Panel speaker

Abstract

To suppress reduction of a sound pressure level in a panel speaker.SOLUTION: A panel speaker 10a includes: a first panel 111; a second panel 112; and a vibration actuator 14 for vibrating the first panel 111 and the second panel 112. The panel speaker 10a includes: an adhesive layer 150 for joining one surface of the first panel 111 with one surface of the second panel 112; and a connection part for joining the other surface of the first panel 111 with the vibration actuator 14. The adhesive layer 150 includes first areas being a plurality of parallel belt-shaped areas in plan view of the first panel 111. The connection part is arranged in an area held between the first areas in the plan view of the first panel 111. The adhesive layer 150 also includes a second area between the one first area between the two adjacent first areas on both sides of the connection part and the connection part in the plane view of the first panel 111.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a panel speaker. [Background technology]

[0002] 2. Description of the Related Art Conventionally, flat panel speakers have been known in which an actuator (exciter) installed on a panel vibrates the panel to emit sound from the panel surface (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-9473 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional panel speakers have a problem in that the sound pressure level decreases in some frequency ranges.

[0005] For example, consider a case where a diaphragm panel, which is made by bonding a first panel and a second panel with double-sided tape or the like, is excited by an actuator installed on the first panel to vibrate and emit sound. In this case, depending on the positional relationship between the vibration position of the first panel and the bonding area, the vibration position of the first panel may be strongly restricted, resulting in vibration attenuation, i.e., a drop in sound pressure level, especially in the high-frequency range.

[0006] The present invention has been made in view of the above, and has an object to provide a panel speaker in which the sound pressure level is less likely to decrease. [Means for solving the problem]

[0007] In order to solve the above problems and achieve the object, a panel speaker according to the present invention includes a first panel, a second panel, and a vibration actuator that vibrates the first panel and the second panel. The panel speaker includes an adhesive layer that bonds one surface of the first panel to one surface of the second panel, and a joint that bonds the other surface of the first panel to the vibration actuator. The adhesive layer includes first regions that are multiple parallel strip-shaped regions in a plan view of the first panel. The joint is disposed in a region sandwiched between the first regions in a plan view of the first panel. The adhesive layer further includes a second region between one of the two first regions adjacent to both sides of the joint and the joint in a plan view of the first panel.

[0008] In order to solve the above problems and achieve the object, a panel speaker according to the present invention includes a first panel, a second panel, and a vibration actuator that vibrates the first panel and the second panel. The panel speaker includes an adhesive layer that bonds one surface of the first panel to one surface of the second panel, and a joint that bonds the other surface of the first panel to the vibration actuator. The adhesive layer includes first regions that are multiple parallel strip-shaped regions in a plan view of the first panel. The joint is disposed in a region sandwiched between the first regions in a plan view of the first panel, and the distance to one of the two first regions adjacent to both sides of the joint is different from the distance to the other. Effect of the Invention

[0009] According to the present invention, it is possible to prevent a decrease in the sound pressure level in a panel speaker. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of the arrangement of panel speakers. [Diagram 2] FIG. 2 is a diagram showing the panel speaker and adhesive layer according to the first embodiment as viewed from the rear side. [Diagram 3] FIG. 3 is a cross-sectional view of a surface parallel to the xz plane, which passes through the vibration actuator of the panel speaker according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view of a plane parallel to the xz plane, passing through the vibration actuator of the display device according to the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of a surface parallel to the xz plane passing through the fixing portion of the holder according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a surface parallel to the xz plane passing through a fixing portion of a holder according to a modified example. [Figure 7] FIG. 7 is a diagram showing an example of frequency dependence of sound pressure of sound output from the panel speaker according to the first embodiment. [Figure 8] FIG. 8 is a diagram showing the panel speaker and adhesive layer according to the second embodiment as viewed from the rear side. [Figure 9] FIG. 9 is a cross-sectional view of a surface parallel to the xz plane, passing through the vibration actuator of the panel speaker according to the second embodiment. [Figure 10] FIG. 10 is a diagram showing an example of frequency dependence of sound pressure of sound output from the panel speaker according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the panel speaker disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiment described below.

[0012] 1 is a diagram showing an example of an arrangement of panel speakers. For example, a panel speaker 10 is provided in a display device that outputs video. In this case, the panel speaker may be called a display speaker.

[0013] As shown in Fig. 1, a display device equipped with a panel speaker 10 is provided on the ceiling between the front and rear seats of a vehicle 1. For example, the display device may be a flip-down type display device. The panel speaker 10 can output sound in the direction of the rear seats.

[0014] The aspects of the panel speaker 10 and the display device are not limited to those described in Fig. 1. The display device equipped with the panel speaker 10 may be a device that outputs route navigation (voice of the car navigation system), traffic information, and the like, to a passenger in the front seat (e.g., the driver).

[0015] [First embodiment] The configuration of the panel speaker 10a will be described with reference to Figures 2, 3 and 4. The panel speaker 10a can be arranged in the same manner as the panel speaker 10 in Figure 1.

[0016] Fig. 2 is a rear view of the panel speaker and adhesive layer according to the first embodiment. Fig. 3 is a cross-sectional view of a plane parallel to the xz plane that passes through the vibration actuator of the panel speaker according to the first embodiment. Fig. 4 is a cross-sectional view of a plane parallel to the xz plane that passes through the vibration actuator of the display device according to the first embodiment.

[0017] The panel speaker 10 a includes a vibration panel 11 , an adhesive layer 150 including a plurality of regions, and a vibration actuator 14 .

[0018] Here, the direction from left to right when the diaphragm panel 11 is viewed in plan from the rear side is defined as the x direction, the direction from bottom to top as the y direction, and the direction from the rear to the front (from the front to the back) as the z direction. The x direction, y direction, and z direction are perpendicular to each other.

[0019] The adhesive layer 150 includes a region 151, a region 152, a region 153, a region 154, and a region 155. The region 151, the region 152, the region 153, and the region 154 are strip-shaped regions parallel to each other. Thus, the adhesive layer 150 includes a plurality of parallel strip-shaped regions (an example of a first region) in a plan view of the first panel 111. The vibration actuator 14 is fixed to the vibration panel 11 via the holder 13 and the fixing portion 121, the fixing portion 122, the fixing portion 123, and the fixing portion 124. As a result, the vibration actuator 14 is in close contact with and bonded to the first panel 111. The portion where the vibration actuator 14 is in close contact with the first panel 111 is called a joint portion. The joint portion may be realized by a method other than the method described here. For example, the joint portion may be realized by a double-sided adhesive tape. The joint portion is disposed in a region sandwiched between at least any two of the band-shaped regions when the first panel 111 is viewed in plan.

[0020] 4, the diaphragm panel 11 is formed by bonding one surface of a first panel 111 and one surface of a second panel 112 with an adhesive layer 150. The diaphragm panel 11 is held by a housing 16. The other surface of the first panel 111 and the vibration actuator 14 are bonded to each other by a connecting portion.

[0021] The second panel 112 is a rectangular plate-like panel that serves as the diaphragm of the panel speaker 10a. Each side of the outer shape of the second panel 112 is parallel to the x-axis or y-axis. That is, two opposing sides of the rectangular outer shape of the second panel 112 are parallel to a first direction (x-direction), and the other two opposing sides are parallel to a second direction (y-direction) perpendicular to the first direction.

[0022] The second panel 112 is, for example, a flat glass panel or an OLED (Organic Light Emitting Diode) panel. The second panel 112 is bonded to the first panel 111 via an adhesive layer 150. The shape of the second panel 112 is not limited to a rectangle, and may be other shapes such as a square, a triangle, a polygon, an ellipse, or a circle.

[0023] The adhesive layer 150 is divided into a plurality of regions and arranged to bond the rear side of the second panel 112 and the front side of the first panel 111. In the example of FIG. 2, the adhesive layer 150 includes a region 151, a region 152, a region 153, a region 154, and a region 155.

[0024] Each region of the adhesive layer 150 is, for example, a double-sided adhesive tape. Each region of the adhesive layer 150 may be an adhesive. Each region is arranged at a different position so as not to overlap with each other in a plan view (when viewed from the front side or rear side, or when viewed from a direction perpendicular to the x direction and the y direction). The regions 151, 152, 153, and 154 are strip-shaped rectangles parallel to the y axis. The regions 151, 152, 153, and 154 are parallel to each other. The regions 151 and 154 have the same shape. The regions 152 and 153 have the same shape. The regions 151 and 152 may have the same shape. The width of the regions 151, 152, 153, and 154 in the y direction is larger than the width in the x direction. Here, the y direction is the longitudinal direction of the regions 151, 152, 153, and 154.

[0025] In the x direction, the distance between region 151 and the center of second panel 112 is equal to the distance between region 154 and the center of second panel 112. In addition, in a plan view, region 151 and region 154 are located at positions that are point-symmetric with respect to the center of second panel 112.

[0026] In the x direction, the distance between region 152 and the center of second panel 112 is equal to the distance between region 153 and the center of second panel 112. Furthermore, in a plan view, region 152 and region 153 are located at positions that are point-symmetric with respect to the center of second panel 112.

[0027] Moreover, the region 155 (an example of the second region) is disposed between any two of the regions 151, 152, 153, and 154. That is, the adhesive layer 150 includes the region 155 between one of two regions (for example, the region 152 and the region 153) adjacent to both sides of the joint portion in a plan view of the first panel 111 and the joint portion. In the example of FIG. 2, the region 155 is disposed between the region 152 and the region 153. The region 155 may have a different shape from any of the regions 151, 152, 153, and 154. For example, the region 155 is a rectangle smaller than the regions 151, 152, 153, and 154. In FIG. 2, the joint portion overlaps with a circle indicating the vibration actuator 140.

[0028] The same applies to the relationship between the center of the first panel 111 and each region. In the portions other than the respective regions of the adhesive layer 150 between the second panel 112 and the first panel 111, the second panel 112 and the first panel 111 are not joined. That is, the portions other than the respective regions of the adhesive layer 150 between the second panel 112 and the first panel 111 are, for example, voids. The portions other than the respective regions of the adhesive layer 150 between the second panel 112 and the first panel 111 are not the adhesive layer 150.

[0029] The number of regions of the adhesive layer 150 is not limited to four. The distance between an arbitrary position and a region is the distance between the arbitrary position and the center of the region. The center of a rectangle (rectangle) of the second panel 112 or the like is obtained, for example, as the intersection position of the diagonal lines of the rectangle. The center used here is not limited to the geometric center, but may be within a certain range including the geometric center. The certain range including the geometric center is, for example, within a circle having a radius of 2 cm centered on the geometric center, within a circle having a radius of 5% of the maximum width of the second panel 112 centered on the geometric center, or the like. The center of the second panel 112 or the like may be defined by the center of gravity, the inner center, the outer center, the intersection point of the center lines of the widths in two orthogonal directions, or the like. The regions 151, 152, 153, and 154 do not have to be parallel to the outer shape of the second panel 112.

[0030] The first panel 111 is disposed on the rear side of the second panel 112, between the second panel 112 and the vibration actuator 14. The first panel 111 is a rectangular panel having approximately the same size as the second panel 112 when viewed from the front side (in a plan view). The first panel 111 transmits the vibration of the vibration actuator 14 to the second panel 112. The first panel 111 is, for example, a metal plate such as an aluminum plate. In a plan view, the position of the center of the first panel 111 and the position of the center of the second panel 112 are the same.

[0031] Fig. 5 is a cross-sectional view of a surface parallel to the xz plane passing through the joint of the holder according to the first embodiment. The configuration of the fixing part 122 will be described with reference to Fig. 5. The fixing part 121, the fixing part 123, and the fixing part 124 may have the same configuration as the fixing part 122.

[0032] The fixing portion 122 is a screw, and fixes the holder 13 to a boss 1221 press-fitted into the first panel 111. The vibration actuator 14 is fixed to the first panel 111 via the holder 13. The vibration actuator 14 may also be fixed to the first panel 111 by double-sided tape or adhesive. The vibration actuator 14 and holder 13 may be collectively called an exciter.

[0033] The vibration actuator 14 is an electrodynamic vibration actuator that includes a voice coil that vibrates in a magnetic field created by a magnetic circuit and transmits the vibration of the voice coil to an object to be vibrated (for example, the first panel 111). In this way, the first embodiment can be implemented when an electrodynamic vibration actuator is used.

[0034] The vibration actuator 14 is disposed on the rear side of the first panel 111. The vibration actuator 14 is a circular plate-like member that is smaller than the first panel 111. The vibration actuator 14 may have a shape other than a circle. The vibration actuator 14 may be called a vibration unit.

[0035] As shown in FIG. 2, the vibration actuator 14 vibrates the first panel 111 around a position that is between two areas (areas 152 and 153) that sandwich area 155 when viewed in a plan view of the first panel 111, but does not overlap with area 155.

[0036] 3 is an arrow that points vertically from the center of vibration actuator 14 down to first panel 111. The tip of this arrow does not overlap with region 155.

[0037] 2, vibration actuator 14 does not overlap region 155. However, a portion of vibration actuator 14, excluding the center, may overlap region 155. In other words, vibration actuator 14 may be disposed in a position where its outline overlaps region 155 in a plan view.

[0038] Here, overlap means that parts of the two regions overlap with each other. However, in the first embodiment, the center of vibration actuator 14 is not included in the range of overlap with region 155. For example, a bow-shaped portion (a figure surrounded by a chord and an arc) of circular vibration actuator 14 may overlap with region 155.

[0039] 2, the vibration actuator 14 and the region 155 may be offset to the left of the diaphragm panel 11 (in the negative x direction) as long as the center of the vibration actuator 14 does not overlap with the region 152. In other words, the vibration actuator 14 and the region 155 are disposed at a position shifted to one side from the center of the first panel 111 in the longitudinal direction in a plan view.

[0040] In this way, as long as the constraint that the center of the vibration actuator 14 does not overlap with the area 155 is satisfied, the vibration actuator 14 can be freely positioned while improving the sound pressure.

[0041] (Modification) As shown in Fig. 6, the vibration actuator 14 may be a piezoelectric vibration actuator that includes a vibration plate 141 and a piezoelectric element bonded to at least one of the main surfaces of the vibration plate 141, and transmits flexural vibration generated in the vibration plate 141 by the stretching vibration of the piezoelectric element to an object to be vibrated. Fig. 6 is a cross-sectional view of a surface parallel to the xz plane passing through the fixing part of the holder according to the modified example. In this way, the first embodiment can be implemented when a piezoelectric vibration actuator is used.

[0042] Fig. 7 is a diagram showing an example of frequency dependency of sound pressure of sound output from the panel speaker according to the first embodiment. The horizontal axis of the graph in Fig. 7 is frequency, and the vertical axis is sound pressure. The sound pressure on the vertical axis is not an absolute sound pressure value, but a relative value with respect to a reference value.

[0043] For comparison, an example of a panel speaker of the prior art is also shown in Fig. 7. In the prior art, the center of vibration actuator 14 is located at the center of first panel 111 (on the dashed line in Fig. 2) in a plan view, and the center of region 155 is arranged at the same position as the center of vibration actuator 14.

[0044] 7, in the first embodiment, sound pressure is improved compared to the conventional technology, particularly in the high frequency range of 4 kHz or more. This is believed to be because the position of area 155 in the first embodiment is changed from that in the conventional technology, which relaxes the constraint directly below vibration actuator 14 (first panel 111 side), thereby suppressing vibration attenuation.

[0045] [Second embodiment] As explained in the first embodiment, the sound pressure of the panel speaker was improved by ensuring that the center of the vibration actuator 14 and the area of ​​the adhesive layer do not overlap in a plan view. On the other hand, it is believed that arranging the vibration actuator 14 in an asymmetric position with respect to the adhesive layer also contributes to improving the sound pressure.

[0046] Fig. 8 is a rear view of the panel speaker and adhesive layer according to the second embodiment. Fig. 9 is a cross-sectional view of a plane parallel to the xz plane passing through the vibration actuator of the panel speaker according to the second embodiment. The panel speaker 10b can be arranged in the same manner as the panel speaker 10 in Fig. 1.

[0047] 8 and 9, in the second embodiment, the adhesive layer 150 of the panel speaker 10b does not include the region 155. However, even in the second embodiment, the region 155 may be disposed at a position that does not overlap with the center of the vibration actuator 14.

[0048] As shown in FIG. 8, the joint is disposed in a region sandwiched between two regions (here, regions 152 and 153) in a plan view of the first panel 111, and the distance to one of the two regions adjacent to both sides of the joint is different from the distance to the other. Note that in FIG. 8, the joint overlaps with the circle representing the vibration actuator 140. d1 is the distance from the center of the joint to the center of region 152. d2 is the distance from the center of the joint to the center of region 153. In the second embodiment, d1 and d2 are different.

[0049] 8, the center of vibration actuator 14 does not overlap region 152. However, a portion of the region of vibration actuator 14 excluding the center may overlap region 152. In other words, vibration actuator 14 may be disposed in a position where its outline overlaps region 152 in a plan view.

[0050] In this way, as long as the constraint that the position of vibration actuator 14 is asymmetric with respect to area 152 and area 153 is satisfied, vibration actuator 14 can be freely positioned while improving sound pressure.

[0051] 10 is a diagram showing an example of frequency dependence of sound pressure of sound output from the panel speaker according to the second embodiment. The horizontal and vertical axes of the graph in FIG.

[0052] As shown in FIG. 10, in the second embodiment, the sound pressure is improved compared to the conventional technology, particularly in the high frequency range of 4 kHz or more.

[0053] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0054] 1 vehicle 10, 10a, 10b Panel speaker 11 Vibration Panel 13 Holder 14 Vibration Actuator 16 Case 111 First Panel 112 Second Panel 121, 122, 123, 124 Fixed part 150 Adhesive layer 151, 152, 153, 154, 155 area

Claims

1. A first panel; A second panel; a vibration actuator that vibrates the first panel and the second panel; an adhesive layer that bonds one surface of the first panel and one surface of the second panel; a coupling portion that couples the other surface of the first panel to the vibration actuator, The adhesive layer includes a first region that is a plurality of parallel strip-shaped regions in a plan view of the first panel, the coupling portion is disposed in a region sandwiched between the first regions in a plan view of the first panel, The adhesive layer further includes a second region between one of the first regions adjacent to both sides of the joint portion in a plan view of the first panel and the joint portion. Panel speaker.

2. The vibration actuator is disposed at a position where an outer shape of the vibration actuator overlaps with the second region in the plan view.

2. A panel speaker according to claim 1.

3. The vibration actuator and the second region are disposed at a position shifted to one side from a center in a longitudinal direction of the first panel in the plan view.

2. A panel speaker according to claim 1.

4. A first panel; A second panel; a vibration actuator that vibrates the first panel and the second panel; an adhesive layer that bonds one surface of the first panel and one surface of the second panel; a coupling portion that couples the other surface of the first panel to the vibration actuator, The adhesive layer includes a first region that is a plurality of parallel strip-shaped regions in a plan view of the first panel, The joint portion is disposed in a region sandwiched between the first regions in a plan view of the first panel, and a distance to one of the two first regions adjacent to both sides of the joint portion is different from a distance to the other of the two first regions. Panel speaker.

5. The vibration actuator is disposed at a position where an outer shape of the vibration actuator overlaps with the first region in the plan view.

3. A panel speaker according to claim 2.

6. The vibration actuator is an electrodynamic vibration actuator that includes a voice coil that vibrates in a magnetic field created by a magnetic circuit and transmits the vibration of the voice coil to an object to be vibrated.

6. A panel speaker according to claim 1.

7. The vibration actuator is a piezoelectric vibration actuator that includes a vibration plate and a piezoelectric element bonded to at least one of the main surfaces of the vibration plate, and transmits bending vibrations generated in the vibration plate by the stretching vibrations of the piezoelectric element to an object to be vibrated.

6. A panel speaker according to claim 1.

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