RO119044B1 - Panel-shaped speaker - Google Patents

Abstract

The invention relates to a panel-shaped speaker, speaker (81) containing a radiant element (2), of a distributed type from the point of view of the acoustic resonance, on which a transducer (9) is mounted, to produce, in said radiant element (2), a distributed type acoustic resonance, the speaker (81) also containing a frame (1) which serves as a support for the radiant element (2), the transducer (9) being coupled between the radiating element (2) and the frame (1), to produce the vibration of the panel that makes up the speaker (81), thus causing the panel resonance, so that the speaker (81) produces an acoustic emission at the output, the frame (1) supporting the radiant element (2) of along its peripheral contour, by means of elastic suspension means (3) connected between the frame (1) and the peripheral contour of the radiant element (2). à

Description

The invention relates to a panel-shaped speaker, such as those comprising panel-shaped acoustic radiating elements.

It is known, from the patent application GB-A-2262861, the solution for making a panel-shaped speaker, comprising:

- a radiant element in various ways, resonant, in the form of sandwich panel, forming a unitary cellular construction consisting of two film layers of a material, separated by a core highlighted by the cross-section of the cell construction, the panel having, independently of steering, a coefficient of resistance to bending (B) equal to the mass of the panel at power 3, per unit of surface (μ), of minimum value 10;

- a mounting device, which supports the panel or secures it to a support body, freely and without cushioning;

- an electromechanical actuator device coupled to the panel and which is used to excite the resonant panel, radiant in various modes, in response to the application of an electrical signal corresponding to the working frequency band of the speaker.

US-A-3247925, Warnaka holder, discloses a speaker that is intended to be a low frequency resonant panel speaker mounted on a chassis and excited by a chassis-mounted electromechanical transducer.

In order to achieve the present invention, elements of a certain type, structure and configuration are commonly obtained and / or in particular, by applying the knowledge from the publication of PCT patent application WO97 / 09842, the applicant of which is the same as the one of the application. PCT patent which was the basis for opening the national phase of this patent application. Such elements have the capacity to maintain and propagate, by means of flexural waves, vibration energy of entry, in the operational area or zones, which, as a rule, extend transversely on thickness, and not necessarily to the edges of the respective element or elements, being configured with or without anisotropies of flexural rigidity to have resonant type vibration components, advantageously distributed, in the respective or respective areas, for acoustic coupling with the environment, having preferential locations or locations, predetermined, inside in that area, to dispose of a translator in the respective zone (s), in particular in that part or operationally active or mobile part thereof, effective in terms of acoustic vibration activity and in terms of electrical signals, as a rule, appropriate to the content the acoustics of such an activity Vibration. In the publication of the mentioned PCT patent application WO97 / 09842, the uses of such elements are presented, within devices such as passive acoustic devices without a translator, such as, for example, for reverberation, for acoustic filtering or for achieving a harmony. acoustics in a space or in a room and in acoustic devices "active with the transducer, such as, for example, those in the very wide range of acoustic or speaker sources, when they are provided with input signals, to be converted respectively in sound signal, or as are, for example, microphones, when they are exposed to a sound signal to be converted to another signal.

The present invention relates generally to active speaker-type acoustic devices, and in particular to a panel-shaped speaker.

Elements of the above are known, such as, for example, radially distributed radiant elements, the characteristics of which are in accordance with the solution described in the aforementioned PCT patent application and / or in accordance with the specific features of of the invention herein.

The invention relates to a panel-shaped diffuser, comprising an element with a peripheral contour, having the capacity to maintain and propagate, through flexural waves, vibrational input energy, in at least one active area that extends transversely over thickness, to

RO 119044 Β1 had vibrating components of resonant type, distributed over the respective area, and to have 50 preferential locations or locations, predetermined, within that area, for arranging in one of those sites or locations, a translator mounted integrally and exclusively on said radiant element, to determine the vibration of said radiant element, so that it enters the resonance, thus forming an acoustic emitter which generates an acoustic radiation when it resonates, a housing for the emitter's support around its perimeter, a the transducer coupled between the radiator and the support and an elastic suspension member coupled between the chassis, and the perimeter of the transmitter is capable of piston movement and resonant behavior, and in which the translator is adapted to move the piston transmitter. The chassis may have a portion surrounding the transmitter. The elastic suspension may be made of an elastomeric material. The chassis may comprise a lower portion having a 60 portion bound to the ground, a straight portion extending from the portion bound to the ground, and several arms extending from the right portion, the distal ends of which are connected by the arms to the chassis. surrounding the transmitter. The transmitter may be rectangular and the arms may extend close to the corners of the transmitter. The transducer can be mounted on or adjacent to the straight portion of the chassis. The transducer can be mounted on a handle in the right portion. A pair of balancing transducers can be provided. The transmitter may contain a light core, which separates a pair of light, highly modular layers.

The panel-shaped speaker, according to the invention, has the following advantages:

- has a simple, light weight construction, being easy to make;

- it allows to obtain a uniformly distributed sound from the point of view of the frequencies 70 and of a higher stereophonic effect, compared to that of the conventional loudspeakers;

- has special properties for shielding radio frequencies and reducing stationary wave effects.

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In the following, an embodiment of the invention is shown, in connection with FIGS. 1 ... 6, which represents:

- Fig. 1, constructive diagram of a distributed type diffuser, according to the description of the invention in the publication of PCT patent application WO97 / 09842;

- Fig. 2a, view through a partial cross section, following the section line A-A of fig. 1;

- Fig. 2b, a cross-sectional view, on an enlarged scale, of a radiant element 80 operating in a distributed manner, of the type shown in Fig. 2a, presented in two embodiments;

- Fig. 3a, front view of a diffuser operating in a distributed manner, according to the embodiment of the present invention;

- fig.3b, side view of the diffuser with distributed operation, of fig.3a; 85

- fig. 3c, rear view of the diffuser with distributed operation, from fig. 3a. Figure 1 shows a panel 81 speaker, of the type described in PCT patent application publication WO97 / 09842, the applicant of which is the same as the PCT patent application which was the basis for opening the national phase of of the present patent application, the diffuser 81 having a rectangular frame 1, of which some means of elastic support 3 are fixed 3, arranged around its internal peripheral contour, which support a radiant element 2, acoustically, in shape panel, distributed type (with distributed operation).

A translator 9, for example of the type that is widely presented in PCT patent application publications WO97 / 09859, WO97 / 09861, WO97 / 09859 having the same date and the same applicant as the PCT patent application, is mounted entirely and exclusively on, or within the panel radiant element 2, in a predetermined location, defined by the x and y coordinates, and whose location is calculated according to those presented in the publication of the PCT patent application W097 / 09842, mentioned above, in the purpose of producing, in the panel, a bending wave that causes its resonance to enter, in order to generate an acoustic output emission.

100

RO 119044 Β1

The transducer 9 is controlled by a signal amplifier 10, for example, an audio frequency amplifier connected to the transducer by means of conductors 28. The signal amplifier load 10 and the power requirement may be the normal ones, similar to those of conventional conical speakers, and the sensitivity is of the order of 86 ... 88 dB / watt when used in a furnished room. The load impedance of the signal amplifier 10 is largely resistive, being 6 ohms, which dissipates a power of 20 ... 80 watts. When the core and / or the film layers of the panel are metallic, they can be made to act as a heat radiator of the transducer, to evacuate the heat from the coil of the coil-motor assembly of the transducer and thus improve the energy balance. .

Figure 2a and 2b show partial cross-sections, typical for the speaker 81 of Figure 1. in FIG. 2a shows how the frame 1, the elastic suspension means 3 and the radiant element 1, in the form of a panel, are connected together, using some adhesive jointing means 20. As suitable materials for the realization of the frame 1 we mention the light structures, of type picture frames, made of extruded metal, aluminum or plastic alloy. For the elastic suspension means 3 it is advisable to use elastic materials such as, for example, rubber or plastic, both of foam type. As suitable materials for adhesive bonding means 20, we mention epoxy, acrylic, cyanoacrylate adhesives, etc.

in FIG. 2b shows, on a larger scale, the radiant element 2 in the form of a lightweight, rigid panel having a core 22, made of a rigid foam 97, made of plastic, such as, for example, cross-linked polyvinyl chloride, or a cell matrix 98 having a honeycomb structure, made of metal foil, plastic or other similar material, and whose cells are arranged transversely, relative to the plane of the panel, being closed by two film layers 21, opposite, made, for example, of paper, cardboard, plastic or sheet or sheet metal. When the film layers 21 are made of plastic, for the growth of its (Young) module, they may be fiber reinforced, in a manner known per se, the fibers being, for example, carbon, glass, Kevlar ® or the like.

Proposed materials for achieving the coating and curing film states include carbon, glass, Kevlar ®, Nomex ® meaning aramid fibers, etc., of different structures and textures, such as paper, laminated pressed paper, melamine and various coated films. high modulus (Young) synthetic plastics such as Mylar®, Kaptan®, polycarbonate, phenol, polyester or associated plastics, fiber reinforced plastics, etc. and sheets and sheets of metal. The studies and researches carried out on the Vectra class of polymeric thermoplastic materials with liquid crystals have shown that they can be used with good results for the injection molding of the coating film layers or of the ultra-thin coatings of relatively small size, for example with diameters up to about 30 cm. This material itself forms a structure with crystals oriented in the direction of injection, offering a preferential orientation for better propagation of acute energy, from the point of action to the edges of the panel.

In addition, such a technique for forming thermoplastics of the aforementioned or other types allows the assembly of forming machines to transport positioning and centering pieces, such as, for example, grooves or rings for precisely placing the parts of the transducer, such as the motor coil assembly and the magnetic suspension. Moreover, for some types of materials, less resistant, used when making the core, it is considered that it would be advantageous to increase locally, up to 150% of the diameter of the translator, the thickness of the covering film state, for example on a portion or on circular surface, in order to increase the resistance of the respective portion or surfaces and to advantageously couple the vibrational energy in the panel. In this way, by using softer sponge materials, the high frequency response is improved.

R0119044 Β1

The materials used to make the core used as a core are honeycomb shaped or have a corrugated appearance, being made from sheets or sheets made from aluminum alloys or Kevlar ®, Nomex ®, ordinary or pressed paper, and from different types of layers. films made of synthetic plastics, such as expanded or spongy plastics, or even paste materials, including metal aerogels, if they are of sufficiently low density. Some of the materials suitable for making the core used as a core have practically the property of automatically forming their coating film states at the time of manufacture and / or may have an inherent rigidity sufficient to be used between the coating film layers without requires rolling. Another material, which can be used in making the layer used as a core and having the commercial name 'Rohacell', is known for its high performance, being of the type without a covering film layer, the material can be used as a radiant panel. Basically, the aim is to obtain a material of low weight and overall rigidity corresponding to a particular application, assuming including the optimization especially of the layers used as core, of the covering film layers and of the portions between 165 these two.

Some of the preferred embodiments of such a panel use metal sheets or sheets of metal alloys, or as an alternative, use a carbon fiber reinforcement. Both of the above solutions, as well as other metal or aerogel honeycomb structures (Kevlar and carbon alloy), used as a core, have special properties of 170 radio frequency shielding, which is an element of particular importance in different EMC applications. Conical type speakers or conventional panels do not have such inherent EMC shielding properties.

In addition, it should be borne in mind that in the preferred embodiments of the invention, piezoelectric and electrodynamic transducers have electromagnetic radiation or magnetic fields of dispersion of negligible intensities. Conventional loudspeakers have large magnetic fields, which can be up to one meter apart, unless specific countermeasures are taken.

In the case of applications where good shielding is required, electrical connections can be made to the electrically conductive parts of a corresponding type 180 DML panel or to an electrically conductive foam, or an interface, similar to those used in mounting, can be used. edges.

The elastic suspension means 3 provide the damping of the edges of the panel 2 to prevent excessive displacement of the edges of the respective panel. In addition or as a displacement variant, it can also be used as a damping, for example, applying 185 panels fixed to the panel in certain preselected positions to attenuate excessive movements in order to ensure uniform distribution of the resonance throughout. panel. Such patches can be made of material made of bitumen, usually used in the enclosures of conventional speakers, or they can be made of a polymeric, laminated, elastic or rigid material. Some materials, especially paper and cardboard, as well as some materials used as a core, may have self-mitigation properties. When desired, the cushioning can be increased when making the panel, by using adhesives whose elastic hardening is in place of some rigid hardening.

A selective and efficient cushioning implies a specific application on the panel and also on the laminated material which is an integral, permanent part thereof. The edges 195 and the corners may prove particularly important for the low frequency vibration modes of the panels, which are dominant and of lower dispersion. Fixing the edges, for an element of cushioning, can usefully lead to obtaining a panel whose material, in laminated form, is completely caught on the edges, even if its corners will

EN 119044 Β1 remains relatively free, for example to allow a possible extension of operation at relatively low frequencies. The fixing can be done with the help of adhesive or even self-adhesive materials. Other useful forms of depreciation, especially when pursuing certain special effects and / or medium and high frequencies, may be in the form of one or more appropriate weights, fixed by the laminated material in certain predetermined positions, practically located medially within the respective area.

An acoustic panel of the type described above is bidirectional. The energy of the sound coming from the rear speaker is not very correlated with that of the sound coming from the front speaker. consequently, the advantage of a global summation of the acoustic power in the room is obtained, a uniformly distributed sound energy in terms of frequencies, reduced stationary wave effects and with the advantage of better reproduction, in the reproduction of sound, space and environment. naturally registered.

If the radiation emitted by an acoustic panel is largely non-directional, however, it must be taken into account that the percentage of acoustic information correlation increases outside the axis. For a better focus on artificially created stereo images, the layout of the speakers, as well as the images, at the height of a person standing has the advantage of an easy off-axis position for listeners who are usually seated, which leads to optimization of the stereo effect. In the same way, the left / right triangular geometry that includes the listener offers an additional angular component, so a good stereo effect can be achieved.

For a group of listeners there is an advantage, compared to playing using a conventional speaker. By the nature of dispersion that intrinsically characterizes the sound emission made by the acoustic panel, a volume of sound is produced that does not satisfy the dependence law inversely proportional to the square of the distance, for an equivalent point source. Due to the fact that the intensity reduction with the distance is much smaller than the one determined by applying the dependence law inversely proportional to the square of the distance, it will result that for the non-centrally located listeners, who occupy disadvantaged places, the intensity of the field for the panel type speaker will produce a stereophonic effect. superior to that of conventional speakers. This is due to the fact that the non-centrally located listener is no longer subject to double shortcomings due to the proximity to the speaker in the immediate vicinity: firstly, the excessive increase in the volume of the speaker located nearby and secondly, the corresponding reduction of the volume for the farther speaker.

There is also the advantage of a flat panel, low weight, nice looking, good looking sound quality speaker, requiring only a translator, without producing sound translations for a whole range of sounds from each diaphragm of the panel.

Fig. 3 illustrates a speaker 81, in the form of a floor-mounted panel, of the type generally described in fig. 1 and 2, and in which a light emitting array with a lightweight rigid rectangular distribution 2 is mounted on an elastic support 3, which, in turn, is placed on a rectangular support 1.

The support 1 is on a support 23 having a grounded leg 83 on a straight bar 84, having four horizontal arms 85 connected to their ends 86, at the respective corners 87 of the support 1. A pair of swing transducers 9 are mounted at one end of the panel 2, and at the other ends are also placed on the handles 88 on the bar 84, to actuate the panel.

The pair of translators 9 is located on panel 2 at predetermined locations, as discussed above. This arrangement is intended to work to steer the table 2 with the piston at low frequencies by reacting against bar 84, which, along the arms 85, acts as a chassis of a conventional drive unit.

R0119044 Β1 to the speaker and to vibrate the picture at high frequencies and make it resonate to produce 250 acoustic output sound. Such an arrangement requires the suspension 3 to be obedient, such that the roller surrounding a conical type drive of the conventional piston diffuser.

The array-shaped speaker of this invention is relatively simple to manufacture, and its component parts make it relatively easy to build. It has a wide angle of 255 acoustic dispersion compared to conventional speakers.

Claims (9)

claims 1. Panel-shaped diffuser characterized in that said speaker (81) in 260 panel-shaped comprises a radiating element having an end and being provided with the ability to maintain and propagate, through flexural waves, vibrational input energy, in at least one active area that extends transversely on the thickness, to have vibrating components of resonant type, distributed over the respective area, and to have preferential locations or locations, predetermined, within that zone, for arrangement, in one of the 265 respective locations or locations, of a transducer (9) integrally and exclusively mounted on said radiant element, to determine the vibration of said radiant element, so that it enters the resonance, thus forming an acoustic transmitter (2) that generates a radiation acoustic when resonating, the speaker (81) also including a frame (1) to support the acoustic transmitter ic (2) around its periphery, the transducer (9) 270 being coupled between the acoustic transmitter (2) and frame (1), as well as means of elastic suspension (3), coupled between the frame (1) and said end of of the acoustic transmitter (2), due to which the acoustic transmitter (2) has the ability to accompany the movement of a piston and to have a resonant behavior, the transducer (9) being adapted to allow the movement of the acoustic transmitter (2) through a movement of the piston . 275 2. Speaker according to claim 1, characterized in that the frame (1), respectively, is provided with a portion surrounding the acoustic transmitter (2). A diffuser according to claim 1 or 2, characterized in that the elastic suspension means (3) are made of a material made of elastomers. 4. Speaker according to claim 2 or 3 depending on 2, characterized in that 280, respectively, the frame (1) is provided with a foot (23) having a part (83) which comes into contact with the ground, a vertical part (84). ), which extends from the part that comes into contact with the ground, and an assembly of arms (85) that extends starting from the vertical part (84), the distal extremities of these arms (85) being linked to that part of the frame (1) surrounding the acoustic transmitter (2). 285 5. Speaker according to claim 4, characterized in that the acoustic transmitter (2) is rectangular, the arms (85) extending close to the corners of the acoustic transmitter (2). 6. Speaker according to claim 4 or 5, characterized in that the transducer (9) is mounted on the vertical side (84) of the frame (1), or in a position adjacent to it. 7. Speaker according to any one of the preceding claims, characterized in that 290 the transducer (9) is mounted on a prominent part (88), which protrudes outwardly from the vertical side (84). 8. Speaker according to any one of the preceding claims, characterized in that it comprises pair-type transducers (9) arranged in a balanced manner. 9. Speaker according to any one of the preceding claims, characterized in that 295 the acoustic transmitter (2) has a light cellular core (22), which separates even, light and highly modular layers (21).