Abstract: An apparatus for use as an output device of a user interface to an information processing system includes at least one device for generating a synthetic jet. The device is capable of producing outputs with different modalities. Examples of different modalities that are possible include airflows, vibration and sound.

Abstract: An audio driver including a diaphragm with a first side and a second side. The diaphragm is coupled to a transducer element on the second side and is arranged to radiate sound. The transducer element converts an electrical input signal into movement of the diaphragm. The diaphragm is arranged such that a part of the diaphragm at least partly forms a cavity at the second side of an air conduit is coupled to the cavity. The air conduit has a first opening into the cavity and a second opening outside of the cavity. The air conduit and cavity form a resonator which has a resonance frequency that is less than half a free air acoustic resonance frequency of the audio driver.

Abstract: A cooling device (1) using pulsating fluid for cooling of an object, comprising: a transducer (2) having a membrane adapted to generate pressure waves at a working frequency (fw), and a cavity (4) enclosing a first side of the membrane. The cavity (4) has at least one opening (5) adapted to emit a pulsating net output fluid flow towards the object, wherein the opening (5) is in communication with a second side of the membrane. The cavity (4) is sufficiently small to prevent fluid in the cavity (4) from acting as a spring in a resonating mass-spring system in the working range. This is advantageous as a volume velocity (u1) at the opening is essentially equal to a volume velocity (u1?) at the second side of the membrane, apart from a minus sign. Thus, at the working frequency the pulsating net output fluid can be largely cancelled due to the counter phase with the pressure waves on the second side of the membrane resulting in a close to zero far-field volume velocity.

Abstract: An audio driver comprising a diaphragm (101, 103) with a first side and a second side. The diaphragm (101, 103) is coupled to a transducer element (109, 111) on the second side and is arranged to radiate sound. The transducer element (109, 111) converts an electrical input signal into movement of the diaphragm (101, 103). The diaphragm (101, 103) is arranged such that a part of the diaphragm (103) at least partly forms a cavity (113) at the second side and an air conduit (115) is coupled to the cavity (113). The air conduit (115) has a first opening (117) into the cavity and a second opening (119) outside the cavity (113). The air conduit (115) and cavity (113) form a resonator which has a resonance frequency that is less than half a free air acoustic resonance frequency of the audio driver. The invention may allow simultaneous sound production and an acoustic air flow generation while maintaining an efficient decoupling between the two functionalities.

Abstract: An alert device and method include an elongated cavity (306) and a loudspeaker (302) coupled to a first end portion of the cavity wherein sound produced by the loudspeaker is directed through the cavity to provide an audible sound. The cavity and the loudspeaker are configured and dimensioned to provide the audible sound substantially at an anti-resonant frequency (Fb) between first and second resonant frequency peaks for system impedance in a response spectrum for the loudspeaker and the cavity.

Abstract: An apparatus for use as an output device of a user interface to an information processing system includes at least one device (15;20) for generating a synthetic jet flow.

Abstract: A cooling device (1) using pulsating fluid for cooling of an object, comprising: a transducer (2) having a membrane adapted to generate pressure waves at a working frequency (fw), and a cavity (4) enclosing a first side of the membrane. The cavity (4) has at least one opening (5) adapted to emit a pulsating net output fluid flow towards the object, wherein the opening (5) is in communication with a second side of the membrane. The cavity (4) is sufficiently small to prevent fluid in the cavity (4) from acting as a spring in a resonating mass-spring system in the working range. This is advantageous as a volume velocity (u1) at the opening is essentially equal to a volume velocity (u1?) at the second side of the membrane, apart from a minus sign. Thus, at the working frequency the pulsating net output fluid can be largely cancelled due to the counter phase with the pressure waves on the second side of the membrane resulting in a close to zero far-field volume velocity.

Abstract: A device (30) for adapting an audio input signal (V1n) to a transducer unit (20) comprises: mapping means (10) for mapping input signal components from a first audio frequency range onto a second audio frequency range so as to produce a mapped audio signal (VM), wherein the second audio frequency range is narrower than the first audio frequency range, and wherein the transducer unit (20) has a maximum efficiency at the second audio frequency range, filter means (31) for filtering the input signal (V1n) so as to produce a filtered input signal (V1n?) having a third audio frequency range, and combination means (32) for combining the mapped audio signal (VM) and the filtered input signal (V1n?) so as to produce a transducer signal (VT). The first audio frequency range is preferably contained in the second audio frequency range, while the third audio frequency range may be adjacent the first audio frequency range.

Abstract: An illumination device (1) comprising: at least one light emitting device (5); and a suspension structure (2), suspending the at least one light emitting device (5) in a desired position. Further, the illumination device (1) has a transducer (6), adapted to generate pressure waves at a drive frequency; wherein the suspension structure (2) is utilized as a flow guiding structure (7), having a first end adapted to receive the pressure waves from the transducer, and a second end adapted to generate a pulsating net output flow towards the at least one light emitting device (5), thereby cooling the at least one light emitting device (5). By utilizing the suspension structure itself as flow guiding structure cooling can be integrated in a cost efficient way. Further, no additional space is required to accommodate the flow guiding structure.

Abstract: A cooling device comprising at least one transducer (1) having a membrane adapted to generate pressure waves at a working frequency, characterized by a first and a second cavity (3, 4), said transducer being arranged between said first and second cavities, such that said membrane forms an fluid tight seal between said cavities, each cavity having at least one opening (7, 8) adapted to emit a pulsating net output fluid flow, wherein said cavities and openings are formed such that, at said working frequency, a first harmonic fluid flow emitted by said opening(s) (7) of a first one of said cavities is in anti-phase with a second harmonic fluid flow emitted by said opening(s) (8) of a second one of said cavities, so that a sum of harmonic fluid flow from said openings is essentially zero. With this design, sound reproduction at the working frequency is largely cancelled due to the counter phase of the outlets resulting in a close to zero far-field volume velocity.

Abstract: A device is arranged for driving a transducer unit (20) comprising at least one transducer (21) accommodated in an enclosure (22). The device comprises mapping means for mapping input signal components having a first audio frequency range onto a second audio frequency range. The second audio frequency range is narrower than the first audio frequency range, and the second frequency range contains the Helmholtz frequency of the transducer unit (20). A transducer unit (20) for use with the device is optimized for operating in a narrow frequency range at or near the Helmholtz frequency (fH).

Abstract: A loudspeaker protection system includes a filter arrangement for defining one or more frequency bands of an audio signal, controllable amplifier/attenuator combinations coupled to the filter arrangement, and a processing arrangement coupled to control the amplifier/attenuator combinations, such as to determine audio power in at least one of the frequency bands representing relevant loudspeaker protection information used for selective audio power control in the at least one frequency band. This system has the features for a fast and/or slow thermal protection, as well as for a cone excursion protection, all for a loudspeaker in such a system.

Abstract: A color television display tube comprising at least eight correction coils, arranged in one plane about the tube neck, for controlling the static convergence and possibly other aspects such as color purity.