Abstract: An interactive input system comprises an optical waveguide, a radiation source directing radiation into the optical waveguide, the radiation undergoing total internal reflection within the optical waveguide in response to at least one touch input on a surface of the optical waveguide. At least one imaging device is positioned adjacent to the waveguide, the at least one imaging device having a field of view looking inside the optical waveguide and capturing image frames thereof. Processing structure processes the image frames captured by the at least one imaging device to determine a location of the at least one touch input based on a frequency of reflections of the radiation appearing in the image frame.

Abstract: An interactive input system comprises an optical waveguide, a radiation source directing radiation into the optical waveguide, the radiation undergoing total internal reflection within the optical waveguide in response to at least one touch input on a surface of the optical waveguide. At least one imaging device is positioned adjacent to the waveguide, the at least one imaging device having a field of view looking inside the optical waveguide and capturing image frames thereof. Processing structure processes the image frames captured by the at least one imaging device to determine a location of the at least one touch input based on a frequency of reflections of the radiation appearing in the image frame.

Abstract: An apparatus for detecting a pointer within a region of interest includes at least one pair of imaging devices. The imaging devices have overlapping fields of view encompassing the region of interest. At least one light source provides illumination across the region of interest and is within the field of view of at least one of the imaging device. A filter is associated with the at least one imaging device whose field of view sees the light source. The filter blocks light projected by the light source to inhibit the imaging device from being blinded by the projected light.