Abstract: An apparatus for detecting a plurality of user interactions, comprising: at least one detector for sensing the user interactions, a respective controller, associated with each of the detectors, for finding positions of the user interactions, and a switcher, associated with the controllers, for handling the user interactions, according to a defined policy.

Abstract: A video signal has a visual image (12) and carries data for optical detection (54) via the image. The data for optical detection is encoded (52) as data bits in a plurality of lines within a defined region (14) within the image. A corresponding decoder (16, 58) uses maximal energy methods to detect the defined region prior to decoding the data.

Abstract: A method for noise reduction in a digitizer, the digitizer comprising a plurality of detecting elements for detecting an electromagnetic signal at one of a number of predetermined frequencies: the method comprising: sampling at least two of said detecting elements substantially simultaneously to obtain outputs therefrom, and reducing the output on one of said two elements in accordance with the output on the other of said elements.

Abstract: A detector for detecting touches by fingers or like body parts on a sensor comprises at least one sensing conductor, typically a grid of such conductors, extending into the sensor, a source of oscillating electrical energy at a predetermined frequency, and detection circuitry for detecting a capacitive influence on the sensing conductor when said oscillating electrical energy is applied, the capacitive influence being interpreted as a touch. The detector is advantageous in that the same sensing conductors can be used both for touch sensing and for detection of an electromagnetic stylus.

Abstract: Apparatus for user input to a digital system, comprising a first sensing system for sensing a user interaction of a first type, co-located with a second sensing system for sensing a user interaction of a second type. The first system may detect styluses and like objects using EM radiation and the second system may detect touch pressure.

Abstract: A digitizer for user interaction via an object with an electronically refreshable display screen, the digitizer comprising: a transparent sensing arrangement of detectors located at said electronically refreshable display screen for detecting an electric field of said object, said detectors having outputs, and an arrangement of differential amplifiers associated with said outputs, thereby to apply differential detection between said outputs.

Abstract: A device for detecting physical objects, each object having a detectable identifier, the objects being disposed in association with a graphic display device, comprising a detector operable to detect a location of said identifier relative to said graphic display device, and to output a signal bearing information of said first location, wherein said device is operable to determine, by electronic processing, from said signal, a relative location of said physical object in relation to said graphic display device.

Abstract: Apparatus for user input to a digital system, comprising a first sensing system for sensing a user interaction of a first type, co-located with a second sensing system for sensing a user interaction of a second type. The first system may detect styluses and like objects using EM radiation and the second system may detect touch pressure.