Speaker panel

Abstract

The present application provides a method of manufacturing a resonant panel (200) of a flat panel loudspeaker. The method comprises: pressing a resonant panel blank between a first pressing surface (302) and a second pressing surface of a press, whereby to form the resonant panel (200) of the flat panel loudspeaker. The second pressing surface substantially opposes the first pressing surface (302). The first pressing surface (302) comprises at least one tool relief region (306, 312, 314, 316, 318), whereby to form at least one corresponding respective panel relief region (206, 212, 214, 216, 218) in a surface of the resonant panel (200).

Claims

1. A method of mounting a flat panel loudspeaker in a mounting surface, the flat panel loudspeaker comprising: a speaker unit comprising a resonant panel, the resonant panel comprising a front surface arranged to face outwardly in the mounting surface when the flat panel loudspeaker is mounted in the surface, the resonant panel further comprising a rear surface opposite the front surface, wherein the front surface or the rear surface has defined therein at least one depression extending inwardly within the resonant panel, the method comprising: locating the flat panel loudspeaker within a mounting opening provided in the mounting surface; applying a plaster or a jointing compound over the front surface of the resonant panel to conceal a boundary between the resonant panel and the mounting surface; and tuning an audio response of the resonant panel of the flat panel loudspeaker by selectively filling in at least one depression with the plaster or the jointing compound.

2. The method of claim 1, wherein the selectively filling in the at least one depression comprises selectively filling in the at least one depression with the plaster or jointing compound during the applying the plaster or the jointing compound over the front surface of the resonant panel.

3. The method of claim 1, wherein the at least one depression is formed by molding or pressing, and by curing during the molding or pressing.

4. The method of claim 1, wherein the front surface of the resonant panel comprises a skin.

5. The method of claim 1, wherein the front surface of the resonant panel comprises paper.

6. The method of claim 1, wherein the at least one depression extends to at least a portion of the boundary.

7. The method of claim 1, wherein the front surface of the resonant panel comprises an inner region and an outer region surrounding the inner region, and wherein the at least one depression extends from an intersection boundary between the inner region and the outer region to at least a portion of the boundary.

8. The method of claim 1, wherein the at least one depression has a substantially uniform depth.

9. The method of claim 1, wherein a depth of the at least one depression is less than 2 millimeters.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

(2) FIG. 1 is a diagram of a layer structure of a manufacturing assembly used to produce a resonant panel for a flat panel loudspeaker as disclosed herein;

(3) FIGS. 2A and 2B are illustrations of a resonant panel of a flat panel loudspeaker as disclosed herein; and

(4) FIG. 3 is an illustration of a moulding plate used to form the resonant panel shown in FIGS. 2A and 2B.

DETAILED DESCRIPTION

(5) FIG. 1 is a diagram of a layer structure of a manufacturing assembly used to produce a resonant panel for a flat panel loudspeaker as disclosed herein. The manufacturing assembly 100 is for use in a press used to form resonant panels for flat panel loudspeakers. The press comprises a first press plate 102, spaced apart from a second press plate 104. The first press plate 102 is provided with a first tool plate 106 on an inner surface thereof. The second press plate 104 is provided with a second tool plate 108 on an inner surface thereof. A pressing cavity (not shown) is defined between a first pressing surface and a second pressing surface provided by facing surfaces of the first tool plate 106 and the second tool plate 108. The pressing cavity defines a mould for forming the resonant panel of the flat panel loudspeaker. The resonant panel is formed from a resonant panel blank. The resonant panel blank is shown as the layers 110, 114, 112 between the first tool plate 106 and the second tool plate 108 in FIG. 1. The resonant panel blank comprises a first skin 110 and a second skin 112. One or more layers of pre-preg material 114 of woven or non-woven composite fibres pre-impregnated with a matrix bonding material is provided between the first skin 110 and the second skin 112. During operation of the press, the first skin 110 and the second skin 112 are each bonded to an outer surface of the one or more layers of pre-preg material 114.

(6) The first press plate 102 and the second press plate 104 are each typically heated, whereby to heat the first tool plate 106 and the second tool plate 108 during a pressing operation. In turn, this heats the resonant panel blank and promotes bonding of the first skin 110 and the second skin 112 with the outer surface of the one or more layers of pre-preg material 114 whilst also curing the pre-preg material 114.

(7) The first tool plate 106 and the second tool plate 108 are typically formed as separate plates to the first press plate 102 and the second press plate 104 respectively, but it will be understood that the first press plate 102 and the first tool plate 106 may be integrally formed as a single plate. Similarly, in some examples, the second press plate 104 and the second tool plate 108 may be integrally formed as a single plate.

(8) The exact shape of the facing surfaces of the tool plates 106, 108 is described further with reference to FIG. 3 below.

(9) The first skin 110 and the second skin 112 are each formed from a paper-based material. In this example, a thickness of the paper is approximately 0.3 mm. It will be understood that thicker or thinner paper may alternatively be used. The use of paper facilitates adhesion between the resonant panel and plaster or jointing compound used to conceal the boundary of the resonant panel when the flat panel loudspeaker is mounted in a mounting surface such as a wall. It will be understood that in some examples other materials can be used to for the skin(s), for example woven materials.

(10) The one or more layers of pre-preg material 114 is in an example a single layer of a part-cured non-woven fibre matt in a resin. The thickness of the layer of pre-preg material 114 is approximately 1 millimetres. Pressing the resonant panel blank in the press fully cures the pre-preg material 114 whereby to form a substantially solid resonant panel from the resonant panel blank. In a particular example, the pre-preg material 114 is a non-woven fibre glass matt comprising a part-cured resin suspending the matt of glass fibres. Prior to full curing, the pre-preg material is malleable and tacky. It will be understood that the pre-preg material could use other fibres instead of glass fibres, for example carbon fibre, carbon nano tubes, or organic materials such as fibres from plants such as cotton or flax.

(11) In some examples, the one or more layers of pre-preg material 114 comprises a plurality of layers of pre-preg material. At least one of the plurality of layers of pre-preg material can be a wover layer of pre-preg material. A woven material typically expands less than a non-woven layer of pre-preg material during curing. Furthermore, a woven layer of pre-preg material may be stiffer than the non-woven later of pre-preg material.

(12) To prepare the pre-preg material 114, a liquid phenolic resin is poured over the non woven fibre matt described previously. The material mixture is partially cured in a first stage curing process by heating the material at a predetermined temperature for a predetermined time. Following this, the pre-preg material is malleable, but tacky, and may be stored in this state for a number of days, for example in a cooled environment. It will be understood that alternative resins can be used such as melamine based resins to form the pre-preg material.

(13) Once the form of the panel is created by pressing, it can be cured to form a stiff, lightweight board by heating in an autoclave or press. After this, the panel may be finished (e.g. the edges may be trimmed) and mounted to the exciter and chassis structure (not shown) components to assemble the flat panel loudspeaker.

(14) FIGS. 2A and 2B are illustrations of a resonant panel of a flat panel loudspeaker as disclosed herein, viewed from different perspectives. The resonant panel 200 was formed using the manufacturing assembly 100 described previously with reference to FIG. 1. The resonant panel 200 comprises a front surface 202 to face substantially outwards from a mounting surface when the flat panel loudspeaker is mounted in the mounting surface. The front surface 202 comprises an inner region 204 and an outer region 206. The outer region 206 surrounds the inner region 204. The outer region 206 borders the inner region 204 at an interface 208. The outer region 206 extends outwards from the interface 208 to a resonant panel boundary 210. The outer region 206 is formed to have a low relief compared to the inner region 204. It will be understood that this can alternatively be expressed as the inner region 204 being formed to have high relief compared to the outer region 206. Within the inner region 204 there are defined a plurality of localised surface features 212, 214, 216, 218. In this example, all of the localised surface features 212, 214, 216, 218 are shown having low relief relative to the inner region 204, but it will be understood that some or all of the localised surface features could be formed to have high relief relative to the inner region 204. In particular, the plurality of localised surface features include a word “LOGO” surface feature 212 positioned in a lower left region of the inner region 204. The word surface feature 212 is a depression extending within the front surface 202 of the resonant panel 200 to a maximum depth of 2 millimetres. An innermost surface of the word surface feature 212 is rounded. A rectangular-shaped surface feature 214 is provided in a centre-right region of the inner region 204. The rectangular-shaped surface feature 214 is positioned such that a longitudinal length of the rectangular-shaped surface feature 214 extends along a right side of the inner region 204. The rectangular-shaped surface feature 214 is a depression extending within the front surface 202 of the resonant panel 200 to a uniform depth of 2 millimetres. A first oval-shaped surface feature 216 is provided in a centre-top region of the inner region 204. The first oval-shaped surface feature 216 is a depression extending within the front surface 202 of the resonant panel 200 to a uniform depth of 2 millimetres. A second oval-shaped surface feature 218 is provided in a centre-right region of the inner region 204. The second oval-shaped surface feature 218 is a depression extending within the front surface 202 of the resonant panel 200 to a uniform depth of 2 millimetres. It will be understood that more or fewer localised surface features may be provided on the resonant panel 200, in particular on the front surface 202 of the resonant panel 200, and more particularly in the inner region 204 of the front surface 202.

(15) It will be understood that although the example discusses a uniform depth of 2 millimetres for the rectangular-shaped surface feature 214, the first oval-shaped surface feature 216 and the second oval-shaped surface feature 218, the depth may be anywhere from 0.5 millimetres to 2 millimetres.

(16) When the localised surface features are depressions extending within the surfaces of the resonant panel 200, the location, shape, and size of the localised surface features can be chosen specifically to provide a predetermined effect to the audio response of the resonant panel 200 when the depressions are filled. In the present example, the depressions are designed to be filled with plaster, having a known density. However, it will be understood that the depressions could instead be configured to be filled with other materials, or with a range of materials, in order to produce a predetermined and desired tuning of the audio response of the resonant panel 200.

(17) In this example, a rear surface (not shown) of the resonant panel 200 is substantially planar and devoid of localised surface features. It will be understood that the rear surface of the resonant panel 200 may comprise localised surface features for use in tuning the audio response of the resonant panel 200 as described previously.

(18) In some embodiments, the localised surface features are intended to have a minimal effect on the audio response of the resonant panel 200, but are intended to allow the location of the resonant panel within the mounting surface to be observed for a period after mounting. Where the localised surface features are depressions, an installer may then fill in the depressions once further works have been completed to the mounting surface in which the flat panel loudspeaker is located. In this way, the depressions can be selectively filled in to substantially selectively hide the flat panel loudspeaker within the mounting surface. For example, an installer may need to install a mounting bracket for a television into a wall surface.

(19) FIG. 3 is an illustration of a moulding plate used to form the resonant panel shown in FIGS. 2A and 2B. It will be understood that the features of the moulding plate 300 correspond substantially to the features of the resonant panel described previously. The moulding plate 300 may take the place of either of the first tool plate 106 or the second tool plate 108 described with reference to FIG. 1 previously. The moulding plate 300 comprises a first pressing surface 302. The first pressing surface 302 comprises an inner region 304 and an outer region 306. The outer region 306 surrounds the inner region 304. The outer region 306 borders the inner region 304 at an interface 308. The outer region 306 extends outwards from the interface 308 to a moulding plate boundary 310. The outer region 306 is formed to have a high relief compared to the inner region 304. It will be understood that this can alternatively be expressed as the inner region 304 being formed to have a low relief compared to the outer region 306. Within the inner region 304 there are defined a plurality of localised surface features 312, 314, 316, 318. In this example, all of the localised surface features 312, 314, 316, 318 are shown having high relief relative to the inner region 304 in order to conform to the resonant panel 200 shown in FIGS. 2A and 2B. Specific features of the localised surface features 312, 314, 316, 318 are substantially as described in relation to the localised surface features in FIGS. 2A and 2B but for the fact that the localised surface features 312, 314, 316, 318 are described in the opposite sense whereby to be usable to form the resonant panel when the moulding plate 300 is used to press into a malleable resonant panel blank as described previously.

(20) In summary, the present application provides a method of manufacturing a resonant panel (200) of a flat panel loudspeaker. The method comprises: pressing a resonant panel blank between a first pressing surface (302) and a second pressing surface of a press, whereby to form the resonant panel (200) of the flat panel loudspeaker. The second pressing surface substantially opposes the first pressing surface (302). The first pressing surface (302) comprises at least one tool relief region (306, 312, 314, 316, 318), whereby to form at least one corresponding respective panel relief region (206, 212, 214, 216, 218) in a surface of the resonant panel (200).

(21) Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

(22) Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the disclosure are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The extent of the disclosure is not restricted to the details of any foregoing embodiments. The extent of the disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.