TOUCHSCREEN SYSTEM USABLE IN A VARIETY OF MEDIA

摘要

An optical touch screen, suitable for use underwater and in air comprises a transparent waveguide covering an optional display, which is surrounded by light sources that couple light into the waveguide and sensors that monitor the intensity of light propagating through the waveguide, where light intensity responses are attenuated when the touch surface of the waveguide is touched, as result of disturbing (or frustrating) internally reflected light, and where the locations of such touch events are determined using line equations. The optical touch screen system implements various techniques to allow housing in a waterproof case, and seamless, reliable function underwater and in air.

主权项

1. A method for determining touch location on a touch screen, comprising:
surrounding a waveguide with a waterproof housing; emitting a radiation pulse through the waveguide from one or more of a plurality of radiation sources coupled with a lower surface of the waveguide; forming a radiation response profile from the attenuation of each radiation pulse emitted from the plurality of radiation sources, internally reflected through the waveguide and measured at one or more radiation sensors coupled with the lower surface of the waveguide interior to at least one perimeter surface of the waveguide; determining a response centroid from the radiation response profile; constructing a line equation defining the path between each response centroid and the emitting radiation source such that each line equation extends at an angle relative to every other line equation; calculating points of interception for the line equations; and computing a centroid of the points of interception to establish a valid touch location.