JP2005080044A - Flat board loudspeaker unit and electric apparatus with the unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a frame thinner in thickness than heretofore in an electric apparatus with a flat board loudspeaker. <P>SOLUTION: This flat board loudspeaker unit is provided with a transparent diaphragm 2 for outputting sound, a vibration supply part 4 for vibrating the diaphragm 2 and a display device 3 located inside the diaphragm 2 to display information in the frame. The diaphragm 2 and the display device 3 are overlapped through a gap and an image on the display device 3 is visually recognized through the diaphragm 2 . The circumferential part of the diaphragm 2 is placed on and fixed to the frame 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a planar speaker unit and an electric device such as a mobile phone including the planar speaker unit.

The following is well known as a flat speaker arranged on the front surface of a display device such as a mobile phone. 10 is a perspective view in which a flat speaker is arranged on the front surface of the display device, FIG. 11 is a cross-sectional view of the flat speaker in FIG. 10 cut along a plane including the line BB, and FIG. It is an enlarged view of C section (refer to patent documents 1).
A conventional planar speaker is composed of a transparent diaphragm (2) and a vibration supply section (4), and a vibration supply for vibrating the diaphragm (2) corresponding to one end of the diaphragm (2). A part (4) is provided. The vibration supply unit (4) includes a magnet member (41) and a coil (40) provided on the diaphragm (2). The magnet member (41) includes a case (44), a yoke (43), and a magnet (42) covered with the yoke (43).
When an electric signal based on the audio signal is passed through the coil (40), lines of magnetic force are generated from the coil (40). The magnetic lines of force act on the magnetic field of the magnets (42), (42) and (42), and the diaphragm (2) vibrates up and down. Thereby, a sound is output from the diaphragm (2).
The above flat speaker has a transparent diaphragm (2) attached to a casing (8) of an electric device such as a mobile phone via a cushion (19), and a liquid crystal is provided below the diaphragm (2). A display device (3) which is a panel is provided. The casing (8) has a window hole (18) facing the diaphragm (2) and the display device (3). Thereby, the image of the display device (3) can be visually recognized through the diaphragm (2).
Utility model registration 3078022 (Fig. 2)

At present, thinning of the housing (8) is required for electrical devices such as mobile phones. In order to reduce the thickness of the housing (8), it is preferable that the distance between the diaphragm (2) and the display device (3) is reduced. However, in the electric device disclosed in Patent Document 1, the planar speaker and the display device (3) are separately and independently provided in the housing (8). Therefore, it is difficult to manage the vertical distance between the diaphragm (2) and the display device (3) in the assembly process of the electric equipment, and the diaphragm (2) and the display device (3) come into contact with each other. There was a problem that a defect occurred.
An object of the present invention is to make the casing (8) thinner in an electrical apparatus including a flat speaker and a display device.

  In the frame (1), there is a transparent diaphragm (2) for outputting sound, a vibration supply part (4) for vibrating the diaphragm (2), and information located inside the diaphragm (2). And the diaphragm (2) and the display device (3) overlap each other with a gap, and the image of the display device (3) is viewed through the diaphragm (2), and the diaphragm (2 ) Has a peripheral portion mounted on and fixed to the frame (1).

  Since the periphery of the diaphragm (2) is placed on the frame (1), the height position of the diaphragm (2) is less varied. Since the diaphragm (2) and the display device (3) overlap each other and are fixed to the frame (1), the distance between the diaphragm (2) and the display device (3) should be positioned with high accuracy. And the problem that the diaphragm (2) and the display device (3) come into contact with each other can be prevented. Therefore, the distance between the diaphragm (2) and the display device (3) can be reduced as much as possible, and the casing (8) of the electric device can be thinned.

(overall structure)
Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
1 and 2 are perspective views of an electric device using the flat speaker unit (7) according to this example. FIG. 1 shows a mobile phone and FIG. 2 shows a PDA (personal digital assistant, mobile terminal device). Each one is shown. In the mobile phone of FIG. 1, the flat speaker unit (7) is housed in the housing (8). The casing (8) is connected to an auxiliary cabinet (5) having a plurality of operation buttons (50) and (50) by a hinge (51), and audio flows from the flat speaker unit (7). In the PDA of FIG. 2, operation buttons (50) and (50) are provided in a housing (8) that houses a flat speaker unit (7), and the sound from the accessed website is received by the flat speaker unit ( It starts from 7).

(Configuration of flat speaker unit)
FIG. 3 is a front view of the flat speaker unit (7), and FIG. 4 is a cross-sectional view of FIG. 3 taken along the plane including the line EE. The flat speaker unit (7) is configured by stacking a display device (3) that captures an image and a diaphragm (2) that outputs sound in a frame (1) with a gap. The frame (1) is formed from an insulating synthetic resin in view of the demand for weight reduction.
The frame (1) is provided with a rectangular first concave surface (10), and the display device (3) and the diaphragm (2) are provided in the first concave surface (10). The diaphragm (2) is formed from a transparent optical film.
The upper surface of the frame (1) and the central portion of the diaphragm (2) are located in substantially the same plane, the outer periphery of the diaphragm (2) is curved, and the outer periphery is the periphery of the first concave surface (10). To touch. The outer peripheral part of the diaphragm (2) is placed on the peripheral part of the first concave surface (10) and attached with an adhesive or the like. As will be described later, the diaphragm (2) is formed so that the outer peripheral portion is thinner than the central portion.
In the frame (1), a second concave surface (11) is provided on the inner side of the first concave surface (10) so as to be lowered by one step, and in the mounting hole (14) opened in the second concave surface (11). A display device (3) which is a liquid crystal panel is fitted.

On the second concave surface (11), outside the display device (3), there is a sound emitting hole (12) (12) whose bottom surface is opened (13) along the long side direction of the second concave surface (11). When the diaphragm (2) vibrates, the air in the frame (1) enters and exits through the sound emission holes (12) and (12).
On the second concave surface (11), outside the display device (3), a coil (40) (40) wound in a rectangle is provided along the short side direction of the second concave surface (11). The coils (40) and (40) are arranged with the display device (3) interposed therebetween. That is, the coils (40) and (40) are provided corresponding to both ends of the diaphragm (2), and thereby the diaphragm (2) vibrates at the same amplitude at both ends.
Each coil (40) is fitted into a positioning protrusion (20) protruding downward from the diaphragm (2). When the coil (40) is fitted into the positioning protrusion (20), the mounting position of the coil (40) does not vary. Since the coil (40) is covered with the transparent diaphragm (2), the coil (40) can be seen from above the diaphragm (2). May be shielded.

  The display device (3) is a liquid crystal panel as described above. As shown in the cross-sectional view of FIG. 5, the liquid crystal (31) is sealed between the glass substrates (30) and (30), and the substrate (30 ) Is attached to the outer surface of the polarizing plate (32). The lower substrate (30) faces the backlight (33), and when the substrate (30) is energized, the orientation of the liquid crystal (31) changes and the light of the backlight (33) is transmitted. As is well known, an image is displayed by switching between energization and interruption of the substrate (30).

6 is a cross-sectional view of FIG. 3 cut along a plane including the line DD, and FIG. 7 is an enlarged view of a portion F in FIG. A magnet member (41) is provided on the edge of the second concave surface (11), the positioning convex portion (20) faces the magnet member (41), and the coil (40) and the magnet member (41) The vibration supply part (4) which vibrates a diaphragm (2) by this is comprised.
As shown in FIG. 7, the magnet member (41) is configured by covering the circumferential surface and bottom surface of the magnet (42) with a yoke (43), and the magnet member (41) is formed on the second concave surface (11). It fits in the positioning recess (15) provided. Thereby, it is prevented that the attachment position of a magnet member (41) varies.
The diaphragm (2) is formed such that the outer peripheral thickness t2 is thinner than the central thickness t1. Since the coil (40) is provided on the outer periphery of the diaphragm (2), the outer periphery of the diaphragm (2) is likely to vibrate. In this case, it is conceivable to make the entire diaphragm (2) thin. However, in this case, the diaphragm (2) is liable to vibrate on the contrary, and an unnecessary sound may be generated. Further, if the entire diaphragm (2) is thin, the diaphragm (2) is likely to be deformed when the user carelessly presses the diaphragm (2) by hand. Therefore, the thickness t2 of the outer peripheral portion is formed thinner than the thickness t1 of the central portion to prevent generation of unnecessary sound and deformation of the diaphragm (2). Specifically, the thickness t2 of the outer peripheral portion of the diaphragm (2) is 20-75 μm, and the thickness t1 of the central portion is 100-150 μm.

(Vibration supply unit)
As shown in an enlarged view in FIG. 8, the magnetic flux output directly from the magnet member (41) passes only the positioning convex part (20) of the diaphragm (2) and does not vibrate the diaphragm (2).
However, the magnetic flux output obliquely upward from the magnet member (41) to the side passes through the coil (40). That is, the magnetic flux is absorbed by the yoke (43) and easily passes through the coil (40) located in the vicinity of the yoke (43). When an alternating current is applied to the coil (40) (current flows from the back side to the front side on the right side of the coil (40) in FIG. 8), the coil (40) vibrates upward in accordance with Fleming's law. The diaphragm (2) to which the coil (40) is attached vibrates and outputs sound. As described above, the image of the display device (3) can be seen through the diaphragm (2). Since the display device (3) and the diaphragm (2) for generating sound face each other and are close to each other, it is possible to view natural and realistic images and sounds.

(Effect of this example)
The planar speaker unit in this example has the following effects.
1. Since the periphery of the diaphragm (2) is placed on the frame (1), the height position of the diaphragm (2) is less varied. Since the diaphragm (2) and the display device (3) are overlapped with each other and are fixed to the frame (1), the vertical distance between the diaphragm (2) and the display device (3) is positioned with high accuracy. And the problem that the diaphragm (2) and the display device (3) are in contact with each other can be prevented. Therefore, the distance between the diaphragm (2) and the display device (3) can be reduced as much as possible, and the casing (8) of the electric device can be thinned.
In particular, it is not necessary to manage the vertical distance between the diaphragm (2) and the display device (3) in the manufacturing process of the manufacturer of the electric device incorporating the flat speaker unit, and the workability is good.
2. Since the diaphragm (2) constituting the speaker is rectangular, the space on the frame (1) can be used without waste. That is, the speaker is generally circular, but if the diaphragm (2) is formed in a circle and overlapped with the display device (3), there is no diaphragm and there is no useless sound that does not output sound as shown by the hatched lines in FIG. Part (2a) is produced. In this example, since the diaphragm (2) has a rectangular shape, such a useless portion (2a) does not occur, and the diaphragm (2) can be formed large, so that low sound can be easily produced and sound quality can be improved.

In the above example, the sound emitting hole (12) has an opening (13) on the lower surface, but the opening (13) may be covered with a mesh sheet (not shown) to have a water repellent effect. .
Further, two coils (40) are provided on the second concave surface (11), but four coils (40) may be provided to face each edge of the display device (3) as shown in FIG.
Further, the diaphragm (2) is formed such that the outer peripheral thickness t2 is thinner than the central thickness t1, but the diaphragm (2) is formed to have a uniform thickness t2 and a reinforcing plate (not shown) is formed in the central portion. A center portion of the diaphragm (2) may be reinforced.

In the above example, the coil (40) is provided in the diaphragm (2), and the magnet member (41) is provided in the second concave surface (11). A coil (40) may be provided in the concave surface (11).
The diaphragm (2) is attached to the peripheral edge of the first concave surface (10) with an adhesive or the like, but the diaphragm (2) is attached to the first concave surface (10) by a pressing member (not shown). It may be attached by pressing against the peripheral edge.
Furthermore, although the liquid crystal panel is illustrated as the display device (3), an organic EL (electroluminescence display) display or an inorganic EL display may be used instead. Here, the EL display has a well-known configuration in which a light emitter is deposited on a glass substrate. The organic EL display uses an organic material such as diamine as the light emitter, and the inorganic EL display uses an inorganic material such as zinc sulfide as the light emitter. When an EL display is used as the display device (3), the backlight (33) becomes unnecessary.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. In addition, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.
In the above example, the planar speaker unit is used for a mobile phone and a PDA, but may be used for a digital camera or a digital video.

It is a perspective view of a mobile phone. It is a perspective view of PDA. It is a front view of a planar type speaker unit. It is sectional drawing which fractured | ruptured FIG. 3 in the surface containing an EE line. It is sectional drawing of a liquid crystal panel. It is sectional drawing which fractured | ruptured FIG. 3 in the surface containing a DD line. It is an enlarged view of F part of FIG. It is an enlarged view of a magnet member. It is a front view of another planar speaker unit. It is a perspective view of the conventional planar speaker unit. It is sectional drawing which fractured | ruptured the planar speaker unit of FIG. 10 in the surface containing a BB line. It is an enlarged view of the C section of FIG. It is a front view of an undesired flat type speaker unit.

Explanation of symbols

(1) Frame
(2) Diaphragm
(3) Display device
(4) Vibration supply unit
(20) Positioning projection
(40) Coil
(42) Magnet

Claims (6)

In the frame (1), there is a transparent diaphragm (2) for outputting sound, a vibration supply part (4) for vibrating the diaphragm (2), and information located inside the diaphragm (2). And the diaphragm (2) and the display device (3) overlap each other with a gap, and the image of the display device (3) is visually viewed through the diaphragm (2).
A flat speaker unit, wherein the diaphragm (2) has a peripheral portion mounted on and fixed to the frame (1). The vibration supply unit (4) includes a coil (40) and a magnet (42), and either the coil (40) or the magnet (42) is attached to the diaphragm (2) and the other is attached to the frame (1). The planar speaker unit according to claim 1, wherein a plurality of the vibration supply units (4) are arranged to face the periphery of the rectangular display device (3). The flat speaker unit according to claim 1 or 2, wherein a peripheral portion of the diaphragm (2) is formed thinner than a central portion. A positioning projection (20) is formed on the peripheral edge of the diaphragm (2), and the coil (40) is fitted to the positioning projection (20) on the lower surface of the diaphragm (2). 4. The planar speaker unit according to any one of 3 above. The flat speaker unit according to any one of claims 1 to 4, wherein the display device (3) is any one of a liquid crystal panel, an organic EL display, and an inorganic EL display. An electrical apparatus comprising the planar speaker unit according to any one of claims 1 to 5.

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