EP4026116A1 - Electronic piano - Google Patents

Abstract

Electronic piano comprising a housing (1), a keyboard (7) comprising a plurality of mechanically actuated keys, and a loudspeaker (6) able to generate acoustic vibrations, which are at least partially received in said housing (1), said piano being characterized in that it further comprises a vibrational transfer member (2) able to transfer the vibrations emitted by the loudspeaker (6) toward the keyboard (7), this vibrational transfer member (2) comprising a front transverse zone, intended for supporting the keyboard, and a rear transverse zone intended to accommodate the loudspeaker (6), said front and rear zones respectively being connected to one another in such a way that at least a substantial proportion of the vibrations generated by the loudspeaker (6), in the region of the rear zone, are transmitted toward the keyboard (7) situated in the front zone.

Description

ELECTRONIC PIANO Technical field of the invention

The invention belongs to the technical field of electronic pianos, in which the sound, caused by the operation of the keyboard, is generated by a digital processor associated with an acoustic speaker. Such an electronic piano can imitate the sound of an acoustic piano.

State of the art

In an electronic piano the sound is generated electronically; such a piano does not have strings made to vibrate by the operation of the keys, but the keys are provided with sensors which transmit a signal to an electronic component that is part of an electronic system which generates an analog electrical signal transmitted to a high -speaker, which can be integrated into the piano or external. The integration of speakers into the keyboard housing is known from US 5,308,937 (Kabushiki Kashia Kawai Gakki), and many commercial instruments have speakers which are integrated into the electronic keyboard housing.

There are electronic pianos whose sound quality and feel are quite close to those of acoustic pianos (ie in which the sound is generated by the action of a hammer which is projected on one or more strings when the pianist presses a key. ) small or medium in size, including good quality upright pianos; these electronic instruments are commercially available. It has now appeared the desire to have an electronic piano which presents both the same quality of sound reproduction, the same possibilities of mastering the sound by the touch of the pianist, and the same acoustic and tactile sensations felt by the pianist, than the best concert grand pianos. Such an electronic piano does not yet exist; it is hoped that it may be cheaper and easier to transport than a concert grand piano, which can be over 2.6 meters long and weigh over 450 kg.

The tactile sensations felt by the pianist depend, on the one hand, on the keyboard itself, ie on the construction, the mass, the pressing movement, the limit switch and the return movement of the keys, and, of on the other hand, by vibrations that the instrument as a whole transmits to the keys, which are, apart from the pedals, the only point of material contact between the pianist and his instrument. These vibrations, perceived by the pianist first at the tips of his fingers which are the points of contact with the keys of the keyboard, can then be felt in other parts of the finger, and can propagate in different parts of the hand and of the arm. It is a global sensation, due to the setting in vibration of the whole structure of the piano. For a very high level player, this vibrational feedback is complementary information (compared to the acoustic rendering which constitutes the main information) quite interesting and exploitable, and can also be a source of pleasure.

Thus, the absence of vibrations transmitted by the instrument to the keyboard is normally noticeable only to a good pianist who has played high quality acoustic pianos. This lack has become apparent as the sound quality reproduction of electronic pianos has improved enough for electronic pianos to be of interest to very good pianists. The state of the art presents several approaches.

US 5,189,242 (Yamaha) describes an electronic piano in which the keyboard is placed on a resonance plate which can be vibrated by an electric vibration generator. These vibrations are transmitted to the keyboard. However, these vibrations are not generated by the sound as it is generated by the piano under the action of the pianist; the pianist will therefore not have the same feeling of vibrational feedback in relation to the sound he has just produced as on a good quality acoustic piano.

US 2010/0147 132 and US 2010/0147 131 (Yamaha) describe an electronic piano which takes the form of a grand piano (of so-called "quarter-grand" size), and which is provided with a resonance plate. JP 2011/043611 (Yamaha) describes an electronic piano in which the keyboard is mounted in a complex structure formed of folded and screwed sheets, which transmits vibrations generated by a vibrator to the keyboard box and the keyboard. Mechanically this structure is very complex.

The problem that the present invention seeks to solve is to present an electronic piano of excellent acoustic quality, comparable to that of a piano. concert tail, which ensures a vibrational transfer to the whole structure and to the keyboard, with a result felt by the pianist which is comparable to that obtained on an excellent acoustic piano, and which is easy to manufacture and to assemble.

Objects of the invention

According to the invention, the problem is solved by integrating the various functions of the keyboard support structure in an organ, called vibrational transfer, on which the keyboard is fixed, directly or by means of a support plate. , and in which is inserted at least one loudspeaker. Said vibrational transfer member is in particular a section, which can be a metal section (for example an extruded section of aluminum alloy), or a section of non-metallic material (for example carbon fiber). The combination of these means ensures good transfer of vibrations from the loudspeaker to the structure.

Thus, a first object of the invention is an electronic piano comprising a housing or housing, a keyboard comprising a plurality of mechanically actuated keys, and at least one loudspeaker capable of generating acoustic vibrations, which are at least partially received. in said housing, as well as at least one digital processor capable of processing the signals coming from the keys and of generating signals transmitted to said at least one loudspeaker, said piano being characterized in that it further comprises a control member vibrational transfer, which is capable of transferring the vibrations emitted by the loudspeaker towards the keyboard, this vibrational transfer member comprising a front transverse zone, with reference to the user in a playing situation, intended for receiving the keyboard, and a rear transverse zone, in which is received at least one loudspeaker, said respectively front and rear zones being mutually connected by mechanical means, so rte that at least a part, preferably substantial, of the vibrations generated by the loudspeaker, at the level of the rear zone, are transmitted in the direction of the keyboard located at the level of the front zone. Advantageously, the vibrational transfer member is separate from the housing. In particular, the transfer member and the housing can be made of different materials. This makes it possible to separate the respective functions, which gives them improved efficiency. In this spirit, it is possible to provide means for fixing this transfer member to the housing.

According to one embodiment, the vibrational transfer member may be metallic, which is advantageous in view of the intended function.

According to an advantageous embodiment, the vibrational transfer member comprises a profile, in particular metallic, this vibrational transfer member being in particular formed by said profile. In particular, this profile can be produced by extrusion.

According to another advantageous embodiment, this section is closed laterally by at least one flange.

According to another advantageous embodiment, the rear transverse zone, in which the loudspeaker is received, is open upwards. In this way, the loudspeaker can broadcast the sound upwards.

Said transverse zones front and rear respectively can be made in one piece, in the transverse direction of the transfer member.

In one embodiment, the respectively front and rear zones belong to respectively front and rear parts of the transfer member, and fixing means are provided between these parts, these fixing means making it possible to ensure vibrational continuity. between said front and rear parts.

Advantageously, the reception zone arranged in the vibrational transfer member comprises a chamber which can be open upwards and / or laterally, and which may in particular have a U-shaped cross section. This chamber can accommodate a loudspeaker. . Means for mounting the or each loudspeaker on the walls of the chamber may be provided, in particular at least one mounting member of the flange type. Sealing means can be provided between the interior volume of the chamber and the exterior of this chamber. The keyboard can be fixed on said front zone of the vibrational transfer member with securing means. Said front area may include a keyboard support pad. Advantageously, the keyboard support pad extends over a major part of said front transverse zone. In this way, the fixing of the keyboard is made more convenient and more secure. In a further variant, there is provided an intermediate mounting plate, fixed to said pad, the keyboard being secured to this intermediate plate.

The vibrational transfer to the structure and the keyboard can be further enhanced by the use of a speaker built into a sealed speaker enclosure. Advantageously, the volume of said enclosure is undersized in terms of air volume. Preferably, two loudspeakers are inserted into the profile, one on the left and one on the right; this makes a spatialized sound like on an acoustic piano.

In a very advantageous embodiment, said hermetic loudspeaker enclosure is undersized in terms of air volume, and advantageously has a total overvoltage coefficient of at least 0.75, preferably of at least 0.90, more preferably at least 1.1 or 1.2, and even more preferably between 0.90 and 1.5.

According to another embodiment, the keyboard housing rests, preferably in a fixed or removable manner, on a base, such as a foot. One or more additional loudspeakers can be integrated into this base. At least one of these additional speakers can be a bass speaker. The presence of a speaker in the base further improves the vibrational transfer and makes it more realistic for the pianist, comparable to a concert piano. Advantageously, this is a hermetic loudspeaker, the enclosure of which can be undersized.

The electronic piano according to the invention can be made in a collapsible manner. In this case the keyboard housing comprises at least two, and preferably three, sections in its longitudinal direction, to be foldable. More precisely, the vibrational transfer member is formed of at least two sections. Thus, each of the sections of the housing comprises a section of said vibrational transfer member, which is one of the essential means of the present invention. Of them adjacent or contiguous sections of said vibrational transfer member (which is typically a section) are connected by a mobile, removable or foldable mechanical connection means, which may be of the hinge type; this means must ensure, in the unfolded state, a rigid mechanical connection between the two sections of the profile. According to the invention, said mechanical connecting element must also ensure a vibrational transfer from the (section (or sections) provided with a loudspeaker to the section (or sections) not provided with a speaker. In order to improve the vibrational transfer, mobile assembly elements can be added in the plane of the keyboard.

Each section of the profile can be in one piece, or it can be assembled in its width from two or more profiles, in particular by clipping, screwing, gluing, welding between two profiles; we prefer to make the profile in one piece.

The vibrational transfer is modified, and in particular damped, by a covering of the profile to form a keyboard box, knowing that the speed of sound propagation is different in the air, in the covering material (typically wood), and in metal. More precisely, the metal profile ensures the vibrational transfer from the speaker enclosure to the keyboard, while the casing dampens the vibrational transfer of the metal profile in the air to ensure a more "round" and "deep" sound. and to avoid resonance peaks that are perceived as unpleasant (“metallic sound”).

This covering is advantageously made of wood or of synthetic material, for example of carbon fiber composite; it can be achieved by assembling elements according to known techniques for piano makers. A wooden cladding is typically assembled from several panels of simple shape, whereas a synthetic material cladding can take a more complex shape, such as a shell shape. This cushioning helps achieve a feel as close as possible to that of an acoustic concert piano.

According to another embodiment, said metal profile is embedded in a wooden or polymer shell, which makes it possible to generate acoustic resonance phenomena more effectively in the housing. Another object of the invention is an electronic piano comprising a foldable casing or casing, comprising at least two sections in its longitudinal direction, a keyboard comprising a plurality of mechanically actuated keys, and at least one loudspeaker capable of generating acoustic vibrations, which are at least partially received in said housing, as well as at least one digital processor capable of processing the signals coming from the keys and of generating signals transmitted to said at least one loudspeaker, said piano being characterized in that that it further comprises a vibrational transfer member, which is able to transfer the vibrations emitted by the loudspeaker in the direction of the keyboard, said vibrational transfer member being formed of at least two sections, each section having at least over its side facing with an adjoining section a flange. In the unfolded state of the piano, said contiguous flanges come into mechanical contact. This strengthens the vibrational transfer between the different sections. In one embodiment, each section of this vibrational transfer member comprises a front transverse zone, with reference to the user in a playing situation, intended to receive the keyboard, and a rear transverse zone, in which at least is received. a loudspeaker, said respectively front and rear zones being mutually connected by mechanical means, so that at least a part, preferably substantial, of the vibrations generated by the loudspeaker, at the level of the rear zone, are transmitted towards the keypad located in the front area.

Brief description of the figures

The invention will be described below, with reference to the accompanying drawings, given solely by way of non-limiting examples, in which:

[Fig. 1] is a perspective view, illustrating an electronic piano according to one embodiment of the invention.

[Fig. 2] is a perspective view, more particularly illustrating the upper part of this piano.

[Fig. 3] is a perspective view, more particularly illustrating certain mechanical elements located inside the case of this piano. [Fig. 4] is a perspective view, more particularly illustrating a vibrational transfer profile received in this housing.

[Fig. 5] is a perspective view, with longitudinal section, illustrating in more detail the cooperation between the profile of Figure 4, as well as a speaker and the piano keyboard. [Fig. 6] is a longitudinal sectional view illustrating the various mechanical elements shown in FIG. 5.

[Fig. 7] is a perspective view, more particularly illustrating a base belonging to this piano.

The following reference numerals are used in the present description. 1 box; 2 organ (profiled) of vibrational transfer;

6 speakers; 7 keyboard; 8 digital processor; 9 base;

10 case back; 11, 12 front and rear walls of the housing;

13.14 side walls of the housing; 15 upper walls of the housing;

16 opening in the wall 15; 20 front zone of the profile; 22 beach; 24 front angle; 26 screws; 28 alveoli;

40 rear area of the profile; 42 room; 42a 42b longitudinal end of 42;

44 soul of 42; 46.48 wings of 42;

50 retracting shoulder; 52 chute; 53 scope; 54 fixing screws; 56 boxes; 60 mounting flange of 6; 63 opening in 60; 64 collar of 6; 65 fixing screws; 66676869 housing edges; 72 fixing plate of 7 compared to 20; 74 additional profile;

76 back from 74; 78 rib of 74;

80 reception accommodation of 8; 82 hood of 80; 83 adjustment buttons of 82; 84.86 grids; 88 cache; 90, 92 side feet of 9; 91, 93 enclosures of 90, 92;

94, 95 openings of 91, 93; 96, 97 loudspeakers from 91, 93; 99 crosses;

100 flask; 101 front part of 100; 102 rear part of 100 103 hole for passage of a fixing screw 105 protuberance; 106 opening XX YY axes and directions respectively longitudinal (e) and transverse (e) of the piano and the section;

I piano

Detailed description The electronic piano according to the invention, which is illustrated in the accompanying figures being assigned the reference I, essentially comprises the following mechanical elements: a body 1 forming a housing, a keyboard 7, a digital processor 8, at least a loudspeaker 6, a profile 2 ensuring the vibrational transfer between the keyboard and the loudspeaker, as well as a base 9. By convention, we note, in particular in Figures 1 and 4, XX and YY the respectively longitudinal directions and transverse of the piano according to the invention. XX corresponds to the largest dimension of this piano (and more precisely to box 1), while YY corresponds to the smallest of these dimensions. XX and YY also correspond to respectively longitudinal and transverse directions of the section 2. In particular the direction XX corresponds to the direction of extrusion of this section.

These directions XX and YY are also associated with respectively longitudinal and transverse axes of this piano. We note in the figures AV and AR the transverse parts respectively front and rear of this piano, with reference to the position of the user in a game situation. In other words, the front part is adjacent to the user, while the rear part is opposite to him.

As can be seen in figure 1. the housing 1, which has a substantially parallelepipedal shape, has a bottom 10 bordered by peripheral walls. The latter comprise front walls 11 and rear 12, respectively, as well as side walls 13, 14. Finally, we note the upper wall, which is hollowed out with an opening 16 which extends over a large part of its surface to give access to the keys of the keyboard 7. In a non-limiting way, the material constituting this housing 1 is for example wood. However, as a variant, provision can be made for this housing 1 to be made, at least in part, of synthetic materials, for example of composite materials (in particular of the type comprising carbon fibers), and / or of polymeric material.

The box 1 rests on the base 9, the structure of which will be explained in greater detail below in relation to FIG. 7.

As can be seen in Figure 4. the profile 2 extends between the side walls 13 and 14 of the housing.

The cross section of this profile 2 typically has a substantially constant shape, along its longitudinal axis XX. By way of nonlimiting examples, this profile can first of all be made of a metallic material, such as aluminum or an aluminum alloy (for example an alloy of the Al-Mg-Si type, the alloys of this type. type also known under the designation 6xxx), or steel.

A profile produced by extrusion is very advantageously used, and not a profile obtained by bending sheets; extrusion (also called spinning) is a process which makes it possible to produce sections with a fairly complex cross-section by a relatively simple industrial process. As a variant, provision can be made for this profile to be made of a non-metallic material, in particular of a composite material (in particular of the type comprising carbon fibers) or of a plastic material.

Extrusion leads to sections of constant shape along their long axis (direction of extrusion). It is possible to work this extruded section by machining and / or by deformation to obtain a section whose shape is not constant along its long axis. It is also possible to use folded profiles, in particular manufactured from from sheets, and / or welded sections; this involves additional process steps.

This profile 2 first of all has a so-called front zone 20, turned towards the user in a playing situation, which is intended for the support of the keyboard 7. This zone 20 is formed by a range 22, from which extends a front angle 24, allowing the fixing of a screw 26 on the wall 11 of the housing. Immediately below the pad 22, different cells 28 are provided (visible in Figure 6). Their function is to give sufficient mechanical strength to this part of the profile, in particular to enable it to support the mass of the keyboard without noticeable deformation. In particular, as shown in Figure 6, provision can be made to use screws 30 for fixing the profile to the bottom 10 of the housing.

As can be seen in particular in FIGS. 4 and 5. the aforementioned front zone is extended by a rear zone 40, first of all comprising a chamber 42 (also called “rear chamber”) in the form of a U. This chamber 42 is formed of a core 44, as well as two wings 46 and 48. One of its wings is provided with a re-entrant shoulder 50, while the other wing is extended radially outwards through the intermediary of a chute 52, allowing the passage of a screw 54 for fixing to the wall 13. This chute further defines a bearing surface 53, the function of which will be described below. Furthermore, in the extension of the cells 28 along the transverse axis, several boxes 56 separated by stiffeners are provided below the chamber. These boxes 56 in particular allow attachment to the bottom 10 of the housing, in the example illustrated by means of screws 58. They also have the function of stiffening the bottom 44 of the U-shaped structure.

The wings 46,48 of the U-shaped structure, on the other hand, can be vibrated directly by the loudspeaker; their vibrations are transmitted to the bottom 44 then to the pad 22 and to the angle bar 24 which, for their part, transmit them to the keys.

The chamber 42 may include a cover made of wood, metal, or plastic materials, or a combination of several materials.

The box comprises two loudspeakers 6, one on the right part of the box 1, the other on the left part. Each loudspeaker 6 is mounted on the section 2, at the level of a longitudinal end 42a or 42b of the chamber 42, by means of a respective flange 60. In more detail, this flange 60 has an outer shape of a quadrilateral, corresponding to the shape of the upper part of the chamber of this profile. Furthermore, this flange 60 is hollowed out with a central opening 63, allowing the passage of the loudspeaker 6. The latter comprises a collar 64, allowing the loudspeaker to rest against the periphery of this opening 63. Screws 65 allow a removable fixing of both the flange 60 and the loudspeaker, relative to the profile 2. To this end, these screws cooperate with the shoulder 50 described above. Thus, the loudspeaker 6 is embedded in the rear chamber 42 of the section 2. This chamber forms a resonance chamber which extends over the entire longitudinal dimension of the section 2. Said flange 60 can be made of a metallic material, for example. example in stainless steel or aluminum alloy.

At least part of the covering elements which form the box 1, and which can be made of wood and / or synthetic material, are advantageously in contact with the walls of this rear chamber 42: this improves the fidelity of the sound rendered by the electronic piano according to the invention.

As shown in particular in Figure 3. the housing is provided with several flanges, which extend transversely along the YY axis. First two ledges

66, 67 are first provided, adjacent to a respective side wall 13,14 of the housing. Furthermore, two additional rims 68, 69 are provided at a distance from each rim above. Each pair of edges, respectively 66, 68 and

67, 69, is mutually spaced a distance corresponding substantially to the dimension of each flange 60, longitudinally along axis XX. It is also possible to provide sealing means interposed between the walls facing the flange and this rim.

The keyboard 7 can be of any type known per se, is advantageously a mechanical keyboard, provided with keys which sink under the pressure exerted by the finger on the pianist. This keyboard 7 is secured to the area 20 of the profile, thanks to an intermediate plate 72. Furthermore, an additional profile 74 is provided, which is fixed to the keypad. This profile 74 is provided with a U-shaped return 76, as well as an end rib 78. This return and this rib allow the fixing of both the plate 72 and the keyboard 7, relative to the profile. 2, thanks to additional screws 78. All the assemblies which have just been described are produced by mechanical assembly means, typically by snap-fastening, screwing or riveting.

Said intermediate plate 72 is optional; it has several advantages. It acts as a stiffener for the structure of the housing 1, it facilitates the assembly of the keyboard 7 on the vibrational transfer member 2, it promotes the vibrational transfer.

An aluminum alloy rolled sheet plate may be used, preferably an age hardening alloy, even more preferably in a dissolved and tempered state. As such, it is possible to use, for example, a sheet made of an alloy of the Al-Zn-Mg-Cu type.

The digital processor 8 can be of any type known per se. This processor is received in a middle slot 80, with reference to the YY axis. This housing 80 is bordered, on either side, by the edges 67 and 69, as well as the walls facing the flanges 60. The processor 8 is connected, by any appropriate means, to both the speaker and the keyboard. . These different connections, which are of a type known per se, are not detailed in what follows.

The receiving housing of the processor is covered by means of a cover 82. The latter may include one or more adjustment buttons 83, of a type known per se; this may include adjusting the sound volume.

Furthermore, the upper face of each loudspeaker 6 is covered by a grid 84, 86 which is fixed to a respective flange by any suitable means, in particular by screwing. Finally, a cover 88, of elongated shape, extends along the YY axis between the keyboard and the rear area of the case.

As can be seen in FIG. 7. the base 9, fitted to the piano according to the invention, first of all comprises side feet 90, 92. The bottom 10 of the case rests on the top of these feet, being fixed. on the latter by any appropriate means, in particular removably. The internal face of each leg, namely that which faces the opposite leg, supports a respective enclosure 91, 93. Each enclosure delimits a central opening 94, 95, intended for the reception of a respective loudspeaker 96, 97 Each loudspeaker is fixed around the periphery of its receiving opening, by any suitable means such as for example screws. Finally the feet 90 and 92 are mutually connected, at the level of their rear zone, by a cross member 99. The loudspeaker (s) 96, 97 located in the side feet are typically intended for low frequencies.

Alternatively, a single loudspeaker can be provided in the base. In this case said loudspeaker is preferably arranged so that it sends the sound waves onto a flat surface (typically on the opposite foot) to generate sound bounces. More precisely, said loudspeaker can be mounted on an internal surface of one side of said base, and the internal face opposite to said loudspeaker has a flat surface, so that the sound waves emitted by the membrane of said loudspeaker speaker can be returned by said flat surface.

In the present embodiment, the housing is foldable, that is to say the housing, the profile and the keyboard are each formed by three sections, placed one behind the other longitudinally along the axis XX. In the figures, these different sections are referenced 1A to 1C, 2A to 2C as well as 7A to 7C. More specifically, there is a fixed central section, as well as end sections, which are provided on either side of the central section. Preferably, the two mobile sections 1A, 1C, 2A, 2C, 7A, 7C have the same length, which is at most equal to half the length of the central section 1B, 2B, 7B. In this way, when the piano is folded up, the outer edges of the movable sections are mutually adjacent.

In order to allow such an embodiment, the piano is equipped with reversible mechanical fixing means provided at the junction between the facing edges of the central section and a respective end section. The reversibility of these fasteners allows the user to easily fold and unfold the housing, preferably without tools.

These reversible fixing means can be hinges. By way of nonlimiting examples, these articulation hinges are for example in accordance with those which are described in WO 2018/185841 in the name of the applicant. Obviously, other hinge structures can be provided and more generally other reversible mechanical fastening means, for example snap-fastening means, or even magnetic means. It has been seen above that, in the present embodiment, the section 2 is produced in three sections, along its longitudinal direction XX. Within each section, this section 2 is produced in one piece, in its transverse direction YY. This allows a satisfactory transfer of vibrations from the loudspeaker 6 towards the keyboard 7. On the one hand, the mechanical fastening means contribute to the vibrational transfer between the various sections of the profile 2, as well as between the various sections of the section. section 2 and the housing 1. On the other hand, the mechanical fixing of the keyboard 7 on the section 2 ensures the vibrational transfer of the section to the keyboard. These vibrations originate in the loudspeakers 6 integrated in the section 2 (in the case of a foldable box with three sections: typically in the right section and the left section); they are transferred from the loudspeakers 6 to the profile 2, then to the walls of the box 1, and finally to the keyboard 7.

As a variant (not shown in the figures), provision can be made for the housing 1 to have only two sections, or a single section (in the latter case it is not foldable).

According to the invention, the vibration transfer member is produced in the form of a section 2, which is received in a housing 1. This is advantageous, in particular in terms of simplicity of manufacture. It is this vibration transfer member 2 which ensures for a significant part the transfer of the vibrations of the sound generated by the speakers 6 integrated in the housing 1 to the keyboard 7, which is also received in said housing 1. The material constituting said housing contributes to the vibrational transfer of the sound generated by the loudspeaker to the keyboard. This transfer is also done by air, and this is more efficient if the housing is closed, as is the case in the embodiments shown in the figures.

According to another aspect of the invention, which is illustrated in Figures 8 and 9, the vibrational transfer member 2 (which is advantageously a profile) comprises on its lateral sides a flange 100. This is described here by way of illustration for an advantageous embodiment of the electronic piano according to the invention to which reference has already been made above, in which the housing 1 comprises three sections. In this embodiment, each box section has a section 2 section. Advantageously, the central section of the section is closed on each side. by a flange, and at least the left side of the right section and the right side of the left section are also closed by a flange.

Said flange 100 is typically a piece machined from thin sheet metal. Advantageously, the outer contours of the flange has a shape which allows it to be embedded at least partially in the profile 2: its shape must allow lateral insertion into the profile. The flange therefore comprises a front part 101 and a rear part 102. It is fixed using a plurality of screws; the reference numeral 103 designates holes made in the flange to accommodate these screws. The flanges must not create too great a gap between the two contiguous keys which are separated by two contiguous flanges. The flanges are advantageously made of sheet metal with a thickness not exceeding 1.0 mm, and preferably not exceeding 0.6 mm. They must, however, be sufficiently rigid.

Said flanges 100 perform three functions. First, when the case is unfolded and ready to be used by a pianist, the flanges help to stiffen the profile 2 in the direction of its main mechanical stress, i.e. in the vertical direction.

Second, when the case is folded up and ready for use by a pianist, the two adjoining flanges touch each other. This mechanical contact can be promoted by a set of removable fixing members 105,106 designed to cooperate, such as a protuberance 105 which cooperates with an opening 106 (for example male / female type fasteners). This mechanical contact ensures a more efficient vibrational transfer between the section (s) provided with a loudspeaker and the section which is not provided with a loudspeaker (ie, in the case of a three-section keyboard such as illustrated in Figure 2, between the movable sections 1A and 1C and the central section 1B).

On the other hand, when the foldable case is folded, the flanges 100 hide the interior of the cases, which has an aesthetic function; the end shields also protect the housing against dust and the ingress of objects.

The flanges may have openings (not shown in the figures) to allow the passage of electrical connection elements. According to yet another aspect of the invention, the loudspeaker enclosure 6 is a closed enclosure (such enclosures are also known under the name “hermetic enclosure”). Advantageously, it is undersized, that is to say its air volume is such that its total overvoltage coefficient is greater than 0.707. This undersizing in air volume forces a significant part of the sound power to flow through the structure of the piano (in this case, through the profile) and not by the air set in vibration by the upper membrane. -speaker.

The inventors have found that the surge coefficient can be significantly greater than 1.1. By way of example, an electronic piano has been produced according to the invention having speakers integrated into the profile 2 with a surge coefficient of approximately 1.37. More generally, the surge coefficient is advantageously between 1, 1 and 1, 5. Preferably, the orientation of the speakers recessed in the profile 2 is such that the vibrating membrane is located horizontally so that the emission of the sone is upwards; however, an inclination can also be provided.

As indicated above, it is advantageous to add to the speaker built into the profile 2 (or to the two speakers built into the profile) a third (or even a fourth) speaker dedicated to low frequencies; this loudspeaker can be integrated into the base of the piano. This improves both the sound rendered by the piano and the vibrational transfer to the keyboard. You can only use one speaker in the base.

By way of example, an electronic piano according to the invention has been produced with two identical loudspeakers 6, embedded in the profile 2, each comprising a closed enclosure, said loudspeaker being designed to function optimally with an enclosure. closed with a volume of 3.7 liters, while the volume of the closed enclosure in the electronic piano according to the invention was only 2.7 liters. A very satisfactory vibrational transfer was obtained, even in the case where the section 2 comprised three sections mechanically connected by hinges; in this case, the section comprised four flanges 100 between the movable sections 1 A and 1 C and the central section 1 B).

The electronic piano according to the invention advantageously comprises a plurality of pedals, which advantageously form a block called a pedal (not shown in the figures). These pedals have at least the same sound functions as in an acoustic piano, but can be configured to have additional functions. Said pedal can be mechanically connected to the base so as to transfer the vibrations from the base to the pedal, in order to restore a sensation similar to those of acoustic concert pianos.

Claims

1. Electronic piano including • a box (1) or casing, • a keyboard (7) comprising a plurality of mechanically actuated keys, and • at least one loudspeaker (6) capable of generating acoustic vibrations, which are at least partially received in said housing (1), as well as at least one digital processor capable of processing the signals coming from the keys and of generating signals transmitted to said at least one loudspeaker (6), said piano being characterized in that it further comprises a vibrational transfer member (2), able to transfer the vibrations emitted by the loudspeaker (6) into direction of the keyboard (7), this vibrational transfer member (2) comprising: a front transverse zone (20), with reference to the user in a playing situation, intended to receive the keyboard (7), and a transverse zone rear (40) in which is received at least one loudspeaker (6), said respectively front (20) and rear (40) zones being mutually connected so that at least part of the vibrations generated by the loudspeaker ( 6), at the rear area (40), are transmitted in the direction of u keypad (7) located in the front zone (20). 2. Electronic piano according to the preceding claim, wherein the vibrational transfer member is separate from the housing. 3. Electronic piano according to the preceding claim, wherein the transfer member and the housing are made of different materials. 4. Electronic piano according to one of the preceding claims, wherein the vibrational transfer member is metallic. 5. Electronic piano according to one of the preceding claims, wherein the vibrational transfer member comprises a profile, in particular metallic, this vibrational transfer member being in particular formed by said profile. 6. Electronic piano according to the preceding claim, wherein said section is produced by extrusion. 7. Electronic piano according to one of the preceding claims, in which means are provided for fixing this transfer member on the housing. 8. Electronic piano according to one of the preceding claims, wherein the rear transverse area, in which the loudspeaker is received, is open upwards (so that the loudspeaker can diffuse the sound upwards). 9. Electronic piano according to one of the preceding claims, wherein the transverse zones respectively front (20) and rear (40) are made in one piece, in the transverse direction (YY) of the vibrational transfer member ( 2). 10. Electronic piano according to any one of the preceding claims, in which the front (20) and rear (40) zones respectively belong to the front and rear parts respectively of the vibrational transfer member (2), and it is provided fixing means between these parts, these fixing means making it possible to ensure vibrational continuity between said front (20) and rear (40) parts. 11. Electronic piano according to one of the preceding claims, wherein the rear zone of said vibrational transfer member comprises a rear chamber (42) which can be open upwards and / or laterally, and which can present in particular a U-shaped cross section. 12. Electronic piano according to one of the preceding claims, characterized in that said at least one loudspeaker (6) received in said vibrational transfer member (2) is integrated in a sealed loudspeaker enclosure. 13. Electronic piano according to the preceding claim, characterized in that said sealed speaker enclosure (6) is undersized in terms of air volume. 14. Electronic piano according to the preceding claim, wherein said loudspeaker enclosure has a total surge coefficient of at least 1.1, preferably at least 0.90 and which is more preferably between 1.1 and 1, 5. 15. Electronic piano according to one of the preceding claims, further comprising means for securing the keyboard (7) on the front area. 16. Electronic piano according to one of the preceding claims, wherein the front transverse zone comprises a range (22) of support for the keyboard (7). 17. An electronic piano according to the preceding claim, wherein the keyboard support range extends over a major portion of said front transverse area. 18. Electronic piano according to the preceding claim, wherein there is provided an intermediate mounting plate (72), fixed on said pad, the keyboard (7) being secured to this intermediate plate (72). 19. Electronic piano according to one of the preceding claims, characterized in that it is foldable. 20. Electronic piano according to one of the preceding claims, wherein the vibrational transfer member (2) is formed of at least two sections, in its longitudinal direction, two adjacent sections being mutually connected by a mechanical connection means. mobile, removable or foldable, in particular by at least one hinge. 21. Electronic piano according to one of the preceding claims, wherein the vibrational transfer member (2) is formed of three sections, in its longitudinal direction, namely a central section, a right section and a left section, two adjacent sections being mutually connected by a mechanical connecting means in a movable, removable or foldable manner, in particular by at least one hinge. 22. Electronic piano according to the preceding claim, wherein the right section and the left section each comprise a loudspeaker. 23. Electronic piano according to one of the preceding claims, wherein the vibrational transfer member (2), or each section of said vibrational transfer member (2), is closed laterally by at least one flange (100). 24. Electronic piano according to claim 23 dependent on claim 21, wherein in the unfolded state of the piano, the right flange of the central section is in mechanical contact with the left flange of the section. right, and in which the left flange of the central section is in mechanical contact with the right flange of the left section. 25. Electronic piano according to one of the preceding claims, further comprising a base (9), as well as at least one additional speaker (91, 93), mounted on this base (9). 26. Electronic piano according to the preceding claim, characterized in that it comprises a single additional loudspeaker, mounted on an internal surface on one side of said base (9), the internal surface opposite to said loudspeaker having a flat surface, so that the sound waves emitted by the membrane of said loudspeaker can be returned by said flat surface. 27. Electronic piano according to any one of the preceding claims, characterized in that said box (1) is formed of at least one covering element which is in contact with a wall of said rear chamber (42).