Patent ID: 7515143
Filing Date: 2009-04-07
Classification: G06F

Abstract:
1. A method for providing substantially uniform illumination of a liquid crystal display (LCD) panel that is located at a viewing surface of an interactive display, whereby the LCD panel is uniformly illuminated such that graphical output of the LCD panel is homogenously illuminated and visible to a user, regardless of the user's viewing angle with respect to the viewing surface and without the effects of parallax that may otherwise cause the user to perceive darkened areas in the LCD panel when viewing the interactive display from certain angles, and for detecting objects that are in contact with or in close proximity to a user interface layer of the viewing surface of the interactive display, comprising the steps of: (a) illuminating the LCD panel of the interactive display with visible light that has been emitted and diffused by an illumination system, and such that illumination of the LCD panel and of the corresponding viewing surface of the interactive display is substantially uniform when the viewing surface of the interactive display is viewed from a plurality of substantially different viewing angles, wherein the illumination system used to illuminate the LCD panel with visible light in a substantially uniform manner comprises: wherein the visible light for illumination of the LCD panel is generated by the following: (b) diffusing the visible light received at the viewing surface of the interactive display with a layer of diffusing material such that an object below the viewing surface of the interactive display is at least partially obscured from view by the user; and (c) illuminating the viewing surface of the interactive display with non-visible light for use in detecting objects disposed in contact with or adjacent to the user interface layer of the viewing surface, wherein the viewing surface of the interactive display is composed of materials that are substantially transparent to the non-visible light such that reflected non-visible light, which has passed through the viewing surface of the interactive display and has been reflected back into the interactive display from the objects in contact with or adjacent to the user interface layer of the viewing surface, is detected.