Harman Audio Electronic Systems Gmbh

Harman Electronic Systems Gmbh

Hans-J&uuml;rgen Regl

Gerhard Krump

Wolfgang Bachmann

The invention relates to the embodiment of so-called panel loudspeakers working according to the bending wave principle. Said panels are generally formed by a panel ( ), at least one driver ( ) and a frame ( ), the panel ( ) being connected to the frame ( ). In order to achieve appropriate bending wave induction in the panel ( ), very complicated assessments must be made in order to determine the corresponding positioning areas ( ) in which the driver ( ) excites the panel ( ) or is connected to the latter. Furthermore, the size of the panels ( ) can change considerably depending on the application so that assessments must only be made repeatedly in the case of panels that can be easily modified. The invention aims at providing general positioning areas ( ) for the driver ( ) in or on the panels ( ) so that no further assessments need to be carried out regarding the positioning area ( ). To this end, an edge area ( ) attached directly to the edges ( ) of the panel ( ) and a center of gravity area ( ) extending along the center of gravity (S) of the panel ( ) are discarded from the very beginning as positioning area ( ). Specifications with respect to the width or enlargement of the different zones ( ) in relation to the dimension of the panel ( ) are also given.

Panel loudspeakers

The invention concerns the embodiment of panel loudspeakers working according to the bending wave principle. Said loudspeakers are generally formed by at least one acoustic panel ( ) and at least one driver ( ), the driver ( ) being connected to the acoustic panel ( ). When such acoustic panels ( ) are used for reproducing low frequency audio signals, the acoustic panel ( ) must be arranged in sufficiently large sound walls in order to exclude the occurrence of an acoustic short circuit between the front part and the back part of the panel. Apart from being costly, only one side of the sound walls is actively used for sound generation as a result of the separation of both acoustic panels ( ). Hence, the invention aims at providing a panel loudspeaker ( ) that does not require any additional sound walls in order to exclude the occurrence of an acoustic short circuit while at the same time enabling full utilization of the surface of the acoustic panel ( ) for sound generation. This is achieved by arranging two of the acoustic panels ( ) at a distance (A) in relation to each other, by providing elements ( ) connecting both acoustic panels ( ) and by arranging the drivers ( ) on the sides of the acoustic panels ( ) facing each other. Due to the fact that, once connected, both acoustic panels ( ) vibrate in opposite directions they mimic the principle of a breathing sphere or wall.

Sound reproduction device working according to the bending wave principle

The invention proposes a contact connection for sound reproduction devices according to the flexural wave principle. Since the drive systems of such installations require high current intensities and such current intensities could only be properly transmitted by massive contact connections which however hinder the flexural wave propagation, the object of the invention is to propose a contact connection which eliminates the problems of the state of the art, and which is also very easy to implement. To that end it is proposed that at least one of the two cover layers and/or the core layer contain conductive areas which are connected to the lines of a sound signal source. It is particularly advantageous if the conductive areas can be manufactured together with the components that are also used to manufacture the core layer

Contact connections

The invention relates to the embodiment of panel loudspeakers working according to the bending wave principle. Such loudspeakers generally consist of an acoustic panel and drivers whereby the drivers are connected to the acoustic panel For the formation of bending waves in the acoustic panel it is essentially important that the drivers do not unnecessarily rigidize the acoustic panel This has led to the arrangement of the drivers at a distance from the acoustic panel in a separate frame. In view of the complexity of such an arrangement, the invention aims at providing a connection between the drivers and the acoustic panel that can be supported directly on the acoustic panel and which does not impede the propagation of the bending waves. This is achieved by connecting the drivers to the acoustic panel only at very few points or by providing elastic member in the fixing area of the drivers. A combination of both embodiments is also described.

Device for dynamic excitation of panel loudspeakers

A projection screen, having a projection surface formed of at least two segments, of which at least two segments are sound radiating segments capable of radiating sound waves from the projection surface and designed to reproduce different frequency ranges.

Projection screen

The invention concerns the embodiment of drivers for panel loudspeakers. Panel loudspeakers working according to the principle of bending waves are already known in prior art. Said loudspeakers generally consist of an acoustic panel ( ) and at least one driver ( ). As a general rule, the driver ( ) is arranged on an auxiliary frame at a distance from the acoustic panel ( ). Said embodiment makes it possible to use conventional drivers ( ) that can also be utilized in cone loudspeakers. A series of problem arise when the drivers ( ) are to be integrated on or into the acoustic panel ( ) itself. Said embodiment requires inter alia that the different components of the driver ( ) be directly mounted on the acoustic panel ( ). Hence, the invention aims at providing a driver for panel loudspeakers that can be connected with little complications to the acoustic panel ( ) as a pre-fabricated component. This is achieved by connecting the oscillation coil support ( ) in the air gap ( ) to the permanent magnet ( ) and/or to magnetic return path device using an elastic membrane ( ).

Driver for a flat acoustic panel

The invention presents a sound reproduction device which operates in accordance with the flexural wave principle. Such devices have in common that a panel,is provided in which flexural waves are produced by a drive arrangement,. The drive arrangements,in the state of the art are connected to one of the surfaces of the panel,and are held by a support structure which functions as a countersupport. Such support structures either hinder the propagation of the flexural waves along the surface of the panel,and/or lead to an increase in the constructed depth of such a sound reproduction device. To avoid these disadvantages of the state of the art, the drive system,is located in a cutout,of the panel,. This not only has the additional advantage that the appearance of both surfaces of the panel,can be standardized, but also that by weakening the panel,in the area of cutout,, the output for the production of flexural waves is reduced, or that the same output can be used to produce the oscillations required for bass sound reproduction.

Growing community of inventors

Wuppertal, Germany

Hans-Jürgen Regl

Growing community of inventors

Wuppertal, Germany

Hans-J&uuml;rgen Regl

Hans-Jürgen Regl