Patent Description:
<CIT> discloses a loudspeaker comprising a panel adapted to support bending waves and an exciter for exciting said bending waves employs an exciter having an effective size with which it acts on said panel, the effective size varying in dependence on the frequency with which the exciter acts on the panel.

<CIT> discloses an electromechanical force transducer comprising a plurality of resonant elements, a low stiffness member coupled between the adjacent faces of at least two adjacent resonant elements, and a stub member on which the resonant elements are supported and for coupling the transducer to a site to which force is to be applied.

<CIT> discloses an inertial force transducer having an operative frequency range comprises a resonant element having a frequency distribution of modes in the operative frequency range of the transducer and coupling means for mounting the resonant element to a site to which force is to be applied. The resonant element is a piezoelectric device comprising a layer of piezoelectric material and a substrate layer on the layer of piezoelectric material. The substrate layer has a region extending beyond the piezoelectric layer, with the coupling means mounted to the extended region whereby the low frequency performance of the transducer is extended.

<CIT> relates to a piezoelectric element body which has a pair of substantially parallel flat plate electrodes opposed to each other and a piezoelectric body inserted between the pair of flat plate electrodes to convert electricity into mechanical vibration.

According to the invention, there is provided a distributed mode loudspeaker as defined in claim <NUM> and a method as defined in claim <NUM>.

A piezoelectric transducer in a distributed mode loudspeaker may include multiple electrode pairs used to generate sounds at different frequencies. For instance, the piezoelectric transducer may include a layer of a piezoelectric material, e.g., a piezoelectric ceramic material, that extends between each electrode pair. For example, the layer may have a first electrode from an electrode pair on top of the layer and a second electrode from the electrode pair below the layer.

The distributed mode loudspeaker includes a drive module that selectively energizes one or more of the multiple electrode pairs to generate a sound at a particular subset of frequencies within the range of frequencies at which the distributed mode loudspeaker can generate sounds. The drive module may provide current to one or more selected electrode pairs to cause a load, e.g., a display panel, connected to the distributed mode actuator, to generate the sound at the particular subset of frequencies.

Aspects of the present disclosure are defined by the appended claims. In general, we describe methods that include the actions of determining, for a piezoelectric transducer of a distributed mode loudspeaker adapted to create forces to cause vibration of a load to generate sound waves within a range of frequencies, a subset of frequencies, from the range of frequencies, at which to output a sound; selecting, based on the subset of frequencies, one or more electrode pairs from two or more electrode pairs included in the piezoelectric transducer to generate the sound, each electrode pair including a first electrode on a first side of a layer included in the piezoelectric transducer and a second electrode on a second side of the layer opposite the first side, and connected to a different portion of the layer; and providing, by a drive module connected to each of the two or more electrode pairs, current to each of the selected one or more electrode pairs to cause the piezoelectric transducer to generate a force that, when provided to a load, causes the load to generate the sound within the subset of frequencies. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods. A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

We also describe a system that includes a distributed mode loudspeaker including: a piezoelectric transducer: that includes two or more electrode pairs each of which a) include a first electrode on a first side of a layer included in the piezoelectric transducer, b) include a second electrode on a second side of the layer opposite the first side, and c) are connected to a different portion of the layer; and is adapted to create forces to cause vibration of a load to generate sound waves within a range of frequencies; a controller configured to: determine, for the piezoelectric transducer, a subset of frequencies, from the range of frequencies, at which to output a sound; and select, based on the subset of frequencies, one or more electrode pairs from the two or more electrode pairs included in the piezoelectric transducer to generate the sound; and a drive module: connected to each of the two or more electrode pairs and adapted to provide current to at least some of the two or more electrode pairs to cause the piezoelectric transducer to generate a force that, when provided to the load, causes the load to generate a sound; and configured to provide current to each of the selected one or more electrode pairs to cause the piezoelectric transducer to generate a force that, when provided to the load, causes the load to generate the sound within the subset of frequencies. Other embodiments of this aspect include corresponding computer systems, methods, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the operations. The computer system may include one or more computers and can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

We also describe an apparatus that includes a smartphone including: a display configured to present content; a piezoelectric transducer: that includes two or more electrode pairs each of which a) include a first electrode on a first side of a layer included in the piezoelectric transducer, b) include a second electrode on a second side of the layer opposite the first side, and c) are connected to a different portion of the layer; and is adapted to create forces to cause vibration of a load to generate sound waves within a range of frequencies; a controller configured to: determine, for the piezoelectric transducer, a subset of frequencies, from the range of frequencies, at which to output a sound; and select, based on the subset of frequencies, one or more electrode pairs from the two or more electrode pairs included in the piezoelectric transducer to generate the sound; and a drive module: connected to each of the two or more electrode pairs and adapted to provide current to at least some of the two or more electrode pairs to cause the piezoelectric transducer to generate a force that, when provided to the load, causes the load to generate a sound; and configured to provide current to each of the selected one or more electrode pairs to cause the piezoelectric transducer to generate a force that, when provided to the load, causes the load to generate the sound within the subset of frequencies; one or more application processors configured to execute an application for the smartphone; and one or more memories one which are stored instructions that are operable, when executed by the one or more application processors, to cause the one or more application processors to execute the application. Other embodiments of this aspect include corresponding computer systems, methods, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the operations. The computer system may include one or more computers and can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. Selecting, based on the subset of frequencies, the one or more electrode pairs from the two or more electrode pairs included in the piezoelectric transducer to generate the sound may include selecting, based on the subset of frequencies, a subset of electrode pairs from the two or more electrode pairs. Determining the subset of frequencies, from the range of frequencies, at which to output the sound may include determining a high frequency range subset, from the range of frequencies, at which to output the sound. Selecting, based on the subset of frequencies, a subset of electrode pairs from the two or more electrode pairs may include selecting, based on the determined high frequency range subset, one electrode pair from the two or more electrode pairs. Selecting, based on the determined high frequency range subset, one electrode pair from the two or more electrode pairs may include selecting, based on the determined high frequency range subset, a particular electrode pair that is closest to a support a) fixedly connected to the piezoelectric transducer, b) connected to the load, and c) that transfers the force from the piezoelectric transducer to the load. The method may include determining a medium frequency range subset, from the range of frequencies, at which to output a second sound that is a different sound than the sound; selecting, based on the determined medium frequency range subset, two or more particular electrode pairs from three or more electrode pairs included in the piezoelectric transducer, the three or more electrode pairs including the two or more electrode pairs; and providing, by the drive module that is connected to each of the three or more electrode pairs, current to each of the selected two or more electrode pairs to cause the piezoelectric transducer to provide a force to the load and the load to generate the second sound within the medium frequency range subset.

In some implementations, selecting, based on the subset of frequencies, the one or more electrode pairs from the two or more electrode pairs included in the piezoelectric transducer to generate the sound may include selecting, based on the subset of frequencies, all of the two or more electrode pairs. Determining the subset of frequencies, from the range of frequencies, at which to output the sound may include determining a low frequency range subset, from the range of frequencies, at which to output the sound. Selecting, based on the subset of frequencies, all of the two or more electrode pairs may include selecting, based on the determined low frequency range subset, all of the two or more electrode pairs.

In some implementations, the system includes the load. The system may include a smartphone. The load may be a display of the smartphone, e.g., configured to present content. The display may present content to a user operating the smartphone. The distributed mode loudspeaker may include a support fixedly connected to the piezoelectric transducer that, when connected to the load, transfers at least some of the force generated by the piezoelectric transducer to the load. At least some electrode pairs from the two or more electrode pairs may share a common ground, have a separate ground. Some of the electrode pairs may share a common ground and some of the electrode pairs may have separate grounds. Each electrode pair from the two or more electrode pairs may have a separate ground. The layer may be ceramic.

Among other advantages, the systems and methods described below may reduce distributed mode loudspeaker power usage, increase impedance in distributed mode loudspeakers, reduce capacitance in distributed mode loudspeakers, or a combination of two or more of these.

<FIG> show an example device <NUM> that includes a distributed mode loudspeaker <NUM>. The device <NUM>, such as a smartphone or another type of computer, uses the distributed mode loudspeaker <NUM>, shown in <FIG>, to generate sound. The sound may be any type of sound, such as a phone conversation, music, an audio stream, sound for a video, or sound for a game.

The distributed mode loudspeaker <NUM> includes a panel <NUM> that vibrates and generates sound waves. The panel <NUM> may be any appropriate panel included in the device <NUM> that can generate sound waves. For instance, the panel <NUM> may be a display panel included in the device <NUM>. The display panel may include a touch screen or any other appropriate type of display.

The panel <NUM> is connected to a support <NUM>, shown in <FIG>, that transfers a force from a piezoelectric transducer <NUM> to the panel <NUM>. The panel <NUM> is rigidly connected to the support <NUM> so that the support <NUM> can efficiently transfer force to the panel <NUM>. In some implementations, the panel <NUM> may be removably connected to the support <NUM> during manufacturing of the device <NUM>, e.g., the support <NUM> can be disconnected from the panel <NUM>. In some examples, the panel <NUM> may be fixedly connected to the support <NUM>, e.g., the support <NUM> is intended to be permanently fixed to the panel <NUM> without causing damage to remove the support <NUM> from the panel <NUM>.

In some implementations, another component may be part of the connection between the panel <NUM> and the support <NUM>. For example, the support <NUM> may rigidly connect to a chassis that rigidly connects to the panel <NUM>.

The piezoelectric transducer <NUM> is connected to the support <NUM> to allow transfer of at least some of a force, generated by the piezoelectric transducer <NUM>, from the piezoelectric transducer <NUM>, through the support <NUM>, and into the panel <NUM>. The piezoelectric transducer <NUM> is rigidly connected to the support <NUM> so that the piezoelectric transducer <NUM> can efficiently transfer force to the support <NUM>. In some examples, the piezoelectric transducer <NUM> is fixedly connected to the support <NUM>, e.g., permanently fixed to the support <NUM> such that removal would cause damage to the support <NUM>, the piezoelectric transducer <NUM>, or both. The piezoelectric transducer <NUM> may be removably connected to the support <NUM>, e.g., such that the piezoelectric transducer <NUM> may be disconnected from the support <NUM> without causing damage to either.

The piezoelectric transducer <NUM> generates the force by actuating in response to receipt of a signal from a drive module included in the distributed mode loudspeaker <NUM>. For instance, the piezoelectric transducer <NUM> includes multiple electrode pairs <NUM>-<NUM> each of which is connected to the drive module to allow the corresponding electrode pair <NUM>-<NUM> to receive an activation signal, e.g., current, from the drive module. When an electrode pair <NUM>-<NUM> receives a signal from the drive module, the electrode pair <NUM>-<NUM> produces an electric field across at least a portion of a layer <NUM> of piezoelectric material of the piezoelectric transducer <NUM>. The electric field causes a physical change in dimension of the piezoelectric material, and the associated displacement of the actuator generates a force.

The electrode pairs <NUM>-<NUM> may be connected to the layer <NUM> in any appropriate manner. For instance, the electrode pairs <NUM>-<NUM> may be fixedly connected to the layer <NUM> during manufacturing, e.g., through a deposition and patterning process. The electrode pairs <NUM>-<NUM> may include separate grounds. For example, the electrodes 110a, 112a, and 114a may be positive electrodes each of which has a corresponding ground electrode 110b, 112b, and 114b, respectively. The piezoelectric transducer <NUM> may include any appropriate combination of positive electrodes and ground electrodes. For instance, the electrodes 110a, 112b, and 114b may be positive electrodes while the other electrodes 110b, 112a, and 114a are ground electrodes. In some examples, the electrode pairs <NUM>-<NUM> may include a common ground. For example, the electrodes 110a, 112a, and 114a may be positive electrodes and the electrodes 110b, 112b, and 114b may be a single common ground electrode.

The layer <NUM> may be any appropriate type of piezoelectric material. For instance, the layer <NUM> may be a ceramic or crystalline piezoelectric material. Examples of ceramic piezoelectric materials include barium titanate, lead zirconium titanate, bismuth ferrite, and sodium niobate, for example. Examples of crystalline piezoelectric materials include topaz, lead titanate, lithium niobate, and lithium tantalite.

The actuation of the layer <NUM> by the electrode pairs <NUM>-<NUM> may be movement of a portion of the layer <NUM> in a vertical direction <NUM> perpendicular to a large surface of the layer <NUM>. Different portions of the layer <NUM> actuate separately depending on the electrode pairs <NUM>-<NUM> that receive a signal from the drive module. For instance, when a first electrode pair 110a-b receives a signal from the drive module, the first electrode pair 110a-b may primarily cause a portion of the layer <NUM> that is closest to the support <NUM>, and connected to the first electrode pair 110a-b, to actuate. When a second electrode pair 112a-b receives a signal from the drive module, the second electrode pair 112a-b may primarily cause a middle portion of the layer <NUM>, connected to the second electrode pair 112a-b, to actuate. When a third electrode pair 114a-b receives a signal from the drive module, the third electrode pair 114a-b may primarily cause an end portion of the layer <NUM> that is farthest away from the support <NUM>, and connected to the third electrode pair 114a-b, to actuate.

In some implementations, the various electrode pairs <NUM>-<NUM> primarily cause a respective portion of the layer <NUM> to actuate in response to receiving a signal because adjacent portions of the layer <NUM> may also actuate to a lesser degree than the respective portion of the layer <NUM> to which the electrode pair is connected. For example, when the first electrode pair 110a-b receives a signal from the drive module, the first electrode pair 110a-b primarily causes the portion of the layer <NUM> connected to the first electrode pair 110a-b to actuate and generate a force and may also cause some of the portion of the layer <NUM> connected to the second electrode pair 112a-b to actuate.

The distributed mode loudspeaker <NUM> includes multiple electrodes to allow separate selection, energization, or both, of different portions of the layer <NUM>. For instance, the distributed mode loudspeaker <NUM> may selectively energize some of the electrodes for better reproduction of sounds at certain frequencies, to reduce power consumption, or both.

<FIG> show a distributed mode loudspeaker <NUM> separately energizing electrode pairs 202a-c to actuate a transducer layer <NUM> based on an output frequency subset. The distributed mode loudspeaker <NUM> may be an example of the distributed mode loudspeaker <NUM> discussed with reference to <FIG>. The electrode pairs 202a-c may correspond to the electrode pairs <NUM>-<NUM>. The transducer layer <NUM> may correspond to the layer <NUM>. The support <NUM> may correspond to the support <NUM>.

A drive module <NUM>, included in the distributed mode loudspeaker <NUM>, may energize only some of the electrode pairs 202a-c when generating high frequency sounds, as shown in <FIG>. In some examples, the drive module <NUM> may energize a first electrode pair 202a for high frequency sound generation. The first electrode pair <NUM> may be closest to a support to which a piezoelectric transducer, that includes the electrodes 202a-c and the transducer layer <NUM>, is connected. The drive module <NUM> may energize only some of the electrode pairs 202a-c to reduce power consumption when generating sound.

The drive module <NUM> may energize multiple electrode pairs 202a-b to generate medium frequency sounds, as shown in <FIG>. The multiple electrode pairs 202a-b may include two or more electrode pairs. The multiple electrode pairs 202a-b may include fewer than all of the electrode pairs 202a-c included in the distributed mode loudspeaker <NUM>. In some examples, the drive module <NUM> may select and energize adjacent electrode pairs, e.g., two electrode pairs 202a-b closest to the support or two electrode pairs 202b-c furthest from the support <NUM>, to generate a medium frequency sound. In some examples, the drive module <NUM> may select and energize two electrode pairs that are not adjacent to each other, e.g., a first electrode pair 202a and a third electrode pair 202c.

The drive module <NUM> may energize multiple electrode pairs 202a-c to generate low frequency sounds, as shown in <FIG>. The multiple electrode pairs 202a-c may include three or more electrode pairs. For example, the drive module <NUM> may select and energize all of the electrode pairs 202a-c included in the distributed mode loudspeaker <NUM> to generate a low frequency sound. The drive module <NUM> may select multiple electrode pairs 202a-c for more accurate reproduction of low frequency sounds by the distributed mode loudspeaker <NUM>, e.g., to reproduce a wider range of low frequency sounds.

<FIG> is a flow diagram of a process <NUM> for providing current to a subset of two or more electrode pairs included in a piezoelectric transducer. For example, the process <NUM> can be used by the distributed mode loudspeaker <NUM> from the device <NUM>.

A distributed mode loudspeaker receives input identifying a sound to output (<NUM>). For example, a drive module or a controller, included in the distributed mode loudspeaker, may receive a signal that identifies the sound to output. The signal may be any appropriate type of signal for a speaker, a distributed mode loudspeaker, or both. The drive module or the controller may receive the input from an application executing on a device, e.g., a phone or music application on a smartphone. The drive module may be the same component in the distributed mode loudspeaker as the controller. In some examples, the drive module may be a different component than the controller in the distributed mode loudspeaker.

The distributed mode loudspeaker is configured to generate sound waves within a range of frequencies. For example, the manufacturing design of the distributed mode loudspeaker, potentially including configuration parameters for a panel, a support, and a piezoelectric transducer, all of which are included in the distributed mode loudspeaker, may correspond to the range of frequencies at which the distributed mode loudspeaker can generate sounds.

The distributed mode loudspeaker determines a subset of frequencies at which to output the sound (<NUM>). The subset of frequencies is a subset of frequencies from the range of frequencies at which the distributed mode loudspeaker can generate sounds. The subset of frequencies may be a proper subset of the range of frequencies at which the distributed mode loudspeaker can generate sounds. The drive module or the controller may use data from the signal to determine the subset of frequencies. For instance, the drive module or the controller may determine that the signal identifies the subset of frequencies at which to output the sound.

The distributed mode loudspeaker selects, based on the subset of frequencies, one or more electrode pairs from two or more electrode pairs included in a piezoelectric transducer to generate the sound (<NUM>). The drive module or the controller may use any appropriate method to select the one or more electrode pairs based on the subset of frequencies. In some examples, the drive module or the controller may use an algorithm that outputs, for a subset of frequencies, a number of electrode pairs to energize, identifiers for electrode pairs to energize, or both, to generate the sound. For instance, the drive module or the controller may use a mapping of frequency subset ranges, from the range of frequencies, to input values when selecting the one or more electrode pairs from the two or more electrode pairs included in the piezoelectric transducer.

In some examples, when the controller is a different component from the drive module and determines the subset of frequencies, the controller provides data for the subset of frequencies to the drive module. For instance, the controller that determines the subset of frequencies at which to output the sound and provides data for the subset of frequencies to the drive module. The data for the subset of frequencies may be data that identifies the subset of frequencies, e.g., data representing numerical values for the subset of frequencies. In response to receiving the data for the subset of frequencies, the drive module uses the data for the subset of frequencies to select the one or more electrode pairs included in the piezoelectric transducer to generate the sound.

The distributed mode loudspeaker includes the piezoelectric transducer. The distributed mode loudspeaker may include any appropriate number of electrode pairs greater than or equal to two. For example, the distributed mode loudspeaker may include two, three, four, five, six, or nine electrode pairs.

The distributed mode loudspeaker provides, using a drive module, current to each of the selected one or more electrode pairs (<NUM>). For example, the drive module provides the current to the positive electrodes from the selected one or more electrode pairs. When at least some of the electrode pairs share a common ground, the drive module provides input current to the separate positive electrodes, each of which is from one of the electrode pairs, and the distributed mode loudspeaker receives output current from the electrode pairs through the common ground. When the electrode pairs have separate ground electrodes, the distributed mode loudspeaker receives the output current from the separate ground electrodes, from the selected one or more electrode pairs, based on providing input current to the separate positive electrodes from the selected one or more electrode pairs.

The distributed mode loudspeaker generates, with the piezoelectric transducer using the selected one or more electrode pairs, a force that, when provided to a load, causes the load to generate the sound within the subset of frequencies (<NUM>). For instance, receipt of the current by the electrode pairs causes a layer, included in the piezoelectric transducer, to actuate and generate a force. A support, included in the distributed mode loudspeaker, may transfer the force, or at least a portion of the force, from the piezoelectric transducer to a panel. Receipt of the force or the portion of the force by the panel causes the panel to vibrate and generate the sound identified by the input.

In some implementations, the process <NUM> can include additional steps, fewer steps, or some of the steps can be divided into multiple steps. For example, the distributed mode loudspeaker may determine a subset of frequencies at which to output a sound and select one or more electrode pairs to generate the sound without performing the other steps in the process <NUM>. In some examples, the distributed mode loudspeaker may perform steps <NUM>, <NUM>, and <NUM> without performing the other steps in the process <NUM>.

One or more of the steps in the process <NUM> may be performed automatically in response to a prior step in the process <NUM>. For example, the distributed mode loudspeaker may determine the subset of frequencies in response to receiving the input. The distributed mode loudspeaker may select the one or more electrode pairs from the two or more electrode pairs included in the piezoelectric transducer in response to determining the subset of frequencies. The drive module may provide current to each of the selected one or more electrode pairs in response to selecting the one or more electrode pairs. The piezoelectric transducer may generate the force in response to receiving the current from the drive module.

In some implementations, when the distributed mode loudspeaker is included in a smartphone, the smartphone may include a display, e.g., a display panel, one or more processors, and one or more memories. The display may be a load used by the distributed mode loudspeaker to generate sound. In some examples, the smartphone may include a load different from the display for the distributed mode loudspeaker to use when generating a sound.

The memories may store instructions for an application, e.g., from which the distributed mode loudspeaker receives the input identifying the sound to output. The one or more processors, e.g., one or more application processors, may use the instructions stored on the one or more memories to execute the application. During execution of the application, e.g., a phone application or a music application or a game, the application may determine a sound to output to a user. The application provides, to the distributed mode loudspeaker, data for the sound.

The controller or the drive module in the distributed mode loudspeaker receive the data for the sound as input. The controller may be the same component in the smartphone. In some examples, the controller is a different component in the smartphone from the drive module. The controller, the drive module, or a combination of the two, use the data for the sound to determine the subset of frequencies, select the one or more electrode pairs, and provide current to the selected one or more electrode pairs.

In some examples, the one or more processors, the one or more memories, or both, are separate from the drive module, the controller, or both. For example, the controller, the drive module, or both, may include at least one processor, at least one memory, or both. The at least one processor may be a different set of processors from the one or more processors. The at least one memory may be a different memory from the one or more memories.

Embodiments of the subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible non-transitory program carrier for execution by, or to control the operation of, data processing apparatus.

The term "data processing apparatus" refers to data processing hardware and encompasses all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, or multiple processors. The apparatus can optionally include, in addition to hardware, code that creates an execution environment for computer programs, e.g., code that constitutes processor firmware, a protocol stack, an operating system, or a combination of one or more of them.

For example, a distributed mode loudspeaker, e.g., a drive module or a controller or both, may include a data processing apparatus. The distributed mode loudspeaker may use the data processing apparatus, in conjunction with at least one memory, to perform one or more of the operations described in this document.

Computers suitable for the execution of a computer program include, by way of example, general or special purpose microprocessors or both, or any other kind of central processing unit.

A distributed mode loudspeaker may include one or more memories that store instructions which, when executed by the distributed mode loudspeaker, cause the distributed mode loudspeaker to perform one or more operations described in this document. For instance, the instructions may cause the distributed mode loudspeaker to determine an output frequency subset, energize one or more electrodes, or both. In some examples, the drive module or the controller or both may include the one or more memories or some of the one or more memories.

To provide for interaction with a user, embodiments of the subject matter described in this specification can be implemented on a computer having a display device, e.g., an LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer.

Claim 1:
A distributed mode loudspeaker (<NUM>) comprising:
a display panel (<NUM>);
a support (<NUM>) attached to the display panel;
a piezoelectric transducer (<NUM>), the piezoelectric transducer comprising a layer of piezoelectric material (<NUM>), the piezoelectric transducer being rigidly connected to the support at one end and extending parallel to the display panel to a free end opposite the end attached to the support, the piezoelectric transducer further comprising electrode layers arranged on opposing sides of the layer of piezoelectric material, the electrode layers comprising two or more electrode pairs (<NUM>-<NUM>), each electrode pair comprising a first electrode on a first side of the opposing sides and a second electrode on a second side of the opposing sides; and
a drive module (<NUM>) connected to each of the two or more electrode pairs and adapted to selectively provide current to the two or more electrode pairs to generate a force that, when provided to the display panel, causes the display panel to generate sound waves.