Loudspeaker with non-uniform suspension and stiffening element

Abstract

A loudspeaker has an uneven fold, a diaphragm, and a reinforcing element that prevents the fold from bending the diaphragm during operation. The uneven fold does not have a uniform cross-section along the radius of the loudspeaker (if it is circular) around the entire perimeter of the diaphragm, because some portions will point upwards while others will point downwards.

Description

Technical Field

[0001] The present invention relates to a loudspeaker with a non-uniform suspension, such as a suspension that does not have the same cross-section throughout its entire range, and the loudspeaker having reinforcing or strengthening elements. Background Technology

[0002] Amplifiers with uniform or non-uniform suspension can be found in US6305491, US2011 / 164782, EP0556786, US2002 / 170773, Fostex UDR Amplifier (https: / / www.fostexinternational.com / docs / speaker_components / pdf / fe208ez.pdf), US6889796, US2003 / 0231784, EP1659823, and the 1995 AES article "Nonlinearity of Diaphragm Area and Mass in Conical Amplifiers" by Knud Thorborg and Erling Sandermann Olsen. Other uniform suspension systems can be found in US7218748, EP1788839, US3997023, US3130811 and the KEF white paper http: / / www.kef.com / uploads / files / THE_REFERENCE / REF_White_Paper_preview_path_200514.pdf.

[0003] Non-uniform suspension can be provided for a variety of reasons, one of which is uniform suspension, such as half-roll, full-roll, and multiple-roll suspensions, which, together with the membrane, will produce an effective membrane area that depends on the membrane's position relative to the rack. Non-uniform suspension can be shaped to avoid this variation. However, it has been found that non-uniform suspension generates uneven forces acting on the membrane edges, causing membrane bending and thus producing undesirable vibrations and noise. Summary of the Invention

[0004] One object of the present invention is to provide a loudspeaker having an uneven surround but whose diaphragm does not bend due to the operation of the surround.

[0005] In a first aspect, the present invention relates to a loudspeaker comprising a diaphragm, a surround, and a frame, wherein:

[0006] -The membrane has an outer edge.

[0007] - The folding ring connects to the basin frame and at least substantially all the outer edges of the membrane.

[0008] - The fold has a first part and a second part, wherein:

[0009] - The first part points upwards, such as through a first radial cross section, and

[0010] - The second part points downwards, such as by having a second radial cross-section, wherein the first radial cross-section and the second radial cross-section have different shapes.

[0011] The loudspeaker also includes reinforcing elements located at the outer edge of the membrane.

[0012] In this article, a loudspeaker is a component constructed to generate and output sound. A typical loudspeaker consists of a diaphragm or vibrating diaphragm that can be moved by a motor relative to a frame, housing, part of the motor, etc.

[0013] A diaphragm is typically a relatively rigid and usually planar or funnel-shaped element, connected to an actuator for moving the diaphragm. The diaphragm usually forms a sound and / or at least substantially airtight seal between the amplifier's chamber and the surrounding area. Naturally, multiple diaphragms can be present in an amplifier and can be positioned within the same chamber. Sound output ports, such as bass reflex ports, may also be present if desired.

[0014] Membranes can be made of paper, cardboard, metal, polymers, or combinations thereof. Membranes can be symmetrical about an axis, such as axial symmetry. Typically, membranes are circular, but elliptical membranes and rectangular membranes with rounded corners can also be seen.

[0015] The membrane may have a central axis defined as the intersection between two planes of symmetry. Typically, the intended direction of membrane movement is along the central axis. The central axis has an upward direction away from the motor and towards the membrane.

[0016] The membrane and folds can have a radial cross-section defined as a cross-section passing through a plane coinciding with the central axis. The radial cross-section of the folds can have a maximum and a minimum value, the maximum value being the point furthest upward along the central axis and the minimum value being the point furthest downward along the central axis. An extreme value is one of the maximum and minimum values.

[0017] The membrane surface can be more or less flat or planar, or it can have more contours. The membrane can have ridges, such as in directions away from the central axis, to increase the membrane's stiffness, for example. Other types of membranes have ridges formed as concentric rings at least in the outer portions, which serve to cause only the innermost portion of the membrane to vibrate at a higher frequency, while more and more portions of the membrane vibrate at increasingly lower frequencies.

[0018] The basin frame is preferably a rigid or stiff element that will not deform to any significant extent due to the operation of the drive mechanism moving the diaphragm to produce sound. Typically, the basin frame is made of metal. Generally, the basin frame is conical, having a base portion to which the drive mechanism is attached, and an outer portion having a shape corresponding to a folding ring to which the folding ring is attached. A strut can be formed between the base portion and the outer portion to connect them, while allowing space for diaphragm movement.

[0019] Typically, the speaker basket will be connected to the amplifier enclosure at its external part to ensure that air cannot escape from the enclosure through the amplifier to at least no significant extent.

[0020] The membrane has an outer edge. The shape of this edge typically defines the shape of the membrane. Membranes are usually circular.

[0021] A folding ring is a flexible element that connects a typically rigid diaphragm to a typically more rigid frame to allow the diaphragm to move relative to the frame while controlling the movement of the diaphragm relative to the frame and / or ensuring that air cannot bypass the edges of the diaphragm. This would short-circuit the diaphragm, thereby compromising its sound-generating characteristics.

[0022] Existing folded loops are typically half-rolled or fully rolled, and have the same profile along the extent of the fold, i.e., these folded loops have a uniform profile. Typically, the conical edge and the folded loop are circular (projected onto a plane perpendicular to the central axis). In this case, the uniform profile folded loop will be axisymmetric, i.e., it can be described as a profile defined in a 2D plane rotating about the central axis.

[0023] Typically, loops are made of rubber, impregnated cloth, or closed foam because such materials are lightweight, flexible, and still airtight to any significant extent.

[0024] The connection between the fold and the membrane can be performed using, for example, glue (or by co-molding the fold onto the membrane). Naturally, any type of fastener can be used.

[0025] Typically, it is desirable for loops to be attached or connected to the membrane at all external portions and / or peripheries to maintain good control over the membrane at all outer edges, ensuring that air cannot pass through the membrane / loop assembly.

[0026] Many fold types cause the effective acoustic radiation area of ​​the membrane / fold assembly to vary as a function of the membrane's position relative to the frame. Typically, the effective area is higher when the membrane is as close to the frame as possible (the two extremes of the membrane's operating interval). This is because, for example, in a standard half-roll configuration, the fold shape differs in these two positions.

[0027] There exists a fold that reduces this problem. This type of fold has a first part and a second part, wherein:

[0028] -The first part has a first radial cross section, and

[0029] -The second part has a second radial cross section.

[0030] The first radial cross section and the second radial cross section have different shapes.

[0031] Therefore, this type of fold has different radial cross-sections at different locations along the fold, meaning the fold profile is not uniform along its circumference. When viewed from the membrane towards the frame, such as from a portion of the membrane's outer edge to the nearest point on the frame, the cross-section can be the cross-section of the fold. If the membrane is axisymmetric, then the frame is also axisymmetric, and therefore the inner and outer portions of the fold are also axisymmetric. In this case, the first portion is the radial portion.

[0032] When two sections have different radial cross-sections, this means that the shape of the fold around or along the fold is not the same. These two sections can have different curve shapes, different highest or lowest points, such as when measured from the outer edge of the membrane. The height can be seen relative to a straight line from the edge of the membrane and the nearest point of the frame—or from between the inner and outer edges of the fold.

[0033] For example, if one part is more than 10% taller at a selected distance from the membrane edge and / or the central axis of the membrane than another part is taller at the same distance, then these parts are different.

[0034] For several reasons, the folds may be non-uniform. One reason is that, as mentioned above, the membrane has at least the same effective area when moving relative to the frame. In this case, the effective area of ​​the membrane is usually the same because the membrane is generally rigid enough not to bend to any significant degree. For a half-roll, the relevant area of ​​the fold is approximately the area of ​​all parts of the fold within the apex of the radial cross-section of the fold. For a half-roll, the maximum value changes depending on the displacement of the membrane along the central axis, moving towards or away from the central axis, thus altering the effective area.

[0035] Other loops have an uneven profile to prevent sound waves from leaving the loop.

[0036] One object of the present invention is to reduce membrane bending caused by uneven folding. Therefore, the loudspeaker further includes reinforcing elements disposed at the outer edge of the membrane, such as at the interface between the membrane and the folding.

[0037] The reinforcing element functions to make the membrane and folded ring assembly more rigid. It has been found that non-uniform folded rings, which do not have a uniform radial cross-section along their entire length, cause the membrane to bend at the outer edges. This bending again leads to distortion of radiated sound, which is clearly undesirable.

[0038] Therefore, the function of the reinforcing element is to prevent the outer edge of the membrane from bending during membrane movement. Consequently, the reinforcing element should be adapted to the expected force of the pleats used. Depending on the shape of the pleats, the non-uniformity of the force acting on the outer edge of the membrane can be more or less significant.

[0039] When a membrane bends, portions of the outer edge are pulled inward toward the center, while other portions are pushed outward away from the central axis. Its outer edge deviates from its shape when at rest and not in motion. For example, if the membrane is circular, bending will change its shape, thus giving it multiple lobes. Two lobes will make the edges elliptical. Three lobes will give it a more triangular shape. This phenomenon can occur at certain resonant frequencies.

[0040] The reinforcing element can be as simple as a layer of selected material attached to the membrane and / or fold, such as a portion of a fold adjacent to or attached to the outer portion of the membrane. Clearly, the additional layer material can increase stiffness. However, further below, other shapes of folds are described to further increase stiffness, while maintaining attention to the mass added by the reinforcing element.

[0041] The stiffening element can have different stiffnesses in different directions, such as in the direction perpendicular to the range of the stiffening element and / or toward the central axis of the membrane, and in the direction of movement of the membrane and / or the actuator. However, due to the considerable complexity of membrane bending, it may be desirable for the stiffening element to have at least substantially the same stiffness in all directions, such as in all directions perpendicular to the centerline of the stiffening element or perpendicular to the outer edge of the membrane at a particular point.

[0042] The non-uniformity of the fold can be defined in many ways. In one case, the radial cross-sections of the first and second portions each define a curve, such as the upper surface, lower surface, or center of the fold. The curve defined by the radial cross-section of the first portion can then be shorter than the curve defined by the radial cross-section of the second portion. A shorter curve can be obtained when the curve between the two poles is straighter. This curve can be derived relative to the aforementioned straight line.

[0043] In one or the other case, the curve defined by the radial cross-section of the first part may have a narrower bend than the curve defined by the radial cross-section of the second part. The narrower bend may be a narrower crest or trough.

[0044] In one case, the radial cross-sections of the first and second portions have maximum (or minimum) values ​​at different distances from the center of the membrane. Similarly, this can be determined relative to the straight line described above.

[0045] In one case, the radial cross-section of the first part and / or the second part can be U-shaped or V-shaped. Then, the portion between the first part and the second part can have an M-shaped or W-shaped radial cross-section.

[0046] Furthermore, the fold preferably defines a repeating pattern along its central closed curve. The fold can then have multiple portions with the same radial cross-section as a first radial cross-section and multiple portions with the same radial cross-section as a second radial cross-section.

[0047] Clearly, the reinforcing element can have any desired radial cross-section, such as a planar element or a sheet of material. A preferred shape is one in which a portion of the reinforcing element has an L-shaped, T-shaped, or I-shaped radial cross-section. One of the planar sides of the reinforcing element can then be attached to a membrane and / or a fold.

[0048] In another embodiment, the reinforcing element has a portion having a radial cross-section with a polygonal shape, such as a triangle, rectangle (square, rhombus, parallelogram, trapezoid, kite-shaped, etc.). Similarly, one of the planar sides can then be attached to the membrane and / or the loop.

[0049] In practice, one of the basic planar sides of an L-shape, I-shape, T-shape, or polygon can be formed by a membrane and / or loop, such that the desired shape is not achieved before being attached to the membrane / loop.

[0050] Alternatively, the reinforcing element may have a portion with an elliptical radial cross-section, such as a circle.

[0051] Clearly, the shape, size, material, etc., can be selected based on the bending force applied to the membrane and the maximum weight increase caused by the reinforcing elements.

[0052] Preferably, the reinforcing element forms a closed curve in a predetermined plane, such as the plane containing the outer edge of the membrane. The advantage of a closed curve is that the reinforcing element is present around the entire membrane. Preferably, the curve is at least 75% of the radius / distance from the center. Obviously, the reinforcing element does not need to be positioned at the outer edge of the membrane to reinforce the outer portion of the membrane, as the membrane typically has its own stiffness. However, it is desirable for the reinforcing element to be positioned at least in the outer quarter of the membrane to perform its function—that is, at a distance from the center of the membrane not less than 75% of the distance from the center to the outer edge of the membrane. If the membrane is not circular, the reinforcing element typically has the same shape and is therefore positioned at the same percentage of the total distance, whether measured perpendicularly from the central axis or along the membrane surface from the central axis.

[0053] In one scenario, when projected onto a plane, the mass per unit area of ​​the combined membrane and stiffening element is higher at the stiffening element than inside the closed curve. While having a higher mass at the stiffening element may not be the objective in itself, the increased mass generally implies or results in higher stiffness.

[0054] In one embodiment, the diaphragm and the stiffening element have a first unit area mass in a plane perpendicular to the direction of movement of the diaphragm, and the diaphragm has a second unit area mass in a plane not at the location of the stiffening element, wherein the first unit area mass is greater than the second unit area mass. Although a higher unit area mass is not an objective in itself in this projection, a higher mass generally provides the desired higher stiffness.

[0055] In one embodiment, the combined membrane and reinforcing element have a thickness in a direction perpendicular to the plane, said thickness being greater at the reinforcing element than inside the closed curve. While a greater thickness is not an objective in itself, a greater thickness typically provides the desired higher stiffness.

[0056] As described above, the reinforcing element can be a separate element attached to the membrane, or the membrane can be manufactured with a built-in reinforcing element, preferably located at its outer portion. This built-in reinforcement can be achieved by adding an element to the membrane material during the membrane manufacturing process, by providing a thicker, heavier, more rigid membrane material at its outer portion. In one case, the membrane can be molded, wherein the mold can be designed to produce the reinforcing element as described above. If desired, the molding process can be two-component molding. Alternatively, a portion of the membrane can be formed or shaped to constitute a thicker, more rigid portion.

[0057] A second aspect of the present invention relates to a method of assembling a loudspeaker, the method comprising:

[0058] - Provides a membrane with an outer edge.

[0059] - Provide a folded ring having a first part and a second part, wherein:

[0060] - The first part points upwards, such as through a first radial cross section, and

[0061] - The second part points downwards, such as by having a second cross-section, wherein the shapes of the first and second cross-sections are different.

[0062] -Provide reinforcement components, and

[0063] - Secure the outer edge of the membrane to the fold and reinforcement elements.

[0064] Naturally, this aspect can be combined with the first aspect. The membrane, the folded ring, the first part and the second part, and the reinforcing element can be as described above. Attached Figure Description

[0065] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0066] - Figure 1 A radial cross-section of a loudspeaker according to the invention is shown.

[0067] - Figure 2 A first embodiment of the reinforcing element and its projected thickness are shown.

[0068] - Figure 3 A second embodiment of the reinforcement element is shown.

[0069] - Figure 4 A third embodiment of the reinforcement element is shown.

[0070] - Figure 5 A first embodiment of the non-uniform folded ring is shown.

[0071] - Figure 6 A second embodiment of the non-uniform folded ring is shown.

[0072] - Figure 7 Alternative films with thicker or different materials at the outer edges are shown.

[0073] - Figure 8-13 Different types of reinforcement elements are shown. Detailed Implementation

[0074] exist Figure 1 In the diagram, the loudspeaker 1 is shown having a diaphragm 2, a motor 4, a frame 6, and a pleated ring 8. The motor is configured to move the diaphragm up and down along axis A, and the pleated ring is configured to prevent air from bypassing the outer edge 12 of the diaphragm 2 and to control the movement of the diaphragm 2. The pleated ring 8 is connected to the frame 6 at its outer periphery.

[0075] When the surround is not perfectly uniform, the movement of the diaphragm will cause the surround to bend, which in turn will cause the diaphragm to bend again during movement. This bending results in distortion of the sound output, which is naturally undesirable. Figure 1 In the middle, the folded ring 8 is shown to be non-uniform, which can be seen from the different shapes of the cross-sections on the left and right sides.

[0076] exist Figure 5 and Figure 6 Uneven folds can be seen in the image. Figure 5The folded ring, as seen in US6516077, has multiple ridges 18 tangent to the outer edge 12. The remainder of the folded ring has the shape shown at reference numeral 16. Clearly, different portions of the folded ring have different radial cross-sections and therefore have different effects on the outer edge 12.

[0077] Figure 6 The fold ring in the image can be seen in EP0556786, where... Figure 1 In the cross-section shown, part of the fold points downwards and part points upwards, with the intersection of these parts appearing as... Figure 6 The intersection point in the diagram. Clearly, looking from the leftmost and rightmost sides of the same diagram, Figure 6 The portion shown has a different effect on the membrane than the half-roll portion.

[0078] When in motion, these different effects on different parts of the outer edge will cause the membrane to bend.

[0079] To resist this bending, a reinforcing element 10 is provided at the interface between the membrane and the loop. Figure 2-4 Different shapes of this reinforcing element are shown.

[0080] Bending of a membrane is a deformation that causes the outer edge to be pulled towards the central axis of the membrane while the rest is pushed away from the central axis. Different bending modes exist, with the first mode where the outer edge becomes elliptical, the second mode where the outer edge has three lobes, and the third mode where it has four lobes. Clearly, any number of lobes can be observed when the membrane is bent.

[0081] Figure 2 The radial cross-section of the outer edge 12 of the membrane 2 and the reinforcing element 10 is shown, wherein the radial cross-section of the reinforcing element is rectangular. One side of the rectangle may be made of the membrane material. The reinforcing element extends along the outer edge of the membrane and is generally a closed curve when projected onto a plane perpendicular to axis A. Clearly, the reinforcing element will resist bending of the outer edge 12. The projected thickness of the assembly of the membrane and reinforcing element on a plane perpendicular to the central axis A is also shown.

[0082] The radial cross-section of the reinforcing element can have any desired shape. Figure 3 In the case of a membrane, the shape is triangular. Similarly, the membrane material can form one of the sides. Advantageously, the shape can be a closed curve, such as a rectangle, polygon, or ellipse.

[0083] exist Figure 4 In this case, the radial cross-section of the reinforcing element has a circular shape.

[0084] Naturally, reinforcing elements of any shape can be used. Polygons can be used, and one or more sides can be formed by a membrane if desired.

[0085] The reinforcing element can be hollow or filled with a filler material, such as foam.

[0086] The reinforcing element can be made of any type of material. Obviously, high stiffness is desired, but the weight is desired to be as low as possible. Thin aluminum, such as 0.5 mm or less, such as 0.25 mm or less, such as 0.2 mm or less, such as 0.15 mm or less, can be used, as well as other materials such as metals, alloys, polymers, paper, cardboard, plastics, composite materials, Kevlar, etc.

[0087] Individual reinforcement elements can be replaced by adaptations to the membrane material. Typically, the membrane is made of the same material with the same thickness across its entire surface and perpendicular to its length. However, the membrane can be made thicker at the outer edges to increase its stiffness.

[0088] Alternatively, the membrane can be made of another material or an additional material at the outer edge to increase stiffness at the outer edge. This is in Figure 7 As shown in the diagram, thicker layers of material tend to be more rigid than thinner layers. Furthermore, the outermost portion of the membrane can be made of a more rigid material than the rest of the membrane to increase the membrane's stiffness at its outer edges.

[0089] Figure 8-13 Other types of reinforcement elements are shown, in which Figure 8 The illustration shows the addition of a thin layer, such as paper extending in the direction of movement, while... Figure 9 In this process, a layer of paper is provided, for example, extending in a direction perpendicular to the direction of movement. Alternatively, a layer of paper can be used. Figure 10 A square can also be used Figure 11 circle, Figure 12 A 45-degree square (rhombus) or Figure 13 It is a triangle with a 90-degree angle and the largest side extending in the direction of membrane movement.

[0090] Obviously, many different types and shapes of reinforcement elements can be used. Other materials can also be used to better customize performance.

Claims

1. A loudspeaker comprising a motor, a diaphragm, a surround, and a frame, wherein: - The motor is configured to move the membrane up and down along the axis. - The membrane has an outer edge. - The folding ring is connected to all the outer edges of the basin frame and the membrane. - The fold has a first portion and a second portion, wherein: - The first portion has a first radial cross-section, which extends from the third portion at the outer edge of the membrane to the point closest to the third portion of the basin stand, the first portion pointing upwards, and - The second portion has a second radial cross-section, which extends from the fourth portion at the outer edge of the membrane to the point of the holder closest to the fourth portion, and the second portion points downward. The loudspeaker further includes a reinforcing element disposed on the membrane surface at the outer edge of the membrane, wherein the reinforcing element increases the stiffness of the membrane. The portion of the folded ring between the first and second portions has an M-shaped or W-shaped cross-section.

2. The loudspeaker according to claim 1, wherein the first radial cross section and / or the second radial cross section has a U-shape or a V-shape.

3. The loudspeaker of claim 1, wherein the surround defines a repeating pattern along its central closed curve.

4. The loudspeaker of claim 1, wherein a portion of the radial cross-section of the reinforcing element has a closed curve shape.

5. The loudspeaker according to claim 4, wherein the reinforcing element is hollow.

6. The loudspeaker of claim 4, wherein the reinforcing element is filled with a filling material.

7. The loudspeaker of claim 4, wherein a portion of the reinforcing element has a polygonal radial cross-section.

8. The loudspeaker of claim 7, wherein one side of the polygon is formed by the membrane.

9. The loudspeaker according to claim 4, wherein a portion of the reinforcing element has an elliptical radial cross-section.

10. The loudspeaker of claim 1, wherein the reinforcing element forms a closed curve in a predetermined plane located at least 75% of the radius / distance to the center.

11. The loudspeaker of claim 10, wherein when projected onto the predetermined plane, the combined diaphragm and reinforcing element have a higher mass per unit area at the reinforcing element than inside the closed curve.

12. The loudspeaker of claim 1, wherein the diaphragm and the reinforcing element have a first unit area mass in a plane perpendicular to the direction of movement of the diaphragm, and the diaphragm has a second unit area mass in the plane at a position not at the reinforcing element, wherein the first unit area mass is greater than the second unit area mass.

13. The loudspeaker of claim 10, wherein the combined diaphragm and reinforcing element have a greater thickness at the reinforcing element than inside the closed curve in a direction perpendicular to the predetermined plane.

14. The loudspeaker of claim 1, wherein the reinforcing element is configured to prevent the outer edge of the membrane from bending during movement of the membrane.

15. The loudspeaker of claim 14, wherein the bending of the diaphragm is a deformation that causes a portion of the outer edge to be pulled toward the central axis of the diaphragm while other portions are pushed away from the central axis.

16. The loudspeaker of claim 10, wherein the diaphragm and the reinforcing element have a first unit area mass in a plane perpendicular to the direction of movement of the diaphragm, and the diaphragm has a second unit area mass in the plane at a position not at the reinforcing element, wherein the first unit area mass is greater than the second unit area mass, and the combined diaphragm and the reinforcing element have a greater thickness at the reinforcing element than inside the closed curve in a direction perpendicular to the predetermined plane.

17. A method for assembling a loudspeaker, the method comprising: - Provides a membrane with an outer edge. - Provide a folded ring having a first part and a second part, wherein: - The first portion has a first radial cross-section, which extends from the third portion at the outer edge of the membrane to the point closest to the third portion of the tray, the first portion pointing upwards, and - The second portion has a second radial cross-section extending from the fourth portion at the outer edge of the membrane to the point closest to the fourth portion of the frame, the second portion pointing downwards, wherein the portion of the folding ring between the first and second portions has an M-shaped or W-shaped cross-section. - Provides reinforcement components, and - Secure the outer edge of the membrane to the fold and the reinforcing element. The reinforcing element is disposed on the membrane surface at the outer edge of the membrane, and the reinforcing element increases the stiffness of the membrane.

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