Abstract: A touch screen such as an electronic whiteboard that detects the size of a touch as well as the touch's location on the touch screen. The size of the touch or a stylus mode based on the size of the touch is then reported to an application program by the touch screen and the application program uses the size or mode to determine what operation is to be performed at the location of the touch. In the exemplary implementation, the size of the touch determines whether the stylus mode is erasing or non-erasing. A user of the touch screen can thus switch from writing to erasing simply by switching from a marking pen to an eraser that is broader than the marking pen. In the exemplary implementation, the touch panel is a resistive membrane touch panel and touch size is detected from a touch resistance that is determined by subtracting other components of the total resistance of a circuit that arises when the touch panel is touched.

Abstract: A technique for building touch-sensitive panels which permits construction of large, low-cost electronic whiteboards with improved feel. The electronic whiteboards are of the resistive membrane type, in which a touch on a flexible membrane causes the membrane to come into contact with a surface and that in turn changes the resistances across the membrane and the surface, permitting determination of the location of the touch. A gap between the flexible membrane and the surface is maintained primarily by the use of relatively large spacing structures located between the membrane and the surface, instead of by tension on the membrane. The use of large spacing structures permits the surface to be made using relatively irregular and therefore low-cost material. The spacing structures are backed by an elastic layer, which permits the spacing structures to yield to a touch on the screen.

Abstract: An electronic whiteboard is coupled to a computer which receives information from the whiteboard indicative of graphical user inputs entered via a writing region of the whiteboard and control inputs entered via a control region of the whiteboard. A driver executing on the computer receives the information transmitted by the whiteboard, performs certain actions on the received information and causes an application program to retrieve the information and store the information to a session file. The application provides a user interface which allows a user to view images generated on the whiteboard, store such images, view previously stored images and to manipulate the images in a variety of ways.