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: An assembly for mounting an ultrasound transmitter is provided. The assembly comprises an assembly body having a proximal end, a distal end and perimeters which are perpendicular to a longitudinal axis of the assembly body. The assembly body includes a proximal mount section with a proximal outer perimeter and a proximal inner perimeter which is smaller than the proximal outer perimeter. The assembly body also includes a distal mount section with a distal outer perimeter and a distal inner perimeter which is smaller than the distal outer perimeter. A loop shaped ultrasound transducer abuts the proximal mount section and the distal mount section.

Abstract: Vibration is sensed as a signal by a vibration sensor and the signal level of the sensed signal is measured by an A/D converter. The distance between a position entered by a vibrating input pen and the vibration sensor is calculated and, on the basis of the calculated distance, input level information is obtained from the measured signal level by an arithmetic and control unit.

Abstract: An object of the present invention is to make it possible to input coordinate information continuously among a plurality of input faces in inputting such coordinate information from the plurality of input faces by specifying coordinate positions. When a time measured between an end of a first input on the first input face and a start of a second input on the second input face is within a predetermined time, the first and second inputs are recognized as one continuous input even if the first input is stopped. Furthermore, when the end position of the first input is within a predetermined region, the first and second inputs are recognized as one continuous input even if the first input is stopped. Accordingly, it becomes possible to make a series of inputs by using the plurality of input faces.

Abstract: A method and apparatus for transcribing composite images. In one embodiment, a method comprises projecting a first image onto a surface, wherein a first coordinate system defines positions within the first image and a second coordinate system defines positions on the surface. The method further comprises forming a second image on the surface by using a stylus, and recording the formation of the second image relative to the first image by periodically detecting the position of the stylus relative to the second coordinate system by receiving and processing signals transmitted from the stylus. The method also comprises translating the position of the stylus relative to the second coordinate system to a position relative to the first coordinate system, and storing the composite image comprising the first image and the second image as machine-readable data.

Abstract: In a transcription system which includes a plurality of signal receivers for positioning adjacent a writing surface and for receiving a position signal transmitted from a stylus when the stylus is positioned adjacent the writing surface, the signal receivers producing timing signals in response to receiving the position signal from the stylus, the transcription system using the timing signals to determine a position of the stylus adjacent the writing surface, a detector assembly comprising: a housing for mounting to the writing surface; a plurality of signal receivers; and at least one user activated control switch whose activation by a user when the detector assembly is mounted to the writing surface produces a control signal which causes the transcription system to perform a function in response.

Abstract: A pen positioning system is provided, in which a pen, having multiple output elements, is adapted to accurately determine the location of the pointing tip of the pen, in relation to an electronic tablet. The output elements, preferably ultrasonic transmitters having distinct frequencies, are located a fixed distance from each other, and are also related in space to the pointing tip of the pen. The geometric relationship between the output elements and the pointing tip of the pen allows the location of the pointing tip to be determined, independent of the angle which the pen is inclined against the surface of the writing tablet. A detection system is used to receive the output signals from the output elements, isolate the output signals from each other, and process them independently to determine the location of the output elements and of the pointing tip of the pen.