JP4177249B2 - Sound playback device - Google Patents

Description

  The present invention relates to a sound reproducing device that vibrates a sound generating panel such as a transparent panel of a display unit, and particularly relates to a sound reproducing device capable of improving sound pressure.

  An example of a panel-type sound reproducing device that vibrates a panel to generate sound is disclosed in Patent Document 1 below, for example.

In Patent Document 1, a transparent panel is fixed to an opening formed in a case of a mobile phone, a liquid crystal display element is provided inside the panel, and an image displayed on the liquid crystal display element through the panel is displayed. It can be visually recognized. Further, a piezoelectric vibration element is fixed inside the panel so as not to overlap the liquid crystal display element, and the piezoelectric vibration element vibrates when a voltage is applied, and this vibration is transmitted to the panel so that the panel is Pronounce.
JP 2002-232542 A

  However, in a relatively small device such as a mobile phone as described in Patent Document 1, the panel mounted on the device is also small, and as a result, the vibration area of the panel is reduced and it is difficult to output with high sound pressure. Become.

  Moreover, in the thing of the said patent document 1, reducing the resonant frequency of a panel and suppressing a high frequency band is proposed by forming a space between a panel and a piezoelectric vibration element. However, if the output on the high sound side is suppressed too much, the sound quality may deteriorate.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a sound reproducing device capable of improving sound pressure over a wide frequency band without impairing sound quality.

The present invention provides a sound reproducing apparatus provided with a sound generation panel elastically supported by a base and vibration generating means for generating vibration by applying vibration to the sound generation panel.
The vibration generating means includes a long-shaped excitation member whose both ends are connected to the sound generation panel, and a drive means provided between the sound generation panel at a central portion thereof,
A part of the sound generation panel is directly or indirectly fixed to the base and constrained on an excitation reference line extending in a direction perpendicular to the longitudinal direction of the excitation member through the driving means. It is a feature.

  In this sound reproducing apparatus, since the sound generation panel is restrained outside the place where the vibration generating means is provided, a line connecting the vibration generating means and the fixed portion where the sound generation panel is restrained becomes a node. The pronunciation panel vibrates with a large amplitude.

For example, on the excitation reference line, in which fixing unit for fixing the base and the pronunciation panel is provided.

  With this configuration, since vibration is applied to the connecting portion between the excitation member and the sound generation panel on both sides of the excitation reference line, the sound generation panel is subjected to a large vibration with the excitation reference line as a node. .

  In this case, the sound generation panel may be rectangular, and the driving means and the fixed portion may be arranged at the center of the long side inside the long sides facing each other.

  Alternatively, the sound generation panel has a long shape in which the vertical dimension is longer than the horizontal dimension, and the driving means and the fixing part are both spaced apart in the horizontal direction at the central part that bisects the vertical direction. Can be configured.

Further, the present invention provides a sound reproducing apparatus provided with a sound generation panel elastically supported by a base and vibration generating means for applying vibration to the sound generation panel to generate sound.
The vibration generating means includes a long-shaped excitation member whose both ends are connected to the sound generation panel, and a drive means provided between the sound generation panel at a central portion thereof,
As the driving means, the excitation reference line extending in a direction orthogonal to the longitudinal direction of the excitation member by clamping free on both sides, a portion of the sound panel, directly or indirectly fixed with constrained to the base It is characterized by being.

  In this case, vibration nodes are formed on the line connecting the driving means and the one fixing portion and on the line connecting the driving means and the other fixing portion, so that the sound generation panel can vibrate effectively.

  The present invention can improve sound pressure over a wide frequency band without impairing sound quality even when mounted on a small device.

  FIG. 1 is a plan view showing a sound reproducing apparatus according to a first embodiment of the present invention, FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1, FIG. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

  As shown in FIGS. 1 and 2, the sound reproducing device 1 has a transparent panel 2 as a sound generation panel, and a damper 3 having long and short sides of the panel 2 formed of an elastic material such as synthetic rubber. It is elastically supported on the base 4 via. The panel 2 is formed in a square shape with a plate material of synthetic resin such as polycarbonate, acrylic, or PET (polyethylene terephthalate). The base 4 is made of synthetic resin or metal and is formed with a size that is slightly larger than the panel 2. The base 4 may be a casing of an electronic device such as a mobile phone. One surface side of the damper 3 is fixed to the outer peripheral edge of the panel 2, and the other surface side is fixed on the base 3.

  As shown in FIGS. 1 and 2, vibration generating means 5 and a fixing member 6 are provided inside the panel 2 with a space therebetween.

As shown in FIG. 4, the vibration generating means 5 has an elongate (long shape) excitation member 7 whose dimension in the X direction is sufficiently longer than the dimension in the Y direction. The excitation member 7 is formed of a magnetic material such as a steel plate, and connection portions 7a and 7a bent in an L shape are formed at both ends in the X direction, and the connection portions 7a and 7a are connected to the panel 2. It is fixed inside with an adhesive. In addition, although not shown in figure, the bending part may be formed in the dimension which does not contact the said panel 2 in the both sides extended in the Y direction of the said excitation member 7. FIG.

  A magnet 8 made of a permanent magnet such as ferrite or rare earth is fixed to the bottom 7 b facing the panel 2 on the excitation member 7, and a yoke 9 made of a magnetic material is overlapped on the upper surface of the magnet 8. ing. The upper surface of the yoke 9 is set to a size that does not contact the panel 2 when the magnet 8 and the yoke 9 are overlapped with the bottom 7b.

  On the other hand, the panel 2 is provided with a coil 10 on the side facing the excitation member 7. The coil 10 is formed by winding a coated copper wire or the like into a coil shape. When the excitation member 7 is fixed to the panel 2, the magnet 8 and the yoke 9 are connected to the coil 10. It is inserted in a state where gaps G with minute intervals are formed inside.

  For example, in the magnet 8, when the Z1 side is magnetized to the N pole and the Z2 side is magnetized to the S pole, the magnetic field generating means for applying a magnetic field to the coil 10 by the magnet 8, the yoke 9, the gap G, and the excitation member 7 Is formed. When the bending portion is formed on the excitation member 7, a current path extending in the X direction of the coil 10 is positioned between the magnet 8 and the yoke 9 and the bending portion. The bent portion can function as an opposing yoke.

  When the coil 10 is energized, the panel 2 and the excitation member 7 are deformed in a direction toward and away from each other based on Fleming's left-hand rule. In this embodiment, the magnetic field generating means and the coil 10 constitute magnetic driving means.

  As shown in FIG. 4, the excitation member 7 is connected to the panel 2 via connecting portions 7a and 7a at both ends in the longitudinal direction, and the magnetic drive means is provided at the center of the connecting portions 7a and 7a. ing. Therefore, vibration is generated between the excitation member 7 and the panel 2 between the connecting portion 7a and the connecting portion 7a by the driving force of the magnetic driving means, and this vibration is transmitted from the connecting portions 7a and 7a to the panel 2. Given.

  As shown in FIG. 1, an imaginary line passing through the magnetic drive means, that is, passing through the central portion that bisects the excitation member 7 in the longitudinal direction, and extending in a direction perpendicular to the longitudinal direction of the excitation member 7 is defined as an excitation reference line O. The fixing member 6 is located on the excitation reference line O. The panel 2 has a rectangular shape, and the excitation reference line O is located at a position that bisects the long side. Therefore, in this embodiment, the excitation reference line O becomes a vibration node of the panel 2.

  In the vibration generating means 5, the drive means for generating vibration between the excitation member 7 and the panel 2 is not limited to the magnetic drive means, but directly to the excitation member 7 and the panel 2 or indirectly via other members. It may be a piezoelectric element fixed to.

FIG. 7 is a sectional view showing a modification of the vibration generating means shown in FIG. In this vibration generating means 5A, a coil 10 is provided on a sheet 11 made of synthetic resin such as PET or polycarbonate, and this sheet 11 is bonded and fixed to the panel 2. Further, the connecting portions 7 a and 7 a of the excitation member 7 are fixed to the sheet 11, and the excitation member 7 is connected to the inside of the panel 2 through the sheet 11. In the present embodiment, since the coil 10 may be formed on the surface of the sheet 11, it is easy formation of the coil 10 is. Further, the manufacturing process can be simplified by forming the coil 10 on the sheet 11, bonding and fixing the excitation member 7 to the sheet 11, and then bonding the sheet 11 to the panel 2.

  In the sound reproducing device 1 shown in FIG. 1, a rectangular opening 4a is formed in the base 4 as shown in FIG. 3. For example, a liquid crystal display element is provided on the back side of the opening 4a, and vibration generating means 5 and By arranging so as not to overlap the fixing member 6, an image or video output from the liquid crystal display element can be visually recognized through the panel 2. Therefore, sound can be generated from the front surface of the liquid crystal display element.

  As shown in FIG. 1, in the sound reproducing apparatus 1, the vibration generating means 5 is provided at one edge of the panel 2 in the Y direction, and the fixing member 6 is provided at the other edge. The panel 2 is a rectangle whose X-direction dimension is longer than the Y-direction dimension, and is arranged in parallel in the vicinity of the long side edge of the panel 2 so that the longitudinal direction of the excitation member 7 coincides with the X direction. Has been. Further, the excitation member 7 is located at the center of the long side of the panel 2, and thus the magnetic drive means is also located at the center of the long side.

  The fixing member 6 is formed of a rigid body such as a synthetic resin or a metal, and is provided between the panel 2 and the base 4. The fixing member 6 in the present embodiment is formed such that the dimension in the X direction is longer than the dimension in the Y direction and shorter than the dimension in the X direction of the excitation member 7 of the vibration generating means 5. In the fixing member 6 in the present embodiment, a notch 3a is formed in a part of the damper 3 formed in a frame shape, and the fixing member 6 is provided in the notch 3a. Further, the fixing member 6 is provided in the center of the long side in the vicinity of the long side of the panel 2.

  The fixing member 6 is not limited to a rigid body formed in a block shape. For example, if the base 4 is formed of a metal plate, the base 4 is formed in an L shape on the panel 2 side. The front end surface may be fixed to the panel 2 by bending.

  The length dimension, width dimension and thickness dimension of the fixing member 6 and the length dimension of the vibration generating means 5 can be appropriately changed.

Next, the operation of the sound reproducing device 1 will be described.
In this sound reproducing apparatus 1, when the coil 10 is energized based on an audio signal or a music signal, the vibration generating means 5 generates self-vibration in the Z direction by a magnetic driving force. Since the periphery of the panel 2 is supported via the damper 3, the panel 2 itself vibrates.

  As shown in FIGS. 4 and 7, in the vibration generating means 5 (5A), when a vibration force acts between the excitation member 7 and the panel 2 in the magnetic drive means having the magnet 8 and the coil 10, the excitation member 7 is used. Bends and deforms with the central portion provided with the magnet 8 as a fulcrum. For example, when the magnet 8 is attracted to the panel 2 in the Z1 direction, when the panel 2 is pulled in the Z2 direction by the connecting portions 7a and 7a at both ends of the excitation member 7, and the magnet 8 repels in the Z2 direction, The panel 2 is pushed in the Z1 direction by the connecting portions 7a and 7a.

  Here, the fixing member 6 is positioned on the excitation reference line O with an interval in the Y direction in the magnetic driving means of the vibration generating means 5, and the panel 2 is partially restrained by the fixing member 6. Yes. The connecting portions 7a and 7a are located on both sides of the excitation reference line O. Accordingly, the panel 2 vibrates with the excitation reference line O as a node. For this reason, even if the area of the panel 2 is small, the vibration becomes large, and the sound output can be increased in a wide frequency band.

  FIG. 8 is a graph comparing the comparative example and the embodiment in terms of the relationship between frequency (Hertz) and sound pressure level (SPL) (decibel). In FIG. 8, a graph indicated by a dotted line is a comparative example, and a graph indicated by a solid line is the present embodiment.

  In the comparative example shown in the sound reproducing device 1 of the first embodiment, the damper 3 is provided on the entire periphery of the panel 2 and is fixed to the base 4 without providing the fixing member 6.

  As shown in FIG. 8, in the comparative example, the sound pressure is output low from the low frequency region to the high frequency region, but this is the vibration in the opposite directions when the vibration generating means 5 is driven to vibrate the panel 2. This is thought to be offset. On the other hand, in the case where the fixing member 6 is provided as in the present embodiment, the sound pressure can be improved over a wide band from the low frequency region to the high frequency region.

  FIG. 5 is a plan view showing the sound reproducing device 1A of the second embodiment, and FIG. 6 is a modification of FIG. Each of the sound reproducing apparatuses 1A and 1B has elliptical panels 2A and 2B. Dampers 3A and 3B are provided on the peripheral edges of the panels 2A and 2B, and the panels 2A and 2B are bases (not shown). ) Are elastically supported on each. The vibration generating means has the same configuration as the vibration generating means 5.

  The present invention is not limited to the above embodiment, and various modifications can be made. For example, in the embodiment shown in FIG. 1, the panel 2 has a rectangular shape with long sides extending in the X direction, but the panel 2 has an oval shape in which the vertical dimension in the X direction is longer than the horizontal dimension in the Y direction. It may be oval or polygonal. In this case, the vibration generating means 5 and the fixing member 6 are respectively provided in the center which is spaced in the Y direction and bisects the vertical direction. Therefore, the excitation reference line O also extends in the Y direction at a position that bisects the vertical direction (X direction).

  5 and 6 show the sound reproducing apparatuses 1A and 1B according to still another embodiment of the present invention.

  In the sound reproducing device 1A shown in FIG. 5, the vibration generating means 5 is arranged closer to the X1 side than the center O1 of the panel 2A so that the longitudinal direction coincides with the Y direction. Fixing members 6A and 6A are provided at a predetermined distance from each other on the X2 side facing the vibration generating means 5 across the center O1. The fixing members 6A and 6A are obtained by replacing a part of the damper 3A with a rigid body such as a synthetic resin or metal, and are arranged symmetrically with respect to the X axis on the panel 2A.

  In this embodiment, a line extending in the X direction through the center O1 is an excitation reference line, and the fixing members 6A and 6A are arranged at equidistant positions on both sides in the Y direction across the excitation reference line. Has been.

  In the sound reproducing apparatus 1A, when the coil 10 is energized and the vibration generating means 5 is driven, the vibration at that time is transmitted to the entire panel 2A, but the vibration generating means and each of the fixing members 6A and 6A are transmitted. The lines connecting the centers of the lines 5 become vibration nodes and vibrate, so that the sound pressure can be improved particularly in the high frequency band.

  In the sound reproducing apparatus 1B shown in FIG. 6, the vibration generating means 5 is arranged in the center of the panel 2B so that the Y direction coincides with the longitudinal direction, and the X1 side is sandwiched by the center O2 (vibration generating means 5). Fixing members 6B and 6B formed of a rigid body similar to the above are provided at the end of the X2 and the end of the X2 side. Also in this case, the excitation reference line extends in the X direction through the center O2, and the fixing members 6B and 6B are located on the excitation reference line. Therefore, sound pressure can be improved in a wide frequency band.

In the sound reproducing devices 1A and 1B, if the base is formed of a metal plate, the metal plates may be cut and raised to fix the panels 2A and 2B using this as a fixing member. Good. Further, as shown in FIG. 7, the vibration generating means 5 may be integrated using a sheet 11 to simplify the manufacturing process.
The fixing member 6 may be provided at the center of the panels 2, 2A, 2B.

The top view which shows the sound reproduction apparatus of the 1st Embodiment of this invention, 2 arrow view of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. The top view which shows other embodiment of the sound reproduction apparatus of this invention, The top view which shows other embodiment of the sound reproduction apparatus of this invention, Sectional drawing which shows the modification of a vibration generation means, A graph comparing the comparative example and the embodiment in relation to the frequency and the sound pressure level,

Explanation of symbols

1, 1A, 1B Sound reproducing device 2, 2A, 2B Panel 3, 3A, 3B Damper 4 Base 4a Opening 5, 5A Vibration generating means 6, 6A, 6B Fixing member 7 Excitation member 7a Connecting portion 8 Magnet 9 Yoke 10 Coil 11 sheets

Claims (6)

In a sound reproducing device provided with a sound generation panel elastically supported by a base and vibration generating means for applying vibration to the sound generation panel to generate sound,
The vibration generating means includes a long-shaped excitation member whose both ends are connected to the sound generation panel, and a drive means provided between the sound generation panel at a central portion thereof,
A part of the sound generation panel is directly or indirectly fixed to the base and constrained on an excitation reference line extending in a direction perpendicular to the longitudinal direction of the excitation member through the driving means. A characteristic sound reproducing apparatus. The upper to the excitation reference line, sound reproducing apparatus according to claim 1, wherein the fixing unit for fixing the base and the pronunciation panel is provided.   The sound reproducing device according to claim 2, wherein the sound generation panel is rectangular, and the driving unit and the fixed portion are arranged in the center of the long side inside the long sides facing each other.   The sound generation panel has an elongated shape whose longitudinal dimension is longer than the lateral dimension, and the driving means and the fixing portion are both spaced apart in the lateral direction at the central portion that bisects the longitudinal direction. The sound reproducing device according to claim 2. In a sound reproducing device provided with a sound generation panel elastically supported by a base and vibration generating means for applying vibration to the sound generation panel to generate sound,
The vibration generating means includes a long-shaped excitation member whose both ends are connected to the sound generation panel, and a drive means provided between the sound generation panel at a central portion thereof,
As the driving means, the excitation reference line extending in a direction orthogonal to the longitudinal direction of the excitation member by clamping free on both sides, a portion of the sound panel, directly or indirectly fixed with constrained to the base A sound reproducing device characterized by being provided . The sound reproducing device according to claim 5, wherein fixing portions for fixing the base and the sound generation panel are provided on both sides of the excitation reference line, respectively .

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