this actuator has a slender, soft structure that allows the actuator to vibrate in the front-rear direction, similar to the diaphragm. A panel speaker with good sound quality can be realized.

  According to one of the best modes of the present invention, the support plate is a plate capable of adjusting rigidity while maintaining a thickness necessary for supporting the actuator by forming a plurality of openings at regular intervals. Due to the shape, it is possible to easily realize the optimum rigidity for flexural vibration in the low sound range.

  According to another one of the best modes of the present invention, the elongated diaphragm is a honeycomb-structured core material made of an aluminum alloy, and a kraft paper material adhered to both front and back surfaces of the core material. Therefore, a panel type speaker with good sound quality can be realized.

  According to yet another of the best modes of the present invention, it is further improved by further comprising a thin rectangular housing made of an aluminum alloy that is crowned on the surface of the honeycomb structured diaphragm. A panel-type speaker with a good sound quality can be realized.

  According to still another preferred embodiment of the present invention, the support plate is made of an aluminum alloy, and the support plate also serves as a heat dissipation function for heat released from the magnetic circuit of the actuator. It becomes possible to reduce the temperature change width and prevent the temperature change of the acoustic characteristics.

  1, 2 and 3 are a cross-sectional view, an enlarged partial cross-sectional view and an exploded perspective view showing the configuration of the panel type speaker 10 of one embodiment of the present invention. In each figure, 11 is a frame, 12 is a diaphragm assembly, 13 is an actuator, and 14 is a support plate assembly.

  The panel type speaker of this embodiment is installed in a stationary electronic device such as a personal computer or a liquid crystal display device. The elongated frame 11 made of a mold resin is integrally formed by injection molding. At both ends of the frame 11 in the longitudinal direction, flange portions 11a for attaching the frame 11 of the panel type speaker of this embodiment to an electronic device are formed. Further, the frame 11 is formed with four stoppers 14c in the longitudinal direction for preventing excessive vibration of the diaphragm.

  A panel-type speaker comprising a resin-made column post 2a formed integrally with the case 1 and a soft rubber grommet 2b fitted to the column post is provided in the case 1 of the stationary electronic device. The fixing mechanism 2 is formed. The frame 11 is attached to the housing 1 of the electronic device via the fixing mechanism 2 by fitting the flange portions 11 a formed at both ends thereof to the grommet 2 b of the fixing mechanism 2. Since the grommet 2b is made of soft rubber, the sound generated by the panel type speaker is absorbed by the fixing mechanism 2, and the situation where unnecessary resonance noise is generated from the housing 1 is effectively avoided. .

  A vibration plate assembly 12 and a support plate assembly 14 are attached to the frame 11. The support plate 14a of the support plate assembly 14 is fixed to the back surface of the frame 11 with an adhesive while interposing an elastic body 14b of soft rubber or sponge that is bonded and fixed to the surface thereof. Two actuators 13a and 13b are supported at the longitudinal center of the support plate 14a. This actuator is supported by press-fitting a magnetic circuit at the rear end of each actuator 13a, 13b into an opening formed in the support plate 14a.

  As shown in the exploded perspective view of FIG. 3, four disk-shaped protrusions are formed at equal intervals in the circumferential direction at the respective tip portions of the actuators 13a and 13b. The actuators 13a and 13b are bonded and fixed to the back surface of the vibration plate 12a via four disc-shaped resin protrusions formed at the respective tip portions. The four protrusions function to form an air escape path in the voice coil between them.

  The diaphragm 12a of the diaphragm assembly 12 has a sandwich structure in which kraft paper materials are attached to both front and back surfaces of a honeycomb structure core material made of an aluminum alloy. On the surface side of the diaphragm 12a, a casing 12b made of a thin aluminum alloy is attached with its open end facing downward. The diaphragm 12a has elastic edges 12c made of urethane, soft rubber, or poron, which are curved in a bowl shape, and outermost frame portions 12d at both ends in the longitudinal direction. The frame 11 is elastically supported. The addition of the housing 12b improves the high frequency acoustic characteristics.

  A circular opening having an appropriate diameter is formed in the support plate 14a made of a soft resin material while maintaining a constant interval in the longitudinal direction and the lateral width direction. By adjusting the size and number of the openings, appropriate rigidity and weight are adjusted with respect to the flexural vibration of the support plate 14a while maintaining a certain thickness suitable for holding the actuators 13a and 13b. Since the rear end portions of the actuators 13a and 13b are held by the frame 11 while interposing the appropriate rigidity of the support plate 14a and the appropriate elasticity of the elastic body 14b, the actuators 13a and 13b 13b can easily generate vertical vibrations in the low frequency range, and flexural vibrations in the low frequency range can be excited to the diaphragm 12a with high efficiency.

  FIG. 4 is experimental data showing the acoustic characteristics of the panel type speaker of the above embodiment compared with the acoustic characteristics of a conventional panel type speaker. The horizontal axis represents frequency, and the vertical axis represents sound pressure (dB). Curve A is the acoustic characteristic of the embodiment of the present invention shown in FIGS. 1 to 3, and B is the acoustic characteristic of the conventional panel type speaker in which the actuator is directly fixed to the casing of the electronic device. It can be seen that the characteristics of the panel type speaker of this example are substantially the same as those of the conventional high-frequency characteristics, but the characteristics of the low-frequency side of 300 Hz or less are improved compared to the conventional characteristics.

  Heretofore, the configuration in which the support plate 14 is integrally formed of resin has been exemplified. However, the material of the diaphragm may be an aluminum alloy, and may also serve as a heat radiating plate against the heat generated in the magnetic corridor at the rear end of the actuator.

  Moreover, the structure which comprises the grommet 2b of the fixing mechanism 2 with soft rubber was illustrated. However, the grommet 2b may be made of resin, and a structure in which a soft rubber layer is interposed between the grommet 2b and the post 1b and the grommet 2b is fitted to the post 11b. In this way, the sound generated by this panel type speaker can be absorbed by the fixing mechanism 2. For this purpose, a structure in which a rubber mat is interposed between the post 2a and the housing 1 effectively absorbs sound generated by the panel type speaker by the fixing mechanism 2 and is unnecessary from the housing 1. It is possible to avoid a situation in which a simple resonance sound is generated.

  Furthermore, a configuration in which the panel type speaker of the present invention is built in a stationary electronic device such as a personal computer or a liquid crystal display device is illustrated. However, in order to take advantage of the good low-frequency characteristics, it can also be incorporated in a mobile phone that requires resistance to excessive impact force.

  It is sectional drawing which shows the structure of the panel type speaker of one Example of this invention.   It is an expanded partial sectional view which shows the structure of the panel type speaker of the said Example.   It is a disassembled perspective view which shows the structure of the panel type speaker of the said Example.   It is experimental data which shows the acoustic characteristic of the panel type speaker of the said Example, comparing with the conventional one.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cellular phone case 2 Panel type speaker fixing mechanism to case 1 2a Post 2b Grommet 10 Panel type speaker 11 Frame 12 Diaphragm assembly 13a, 13b Movable ring type actuator 14 Support plate assembly 14a Support plate

Claims (7)

An elongated frame attached to the inside of the electronic device;
An elongated diaphragm whose both ends in the longitudinal direction are elastically supported by this frame;
An elongated support plate that is elastically held at both ends in the longitudinal direction on the frame and extends in parallel with the diaphragm at a substantially constant interval;
A panel type speaker comprising: a movable wire ring type actuator having a rear end portion supported by the support plate and a front end portion bonded and fixed to the back surface of the diaphragm. In claim 1,
The panel-type speaker is characterized in that the support plate is formed of a plate-like body capable of adjusting rigidity while maintaining a thickness necessary for supporting the actuator by forming a plurality of openings at a constant interval. In either claim 1 or 2,
The diaphragm is composed of a honeycomb-structured core material made of an aluminum alloy, and a kraft paper material adhered to both front and back surfaces of the core material. In any one of Claims 1 thru | or 3,
A panel-type speaker, further comprising a thin rectangular casing made of an aluminum alloy that is attached to the surface of the diaphragm. In any one of Claims 1 thru | or 4,
A panel type speaker characterized in that the support plate is made of an aluminum alloy, and the support plate also has a function of radiating heat released from the magnetic circuit of the actuator. In any one of Claims 1 thru | or 5,
The panel-type speaker, wherein the frame is attached to the inside of the electronic device with a cushioning material interposed. In any one of Claims 1 thru | or 6.
A panel-type speaker, wherein the electronic device is a portable electronic device.

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