JP4197992B2 - Flat speaker and electronic device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat speaker and an electronic apparatus in which the flat speaker is disposed on the front surface of a display such as a mobile phone or a notebook computer.
[0002]
[Prior art]
As a flat speaker used for a cellular phone, a notebook personal computer or the like, those shown in FIGS. 9 and 10 are known.
[0003]
This flat speaker is composed of a main part (10) that is exposed to the outside through an opening (41) of a main body of an electronic device (40) such as a mobile phone and a laptop computer, and a stepped portion at the periphery of the main part (10) A diaphragm (1) comprising an edge portion (11) protruding through (11a) and a case (53) provided in the edge portion (11) of the diaphragm (1) housed in a case (53) A yoke (22) fixed by appropriate means inside, a magnet (21) provided in the yoke (22), a top plate (51) solidified on the top surface of the magnet (21), and a magnetic gap And a magnetic circuit (2) composed of a drive coil (20) to be driven, and is configured by fixing one end of the drive coil (20) to the diaphragm (1) (for example, practical use). New literature 1).
[0004]
In such a flat speaker arranged in front of the display (50) such as the electronic device (40), the magnetic circuit (2) is arranged so that visual information from the display (50) is not obstructed. Arranged at the edge.
[0005]
[Utility model document 1]
Utility Model Registration No. 3078022 (first page, FIGS. 1 to 3)
[0006]
[Problems to be solved by the invention]
Currently, electronic devices such as mobile phones and notebook computers are required to have smaller main bodies and larger displays. If the area of the display is increased, it is necessary to increase the area of the main part of the diaphragm of the flat speaker placed in front of the display. However, the diaphragm cannot be enlarged in a limited space of the electronic device body. When the main part becomes wide, the edge part becomes narrow. For this reason, a large magnetic circuit cannot be arranged at the edge, and there is a problem that the sound pressure decreases.
[0007]
Further, the speaker described in the utility model document 1 has a drive coil (20) disposed in the magnetic gap between the yoke (22) and the magnet (21) provided in the yoke (22). Space is required, a large magnet (21) cannot be used, and the work for providing the magnetic gap in the production process is complicated.In the magnetic gap, the yoke (22) and the drive coil (20), Or there exists a problem that a defect generate | occur | produces when a drive coil (20) and a magnet (21) contact.
[0008]
Accordingly, in view of the above problems, the present invention provides a flat speaker that is improved in sound pressure without increasing the size of the magnetic circuit (2) and that is excellent in productivity, and an electronic device using the same.
[0009]
[Means for Solving the Problems]
The present invention comprises a diaphragm (1) comprising a main part (10) having a transparent and flat shape and an edge part (11) located at the periphery of the main part (10), and fixed to the diaphragm (1). Drive coil (20), a magnetic circuit comprising the drive coil (20), a magnet (21) disposed at a fixed position with a predetermined gap, and a yoke (22) to which the magnet (21) is attached (2)
A plurality of the magnetic circuits (2) are arranged at the edge of the diaphragm (1), the drive coil (20) has a winding axis perpendicular to the diaphragm (1), and the number of turns is the vibration. What is wound more in the horizontal direction than in the vertical direction with respect to the plate is used, and the drive coil (20) and the diaphragm (1) are in surface contact, and the drive coil (20) is the magnet. (21) It is mainly driven by a magnetic flux component in a direction parallel to the diaphragm (1).
[0010]
The magnet (21) is covered with a yoke (22) except for the surface on the drive coil (20) side, and the magnetic flux component emitted from the surface on the drive coil (20) side of the magnet (21) It is preferable to operate the drive coil (20).
[0011]
By using the above configuration, the contact area between the diaphragm (1) and the drive coil (20) is increased as compared with the conventional product, and the vibration of the drive coil (20) is more easily transmitted to the diaphragm (1). The sound pressure can be improved without increasing the size of the circuit (2). In addition, since there is no need to provide a magnetic gap, there is a problem that a defect occurs due to contact between the yoke (22) and the drive coil (20) or the drive coil (20) and the magnet (21) in the gap in the production process. As a result, the productivity can be improved and the top plate (51) is not necessary, and the cost can be reduced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The flat speaker according to the present invention is used by being arranged on the front surface of the one that conveys visual information, and is incorporated in an electronic device (40) such as a mobile phone or a laptop computer, for example, of the display (50) of the electronic device (40). Located on the front.
[0013]
The flat speaker in the present invention includes a magnetic circuit (2) and a diaphragm (1), and the magnetic circuit (2) includes a plurality of driving coils (fixed to the edge (11) of the diaphragm (1). 20), each drive coil (20), a magnet (21) disposed at a fixed position with a predetermined gap, and a yoke (22) to which the magnet (21) is attached.
[0014]
The drive coil (20) has a winding axis perpendicular to the diaphragm (1) and is wound in a spiral shape, and the number of turns of the drive coil (20) is perpendicular to the diaphragm (1). The drive coil (20) is in surface contact with the diaphragm (1) as a bundle of coil wires on the diaphragm (1).
[0015]
The drive coil (20) used in the present invention is formed in a circular shape, an elliptical shape or a square shape as shown in FIG.
[0016]
The magnetic circuit (2) of the present invention comprises a drive coil (20) in which a component of the magnetic flux emitted from the drive coil (20) side of the magnet (21) mainly flows in a direction parallel to the diaphragm (1). ), An electromagnetic force in accordance with Fleming's left-hand rule is generated. As a result, the diaphragm vibrates integrally with the drive coil in surface contact with the diaphragm (1), thereby generating a sound. Further, the magnetic flux adsorption and power generation action generated by applying an AC component to the drive coil, which is described in Japanese Patent No. 3321521, previously devised by the present applicant, is used as an additional drive.
[0017]
Further, by covering the magnet (21) other than the surface on the drive coil (20) side with the yoke (22), the magnetic flux component emitted from the surface on the drive coil (20) side of the magnet (21) can be used efficiently. The sound pressure can be improved.
[0018]
A plurality of the magnetic circuits (2) are arranged on the edge (11) of the diaphragm (1) so as not to obstruct visual information. Further, since all the magnetic circuits (2) are electrically connected in parallel, the electromagnetic force can be generated in the same phase, so that the vibration applied to the diaphragm (1) is increased and the sound pressure can be improved. it can.
[0019]
The diaphragm (1) according to the present invention has a transparent and flat main part (10) and a peripheral part of the main part (10) so that visual information such as the display (50) of the electronic device (40) can be seen. It comprises an edge (11) to which the provided magnetic circuit (2) is attached. The main portion (10) is preferably formed thicker than the edge portion (11) because the strength decreases and the sound quality deteriorates as the area increases, and the diaphragm (1) is preferably formed when the diaphragm (1) is formed. Using a thick main part (10) and the same thickness of the main part (10) and the edge part (11), a transparent and flat reinforcing plate is bonded to the main part (10) with double-sided tape. Attached with an agent or the like is used. The ratio of the thickness of the main part (10) to the edge part (11) is preferably 1.5: 1 to 3: 1. If the main portion (10) is thinner than this range, the effect of improving the strength is not obtained so much and the sound quality is lowered. Also, if the main part (10) is thicker than this range, the vibration part will increase in weight and cause a decrease in sound pressure.
[0020]
The diaphragm (1) is made of a highly transparent material such as polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate (PEN), polyetherimide (PEI), polyimide (PI), etc. Formed from.
[0021]
Further, in the diaphragm (1), as the flat area is wider, the strength of the main part (10) becomes weaker. Therefore, the diaphragm (1) is formed to have a convex cross section and is formed on the edge (11). By providing the step portion (11a) for providing the step, the flat area of the diaphragm (1) can be reduced, and the strength of the main portion (10) can be improved. Furthermore, the space can be used effectively by disposing the display (50) such as a liquid crystal screen in the space formed by forming the diaphragm (1) to have a convex cross section.
[0022]
Furthermore, a diaphragm convex part (11b) for positioning the drive coil (20) is arranged on the edge part (11) of the diaphragm (1), and a frame for positioning the yoke (22) on the frame (3). Providing the body recess (3a) improves productivity and prevents displacement during mounting.
[0023]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0024]
(Example)
FIG. 1 shows a top view (a) and a cross-sectional view (B) of AA of the flat speaker in the embodiment. This flat speaker has a convex section and a diaphragm (1) consisting of a main part (10) and an edge part (11), and a magnetic circuit (2) arranged on the edge part (11) of the diaphragm (1). A frame (3) to which the edge (11) of the diaphragm (1) and the yoke (22) of the magnetic circuit (2) are attached, and a frame circuit board (not shown) electrically connected to an external circuit. Z).
[0025]
FIG. 2 shows a cross-sectional view of the magnetic circuit (2) used for the speaker of the first embodiment. The magnetic circuit (2) includes a drive coil (20) wound in a spiral shape having a winding axis perpendicular to the diaphragm (1) and formed into an elliptical shape, and a predetermined gap in the drive coil (20). A rectangular magnet (21) disposed at a fixed position and a yoke (22) that covers the magnet (21) except for the surface on the drive coil (20) side, the yoke (22) being a frame The drive coil (20) is disposed on the lower surface of the diaphragm convex portion (11b) provided on the edge (11) of the diaphragm (1), and is disposed in the frame concave portion (3a) provided on the body (3). Inserted and fixed with an adhesive or the like. The magnetic circuit (2) is disposed on the upper and lower sides and the left and right sides of the edge (11) of the diaphragm (1), and the magnetic circuit (2) of the frame (3) is not disposed. The part is provided with a sound emitting hole (3b).
[0026]
FIG. 3 shows a cross-sectional view of the diaphragm (1) used in the speaker of the first embodiment. The diaphragm (1) is made of PET as a material, and a transparent and flat main part (10) and a peripheral edge of the main part (10) so that a display (50) such as an electronic device (40) can be seen. And an edge portion (11) to which a drive coil (20) provided on the head is attached. The thickness (t1) of the main part (10) is 100 to 150 μm, the thickness (t2) of the edge (11) is 50 to 75 μm, and the edge (11) is the frame body. It is fixed to (3) with an adhesive. The drive coil (20) is in surface contact with the diaphragm (1) as a bundle of coil wires and is fixed to the diaphragm (1) with an adhesive.
[0027]
A frame circuit board is attached to the back surface of the frame body (3), and lead wires led out from the drive coil (20) are electrically connected to the frame circuit board.
[0028]
FIG. 6 is a cross-sectional view of the flat speaker of the present invention attached to the electronic device (40). By forming the diaphragm (1) to have a convex cross section, the strength of the diaphragm (1) is improved compared to the flat shape of the entire surface and the convex shape of the cross section can be achieved. The display (50) can be arranged in the space, and the electronic device can be miniaturized by effectively using the space.
[0029]
As shown in FIG. 11, a conventional flat speaker as described in Utility Model Reference 1 uses a cylindrical coil wound as a drive coil (20). There is no contact. On the other hand, the drive coil (20) used in the flat speaker of the present invention is wound in a spiral shape, and uses a winding having a larger number in the horizontal direction than in the vertical direction with respect to the diaphragm. The plate (1) is in surface contact with a bundle of coils. Therefore, the vibration of the drive coil (20) is easily transmitted to the diaphragm (1), and the sound pressure can be improved without increasing the size of the magnetic circuit (2).
[0030]
As shown in FIG. 5, the vibration plate (1) is vibrated by a component in a direction parallel to the vibration plate (1) of the magnetic flux emitted from the drive coil (20) side of the magnet (21). 51) is no longer necessary and costs can be reduced.
[0031]
In addition, since there is no need to provide a magnetic gap, defects occur when the yoke (22) and the drive coil (20) or the drive coil (20) and the magnet (21) are in contact with each other in the magnetic gap in the production process. This eliminates the problem of improving the productivity. Further, a yoke (22) is arranged in a frame body recess (3a) provided in the frame body (3), and a drive coil (11b) is mounted on a diaphragm projection (11b) of an edge (11) of the diaphragm (1). By arranging 20), the magnetic circuit (2) can be easily positioned, leading to further improvement in productivity.
[0032]
In the embodiment, the electronic device (40) is placed in front of the nameplate of the painting at a museum or the like, and used for announcements, or placed in front of the animal nameplate in the zoo. Needless to say, it can be used for announcements, etc., and can be applied to other applications.
[0033]
Further, as shown in FIGS. 7 and 8, a predetermined gap is provided on the magnet (21), and a second magnet (21a) opposite to the magnet (21) is disposed, and two magnets are used. By sandwiching the drive coil (20), the magnetic flux component in the direction parallel to the diaphragm (1) can be increased, and the sound pressure can be further improved.
[0034]
【The invention's effect】
The present invention provides a diaphragm (1) comprising a main part (10) having a transparent and flat shape and an edge part (11) located at the periphery of the main part (10), and an edge of the diaphragm (1). A plurality of drive coils (20) fixed to the section (11), a magnet (21) arranged at a fixed position with a predetermined gap from each drive coil (20), and the magnet (21) is attached A planar speaker comprising a yoke (22)
While increasing the sound pressure without increasing the size of the magnetic circuit (2), it is possible to provide a flat speaker with excellent productivity and an electronic device (40) using the same.
[Brief description of the drawings]
FIG. 1A is a top view of a flat speaker according to a first embodiment of the present invention, and FIG.
FIG. 2 is a cross-sectional view of a porcelain circuit used in the flat speaker according to the first embodiment.
3 is a cross-sectional view of a diaphragm used in the flat speaker according to Embodiment 1. FIG.
4A and 4B are a plan view and a cross-sectional view of a drive coil used in the present invention.
FIG. 5 is a distribution diagram of magnetic flux components of a magnet according to the present invention.
FIG. 6 is a cross-sectional view of an electronic apparatus to which the planar speaker of the present invention is attached.
FIG. 7 is a cross-sectional view of a flat speaker according to another embodiment.
FIG. 8 is a cross-sectional view of a magnetic circuit used in a flat speaker according to another embodiment.
FIG. 9 is a cross-sectional view of an electronic apparatus equipped with a conventional flat speaker.
FIG. 10 is a cross-sectional view of a magnetic circuit used in a conventional flat speaker.
FIG. 11 is a plan view and a cross-sectional view of a drive coil in a conventional flat speaker.
[Explanation of symbols]
(1) Diaphragm
(10) Main part
(11) Edge
(11a) Step
(11b) Diaphragm convex part
(2) Magnetic circuit
(20) Drive coil
(21) Magnet
(21a) Second magnet
(22) York
(3) Frame
(3a) Recessed frame
(3b) Sound vent
(40) Electronic equipment
(41) Opening
(50) Display
(51) Top plate
(53) Case

Claims (11)

A diaphragm (1) comprising a main part (10) having a transparent and flat shape and an edge part (11) located at the periphery of the main part (10), and a drive coil fixed to the diaphragm (1) (20), the drive coil (20), a magnetic circuit (2) comprising a magnet (21) disposed at a fixed position with a predetermined gap, and a yoke (22) to which the magnet (21) is attached. In a flat speaker comprising
A plurality of the magnetic circuits (2) are arranged on the edge (11) of the diaphragm (1), the drive coil (20) has a winding axis perpendicular to the diaphragm (1), and the number of turns Is wound more in the horizontal direction than in the vertical direction with respect to the diaphragm, and the drive coil (20) and the diaphragm (1) are in surface contact, and the drive coil (20) Drives the diaphragm (1) mainly by a magnetic flux component parallel to the diaphragm (1) of the magnet (21), and the magnet (21) has a yoke other than the surface on the drive coil (20) side. A flat speaker , which is covered with (22) and operates the drive coil (20) by a magnetic flux component emitted from the surface of the magnet (21) on the drive coil (20) side .   The flat speaker according to claim 1, wherein the drive coil (20) is wound in a circular shape, an elliptical shape or a rectangular shape. The flat speaker according to claim 1 or 2 , wherein all of the plurality of magnetic circuits (2) are connected in parallel.   The flat speaker according to any one of claims 1 to 3, wherein the main part (10) of the diaphragm (1) is formed thicker than the edge part (11).   The flat speaker according to any one of claims 1 to 4, wherein the main part (10) is formed thicker than the edge part (11) by attaching a transparent and flat reinforcing plate. 6. The flat speaker according to claim 4 , wherein a ratio of a thickness of the main part (10) to the edge part (11) is 1.5: 1 to 3: 1. The said diaphragm (1) is formed in the cross-sectional convex shape, The said edge (11) has the step part (11a) which provides a level | step difference, The Claim 1 thru | or 6 characterized by the above-mentioned. Flat speaker.   The planar surface according to claim 1, wherein a diaphragm convex portion (11 b) for positioning the drive coil (20) is provided at an edge (11) of the diaphragm (1). Speaker.   The planar speaker includes a frame (3) to which an edge (11) of the diaphragm (1) and a yoke (22) of a magnetic circuit (2) are attached, and the yoke (22) is attached to the frame (3). The flat speaker according to any one of claims 1 to 8, further comprising a frame recess (3a) for positioning the speaker.   A predetermined gap is provided on the magnet (21), a second magnet (21a) opposite to the magnet (21) is disposed, and the drive coil (20) is sandwiched between the two magnets. The flat speaker according to claim 1 to 9.   An apparatus main body and a display (50) arranged at a predetermined position of the apparatus main body for visually displaying information, the flat speaker according to claim 1 to 10 is provided on a front surface of the display (50). Electronic device (40) characterized by being arranged.

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