Abstract: A transcription module having a mounting unit, acoustical receivers and an EM detector is disclosed. The mounting unit is adapted for positioning the transcription module over a work surface. First and second acoustical receivers are attached to the mounting unit. Each acoustical receiver includes a microphone positioned over a corresponding location on the work surface. Each microphone views the work surface at the corresponding location and is configured to receive acoustical signals from an input device operating over the work surface at another location. The EM detector detects an EM signal that is synchronized with the acoustical signals.

Abstract: A stylus that includes a tip portion that has a cavity. The cavity has a plurality of holes at a first end and a transmitter of acoustic, e.g., ultrasound waves at the end longitudinally opposite the first end. The tip portion has a tip. The tip end is less than a quarter of a wavelength from the exit ends of the holes. When the end of the tip is placed against a working surface, the acoustic waves travel from the transmitter through the cavity, exit the holes and travel less than a quarter of a wavelength to the working surface relatively close to the tip.

Abstract: An acoustical receiver for detecting an acoustical signal characterized by a wavelength and a pen transcription system utilizing the same are disclosed. The receiver includes a detector that generates an electrical signal in response to acoustical signals in a predetermined frequency range including that wavelength, a housing surrounding the detector, and a receiving horn. The housing has a housing aperture having a maximum dimension less than the acoustical signal wavelength. The receiving horn has a first opening that is adjacent to the housing aperture and a second aperture having a dimension that is greater than the acoustical signal wavelength.

Abstract: A mobile device providing a mobile processing function such as a mobile telephone and/or a personal digital assistant. The mobile device includes a mobile device body, a processing system within the body, the processing system programmed to be part of providing the mobile processing function, a projector coupled to the body to project an image onto a substantially planar surface when the mobile device body is on the surface at a predetermined angle relative to the surface, and a pen-location transcription system coupled to the processing system to record the positions of a writing implement at a plurality of instants of time by transmitting energy between the writing implement and a device mechanically coupled to the mobile device body. In one version, the device mechanically coupled to the mobile device body is a sensor array including at least two sensors of the transmitted energy. The writing implement includes a transmitter of the transmitted energy.

Abstract: An apparatus for operation with or in a projector or a flat panel display, the apparatus including a part board having an associated surface or a frame for a surface, such as a whiteboard, that is pre-assembled to include components that when connected to an external module convert the surface to an electronic transcription apparatus. In one version, the components include a set of sensors and electronics therefor, with wiring and a connector.

Abstract: A pen transcription system and method for locating a moveable signal source are disclosed. The transcription system includes a base having a planar base surface, first and second acoustical sensors that detect an acoustical signal emitted by a moveable signal source, the acoustical sensors being mounted on the base and separated from one another. The difference in time of detection between an EM signal and the acoustical signals is measured to determine the position of the moveable source. The acoustical sensors include a housing surrounding a detector. The housing has an aperture having a width that is less than the wavelength of said acoustical signal divided by 6.28 and a height that is substantially equal to an integer multiple of a wavelength of an interfering acoustical signal.

Abstract: A pen transcription system and method for using the same are disclosed. The pen transcription system includes a receiver having first and second acoustical sensors mounted on a planar base and separated from one another, an EM detector, and a controller. The first and second acoustical sensors detect an acoustical signal emitted by a moveable signal source. The EM detector detects an EM signal that is synchronized with the acoustical signal. The controller measures the difference in time of detection between the EM signal and the acoustical signals detected by the first and second acoustical sensors. The acoustical sensors include a detector and a housing surrounding the detector, the housing having an aperture defined by an axis. The acoustical sensor has a reception function that is symmetrical about the axis and the axis is substantially perpendicular to the base surface.

Abstract: An apparatus and a method for determining the location of a pointing device in the vicinity of a set of receivers able to receive one or more locating signals transmitted through a medium. The method includes receiving at a receiver a signal that includes a locating signal and an interfering signal, determining an estimated interference signal indicative of the interfering signal included in the signal received, determining a signal indicative of the difference between the received signal and the estimated interference signal, and using the signal indicative of the difference to compute the location of the pointing device on a surface near the set of receivers. One version uses a separate receiver from which to determine the estimated interference signal, while another version uses the received signal at a time when there is expected to be no locating signal present in order to determine the estimated interference signal. An adaptive filter computes the estimated interference signal.

Abstract: An apparatus including a part board having an associated surface or a frame for a surface, such as a whiteboard, that is pre-assembled to include components that when connected to an external module convert the surface to an electronic transcription apparatus. In one version, the components include a set of sensors and electronics therefor, with wiring and a connector.

Abstract: A pen transcription system and method for using the same are disclosed. The pen transcription system includes a receiver having first and second acoustical sensors mounted on a planar base and separated from one another, an EM detector, and a controller. The first and second acoustical sensors detect an acoustical signal at a first wavelength emitted by a moveable signal source. The EM detector detects an EM signal that is synchronized with the acoustical signal. The controller measures the difference in time of detection between the EM signal and the acoustical signals detected by the first and second acoustical sensors. The acoustical sensors include a detector and a housing surrounding the detector, the housing having an aperture having a maximum dimension that is less than the first wavelength divided by 6.28.

Abstract: An apparatus and a method for determining the location of a pointing device in the vicinity of a set of receivers able to receive one or more locating signals transmitted through a medium. The method includes receiving at a receiver a signal that includes a locating signal and an interfering signal, determining an estimated interference signal indicative of the interfering signal included in the signal received, determining a signal indicative of the difference between the received signal and the estimated interference signal, and using the signal indicative of the difference to compute the location of the pointing device on a surface near the set of receivers. One version uses a separate receiver from which to determine the estimated interference signal, while another version uses the received signal at a time when there is expected to be no locating signal present in order to determine the estimated interference signal. An adaptive filter computes the estimated interference signal.

Abstract: A portable transmitter having no power consumption while inactive, and a nearly simultaneous indicator of the cause of a transition when power is provided. A transmitter pen in a locator system, having more than one sensor, each separately triggerable, and indicating which sensor was triggered. An on-off circuit coupled to a 1.5 volt battery power source, to a power regulator and multiple sensors, so the regulator consumes no power while inactive. The on-off circuit consumes no power while inactive. When one of the sensors is triggered, the on-off circuit activates, while indicating which sensor was triggered. The circuit has an ON state, in which the regulator and operational circuits operate normally, an IDLE state, in which the circuit consumes little power in anticipation of being activated, and a SHUT-DOWN state, in which the circuit consumes little power in anticipation of a sensor being released.

Abstract: An apparatus including a writing surface, such as a whiteboard, is configured to accept various elements of an electronic transcription system. In one embodiment of the invention, a writing surface, such as a whiteboard or other writing surface, includes an aperture adapted to accept a transducer of the transcription system.

Abstract: A presentation board digitizer system for large boards preferably employs at least three spaced-apart ultrasound receivers assemblies. A current position of an ultrasound transmitter is assigned as a weighted centroid of time-of-flight position measurements based on at least two pairs of receiver assemblies. The weighting used varies as a function of the position of the transmitter across the board. A preferred structure of an ultrasound receiver assembly for use in the system employs a pair of ultrasound receivers arranged side-by-side in a line perpendicular to the surface of the presentation board. The receivers are connected so as to generate a total output signal corresponding to the instantaneous sum of the ultrasound signals received at each, such that the receiver assembly is most sensitive to ultrasound signals incident from a plane adjacent to the presentation board.

Abstract: A presentation board digitizer system for large boards preferably employs at least three spaced-apart ultrasound receivers assemblies. A current position of an ultrasound transmitter is assigned as a weighted centroid of time-of-flight position measurements based on at least two pairs of receiver assemblies. The weighting used varies as a function of the position of the transmitter across the board. A preferred structure of an ultrasound receiver assembly for use in the system employs a pair of ultrasound receivers arranged side-by-side in a line perpendicular to the surface of the presentation board. The receivers are connected so as to generate a total output signal corresponding to the instantaneous sum of the ultrasound signals received at each, such that the receiver assembly is most sensitive to ultrasound signals incident from a plane adjacent to the presentation board.

Abstract: Methods and apparatus for using ultrasound to measure speed and acceleration in fluids is provided. Three exemplary embodiments are disclosed. The first exemplary embodiment measures fluid velocity, such as, for example, wind, under standard atmospheric pressure-temperature. The second exemplary embodiment measures gas velocity, such as, for example, wind, affected by and automatically calibrates for pressure-temperature. The third exemplary embodiment measures gas density, such as, for example, density altitude. Applications of the invention include wind direction and speed calculation in agriculture, aviation, hydraulics, and other industries. One of the advantages provided by the invention is there are no moving parts in making such measurements.

Abstract: A piezoelectric transducer is provided, in which a piezoelectric shell has conductive layers on the outside and inside of the shell, which are adapted to be connected to a signal input source. When the conductive layers are activated, the piezoelectric layer resonates to produce an output signal waveform from the shell structure. An alternative embodiment includes a flat piezoelectric layer with opposing conductive layers, which is then formed into a shell structure. In preferred embodiments, an inner spool is located within the shell structure, which acts to increase the output sound pressure level for the transducer. To increase the sound pressure level further, the inner spool preferably includes a recessed area, which defines a void between the inner conductive layer on the shell and the recessed area. The void acts to increase the characteristic output sound pressure level for the transducer.