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 be fastened to the panel. The vibration actuator is fastened to the panel with the screw in a state sandwiched between the bracket and the spacer.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 by, for example, a metal screw. By using a metal screw, the vibration actuator is firmly fixed to the display panel. However, in the conventional attachment structure of the actuator, there is a problem that the efficiency of vibrating the display panel is not sufficient.

[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 is fastened to the panel, wherein the vibration actuator is fastened to the panel by the screw while being sandwiched between the bracket and the spacer, 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

Modes 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 the 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 the present 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 mounting portion 120, and a screw mounting portion 130. The bracket 200 includes a main body portion 210 and leg portions 220. 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. The leg portion 220 is an example of a protrusion.

[0015] The display panel 100 is made of 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 mounting portion 120 is a recess where the leg portions 220 of the bracket 200 are mounted. The shape of the bracket mounting 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 mounting portion 120, the bracket 200 is prevented from rotating around the z direction. The bracket mounting portion 120 protrudes from the plane of the main body portion 110 on the vibration actuator 300 side to the opposite side of the vibration actuator 300 side. The bracket mounting portion 120 is an example of a hole. The bracket 200 has a hole like the bracket mounting portion 120, and the display panel 100 has a protrusion like the leg portion 220 There may be a starting part, and the hole and the protrusion may be fitted together. The screw mounting part 130 is a fixed shaft for fixing the screw 500. The screw mounting part 130 has a screw hole for fixing the screw 500. The screw 500 is mounted parallel to the z direction by the screw mounting part 130. The screw mounting part 130 protrudes from the plane of the main body part 110 on the vibration actuator 300 side toward the vibration actuator 300. The screw mounting part 130 may not protrude from the plane of the main body part 110 on the vibration actuator 300 side. The display panel 100 is a display panel included in a liquid crystal display, an organic EL (Electro-Luminescence) display, etc.

[0016] The bracket 200 includes a main body part 210 and leg parts 220. 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, resin. The main body part 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 part 210 has a through hole through which the screw 500 passes between the upper surface and the lower surface. The diameter of the through hole is larger than the diameter of the axis of the screw 500 on the vibration actuator 300 side and larger than the outer diameter of the screw mounting part 130 of the display panel 100 on the display panel 100 side. The leg parts 220 extend from the lower surface of the main body part 210 in the direction of the display panel 100. The leg parts 220 have a shape that can be fitted into the bracket mounting part 120 of the display panel 100. The leg parts 220 are, for example, columnar shapes such as a cylinder or a square prism. 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 part 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. Further, if the shape of the diaphragm 310 in plan view is symmetric about the left and right and symmetric about the top and bottom, it may be other shapes. The front surface is substantially parallel to the back surface. Also, 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 if 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 so that the surface of the diaphragm 310 is substantially parallel to the back surface of the display panel 100.

[0018] Piezoelectric elements 320 and 330 are elements whose shape deforms in response to an applied voltage. The piezoelectric elements 320 and 330 are elements made of a plate-like material such as a 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 so that the central portion of the diaphragm 310 is exposed when viewed from the first surface side. Also, there is a through-hole in the central portion of the diaphragm 310 through which the screw 500 passes. The diameter of the through-hole is larger than the diameter of the axis of the screw 500 so as not to contact the screw 500. Since the screw 500 does not contact the diaphragm 310, the diaphragm 310 and the display panel 100 are not electrically short-circuited. That is, the diaphragm 310 and the display panel 100 are electrically insulated. The diaphragm 310 has a portion (exposed portion) that is exposed at the central portion of the first surface of the diaphragm 310 due to the opening of the piezoelectric element 320. The upper surface of the main body portion 210 of the bracket 200 contacts 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 contact 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) that is exposed at the central portion of the second surface of the diaphragm 310 due to the opening of the piezoelectric element 330. The lower surface of the spacer 400 contacts 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 contact each other. The piezoelectric element 330 does not necessarily have to be attached to the diaphragm 310. The first surface and the second surface are on a plane parallel to the xy plane. The upper surface of the main body portion 210 of the bracket 200 contacts. 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 contact 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) that is exposed at the central portion of the second surface of the diaphragm 310 due to the opening of the piezoelectric element 330. The lower surface of the spacer 400 contacts 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 contact each other. The piezoelectric element 330 does not necessarily 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 circular, elliptical, etc., in accordance with the shape of the bracket 200, even if it is rectangular (square). 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 the vibration actuator 300 is viewed 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. It is preferable that the material of the spacer 400 is 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 through hole through which the screw 500 passes between the upper surface and the lower surface. The diameter of the 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. It is preferable that the diameter of the through hole of the spacer 400 is equal to the diameter of the through hole of the bracket 200.

[0021] Here, the shape of the lower surface of the spacer 400 in plan view is the same as the shape of the upper surface of the bracket 200 in plan view. Also, when the display speaker 10 is viewed from the z direction, the position of the lower surface of the spacer 400 coincides with the position of the upper surface of the bracket 200. By making the shape of the area in contact with the diaphragm 310 the same in the spacer 400 and the bracket 200 and opposing the bracket 200 and the spacer 400 with the diaphragm 310 therebetween, the vibration of the vibration actuator can be made uniform. Further, by making the material of the bracket 200 the same as the material of the spacer 400, the vibration of the vibration actuator can be made even more uniform.

[0022] The screw 500 passes through the through-hole of the spacer 400, the through-hole of the diaphragm 310 of the vibration actuator 300, and the through-hole of the main body portion 210 of the bracket 200 in order, 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. That is, the display panel 100 and the diaphragm 310 are electrically insulated. Thereby, even when the diaphragm 310 is not grounded, a voltage is normally applied to the piezoelectric elements 320 and 330. A bolt and a nut may be used instead of the screw 500.

[0023] Here, assume that a bending vibration in which the x direction of the diaphragm 310 is bowed in the z direction is occurring. That is, due to the voltage applied to the piezoelectric elements 320 and 330, the x direction of the diaphragm 310 Suppose that a flexural vibration occurs in which the shape becomes arcuate in the z direction. 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 leg portions 220 and a plurality of bracket attachment portions 120 are provided in the direction along the direction in which the flexural vibration of the diaphragm 310 propagates. That is, the leg portion 220 of the bracket 200 and the bracket attachment portion 120 of the display panel 100 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 leg portions 220 are equal. Thereby, the vibration actuator 300 can vibrate the display panel 100 evenly. In the example of FIG. 1 and the like, two leg portions 220 and two bracket attachment portions 120 are provided, but the bracket 200 may be fixed to the display panel 100 by two or more leg portions 220 and two or more bracket attachment portions 120. Further, when viewed from the z direction, by arranging two leg portions 220 or the like so 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, the vibration of the diaphragm 310 can be evenly and efficiently transmitted to the display panel 100.

[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 through holes of the bracket 200, the vibration actuator 300, and 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. The upper surface of the bracket 200 and the lower surface of the spacer 400 have the same outer shape. The material of the bracket 200 is the same as that of the spacer 400. 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 Display speaker 100 Display panel 110 Main body part 120 Bracket attachment part 130 Screw attachment part 200 Bracket 210 Main body part 220 Leg part 300 Vibration actuator 310 Diaphragm 320 Piezoelectric element 330 Piezoelectric element 400 Spacer 500 Screw

Claims

1. 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, having a screw that passes through the spacer, the vibration actuator, and the bracket and is fastened to the panel, wherein the vibration actuator is fastened to the panel by the screw while being sandwiched between the bracket and the spacer, one of the bracket and the panel has a protrusion, and the other of the bracket and the panel has a hole into which the protrusion fits, a panel speaker.

2. 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, having a screw that passes through the spacer, the vibration actuator, and the bracket and is fastened to the panel, wherein the vibration actuator is fastened to the panel by the screw while being sandwiched between the bracket and the spacer, one of the bracket and the panel has two protrusions, and the other of the bracket and the panel has two holes into which the two protrusions fit, wherein the two protrusions and the two holes are provided in a direction along the propagation direction of the bending vibration of the vibration actuator and are provided at symmetric positions about the screw, a panel speaker.

3. The outer shape of the surface of the bracket that contacts the vibration actuator is the same as the outer shape of the surface of the spacer that contacts the vibration actuator, The panel speaker according to claim 1 or 2.

4. The material of the bracket is the same as the material of the spacer, The panel speaker according to claim 1 or 2.

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