Abstract: A wearable portable entertainment and personal communication system which provides high quality sound, particularly at low audio frequencies, and which does not block or attenuate environmental sounds is disclosed. In a first embodiment, a transducer or transducer array is positioned on a wall in a sampling chamber between two cavities. One of the cavities is sealed and the other has one or more conduit members which direct the acoustic signals to one or both of the wearer's ears. In a second embodiment, both cavities have conduits, one directed to each of the wearer's ears. With either embodiment, the sampling chamber optionally can be combined with separate high frequency transducers. With both embodiments, the chambers are incorporated into a wearable garment and the transducers are connected to a source of audio signals.

Abstract: A wearable portable entertainment and personal communication system which provides high quality sound, particularly at low audio frequencies, and which does not block or attenuate environmental sounds is disclosed. In a first embodiment, a transducer or transducer array is positioned on a wall in a sampling chamber between two cavities. One of the cavities is sealed and the other has one or more conduit members which direct the acoustic signals to one or both of the wearer's ears. In a second embodiment, both cavities have conduits, one directed to each of the wearer's ears. With either embodiment, the sampling chamber optionally can be combined with separate high frequency transducers. With both embodiments, the chambers are incorporated into a wearable garment and the transducers are connected to a source of audio signals.

Abstract: A device with a speaker system and adapted to wear on the head of a wearer, such as a headband, is provided. Transducers are situated in a wearable device and positioned on opposite sides of the wearer's head, adjacent the ears. In one embodiment, the transducers share a common enclosure and are driven 180.degree. out of phase, so that back pressures cancel and low frequency response is enhanced. In another embodiment, two vented enclosures are provided, each with its own transducers. In other embodiments, acoustic concentrators can be incorporated to direct the audio more directly toward the wearer's ears. The speaker system is connected to or in communication with a conventional source of audio signals, such as a radio, tape player, CD player, cellular telephone or the like.

Abstract: An audio interface garment includes systems for attenuating the influence of sound waves generated by audio output devices on output signals from a plurality of input devices an. In one embodiment, input signals which are applied to the audio output devices are combined by a mixer to form a mixed audio signal. A plurality of Widrow-Hoff least mean square adaptive filters each form a corresponding filtered signal based upon the mixed audio signal and the output signal from a corresponding one of the input devices. A plurality of processed signals are formed by differencing each filtered signal from the corresponding output signal. The weight values of the adaptive filters are modified according to the least mean square method. The processed signals provide signals in which the first sound waves are attenuated.

Abstract: A personal wearable portable communication and entertainment system which provides improved quality audio response and which does not interfere with the wearer's activities or block environmental sounds is disclosed. Transducers or speakers, which preferably are provided in arrayed pairs, are situated in a wearable structure, such as a garment for the wearer's torso or a headband for the wearer's head. The transducers are positioned on opposite sides of the wearer's torso or head, adjacent the ears. In one embodiment, the transducers share a common closed enclosure and are driven 180.degree. out of phase, so that back pressures cancel. In another embodiment, two hollow enclosures are provided, each with its own transducer and acoustic aperture. In a further embodiment, the transducers are positioned in a common hollow enclosure with at least one acoustic aperture between them.

Abstract: An aligner for aligning a mask and a wafer during photolithography of a semiconductor chip uses detection of the differential capacitance between two sets of conductive fingers on the mask and ridges on the wafer. An A.C. signal is coupled between the ridges and the fingers and the phase or amplitude of the signals is detected. An aligner utilizing multiple groups of ridges and fingers allows rotational alignment or two axis lateral alignment. An aligner having reference ledges to which the mask and the wafer are capacitively coupled allows alignment when the distance between the mask and the wafer is too great to permit meaningful capacitive coupling between the mask and the wafer to occur.

Abstract: A novel structure which reduces stress due to cavitation in a thermal ink jet head is disclosed. A jetting resistor is formed on a thin membrane and suspended in contact with an acoustic absorber such as silicon oil on its back surface. The pressure wave created by the collapsing bubble which occurs in the ink on the membranes front surface each time the resistor is fired is thus absorbed by the silicon oil. The failure rate of such a jetting resistor is thus substantially reduced.

Abstract: A new type of thermal ink jet print head is provided which is driven by an electron beam. The print head is constructed of an electron permeable thin film (electron window) which in one embodiment, has on one of its surfaces a plurality of electron absorbing (heater) pads that are in thermal contact with an ink reservoir. As electrons from a CRT traverse the thin film and are absorbed by a pad, they introduce an extremely large and rapid temperature increase in the pad. As a result, a sufficient amount of thermal energy is absorbed by the ink to cause a vapor explosion within the ink, thereby ejecting ink droplets from a nearby orifice in the ink reservoir. In another embodiment, the electrons traverse the window and are absorbed in the ink rather than in pads, and in another embodiment the electrons are absorbed directly in the window itself.