Abstract: In infrared touch input devices that detect and locate a touch object from the blocking of light paths propagating along the X,Y axes, an ambiguity arises when two touch objects are present. This ambiguity can be resolved by the provision of additional light paths angled to the X,Y axes. The present invention provides projection systems that include a light splitting element for splitting collimated sheet of light into two or more sets of beam paths, thereby providing the additional light paths for resolving the double touch ambiguity. In preferred embodiments the light splitting element is in the form of a prism film.

Abstract: In infrared touch input devices that detect and locate a touch object from the blocking of light paths propagating along the X,Y axes, an ambiguity arises when two touch objects are present. This ambiguity can be resolved by the provision of additional light paths angled to the X,Y axes. The present invention provides projection systems that include a light splitting element for splitting collimated sheet of light into two or more sets of beam paths, thereby providing the additional light paths for resolving the double touch ambiguity. In preferred embodiments the light splitting element is in the form of a prism film.

Abstract: The invention describes various optical waveguide layouts with reduced substrate area, with particular application to reducing bezel width in optical touch systems. In certain preferred embodiments the optical waveguide layouts include a plurality of waveguide crossings.

Abstract: A data input apparatus having at least one transmit element coupled to a source of light of a predetermined wavelength, at least one light receive element and a detection device to detect interruption of beams of the light of said predetermined wavelength extending from said transmit element to said receive element wherein at least one of said transmit element and said receive element comprises at least one waveguide having a light transmitting core and a non-core portion and one or mote discontinuance means adapted to reduce transmission of stray light within the non-core portion. The discontinuance is adapted to scatter, absorb, divert or block stray light and can be applied to one or mote of the upper cladding, lower cladding, substrate or common base.