Panel speaker

Abstract

To provide a panel speaker which vibrates efficiently.SOLUTION: A panel speaker has: a panel; a vibration actuator which vibrates the panel; a bracket disposed between the vibration actuator and the panel; a spacer which faces the bracket across the vibration actuator; and a screw which penetrates the spacer, the vibration actuator, and the bracket so as to fasten the spacer, the vibration actuator, and the bracket to the panel. The bracket and the spacer are both insulators so that the vibration actuator may be electrically insulated from the panel.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] There is a display speaker that makes a display into a speaker by vibrating a display panel of the display with an actuator (vibration actuator) using a piezoelectric element. In the display speaker, the vibration actuator is attached to the back surface of the display panel (vibration panel). Thereby, the vibration of the vibration actuator can be transmitted to the display panel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The vibration actuator is attached to the display panel, for example, by a metal screw. By using a metal screw, the vibration actuator is firmly fixed to the display panel. However, when the vibration actuator and the display panel are short-circuited by using a metal screw, there is a problem that the vibration actuator stops vibrating.

[0005] An object of the present invention is to provide a panel speaker that vibrates efficiently.

Means for Solving the Problems

[0006] To solve the above problems, the present invention employs the following means. That is, the first aspect is a panel, A vibration actuator that vibrates the panel, A bracket disposed between the vibration actuator and the panel, A spacer facing the bracket with the vibration actuator interposed therebetween, A screw that penetrates the spacer, the vibration actuator, and the bracket and fastens the spacer, the vibration actuator, and the bracket to the panel, Both the bracket and the spacer are insulators, and the vibration actuator is electrically insulated from the panel, is a panel speaker.

Advantages of the Invention

[0007] According to the present invention, a panel speaker that vibrates efficiently can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of the embodiments.

[0010] Here, a case where a vibration actuator is provided on a display panel (vibration panel) of a display and the display functions as a display speaker will be described. A display speaker is a device that outputs (emits) sound waves from a display panel by vibrating the display panel with a vibration actuator (actuator). A display speaker is an example of a panel speaker. A panel speaker is a speaker that outputs sound by vibrating a flat panel such as a display panel.

[0011] 〈Embodiment〉 (Configuration example) FIG. 1 is a diagram showing a configuration example of a display speaker 10 according to this embodiment. FIG. 1 is a side view of the display speaker 10 as viewed from the side. The display speaker 10 includes a display panel 100, a bracket 200, a vibration actuator 300, a spacer 400, and a screw 500.

[0012] FIG. 2 is a top view of the display speaker 10 as viewed from above. In FIG. 2, the spacer 400 and the vibration actuator 300 are shown, and the screw 500 and the like are omitted.

[0013] FIG. 3 is a cross-sectional view taken along line AA of the display speaker 10 in FIG. 2. FIG. 4 is an exploded perspective view of the bracket 200, the vibration actuator 300, and the spacer 400. In the display speaker 10, the bracket 200, the vibration actuator 300, and the spacer 400 are stacked in this order from the display panel 100 side.

[0014] The display panel 100 includes a main body portion 110, a bracket attachment portion 120, and a screw attachment portion 130. The bracket 200 includes a main body portion 210, leg portions 220, and a protrusion portion 230. The vibration actuator 300 includes a diaphragm 310, a piezoelectric element 320 attached to the surface of the diaphragm 310 on the display panel side (referred to as the first surface), and a piezoelectric element 330 attached to the surface of the diaphragm 310 opposite to the first surface (referred to as the second surface). The display speaker 10 is arranged in the order of the display panel 100, the bracket 200, the vibration actuator 300, and the spacer 400, and is fixed by screws 500. A plurality of brackets 200, vibration actuators 300, spacers 400, and screws 500 may be attached to one display panel 100. Here, the direction from right to left in FIG. 1 is the x direction, the direction from the front surface to the back surface of the paper of FIG. 1 is the y direction, and the direction from bottom to top in FIG. 1 (the direction from the display panel 100 to the vibration actuator 300) is the z direction. The positional relationship between the display speaker 10 and the x, y, and z directions is the same in other figures. It is assumed that the screws 500 are attached parallel to the z direction. The display panel 100 is an example of a panel.

[0015] The display panel 100 includes a main body portion 110, a bracket attachment portion 120, and a screw attachment portion 130. The display panel 100 is made of a conductive metal and is grounded. The main body portion 110 is a plate-like member that serves as the diaphragm of the display speaker 10. The bracket attachment portion 120 is a recess where the leg portions 220 of the bracket 200 are attached. The shape of the bracket attachment portion 120 is a hole that matches the shape of the leg portions 220 of the bracket 200. By fitting the leg portions 220 of the bracket 200 into the bracket attachment portion 120, the bracket 200 is prevented from rotating around the z direction. The screw attachment portion 130 is a fixed shaft for fixing the screw 500. The screw attachment portion 130 has a screw hole for fixing the screw 500. The screw 500 is attached parallel to the z direction by the screw attachment portion 13 0 protrudes from the plane on the vibration actuator 300 side of the main body 110 toward the vibration actuator 300 side. The screw mounting portion 130 may not protrude from the plane on the vibration actuator 300 side of the main body 110. The display panel 100 is a display panel included in a liquid crystal display, an organic EL (Electro-Luminescence) display, or the like.

[0016] The bracket 200 includes a main body portion 210, leg portions 220, and protrusion portions 230. The bracket 200 may include a plurality of leg portions 220 and a plurality of protrusion portions 230. In an example such as FIG. 1, the bracket 200 has two leg portions 220 and two protrusion portions 230. The bracket 200 transmits the vibration of the vibration actuator 300 to the display panel 100. The bracket 200 is an insulator. The bracket 200 is, for example, a resin. The main body portion 210 of the bracket 200 is, for example, a columnar object and has an upper surface and a lower surface that are substantially parallel to each other. The upper surface is in contact with the vibration actuator 300, and the lower surface is in contact with the display panel 100. The shape of the upper surface and the shape of the lower surface may be different. The main body portion 210 has a screw through-hole through which a screw 500 passes between the upper surface and the lower surface. The diameter of the screw through-hole is larger than the diameter of the axis of the screw 500 on the vibration actuator 300 side and is larger than the outer diameter of the screw attachment portion 130 of the display panel 100 on the display panel 100 side. The leg portions 220 extend from the lower surface of the main body portion 210 in the direction of the display panel 100. The leg portions 220 have a shape that fits into the bracket attachment portion 120 of the display panel 100. The leg portions 220 are, for example, columnar shapes such as cylinders or square prisms. The protrusion portions 230 extend from the upper surface of the main body portion 210 in the direction of the vibration actuator 300. The protrusion portions 230 are, for example, columnar shapes such as cylinders or square prisms. The protrusion portions 230 pass through the through-hole for the protrusion portion of the vibration plate 310 of the vibration actuator 300 and are fitted into the through-hole for the protrusion portion of the spacer 400 corresponding to the protrusion portions 230. In an example such as FIG. 1, the distance from each protrusion portion 230 to the screw through-hole (center) is equal. Also, in an example such as FIG. 1, the two protrusion portions 230 and the screw through-hole are present on a straight line parallel to the x-direction on the upper surface of the main body portion 210 of the bracket 200. That is, the two protrusion portions 230 are provided at symmetric positions around the screw 500. The vibration plate 310 of the vibration actuator 300 is coupled to the display panel 100 via the bracket 200. The shape of the upper surface of the main body portion 210 is, for example, rectangular.

[0017] The diaphragm 310 of the vibration actuator 300 is a rectangular plate-like member having a front surface (first surface) and a back surface (second surface) in a direction orthogonal to the thickness direction. The shape of the diaphragm 310 in plan view may be circular or elliptical. Also, the shape of the diaphragm 310 in plan view may be other shapes as long as it is symmetric about the left and right and symmetric about the top and bottom. The front surface is substantially parallel to the back surface. Further, the central portion of the diaphragm 310 (the portion including the center of the first surface, the central portion in plan view) is exposed by the opening of the piezoelectric element 320. Here, when the shape of the diaphragm 310 is rectangular, the center of the first surface (second surface) of the diaphragm 310 is the intersection of the two diagonals of the rectangle. Also, when the shape of the diaphragm 310 is circular or elliptical, the center of the first surface (second surface) of the diaphragm 310 is the center of the circle or ellipse. Even when the shape of the diaphragm 310 is other shapes, the center of the first surface (second surface) of the diaphragm 310 can be defined by, for example, the center of gravity. The diaphragm 310 is a conductor (for example, metal). Also, the diaphragm 310 is arranged such that the surface of the diaphragm 310 is substantially parallel to the back surface of the display panel 100.

[0018] The piezoelectric elements 320 and 330 are elements whose shape deforms according to the voltage when a voltage is applied. The piezoelectric elements 320 and 330 are elements made of a plate-like material such as ceramic that exhibits the piezoelectric effect. Electrodes for applying a voltage are attached to the piezoelectric elements 320 and 330. The piezoelectric element 320 is attached to the first surface of the diaphragm 310. The piezoelectric element 330 is attached to the second surface of the diaphragm 310. Since the diaphragm 310 is a conductor, the diaphragm 310 serves as one electrode of the piezoelectric element 320 and one electrode of the piezoelectric element 330. The piezoelectric element 320 has an opening such that the central portion of the diaphragm 310 is exposed when viewed from the first surface side. Also In addition, a screw through-hole through which the screw 500 passes is present in the central portion of the diaphragm 310. The diameter of the screw through-hole is larger than the diameter of the shaft of the screw 500 so as not to come into contact with the screw 500. Since the screw 500 and the diaphragm 310 do not come into contact with each other, the diaphragm 310 and the display panel 100 do not electrically short-circuit (do not short). Further, a protrusion through-hole through which the protrusion 230 of the bracket 200 passes is present around the screw through-hole in the central portion of the diaphragm 310. The diameter of the protrusion through-hole is larger than the diameter of the protrusion 230. The protrusion 230 and the protrusion through-hole may come into contact with each other. The position of the protrusion through-hole can be adjusted according to the position of the protrusion 230 of the bracket 200. The diaphragm 310 has a portion (exposed portion) exposed at the central portion of the first surface of the diaphragm 310 by the opening of the piezoelectric element 320. The upper surface of the main body portion 210 of the bracket 200 is in contact with the opening. The opening is larger than the upper surface of the main body portion 210 of the bracket 200. At this time, the piezoelectric element 320 and the bracket 200 do not come into contact with each other. The piezoelectric element 330 has an opening so that the central portion of the diaphragm 310 is exposed when viewed from the second surface side. The diaphragm 310 has a portion (exposed portion) exposed at the central portion of the second surface of the diaphragm 310 by the opening of the piezoelectric element 330. The screw through-hole and the protrusion through-hole are present in the exposed portion. In an example such as FIG. 1, the distances from each protrusion through-hole to the screw through-hole (center) are equal. Also, in an example such as FIG. 1, the two protrusion through-holes and the screw through-hole are present on a straight line parallel to the x direction. That is, the two protrusion through-holes are provided at symmetric positions with the screw 500 as the center. The lower surface of the spacer 400 is in contact with the opening. The opening is larger than the lower surface of the spacer 400. At this time, the piezoelectric element 330 and the spacer 400 do not come into contact with each other. The piezoelectric element 330 does not have to be attached to the diaphragm 310. The first surface and the second surface are on a plane parallel to the xy plane.

[0019] The opening of the piezoelectric element 320 may be rectangular (square), or circular, elliptical, etc. according to the shape of the bracket 200. In order to increase the area of the piezoelectric element 320, it is desirable to make the size of the opening of the piezoelectric element 320 as small as possible. By increasing the area of the piezoelectric element 320, the output (maximum output) of the display speaker 10 can be made larger. Also, when viewing the vibration actuator 300 from the first surface side, it is desirable that the outer end of the piezoelectric element 320 is inside the end of the diaphragm 310. If the outer end of the piezoelectric element 320 is outside the end of the diaphragm 310, the piezoelectric element 320 is likely to be damaged. The same applies to the piezoelectric element 330 attached to the second surface of the diaphragm 310.

[0020] The spacer 400 is a member sandwiched between the head of the screw 500 and the diaphragm 310 of the vibration actuator 300. The spacer 400 is an insulator. The spacer 400 is, for example, resin. The material of the spacer 400 is preferably the same as the material of the bracket 200. Also, it is preferable that the elastic modulus of the spacer 400 is equal to the elastic modulus of the bracket 200. The spacer 400 is, for example, a columnar object and has an upper surface and a lower surface that are substantially parallel to each other. The upper surface contacts the lower part of the head of the screw 500, and the lower surface contacts the diaphragm 310. The area of the upper surface and the area of the lower surface may be different. The spacer 400 has a screw through-hole through which the screw 500 passes between the upper surface and the lower surface. The diameter of the screw through-hole is smaller than the diameter of the head of the screw 500 and larger than the diameter of the shaft of the screw 500. The diameter of the screw through-hole of the spacer 400 and the diameter of the screw through-hole of the bracket 200 are preferably equal.

[0021] Further, the spacer 400 has, on its lower surface, a hole for the protrusion through which the protrusion 230 of the bracket 200 passes. The hole for the protrusion may be a through hole penetrating from the lower surface to the upper surface, or a non-through hole that does not penetrate. The hole for the protrusion is a hole into which the protrusion 230 can be fitted. The diameter of the hole for the protrusion is larger than the diameter of the protrusion 230. The protrusion 230 and the hole for the protrusion may be in contact. The position of the hole for the protrusion is adjusted according to the position of the protrusion 230 of the bracket 200. Here, it is assumed that the bracket 200 has the protrusion 230 on the upper surface of the main body portion 210, and the spacer 400 has a hole for the protrusion corresponding to the protrusion 230 on its lower surface. However, the lower surface of the spacer 400 may have a protrusion, and the upper surface of the main body portion 210 of the bracket 200 may have a hole for the protrusion. Also, each of the upper surface of the main body portion 210 of the bracket 200 and the lower surface of the spacer 400 may have a protrusion and a hole for the protrusion. In an example such as FIG. 1, the distances from each hole for the protrusion to the screw through hole (center) are equal. Also, in an example such as FIG. 1, the two holes for the protrusion and the screw through hole are present on a straight line parallel to the x direction. That is, the two holes for the protrusion are provided at symmetric positions around the screw 500.

[0022] The screw 500 passes through the screw through hole of the spacer 400, the screw through hole of the diaphragm 310 of the vibration actuator 300, and the screw through hole of the main body portion 210 of the bracket 200 in sequence, and is fastened to the screw hole of the screw attachment portion 130 of the display panel 100. Thereby, the spacer 400, the vibration actuator 300, and the bracket 200 are fixed to the display panel 100. Also, since the screw 500 does not contact the diaphragm 310 and the bracket 200 is an insulator, the display panel 100 and the diaphragm 310 are not electrically short-circuited. Thereby, even when the diaphragm 310 is not grounded, a voltage is normally applied to the piezoelectric elements 320 and 330. Bolts and nuts may be used instead of the screw 500.

[0023] Here, assume that a flexural vibration occurs in which the x-direction of the diaphragm 310 is bowed in the z-direction. That is, assume that a flexural vibration occurs in which the x-direction of the diaphragm 310 is bowed in the z-direction due to the voltages applied to the piezoelectric elements 320 and 330. At this time, the flexural vibration propagates in the x-direction of the diaphragm 310. At this time, as shown in FIG. 1 and the like, a plurality of protrusions 230 are provided in a direction along the direction in which the flexural vibration of the diaphragm 310 propagates. The same applies to the through-holes for the protrusions of the diaphragm 310 and the holes for the protrusions of the spacer 400. That is, the protrusions 230 of the bracket 200, the through-holes for the protrusions of the diaphragm 310 of the vibration actuator 300, and the holes for the protrusions of the spacer 400 exist on a straight line parallel to the x-direction passing through the center of the screw 500 when viewed from the z-direction. By being fixed at more positions in the propagation direction of the flexural vibration, the vibration modes are dispersed, and the vibration of the diaphragm 310 can be transmitted to the display panel 100 more efficiently over a wide band. In the example of FIG. 1 and the like, the distances from the screw through-holes of the two protrusions 230 are equal. Thereby, the vibration actuator 300 can vibrate the display panel 100 evenly. In the example of FIG. 1 and the like, two protrusions 230, two through-holes for the protrusions, and two holes for the protrusions are provided, but the vibration actuator 300 may be fixed by two or more protrusions 230, two or more through-holes for the protrusions, and two or more holes for the protrusions. The protrusions 230 of the bracket 200 pass through the through-holes for the protrusions of the diaphragm 310 and are fitted into the holes for the protrusions of the spacer 400. By fixing the vibration actuator 300 with the protrusions 230 and the like, it is possible to suppress the rotation of the vibration actuator 300 about the z-direction (screw 500) as the rotation axis. Also, by arranging two protrusions 230 and the like such that the distances from the center of the screw 500 are equal on a straight line parallel to the x-direction passing through the center of the screw 500 when viewed from the z-direction, the vibration of the diaphragm 310 can be transmitted to the display panel 100 evenly and efficiently.

[0024] (Operations and Effects of the Embodiment) The display speaker 10 of this embodiment includes a display panel 100, a bracket 200, a vibration actuator 300, a spacer 400, and a screw 500. The vibration actuator 300 includes a diaphragm 310, a piezoelectric element 320, and a piezoelectric element 330. The bracket 200, the vibration actuator 300, and the spacer 400 are fixed to the display panel 100 by the screw 500. The screw 500 is passed through the screw through-hole of the bracket 200, the screw through-hole of the vibration actuator 300, and the screw through-hole of the spacer 400. By preventing the diaphragm 310 from contacting the screw 500, an electrical short circuit between the display panel 100 and the diaphragm 310 can be avoided. The upper surface of the bracket 200 and the lower surface of the spacer 400 face each other with the diaphragm 310 interposed therebetween. Also, the bracket 200 has a protrusion 23 0. The protrusion 230 passes through the through-hole for protrusion of the diaphragm 310 and is fitted into the hole for protrusion on the lower surface of the spacer 400. Thereby, rotation of the vibration actuator 300 around the axis of the screw 500 can be suppressed. That is, the position of the vibration actuator 300 can be reliably fixed. Also, the positions of the two protrusions 230 of the bracket 200 are equal in distance from the screw through-hole (center position). The protrusion 230 of the bracket 200, the through-hole for protrusion of the diaphragm 310 of the vibration actuator 300, and the hole for protrusion of the spacer 400 are located on a straight line parallel to the x-direction passing through the center of the screw 500 when viewed from the z-direction. Thereby, the vibration actuator 300 can vibrate evenly. The display speaker 10 can vibrate the display speaker 10 efficiently when the vibration actuator 300 vibrates evenly. Also, the display speaker 10 can output high-quality sound when the vibration actuator 300 vibrates evenly.

[0025] The embodiments of the present invention have been described above, but these are merely examples, and the present invention is not limited thereto. Various modifications based on the knowledge of those skilled in the art are possible without departing from the spirit of the claims.

Explanation of Reference Numerals

[0026] 10 displacement speaker 100 display panel 110 main body part 120 bracket mounting part 130 screw mounting part 200 bracket 210 main body part 220 leg part 230 protrusion part 300 vibration actuator 310 diaphragm 320 piezoelectric element 330 piezoelectric element 400 spacer 500 screw

Claims

1. a panel, a vibration actuator for vibrating the panel, a bracket disposed between the vibration actuator and the panel, a spacer facing the bracket with the vibration actuator interposed therebetween, a screw that passes through the spacer, the vibration actuator, and the bracket and fastens the spacer, the vibration actuator, and the bracket to the panel, both the bracket and the spacer are insulators, and the vibration actuator is electrically insulated from the panel, one of the bracket and the spacer has a protrusion, the other of the bracket and the spacer has a hole for the protrusion into which the protrusion is fitted, and the vibration actuator has a through-hole for the protrusion through which the protrusion passes, a panel speaker.

2. a panel, a vibration actuator for vibrating the panel, a bracket disposed between the vibration actuator and the panel, a spacer facing the bracket with the vibration actuator interposed therebetween, a screw that passes through the spacer, the vibration actuator, and the bracket and fastens the spacer, the vibration actuator, and the bracket to the panel, both the bracket and the spacer are insulators, and the vibration actuator is electrically insulated from the panel, one of the bracket and the spacer has two protrusions, the other of the bracket and the spacer has two holes for the protrusions into which the two protrusions are respectively fitted, and the vibration actuator has two through-holes for the protrusions through which the protrusions pass, the two protrusions, the two holes for the protrusions, and the two through-holes for the protrusions are respectively provided in a direction along the propagation direction of the flexural vibration of the vibration actuator and at symmetric positions about the screw, a panel speaker.

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