Abstract: A dual light-source position detecting system for use in touch screens is provided that utilizes parallax to determine the position of an interposing object, and a prismatic film that is brightly retroreflective over a broad entrance angle to enhance to accuracy of the parallax determination of position. The position detecting system includes at least one camera positioned to receive light radiation traversing a detection area and that generates a signal representative of an image; two spaced-apart sources of light radiation, which may be LEDs, or IR emitters positioned adjacent to the camera for outputting light radiation that overlaps over at least a portion of a detection area, and a prismatic film positioned along a periphery of at least a portion of the detection area that retroreflects the light radiation from the two sources to the camera.

Abstract: A touch screen system and prismatic film includes a retroreflective substrate having a plurality of retroreflective elements having triangular cube corners. A metallized layer is disposed over at least a portion of the retroreflective elements. In one embodiment, the prismatic film includes two colored substrates mounted over the retroreflective elements. In another embodiment, a single substrate is mounted over the retroreflective elements. It is often desired that a color of the substrate(s) be chosen that is highly transparent in the infrared spectrum, but is also non-transparent in the visible light spectrum, giving the prismatic film a dark appearance. The prismatic film includes a plurality of retroreflective elements having triangular cube corners with a cant in a range between about 4 degrees in a face more parallel direction to 18 degrees in an edge more parallel direction and a cube depth between about 0.002 and 0.008 inches or with a cant of about 5.

Abstract: A dual light-source position detecting system for use in touch screens is provided that utilizes parallax to determine the position of an interposing object, and a prismatic film that is brightly retroreflective over a broad entrance angle to enhance to accuracy of the parallax determination of position. The position detecting system includes at least one camera positioned to receive light radiation traversing a detection area and that generates a signal representative of an image; two spaced-apart sources of light radiation, which may be LEDs, or IR emitters positioned adjacent to the camera for outputting light radiation that overlaps over at least a portion of a detection area, and a prismatic film positioned along a periphery of at least a portion of the detection area that retroreflects the light radiation from the two sources to the camera.

Abstract: A touch screen system and prismatic film includes a retroreflective substrate having a plurality of retroreflective elements having triangular cube corners. A metallized layer is disposed over at least a portion of the retroreflective elements. In one embodiment, the prismatic film includes two colored substrates mounted over the retroreflective elements. In another embodiment, a single substrate is mounted over the retroreflective elements. It is often desired that a color of the substrate(s) be chosen that is highly transparent in the infrared spectrum, but is also non-transparent in the visible light spectrum, giving the prismatic film a dark appearance. The prismatic film includes a plurality of retroreflective elements having triangular cube corners with a cant in a range between about 4 degrees in a face more parallel direction to 18 degrees in an edge more parallel direction and a cube depth between about 0.002 and 0.008 inches or with a cant of about 5.

Abstract: The present invention relates to a timing system including an integrated circuit having an oscillator that provides both high and low frequency clock signals from a single high frequency crystal without the necessity of a tuning fork crystal. The low frequency signal is available for time-keeping applications, with low power consumption during “idle” periods. The high performance high frequency signal is available on demand for clock and frequency reference use. The oscillator of the present invention provides improved time-keeping accuracy, whilst size, cost and component count is reduced. Furthermore, phase noise and other critical parameters of the high frequency oscillator are not compromised. Shock vulnerability, a known problem for tuning fork crystals, is reduced.